Methylamine as a nitrogen source for microorganisms from a coastal marine environment.

PubMed

Taubert, Martin; Grob, Carolina; Howat, Alexandra M; Burns, Oliver J; Pratscher, Jennifer; Jehmlich, Nico; von Bergen, Martin; Richnow, Hans H; Chen, Yin; Murrell, J Colin

2017-06-01

Nitrogen is a key limiting resource for biomass production in the marine environment. Methylated amines, released from the degradation of osmolytes, could provide a nitrogen source for marine microbes. Thus far, studies in aquatic habitats on the utilization of methylamine, the simplest methylated amine, have mainly focussed on the fate of the carbon from this compound. Various groups of methylotrophs, microorganisms that can grow on one-carbon compounds, use methylamine as a carbon source. Non-methylotrophic microorganisms may also utilize methylamine as a nitrogen source, but little is known about their diversity, especially in the marine environment. In this proof-of-concept study, stable isotope probing (SIP) was used to identify microorganisms from a coastal environment that assimilate nitrogen from methylamine. SIP experiments using 15 N methylamine combined with metagenomics and metaproteomics facilitated identification of active methylamine-utilizing Alpha- and Gammaproteobacteria. The draft genomes of two methylamine utilizers were obtained and their metabolism with respect to methylamine was examined. Both bacteria identified in these SIP experiments used the γ-glutamyl-methylamide pathway, found in both methylotrophs and non-methylotrophs, to metabolize methylamine. The utilization of 15 N methylamine also led to the release of 15 N ammonium that was used as nitrogen source by other microorganisms not directly using methylamine. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Stimulation of Microbially Mediated Arsenic Release in Bangladesh Aquifers by Young Carbon Indicated by Radiocarbon Analysis of Sedimentary Bacterial Lipids.

PubMed

Whaley-Martin, K J; Mailloux, B J; van Geen, A; Bostick, B C; Silvern, R F; Kim, C; Ahmed, K M; Choudhury, I; Slater, G F

2016-07-19

The sources of reduced carbon driving the microbially mediated release of arsenic to shallow groundwater in Bangladesh remain poorly understood. Using radiocarbon analysis of phospholipid fatty acids (PLFAs) and potential carbon pools, the abundance and carbon sources of the active, sediment-associated, in situ bacterial communities inhabiting shallow aquifers (<30 m) at two sites in Araihazar, Bangladesh, were investigated. At both sites, sedimentary organic carbon (SOC) Δ(14)C signatures of -631 ± 54‰ (n = 12) were significantly depleted relative to dissolved inorganic carbon (DIC) of +24 ± 30‰ and dissolved organic carbon (DOC) of -230 ± 100‰. Sediment-associated PLFA Δ(14)C signatures (n = 10) at Site F (-167‰ to +20‰) and Site B (-163‰ to +21‰) were highly consistent and indicated utilization of carbon sources younger than the SOC, likely from the DOC pool. Sediment-associated PLFA Δ(14)C signatures were consistent with previously determined Δ(14)C signatures of microbial DNA sampled from groundwater at Site F indicating that the carbon source for these two components of the subsurface microbial community is consistent and is temporally stable over the two years between studies. These results demonstrate that the utilization of relatively young carbon sources by the subsurface microbial community occurs at sites with varying hydrology. Further they indicate that these young carbon sources drive the metabolism of the more abundant sediment-associated microbial communities that are presumably more capable of Fe reduction and associated release of As. This implies that an introduction of younger carbon to as of yet unaffected sediments (such as those comprising the deeper Pleistocene aquifer) could stimulate microbial communities and result in arsenic release.

Dual-Carbon sources fuel the OCS deep-reef Community, a stable isotope investigation

USGS Publications Warehouse

Sulak, Kenneth J.; Berg, J.; Randall, Michael T.; Dennis, George D.; Brooks, R.A.

2008-01-01

The hypothesis that phytoplankton is the sole carbon source for the OCS deep-reef community (>60 m) was tested. Trophic structure for NE Gulf of Mexico deep reefs was analyzed via carbon and nitrogen stable isotopes. Carbon signatures for 114 entities (carbon sources, sediment, fishes, and invertebrates) supported surface phytoplankton as the primary fuel for the deep reef. However, a second carbon source, the macroalga Sargassum, with its epiphytic macroalgal associate, Cladophora liniformis, was also identified. Macroalgal carbon signatures were detected among 23 consumer entities. Most notably, macroalgae contributed 45 % of total carbon to the 13C isotopic spectrum of the particulate-feeding reef-crest gorgonian Nicella. The discontinuous spatial distribution of some sessile deep-reef invertebrates utilizing pelagic macroalgal carbon may be trophically tied to the contagious distribution of Sargassum biomass along major ocean surface features.

Aerobic biodegradation of the sulfonamide antibiotic sulfamethoxazole by activated sludge applied as co-substrate and sole carbon and nitrogen source.

PubMed

Müller, Elisabeth; Schüssler, Walter; Horn, Harald; Lemmer, Hilde

2013-08-01

Potential aerobic biodegradation mechanisms of the widely used polar, low-adsorptive sulfonamide antibiotic sulfamethoxazole (SMX) were investigated in activated sludge at bench scale. The study focused on (i) SMX co-metabolism with acetate and ammonium nitrate and (ii) SMX utilization when present as the sole carbon and nitrogen source. With SMX adsorption being negligible, elimination was primarily based on biodegradation. Activated sludge was able to utilize SMX both as a carbon and/or nitrogen source. SMX biodegradation was enhanced when a readily degradable energy supply (acetate) was provided which fostered metabolic activity. Moreover, it was raised under nitrogen deficiency conditions. The mass balance for dissolved organic carbon showed an incomplete SMX mineralization with two scenarios: (i) with SMX as a co-substrate, 3-amino-5-methyl-isoxazole represented the main stable metabolite and (ii) SMX as sole carbon and nitrogen source possibly yielded hydroxyl-N-(5-methyl-1,2-oxazole-3-yl)benzene-1-sulfonamide as a further metabolite. Copyright © 2013 Elsevier Ltd. All rights reserved.

Isolation and characterization of yeasts capable of efficient utilization of hemicellulosic hydrolyzate as the carbon source.

PubMed

Cassa-Barbosa, L A; Procópio, R E L; Matos, I T S R; Filho, S A

2015-09-28

Few yeasts have shown the potential to efficiently utilize hemicellulosic hydrolyzate as the carbon source. In this study, microorganisms isolated from the Manaus region in Amazonas, Brazil, were characterized based on their utilization of the pentoses, xylose, and arabinose. The yeasts that showed a potential to assimilate these sugars were selected for the better utilization of lignocellulosic biomass. Two hundred and thirty seven colonies of unicellular microorganisms grown on hemicellulosic hydrolyzate, xylose, arabinose, and yeast nitrogen base selective medium were analyzed. Of these, 231 colonies were subjected to sugar assimilation tests. One hundred and twenty five of these were shown to utilize hydrolyzed hemicellulose, xylose, or arabinose as the carbon source for growth. The colonies that showed the best growth (N = 57) were selected, and their internal transcribed spacer-5.8S rDNA was sequenced. The sequenced strains formed four distinct groups in the phylogenetic tree, and showed a high percentage of similarity with Meyerozyma caribbica, Meyerozyma guilliermondii, Trichosporon mycotoxinivorans, Trichosporon loubieri, Pichia kudriavzevii, Candida lignohabitans, and Candida ethanolica. The discovery of these xylose-fermenting yeasts could attract widespread interest, as these can be used in the cost-effective production of liquid fuel from lignocellulosic materials.

Insights into the simultaneous utilization of glucose and glycerol by Streptomyces albulus M-Z18 for high ε-poly-L-lysine productivity.

PubMed

Zeng, Xin; Zhao, Junjie; Chen, Xusheng; Mao, Zhonggui; Miao, Wenyun

2017-12-01

The simultaneous consumption of glucose and glycerol led to remarkably higher productivity of both biomass and ε-poly-L-lysine (ε-PL), which was of great significance in industrial microbial fermentation. To further understand the superior fermentation performances, transcriptional analysis and exogenous substrates addition were carried out to study the simultaneous utilization of glucose and glycerol by Streptomyces albulus M-Z18. Transcriptome analysis revealed that there was no mutual transcriptional suppression between the utilization of glucose and glycerol, which was quite different from typical "glucose effect". In addition, microorganisms cultivated with single glycerol showed significant demand for ribose-5-phosphate, which resulted in potential demand for glucose and xylitol. The above demand could be relieved by glucose (in the mixed carbon source) or xylitol addition, leading to improvement of biomass production. It indicated that glucose in the mixed carbon source was more important for biomass production. Besides, transcriptional analysis and exogenous citrate addition proved that single carbon sources could not afford enough carbon skeletons for Embden Meyerhof pathway (EMP) while a glucose-glycerol combination could provided sufficient carbon skeletons to saturate the metabolic capability of EMP, which contributed to the replenishment of precursors and energy consumed in ε-PL production. This study offered insight into the simultaneous consumption of glucose and glycerol in the ε-PL batch fermentation, which deepened our comprehension on the high ε-PL productivity in the mixed carbon source.

Mutations in Alternative Carbon Utilization Pathways in Candida albicans Attenuate Virulence and Confer Pleiotropic Phenotypes▿

PubMed Central

Ramírez, Melissa A.; Lorenz, Michael C.

2007-01-01

The interaction between Candida albicans and cells of the innate immune system is a key determinant of disease progression. Transcriptional profiling has revealed that C. albicans has a complex response to phagocytosis, much of which is similar to carbon starvation. This suggests that nutrient limitation is a significant stress in vivo, and we have shown that glyoxylate cycle mutants are less virulent in mice. To examine whether other aspects of carbon metabolism are important in vivo during an infection, we have constructed strains lacking FOX2 and FBP1, which encode key components of fatty acid β-oxidation and gluconeogenesis, respectively. As expected, fox2Δ mutants failed to utilize several fatty acids as carbon sources. Surprisingly, however, these mutants also failed to grow in the presence of several other carbon sources, whose assimilation is independent of β-oxidation, including ethanol and citric acid. Mutants lacking the glyoxylate enzyme ICL1 also had more severe carbon utilization phenotypes than were expected. These results suggest that the regulation of alternative carbon metabolism in C. albicans is significantly different from that in other fungi. In vivo, fox2Δ mutants show a moderate but significant reduction in virulence in a mouse model of disseminated candidiasis, while disruption of the glyoxylate cycle or gluconeogenesis confers a severe attenuation in this model. These data indicate that C. albicans often encounters carbon-poor conditions during growth in the host and that the ability to efficiently utilize multiple nonfermentable carbon sources is a virulence determinant. Consistent with this in vivo requirement, C. albicans uniquely regulates carbon metabolism in a more integrated manner than in Saccharomyces cerevisiae, such that defects in one part of the machinery have wider impacts than expected. These aspects of alternative carbon metabolism may then be useful as targets for therapeutic intervention. PMID:17158734

Galactose utilization sheds new light on sugar metabolism in the sequenced strain Dekkera bruxellensis CBS 2499.

PubMed

Moktaduzzaman, Md; Galafassi, Silvia; Capusoni, Claudia; Vigentini, Ileana; Ling, Zhihao; Piškur, Jure; Compagno, Concetta

2015-03-01

Dekkera bruxellensis and Saccharomyces cerevisiae are considered two phylogenetically distant relatives, but they share several industrial relevant traits such as the ability to produce ethanol under aerobic conditions (Crabtree effect), high tolerance towards ethanol and acids, and ability to grow without oxygen. Beside a huge adaptability, D. bruxellensis exhibits a broader spectrum in utilization of carbon and nitrogen sources in comparison to S. cerevisiae. With the aim to better characterize its carbon source metabolism and regulation, the usage of galactose and the role that glucose plays on sugar metabolism were investigated in D. bruxellensis CBS 2499. The results indicate that in this yeast galactose is a non-fermentable carbon source, in contrast to S. cerevisiae that can ferment it. In particular, its metabolism is affected by the nitrogen source. Interestingly, D. bruxellensis CBS 2499 exhibits the 'short-term Crabtree effect', and the expression of genes involved in galactose utilization and in respiratory metabolism is repressed by glucose, similarly to what occurs in S. cerevisiae. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

The energy and emissions footprint of water supply for Southern California

NASA Astrophysics Data System (ADS)

Fang, A. J.; Newell, Joshua P.; Cousins, Joshua J.

2015-11-01

Due to climate change and ongoing drought, California and much of the American West face critical water supply challenges. California’s water supply infrastructure sprawls for thousands of miles, from the Colorado River to the Sacramento Delta. Bringing water to growing urban centers in Southern California is especially energy intensive, pushing local utilities to balance water security with factors such as the cost and carbon footprint of the various supply sources. To enhance water security, cities are expanding efforts to increase local water supply. But do these local sources have a smaller carbon footprint than imported sources? To answer this question and others related to the urban water-energy nexus, this study uses spatially explicit life cycle assessment to estimate the energy and emissions intensity of water supply for two utilities in Southern California: Los Angeles Department of Water and Power, which serves Los Angeles, and the Inland Empire Utility Agency, which serves the San Bernardino region. This study differs from previous research in two significant ways: (1) emissions factors are based not on regional averages but on the specific electric utility and generation sources supplying energy throughout transport, treatment, and distribution phases of the water supply chain; (2) upstream (non-combustion) emissions associated with the energy sources are included. This approach reveals that in case of water supply to Los Angeles, local recycled water has a higher carbon footprint than water imported from the Colorado River. In addition, by excluding upstream emissions, the carbon footprint of water supply is potentially underestimated by up to 30%. These results have wide-ranging implications for how carbon footprints are traditionally calculated at local and regional levels. Reducing the emissions intensity of local water supply hinges on transitioning the energy used to treat and distribute water away from fossil fuel, sources such as coal.

Exploring cover crops as carbon sources for anaerobic soil disinfestation in a vegetable production system

USDA-ARS?s Scientific Manuscript database

In a raised-bed plasticulture vegetable production system utilizing anaerobic soil disinfestation (ASD) in Florida field trials, pathogen, weed, and parasitic nematode control was equivalent to or better than the methyl bromide control. Molasses was used as the labile carbon source to stimulate micr...

Establishing a synergetic carbon utilization mechanism for non-catabolic use of glucose in microbial synthesis of trehalose.

PubMed

Wu, Yifei; Sun, Xinxiao; Lin, Yuheng; Shen, Xiaolin; Yang, Yaping; Jain, Rachit; Yuan, Qipeng; Yan, Yajun

2017-01-01

In nature glucose is a common carbon and energy source for catabolic use and also a building unit of polysaccharides and glycosylated compounds. The presence of strong glucose catabolic pathways in microorganism rapidly decomposes glucose into smaller metabolites and challenges non-catabolic utilization of glucose as C6 building unit or precursor. To address this dilemma, we design a synergetic carbon utilization mechanism (SynCar), in which glucose catabolism is inactivated and a second carbon source (e.g. glycerol) is employed to maintain cell growth and rationally strengthen PEP driving force for glucose uptake and non-catabolic utilization. Remarkably, a trehalose biosynthesis model developed for proof-of-concept indicates that SynCar leads to 131% and 200% improvement in trehalose titer and yield, respectively. The conversion rate of glucose to trehalose reaches 91% of the theoretical maximum. This work demonstrates the broad applicability of SynCar in the biosynthesis of molecules derived from non-catabolic glucose. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Colwellia psychrerythraea strains from distant deep sea basins show adaptation to local conditions

DOE PAGES

Techtmann, Stephen M.; Fitzgerald, Kathleen S.; Stelling, Savannah C.; ...

2016-05-09

Many studies have shown that microbes, which share nearly identical 16S rRNA genes, can have highly divergent genomes. Microbes from distinct parts of the ocean also exhibit biogeographic patterning. Here in this study we seek to better understand how certain microbes from the same species have adapted for growth under local conditions. The phenotypic and genomic heterogeneity of three strains of Colwellia psychrerythraea was investigated in order to understand adaptions to local environments. Colwellia are psychrophilic heterotrophic marine bacteria ubiquitous in cold marine ecosystems. We have recently isolated two Colwellia strains: ND2E from the Eastern Mediterranean and GAB14E from themore » Great Australian Bight. The 16S rRNA sequence of these two strains were greater than 98.2% identical to the well-characterized C. psychrerythraea 34H, which was isolated from arctic sediments. Salt tolerance, and carbon source utilization profiles for these strains were determined using Biolog Phenotype MicoArrays. These strains exhibited distinct salt tolerance, which was not associated with the salinity of sites of isolation. The carbon source utilization profiles were distinct with less than half of the tested carbon sources being metabolized by all three strains. Whole genome sequencing revealed that the genomes of these three strains were quite diverse with some genomes having up to 1600 strain-specific genes. Many genes involved in degrading strain-specific carbon sources were identified. Finally, there appears to be a link between carbon source utilization and location of isolation with distinctions observed between the Colwellia isolate recovered from sediment compared to water column isolates.« less

A fungal transcription factor essential for starch degradation affects integration of carbon and nitrogen metabolism

DOE PAGES

Xiong, Yi; Wu, Vincent W.; Lubbe, Andrea; ...

2017-05-03

In Neurospora crassa, the transcription factor COL-26 functions as a regulator of glucose signaling and metabolism. Its loss leads to resistance to carbon catabolite repression. Here, we report that COL-26 is necessary for the expression of amylolytic genes in N. crassa and is required for the utilization of maltose and starch. Additionally, the Δcol-26 mutant shows growth defects on preferred carbon sources, such as glucose, an effect that was alleviated if glutamine replaced ammonium as the primary nitrogen source. This rescue did not occur when maltose was used as a sole carbon source. Transcriptome and metabolic analyses of the Δcol-26more » mutant relative to its wild type parental strain revealed that amino acid and nitrogen metabolism, the TCA cycle and GABA shunt were adversely affected. Phylogenetic analysis showed a single col-26 homolog in Sordariales, Ophilostomatales, and the Magnaporthales, but an expanded number of col-26 homologs in other filamentous fungal species. Deletion of the closest homolog of col-26 in Trichoderma reesei, bglR, resulted in a mutant with similar preferred carbon source growth deficiency, and which was alleviated if glutamine was the sole nitrogen source, suggesting conservation of COL-26 and BglR function. Our finding provides novel insight into the role of COL-26 for utilization of starch and in integrating carbon and nitrogen metabolism for balanced metabolic activities for optimal carbon and nitrogen distribution.« less

A fungal transcription factor essential for starch degradation affects integration of carbon and nitrogen metabolism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, Yi; Wu, Vincent W.; Lubbe, Andrea

In Neurospora crassa, the transcription factor COL-26 functions as a regulator of glucose signaling and metabolism. Its loss leads to resistance to carbon catabolite repression. Here, we report that COL-26 is necessary for the expression of amylolytic genes in N. crassa and is required for the utilization of maltose and starch. Additionally, the Δcol-26 mutant shows growth defects on preferred carbon sources, such as glucose, an effect that was alleviated if glutamine replaced ammonium as the primary nitrogen source. This rescue did not occur when maltose was used as a sole carbon source. Transcriptome and metabolic analyses of the Δcol-26more » mutant relative to its wild type parental strain revealed that amino acid and nitrogen metabolism, the TCA cycle and GABA shunt were adversely affected. Phylogenetic analysis showed a single col-26 homolog in Sordariales, Ophilostomatales, and the Magnaporthales, but an expanded number of col-26 homologs in other filamentous fungal species. Deletion of the closest homolog of col-26 in Trichoderma reesei, bglR, resulted in a mutant with similar preferred carbon source growth deficiency, and which was alleviated if glutamine was the sole nitrogen source, suggesting conservation of COL-26 and BglR function. Our finding provides novel insight into the role of COL-26 for utilization of starch and in integrating carbon and nitrogen metabolism for balanced metabolic activities for optimal carbon and nitrogen distribution.« less

A fungal transcription factor essential for starch degradation affects integration of carbon and nitrogen metabolism

PubMed Central

Xiong, Yi; Qin, Lina; Kennedy, Megan; Bauer, Diane; Barry, Kerrie; Northen, Trent R.; Grigoriev, Igor V.

2017-01-01

In Neurospora crassa, the transcription factor COL-26 functions as a regulator of glucose signaling and metabolism. Its loss leads to resistance to carbon catabolite repression. Here, we report that COL-26 is necessary for the expression of amylolytic genes in N. crassa and is required for the utilization of maltose and starch. Additionally, the Δcol-26 mutant shows growth defects on preferred carbon sources, such as glucose, an effect that was alleviated if glutamine replaced ammonium as the primary nitrogen source. This rescue did not occur when maltose was used as a sole carbon source. Transcriptome and metabolic analyses of the Δcol-26 mutant relative to its wild type parental strain revealed that amino acid and nitrogen metabolism, the TCA cycle and GABA shunt were adversely affected. Phylogenetic analysis showed a single col-26 homolog in Sordariales, Ophilostomatales, and the Magnaporthales, but an expanded number of col-26 homologs in other filamentous fungal species. Deletion of the closest homolog of col-26 in Trichoderma reesei, bglR, resulted in a mutant with similar preferred carbon source growth deficiency, and which was alleviated if glutamine was the sole nitrogen source, suggesting conservation of COL-26 and BglR function. Our finding provides novel insight into the role of COL-26 for utilization of starch and in integrating carbon and nitrogen metabolism for balanced metabolic activities for optimal carbon and nitrogen distribution. PMID:28467421

Carbon source and irrigation evaluation for anaerobic soil disinfestation in southern California

USDA-ARS?s Scientific Manuscript database

Water use efficiency and utilization of feasible carbon sources have been important factors for successful implementation and adoption of ASD in California and are the focus of current research. In the 2014-15 study at Santa Paula, CA we compared ASD with 9 t of rice bran bed-incorporated with eith...

Electrosynthesis of enaminones directly from methyl ketones and amines with nitromethane as a carbon source.

PubMed

Xu, Kun; Zhang, Zhenlei; Qian, Peng; Zha, Zhenggen; Wang, Zhiyong

2015-07-14

An efficient and mechanistically different method for the electrosynthesis of enaminone directly from methyl ketones, amines and nitromethane was developed. This transition-metal-free method proceeded at room temperature to give a wide array of enaminones in one step, utilizing nitromethane as the carbon source.

Growth of Prototheca isolates on n-hexadecane and mixed-hydrocarbon substrate.

PubMed Central

Walker, J D; Pore, R S

1978-01-01

Prototheca zopfii, an achlorphyllous alga, was capable of using hydrocarbons as sole carbon and energy source. The ability of P. zopfii to use hydrocarbons did not correlate with source of isolation. Seventy-five percent of the P. zopfii cultures recovered from sewage, plants, or animals utilized hydrocarbons. Other Prototheca species and P. zopfii that did not utilize hydrocarbons were isolated simultaneously from several sources with isolates that did use hydrocarbons. Species type rather than source of isolation was the predominant factor that determined hydrocarbon utilization. PMID:565616

Generation, capture, and utilization of industrial carbon dioxide.

PubMed

Hunt, Andrew J; Sin, Emily H K; Marriott, Ray; Clark, James H

2010-03-22

As a carbon-based life form living in a predominantly carbon-based environment, it is not surprising that we have created a carbon-based consumer society. Our principle sources of energy are carbon-based (coal, oil, and gas) and many of our consumer goods are derived from organic (i.e., carbon-based) chemicals (including plastics, fabrics and materials, personal care and cleaning products, dyes, and coatings). Even our large-volume inorganic-chemicals-based industries, including fertilizers and construction materials, rely on the consumption of carbon, notably in the form of large amounts of energy. The environmental problems which we now face and of which we are becoming increasingly aware result from a human-induced disturbance in the natural carbon cycle of the Earth caused by transferring large quantities of terrestrial carbon (coal, oil, and gas) to the atmosphere, mostly in the form of carbon dioxide. Carbon is by no means the only element whose natural cycle we have disturbed: we are transferring significant quantities of elements including phosphorus, sulfur, copper, and platinum from natural sinks or ores built up over millions of years to unnatural fates in the form of what we refer to as waste or pollution. However, our complete dependence on the carbon cycle means that its disturbance deserves special attention, as is now manifest in indicators such as climate change and escalating public concern over global warming. As with all disturbances in materials balances, we can seek to alleviate the problem by (1) dematerialization: a reduction in consumption; (2) rematerialization: a change in what we consume; or (3) transmaterialization: changing our attitude towards resources and waste. The "low-carbon" mantra that is popularly cited by organizations ranging from nongovernmental organizations to multinational companies and from local authorities to national governments is based on a combination of (1) and (2) (reducing carbon consumption though greater efficiency and lower per capita consumption, and replacing fossil energy sources with sources such as wind, wave, and solar, respectively). "Low carbon" is of inherently less value to the chemical and plastics industries at least in terms of raw materials although a version of (2), the use of biomass, does apply, especially if we use carbon sources that are renewable on a human timescale. There is however, another renewable, natural source of carbon that is widely available and for which greater utilization would help restore material balance and the natural cycle for carbon in terms of resource and waste. CO(2), perhaps the most widely discussed and feared chemical in modern society, is as fundamental to our survival as water, and like water we need to better understand the human as well as natural production and consumption of CO(2) so that we can attempt to get these into a sustainable balance. Current utilization of this valuable resource by the chemical industry is only 90 megatonne per year, compared to the 26.3 gigatonne CO(2) generated annually by combustion of fossil fuels for energy generation, as such significant opportunities exist for increased utilization of CO(2) generated from industrial processes. It is also essential that renewable energy is used if CO(2) is to be utilized as a C1 building block.

Electrochemical process for the preparation of nitrogen fertilizers

DOEpatents

Aulich, Ted R [Grand Forks, ND; Olson, Edwin S [Grand Forks, ND; Jiang, Junhua [Grand Forks, ND

2012-04-10

The present invention provides methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia, at low temperature and pressure, preferably at ambient temperature and pressure, utilizing a source of carbon, a source of nitrogen, and/or a source of hydrogen or hydrogen equivalent. Implementing an electrolyte serving as ionic charge carrier, (1) ammonium nitrate is produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers are produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source; (3) ammonia is produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source or a hydrogen equivalent such as carbon monoxide or a mixture of carbon monoxide and hydrogen at the anode; and (4) urea-ammonium nitrate is produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source. The electrolyte can be aqueous, non-aqueous, or solid.

Proteome Analyses of Hydrogen-producing Hyperthermophilic Archaeon Thermococcus onnurineus NA1 in Different One-carbon Substrate Culture Conditions*

PubMed Central

Moon, Yoon-Jung; Kwon, Joseph; Yun, Sung-Ho; Lim, Hye Li; Kim, Min-Sik; Kang, Sung Gyun; Lee, Jung-Hyun; Choi, Jong-Soon; Kim, Seung Il; Chung, Young-Ho

2012-01-01

Thermococcus onnurineus NA1, a sulfur-reducing hyperthermophilic archaeon, is capable of H2-producing growth, considered to be hydrogenogenic carboxydotrophy. Utilization of formate as a sole energy source has been well studied in T. onnurineus NA1. However, whether formate can be used as its carbon source remains unknown. To obtain a global view of the metabolic characteristics of H2-producing growth, a quantitative proteome analysis of T. onnurineus NA1 grown on formate, CO, and starch was performed by combining one-dimensional SDS-PAGE with nano UPLC-MSE. A total of 587 proteins corresponding to 29.7% of the encoding genes were identified, and the major metabolic pathways (especially energy metabolism) were characterized at the protein level. Expression of glycolytic enzymes was common but more highly induced in starch-grown cells. In contrast, enzymes involved in key steps of the gluconeogenesis and pentose phosphate pathways were strongly up-regulated in formate-grown cells, suggesting that formate could be utilized as a carbon source by T. onnurineus NA1. In accordance with the genomic analysis, comprehensive proteomic analysis also revealed a number of hydrogenase clusters apparently associated with formate metabolism. On the other hand, CODH and CO-induced hydrogenases belonging to the Hyg4-II cluster, as well as sulfhydrogenase-I and Mbx, were prominently expressed during CO culture. Our data suggest that CO can be utilized as a sole energy source for H2 production via an electron transport mechanism and that CO2 produced from catabolism or CO oxidation by CODH and CO-induced hydrogenases may subsequently be assimilated into the organic carbon. Overall, proteomic comparison of formate- and CO-grown cells with starch-grown cells revealed that a single carbon compound, such as formate and CO, can be utilized as an efficient substrate to provide cellular carbon and/or energy by T. onnurineus NA1. PMID:22232491

Use of food waste-recycling wastewater as an alternative carbon source for denitrification process: A full-scale study.

PubMed

Kim, Eunji; Shin, Seung Gu; Jannat, Md Abu Hanifa; Tongco, Jovale Vincent; Hwang, Seokhwan

2017-12-01

Using organic wastes as an alternative to commercial carbon sources could be beneficial by reducing costs and environmental impacts. In this study, food waste-recycling wastewater (FRW) was evaluated as an alternative carbon source for biological denitrification over a period of seven months in a full-scale sewage wastewater treatment plant. The denitrification performance was stable with a mean nitrate removal efficiency of 97.2%. Propionate was initially the most persistent volatile fatty acid, but was completely utilized after 19days. Eubacteriacea, Saprospiraceae, Rhodocyclaceae and Comamonadaceae were the major bacterial families during FRW treatment and were regarded as responsible for hydrolysis (former two) and nitrate removal (latter two) of FRW. These results demonstrate that FRW can be an effective external carbon source; process stabilization was linked to the acclimation and function of bacterial populations to the change of carbon source. Copyright © 2017 Elsevier Ltd. All rights reserved.

Review: role of carbon sources for in vitro plant growth and development.

PubMed

Yaseen, Mehwish; Ahmad, Touqeer; Sablok, Gaurav; Standardi, Alvaro; Hafiz, Ishfaq Ahmad

2013-04-01

In vitro plant cells, tissues and organ cultures are not fully autotrophic establishing a need for carbohydrates in culture media to maintain the osmotic potential, as well as to serve as energy and carbon sources for developmental processes including shoot proliferation, root induction as well as emission, embryogenesis and organogenesis, which are highly energy demanding developmental processes in plant biology. A variety of carbon sources (both reducing and non-reducing) are used in culture media depending upon genotypes and specific stages of growth. However, sucrose is most widely used as a major transport-sugar in the phloem sap of many plants. In micropropagation systems, morphogenetic potential of plant tissues can greatly be manipulated by varying type and concentration of carbon sources. The present article reviews the past and current findings on carbon sources and their sustainable utilization for in vitro plant tissue culture to achieve better growth rate and development.

STABLE CARBON ISOTOPE EVIDENCE FOR COUPLING BETWEEN SEDIMENTARY BACTERIA AND SEAGRASSES IN A SUB-TROPICAL LAGOON

EPA Science Inventory

We measured stable carbon isotope ratios (d13C) in phospholipid fatty acids (PLFAs) to identify the primary carbon source utilized by sedimentary bacteria in Lower Laguna Madre, Texas, which is a seagrass dominated lagoon. Comparisons were made between three differing habitat ty...

Spatial differentiation of gene expression in Aspergillus niger colony grown for sugar beet pulp utilization

PubMed Central

Benoit, Isabelle; Zhou, Miaomiao; Vivas Duarte, Alexandra; Downes, Damien J.; Todd, Richard B.; Kloezen, Wendy; Post, Harm; Heck, Albert J. R.; Maarten Altelaar, A. F.; de Vries, Ronald P.

2015-01-01

Degradation of plant biomass to fermentable sugars is of critical importance for the use of plant materials for biofuels. Filamentous fungi are ubiquitous organisms and major plant biomass degraders. Single colonies of some fungal species can colonize massive areas as large as five soccer stadia. During growth, the mycelium encounters heterogeneous carbon sources. Here we assessed whether substrate heterogeneity is a major determinant of spatial gene expression in colonies of Aspergillus niger. We analyzed whole-genome gene expression in five concentric zones of 5-day-old colonies utilizing sugar beet pulp as a complex carbon source. Growth, protein production and secretion occurred throughout the colony. Genes involved in carbon catabolism were expressed uniformly from the centre to the periphery whereas genes encoding plant biomass degrading enzymes and nitrate utilization were expressed differentially across the colony. A combined adaptive response of carbon-catabolism and enzyme production to locally available monosaccharides was observed. Finally, our results demonstrate that A. niger employs different enzymatic tools to adapt its metabolism as it colonizes complex environments. PMID:26314379

Spatial differentiation of gene expression in Aspergillus niger colony grown for sugar beet pulp utilization.

PubMed

Benoit, Isabelle; Zhou, Miaomiao; Vivas Duarte, Alexandra; Downes, Damien J; Todd, Richard B; Kloezen, Wendy; Post, Harm; Heck, Albert J R; Maarten Altelaar, A F; de Vries, Ronald P

2015-08-28

Degradation of plant biomass to fermentable sugars is of critical importance for the use of plant materials for biofuels. Filamentous fungi are ubiquitous organisms and major plant biomass degraders. Single colonies of some fungal species can colonize massive areas as large as five soccer stadia. During growth, the mycelium encounters heterogeneous carbon sources. Here we assessed whether substrate heterogeneity is a major determinant of spatial gene expression in colonies of Aspergillus niger. We analyzed whole-genome gene expression in five concentric zones of 5-day-old colonies utilizing sugar beet pulp as a complex carbon source. Growth, protein production and secretion occurred throughout the colony. Genes involved in carbon catabolism were expressed uniformly from the centre to the periphery whereas genes encoding plant biomass degrading enzymes and nitrate utilization were expressed differentially across the colony. A combined adaptive response of carbon-catabolism and enzyme production to locally available monosaccharides was observed. Finally, our results demonstrate that A. niger employs different enzymatic tools to adapt its metabolism as it colonizes complex environments.

Electrochemical process for the preparation of nitrogen fertilizers

DOEpatents

Aulich, Ted R.; Olson, Edwin S.; Jiang, Junhua

2013-03-19

The present invention provides methods and apparatus for the preparation of nitrogen fertilizers including ammonium nitrate, urea, urea-ammonium nitrate, and/or ammonia utilizing a source of carbon, a source of nitrogen, and/or a source of hydrogen. Implementing an electrolyte serving as ionic charge carrier, (1) ammonium nitrate is produced via the reduction of a nitrogen source at the cathode and the oxidation of a nitrogen source at the anode; (2) urea or its isomers are produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source; (3) ammonia is produced via the reduction of nitrogen source at the cathode and the oxidation of a hydrogen source at the anode; and (4) urea-ammonium nitrate is produced via the simultaneous cathodic reduction of a carbon source and a nitrogen source, and anodic oxidation of a nitrogen source. The electrolyte can be solid.

Enhanced biomass production through optimization of carbon source and utilization of wastewater as a nutrient source.

PubMed

Gupta, Prabuddha L; Choi, Hee-Jeong; Pawar, Radheshyam R; Jung, Sokhee P; Lee, Seung-Mok

2016-12-15

The study aimed to utilize the domestic wastewater as nutrient feedstock for mixotrophic cultivation of microalgae by evaluating appropriate carbon source. The microalgae Chlorella vulgaris was cultivated in municipal wastewater under various carbon sources (glucose, glycerol, and acetate), followed by optimization of appropriate carbon source concentration to augment the biomass, lipid, and carbohydrate contents. Under optimized conditions, namely of 5 g/L glucose, C. vulgaris showed higher increments of biomass with 1.39 g/L dry cell weight achieving biomass productivity of 0.13 g/L/d. The biomass accumulated 19.29 ± 1.83% total lipid, 41.4 ± 1.46% carbohydrate, and 33.06 ± 1.87% proteins. Moreover, the cultivation of Chlorella sp. in glucose-supplemented wastewater removed 96.9% chemical oxygen demand, 65.3% total nitrogen, and 71.2% total phosphate. The fatty acid methyl ester obtained showed higher amount (61.94%) of saturated fatty acid methyl esters associated with the improved fuel properties. These results suggest that mixotrophic cultivation using glucose offers great potential in the production of renewable biomass, wastewater treatment, and consequent production of high-value microalgal oil. Copyright © 2016 Elsevier Ltd. All rights reserved.

Glucose repression in Saccharomyces cerevisiae.

PubMed

Kayikci, Ömur; Nielsen, Jens

2015-09-01

Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration and gluconeogenesis. This dominant effect of glucose on yeast carbon metabolism is coordinated by several signaling and metabolic interactions that mainly regulate transcriptional activity but are also effective at post-transcriptional and post-translational levels. This review describes effects of glucose repression on yeast carbon metabolism with a focus on roles of the Snf3/Rgt2 glucose-sensing pathway and Snf1 signal transduction in establishment and relief of glucose repression. © FEMS 2015.

Carbon utilization profile of the filamentous fungal species Fusarium fujikuroi, Penicillium decumbens, and Sarocladium strictum isolated from marine coastal environments.

PubMed

Fuentes, Marcelo E; Quiñones, Renato A

Facultative marine filamentous fungi have recently emerged as a functional component in coastal marine systems. However, little is known about their ecological role and functions in biogeochemical cycles. Penicillium decumbens, S. strictum, and F. fujikuroi were isolated from the coastal upwelling zone off south-central Chile. Their carbon profiles were characterized using Biolog FF MicroPlates. These species used a wide range of carbon sources, mainly carbohydrates, but also amino acids, suggesting the use of metabolic routes that include glycolysis/gluconeogenesis. Substrate richness revealed a great capacity for the utilization of nutritional sources, reflected by the following Shannon Indices of utilization of specific substrates: 4.02 for S. strictum, 4.01 for P. decumbes, and 3.91 for F. fujikuroi, which reveals a high physiological capacity for oxidizing different substrates. Significant differences were found between 18 substrates utilized by all three species. Results suggest that filamentous fungi should be considered an integral part of the marine microbial community and included in biogeochemical cycling models of upwelling ecosystems.

Polymorphism of Malassezia furfur.

PubMed

Salkin, I F; Gordon, M A

1977-04-01

Alterations in the morphologic and physiologic characters of 11 isolates of Pityrosporum orbiculare were noted upon prolonged maintenance in pure culture. Successive subculturing of each isolate resulted in its progressive conversion from globose (P. orbiculare) through ovoid to cylindrical (P. ovale) form. Globose forms utilized neither olive oil nor Tween 20 as a sole carbon source, nor KNO3 as a sole source of nitrogen, while ovoid and cylindrical forms utilized both of these carbon sources, and one of four strains of the cylindrical form assimilated KNO3. These results suggest that P. orbiculare and P. ovale are stages in the complex developmental cycle of a single species (Malassezia furfur), but the three names should be preserved until the life cycle is more fully understood.

Biodegradation and utilization of 4-n-nonylphenol by Aspergillus versicolor as a sole carbon and energy source.

PubMed

Krupiński, Mariusz; Janicki, Tomasz; Pałecz, Bartłomiej; Długoński, Jerzy

2014-09-15

4-n-Nonylphenol (4-n-NP) is an environmental pollutant with endocrine-disrupting activities that is formed during the degradation of nonylphenol polyethoxylates, which are widely used as surfactants. Utilization of 4-n-NP by the filamentous fungus Aspergillus versicolor as the sole carbon and energy source was investigated. By means of gas chromatography-mass spectrometry, we showed that in the absence of any carbon source other than 4-n-NP in the medium, A. versicolor completely removed the xenobiotic (100 mg L(-1)) after 3 d of cultivation. Moreover, mass spectrometric analysis of intracellular extracts led to the identification of eight intermediates. The mineralization of the xenobiotic in cultures supplemented with 4-n-NP [ring-(14)C(U)] as a growth substrate was also assessed. After 3 d of incubation, approximately 50% of the initially applied radioactivity was recovered in the form of (14)CO2, proving that this xenobiotic was completely metabolized and utilized by A. versicolor as a carbon source. Based on microscopic analysis, A. versicolor is capable of germinating spores under such conditions. To confirm these observations, a microcalorimetric method was used. The results show that even the highest amount of 4-n-NP initiates heat production in the fungal samples, proving that metabolic processes were affected by the use of 4-n-NP as an energetic substrate. Copyright © 2014 Elsevier B.V. All rights reserved.

[Carbon source metabolic diversity of soil microbial community under different climate types in the area affected by Wenchuan earthquake].

PubMed

Zhang, Guang-Shuai; Lin, Yong-Ming; Ma, Rui-Feng; Deng, Hao-Jun; Du, Kun; Wu, Cheng-Zhen; Hong, Wei

2015-02-01

The MS8.0 Wenchuan earthquake in 2008 led to huge damage to land covers in northwest Sichuan, one of the critical fragile eco-regions in China which can be divided into Semi-arid dry hot climate zone (SDHC) and Subtropical humid monsoon climate zone (SHMC). Using the method of Bilog-ECO-microplate technique, this paper aimed to determine the functional diversity of soil microbial community in the earthquake-affected areas which can be divided into undamaged area (U), recover area (R) and damaged area without recovery (D) under different climate types, in order to provide scientific basis for ecological recovery. The results indicated that the average-well-color-development (AWCD) in undamaged area and recovery area showed SDHC > SHMC, which was contrary to the AWCD in the damaged area without recovery. The AWCD of damaged area without recovery was the lowest in both climate zones. The number of carbon source utilization types of soil microbial in SHMC zone was significantly higher than that in SDHC zone. The carbon source utilization types in both climate zones presented a trend of recover area > undamaged area > damaged area without recovery. The carbon source metabolic diversity characteristic of soil microbial community was significantly different in different climate zones. The diversity index and evenness index both showed a ranking of undamaged area > recover area > damaged area without recovery. In addition, the recovery area had the highest richness index. The soil microbial carbon sources metabolism characteristic was affected by soil nutrient, aboveground vegetation biomass and vegetation coverage to some extent. In conclusion, earthquake and its secondary disasters influenced the carbon source metabolic diversity characteristic of soil microbial community mainly through the change of aboveground vegetation and soil environmental factors.

L-Arogenate is a chemoattractant which can be utilized as the sole source of carbon and nitrogen by Pseudomonas aeruginosa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, R.S.; Song, Jian; Gu, Wei

L-Arogenate is a commonplace amino acid in nature in consideration of its role as a ubiquitous precursor of L-phenylalanine and/or L-tyrosine. However, the questions of whether it serves as a chemoattractant molecule and whether it can serve as a substrate for catabolism have never been studied. We found that Pseudomonas aeruginosa recognizes L-arogenate as a chemoattractant molecule which can be utilized as a source of both carbon and nitrogen. Mutants lacking expression of either cyclohexadienyl dehydratase or phenylalanine hydroxylase exhibited highly reduced growth rates when utilizing L-arogenate as a nitrogen source. Utilization of L-arogenate as a source of either carbonmore » or nitrogen was dependent upon {sub S}{sup 54}, as revealed by the use of an rpoN null mutant. The evidence suggests that catabolism of L-arogenate proceeds via alternative pathways which converge at 4-hydroxyphenylpyruvate. In one pathway, prephenate formed in the periplasm by deamination of L-arogenate is converted to 4-hydroxyphenylpyruvate by cyclohexadienyl dehydrogenase. The second route depends upon the sequential action of periplasmic cyclohexadienyl dehydratase, phenylalanine hydroxylase, and aromatic aminotransferase. 32 refs., 5 figs., 4 tabs.« less

Heterologous production of an energy-conserving carbon monoxide dehydrogenase complex in the hyperthermophile Pyrococcus furiosus

DOE PAGES

Schut, Gerrit J.; Lipscomb, Gina L.; Nguyen, Diep M. N.; ...

2016-01-29

In this study, carbon monoxide (CO) is an important intermediate in anaerobic carbon fixation pathways in acetogenesis and methanogenesis. In addition, some anaerobes can utilize CO as an energy source. In the hyperthermophilic archaeon Thermococcus onnurineus, which grows optimally at 80°C, CO oxidation and energy conservation is accomplished by a respiratory complex encoded by a 16-gene cluster containing a CO dehydrogenase, a membrane-bound [NiFe]-hydrogenase and a Na +/H + antiporter module. This complex oxidizes CO, evolves CO 2 and H 2, and generates a Na+ motive force that is used to conserve energy by a Na+-dependent ATP synthase. Herein wemore » used a bacterial artificial chromosome to insert the 13.2 kb gene cluster encoding the CO-oxidizing respiratory complex of T. onnurineus into the genome of the heterotrophic archaeon, Pyrococcus furiosus, which grows optimally at 100° C. P. furiosus is normally unable to utilize CO, however, the recombinant strain readily oxidized CO and generated H 2 at 80° C. Moreover, CO also served as an energy source and allowed the P. furiosus strain to grow with a limiting concentration of sugar or with peptides as the carbon source. Moreover, CO oxidation by P. furiosus was also coupled to the re-utilization, presumably for biosynthesis, of acetate generated by fermentation. The functional transfer of CO utilization between Thermococcus and Pyrococcus species demonstrated herein is representative of the horizontal gene transfer of an environmentally relevant metabolic capability. The transfer of CO utilizing, hydrogen-producing genetic modules also has applications for biohydrogen production and a CO-based industrial platform for various thermophilic organisms.« less

Metabolome analysis-based design and engineering of a metabolic pathway in Corynebacterium glutamicum to match rates of simultaneous utilization of D-glucose and L-arabinose.

PubMed

Kawaguchi, Hideo; Yoshihara, Kumiko; Hara, Kiyotaka Y; Hasunuma, Tomohisa; Ogino, Chiaki; Kondo, Akihiko

2018-05-17

L-Arabinose is the second most abundant component of hemicellulose in lignocellulosic biomass, next to D-xylose. However, few microorganisms are capable of utilizing pentoses, and catabolic genes and operons enabling bacterial utilization of pentoses are typically subject to carbon catabolite repression by more-preferred carbon sources, such as D-glucose, leading to a preferential utilization of D-glucose over pentoses. In order to simultaneously utilize both D-glucose and L-arabinose at the same rate, a modified metabolic pathway was rationally designed based on metabolome analysis. Corynebacterium glutamicum ATCC 31831 utilized D-glucose and L-arabinose simultaneously at a low concentration (3.6 g/L each) but preferentially utilized D-glucose over L-arabinose at a high concentration (15 g/L each), although L-arabinose and D-glucose were consumed at comparable rates in the absence of the second carbon source. Metabolome analysis revealed that phosphofructokinase and pyruvate kinase were major bottlenecks for D-glucose and L-arabinose metabolism, respectively. Based on the results of metabolome analysis, a metabolic pathway was engineered by overexpressing pyruvate kinase in combination with deletion of araR, which encodes a repressor of L-arabinose uptake and catabolism. The recombinant strain utilized high concentrations of D-glucose and L-arabinose (15 g/L each) at the same consumption rate. During simultaneous utilization of both carbon sources at high concentrations, intracellular levels of phosphoenolpyruvate declined and acetyl-CoA levels increased significantly as compared with the wild-type strain that preferentially utilized D-glucose. These results suggest that overexpression of pyruvate kinase in the araR deletion strain increased the specific consumption rate of L-arabinose and that citrate synthase activity becomes a new bottleneck in the engineered pathway during the simultaneous utilization of D-glucose and L-arabinose. Metabolome analysis identified potential bottlenecks in D-glucose and L-arabinose metabolism and was then applied to the following rational metabolic engineering. Manipulation of only two genes enabled simultaneous utilization of D-glucose and L-arabinose at the same rate in metabolically engineered C. glutamicum. This is the first report of rational metabolic design and engineering for simultaneous hexose and pentose utilization without inactivating the phosphotransferase system.

Improving source identification of Atlanta aerosol using temperature resolved carbon fractions in positive matrix factorization

NASA Astrophysics Data System (ADS)

Kim, Eugene; Hopke, Philip K.; Edgerton, Eric S.

Daily integrated PM 2.5 (particulate matter ⩽2.5 μm in aerodynamic diameter) composition data including eight individual carbon fractions collected at the Jefferson Street monitoring site in Atlanta were analyzed with positive matrix factorization (PMF). Particulate carbon was analyzed using the thermal optical reflectance method that divides carbon into four organic carbon (OC), pyrolized organic carbon (OP), and three elemental carbon (EC) fractions. A total of 529 samples and 28 variables were measured between August 1998 and August 2000. PMF identified 11 sources in this study: sulfate-rich secondary aerosol I (50%), on-road diesel emissions (11%), nitrate-rich secondary aerosol (9%), wood smoke (7%), gasoline vehicle (6%), sulfate-rich secondary aerosol II (6%), metal processing (3%), airborne soil (3%), railroad traffic (3%), cement kiln/carbon-rich (2%), and bus maintenance facility/highway traffic (2%). Differences from previous studies using only the traditional OC and EC data (J. Air Waste Manag. Assoc. 53(2003a)731; Atmos Environ. (2003b)) include four traffic-related combustion sources (gasoline vehicle, on-road diesel, railroad, and bus maintenance facility) containing carbon fractions whose abundances were different between the various sources. This study indicates that the temperature resolved fractional carbon data can be utilized to enhance source apportionment study, especially with respect to the separation of diesel emissions from gasoline vehicle sources. Conditional probability functions using surface wind data and identified source contributions aid the identifications of local point sources.

Biodegradation of Metal-EDTA Complexes by an Enriched Microbial Population

PubMed Central

Thomas, Russell A. P.; Lawlor, Kirsten; Bailey, Mark; Macaskie, Lynne E.

1998-01-01

A mixed culture utilizing EDTA as the sole carbon source was isolated from a mixed inoculum of water from the River Mersey (United Kingdom) and sludge from an industrial effluent treatment plant. Fourteen component organisms were isolated from the culture, including representatives of the genera Methylobacterium, Variovorax, Enterobacter, Aureobacterium, and Bacillus. The mixed culture biodegraded metal-EDTA complexes slowly; the biodegradability was in the order Fe>Cu>Co>Ni>Cd. By incorporation of inorganic phosphate into the medium as a precipitant ligand, heavy metals were removed in parallel to EDTA degradation. The mixed culture also utilized a number of possible EDTA degradation intermediates as carbon sources. PMID:9546167

Pichia pastoris regulates its gene-specific response to different carbon sources at the transcriptional, rather than the translational, level.

PubMed

Prielhofer, Roland; Cartwright, Stephanie P; Graf, Alexandra B; Valli, Minoska; Bill, Roslyn M; Mattanovich, Diethard; Gasser, Brigitte

2015-03-11

The methylotrophic, Crabtree-negative yeast Pichia pastoris is widely used as a heterologous protein production host. Strong inducible promoters derived from methanol utilization genes or constitutive glycolytic promoters are typically used to drive gene expression. Notably, genes involved in methanol utilization are not only repressed by the presence of glucose, but also by glycerol. This unusual regulatory behavior prompted us to study the regulation of carbon substrate utilization in different bioprocess conditions on a genome wide scale. We performed microarray analysis on the total mRNA population as well as mRNA that had been fractionated according to ribosome occupancy. Translationally quiescent mRNAs were defined as being associated with single ribosomes (monosomes) and highly-translated mRNAs with multiple ribosomes (polysomes). We found that despite their lower growth rates, global translation was most active in methanol-grown P. pastoris cells, followed by excess glycerol- or glucose-grown cells. Transcript-specific translational responses were found to be minimal, while extensive transcriptional regulation was observed for cells grown on different carbon sources. Due to their respiratory metabolism, cells grown in excess glucose or glycerol had very similar expression profiles. Genes subject to glucose repression were mainly involved in the metabolism of alternative carbon sources including the control of glycerol uptake and metabolism. Peroxisomal and methanol utilization genes were confirmed to be subject to carbon substrate repression in excess glucose or glycerol, but were found to be strongly de-repressed in limiting glucose-conditions (as are often applied in fed batch cultivations) in addition to induction by methanol. P. pastoris cells grown in excess glycerol or glucose have similar transcript profiles in contrast to S. cerevisiae cells, in which the transcriptional response to these carbon sources is very different. The main response to different growth conditions in P. pastoris is transcriptional; translational regulation was not transcript-specific. The high proportion of mRNAs associated with polysomes in methanol-grown cells is a major finding of this study; it reveals that high productivity during methanol induction is directly linked to the growth condition and not only to promoter strength.

Transporter engineering in biomass utilization by yeast.

PubMed

Hara, Kiyotaka Y; Kobayashi, Jyumpei; Yamada, Ryosuke; Sasaki, Daisuke; Kuriya, Yuki; Hirono-Hara, Yoko; Ishii, Jun; Araki, Michihiro; Kondo, Akihiko

2017-11-01

Biomass resources are attractive carbon sources for bioproduction because of their sustainability. Many studies have been performed using biomass resources to produce sugars as carbon sources for cell factories. Expression of biomass hydrolyzing enzymes in cell factories is an important approach for constructing biomass-utilizing bioprocesses because external addition of these enzymes is expensive. In particular, yeasts have been extensively engineered to be cell factories that directly utilize biomass because of their manageable responses to many genetic engineering tools, such as gene expression, deletion and editing. Biomass utilizing bioprocesses have also been developed using these genetic engineering tools to construct metabolic pathways. However, sugar input and product output from these cells are critical factors for improving bioproduction along with biomass utilization and metabolic pathways. Transporters are key components for efficient input and output activities. In this review, we focus on transporter engineering in yeast to enhance bioproduction from biomass resources. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Highlighting Uncertainty and Recommendations for Improvement of Black Carbon Biomass Fuel-Based Emission Inventories in the Indo-Gangetic Plain Region.

PubMed

Soneja, Sutyajeet I; Tielsch, James M; Khatry, Subarna K; Curriero, Frank C; Breysse, Patrick N

2016-03-01

Black carbon (BC) is a major contributor to hydrological cycle change and glacial retreat within the Indo-Gangetic Plain (IGP) and surrounding region. However, significant variability exists for estimates of BC regional concentration. Existing inventories within the IGP suffer from limited representation of rural sources, reliance on idealized point source estimates (e.g., utilization of emission factors or fuel-use estimates for cooking along with demographic information), and difficulty in distinguishing sources. Inventory development utilizes two approaches, termed top down and bottom up, which rely on various sources including transport models, emission factors, and remote sensing applications. Large discrepancies exist for BC source attribution throughout the IGP depending on the approach utilized. Cooking with biomass fuels, a major contributor to BC production has great source apportionment variability. Areas requiring attention tied to research of cookstove and biomass fuel use that have been recognized to improve emission inventory estimates include emission factors, particulate matter speciation, and better quantification of regional/economic sectors. However, limited attention has been given towards understanding ambient small-scale spatial variation of BC between cooking and non-cooking periods in low-resource environments. Understanding the indoor to outdoor relationship of BC emissions due to cooking at a local level is a top priority to improve emission inventories as many health and climate applications rely upon utilization of accurate emission inventories.

Genes of the N-Methylglutamate Pathway Are Essential for Growth of Methylobacterium extorquens DM4 with Monomethylamine

PubMed Central

Gruffaz, Christelle; Muller, Emilie E. L.; Louhichi-Jelail, Yousra; Nelli, Yella R.; Guichard, Gilles

2014-01-01

Monomethylamine (MMA, CH3NH2) can be used as a carbon and nitrogen source by many methylotrophic bacteria. Methylobacterium extorquens DM4 lacks the MMA dehydrogenase encoded by mau genes, which in M. extorquens AM1 is essential for growth on MMA. Identification and characterization of minitransposon mutants with an MMA-dependent phenotype showed that strain DM4 grows with MMA as the sole source of carbon, energy, and nitrogen by the N-methylglutamate (NMG) pathway. Independent mutations were found in a chromosomal region containing the genes gmaS, mgsABC, and mgdABCD for the three enzymes of the pathway, γ-glutamylmethylamide (GMA) synthetase, NMG synthase, and NMG dehydrogenase, respectively. Reverse transcription-PCR confirmed the operonic structure of the two divergent gene clusters mgsABC-gmaS and mgdABCD and their induction during growth with MMA. The genes mgdABCD and mgsABC were found to be essential for utilization of MMA as a carbon and nitrogen source. The gene gmaS was essential for MMA utilization as a carbon source, but residual growth of mutant DM4gmaS growing with succinate and MMA as a nitrogen source was observed. Plasmid copies of gmaS and the gmaS homolog METDI4690, which encodes a protein 39% identical to GMA synthetase, fully restored the ability of mutants DM4gmaS and DM4gmaSΔmetdi4690 to use MMA as a carbon and nitrogen source. Similarly, chemically synthesized GMA, the product of GMA synthetase, could be used as a nitrogen source for growth in the wild-type strain, as well as in DM4gmaS and DM4gmaSΔmetdi4690 mutants. The NADH:ubiquinone oxidoreductase respiratory complex component NuoG was also found to be essential for growth with MMA as a carbon source. PMID:24682302

Molecular characterization and analysis of the acrB gene of Aspergillus nidulans: a gene identified by genetic interaction as a component of the regulatory network that includes the CreB deubiquitination enzyme.

PubMed Central

Boase, Natasha A; Lockington, Robin A; Adams, Julian R J; Rodbourn, Louise; Kelly, Joan M

2003-01-01

Mutations in the acrB gene, which were originally selected through their resistance to acriflavine, also result in reduced growth on a range of sole carbon sources, including fructose, cellobiose, raffinose, and starch, and reduced utilization of omega-amino acids, including GABA and beta-alanine, as sole carbon and nitrogen sources. The acrB2 mutation suppresses the phenotypic effects of mutations in the creB gene that encodes a regulatory deubiquitinating enzyme, and in the creC gene that encodes a WD40-repeat-containing protein. Thus AcrB interacts with a regulatory network controlling carbon source utilization that involves ubiquitination and deubiquitination. The acrB gene was cloned and physically analyzed, and it encodes a novel protein that contains three putative transmembrane domains and a coiled-coil region. AcrB may play a role in the ubiquitination aspect of this regulatory network. PMID:12750323

Radiocarbon Analysis to Calculate New End-Member Values for Biomass Burning Source Samples Specific to the Bay Area

NASA Astrophysics Data System (ADS)

Yoon, S.; Kirchstetter, T.; Fairley, D.; Sheesley, R. J.; Tang, X.

2017-12-01

Elemental carbon (EC), also known as black carbon or soot, is an important particulate air pollutant that contributes to climate forcing through absorption of solar radiation and to adverse human health impacts through inhalation. Both fossil fuel combustion and biomass burning, via residential firewood burning, agricultural burning, wild fires, and controlled burns, are significant sources of EC. Our ability to successfully control ambient EC concentrations requires understanding the contribution of these different emission sources. Radiocarbon (14C) analysis has been increasingly used as an apportionment tool to distinguish between EC from fossil fuel and biomass combustion sources. However, there are uncertainties associated with this method including: 1) uncertainty associated with the isolation of EC to be used for radiocarbon analysis (e.g., inclusion of organic carbon, blank contamination, recovery of EC, etc.) 2) uncertainty associated with the radiocarbon signature of the end member. The objective of this research project is to utilize laboratory experiments to evaluate some of these uncertainties, particularly for EC sources that significantly impact the San Francisco Bay Area. Source samples of EC only and a mix of EC and organic carbon (OC) were produced for this study to represent known emission sources and to approximate the mixing of EC and OC that would be present in the atmosphere. These samples include a combination of methane flame soot, various wood smoke samples (i.e. cedar, oak, sugar pine, pine at various ages, etc.), meat cooking, and smoldering cellulose smoke. EC fractions were isolated using a Sunset Laboratory's thermal optical transmittance carbon analyzer. For 14C analysis, samples were sent to Woods Hole Oceanographic Institution for isotope analysis using an accelerated mass spectrometry. End member values and uncertainties for the EC isolation utilizing this method will be reported.

Incineration of biomass and utilization of product gas as a CO2 source for crop production in closed systems: gas quality and phytotoxicity.

PubMed

Bubenheim, D L; Patterson, M; Wignarajah, K; Flynn, M

1997-01-01

This study addressed the recycle of carbon from inedible biomass to CO2 for utilization in crop production. Earlier work identified incineration as an attractive approach to resource recovery from solid wastes because the products are well segregated. Given the effective separation of carbon into the gaseous product stream from the incinerator in the form of CO2 we captured the gaseous stream produced during incineration of wheat inedible biomass and utilized it as the CO2 source for crop production. Injection rate was based on maintenance of CO2 concentration in the growing environment. The crop grown in the closed system was lettuce. Carbon was primarily in the form of CO2 in the incinerator product gas with less than 8% of carbon compounds appearing as CO. Nitrogen oxides and organic compounds such as toluene, xylene, and benzene were present in the product gas at lower concentrations (< 4 micromol mol-1); sulfur containing compounds were below the detection limits. Direct utilization of the gaseous product of the incinerator as the CO2 source was toxic to lettuce grown in a closed chamber. Net photosynthetic rates of the crop was suppressed more than 50% and visual injury symptoms were visible within 3 days of the introduction of the incinerator gas. Even the removal of the incinerator gas alter two days of crop exposure and replacement with pure CO2 did not eliminate the toxic effects. Both organic and inorganic components of the incinerator gas are candidates for the toxin.

Incineration of biomass and utilization of product gas as a CO2 source for crop production in closed systems: gas quality and phytotoxicity

NASA Astrophysics Data System (ADS)

1997-01-01

This study addressed the recycle of carbon from inedible biomass to CO2 for utilization in crop production. Earlier work identified incineration as an attractive approach to resource recovery from solid wastes because the products are well segregated. Given the effective separation of carbon into the gaseous product stream from the incinerator in the form of CO2 we captured the gaseous stream produced during incineration of wheat inedible biomass and utilized it as the CO2 source for crop production. Injection rate was based on maintenance of CO2 concentration in the growing environment. The crop grown in the closed system was lettuce. Carbon was primarily in the form of CO2 in the incinerator product gas with less than 8% of carbon compounds appearing as CO. Nitrogen oxides and organic compounds such as toluene, xylene, and benzene were present in the product gas at lower concentrations (<4 μmol mol-1) sulfur containing compounds were below the detection limits. Direct utilization of the gaseous product of the incinerator as the CO2 source was toxic to lettuce grown in a closed chamber. Net photosynthetic rates of the crop was suppressed more than 50% and visual injury symptoms were visible within 3 days of the introduction of the incinerator gas. Even the removal of the incinerator gas after two days of crop exposure and replacement with pure CO2 did not eliminate the toxic effects. Both organic and inorganic components of the incinerator gas are candidates for the toxin.

Incineration of biomass and utilization of product gas as a CO_2 source for crop production in closed systems: gas quality and phytotoxicity

NASA Astrophysics Data System (ADS)

Bubenheim, D. L.; Patterson, M.; Wignarajah, K.; Flynn, M.

1997-01-01

This study addressed the recycle of carbon from inedible biomass to CO_2 for utilization in crop production. Earlier work identified incineration as an attractive approach to resource recovery from solid wastes because the products are well segregated. Given the effective separation of carbon into the gaseous product stream from the incinerator in the form of CO_2 we captured the gaseous stream produced during incineration of wheat inedible biomass and utilized it as the CO_2 source for crop production. Injection rate was based on maintenance of CO_2 concentration in the growing environment. The crop grown in the closed system was lettuce. Carbon was primarily in the form of CO_2 in the incinerator product gas with less than 8% of carbon compounds appearing as CO. Nitrogen oxides and organic compounds such as toluene, xylene, and benzene were present in the product gas at lower concentrations (<4 mumol mol^-1) sulfur containing compounds were below the detection limits. Direct utilization of the gaseous product of the incinerator as the CO_2 source was toxic to lettuce grown in a closed chamber. Net photosynthetic rates of the crop was suppressed more than 50% and visual injury symptoms were visible within 3 days of the introduction of the incinerator gas. Even the removal of the incinerator gas after two days of crop exposure and replacement with pure CO_2 did not eliminate the toxic effects. Both organic and inorganic components of the incinerator gas are candidates for the toxin.

Metabolic engineering of Pseudomonas putida for the utilization of parathion as a carbon and energy source.

PubMed

Walker, Andy W; Keasling, Jay D

2002-06-30

Pseudomonas putida KT2442 was engineered to use the organophosphate pesticide parathion, a compound similar to other organophosphate pesticides and chemical warfare agents, as a source of carbon and energy. The initial step in the engineered degradation pathway was parathion hydrolysis by organophosphate hydrolase (OPH) to p-nitrophenol (PNP) and diethyl thiophosphate, compounds that cannot be metabolized by P. putida KT2442. The gene encoding the native OPH (opd), with and without the secretory leader sequence, was cloned into broad-host-range plasmids under the control of tac and taclac promoters. Expression of opd from the tac promoter resulted in high OPH activity, whereas expression from the taclac promoter resulted in low activity. A plasmid-harboring operons encoding enzymes for p-nitrophenol transformation to beta-ketoadipate was transformed into P. putida allowing the organism to use 0.5 mM PNP as a carbon and energy source. Transformation of P. putida with the plasmids harboring opd and the PNP operons allowed the organism to utilize 0.8 mM parathion as a source of carbon and energy. Degradation studies showed that parathion formed a separate dense, non-aqueous phase liquid phase but was still bioavailable. Copyright 2002 Wiley Periodicals, Inc.

Investigations of potential microbial methanogenic and carbon monoxide utilization pathways in ultra-basic reducing springs associated with present-day continental serpentinization: the Tablelands, NL, CAN

PubMed Central

Morrill, Penny L.; Brazelton, William J.; Kohl, Lukas; Rietze, Amanda; Miles, Sarah M.; Kavanagh, Heidi; Schrenk, Matthew O.; Ziegler, Susan E.; Lang, Susan Q.

2014-01-01

Ultra-basic reducing springs at continental sites of serpentinization act as portals into the biogeochemistry of a subsurface environment with H2 and CH4 present. Very little, however, is known about the carbon substrate utilization, energy sources, and metabolic pathways of the microorganisms that live in this ultra-basic environment. The potential for microbial methanogenesis with bicarbonate, formate, acetate, and propionate precursors and carbon monoxide (CO) utilization pathways were tested in laboratory experiments by adding substrates to water and sediment from the Tablelands, NL, CAD, a site of present-day continental serpentinization. Microbial methanogenesis was not observed after bicarbonate, formate, acetate, or propionate addition. CO was consumed in the live experiments but not in the killed controls and the residual CO in the live experiments became enriched in 13C. The average isotopic enrichment factor resulting from this microbial utilization of CO was estimated to be 11.2 ± 0.2‰. Phospholipid fatty acid concentrations and δ13C values suggest limited incorporation of carbon from CO into microbial lipids. This indicates that in our experiments, CO was used primarily as an energy source, but not for biomass growth. Environmental DNA sequencing of spring fluids collected at the same time as the addition experiments yielded a large proportion of Hydrogenophaga-related sequences, which is consistent with previous metagenomic data indicating the potential for these taxa to utilize CO. PMID:25431571

Investigations of potential microbial methanogenic and carbon monoxide utilization pathways in ultra-basic reducing springs associated with present-day continental serpentinization: the Tablelands, NL, CAN.

PubMed

Morrill, Penny L; Brazelton, William J; Kohl, Lukas; Rietze, Amanda; Miles, Sarah M; Kavanagh, Heidi; Schrenk, Matthew O; Ziegler, Susan E; Lang, Susan Q

2014-01-01

Ultra-basic reducing springs at continental sites of serpentinization act as portals into the biogeochemistry of a subsurface environment with H2 and CH4 present. Very little, however, is known about the carbon substrate utilization, energy sources, and metabolic pathways of the microorganisms that live in this ultra-basic environment. The potential for microbial methanogenesis with bicarbonate, formate, acetate, and propionate precursors and carbon monoxide (CO) utilization pathways were tested in laboratory experiments by adding substrates to water and sediment from the Tablelands, NL, CAD, a site of present-day continental serpentinization. Microbial methanogenesis was not observed after bicarbonate, formate, acetate, or propionate addition. CO was consumed in the live experiments but not in the killed controls and the residual CO in the live experiments became enriched in (13)C. The average isotopic enrichment factor resulting from this microbial utilization of CO was estimated to be 11.2 ± 0.2‰. Phospholipid fatty acid concentrations and δ(13)C values suggest limited incorporation of carbon from CO into microbial lipids. This indicates that in our experiments, CO was used primarily as an energy source, but not for biomass growth. Environmental DNA sequencing of spring fluids collected at the same time as the addition experiments yielded a large proportion of Hydrogenophaga-related sequences, which is consistent with previous metagenomic data indicating the potential for these taxa to utilize CO.

Calcifying Cyanobacteria - The potential of biomineralization for Carbon Capture and Storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jansson, Christer G; Northen, Trent

2010-03-26

Employment of cyanobacteria in biomineralization of carbon dioxide by calcium carbonate precipitation offers novel and self-sustaining strategies for point-source carbon capture and sequestration. Although details of this process remain to be elucidated, a carbon-concentrating mechanism, and chemical reactions in exopolysaccharide or proteinaceous surface layers are assumed to be of crucial importance. Cyanobacteria can utilize solar energy through photosynthesis to convert carbon dioxide to recalcitrant calcium carbonate. Calcium can be derived from sources such as gypsum or industrial brine. A better understanding of the biochemical and genetic mechanisms that carry out and regulate cynaobacterial biomineralization should put us in a positionmore » where we can further optimize these steps by exploiting the powerful techniques of genetic engineering, directed evolution, and biomimetics.« less

Growth of Azotobacter chroococcum in chemically defined media containing p-hydroxybenzoic acid and protocatechuic acid.

PubMed

Juarez, B; Martinez-Toledo, M V; Gonzalez-Lopez, J

2005-06-01

Growth and utilization of different phenolic acids present in olive mill wastewater (OMW) by Azotobacter chroococcum were studied in chemically defined media. Growth and utilization of phenolic acids were only detected when the microorganism was cultured on p-hydroxybenzoic acid at concentration from 0.01% to 0.5% (w/v) and protocatechuic acid at concentration from 0.01% to 0.3% (w/v) as sole carbon sources suggesting that only these phenolic compounds could be utilized as a carbon source by A. chroococcum. Moreover when culture media were added with a mixture of 0.3% of protocatechuic acid and 0.3% p-hydroxybenzoic acid, the microorganism degradated in first place protocatechuic acid and once the culture medium was depleted of this compound, the degradation of p-hydroxybenzoic acid commenced very fast.

Preliminary studies on the evolution of carbon assimilation abilities within Mucorales.

PubMed

Pawłowska, Julia; Aleksandrzak-Piekarczyk, Tamara; Banach, Agnieszka; Kiersztyn, Bartosz; Muszewska, Anna; Serewa, Lidia; Szatraj, Katarzyna; Wrzosek, Marta

2016-05-01

Representatives of Mucorales belong to one of the oldest lineages of terrestrial fungi. Although carbon is of fundamental importance for fungal growth and functioning, relatively little is known about enzymatic capacities of Mucorales. The evolutionary history and the variability of the capacity to metabolize different carbon sources among representatives of the order Mucorales was studied using Phenotypic Microarray Plates. The ability of 26 strains belonging to 23 nonpathogenic species of Mucorales to use 95 different carbon sources was tested. Intraspecies variability of carbon assimilation profiles was lower than interspecies variation for some selected strains. Although similarities between the phylogenetic tree and the dendrogram created from carbon source utilization data were observed, the ability of the various strains to use the analyzed substrates did not show a clear correlation with the evolutionary history of the group. Instead, carbon assimilation profiles are probably shaped by environmental conditions. Copyright © 2016 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Statistical aspects of carbon fiber risk assessment modeling. [fire accidents involving aircraft

NASA Technical Reports Server (NTRS)

Gross, D.; Miller, D. R.; Soland, R. M.

1980-01-01

The probabilistic and statistical aspects of the carbon fiber risk assessment modeling of fire accidents involving commercial aircraft are examined. Three major sources of uncertainty in the modeling effort are identified. These are: (1) imprecise knowledge in establishing the model; (2) parameter estimation; and (3)Monte Carlo sampling error. All three sources of uncertainty are treated and statistical procedures are utilized and/or developed to control them wherever possible.

The carbon storage regulator (Csr) system exerts a nutrient-specific control over central metabolism in Escherichia coli strain Nissle 1917.

PubMed

Revelles, Olga; Millard, Pierre; Nougayrède, Jean-Philippe; Dobrindt, Ulrich; Oswald, Eric; Létisse, Fabien; Portais, Jean-Charles

2013-01-01

The role of the post-transcriptional carbon storage regulator (Csr) system in nutrient utilization and in the control of the central metabolism in E. coli reference commensal strain Nissle 1917 was investigated. Analysis of the growth capabilities of mutants altered for various components of the Csr system (csrA51, csrB, csrC and csrD mutations) showed that only the protein CsrA - the key component of the system - exerts a marked role in carbon nutrition. Attenuation of CsrA activity in the csrA51 mutant affects the growth efficiency on a broad range of physiologically relevant carbon sources, including compounds utilized by the Entner-Doudoroff (ED) pathway. Detailed investigations of the metabolomes and fluxomes of mutants and wild-type cells grown on carbon sources representative of glycolysis and of the ED pathway (glucose and gluconate, respectively), revealed significant re-adjusting of central carbon metabolism for both compounds in the csrA51 mutant. However, the metabolic re-adjusting observed on gluconate was strikingly different from that observed on glucose, indicating a nutrient-specific control of metabolism by the Csr system.

The Carbon Storage Regulator (Csr) System Exerts a Nutrient-Specific Control over Central Metabolism in Escherichia coli Strain Nissle 1917

PubMed Central

Nougayrède, Jean-Philippe; Dobrindt, Ulrich; Oswald, Eric; Létisse, Fabien; Portais, Jean-Charles

2013-01-01

The role of the post-transcriptional carbon storage regulator (Csr) system in nutrient utilization and in the control of the central metabolism in E. coli reference commensal strain Nissle 1917 was investigated. Analysis of the growth capabilities of mutants altered for various components of the Csr system (csrA51, csrB, csrC and csrD mutations) showed that only the protein CsrA - the key component of the system - exerts a marked role in carbon nutrition. Attenuation of CsrA activity in the csrA51 mutant affects the growth efficiency on a broad range of physiologically relevant carbon sources, including compounds utilized by the Entner-Doudoroff (ED) pathway. Detailed investigations of the metabolomes and fluxomes of mutants and wild-type cells grown on carbon sources representative of glycolysis and of the ED pathway (glucose and gluconate, respectively), revealed significant re-adjusting of central carbon metabolism for both compounds in the csrA51 mutant. However, the metabolic re-adjusting observed on gluconate was strikingly different from that observed on glucose, indicating a nutrient-specific control of metabolism by the Csr system. PMID:23840455

Functional Stability Of A Mixed Microbial Consortia Producing PHA From Waste Carbon Sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

David N. Thompson; Erik R. Coats; William A. Smith

2006-04-01

Polyhydroxyalkanoates (PHAs), naturally-occurring biological polyesters that are microbially synthesized from a myriad of carbon sources, can be utilized as biodegradable substitutes for petroleum-derived thermoplastics. However, current PHA commercialization schemes are limited by high feedstock costs, the requirement for aseptic reactors, and high separation and purification costs. Bacteria indigenous to municipal waste streams can accumulate large quantities of PHA under environmentally controlled conditions; hence, a potentially more environmentally-effective method of production would utilize these consortia to produce PHAs from inexpensive waste carbon sources. In this study, PHA production was accomplished in sequencing batch bioreactors utilizing mixed microbial consortia from municipal activatedmore » sludge as inoculum, in cultures grown on real wastewaters. PHA production averaged 85%, 53%, and 10% of the cell dry weight from methanol-enriched pulp-and-paper mill foul condensate, fermented municipal primary solids, and biodiesel wastewater, respectively. The PHA-producing microbial consortia were examined to explore the microbial community changes that occurred during reactor operations, employing denaturing gradient gel electrophoresis (DGGE) of 16S-rDNA from PCR-amplified DNA extracts. Distinctly different communities were observed both between and within wastewaters following enrichment. More importantly, stable functions were maintained despite the differing and contrasting microbial populations.« less

Activated sludge is a potential source for production of biodegradable plastics from wastewater.

PubMed

Khardenavis, A; Guha, P K; Kumar, M S; Mudliar, S N; Chakrabarti, T

2005-05-01

Increased utilization of synthetic plastics caused severe environmental pollution due to their non-biodegradable nature. In the search for environmentally friendly materials to substitute for conventional plastics, different biodegradable plastics have been developed by microbial fermentations. However, limitations of these materials still exist due to high cost. This study aims at minimization of cost for the production of biodegradable plastics P(3HB) and minimization of environmental pollution. The waste biological sludge generated at wastewater treatment plants is used for the production of P(3HB) and wastewater is used as carbon source. Activated sludge was induced by controlling the carbon: nitrogen ratio to accumulate storage polymer. Initially polymer accumulation was studied by using different carbon and nitrogen sources. Maximum accumulation of polymer was observed with carbon source acetic acid and diammonium hydrogen phosphate (DAHP) as nitrogen source. Further studies were carried out to optimize the carbon: nitrogen ratios using acetic acid and DAHP. A maximum of 65.84% (w/w) P(3HB) production was obtained at C/N ratio of 50 within 96 hours of incubation.

A time resolved metabolomics study: the influence of different carbon sources during growth and starvation of Bacillus subtilis.

PubMed

Meyer, Hanna; Weidmann, Hendrikje; Mäder, Ulrike; Hecker, Michael; Völker, Uwe; Lalk, Michael

2014-07-01

In its natural environment, the soil, the Gram-positive model bacterium Bacillus subtilis frequently encounters nutrient limitation and other stress factors. Efficient adaptation mechanisms are necessary to cope with this wide range of environmental challenges. The ability to utilize diverse carbon sources represents a key adaptation process that allows B. subtilis to thrive in its natural habitat. To gain a comprehensive insight into the metabolism of B. subtilis, global metabolite analyses were performed during growth with glucose alone or glucose with either malate, fumarate or citrate as carbon/energy sources. Furthermore, to achieve a comprehensive coverage of a wide range of chemically different metabolites, complementary GC-MS, LC-MS and (1)H-NMR analyses were applied. This study reveals that the availability of different carbon sources results in different extracellular metabolite profiles whereas a regulated intracellular metabolite equilibrium was observed. In addition, the typical energy-starvation induced activation of the general stress sigma factor σ(B) was only observed upon entry into the stationary phase with glucose or glucose and malate as carbon sources.

Physiological and biogeochemical traits of bleaching and recovery in the mounding species of coral Porites lobata: implications for resilience in mounding corals.

PubMed

Levas, Stephen J; Grottoli, Andréa G; Hughes, Adam; Osburn, Christopher L; Matsui, Yohei

2013-01-01

Mounding corals survive bleaching events in greater numbers than branching corals. However, no study to date has determined the underlying physiological and biogeochemical trait(s) that are responsible for mounding coral holobiont resilience to bleaching. Furthermore, the potential of dissolved organic carbon (DOC) as a source of fixed carbon to bleached corals has never been determined. Here, Porites lobata corals were experimentally bleached for 23 days and then allowed to recover for 0, 1, 5, and 11 months. At each recovery interval a suite of analyses were performed to assess their recovery (photosynthesis, respiration, chlorophyll a, energy reserves, tissue biomass, calcification, δ(13)C of the skeletal, δ(13)C, and δ(15)N of the animal host and endosymbiont fractions). Furthermore, at 0 months of recovery, the assimilation of photosynthetically acquired and zooplankton-feeding acquired carbon into the animal host, endosymbiont, skeleton, and coral-mediated DOC were measured via (13)C-pulse-chase labeling. During the first month of recovery, energy reserves and tissue biomass in bleached corals were maintained despite reductions in chlorophyll a, photosynthesis, and the assimilation of photosynthetically fixed carbon. At the same time, P. lobata corals catabolized carbon acquired from zooplankton and seemed to take up DOC as a source of fixed carbon. All variables that were negatively affected by bleaching recovered within 5 to 11 months. Thus, bleaching resilience in the mounding coral P. lobata is driven by its ability to actively catabolize zooplankton-acquired carbon and seemingly utilize DOC as a significant fixed carbon source, facilitating the maintenance of energy reserves and tissue biomass. With the frequency and intensity of bleaching events expected to increase over the next century, coral diversity on future reefs may favor not only mounding morphologies but species like P. lobata, which have the ability to utilize heterotrophic sources of fixed carbon that minimize the impact of bleaching and promote fast recovery.

Physiological and Biogeochemical Traits of Bleaching and Recovery in the Mounding Species of Coral Porites lobata: Implications for Resilience in Mounding Corals

PubMed Central

Levas, Stephen J.; Grottoli, Andréa G.; Hughes, Adam; Osburn, Christopher L.; Matsui, Yohei

2013-01-01

Mounding corals survive bleaching events in greater numbers than branching corals. However, no study to date has determined the underlying physiological and biogeochemical trait(s) that are responsible for mounding coral holobiont resilience to bleaching. Furthermore, the potential of dissolved organic carbon (DOC) as a source of fixed carbon to bleached corals has never been determined. Here, Porites lobata corals were experimentally bleached for 23 days and then allowed to recover for 0, 1, 5, and 11 months. At each recovery interval a suite of analyses were performed to assess their recovery (photosynthesis, respiration, chlorophyll a, energy reserves, tissue biomass, calcification, δ13C of the skeletal, δ13C, and δ15N of the animal host and endosymbiont fractions). Furthermore, at 0 months of recovery, the assimilation of photosynthetically acquired and zooplankton-feeding acquired carbon into the animal host, endosymbiont, skeleton, and coral-mediated DOC were measured via 13C-pulse-chase labeling. During the first month of recovery, energy reserves and tissue biomass in bleached corals were maintained despite reductions in chlorophyll a, photosynthesis, and the assimilation of photosynthetically fixed carbon. At the same time, P. lobata corals catabolized carbon acquired from zooplankton and seemed to take up DOC as a source of fixed carbon. All variables that were negatively affected by bleaching recovered within 5 to 11 months. Thus, bleaching resilience in the mounding coral P. lobata is driven by its ability to actively catabolize zooplankton-acquired carbon and seemingly utilize DOC as a significant fixed carbon source, facilitating the maintenance of energy reserves and tissue biomass. With the frequency and intensity of bleaching events expected to increase over the next century, coral diversity on future reefs may favor not only mounding morphologies but species like P. lobata, which have the ability to utilize heterotrophic sources of fixed carbon that minimize the impact of bleaching and promote fast recovery. PMID:23658817

Microbial degradation of phosmet on blueberry fruit and in aqueous systems by indigenous bacterial flora on lowbush blueberries (Vaccinium angustifolium).

PubMed

Crowe, K M; Bushway, A A; Bushway, R J; Davis-Dentici, K

2007-10-01

Phosmet-adapted bacteria isolated from lowbush blueberries (Vaccinium angustifolium) were evaluated for their ability to degrade phosmet on blueberry fruit and in minimal salt solutions. Microbial metabolism of phosmet by isolates of Enterobacter agglomerans and Pseudomonas fluorescens resulted in significant reductions (P < 0.05; 33.8%) in phosmet residues on blueberry fruit. Degradation was accompanied by microbial proliferation of phosmet-adapted bacteria. Preferential utilization of phosmet as a carbon source was investigated in minimal salt solutions inoculated with either E. agglomerans or P. fluorescens and supplemented with phosmet or phosmet and glucose. Microbial degradation concurrent with the proliferation of P. fluorescens was similar in both liquid systems, indicative of preferential utilization of phosmet as an energy substrate. E. agglomerans exhibited the ability to degrade phosmet as a carbon source, yet in the presence of added glucose, phosmet degradation occurred within the 1st 24 h only followed by total population mortality resulting in no appreciable degradation. Characteristic utilization of glucose by this isolate suggests a possible switch in carbon substrate utilization away from phosmet, which resulted in toxicity from the remaining phosmet. Overall, microbial metabolism of phosmet as an energy source resulted in significant degradation of residues on blueberries and in minimal salt solutions. Thus, the role of adapted strains of E. agglomerans and P. fluorescens in degrading phosmet on blueberries represents an extensive plant-microorganism relationship, which is essential to determination of phosmet persistence under pre- and postharvest conditions.

Engineered Enterobacter aerogenes for efficient utilization of sugarcane molasses in 2,3-butanediol production.

PubMed

Jung, Moo-Young; Park, Bu-Soo; Lee, Jinwon; Oh, Min-Kyu

2013-07-01

Sugarcane molasses is considered to be a good carbon source for biorefinery due to its high sugar content and low price. Sucrose occupies more than half of the sugar in the molasses. Enterobacter aerogenes is a good host strain for 2,3-butanediol production, but its utilization of sucrose is not very efficient. To improve sucrose utilization in E. aerogenes, a sucrose regulator (ScrR) was disrupted from the genomic DNA. The deletion mutation increased the sucrose consumption rate significantly when sucrose or sugarcane molasses was used as a carbon source. The 2,3-butanediol production from sugarcane molasses by the mutant was enhanced by 60% in batch fermentation compared to that by the wild type strain. In fed-batch fermentation, 98.69 g/L of 2,3-butanediol production was achieved at 36 h. Copyright © 2013 Elsevier Ltd. All rights reserved.

Formate Metabolism in Shewanella oneidensis Generates Proton Motive Force and Prevents Growth without an Electron Acceptor.

PubMed

Kane, Aunica L; Brutinel, Evan D; Joo, Heena; Maysonet, Rebecca; VanDrisse, Chelsey M; Kotloski, Nicholas J; Gralnick, Jeffrey A

2016-04-01

Shewanella oneidensis strain MR-1 is a facultative anaerobe that thrives in redox-stratified environments due to its ability to utilize a wide array of terminal electron acceptors. Conversely, the electron donors utilized by S. oneidensis are more limited and include products of primary fermentation such as lactate, pyruvate, formate, and hydrogen. Lactate, pyruvate, and hydrogen metabolisms inS. oneidensis have been described previously, but little is known about the role of formate oxidation in the ecophysiology of these bacteria. Formate is produced by S. oneidensis through pyruvate formate lyase during anaerobic growth on carbon sources that enter metabolism at or above the level of pyruvate, and the genome contains three gene clusters predicted to encode three complete formate dehydrogenase complexes. To determine the contribution of each complex to formate metabolism, strains lacking one, two, or all three annotated formate dehydrogenase gene clusters were generated and examined for growth rates and yields on a variety of carbon sources. Here, we report that formate oxidation contributes to both the growth rate and yield of S. oneidensis through the generation of proton motive force. Exogenous formate also greatly accelerated growth on N-acetylglucosamine, a carbon source normally utilized very slowly by S. oneidensis under anaerobic conditions. Surprisingly, deletion of all three formate dehydrogenase gene clusters enabled growth of S. oneidensis using pyruvate in the absence of a terminal electron acceptor, a mode of growth never before observed in these bacteria. Our results demonstrate that formate oxidation is a fundamental strategy under anaerobic conditions for energy conservation inS. oneidensis. Shewanella species have garnered interest in biotechnology applications for their ability to respire extracellular terminal electron acceptors, such as insoluble iron oxides and electrodes. While much effort has gone into studying the proteins for extracellular electron transport, how electrons generated through the oxidation of organic carbon sources enter this pathway remains understudied. Here, we quantify the role of formate oxidation in the anaerobic physiology of Shewanella oneidensis Formate oxidation contributes to both the growth rate and yield on a variety of carbon sources through the generation of proton motive force. Advances in our understanding of the anaerobic metabolism of S. oneidensis are important for our ability to utilize and engineer this organism for applications in bioenergy, biocatalysis, and bioremediation. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Formate Metabolism in Shewanella oneidensis Generates Proton Motive Force and Prevents Growth without an Electron Acceptor

PubMed Central

Kane, Aunica L.; Brutinel, Evan D.; Joo, Heena; Maysonet, Rebecca; VanDrisse, Chelsey M.; Kotloski, Nicholas J.

2016-01-01

ABSTRACT Shewanella oneidensis strain MR-1 is a facultative anaerobe that thrives in redox-stratified environments due to its ability to utilize a wide array of terminal electron acceptors. Conversely, the electron donors utilized by S. oneidensis are more limited and include products of primary fermentation such as lactate, pyruvate, formate, and hydrogen. Lactate, pyruvate, and hydrogen metabolisms in S. oneidensis have been described previously, but little is known about the role of formate oxidation in the ecophysiology of these bacteria. Formate is produced by S. oneidensis through pyruvate formate lyase during anaerobic growth on carbon sources that enter metabolism at or above the level of pyruvate, and the genome contains three gene clusters predicted to encode three complete formate dehydrogenase complexes. To determine the contribution of each complex to formate metabolism, strains lacking one, two, or all three annotated formate dehydrogenase gene clusters were generated and examined for growth rates and yields on a variety of carbon sources. Here, we report that formate oxidation contributes to both the growth rate and yield of S. oneidensis through the generation of proton motive force. Exogenous formate also greatly accelerated growth on N-acetylglucosamine, a carbon source normally utilized very slowly by S. oneidensis under anaerobic conditions. Surprisingly, deletion of all three formate dehydrogenase gene clusters enabled growth of S. oneidensis using pyruvate in the absence of a terminal electron acceptor, a mode of growth never before observed in these bacteria. Our results demonstrate that formate oxidation is a fundamental strategy under anaerobic conditions for energy conservation in S. oneidensis. IMPORTANCE Shewanella species have garnered interest in biotechnology applications for their ability to respire extracellular terminal electron acceptors, such as insoluble iron oxides and electrodes. While much effort has gone into studying the proteins for extracellular electron transport, how electrons generated through the oxidation of organic carbon sources enter this pathway remains understudied. Here, we quantify the role of formate oxidation in the anaerobic physiology of Shewanella oneidensis. Formate oxidation contributes to both the growth rate and yield on a variety of carbon sources through the generation of proton motive force. Advances in our understanding of the anaerobic metabolism of S. oneidensis are important for our ability to utilize and engineer this organism for applications in bioenergy, biocatalysis, and bioremediation. PMID:26883823

Development of a stationary carbon emission inventory for Shanghai using pollution source census data

NASA Astrophysics Data System (ADS)

Li, Xianzhe; Jiang, Ping; Zhang, Yan; Ma, Weichun

2016-12-01

This study utilizes 521,631 activity data points from the 2007 Shanghai Pollution Source Census to compile a stationary carbon emission inventory for Shanghai. The inventory generated from our dataset shows that a large portion of Shanghai's total energy use consists of coal-oriented energy consumption. The electricity and heat production industries, iron and steel mills, and the petroleum refining industry are the main carbon emitters. In addition, most of these industries are located in Baoshan District, which is Shanghai's largest contributor of carbon emissions. Policy makers can use the enterpriselevel carbon emission inventory and the method designed in this study to construct sound carbon emission reduction policies. The carbon trading scheme to be established in Shanghai based on the developed carbon inventory is also introduced in this paper with the aim of promoting the monitoring, reporting and verification of carbon trading. Moreover, we believe that it might be useful to consider the participation of industries, such as those for food processing, beverage, and tobacco, in Shanghai's carbon trading scheme. Based on the results contained herein, we recommend establishing a comprehensive carbon emission inventory by inputting data from the pollution source census used in this study.

Efficient Utilization of Waste Carbon Source for Advanced Nitrogen Removal of Landfill Leachate

PubMed Central

Yin, Wenjun; Tan, Fengxun

2017-01-01

A modified single sequencing batch reactor (SBR) was developed to remove the nitrogen of the real landfill leachate in this study. To take the full advantage of the SBR, stir phase was added before and after aeration, respectively. The new mechanism in this experiment could improve the removal of nitrogen efficiently by the utilization of carbon source in the raw leachate. This experiment adopts the SBR process to dispose of the real leachate, in which the COD and ammonia nitrogen concentrations were about 3800 mg/L and 1000 mg/L, respectively. Results showed that the removal rates of COD and total nitrogen were above 85% and 95%, respectively, and the effluent COD and total nitrogen were less than 500 mg/L and 40 mg/L under the condition of not adding any carbon source. Also, the specific nitrogen removal rate was 1.48 mgN/(h·gvss). In this process, polyhydroxyalkanoate (PHA) as a critical factor for the highly efficient nitrogen removal (>95%) was approved to be the primary carbon source in the sludge. Because most of the organic matter in raw water was used for denitrification, in the duration of this 160-day experiment, zero discharge of sludge was realized when the effluent suspended solids were 30–50 mg/L. PMID:29435456

Heterotrophic cultivation of Chlorella pyrenoidosa using sucrose as the sole carbon source by co-culture with Rhodotorula glutinis.

PubMed

Wang, Shikai; Wu, Yong; Wang, Xu

2016-11-01

Heterotrophic cultivation of microalgae is a feasible alternative strategy to avoid the light limitation of photoautotrophic culture, but the heterotrophic utilization of disaccharides is difficult for microalgae. Aimed at this problem, a co-culture system was developed by mix culture of C. pyrenoidosa and R. glutinis using sucrose as the sole carbon source. In this system, C. pyrenoidosa could utilize glucose and fructose which were hydrolyzed from sucrose by R. glutinis. The highest specific growth rate and final cell number proportion of algae was 1.02day(-1) and 45%, respectively, when cultured at the initial algal cell number proportion of 95.24% and the final algal cell density was 111.48×10(6)cells/mL. In addition, the lipid content was also promoted due to the synergistic effects in mix culture. This study provides a novel approach using sucrose-riched wastes for the heterotrophic culture of microalgae and may effectively decrease the cost of carbon source. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cultured fungal associates from the deep-sea coral Lophelia pertusa

NASA Astrophysics Data System (ADS)

Galkiewicz, Julia P.; Stellick, Sarah H.; Gray, Michael A.; Kellogg, Christina A.

2012-09-01

The cold-water coral Lophelia pertusa provides important habitat to many deep-sea fishes and invertebrates. Studies of the microbial taxa associated with L. pertusa thus far have focused on bacteria, neglecting the microeukaryotic members. This is the first study to culture fungi from living L. pertusa and to investigate carbon source utilization by the fungal associates. Twenty-seven fungal isolates from seven families, including both filamentous and yeast morphotypes, were cultured from healthy L. pertusa colonies collected from the northern Gulf of Mexico, the West Florida Slope, and the western Atlantic Ocean off the Florida coast. Isolates from different sites were phylogenetically closely related, indicating these genera are widely distributed in association with L. pertusa. Biolog™ Filamentous Fungi microtiter plates were employed to determine the functional capacity of a subset of isolates to grow on varied carbon sources. While four of the isolates exhibited no growth on any provided carbon source, the rest (n=10) grew on 8.3-66.7% of carbon sources available. Carbohydrates, carboxylic acids, and amino acids were the most commonly metabolized carbon sources, with overlap between the carbon sources used and amino acids found in L. pertusa mucus. This study represents the first attempt to characterize a microeukaryotic group associated with L. pertusa. However, the functional role of fungi within the coral holobiont remains unclear.

[Soil microbial functional diversity of different altitude Pinus koraiensis forests].

PubMed

Han, Dong-xue; Wang, Ning; Wang, Nan-nan; Sun, Xue; Feng, Fu-juan

2015-12-01

In order to comprehensively understand the soil microbial carbon utilization characteristics of Pinus koraiensis forests, we took the topsoil (0-5 cm and 5-10 cm) along the 700-1100 m altitude in Changbai Mountains and analyzed the vertical distributed characteristics and variation of microbial functional diversity along the elevation gradient by Biolog microplate method. The results showed that there were significant differences in functional diversity of microbial communities at different elevations. AWCD increased with the extension of incubation time and AWCD at the same soil depth gradually decreased along with increasing altitude; Shannon, Simpson and McIntosh diversity index also showed the same trend with AWCD and three different diversity indices were significantly different along the elevation gradient; Species diversity and functional diversity showed the same variation. The utilization intensities of six categories carbon sources had differences while amino acids were constantly the most dominant carbon source. Principal component analysis (PCA) identified that soil microbial carbon utilization at different altitudes had obvious spatial differentiation, as reflected in the use of carbohydrates, amino acids and carboxylic acids. In addition, the cluster of the microbial diversity indexes and AWCD values of different altitudes showed that the composition of vegetation had a significant impact on soil microbial composition and functional activity.

Utilization of ancient permafrost carbon in headwaters of Arctic fluvial networks.

PubMed

Mann, Paul J; Eglinton, Timothy I; McIntyre, Cameron P; Zimov, Nikita; Davydova, Anna; Vonk, Jorien E; Holmes, Robert M; Spencer, Robert G M

2015-07-24

Northern high-latitude rivers are major conduits of carbon from land to coastal seas and the Arctic Ocean. Arctic warming is promoting terrestrial permafrost thaw and shifting hydrologic flowpaths, leading to fluvial mobilization of ancient carbon stores. Here we describe (14)C and (13)C characteristics of dissolved organic carbon from fluvial networks across the Kolyma River Basin (Siberia), and isotopic changes during bioincubation experiments. Microbial communities utilized ancient carbon (11,300 to >50,000 (14)C years) in permafrost thaw waters and millennial-aged carbon (up to 10,000 (14)C years) across headwater streams. Microbial demand was supported by progressively younger ((14)C-enriched) carbon downstream through the network, with predominantly modern carbon pools subsidizing microorganisms in large rivers and main-stem waters. Permafrost acts as a significant and preferentially degradable source of bioavailable carbon in Arctic freshwaters, which is likely to increase as permafrost thaw intensifies causing positive climate feedbacks in response to on-going climate change.

Mathematical modeling of unicellular microalgae and cyanobacteria metabolism for biofuel production.

PubMed

Baroukh, Caroline; Muñoz-Tamayo, Rafael; Bernard, Olivier; Steyer, Jean-Philippe

2015-06-01

The conversion of microalgae lipids and cyanobacteria carbohydrates into biofuels appears to be a promising source of renewable energy. This requires a thorough understanding of their carbon metabolism, supported by mathematical models, in order to optimize biofuel production. However, unlike heterotrophic microorganisms that utilize the same substrate as sources of energy and carbon, photoautotrophic microorganisms require light for energy and CO2 as carbon source. Furthermore, they are submitted to permanent fluctuating light environments due to outdoor cultivation or mixing inducing a flashing effect. Although, modeling these nonstandard organisms is a major challenge for which classical tools are often inadequate, this step remains a prerequisite towards efficient optimization of outdoor biofuel production at an industrial scale. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of 18 pharmaceuticals on the physiological diversity of edaphic microorganisms.

PubMed

Pino-Otín, Mª Rosa; Muñiz, Selene; Val, Jonatan; Navarro, Enrique

2017-10-01

Pharmaceutical residues can enter the terrestrial environment through the application of recycled water and contaminated biosolids to agricultural soils, were edaphic microfauna can would be threatened. This study thus assessed the effect of 18 widely consumed pharmaceuticals, belonging to four groups: antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), blood lipid-lowering agents (BLLA) and β-blockers, on the physiology of soil microbial communities from a ecological crop field. Biolog EcoPlates, containing 31 of the most common carbon sources found in forest and crop soils, were used to calculate both the averaged well colour development (AWCD), as an indicator of the entire capacity of degrading carbon sources, and the diversity of carbon source utilization, as an indicator of the physiological diversity. The results show that pharmaceuticals impact microbial communities by changing the ability of microbes to metabolize different carbon sources, thus affecting the metabolic diversity of the soil community. The toxicity of the pharmaceuticals was inversely related to the log K ow ; indeed, NSAIDs were the least toxic and antibiotics were the most toxic, while BLLA and β-blockers presented intermediate toxicity. The antibiotic sulfamethoxazole imposed the greatest impact on microbial communities at concentrations from 100 mg/L, followed by the other two antibiotics (trimethoprim and tetracycline) and the β-blocker nadolol. Other chemical parameters (i.e. melting point, molecular weight, pK a or solubility) had little influence on toxicity. Microbial communities exposed to pharmaceuticals having similar physicochemical characteristics presented similar physiological diversity patterns of carbon substrate utilization. These results suggest that the repeated amendment of agricultural soils with biosolids or sludges containing pharmaceutical residuals may result in soil concentrations of concern regarding key ecological functions (i.e. the carbon cycle). Copyright © 2017 Elsevier B.V. All rights reserved.

Ethanolamine utilization in Vibrio alginolyticus

PubMed Central

2012-01-01

Abstract Ethanolamine is used as an energy source by phylogenetically diverse bacteria including pathogens, by the concerted action of proteins from the eut-operon. Previous studies have revealed the presence of eutBC genes encoding ethanolamine-ammonia lyase, a key enzyme that breaks ethanolamine into acetaldehyde and ammonia, in about 100 bacterial genomes including members of gamma-proteobacteria. However, ethanolamine utilization has not been reported for any member of the Vibrio genus. Our comparative genomics study reveals the presence of genes that are involved in ethanolamine utilization in several Vibrio species. Using Vibrio alginolyticus as a model system we demonstrate that ethanolamine is better utilized as a nitrogen source than as a carbon source. Reviewers This article was reviewed by Dr. Lakshminarayan Iyer and Dr. Vivek Anantharaman (nominated by Dr. L Aravind). PMID:23234435

[Effects of carbon sources changes on the property and morphology of 2,4-D degraded aerobic sludge granules].

PubMed

Ma, Jing-Yun; Quan, Xian-Chun; Xiong, Wei-Cong

2010-11-01

This study investigated the changes of the morphology, structure, and capability of removing the target contamination of the aerobic granules pre-cultured with mixed substrates of glucose and 2,4-dichlorophenoxyacetic acid (2,4-D) in a long-time running sequence batch reactor (SBR), when the carbon source transformed into the sole carbon source of 2,4-D. Results showed that when the substrate turned to the sole carbon source of 2,4-D, the aerobic granules still maintained a strong degradation ability to the target contamination; a 2,4-D removal percentage of 99.2% -100% and an average COD removal rate of 85.6% were achieved at the initial 2,4-D concentration of 361-564 mg/L. Carbon source transformation caused certain damages to the original aerobic granule structure, made some parts of granules disintegrated, and led to granule size decline from 513 microm to 302 microm. However, those granules maintained the main body, re-aggregated and grew after a period of adaptation due to their strong resistance to toxicity. Aerobic granules capable of utilizing 2,4-D as the sole carbon source with a good settling ability (SYI 20-40 mL/g) and a mean diameter of 489 microm were finally obtained in this study. Scanning electron microscope (SEM) observation showed that the diversity of granule microbial species was declined when turned to the sole carbon source.

Complete genome sequence of a carbon monoxide-utilizing acetogen, Eubacterium limosum KIST612.

PubMed

Roh, Hanseong; Ko, Hyeok-Jin; Kim, Daehee; Choi, Dong Geon; Park, Shinyoung; Kim, Sujin; Chang, In Seop; Choi, In-Geol

2011-01-01

Eubacterium limosum KIST612 is an anaerobic acetogenic bacterium that uses CO as the sole carbon/energy source and produces acetate, butyrate, and ethanol. To evaluate its potential as a syngas microbial catalyst, we have sequenced the complete 4.3-Mb genome of E. limosum KIST612.

High Temperature Raman Spectroscopy Study of the Conversion of Formate into Oxalate: Search for the Elusive CO 2 2 - Intermediate

NASA Astrophysics Data System (ADS)

Ryan, Charles; Mead, Anna; Lakkaraju, Prasad; Kaczur, Jerry; Bennett, Christopher; Dobbins, Tabbetha

Research on conversion of carbon dioxide into chemicals and fuels has the potential to address three problems of global relevance. (a) By removing carbon dioxide from the atmosphere, we are able to reduce the amount of greenhouse gases in the atmosphere, (b) by converting carbon dioxide into fuels, we are providing pathways for renewable energy sources, (c) by converting carbon dioxide into C2 and higher order compounds, and we are able to generate valuable precursors for organic synthesis. Formate salts are formed by the electrochemical reduction of carbon dioxide in aqueous media. However, in order to increase the utilization of carbon dioxide, methods need to be developed for the conversion of formate into compounds containing two carbon atoms such as oxalate or oxalic acid. Recently, we examined the thermal conversion of sodium formate into sodium oxalate utilizing a hydride ion catalyst. The proposed mechanism for this reaction involves the carbon dioxide dianion. Currently at NASA Goddard Space Flight Center.

Nutrient Dependence of RNase E Essentiality in Escherichia coli

PubMed Central

Tamura, Masaru; Moore, Christopher J.

2013-01-01

Escherichia coli cells normally require RNase E activity to form colonies (colony-forming ability [CFA]). The CFA-defective phenotype of cells lacking RNase E is partly reversed by overexpression of the related endoribonuclease RNase G or by mutation of the gene encoding the RNA helicase DeaD. We found that the carbon source utilization by rne deaD doubly mutant bacteria differs from that of rne+ cells and from that of cells mutated in deaD alone and that the loss of rne function in these bacteria limits conversion of the glycolytic pathway product phosphoenolpyruvate to the tricarboxylic acid (TCA) cycle intermediate oxaloacetic acid. We show that the mechanism underlying this effect is reduced production of the enzyme phosphoenolpyruvate carboxylase (PPC) and that adventitious overexpression of PPC, which facilitates phosphoenolpyruvate utilization and connects the glycolytic pathway with the TCA cycle, restored CFA to rne deaD mutant bacteria cultured on carbon sources that otherwise were unable to sustain growth. We further show that bacteria producing full-length RNase E, which allows formation of degradosomes, have nutritional requirements different from those of cells supplied with only the N-terminal catalytic region of RNase E and that mitigation of RNase E deficiency by overexpression of a related RNase, RNase G, is also affected by carbon source. Our results reveal previously unsuspected effects of RNase E deficiency and degradosome formation on nutrient utilization by E. coli cells. PMID:23275245

Carbon transfer from magnesia-graphite ladle refractories to ultra-low carbon steel

NASA Astrophysics Data System (ADS)

Russo, Andrew Arthur

Ultra-low carbon steels are utilized in processes which require maximum ductility. Increases in interstitial carbon lower the ductility of steel; therefore, it is important to examine possible sources of carbon. The refractory ladle lining is one such source. Ladle refractories often contain graphite for its desirable thermal shock and slag corrosion resistance. This graphite is a possible source of carbon increase in ultra-low carbon steels. The goal of this research is to understand and evaluate the mechanisms by which carbon transfers to ultra-low carbon steel from magnesia-graphite ladle refractory. Laboratory dip tests were performed in a vacuum induction furnace under an argon atmosphere to investigate these mechanisms. Commercial ladle refractories with carbon contents between 4-12 wt% were used to investigate the effect of refractory carbon content. Slag-free dip tests and slag-containing dip tests with varying MgO concentrations were performed to investigate the influence of slag. Carbon transfer to the steel was controlled by steel penetrating into the refractory and dissolving carbon in dip tests where no slag was present. The rate limiting step for this mechanism is convective mass transport of carbon into the bulk steel. No detectable carbon transfer occurred in dip tests with 4 and 6 wt%C refractories without slag because no significant steel penetration occurred. Carbon transfer was controlled by the corrosion of refractory by slag in dip tests where slag was present.

Measurements of carbon utilization by single bacterial species in sterile soil: insights into Rhizobium spp.

PubMed

Wigley, K; Wakelin, S A; Moot, D J; Hammond, S; Ridgway, H J

2016-08-01

The aim of this work was to develop a tool to investigate the influence of soil factors on carbon utilization activity of single micro-organisms. The assay for Rhizobium leguminosarum bv. trifolii in γ-irradiated soil, using the MicroResp(™) system, was optimized for sterility, incubation time, and moisture level. The optimized method was validated with experiments that assessed (i) differences in C utilization of different rhizobia strains and (ii) how this was affected by soil type. Carbon utilization differed among strains of the same species (and symbiovar), but some strains were more responsive to the soil environment than others. This novel modification of the MicroResp(™) has enabled the scope of carbon-utilization patterns of single strains of bacteria, such as Rh. leguminosarum bv. trifolii, to be studied in soil. The system is a new tool with applications in microbial ecology adaptable to the study of many culturable bacterial and fungal soil-borne taxa. It will allow measurement of a micro-organism's ability to utilize common C sources released in rhizosphere exudates to be measured in a physical soil background. This knowledge may improve selection efficiency and deployment of commercial microbial inoculants. © 2016 The Society for Applied Microbiology.

The Glycolytic Versatility of Bacteroides uniformis CECT 7771 and Its Genome Response to Oligo and Polysaccharides

PubMed Central

Benítez-Páez, Alfonso; Gómez del Pulgar, Eva M.; Sanz, Yolanda

2017-01-01

Bacteroides spp. are dominant components of the phylum Bacteroidetes in the gut microbiota and prosper in glycan enriched environments. However, knowledge of the machinery of specific species isolated from humans (like Bacteroides uniformis) contributing to the utilization of dietary and endogenous sources of glycans and their byproducts is limited. We have used the cutting-edge nanopore-based technology to sequence the genome of B. uniformis CECT 7771, a human symbiont with a proven pre-clinical efficacy on metabolic and immune dysfunctions in obesity animal models. We have also used massive sequencing approaches to distinguish the genome expression patterns in response to carbon sources of different complexity during growth. At genome-wide level, our analyses globally demonstrate that B. uniformis strains exhibit an expanded glycolytic capability when compared with other Bacteroides species. Moreover, by studying the growth and whole-genome expression of B. uniformis CECT 7771 in response to different carbon sources, we detected a differential growth fitness and expression patterns across the genome depending on the carbon source of the culture media. The dietary fibers used exerted different effects on B. uniformis CECT 7771 activating different molecular pathways and, therefore, allowing the production of different metabolite types with potential impact on gut health. The genome and transcriptome analysis of B. uniformis CECT 7771, in response to different carbon sources, shows its high versatility to utilize both dietary and endogenous glycans along with the production of potentially beneficial end products for both the bacterium and the host, pointing to a mechanistic basis of a mutualistic relationship. PMID:28971068

The aldehyde dehydrogenase, AldA, is essential for L-1,2-propanediol utilization in laboratory-evolved Escherichia coli.

PubMed

Aziz, Ramy K; Monk, Jonathan M; Andrews, Kathleen A; Nhan, Jenny; Khaw, Valerie L; Wong, Hesper; Palsson, Bernhard O; Charusanti, Pep

2017-01-01

Most Escherichia coli strains are naturally unable to grow on 1,2-propanediol (PDO) as a sole carbon source. Recently, however, a K-12 descendent E. coli strain was evolved to grow on 1,2-PDO, and it was hypothesized that this evolved ability was dependent on the aldehyde dehydrogenase, AldA, which is highly conserved among members of the family Enterobacteriacea. To test this hypothesis, we first performed computational model simulation, which confirmed the essentiality of the aldA gene for 1,2-PDO utilization by the evolved PDO-degrading E. coli. Next, we deleted the aldA gene from the evolved strain, and this deletion was sufficient to abolish the evolved phenotype. On re-introducing the gene on a plasmid, the evolved phenotype was restored. These findings provide experimental evidence for the computationally predicted role of AldA in 1,2-PDO utilization, and represent a good example of E. coli robustness, demonstrated by the bacterial deployment of a generalist enzyme (here AldA) in multiple pathways to survive carbon starvation and to grow on a non-native substrate when no native carbon source is available. Copyright © 2016 Elsevier GmbH. All rights reserved.

Next-Gen 3: Sequencing, Modeling, and Advanced Biofuels - Final Technical Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zengler, Karsten; Palsson, Bernhard; Lewis, Nathan

Successful, scalable implementation of biofuels is dependent on the efficient and near complete utilization of diverse biomass sources. One approach is to utilize the large recalcitrant biomass fraction (or any organic waste stream) through the thermochemical conversion of organic compounds to syngas, a mixture of carbon monoxide (CO), carbon dioxide (CO 2), and hydrogen (H 2), which can subsequently be metabolized by acetogenic microorganisms to produce next-gen biofuels. The goal of this proposal was to advance the development of the acetogen Clostridium ljungdahlii as a chassis organism for next-gen biofuel production from cheap, renewable sources and to detail the interconnectivitymore » of metabolism, energy conservation, and regulation of acetogens using next-gen sequencing and next-gen modeling. To achieve this goal we determined optimization of carbon and energy utilization through differential translational efficiency in C. ljungdahlii. Furthermore, we reconstructed a next-generation model of all major cellular processes, such as macromolecular synthesis and transcriptional regulation and deployed this model to predicting proteome allocation, overflow metabolism, and metal requirements in this model acetogen. In addition we explored the evolutionary significance of tRNA operon structure using the next-gen model and determined the optimal operon structure for bioproduction. Our study substantially enhanced the knowledgebaase for chemolithoautotrophs and their potential for advanced biofuel production. It provides next-generation modeling capability, offer innovative tools for genome-scale engineering, and provide novel methods to utilize next-generation models for the design of tunable systems that produce commodity chemicals from inexpensive sources.« less

Carbon-dependent alleviation of ammonia toxicity for algae cultivation and associated mechanisms exploration.

PubMed

Lu, Qian; Chen, Paul; Addy, Min; Zhang, Renchuan; Deng, Xiangyuan; Ma, Yiwei; Cheng, Yanling; Hussain, Fida; Chen, Chi; Liu, Yuhuan; Ruan, Roger

2018-02-01

Ammonia toxicity in wastewater is one of the factors that limit the application of algae technology in wastewater treatment. This work explored the correlation between carbon sources and ammonia assimilation and applied a glucose-assisted nitrogen starvation method to alleviate ammonia toxicity. In this study, ammonia toxicity to Chlorella sp. was observed when NH 3 -N concentration reached 28.03mM in artificial wastewater. Addition of alpha-ketoglutarate in wastewater promoted ammonia assimilation, but low utilization efficiency and high cost of alpha-ketoglutarate limits its application in wastewater treatment. Comparison of three common carbon sources, glucose, citric acid, and sodium bicarbonate, indicates that in terms of ammonia assimilation, glucose is the best carbon source. Experimental results suggest that organic carbon with good ability of generating energy and hydride donor may be critical to ammonia assimilation. Nitrogen starvation treatment assisted by glucose increased ammonia removal efficiencies and algal viabilities. Copyright © 2017 Elsevier Ltd. All rights reserved.

Microbial Transformations of Selenium

PubMed Central

Doran, J. W.; Alexander, M.

1977-01-01

Resting cell suspensions of a strain of Corynebacterium isolated from soil formed dimethyl selenide from selenate, selenite, elemental selenium, selenomethionine, selenocystine, and methaneseleninate. Extracts of the bacterium catalyzed the production of dimethyl selenide from selenite, elemental selenium, and methaneseleninate, and methylation of the inorganic Se compounds was enhanced by S-adenosylmethionine. Neither trimethylselenonium nor methaneselenonate was metabolized by the Corynebacterium. Resting cell suspensions of a methionine-utilizing pseudomonad converted selenomethionine to dimethyl diselenide. Six of 10 microorganisms able to grow on cystine used selenocystine as a sole source of carbon and formed elemental selenium, and one of the isolates, a pseudomonad, was found also to produce selenide. Soil enrichments converted trimethylselenonium to dimethyl selenide. Bacteria capable of utilizing trimethylselenonium, dimethyl selenide, and dimethyl diselenide as carbon sources were isolated from soil. PMID:16345188

Microbial Utilization of Free and Clay-Bound Insecticidal Toxins from Bacillus thuringiensis and Their Retention of Insecticidal Activity after Incubation with Microbes

PubMed Central

Koskella, J.; Stotzky, G.

1997-01-01

The insecticidal toxins produced by Bacillus thuringiensis subspp. kurstaki and tenebrionis were resistant when bound on clays, but not when free, to utilization by pure and mixed cultures of microbes as sources of carbon and carbon plus nitrogen, and their availability as a nitrogen source was reduced. The bound toxins retained insecticidal activity both before and after exposure to microbes or pronase. The insecticidal activity of the toxins persisted for 40 days (the longest time evaluated) in nonsterile soil continuously maintained at the -33-kPa water tension and room temperature, alternately air dried and rewetted to the -33-kPa water tension, or alternately frozen and thawed, although alternate drying and wetting reduced the activity. PMID:16535692

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wear, Jr., John Edmund

The objective of this study was to examine the hypothesis that select functional groups of bacteria from pristine sites have an innate ability to degrade synthetic aromatics that often contaminate groundwater environments,due to exposure to naturally occurring recalcitrant aromatics in their environment. This study demonstrates that subsurface microbial communities are capable of utilizing lignin and humic acid breakdown products. Utilizers of these compounds were found to be present in most all the wells tested. Even the deepest aquifer tested had utilizers present for all six of the aromatics tested. Highest counts for the aromatics tested were observed with the naturallymore » occurring breakdown products of either lignin or humic acid. Carboxylic acids were found to be an important sole carbon source for groundwater bacteria possibly explained by the fact that they are produced by the oxidative cleavage of aromatic ring structures. The carbohydrate sole carbon sources that demonstrated the greatest densities were ones commonly associated with humics. This study indicates that utilization of naturally occurring aromatic compounds in the subsurface is an important nutritional source for groundwater bacteria. In addition, it suggests that adaptation to naturally occurring recalcitrant substrates is the origin of degradative pathways for xenobiotic compounds with analogous structure. This work has important implications for in situ bioremediation as a method of environmental cleanup.« less

Cultured fungal associates from the deep-sea coral Lophelia pertusa

USGS Publications Warehouse

Galkiewicz, Julia P.; Stellick, Sarah H.; Gray, Michael A.; Kellogg, Christina A.

2012-01-01

The cold-water coral Lophelia pertusa provides important habitat to many deep-sea fishes and invertebrates. Studies of the microbial taxa associated with L. pertusa thus far have focused on bacteria, neglecting the microeukaryotic members. This is the first study to culture fungi from living L. pertusa and to investigate carbon source utilization by the fungal associates. Twenty-seven fungal isolates from seven families, including both filamentous and yeast morphotypes, were cultured from healthy L. pertusa colonies collected from the northern Gulf of Mexico, the West Florida Slope, and the western Atlantic Ocean off the Florida coast. Isolates from different sites were phylogenetically closely related, indicating these genera are widely distributed in association with L. pertusa. Biolog™ Filamentous Fungi microtiter plates were employed to determine the functional capacity of a subset of isolates to grow on varied carbon sources. While four of the isolates exhibited no growth on any provided carbon source, the rest (n=10) grew on 8.3–66.7% of carbon sources available. Carbohydrates, carboxylic acids, and amino acids were the most commonly metabolized carbon sources, with overlap between the carbon sources used and amino acids found in L. pertusa mucus. This study represents the first attempt to characterize a microeukaryotic group associated with L. pertusa. However, the functional role of fungi within the coral holobiont remains unclear.

The Crc protein inhibits the production of polyhydroxyalkanoates in Pseudomonas putida under balanced carbon/nitrogen growth conditions.

PubMed

La Rosa, Ruggero; de la Peña, Fernando; Prieto, María Axiliadora; Rojo, Fernando

2014-01-01

Pseudomonas putida synthesizes polyhydroxyalkanoates (PHAs) as storage compounds. PHA synthesis is more active when the carbon source is in excess and the nitrogen source is limiting, but can also occur at a lower rate under balanced carbon/nitrogen ratios. This work shows that PHA synthesis is controlled by the Crc global regulator, a protein that optimizes carbon metabolism by inhibiting the expression of genes involved in the use of non-preferred carbon sources. Crc acts post-transcriptionally. The mRNAs of target genes contain characteristic catabolite activity (CA) motifs near the ribosome binding site. Sequences resembling CA motifs can be predicted for the phaC1 gene, which codes for a PHA polymerase, and for phaI and phaF, which encode proteins associated to PHA granules. Our results show that Crc inhibits the translation of phaC1 mRNA, but not that of phaI or phaF, reducing the amount of PHA accumulated in the cell. Crc inhibited PHA synthesis during exponential growth in media containing a balanced carbon/nitrogen ratio. No inhibition was seen when the carbon/nitrogen ratio was imbalanced. This extends the role of Crc beyond that of controlling the hierarchical utilization of carbon sources and provides a link between PHA synthesis and the global regulatory networks controlling carbon flow. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

Engineering an Obligate Photoautotrophic Cyanobacterium to Utilize Glycerol for Growth and Chemical Production.

PubMed

Kanno, Masahiro; Atsumi, Shota

2017-01-20

Cyanobacteria have attracted much attention as a means to directly recycle carbon dioxide into valuable chemicals that are currently produced from petroleum. However, the titers and productivities achieved are still far below the level required in industry. To make a more industrially applicable production scheme, glycerol, a byproduct of biodiesel production, can be used as an additional carbon source for photomixotrophic chemical production. Glycerol is an ideal candidate due to its availability and low cost. In this study, we found that a heterologous glycerol respiratory pathway enabled Synechococcus elongatus PCC 7942 to utilize extracellular glycerol. The engineered strain produced 761 mg/L of 2,3-butanediol in 48 h with a 290% increase over the control strain under continuous light conditions. Glycerol supplementation also allowed for continuous cell growth and 2,3-butanediol production in diurnal light conditions. These results highlight the potential of glycerol as an additional carbon source for photomixotrophic chemical production in cyanobacteria.

Carbon Nanotubes, Nanocrystal Forms, and Complex Nanoparticle Aggregates in common fuel-gas combustion sources and the ambient air

NASA Astrophysics Data System (ADS)

Murr, L. E.; Bang, J. J.; Esquivel, E. V.; Guerrero, P. A.; Lopez, D. A.

2004-06-01

Aggregated multiwall carbon nanotubes (with diameters ranging from ˜3 to 30nm) and related carbon nanocrystal forms ranging in size from 0.4 to 2 μm (average diameter) have been collected in the combustion streams for methane/air, natural gas/air, and propane gas/air flames using a thermal precipitator. Individual particle aggregates were collected on carbon/formvar-coated 3mm nickel grids and examined in a transmission electron microscope, utilizing bright-field imaging, selected-area electron diffraction analysis, and energy-dispersive X-ray spectrometry techniques. The natural gas and propane gas sources were domestic (kitchen) stoves, and similar particle aggregates collected in the outdoor air were correspondingly identified as carbon nanocrystal aggregates and sometimes more complex aggregates of silica nanocrystals intermixed with the carbon nanotubes and other carbon nanocrystals. Finally, and in light of the potential for methane-series gas burning as major sources of carbon nanocrystal aggregates in both the indoor and outdoor air, data for natural gas consumption and corresponding asthma deaths and incidence are examined with a degree of speculation regarding any significance in the correlations.

Year-round Source Contributions of Fossil Fuel and Biomass Combustion to Elemental Carbon on the North Slope Alaska Utilizing Radiocarbon Analysis

NASA Astrophysics Data System (ADS)

Barrett, T. E.; Gustafsson, O.; Winiger, P.; Moffett, C.; Back, J.; Sheesley, R. J.

2015-12-01

It is well documented that the Arctic has undergone rapid warming at an alarming rate over the past century. Black carbon (BC) affects the radiative balance of the Arctic directly and indirectly through the absorption of incoming solar radiation and by providing a source of cloud and ice condensation nuclei. Among atmospheric aerosols, BC is the most efficient absorber of light in the visible spectrum. The solar absorbing efficiency of BC is amplified when it is internally mixed with sulfates. Furthermore, BC plumes that are fossil fuel dominated have been shown to be approximately 100% more efficient warming agents than biomass burning dominated plumes. The renewal of offshore oil and gas exploration in the Arctic, specifically in the Chukchi Sea, will introduce new BC sources to the region. This study focuses on the quantification of fossil fuel and biomass combustion sources to atmospheric elemental carbon (EC) during a year-long sampling campaign in the North Slope Alaska. Samples were collected at the Department of Energy Atmospheric Radiation Measurement (ARM) climate research facility in Barrow, AK, USA. Particulate matter (PM10) samples collected from July 2012 to June 2013 were analyzed for EC and sulfate concentrations combined with radiocarbon (14C) analysis of the EC fraction. Radiocarbon analysis distinguishes fossil fuel and biomass burning contributions based on large differences in end members between fossil and contemporary carbon. To perform isotope analysis on EC, it must be separated from the organic carbon fraction of the sample. Separation was achieved by trapping evolved CO2 produced during EC combustion in a cryo-trap utilizing liquid nitrogen. Radiocarbon results show an average fossil contribution of 85% to atmospheric EC, with individual samples ranging from 47% to 95%. Source apportionment results will be combined with back trajectory (BT) analysis to assess geographic source region impacts on the EC burden in the western Arctic.

Polymer-encapsulated carbon capture liquids that tolerate precipitation of solids for increased capacity

DOEpatents

Aines, Roger D; Bourcier, William L; Spadaccini, Christopher M; Stolaroff, Joshuah K

2015-02-03

A system for carbon dioxide capture from flue gas and other industrial gas sources utilizes microcapsules with very thin polymer shells. The contents of the microcapsules can be liquids or mixtures of liquids and solids. The microcapsules are exposed to the flue gas and other industrial gas and take up carbon dioxide from the flue gas and other industrial gas and eventual precipitate solids in the capsule.

Fungal Survival in a Chemosynthetic Ecosystem

NASA Astrophysics Data System (ADS)

Kiel Reese, B.; Sobol, M. S.; Hoshino, T.; Inagaki, F.; Eder, E.; Nicora, C. D.; Heyman, H. M.; Kyle, J. E.; Hoyt, D. W.; Tfaily, M. M.; Metz, T. O.

2018-05-01

Fungi possess metabolic pathways capable of utilizing previously considered non-bioavailable energy reserves. Metabolically active fungi occupy a unique niche within the subsurface, providing an organic carbon source for heterotrophic prokaryotes.

Acidotolerant Bacteria and Fungi as a Sink of Methanol-Derived Carbon in a Deciduous Forest Soil

PubMed Central

Morawe, Mareen; Hoeke, Henrike; Wissenbach, Dirk K.; Lentendu, Guillaume; Wubet, Tesfaye; Kröber, Eileen; Kolb, Steffen

2017-01-01

Methanol is an abundant atmospheric volatile organic compound that is released from both living and decaying plant material. In forest and other aerated soils, methanol can be consumed by methanol-utilizing microorganisms that constitute a known terrestrial sink. However, the environmental factors that drive the biodiversity of such methanol-utilizers have been hardly resolved. Soil-derived isolates of methanol-utilizers can also often assimilate multicarbon compounds as alternative substrates. Here, we conducted a comparative DNA stable isotope probing experiment under methylotrophic (only [13C1]-methanol was supplemented) and combined substrate conditions ([12C1]-methanol and alternative multi-carbon [13Cu]-substrates were simultaneously supplemented) to (i) identify methanol-utilizing microorganisms of a deciduous forest soil (European beech dominated temperate forest in Germany), (ii) assess their substrate range in the soil environment, and (iii) evaluate their trophic links to other soil microorganisms. The applied multi-carbon substrates represented typical intermediates of organic matter degradation, such as acetate, plant-derived sugars (xylose and glucose), and a lignin-derived aromatic compound (vanillic acid). An experimentally induced pH shift was associated with substantial changes of the diversity of active methanol-utilizers suggesting that soil pH was a niche-defining factor of these microorganisms. The main bacterial methanol-utilizers were members of the Beijerinckiaceae (Bacteria) that played a central role in a detected methanol-based food web. A clear preference for methanol or multi-carbon substrates as carbon source of different Beijerinckiaceae-affiliated phylotypes was observed suggesting a restricted substrate range of the methylotrophic representatives. Apart from Bacteria, we also identified the yeasts Cryptococcus and Trichosporon as methanol-derived carbon-utilizing fungi suggesting that further research is needed to exclude or prove methylotrophy of these fungi. PMID:28790984

Role of vegetation and edaphic factors in controlling diversity and use of different carbon sources in semi-arid ecosystems

NASA Astrophysics Data System (ADS)

Lohse, K. A.; McLain, J. E.; Harman, C. J.; Sivapalan, M.; Troch, P. A.

2010-12-01

Microbially-mediated soil carbon cycling is closely linked to soil moisture and temperature. Climate change is predicted to increase intra-annual precipitation variability (i.e. less frequent yet more intense precipitation events) and alter biogeochemical processes due to shifts in soil moisture dynamics and inputs of carbon. However, the responses of soil biology and chemistry to predicted climate change, and their concomitant feedbacks on ecosystem productivity and biogeochemical processes are poorly understood. We collected soils at three different elevations in the Santa Catalina Mountains, AZ and quantified carbon utilization during pre-monsoon precipitation conditions. Contrasting parent materials (schist and granite) were paired at each elevation. We expected climate to determine the overall activity of soil fungal and bacterial communities and diversity of soil C utilization, and differences in parent material to modify these responses through controls on soil physical properties. We used EcoPlateTM C utilization assays to determine the relative abundance of soil bacterial and fungal populations and rate and diversity of carbon utilization. Additional plates were incubated with inhibitors selective to fungal or bacterial activity to assess relative contribution of these microbial groups to overall C utilization. We analyzed soils for soil organic matter, total C and N, particle size analysis and soil moisture content via both gravimetric and volumetric methods to assess the influences of soil physical and chemical properties on the measured biological responses. Consistent with our expectations, overall microbial activity was highest at the uppermost conifer elevation sites compared to the middle and lower elevation sites. In contrast to our expectations, however, overall activity was lower at the mid elevation oak woodland sites compared to the low elevation desert sites. Also consistent with our expectations was the observation that overall activities were consistently higher in schist parent material compared to granite. Though differences between canopy and intercanopy carbon utilization were subtle, the diversity of carbon utilization differed, suggesting a potential role of root exudates in governing C utilization in these semiarid soils. Findings from this study suggest that soil physical properties due to parent material have primary impacts in constraining microbial growth and carbon utilization under changing climate conditions.

Comparative genomic analysis of carbon and nitrogen assimilation mechanisms in three indigenous bioleaching bacteria: predictions and validations

PubMed Central

Levicán, Gloria; Ugalde, Juan A; Ehrenfeld, Nicole; Maass, Alejandro; Parada, Pilar

2008-01-01

Background Carbon and nitrogen fixation are essential pathways for autotrophic bacteria living in extreme environments. These bacteria can use carbon dioxide directly from the air as their sole carbon source and can use different sources of nitrogen such as ammonia, nitrate, nitrite, or even nitrogen from the air. To have a better understanding of how these processes occur and to determine how we can make them more efficient, a comparative genomic analysis of three bioleaching bacteria isolated from mine sites in Chile was performed. This study demonstrated that there are important differences in the carbon dioxide and nitrogen fixation mechanisms among bioleaching bacteria that coexist in mining environments. Results In this study, we probed that both Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans incorporate CO2 via the Calvin-Benson-Bassham cycle; however, the former bacterium has two copies of the Rubisco type I gene whereas the latter has only one copy. In contrast, we demonstrated that Leptospirillum ferriphilum utilizes the reductive tricarboxylic acid cycle for carbon fixation. Although all the species analyzed in our study can incorporate ammonia by an ammonia transporter, we demonstrated that Acidithiobacillus thiooxidans could also assimilate nitrate and nitrite but only Acidithiobacillus ferrooxidans could fix nitrogen directly from the air. Conclusion The current study utilized genomic and molecular evidence to verify carbon and nitrogen fixation mechanisms for three bioleaching bacteria and provided an analysis of the potential regulatory pathways and functional networks that control carbon and nitrogen fixation in these microorganisms. PMID:19055775

Evidence of nutrient partitioning in coexisting deep-sea echinoids, and seasonal dietary shifts in seasonal breeders: Perspectives from stable isotope analyses

NASA Astrophysics Data System (ADS)

Stevenson, Angela; Mitchell, Fraser J. G.

2016-02-01

The role of nutrition in echinoid growth and reproduction, as well as the mechanisms utilized to cope with food limitations in the deep sea remains under studied. We investigate echinoid feeding mechanisms within deep-sea submarine canyons in the NE Atlantic using a stable-isotope approach. Ten echinoid species were collected with a remotely operated vehicle. δ13C and δ15N stable isotope analyses (SIA) were conducted on echinoid tissues in order to investigate food sources assimilated with respect to nutrient partitioning between coexisting taxa, and seasonal dietary changes in food supply. Gut content analysis was conducted in conjunction with SIA. Echinoid taxa spanned three benthic trophic levels. This large trophic range might suggest an expansion of the trophic niches of echinoid taxa possibly to reduce interspecific competition for limited food resources. Evidence of nutrient partitioning among coexisting taxa was also found in the carbon data. Significant interspecific differences were found in the δ13C signatures of the somatic and reproductive tissues suggesting that different sources of carbon are assimilated into all tissues after the deposition of phytodetritus has taken place on the deep sea floor. However, this pattern differed for the data obtained before the deposition of phytodetritus; similar sources of carbon were assimilated into somatic tissues of different taxa, while some of these different taxa utilized significantly different sources of carbon to manufacture their reproductive tissues. While specific food sources could not be resolved from the carbon data of the present study, enriched δ15N values suggest that echinoids incorporate foods with distinctly higher δ15N values than that of POM and sediment, which could result from opportunistic feeding as well as bioerosion of the live coral framework and consequent grazing of fauna attached to the dead coral infrastructure. Seasonally deposited phytodetritus was incorporated into the reproductive tissues of the seasonal breeder, Gracilechinus alexandri, but not those of continuous breeders, Cidaroida and Echinothurioida. The material however was also found to support somatic tissue growth in cidaroids. These results suggest that seasonal breeders might utilize surface-derived phytodetritus to manufacture reproductive tissues, while continuous breeders might only utilize it for somatic tissue growth or not at all. Results for seasonal dietary shifts were compromised by poor spatial repeatability and thus require further investigation to understand better the role of phytodetritus in fuelling the growth and reproduction of deep-sea echinoids.

A review of ion sources for medical accelerators (invited)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muramatsu, M.; Kitagawa, A.

2012-02-15

There are two major medical applications of ion accelerators. One is a production of short-lived isotopes for radionuclide imaging with positron emission tomography and single photon emission computer tomography. Generally, a combination of a source for negative ions (usually H- and/or D-) and a cyclotron is used; this system is well established and distributed over the world. Other important medical application is charged-particle radiotherapy, where the accelerated ion beam itself is being used for patient treatment. Two distinctly different methods are being applied: either with protons or with heavy-ions (mostly carbon ions). Proton radiotherapy for deep-seated tumors has become widespreadmore » since the 1990s. The energy and intensity are typically over 200 MeV and several 10{sup 10} pps, respectively. Cyclotrons as well as synchrotrons are utilized. The ion source for the cyclotron is generally similar to the type for production of radioisotopes. For a synchrotron, one applies a positive ion source in combination with an injector linac. Carbon ion radiotherapy awakens a worldwide interest. About 6000 cancer patients have already been treated with carbon beams from the Heavy Ion Medical Accelerator in Chiba at the National Institute of Radiological Sciences in Japan. These clinical results have clearly verified the advantages of carbon ions. Heidelberg Ion Therapy Center and Gunma University Heavy Ion Medical Center have been successfully launched. Several new facilities are under commissioning or construction. The beam energy is adjusted to the depth of tumors. It is usually between 140 and 430 MeV/u. Although the beam intensity depends on the irradiation method, it is typically several 10{sup 8} or 10{sup 9} pps. Synchrotrons are only utilized for carbon ion radiotherapy. An ECR ion source supplies multi-charged carbon ions for this requirement. Some other medical applications with ion beams attract developer's interests. For example, the several types of accelerators are under development for the boron neutron capture therapy. This treatment is conventionally demonstrated by a nuclear reactor, but it is strongly expected to replace the reactor by the accelerator. We report status of ion source for medical application and such scope for further developments.« less

Peats from West Kalimantan Province, Indonesia: The Distribution, Formation, Disturbances, Utilization and Conservation

NASA Astrophysics Data System (ADS)

Anshari, G. Z.

2011-12-01

A major portion of tropical peats, approximately between 180,000 and 210,000 km2, occurs in Indonesia. Peat is a water body that preserves and stores enormous organic Carbon of dead biomass vegetation. In a natural state, peat helps to maintain Carbon balance, hydrological cycle, and supply of dissolved and particulate organic matters into adjacent waters. Peat disturbances drive the change from Carbon sink function into Carbon source. This paper aims to discuss variability of tropical peats and peat degradation in West Kalimantan Province. The discussions include extent and formation, biodiversity, Carbon and water storage, major properties, utilization, peat disturbances (i.e. logging, forest conversion, drainage affects, and recurrent peat fires), and peat conservation. Management options for reducing peat fires and developing sustainable peat utilization are also explored. Data were collected from both coastal and inland peats in West Kalimantan Province. This paper declares that degradation of tropical peats in Indonesia is strongly associated with anthropogenic fires, peat forest conversion, and logging. To reduce speeds of peat degradation, the current utilization of peats needs being more intensive than extensive, and preventing water table drop by managing excessive drainage that leads to substantial decline of moisture in the upper peat layer, which is subsequently dry and flammable.

Folate-Dependent Purine Nucleotide Biosynthesis in Humans.

PubMed

Baggott, Joseph E; Tamura, Tsunenobu

2015-09-01

Purine nucleotide biosynthesis de novo (PNB) requires 2 folate-dependent transformylases-5'-phosphoribosyl-glycinamide (GAR) and 5'-phosphoribosyl-5-aminoimidazole-4-carboxamide (AICAR) transformylases-to introduce carbon 8 (C8) and carbon 2 (C2) into the purine ring. Both transformylases utilize 10-formyltetrahydrofolate (10-formyl-H4folate), where the formyl-carbon sources include ring-2-C of histidine, 3-C of serine, 2-C of glycine, and formate. Our findings in human studies indicate that glycine provides the carbon for GAR transformylase (exclusively C8), whereas histidine and formate are the predominant carbon sources for AICAR transformylase (C2). Contrary to the previous notion, these carbon sources may not supply a general 10-formyl-H4folate pool, which was believed to equally provide carbons to C8 and C2. To explain these phenomena, we postulate that GAR transformylase is in a complex with the trifunctional folate-metabolizing enzyme (TFM) and serine hydroxymethyltransferase to channel carbons of glycine and serine to C8. There is no evidence for channeling carbons of histidine and formate to AICAR transformylase (C2). GAR transformylase may require the TFM to furnish 10-formyl-H4folate immediately after its production from serine to protect its oxidation to 10-formyldihydrofolate (10-formyl-H2folate), whereas AICAR transformylase can utilize both 10-formyl-H2folate and 10-formyl-H4folate. Human liver may supply AICAR to AICAR transformylase in erythrocytes/erythroblasts. Incorporation of ring-2-C of histidine and formate into C2 of urinary uric acid presented a circadian rhythm with a peak in the morning, which corresponds to the maximum DNA synthesis in the bone marrow, and it may be useful in the timing of the administration of drugs that block PNB for the treatment of cancer and autoimmune disease. © 2015 American Society for Nutrition.

Origins, fates, and ramifications of natural organic compounds of wetlands

Treesearch

Robert G. Wetzel

2000-01-01

Much of the organic carbon for heterotrophic metabolism in aquatic ecosystems is soluble and derived from structural compounds of higher plants of terrestrial and wetland-littoral sources of both lake and river ecosystems. The chemical recalcitrance of this organic matter and its oxidative utilization are fundamentally different from many sources within the aquatic...

The Potential Role of Formate for Synthesis and Life in Serpentinization Systems

NASA Astrophysics Data System (ADS)

Lang, S. Q.; Frueh-Green, G. L.; Bernasconi, S. M.; Brazelton, W. J.; McGonigle, J. M.

2016-12-01

The high hydrogen concentrations produced during water-rock serpentinization reactions provide abundant thermodynamic energy that can drive the synthesis of organic compounds both biotically and abiotically. We investigated the synthesis of abiotic carbon and the metabolic pathways of the microbial inhabitants of the high energy but low diversity serpentinite-hosted Lost City Hydrothermal Field. High concentrations of the organic acid formate can be attributed to two sources. In some locations formate lacks detectable 14C, demonstrating it was formed abiotically from mantle-derived CO2. In other locations there is an additional modern contribution to the formate pool, potentially indicating active cycling with modern seawater dissolved inorganic carbon by microorganisms. The presence of this carbon source is likely critical for the survival of the subsurface microbial communities that inhabit alkaline serpentinization environments, where inorganic carbon is severely limited. Archaeal lipids produced by the Lost City Methanosarcinales (LCMS) also largely lack 14C, requiring their carbon source to be similarly 14C-free. Metagenomic evidence suggests that the LCMS could use formate for methanogenesis and, altogether, the data suggests that these organisms cannot rely on inorganic carbon as their carbon source and substrate for methanogenesis. Considering the lack of dissolved inorganic carbon in this system, the ability to utilize formate may have been a key evolutionary adaptation for survival in serpentinite-hosted environments. In the Lost City system, the LCMS apparently rely upon an abiotically produced organic carbon source, which may enable the Lost City microbial ecosystem to survive in the absence of photosynthesis or its byproducts.

DEVELOP METHOD FOR THE DETERMINATION OF DISINFECTION BY-PRODUCT FORMATION POTENTIAL (DBP-FP) AND INSTRUMENT DETECTION SYSTEM FOR MONITORING DBP-FP IN DRINKING WATER

EPA Science Inventory

EPA requires drinking water utilities to monitor source water to determine the need for treatment to remove the precursors (natural organic matter {NOM}) of disinfection by-products (DBPs). Currently, drinking water utilities use total organic carbon (TOC), dissolved organic car...

Utilization of Glyphosate as Phosphate Source: Biochemistry and Genetics of Bacterial Carbon-Phosphorus Lyase

PubMed Central

Zechel, David L.; Jochimsen, Bjarne

2014-01-01

SUMMARY After several decades of use of glyphosate, the active ingredient in weed killers such as Roundup, in fields, forests, and gardens, the biochemical pathway of transformation of glyphosate phosphorus to a useful phosphorus source for microorganisms has been disclosed. Glyphosate is a member of a large group of chemicals, phosphonic acids or phosphonates, which are characterized by a carbon-phosphorus bond. This is in contrast to the general phosphorus compounds utilized and metabolized by microorganisms. Here phosphorus is found as phosphoric acid or phosphate ion, phosphoric acid esters, or phosphoric acid anhydrides. The latter compounds contain phosphorus that is bound only to oxygen. Hydrolytic, oxidative, and radical-based mechanisms for carbon-phosphorus bond cleavage have been described. This review deals with the radical-based mechanism employed by the carbon-phosphorus lyase of the carbon-phosphorus lyase pathway, which involves reactions for activation of phosphonate, carbon-phosphorus bond cleavage, and further chemical transformation before a useful phosphate ion is generated in a series of seven or eight enzyme-catalyzed reactions. The phn genes, encoding the enzymes for this pathway, are widespread among bacterial species. The processes are described with emphasis on glyphosate as a substrate. Additionally, the catabolism of glyphosate is intimately connected with that of aminomethylphosphonate, which is also treated in this review. Results of physiological and genetic analyses are combined with those of bioinformatics analyses. PMID:24600043

Alleviation of carbon catabolite repression in Enterobacter aerogenes for efficient utilization of sugarcane molasses for 2,3-butanediol production.

PubMed

Jung, Moo-Young; Jung, Hwi-Min; Lee, Jinwon; Oh, Min-Kyu

2015-01-01

Due to its cost-effectiveness and rich sugar composition, sugarcane molasses is considered to be a promising carbon source for biorefinery. However, the sugar mixture in sugarcane molasses is not consumed as efficiently as glucose in microbial fermentation due to complex interactions among their utilizing pathways, such as carbon catabolite repression (CCR). In this study, 2,3-butanediol-producing Enterobacter aerogenes was engineered to alleviate CCR and improve sugar utilization by modulating its carbon preference. The gene encoding catabolite repressor/activator (Cra) was deleted in the genome of E. aerogenes to increase the fructose consumption rate. However, the deletion mutation repressed sucrose utilization, resulting in the accumulation of sucrose in the fermentation medium. Cra regulation on expression of the scrAB operon involved in sucrose catabolism was verified by reverse transcription and real-time PCR, and the efficiency of sucrose utilization was restored by disrupting the scrR gene and overexpressing the scrAB operon. In addition, overexpression of the ptsG gene involved in glucose utilization enhanced the glucose preference among mixed sugars, which relieved glucose accumulation in fed-batch fermentation. In fed-batch fermentation using sugarcane molasses, the maximum titer of 2,3-butanediol production by the mutant reached 140.0 g/L at 54 h, which was by far the highest titer of 2,3-butanediol with E. aerogenes achieved through genetic engineering. We have developed genetically engineered E. aerogenes as a 2,3-butanediol producer that efficiently utilizes sugarcane molasses. The fermentation efficiency was dramatically improved by the alleviation of CCR and modulation of carbon preference. These results offer a metabolic engineering approach for achieving highly efficient utilization of mixed sugars for the biorefinery industry.

Carbon Nanotube Electron Gun

NASA Technical Reports Server (NTRS)

Ribaya, Bryan P. (Inventor); Nguyen, Cattien V. (Inventor)

2013-01-01

An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

Carbon nanotube electron gun

NASA Technical Reports Server (NTRS)

Nguyen, Cattien V. (Inventor); Ribaya, Bryan P. (Inventor)

2010-01-01

An electron gun, an electron source for an electron gun, an extractor for an electron gun, and a respective method for producing the electron gun, the electron source and the extractor are disclosed. Embodiments provide an electron source utilizing a carbon nanotube (CNT) bonded to a substrate for increased stability, reliability, and durability. An extractor with an aperture in a conductive material is used to extract electrons from the electron source, where the aperture may substantially align with the CNT of the electron source when the extractor and electron source are mated to form the electron gun. The electron source and extractor may have alignment features for aligning the electron source and the extractor, thereby bringing the aperture and CNT into substantial alignment when assembled. The alignment features may provide and maintain this alignment during operation to improve the field emission characteristics and overall system stability of the electron gun.

Methanol Expression Regulator 1 (Mxr1p) Is Essential for the Utilization of Amino Acids as the Sole Source of Carbon by the Methylotrophic Yeast, Pichia pastoris.

PubMed

Sahu, Umakant; Rangarajan, Pundi N

2016-09-23

Unlike Saccharomyces cerevisiae, the methylotrophic yeast Pichia pastoris can assimilate amino acids as the sole source of carbon and nitrogen. It can grow in media containing yeast extract and peptone (YP), yeast nitrogen base (YNB) + glutamate (YNB + Glu), or YNB + aspartate (YNB + Asp). Methanol expression regulator 1 (Mxr1p), a zinc finger transcription factor, is essential for growth in these media. Mxr1p regulates the expression of several genes involved in the utilization of amino acids as the sole source of carbon and nitrogen. These include the following: (i) GDH2 encoding NAD-dependent glutamate dehydrogenase; (ii) AAT1 and AAT2 encoding mitochondrial and cytosolic aspartate aminotransferases, respectively; (iii) MDH1 and MDH2 encoding mitochondrial and cytosolic malate dehydrogenases, respectively; and (iv) GLN1 encoding glutamine synthetase. Synthesis of all these enzymes is regulated by Mxr1p at the level of transcription except GDH2, whose synthesis is regulated at the level of translation. Mxr1p activates the transcription of AAT1, AAT2, and GLN1 in cells cultured in YP as well as in YNB + Glu media, whereas transcription of MDH1 and MDH2 is activated in cells cultured in YNB + Glu but not in YP. A truncated Mxr1p composed of 400 N-terminal amino acids activates transcription of target genes in cells cultured in YP but not in YNB + Glu. Mxr1p binds to Mxr1p response elements present in the promoters of AAT2, MDH2, and GLN1 We conclude that Mxr1p is essential for utilization of amino acids as the sole source of carbon and nitrogen, and it is a global regulator of multiple metabolic pathways in P. pastoris. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Hydrogeologic and geospatial data for the assesment of focused recharge to the Carbonate-Rock Aquifer in Genesee County, New York

USGS Publications Warehouse

Reddy, James E.; Kappel, William M.

2010-01-01

Existing hydrogeologic and geospatial data useful for the assessment of focused recharge to the carbonate-rock aquifer in the central part of Genesee County, NY, were compiled from numerous local, State, and Federal agency sources. Data sources utilized in this pilot study include available geospatial datasets from Federal and State agencies, interviews with local highway departments and the Genesee County Soil and Water Conservation District, and an initial assessment of karst features through the analysis of ortho-photographs, with minimal field verification. The compiled information is presented in a series of county-wide and quadrangle maps. The county-wide maps present generalized hydrogeologic conditions including distribution of geologic units, major faults, and karst features, and bedrock-surface and water-table configurations. Ten sets of quadrangle maps of the area that overlies the carbonate-rock aquifer present more detailed and additional information including distribution of bedrock outcrops, thin and (or) permeable soils, and karst features such as sinkholes and swallets. Water-resource managers can utilize the information summarized in this report as a guide to their assessment of focused recharge to, and the potential for surface contaminants to reach the carbonate-rock aquifer.

Carbon spectrum utilization by an indigenous strain of Pseudomonas aeruginosa NCIM 5514: Production, characterization and surface active properties of biosurfactant.

PubMed

Varjani, Sunita J; Upasani, Vivek N

2016-12-01

The present research work was undertaken with a mandate to study carbon spectrum utilization and structural characterization of biosurfactant produced by indigenous Pseudomonas aeruginosa NCIM 5514, which showed unique properties to utilize a large number of carbon sources effectively for production of biosurfactant, although glucose was the best carbon substrate. In Bushnell-Hass medium supplemented with glucose (1%, w/v), 3.178±0.071g/l biosurfactant was produced by this isolate in 96h. The biosurfactant produced showed surface tension and emulsification activity values from 29.14±0.05 to 62.29±0.13mN/m and 88.50±1.96 to 15.40±0.91%, respectively. Toluene showed highest emulsification activity followed by kerosene. However, kerosene exhibited emulsion stability for 30days. Biosurfactant was characterized as a mixture of di-rhamnolipid (Rha-Rha-C 10 -C 14:1 ) and mono-rhamnolipid (Rha-C 8 -C 10 ) by FTIR, ESI-MS and LC-MS techniques. High biosurfactant yield opens up doors for the isolate to find utility in various industries. Copyright © 2016 Elsevier Ltd. All rights reserved.

The flexible feedstock concept in Industrial Biotechnology: Metabolic engineering of Escherichia coli, Corynebacterium glutamicum, Pseudomonas, Bacillus and yeast strains for access to alternative carbon sources.

PubMed

Wendisch, Volker F; Brito, Luciana Fernandes; Gil Lopez, Marina; Hennig, Guido; Pfeifenschneider, Johannes; Sgobba, Elvira; Veldmann, Kareen H

2016-09-20

Most biotechnological processes are based on glucose that is either present in molasses or generated from starch by enzymatic hydrolysis. At the very high, million-ton scale production volumes, for instance for fermentative production of the biofuel ethanol or of commodity chemicals such as organic acids and amino acids, competing uses of carbon sources e.g. in human and animal nutrition have to be taken into account. Thus, the biotechnological production hosts E. coli, C. glutamicum, pseudomonads, bacilli and Baker's yeast used in these large scale processes have been engineered for efficient utilization of alternative carbon sources. This flexible feedstock concept is central to the use of non-glucose second and third generation feedstocks in the emerging bioeconomy. The metabolic engineering efforts to broaden the substrate scope of E. coli, C. glutamicum, pseudomonads, B. subtilis and yeasts to include non-native carbon sources will be reviewed. Strategies to enable simultaneous consumption of mixtures of native and non-native carbon sources present in biomass hydrolysates will be summarized and a perspective on how to further increase feedstock flexibility for the realization of biorefinery processes will be given. Copyright © 2016 Elsevier B.V. All rights reserved.

Production of carbon-13-labeled cadaverine by engineered Corynebacterium glutamicum using carbon-13-labeled methanol as co-substrate.

PubMed

Leßmeier, Lennart; Pfeifenschneider, Johannes; Carnicer, Marc; Heux, Stephanie; Portais, Jean-Charles; Wendisch, Volker F

2015-12-01

Methanol, a one-carbon compound, can be utilized by a variety of bacteria and other organisms as carbon and energy source and is regarded as a promising substrate for biotechnological production. In this study, a strain of non-methylotrophic Corynebacterium glutamicum, which was able to produce the polyamide building block cadaverine as non-native product, was engineered for co-utilization of methanol. Expression of the gene encoding NAD+-dependent methanol dehydrogenase (Mdh) from the natural methylotroph Bacillus methanolicus increased methanol oxidation. Deletion of the endogenous aldehyde dehydrogenase genes ald and fadH prevented methanol oxidation to carbon dioxide and formaldehyde detoxification via the linear formaldehyde dissimilation pathway. Heterologous expression of genes for the key enzymes hexulose-6-phosphate synthase and 6-phospho-3-hexuloisomerase of the ribulose monophosphate (RuMP) pathway in this strain restored growth in the presence of methanol or formaldehyde, which suggested efficient formaldehyde detoxification involving RuMP key enzymes. While growth with methanol as sole carbon source was not observed, the fate of 13C-methanol added as co-substrate to sugars was followed and the isotopologue distribution indicated incorporation into central metabolites and in vivo activity of the RuMP pathway. In addition, 13C-label from methanol was traced to the secreted product cadaverine. Thus, this synthetic biology approach led to a C. glutamicum strain that converted the non-natural carbon substrate methanol at least partially to the non-native product cadaverine.

Carbon Nanotube Fiber Ionization Mass Spectrometry: A Fundamental Study of a Multi-Walled Carbon Nanotube Functionalized Corona Discharge Pin for Polycyclic Aromatic Hydrocarbons Analysis.

PubMed

Nahan, Keaton S; Alvarez, Noe; Shanov, Vesselin; Vonderheide, Anne

2017-11-01

Mass spectrometry continues to tackle many complicated tasks, and ongoing research seeks to simplify its instrumentation as well as sampling. The desorption electrospray ionization (DESI) source was the first ambient ionization source to function without extensive gas requirements and chromatography. Electrospray techniques generally have low efficiency for ionization of nonpolar analytes and some researchers have resorted to methods such as direct analysis in real time (DART) or desorption atmospheric pressure chemical ionization (DAPCI) for their analysis. In this work, a carbon nanotube fiber ionization (nanoCFI) source was developed and was found to be capable of solid phase microextraction (SPME) of nonpolar analytes as well as ionization and sampling similar to that of direct probe atmospheric pressure chemical ionization (DP-APCI). Conductivity and adsorption were maintained by utilizing a corona pin functionalized with a multi-walled carbon nanotube (MWCNT) thread. Quantitative work with the nanoCFI source with a designed corona discharge pin insert demonstrated linearity up to 0.97 (R 2 ) of three target PAHs with phenanthrene internal standard. Graphical Abstract ᅟ.

Carbon Nanotube Fiber Ionization Mass Spectrometry: A Fundamental Study of a Multi-Walled Carbon Nanotube Functionalized Corona Discharge Pin for Polycyclic Aromatic Hydrocarbons Analysis

NASA Astrophysics Data System (ADS)

Nahan, Keaton S.; Alvarez, Noe; Shanov, Vesselin; Vonderheide, Anne

2017-09-01

Mass spectrometry continues to tackle many complicated tasks, and ongoing research seeks to simplify its instrumentation as well as sampling. The desorption electrospray ionization (DESI) source was the first ambient ionization source to function without extensive gas requirements and chromatography. Electrospray techniques generally have low efficiency for ionization of nonpolar analytes and some researchers have resorted to methods such as direct analysis in real time (DART) or desorption atmospheric pressure chemical ionization (DAPCI) for their analysis. In this work, a carbon nanotube fiber ionization (nanoCFI) source was developed and was found to be capable of solid phase microextraction (SPME) of nonpolar analytes as well as ionization and sampling similar to that of direct probe atmospheric pressure chemical ionization (DP-APCI). Conductivity and adsorption were maintained by utilizing a corona pin functionalized with a multi-walled carbon nanotube (MWCNT) thread. Quantitative work with the nanoCFI source with a designed corona discharge pin insert demonstrated linearity up to 0.97 (R2) of three target PAHs with phenanthrene internal standard. [Figure not available: see fulltext.

LIQUID BIO-FUEL PRODUCTION FROM NON-FOOD BIOMASS VIA HIGH TEMPERATURE STEAM ELECTROLYSIS

DOE Office of Scientific and Technical Information (OSTI.GOV)

G. L. Hawkes; J. E. O'Brien; M. G. McKellar

2011-11-01

Bio-Syntrolysis is a hybrid energy process that enables production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), bio-syntrolysis has the potential to provide a significant alternative petroleum source that could reduce US dependence on imported oil. Combining hydrogen from HTSE with CO from an oxygen-blown biomass gasifier yields syngas to be used as a feedstock for synthesis of liquid transportation fuels via a Fischer-Tropsch process. Conversion of syngas to liquid hydrocarbon fuels, using a biomass-based carbon source, expandsmore » the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-blown biomass gasifier. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon monoxide and hydrogen). Assuming the thermal efficiency of the power cycle for electricity generation is 50%, (as expected from GEN IV nuclear reactors), the syngas production efficiency ranges from 70% to 73% as the gasifier temperature decreases from 1900 K to 1500 K. Parametric studies of system pressure, biomass moisture content and low temperature alkaline electrolysis are also presented.« less

The effect of toxic carbon source on the reaction of activated sludge in the batch reactor.

PubMed

Wu, Changyong; Zhou, Yuexi; Zhang, Siyu; Xu, Min; Song, Jiamei

2018-03-01

The toxic carbon source can cause higher residual effluent dissolved organic carbon than easily biodegraded carbon source in activated sludge process. In this study, an integrated activated sludge model is developed as the tool to understand the mechanism of toxic carbon source (phenol) on the reaction, regarding the carbon flows during the aeration period in the batch reactor. To estimate the toxic function of phenol, the microbial cells death rate (k death ) is introduced into the model. The integrated model was calibrated and validated by the experimental data and it was found the model simulations matched the all experimental measurements. In the steady state, the toxicity of phenol can result in higher microbial cells death rate (0.1637 h -1 vs 0.0028 h -1 ) and decay rate coefficient of biomass (0.0115 h -1 vs 0.0107 h -1 ) than acetate. In addition, the utilization-associated products (UAP) and extracellular polymeric substances (EPS) formation coefficients of phenol are higher than that of acetate, indicating that more carbon flows into the extracellular components, such as soluble microbial products (SMP), when degrading toxic organics. In the non-steady state of feeding phenol, the yield coefficient for growth and maximum specific growth rate are very low in the first few days (1-10 d), while the decay rate coefficient of biomass and microbial cells death rate are relatively high. The model provides insights into the difference of the dynamic reaction with different carbon sources in the batch reactor. Copyright © 2017 Elsevier Ltd. All rights reserved.

A Novel High-Affinity Sucrose Transporter Is Required for Virulence of the Plant Pathogen Ustilago maydis

PubMed Central

Goos, Sarah; Kämper, Jörg; Sauer, Norbert

2010-01-01

Plant pathogenic fungi cause massive yield losses and affect both quality and safety of food and feed produced from infected plants. The main objective of plant pathogenic fungi is to get access to the organic carbon sources of their carbon-autotrophic hosts. However, the chemical nature of the carbon source(s) and the mode of uptake are largely unknown. Here, we present a novel, plasma membrane-localized sucrose transporter (Srt1) from the corn smut fungus Ustilago maydis and its characterization as a fungal virulence factor. Srt1 has an unusually high substrate affinity, is absolutely sucrose specific, and allows the direct utilization of sucrose at the plant/fungal interface without extracellular hydrolysis and, thus, without the production of extracellular monosaccharides known to elicit plant immune responses. srt1 is expressed exclusively during infection, and its deletion strongly reduces fungal virulence. This emphasizes the central role of this protein both for efficient carbon supply and for avoidance of apoplastic signals potentially recognized by the host. PMID:20161717

Carbon catabolite regulation in Streptomyces: new insights and lessons learned.

PubMed

Romero-Rodríguez, Alba; Rocha, Diana; Ruiz-Villafán, Beatriz; Guzmán-Trampe, Silvia; Maldonado-Carmona, Nidia; Vázquez-Hernández, Melissa; Zelarayán, Augusto; Rodríguez-Sanoja, Romina; Sánchez, Sergio

2017-09-01

One of the most significant control mechanisms of the physiological processes in the genus Streptomyces is carbon catabolite repression (CCR). This mechanism controls the expression of genes involved in the uptake and utilization of alternative carbon sources in Streptomyces and is mostly independent of the phosphoenolpyruvate phosphotransferase system (PTS). CCR also affects morphological differentiation and the synthesis of secondary metabolites, although not all secondary metabolite genes are equally sensitive to the control by the carbon source. Even when the outcome effect of CCR in bacteria is the same, their essential mechanisms can be rather different. Although usually, glucose elicits this phenomenon, other rapidly metabolized carbon sources can also cause CCR. Multiple efforts have been put through to the understanding of the mechanism of CCR in this genus. However, a reasonable mechanism to explain the nature of this process in Streptomyces does not yet exist. Several examples of primary and secondary metabolites subject to CCR will be examined in this review. Additionally, recent advances in the metabolites and protein factors involved in the Streptomyces CCR, as well as their mechanisms will be described and discussed in this review.

Metabolomic and Proteomic Insights into Carbaryl Catabolism by Burkholderia sp. C3 and Degradation of Ten N-Methylcarbamates

PubMed Central

Seo, Jong-Su; Keum, Young-Soo; Li, Qing X.

2013-01-01

Burkholderia sp. C3, an efficient polycyclic aromatic hydrocarbon (PAH) degrader, can utilize 9 of the 10 N-methylcarbamate insecticides including carbaryl as a sole source of carbon. Rapid hydrolysis of carbaryl in C3 is followed by slow catabolism of the resulting 1-naphthol. This study focused on metabolomes and proteomes in C3 cells utilizing carbaryl in comparison to those using glucose or nutrient broth. Sixty of the 867 detected proteins were involved in primary metabolism, adaptive sensing and regulation, transport, stress response, and detoxification. Among the 41 proteins expressed in response to carbaryl were formate dehydrogenase, aldehyde-alcohol dehydrogenase and ethanolamine utilization protein involved in one carbon metabolism. Acetate kinase and phasin were 2 of the 19 proteins that were not detected in carbaryl-supported C3 cells, but detected in glucose-supported C3 cells. Down-production of phasin and polyhydroxyalkanoates in carbaryl-supported C3 cells suggests insufficient carbon sources and lower levels of primary metabolites to maintain an ordinary level of metabolism. Differential metabolomes (approximately 196 identified polar metabolites) showed up-production of metabolites in pentose phosphate pathways and metabolisms of cysteine, cystine and some other amino acids, disaccharides and nicotinate, in contract to down-production of most of the other amino acids and hexoses. The proteomic and metabolomic analyses showed that carbaryl-supported C3 cells experienced strong toxic effects, oxidative stresses, DNA/RNA damages and carbon nutrient deficiency. PMID:23463356

Glyphosate catabolism by Pseudomonas sp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shinabarger, D.L.

1986-01-01

The pathway for the degradation of glyphosate (N-phosphonomethylglycine) by Pseudomonas sp. PG2982 has been determined using metabolic radiolabeling experiments. Radiorespirometry experiments utilizing (3-/sup 14/C) glyphosate revealed that approximately 50-59% of the C3 carbon was oxidized to CO/sub 2/. Fractionation of stationary phase cells labeled with (3-/sup 14/C)glyphosate revealed that from 45-47% of the assimilated C3 carbon is distributed to proteins and that amino acids methionine and serine are highly labeled. The nucleic acid bases adenine and guanine received 90% of the C3 label that was incorporated into nucleic acids, and the only pyrimidine base labeled was thymine. Pulse labeling ofmore » PG2982 cells with (3-/sup 14/C)glyphosate revealed that (3-/sup 14/C)sarcosine is an intermediate in glyphosate degradation. Examination of crude extracts prepared from PG2982 cells revealed the presence of an enzyme that oxidizes sarcosine to glycine and formaldehyde. These results indicate that the first step in glyphosate degradation by PG2982 is cleavage of the carbon-phosphorus bond, resulting in the release of sarcosine and a phosphate group. The phosphate group is utilized as a source of phosphorus, and the sarcosine is degraded to glycine and formaldehyde. Phosphonate utilization by Pseudomonas sp. PG2982 was investigated. Each of the ten phosphonates tested were utilized as a sole source of phosphorus by PG2982. Representative compounds tested included alkylphosphonates, 1-amino-substituted alkylphosphonates, amino-terminal phosphonates, and an arylphosphonate. PG2982 cultures degraded phenylphosphonate to benzene and produced methane from methylphosphonate. The data indicate that PG2982 is capable of cleaving the carbon-phosphorus bond of several structurally different phosphonates.« less

Photoluminescence study of carbon dots from ginger and galangal herbs using microwave technique

NASA Astrophysics Data System (ADS)

Isnaeni; Rahmawati, I.; Intan, R.; Zakaria, M.

2018-03-01

Carbon dots are new type of fluorescent nanoparticle that can be synthesis easily from natural sources. We have synthesized carbon dots from ginger and galangal herbs using microwave technique and studied their optical properties. We synthesized colloidal carbon dots in water solvent by varying microwave processing time. UV-Vis absorbance, photoluminescence, time-resolved photoluminescence, and transmission electron microscope were utilized to study properties of carbon dots. We found that microwave processing time significantly affect optical properties of synthesized carbon dots. UV-Vis absorbance spectra and time-resolved photoluminescence results show that luminescent of carbon dots is dominated by recombination process from n-π* surface energy level. With further development, these carbon dots are potential for several applications.

[Carbon sources metabolic characteristics of airborne microbial communities in constructed wetlands].

PubMed

Song, Zhi-Wen; Wang, Lin; Xu, Ai-Ling; Wu, Deng-Deng; Xia, Yan

2015-02-01

Using BIOLOG-GN plates, this article describes the carbon sources metabolic characteristics of airborne microbial communities in a free surface-flow constructed wetland in different seasons and clarify the correlation between airborne microbial metabolic functions and environmental factors. The average well color development (AWCD), carbon metabolic profiles and McIntosh values of airborne microbial communities in different seasons were quite different. Analysis of the variations showed that AWCD in spring and summer differed significantly from that in autumn and winter (P < 0.01). In the same season, the degree of utilization of different types of carbon by airborne microbes was different. Summer had a significant difference from other seasons (P < 0.05). Dominant communities of airborne microbes in four seasons were carboxylic acids metabolic community, carbohydrates metabolic community, polymers metabolic community and carboxylic acids metabolic community respectively. Principal component analysis showed that the carbon metabolic characteristics of airborne microbial community in autumn were similar to those in winter but different from those in spring and summer. The characteristics of carbon metabolism revealed differences between summer and spring, autumn, or winter. These differences were mainly caused by amines or amides while the differences between spring and autumn or winter were mainly caused by carboxylic acids. Environmental factors, including changes in wind speed, temperature, and humidity acted to influence the carbon sources metabolic properties of airborne microbial community. The dominant environmental factors that acted to influence the carbon sources metabolic properties of airborne microbial community varied between different seasons.

The radiocarbon signature of microorganisms in the mesopelagic ocean.

PubMed

Hansman, Roberta L; Griffin, Sheila; Watson, Jordan T; Druffel, Ellen R M; Ingalls, Anitra E; Pearson, Ann; Aluwihare, Lihini I

2009-04-21

Several lines of evidence indicate that microorganisms in the meso- and bathypelagic ocean are metabolically active and respiring carbon. In addition, growing evidence suggests that archaea are fixing inorganic carbon in this environment. However, direct quantification of the contribution from deep ocean carbon sources to community production in the dark ocean remains a challenge. In this study, carbon flow through the microbial community at 2 depths in the mesopelagic zone of the North Pacific Subtropical Gyre was examined by exploiting the unique radiocarbon signatures (Delta(14)C) of the 3 major carbon sources in this environment. The radiocarbon content of nucleic acids, a biomarker for viable cells, isolated from size-fractionated particles (0.2-0.5 microm and >0.5 microm) showed the direct incorporation of carbon delivered by rapidly sinking particles. Most significantly, at the 2 mesopelagic depths examined (670 m and 915 m), carbon derived from in situ autotrophic fixation supported a significant fraction of the free-living microbial community (0.2-0.5 microm size fraction), but the contribution of chemoautotrophy varied markedly between the 2 depths. Results further showed that utilization of the ocean's largest reduced carbon reservoir, (14)C-depleted, dissolved organic carbon, was negligible in this environment. This isotopic portrait of carbon assimilation by the in situ, free-living microbial community, integrated over >50,000 L of seawater, implies that recent, photosynthetic carbon is not always the major carbon source supporting microbial community production in the mesopelagic realm.

Duckweed diversity decreases heavy metal toxicity by altering the metabolic function of associated microbial communities.

PubMed

Zhao, Zhao; Shi, Huijuan; Liu, Cunqi; Kang, Xianjiang; Chen, Lingci; Liang, Xiaofei; Jin, Lei

2018-07-01

Mono-cultured and mix-cultured duckweed species were investigated with respect to the function of their associated microbial communities in heavy metal contaminated wastewater. Results show that the carbon source utilization patterns of the L. aequinoctialis- and S. polyrhiza-associated microbial communities were different. The relationships between microbial activity, antioxidant enzyme activity (CAT, GSH, and SOD) and growth was positive and significant. The microbial activity of L. aequinoctialis and S. polyrhiza in mixture was higher than in monoculture in low and high heavy metal, respectively, thereby altering the utilization of specific carbon source types and increasing duckweed growth and antioxidant enzyme activity, when compared to the monocultured duckweed. Furthermore, results indicate that duckweed species in mixture are protected from damage through regulation of the associated bacterial communities. Copyright © 2018 Elsevier Ltd. All rights reserved.

Involvement of Two Plasmids in the Degradation of Carbaryl by Arthrobacter sp. Strain RC100

PubMed Central

Hayatsu, Masahito; Hirano, Motoko; Nagata, Tadahiro

1999-01-01

A bacterium capable of utilizing carbaryl (1-naphthyl N-methylcarbamate) as the sole carbon source was isolated from carbaryl-treated soil. This bacterium was characterized taxonomically as Arthrobacter and was designated strain RC100. RC100 hydrolyzes the N-methylcarbamate linkage to 1-naphthol, which was further metabolized via salicylate and gentisate. Strain RC100 harbored three plasmids (designated pRC1, pRC2, and pRC3). Mutants unable to degrade carbaryl arose at a high frequency after treating the culture with mitomycin C. All carbaryl-hydrolysis-deficient mutants (Cah−) lacked pRC1, and all 1-naphthol-utilization-deficient mutants (Nat−) lacked pRC2. The plasmid-free strain RC107 grew on gentisate as a carbon source. These two plasmids could be transferred to Cah− mutants or Nat− mutants by conjugation, resulting in the restoration of the Cah and Nah phenotypes. PMID:10049857

Microbial Degradation of Isopropyl-N-3-Chlorophenylcarbamate and 2-Chloroethyl-N-3-Chlorophenylcarbamate

PubMed Central

Kaufman, D. D.; Kearney, P. C.

1965-01-01

Microbial degradation of isopropyl-N-3-chlorophenylcarbamate (CIPC) and 2-chloroethyl-N-3-chlorophenylcarbamate (CEPC) was observed in a soil perfusion system. Degradation in perfused soils, and by pure cultures of effective bacterial isolates, was demonstrated by the production of 3-chloroaniline and the subsequent liberation of free chloride ion. Identified isolates effective in degrading and utilizing CIPC as a sole source of carbon included Pseudomonas striata Chester, a Flavobacterium sp., an Agrobacterium sp., and an Achromobacter sp. Identified isolates, effective in degrading and utilizing CEPC as a sole source of carbon, included an Achromobacter sp. and an Arthrobacter sp. CIPC-effective isolates degraded CEPC more slowly than CIPC, whereas CEPC-effective isolates degraded CIPC more rapidly than CEPC. Both CIPC- and CEPC-effective isolates degraded isopropyl N-phenylcarbamate (IPC) more rapidly than either CIPC or CEPC. Images Fig. 3 PMID:14325285

Physiological-biochemical properties and the ability to synthesize polyhydroxyalkanoates of the glucose-utilizing strain of the hydrogen bacterium Ralstonia eutropha B8562.

PubMed

Volova, T G; Trusova, M Y; Kalacheva, G S; Kozhevnicov, I V

2006-11-01

Physiological-biochemical, genetic, and cultural properties of the glucose-utilizing mutant strain Ralstonia eutropha B8562 have been compared with those of its parent strain R. eutropha B5786. It has been shown that growth characteristics of the strain cultured on glucose as the sole carbon and energy source are comparable with those of the parent strain. Strain B8562 is characterized by high polyhydroxyalkanoate (PHA) yields on different carbon sources (CO(2), fructose, and glucose). PHA accumulation in the strain batch cultured on glucose under nitrogen deficiency reaches 90 %. The major monomer in the PHA is beta-hydroxybutyric acid (more than 99 mol %); the identified minor components are beta-hydroxyvaleric acid (0.25-0.72 mol %) and beta-hydroxyhexanoic acid (0.08-1.5 mol %). The strain is a promising PHA producer on available sugar-containing media with glucose.

Characteristics of Ampel bamboo as a biomass energy source potential in Bali

NASA Astrophysics Data System (ADS)

Sucipta, M.; Putra Negara, D. N. K.; Tirta Nindhia, T. G.; Surata, I. W.

2017-05-01

Currently, non-renewable fossil energy dominates utilization of the world energy need for many applications. Efforts has been developed to find alternative renewable energy sources, due to fossil energy availability is diminishing. And one of renewable energy source is from biomass. The aim of this research is to determine characteristics of the Ampel bamboo (Bambusa vulgaris) as an energy potential of biomass. The Ampel bamboo’s characteristics possessed are evaluated based on its chemical composition; moisture, volatile, ash, and fixed carbon through proximate analysis; and also carbon, hydrogen and nitrogen content through ultimate analysis. From the Thermo-gravimetric analysis (TGA) indicates that Ampel bamboo contains of about 18.10% hemicelluloses, 47.75% cellulose and 18.86% lignin. While from the ultimate analysis results in the content of carbon, hydrogen, and Nitrogen of Ampel bamboo are 39.75%, 5.75% and 0% respectively. With such characteristics, it indicates that Ampel bamboo has an attractive potential as a renewable energy source.

Spray-coated carbon nanotube thin-film transistors with striped transport channels

NASA Astrophysics Data System (ADS)

Jeong, Minho; Lee, Kunhak; Choi, Eunsuk; Kim, Ahsung; Lee, Seung-Beck

2012-12-01

We present results for the transfer characteristics of carbon nanotube thin-film transistors (CNT-TFTs) that utilize single-walled carbon nanotube thin-films prepared by direct spray-coating on the substrate. By varying the number of spray-coatings (Nsp) and the concentration of nanotubes in solution (CNT), it was possible to control the conductivity of the spray-coated nanotube thin-film from 129 to 0.1 kΩ/□. Also, by introducing stripes into the channel of the CNT-TFT, and thereby reducing the number of metallic percolation paths between source and drain, it was possible to enhance the on/off current ratio 1000-fold, from 10 to 104, demonstrating that it may be possible to utilize spray-coating as a method to fabricate CNT-TFTs for large area switching array applications.

SNS Central Helium Liquefier spare Carbon Bed installation and commissioning

NASA Astrophysics Data System (ADS)

DeGraff, B.; Howell, M.; Kim, S.; Neustadt, T.

2017-12-01

The Spallation Neutron Source (SNS) Central Helium Liquefier (CHL) at Oak Ridge National Laboratory (ORNL) has been without major operations downtime since operations were started back in 2006. This system utilizes a vessel filled with activated carbon as the final major component to remove oil vapor from the compressed helium circuit prior to insertion into the system’s cryogenic cold box. The need for a spare carbon bed at SNS due to the variability of carbon media lifetime calculation to adsorption efficiency will be discussed. The fabrication, installation and commissioning of this spare carbon vessel will be presented. The novel plan for connecting the spare carbon vessel piping to the existing infrastructure will be presented.

IDENTITY OF THE PINK-PIGMENTED METHANOL-OXIDIZING BACTERIA AS VIBRIO EXTORQUENS

PubMed Central

Stocks, Peter K.; McCleskey, C. S.

1964-01-01

Stocks, Peter K. (Louisiana State University, Baton Rouge), and C. S. McCleskey. Identity of the pink-pigmented methanol-oxidizing bacteria as Vibrio extorquens. J. Bacteriol. 88:1065–1070. 1964.—Pink-pigmented bacteria isolated from enrichment cultures of methane oxidizers were found to possess similar morphological, cultural, and physiological characteristics. All the strains utilized methanol, formate, oxalate, succinate, glycerol, and benzene as sole carbon sources; methanol, formate, and glycerol afforded best growth. Most strains utilized fructose and ribose; other carbohydrates tested were not available as carbon and energy sources. There was strain variation in the use of hexane, heptane, n-propanol, n-butanol, acetate, and propionate. Methane, ethane, n-propane, and n-butane were not utilized. Our isolates, and Pseudomonas methanica of Harrington and Kallio (not the methane-dependent P. methanica of Dworkin and Foster), Pseudomonas AM1 of Peele and Quayle, Pseudomonas PRL-W4 of Kaneda and Roxburgh, and Protaminobacter ruber den Dooren de Jong are nearly identical with Vibrio extorquens (Bassalik) Bhat and Barker, and should be considered the same species. Images PMID:14219020

IDENTITY OF THE PINK-PIGMENTED METHANOL-OXIDIZING BACTERIA AS VIBRIO EXTORQUENS.

PubMed

STOCKS, P K; MCCLESKEY, C S

1964-10-01

Stocks, Peter K. (Louisiana State University, Baton Rouge), and C. S. McCleskey. Identity of the pink-pigmented methanol-oxidizing bacteria as Vibrio extorquens. J. Bacteriol. 88:1065-1070. 1964.-Pink-pigmented bacteria isolated from enrichment cultures of methane oxidizers were found to possess similar morphological, cultural, and physiological characteristics. All the strains utilized methanol, formate, oxalate, succinate, glycerol, and benzene as sole carbon sources; methanol, formate, and glycerol afforded best growth. Most strains utilized fructose and ribose; other carbohydrates tested were not available as carbon and energy sources. There was strain variation in the use of hexane, heptane, n-propanol, n-butanol, acetate, and propionate. Methane, ethane, n-propane, and n-butane were not utilized. Our isolates, and Pseudomonas methanica of Harrington and Kallio (not the methane-dependent P. methanica of Dworkin and Foster), Pseudomonas AM1 of Peele and Quayle, Pseudomonas PRL-W4 of Kaneda and Roxburgh, and Protaminobacter ruber den Dooren de Jong are nearly identical with Vibrio extorquens (Bassalik) Bhat and Barker, and should be considered the same species.

Preferential Use of Carbon Sources in Culturable Aerobic Mesophilic Bacteria of Coptotermes curvignathus's (Isoptera: Rhinotermitidae) Gut and Its Foraging Area.

PubMed

Wong, W Z; H'ng, P S; Chin, K L; Sajap, Ahmad Said; Tan, G H; Paridah, M T; Othman, Soni; Chai, E W; Go, W Z

2015-10-01

The lower termite, Coptotermes curvignathus, is one of the most prominent plantation pests that feed upon, digest, and receive nourishment from exclusive lignocellulose diets. The objective of this study was to examine the utilization of sole carbon sources by isolated culturable aerobic bacteria among communities from the gut and foraging pathway of C. curvignathus. We study the bacteria occurrence from the gut of C. curvignathus and its surrounding feeding area by comparing the obtained phenotypic fingerprint with Biolog's extensive species library. A total of 24 bacteria have been identified mainly from the family Enterobacteriaceae from the identification of Biolog Gen III. Overall, the bacteria species in the termite gut differ from those of foraging pathway within a location, except Acintobacter baumannii, which was the only bacteria species found in both habitats. Although termites from a different study area do not have the same species of bacteria in the gut, they do have a bacterial community with similar role in degrading certain carbon sources. Sugars were preferential in termite gut isolates, while nitrogen carbon sources were preferential in foraging pathway isolates. The preferential use of specific carbon sources by these two bacterial communities reflects the role of bacteria for regulation of carbon metabolism in the termite gut and foraging pathway. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Adsorbents for capturing mercury in coal-fired boiler flue gas.

PubMed

Yang, Hongqun; Xu, Zhenghe; Fan, Maohong; Bland, Alan E; Judkins, Roddie R

2007-07-19

This paper reviews recent advances in the research and development of sorbents used to capture mercury from coal-fired utility boiler flue gas. Mercury emissions are the source of serious health concerns. Worldwide mercury emissions from human activities are estimated to be 1000 to 6000 t/annum. Mercury emissions from coal-fired power plants are believed to be the largest source of anthropogenic mercury emissions. Mercury emissions from coal-fired utility boilers vary in total amount and speciation, depending on coal types, boiler operating conditions, and configurations of air pollution control devices (APCDs). The APCDs, such as fabric filter (FF) bag house, electrostatic precipitator (ESP), and wet flue gas desulfurization (FGD), can remove some particulate-bound and oxidized forms of mercury. Elemental mercury often escapes from these devices. Activated carbon injection upstream of a particulate control device has been shown to have the best potential to remove both elemental and oxidized mercury from the flue gas. For this paper, NORIT FGD activated carbon was extensively studied for its mercury adsorption behavior. Results from bench-, pilot- and field-scale studies, mercury adsorption by coal chars, and a case of lignite-burned mercury control were reviewed. Studies of brominated carbon, sulfur-impregnated carbon and chloride-impregnated carbon were also reviewed. Carbon substitutes, such as calcium sorbents, petroleum coke, zeolites and fly ash were analyzed for their mercury-adsorption performance. At this time, brominated activated carbon appears to be the best-performing mercury sorbent. A non-injection regenerable sorbent technology is briefly introduced herein, and the issue of mercury leachability is briefly covered. Future research directions are suggested.

Effect of drought on sorbitol and sucrose metabolism in sinks and sources of peach

Treesearch

Riccardo Lo Bianco; Mark Rieger; Shi-Jean S. Sung

2000-01-01

In peach (Prunus persica [L.] Batsch.), sorbitol and sucrose are the two main forms of photosynthetic and translocated carbon and may have different functions depending on the organ of utilization and its developmental stage. The role and interaction of sorbitol and sucrose metabolism was studied in mature leaves (source) and shoot tips (sinks) of...

Interactions of Methylotrophs with Plants and Other Heterotrophic Bacteria

PubMed Central

Iguchi, Hiroyuki; Yurimoto, Hiroya; Sakai, Yasuyoshi

2015-01-01

Methylotrophs, which can utilize methane and/or methanol as sole carbon and energy sources, are key players in the carbon cycle between methane and CO2, the two most important greenhouse gases. This review describes the relationships between methylotrophs and plants, and between methanotrophs (methane-utilizers, a subset of methylotrophs) and heterotrophic bacteria. Some plants emit methane and methanol from their leaves, and provide methylotrophs with habitats. Methanol-utilizing methylotrophs in the genus Methylobacterium are abundant in the phyllosphere and have the ability to promote the growth of some plants. Methanotrophs also inhabit the phyllosphere, and methanotrophs with high methane oxidation activities have been found on aquatic plants. Both plant and environmental factors are involved in shaping the methylotroph community on plants. Methanotrophic activity can be enhanced by heterotrophic bacteria that provide growth factors (e.g., cobalamin). Information regarding the biological interaction of methylotrophs with other organisms will facilitate a better understanding of the carbon cycle that is driven by methylotrophs. PMID:27682083

The Importance of CO2 Utilizing Chemolithoautotrophic Microorganisms for Carbon Sequestration and Isotope Signatures of SOM in Tropical Rainforest Soils

NASA Astrophysics Data System (ADS)

Nowak, M. E.; Behrendt, T.; Quesada, B.; Yanez Serrano, A. M.; Trumbore, S.

2015-12-01

Soil organic matter (SOM) is a major compartment of the tropical carbon cycle with up to 26 % of global carbon stocks stored in tropical soils. Understanding factors and processes driving SOM dynamics under changing climate conditions is crucial for predicting the role of tropical forest ecosystems to act as a carbon sink or source. Soil microorganisms are major drivers of the belowground carbon cycle by releasing CO2 by soil respiration but also by stabilizing and storing SOM, as indicated by recent research. Our investigations focus on chemolithoautotrophic microorganisms, a group that relies on CO2 as their carbon source. Chemolithoautotrophic microorganisms have been shown to be highly abundant in soils, whereas their role in SOM sequestration is still poorly understood. In tropical soils, the activity of chemolithoautotropic microbes might be important for generating and stabilizing carbon, especially in the deeper soil, which is rich in CO2 and reduced energy sources like Fe2+. They further might impact carbon isotope signatures (13C and 14C) of SOM, because of enzymatic fractionation during carboxylation and the use of carbon, which has a distinct isotopic composition than other carbon sources at the same depth. In order to study the activity of chemolithoautotropic microbes and their importance for SOM, we conducted isotope and isotope-labelling studies, gas measurements as well as molecular analyses at soils from the Atto site from 0 to 1 meter depth. These soils are classified as Ferralsols and Alisols and represent the most abundant soil types in the Amazon. With this we will be able to gain knowledge about the function and identity of an important group of microorganisms and their contribution to crucial biogeochemical cycles in the world`s most important ecosystem.

The Molecular Level Characterization of Biodegradable Polymers Originated from Polyethylene Using Non-Oxygenated Polyethylene Wax as a Carbon Source for Polyhydroxyalkanoate Production.

PubMed

Johnston, Brian; Jiang, Guozhan; Hill, David; Adamus, Grazyna; Kwiecień, Iwona; Zięba, Magdalena; Sikorska, Wanda; Green, Matthew; Kowalczuk, Marek; Radecka, Iza

2017-08-28

There is an increasing demand for bio-based polymers that are developed from recycled materials. The production of biodegradable polymers can include bio-technological (utilizing microorganisms or enzymes) or chemical synthesis procedures. This report demonstrates the corroboration of the molecular structure of polyhydroxyalkanoates (PHAs) obtained by the conversion of waste polyethylene (PE) via non-oxygenated PE wax (N-PEW) as an additional carbon source for a bacterial species. The N-PEW, obtained from a PE pyrolysis reaction, has been found to be a beneficial carbon source for PHA production with Cupriavidus necator H16. The production of the N-PEW is an alternative to oxidized polyethylene wax (O-PEW) (that has been used as a carbon source previously) as it is less time consuming to manufacture and offers fewer industrial applications. A range of molecular structural analytical techniques were performed on the PHAs obtained; which included nuclear magnetic resonance (NMR) and electrospray ionisation tandem mass spectrometry (ESI-MS/MS). Our study showed that the PHA formed from N-PEW contained 3-hydroxybutyrate (HB) with 11 mol% of 3-hydroxyvalerate (HV) units.

The Molecular Level Characterization of Biodegradable Polymers Originated from Polyethylene Using Non-Oxygenated Polyethylene Wax as a Carbon Source for Polyhydroxyalkanoate Production

PubMed Central

Johnston, Brian; Jiang, Guozhan; Hill, David; Adamus, Grazyna; Zięba, Magdalena; Sikorska, Wanda; Green, Matthew; Kowalczuk, Marek

2017-01-01

There is an increasing demand for bio-based polymers that are developed from recycled materials. The production of biodegradable polymers can include bio-technological (utilizing microorganisms or enzymes) or chemical synthesis procedures. This report demonstrates the corroboration of the molecular structure of polyhydroxyalkanoates (PHAs) obtained by the conversion of waste polyethylene (PE) via non-oxygenated PE wax (N-PEW) as an additional carbon source for a bacterial species. The N-PEW, obtained from a PE pyrolysis reaction, has been found to be a beneficial carbon source for PHA production with Cupriavidus necator H16. The production of the N-PEW is an alternative to oxidized polyethylene wax (O-PEW) (that has been used as a carbon source previously) as it is less time consuming to manufacture and offers fewer industrial applications. A range of molecular structural analytical techniques were performed on the PHAs obtained; which included nuclear magnetic resonance (NMR) and electrospray ionisation tandem mass spectrometry (ESI-MS/MS). Our study showed that the PHA formed from N-PEW contained 3-hydroxybutyrate (HB) with 11 mol% of 3-hydroxyvalerate (HV) units. PMID:28952552

Atypical ethanol production by carbon catabolite derepressed lactobacilli.

PubMed

Kim, Jae-Han; Block, David E; Shoemaker, Sharon P; Mills, David A

2010-11-01

Cost effective use of lignocellulosic biomass for bio-based chemical production requires the discovery of novel strains and processes. Lactobacillus pentosus JH5XP5 is a carbon catabolite repression negative mutant which utilizes glucose and pentoses derived from lignocellulosic biomass in the media simultaneously. With a broad range of carbon substrates, L. pentosus JH5XP5 produced a significant amount of ethanol without acetate formation. The yields of ethanol were 2.0- to 2.5-fold higher than those of lactate when glucose, galactose or maltose was used either as a single carbon source or simultaneously with glucose. L. pentosus JH5XP5 was successfully used in an integrated process of simultaneous saccharification and mixed sugar fermentation of rice straw hydrolysate. During the fermentation, the enzyme activities for the saccharification of cellulose were not diminished. Moreover glucose, xylose, and arabinose sugars derived from rice straw hyrolysate were consumed concurrently as if a single carbon source existed and no sugars or cellulosic fiber remained after the fermentation.

Economic approach to assess the forest carbon implications of biomass energy.

PubMed

Daigneault, Adam; Sohngen, Brent; Sedjo, Roger

2012-06-05

There is widespread concern that biomass energy policy that promotes forests as a supply source will cause net carbon emissions. Most of the analyses that have been done to date, however, are biological, ignoring the effects of market adaptations through substitution, net imports, and timber investments. This paper uses a dynamic model of forest and land use management to estimate the impact of United States energy policies that emphasize the utilization of forest biomass on global timber production and carbon stocks over the next 50 years. We show that when market factors are included in the analysis, expanded demand for biomass energy increases timber prices and harvests, but reduces net global carbon emissions because higher wood prices lead to new investments in forest stocks. Estimates are sensitive to assumptions about whether harvest residues and new forestland can be used for biomass energy and the demand for biomass. Restricting biomass energy to being sourced only from roundwood on existing forestland can transform the policy from a net sink to a net source of emissions. These results illustrate the importance of capturing market adjustments and a large geographic scope when measuring the carbon implications of biomass energy policies.

Enhancing substrate utilization and power production of a microbial fuel cell with nitrogen-doped carbon aerogel as cathode catalyst.

PubMed

Tardy, Gábor Márk; Lóránt, Bálint; Lóka, Máté; Nagy, Balázs; László, Krisztina

2017-07-01

Catalytic efficiency of a nitrogen-doped, mesoporous carbon aerogel cathode catalyst was investigated in a two-chambered microbial fuel cell (MFC) applying graphite felt as base material for cathode and anode, utilizing peptone as carbon source. This mesoporous carbon aerogel containing catalyst layer on the cathode increased the maximum power density normalized to the anode volume to 2.7 times higher compared to the maximum power density obtained applying graphite felt cathode without the catalyst layer. At high (2 and 3) cathode/anode volume ratios, maximum power density exceeded 40 W m -3 . At the same time, current density and specific substrate utilization rate increased by 58% resulting in 31.9 A m -3 and 18.8 g COD m -3  h -1 , respectively (normalized to anode volume). Besides the increase of the power and the rate of biodegradation, the investigated catalyst decreased the internal resistance from the range of 450-600 to 350-370 Ω. Although Pt/C catalyst proved to be more efficient, a considerable decrease in the material costs might be achieved by substituting it with nitrogen-doped carbon aerogel in MFCs. Such cathode still displays enhanced catalytic effect.

Hydrogen sulfide production by sulfate-reducing bacteria utilizing additives eluted from plastic resins.

PubMed

Tsuchida, Daisuke; Kajihara, Yusuke; Shimidzu, Nobuhiro; Hamamura, Kengo; Nagase, Makoto

2011-06-01

In the present study it was demonstrated that organic additives eluted from plastic resins could be utilized as substrates by sulfate-reducing bacteria. Two laboratory-scale experiments, a microcosm experiment and a leaching experiment, were conducted using polyvinyl chloride (PVC) as a model plastic resin. In the former experiment, the conversion of sulfate to sulfide was evident in microcosms that received plasticized PVC as the sole carbon source, but not in those that received PVC homopolymer. Additionally, dissolved organic carbon accumulated only in microcosms that received plasticized PVC, indicating that the dissolved organic carbon originated from additives. In the leaching experiment, phenol and bisphenol A were found in the leached solutions. These results suggest that the disposal of waste plastics in inert waste landfills may result in the production of H(2)S.

SNS Central Helium Liquefier spare Carbon Bed installation and commissioning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Degraff, Brian D.; Howell, Matthew P.; Kim, Sang-Ho

The Spallation Neutron Source (SNS) Central Helium Liquefier (CHL) at Oak Ridge National Laboratory (ORNL) has been without major operations downtime since operations were started back in 2006. This system utilizes a vessel filled with activated carbon as the final major component to remove oil vapor from the compressed helium circuit prior to insertion into the system's cryogenic cold box. The need for a spare carbon bed at SNS due to the variability of carbon media lifetime calculation to adsorption efficiency will be discussed. The fabrication, installation and commissioning of this spare carbon vessel will be presented. The novel planmore » for connecting the spare carbon vessel piping to the existing infrastructure will be presented.« less

L-arabinose fermenting yeast

DOEpatents

Zhang, Min; Singh, Arjun; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric; Suominen, Pirkko

2010-12-07

An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. Methods of producing ethanol include utilizing these modified yeast strains. ##STR00001##

Nature, nomenclature and taxonomy of obligate methanol utilizing strains.

PubMed

Cercel, M

1999-01-01

In a screening program, a number of different bacterial strains with the ability to utilize methanol as a sole carbon and energy source were isolated and described. They are well known methanol utilizing genera Pseudomonas, Klebsiella, Micrococcus, Methylomonas or, on the contrary, the new, unknown genera and species of methylotrophic bacteria. In the last category, Acinetobacter and Alcaligenes are the new reported genera of organisms able to use methanol as a sole carbon and energy source. The present paper reports the very complex physiological and biochemical modifications when very versatile bacteria such as Pseudomonas aeruginosa and Acinetobacter calcoaceticus are cultured on methanol and when the obligate methylotrophic state is compared with the facultative methylotrophic state of the same bacterial strain. Based on experiments and comparisons with literature data, it seems that Methylomonas methanica is the obligate methylotrophic state of Pseudomonas aeruginosa and that Acinetobacter calcoaceticus is the facultative methylotrophic state of Methylococcus capsulatus, an obligate methylotroph. The relationship of the obligate to the facultative and of the facultative to the obligate methylotrophy were established. These new methylotrophic genera and species, the profound physiological and biochemical modifications as well as the new data concerning nature, nomenclature and taxonomy of methanol utilizing bateria were reported for the first time in 1983.

Miniature ceramic fuel cell

DOEpatents

Lessing, Paul A.; Zuppero, Anthony C.

1997-06-24

A miniature power source assembly capable of providing portable electricity is provided. A preferred embodiment of the power source assembly employing a fuel tank, fuel pump and control, air pump, heat management system, power chamber, power conditioning and power storage. The power chamber utilizes a ceramic fuel cell to produce the electricity. Incoming hydro carbon fuel is automatically reformed within the power chamber. Electrochemical combustion of hydrogen then produces electricity.

Re-assessment of plant carbon dynamics at the Duke free-air CO2 enrichment site: interactions of atmospheric [CO2] with nitrogen and water availability over stand development

Treesearch

Heather R. McCarthy; Ram Oren; Kurt H Johnsen; Anne Gallet-Budynek; Seth G. Pritchard; Charles W Cook; Shannon L. LaDeau; Robert B. Jackson; Adrien C. Finzi

2010-01-01

The potential for elevated [CO2]-induced changes to plant carbon (C) storage, through modifications in plant production and allocation of C among plant pools, is an important source of uncertainty when predicting future forest function. Utilizing 10 yr of data from the Duke free-air CO2 enrichment site, we evaluated the...

Microbial Thiocyanate Utilization under Highly Alkaline Conditions

PubMed Central

Sorokin, Dimitry Y.; Tourova, Tatyana P.; Lysenko, Anatoly M.; Kuenen, J. Gijs

2001-01-01

Three kinds of alkaliphilic bacteria able to utilize thiocyanate (CNS−) at pH 10 were found in highly alkaline soda lake sediments and soda soils. The first group included obligate heterotrophs that utilized thiocyanate as a nitrogen source while growing at pH 10 with acetate as carbon and energy sources. Most of the heterotrophic strains were able to oxidize sulfide and thiosulfate to tetrathionate. The second group included obligately autotrophic sulfur-oxidizing alkaliphiles which utilized thiocyanate nitrogen during growth with thiosulfate as the energy source. Genetic analysis demonstrated that both the heterotrophic and autotrophic alkaliphiles that utilized thiocyanate as a nitrogen source were related to the previously described sulfur-oxidizing alkaliphiles belonging to the gamma subdivision of the division Proteobacteria (the Halomonas group for the heterotrophs and the genus Thioalkalivibrio for autotrophs). The third group included obligately autotrophic sulfur-oxidizing alkaliphilic bacteria able to utilize thiocyanate as a sole source of energy. These bacteria could be enriched on mineral medium with thiocyanate at pH 10. Growth with thiocyanate was usually much slower than growth with thiosulfate, although the biomass yield on thiocyanate was higher. Of the four strains isolated, the three vibrio-shaped strains were genetically closely related to the previously described sulfur-oxidizing alkaliphiles belonging to the genus Thioalkalivibrio. The rod-shaped isolate differed from the other isolates by its ability to accumulate large amounts of elemental sulfur inside its cells and by its ability to oxidize carbon disulfide. Despite its low DNA homology with and substantial phenotypic differences from the vibrio-shaped strains, this isolate also belonged to the genus Thioalkalivibrio according to a phylogenetic analysis. The heterotrophic and autotrophic alkaliphiles that grew with thiocyanate as an N source possessed a relatively high level of cyanase activity which converted cyanate (CNO−) to ammonia and CO2. On the other hand, cyanase activity either was absent or was present at very low levels in the autotrophic strains grown on thiocyanate as the sole energy and N source. As a result, large amounts of cyanate were found to accumulate in the media during utilization of thiocyanate at pH 10 in batch and thiocyanate-limited continuous cultures. This is a first direct proof of a “cyanate pathway” in pure cultures of thiocyanate-degrading bacteria. Since it is relatively stable under alkaline conditions, cyanate is likely to play a role as an N buffer that keeps the alkaliphilic bacteria safe from inhibition by free ammonia, which otherwise would reach toxic levels during dissimilatory degradation of thiocyanate. PMID:11157213

Terahertz science and technology of carbon nanomaterials.

PubMed

Hartmann, R R; Kono, J; Portnoi, M E

2014-08-15

The diverse applications of terahertz (THz) radiation and its importance to fundamental science makes finding ways to generate, manipulate and detect THz radiation one of the key areas of modern applied physics. One approach is to utilize carbon nanomaterials, in particular, single-wall carbon nanotubes and graphene. Their novel optical and electronic properties offer much promise to the field of THz science and technology. This article describes the past, current, and future of THz science and technology of carbon nanotubes and graphene. We will review fundamental studies such as THz dynamic conductivity, THz nonlinearities and ultrafast carrier dynamics as well as THz applications such as THz sources, detectors, modulators, antennas and polarizers.

Production of copolymer, poly (hydroxybutyrate-co-hydroxyvalerate) by Halomonas campisalis MCM B-1027 using agro-wastes.

PubMed

Kulkarni, S O; Kanekar, P P; Jog, J P; Sarnaik, S S; Nilegaonkar, S S

2015-01-01

For cost effective production of PHA, agro-wastes like fruit peels, bagasse and deoiled cakes were screened as a sole source of carbon. Halomonas campisalis MCM B-1027, which was isolated from one of the extreme environment, i.e. Lonar Lake, India, was explored for the production of PHA using fruit peels and bagasse having fermentable sugars. Among the agro-wastes tested, 1% (v/v) aqueous extract of bagasse was found to be the optimum carbon source with 47% PHA production on dry cell weight basis. Significant amount of total sugars are utilized and converted into cell mass and PHA, e.g. 62% sugar utilized from bagasse extract, 84% from orange peel extract and 71% from banana peel extract as compared to 51% in case of maltose. Hence the cost of production would be positively reduced. The detailed characterization of PHA formed by H. campisalis using bagasse extract as sole carbon source revealed that the organism produces a copolymer of PHB-co-PHV (94.4:5.6) having molecular weight M(w) 1.394 × 10(6) and melting temperature 168.9 °C. Production of PHA by H. campisalis using aqueous extract of fruit peels and a copolymer PHB-co-PHV using aqueous extract of bagasse is presumably the first report. Copyright © 2014 Elsevier B.V. All rights reserved.

Utilization and environmental management of residues from intensive animal production

USDA-ARS?s Scientific Manuscript database

Animal manures are traditional sources of nutrients in agriculture. Under proper management, manures provide nutrients to soil, reducing or eliminating the use of commercial fertilizers, as well as organic carbon that improves soil physical properties and soil health. However, excessive application ...

Streptococcus pneumoniae Can Utilize Multiple Sources of Hyaluronic Acid for Growth

PubMed Central

Marion, Carolyn; Stewart, Jason M.; Tazi, Mia F.; Burnaugh, Amanda M.; Linke, Caroline M.; Woodiga, Shireen A.

2012-01-01

The mechanisms by which Streptococcus pneumoniae obtains carbohydrates for growth during airway colonization remain to be elucidated. The low concentration of free carbohydrates in the normal human airway suggests that pneumococci must utilize complex glycan structures for growth. The glycosaminoglycan hyaluronic acid is present on the apical surface of airway epithelial cells. As pneumococci express a hyaluronate lyase (Hyl) that cleaves hyaluronic acid into disaccharides, we hypothesized that during colonization pneumococci utilize the released carbohydrates for growth. Hyaluronic acid supported significant pneumococcal growth in an hyl-dependent manner. A phosphoenolpyruvate-dependent phosphotransferase system (PTS) and an unsaturated glucuronyl hydrolase (Ugl) encoded downstream of hyl are also essential for growth on hyaluronic acid. This genomic arrangement is present in several other organisms, suggesting conservation of the utilization mechanism between species. In vivo experiments support the hypothesis that S. pneumoniae utilizes hyaluronic acid as a carbon source during colonization. We also demonstrate that pneumococci can utilize the hyaluronic acid capsule of other bacterial species for growth, suggesting an alternative carbohydrate source for pneumococcal growth. Together, these data support a novel function for pneumococcal degradation of hyaluronic acid in vivo and provide mechanistic details of growth on this glycosaminoglycan. PMID:22311922

Switching of metabolic programs in response to light availability is an essential function of the cyanobacterial circadian output pathway

PubMed Central

Puszynska, Anna M; O'Shea, Erin K

2017-01-01

The transcription factor RpaA is the master regulator of circadian transcription in cyanobacteria, driving genome-wide oscillations in mRNA abundance. Deletion of rpaA has no effect on viability in constant light conditions, but renders cells inviable in cycling conditions when light and dark periods alternate. We investigated the mechanisms underlying this viability defect, and demonstrate that the rpaA- strain cannot maintain appropriate energy status at night, does not accumulate carbon reserves during the day, and is defective in transcription of genes crucial for utilization of carbohydrate stores at night. Reconstruction of carbon utilization pathways combined with provision of an external carbon source restores energy charge and viability of the rpaA- strain in light/dark cycling conditions. Our observations highlight how a circadian output pathway controls and temporally coordinates essential pathways in carbon metabolism to maximize fitness of cells facing periodic energy limitations. DOI: http://dx.doi.org/10.7554/eLife.23210.001 PMID:28430105

The genome sequence of E. coli W (ATCC 9637): comparative genome analysis and an improved genome-scale reconstruction of E. coli

PubMed Central

2011-01-01

Background Escherichia coli is a model prokaryote, an important pathogen, and a key organism for industrial biotechnology. E. coli W (ATCC 9637), one of four strains designated as safe for laboratory purposes, has not been sequenced. E. coli W is a fast-growing strain and is the only safe strain that can utilize sucrose as a carbon source. Lifecycle analysis has demonstrated that sucrose from sugarcane is a preferred carbon source for industrial bioprocesses. Results We have sequenced and annotated the genome of E. coli W. The chromosome is 4,900,968 bp and encodes 4,764 ORFs. Two plasmids, pRK1 (102,536 bp) and pRK2 (5,360 bp), are also present. W has unique features relative to other sequenced laboratory strains (K-12, B and Crooks): it has a larger genome and belongs to phylogroup B1 rather than A. W also grows on a much broader range of carbon sources than does K-12. A genome-scale reconstruction was developed and validated in order to interrogate metabolic properties. Conclusions The genome of W is more similar to commensal and pathogenic B1 strains than phylogroup A strains, and therefore has greater utility for comparative analyses with these strains. W should therefore be the strain of choice, or 'type strain' for group B1 comparative analyses. The genome annotation and tools created here are expected to allow further utilization and development of E. coli W as an industrial organism for sucrose-based bioprocesses. Refinements in our E. coli metabolic reconstruction allow it to more accurately define E. coli metabolism relative to previous models. PMID:21208457

Biogeochemical snapshot of an urban water system: The Anacostia River, Washington DC

NASA Astrophysics Data System (ADS)

Macavoy, S.; Ewers, E.; Bushaw-Newton, K.

2007-12-01

Highly urbanized and contaminated with PAHs, heavy metals, and sewage, the Anacostia River flows through Maryland and Washington, DC into the tidal Potomac River. Efforts have been underway to assess the river's ecological integrity and to determine the extent of anthropogenic influences. This study examines the nutrients, bacterial biomarkers, organic material, and carbon, nitrogen and sulfur sources in the Anacostia. High biological oxygen demand and low nitrogen (0.33-0.56 mg /L)/phosphorus (0.014 - 0.021 mg/L) concentrations were observed in three areas of the river. Bacterial activity based on carbon source utilization was higher in sediment samples than in water column samples. While bacterial abundances were decreased in downstream areas of sediment; abundances increased in downstream areas in the water column. Downstream sites had higher nutrient concentrations and dissolved organic carbon (up to 13.7 mg/L). Odd-chain length and branched fatty acids (FAs) in the sediments indicated bacterial sources, but long chain FAs indicative of terrestrial primary production were also abundant in some sediments. Also dominant among methyl esters and ketones in some sediment and water column samples was methyl isobutyl ketone, a common industrial solvent and combustion by-product. Sediment carbon stable isotope analyses show a mix of autochthonous and allochthonous derived materials, but most carbon was derived from terrestrial sources (-23.3 to -31.7°). Sediment nitrogen stable isotopes ranged from -5.4 to. 5.6, showing nitrate uptake by plants and also recycling of nitrogen within the river. Sulfur sources were generally between 3 and -5, reflecting local sulfate sources and anaerobic sulfate reduction.

Catabolism and Detoxification of 1-Aminoalkylphosphonic Acids: N-Acetylation by the phnO Gene Product

PubMed Central

Hove-Jensen, Bjarne; McSorley, Fern R.; Zechel, David L.

2012-01-01

In Escherichia coli uptake and catabolism of organophosphonates are governed by the phnCDEFGHIJKLMNOP operon. The phnO cistron is shown to encode aminoalkylphosphonate N-acetyltransferase, which utilizes acetylcoenzyme A as acetyl donor and aminomethylphosphonate, (S)- and (R)-1-aminoethylphosphonate, 2-aminoethyl- and 3-aminopropylphosphonate as acetyl acceptors. Aminomethylphosphonate, (S)-1-aminoethylphosphonate, 2-aminoethyl- and 3-aminopropylphosphonate are used as phosphate source by E. coli phn+ strains. 2-Aminoethyl- or 3-aminopropylphosphonate but not aminomethylphosphonate or (S)-1-aminoethylphosphonate is used as phosphate source by phnO strains. Neither phn+ nor phnO strains can use (R)-1-aminoethylphosphonate as phosphate source. Utilization of aminomethylphosphonate or (S)-1-aminoethylphosphonate requires the expression of phnO. In the absence of phnO-expression (S)-1-aminoethylphosphonate is bacteriocidal and rescue of phnO strains requires the simultaneous addition of d-alanine and phosphate. An intermediate of the carbon-phosphorus lyase pathway, 5′-phospho-α-d-ribosyl 1′-(2-N-acetamidoethylphosphonate), a substrate for carbon-phosphorus lyase, was found to accumulate in cultures of a phnP mutant strain. The data show that the physiological role of N-acetylation by phnO-specified aminoalkylphosphonate N-acetyltransferase is to detoxify (S)-1-aminoethylphosphonate, an analog of d-alanine, and to prepare (S)-1-aminoethylphosphonate and aminomethylphosphonate for utilization of the phosphorus-containing moiety. PMID:23056305

In vitro fermentation of prebiotics by Lactobacillus plantarum CFR 2194: selectivity, viability and effect of metabolites on β-glucuronidase activity.

PubMed

Arenahalli Ningegowda, Madhu; Siddalingaiya Gurudutt, Prapulla

2012-03-01

Prebiotic Fructooligosaccharides (FOS) escape metabolism in upper GI tract undergo microbial metabolism in colon and thereby influence the nature, type and number of intestinal microbiota to improve host's health. The present study focuses on the ability of Lactobacillus plantarum CFR 2194 to utilize FOS as a selective carbon and energy source. The effect of fermentative metabolites of L. plantarum on the β-glucuronidase was also investigated. A total of 16 strains of lactobacilli were assessed for their ability to ferment oligosaccharides. L. plantarum CFR 2194, an isolate from kanjika was found to utilize FOS effectively. Lactic acid was the main metabolic end product, followed by acetic acid, butyric acid, formic acid and ethanol. The inhibitory effects of these metabolites have been confirmed through the reduction of β-glucuronidase activity. L. plantarum when co-cultured with β-glucuronidase producing E. coli, in a basal media containing FOS as an energy source, could inhibit the growth of the pathogen during the course of fermentation. The results showed that L. plantarum CFR 2194 has the ability to utilize the prebiotic FOS as a selective carbon and energy source. The organism could inhibit the growth of the pathogen which produces β-glucuronidase and lowered its activity by the metabolites of FOS which indicates the probable use of L. plantarum through dietary intervention in combating colon carcinogenesis.

Carbon and nitrogen utilization in two species of Red Sea corals along a depth gradient: Insights from stable isotope analysis of total organic material and lipids

NASA Astrophysics Data System (ADS)

Alamaru, Ada; Loya, Yossi; Brokovich, Eran; Yam, Ruth; Shemesh, Aldo

2009-09-01

We examined the utilization of carbon and nitrogen in two common Red Sea coral species (Stylophora pistillata and Favia favus), differing in colony morphology and polyp size, along a depth gradient down to 60 m. We describe the changes in C/N ratios and in the stable isotope composition of carbon and nitrogen of coral's tissue and algal symbionts. We also measured the carbon isotopic composition of the lipid fraction extracted from both coral tissue and algal symbionts in order to reveal the changes in the carbon source utilized by the host coral for lipid synthesis. The results show that for both species, δ13C decreases by 7-8‰ in animal tissue, algal symbionts and in the lipid fractions as depth increases. However, in contrast to previous reports, the difference between δ13C values of coral tissue and algal symbionts does not increase with depth. δ15N values of coral tissue and algal symbionts in both species do not correlate with depth suggesting that the heterotrophic capacity of these corals does not increase with depth. δ13C values of tissue lipids were depleted by an average of ˜3.5‰ compared to δ13C of the entire tissue at all depths. δ13C values of algal lipids were depleted by an average of ˜2‰ compared to δ13C of the entire zooxanthellae at all depths, indicating high efficiency of carbon recycling between the two symbiotic partners along the entire gradient. The depletion of lipids is attributed to the fractionation mechanism during lipid synthesis. In addition, for both species, δ13C values of algal lipids were enriched compared with δ13C of tissue lipids. In S. pistillata, the difference between δ13C values of tissue lipids and algal lipids increased linearly with depth, indicating a change in the sources of carbon utilized by the coral for lipid synthesis below 20 m from an autotrophic to a heterotrophic source. However, in F. favus, this average difference was ˜4 times larger compared to shallow S. pistillata and was constant along the entire depth gradient, suggesting that F. favus uses heterotrophically-acquired carbon for lipid synthesis regardless of depth. Overall, F. favus exhibited enriched δ13C and δ15N values compared to S. pistillata along the entire gradient. We attribute these differences to both morphological differences (i.e. colony morphology, tissue thickness and polyp size) between the two species and to a higher heterotrophy/autotrophy ratio in F. favus at all depths. The C/N ratio in S. pistillata tissue decreased with increasing water depth whereas in F. favus it remained constant. This reflects a higher heterotrophic capacity in the large polyped F. favus, at all depths.

Isolation and characterization of Pseudomonas aeruginosa strain SJTD-2 for degrading long-chain n-alkanes and crude oil.

PubMed

Xu, Jing; Liu, Huan; Liu, Jianhua; Liang, Rubing

2015-06-04

Oil pollution poses a severe threat to ecosystems, and bioremediation is considered as a safe and efficient alternative to physicochemical. for eliminating this contaminant. In this study, a gram-negative bacteria strain SJTD-2 isolated from oil-contaminated soil was found capable of utilizing n-alkanes and crude oil as sole energy sources. The efficiency of this strain in degrading these pollutants was analyzed. Strain SJTD-2 was identified on the basis of its phenotype, its physiological features, and a comparative genetic analysis using 16S rRNA sequence. Growth of strain SJTD-2 with different carbon sources (n-alkanes of different lengths and crude oil) was assessed, and the gas chromatography-mass spectrometry method was used to analyze the degradation efficiency of strain SJTD-2 for n-alkanes and petroleum by detecting the residual n-alkane concentrations. Strain SJTD-2 was identified as Pseudomonas aeruginosa based on the phenotype, physiological features, and 16S rRNA sequence analysis. This strain can efficiently decompose medium-chain and long-chain n-alkanes (C10-C26), and petroleum as its sole carbon sources. It preferred the long-chain n-alkanes (C18-C22), and n-docosane was considered as the best carbon source for its growth. In 48 h, 500 mg/L n-docosane could be degraded completely, and 2 g/L n-docosane was decomposed to undetectable levels within 72 h. Moreover, strain SJTD-2 could utilize about 88% of 2 g/L crude oil in 7days. Compared with other alkane-utilizing strains, strain SJTD-2 showed outstanding degradation efficiency for long-chain n-alkanes and high tolerance to petroleum at elevated concentrations. The isolation and characterization of strain SJTD-2 would help researchers study the mechanisms underlying the biodegradation of n-alkanes, and this strain could be used as a potential strain for environmental governance and soil bioremediation.

Rapid isolation of a facultative anaerobic electrochemically active bacterium capable of oxidizing acetate for electrogenesis and azo dyes reduction.

PubMed

Shen, Nan; Yuan, Shi-Jie; Wu, Chao; Cheng, Yuan-Yuan; Song, Xiang-Ning; Li, Wen-Wei; Tong, Zhong-Hua; Yu, Han-Qing

2014-05-01

In this study, 27 strains of electrochemically active bacteria (EAB) were rapidly isolated and their capabilities of extracellular electron transfer were identified using a photometric method based on WO3 nanoclusters. These strains caused color change of WO3 from white to blue in a 24-well agar plate within 40 h. Most of the isolated EAB strains belonged to the genera of Aeromonas and Shewanella. One isolate, Pantoea agglomerans S5-44, was identified as an EAB that can utilize acetate as the carbon source to produce electricity and reduce azo dyes under anaerobic conditions. The results confirmed the capability of P. agglomerans S5-44 for extracellular electron transfer. The isolation of this acetate-utilizing, facultative EBA reveals the metabolic diversity of environmental bacteria. Such strains have great potential for environmental applications, especially at interfaces of aerobic and anaerobic environments, where acetate is the main available carbon source.

Low pressure steam expansion pretreatment as a competitive approach to improve diosgenin yield and the production of fermentable sugar from Dioscorea zingiberensis C.H. Wright.

PubMed

Wei, Mi; Tong, Yao; Wang, Hongbo; Wang, Lihua; Yu, Longjiang

2016-04-01

Development of efficient pretreatment methods which can disrupt the peripheral lignocellulose and even the parenchyma cells is of great importance for production of diosgenin from turmeric rhizomes. It was found that low pressure steam expansion pretreatment (LSEP) could improve the diosgenin yield by more than 40% compared with the case without pretreatment, while simultaneously increasing the production of fermentable sugar by 27.37%. Furthermore, little inhibitory compounds were produced in LSEP process which was extremely favorable for the subsequent biotransformation of fermentable sugar to other valuable products such as ethanol. Preliminary study showed that the ethanol yield when using the fermentable sugar as carbon source was comparable to that using glucose. The liquid residue of LSEP treated turmeric tuber after diosgenin production can be utilized as a quality fermentable carbon source. Therefore, LSEP has great potential in industrial application in diosgenin clean production and comprehensive utilization of turmeric tuber. Copyright © 2016 Elsevier Ltd. All rights reserved.

Metabolic influence of lead on polyhydroxyalkanoates (PHA) production and phosphate uptake in activated sludge fed with glucose or acetic acid as carbon source.

PubMed

You, Sheng-Jie; Tsai, Yung-Pin; Cho, Bo-Chuan; Chou, Yi-Hsiu

2011-09-01

Sludge in a sequential batch reactor (SBR) system was used to investigate the effect of lead toxicity on metabolisms of polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) communities fed with acetic acid or glucose as their sole carbon source, respectively. Results showed that the effect of lead on substrate utilization of both PAOs and GAOs was insignificant. However, lead substantially inhibited both of phosphate release and uptake of PAOs. In high concentration of acetic acid trials, an abnormal aerobic phosphate release was observed instead of phosphate uptake and the release rate increased with increasing lead concentration. Results also showed that PAOs could normally synthesize polyhydroxybutyrate (PHB) in the anaerobic phase even though lead concentration was 40 mg L(-1). However, they could not aerobically utilize PHB normally in the presence of lead. On the other hand, GAOs could not normally metabolize polyhydroxyvalerate (PHV) in both the anaerobic and aerobic phases. Copyright © 2011 Elsevier Ltd. All rights reserved.

Characterization and Genomic Analysis of a Highly Efficient Dibutyl Phthalate-Degrading Bacterium Gordonia sp. Strain QH-12.

PubMed

Jin, Decai; Kong, Xiao; Liu, Huijun; Wang, Xinxin; Deng, Ye; Jia, Minghong; Yu, Xiangyang

2016-06-25

A bacterial strain QH-12 isolated from activated sludge was identified as Gordonia sp. based on analysis of 16S rRNA gene sequence and was found to be capable of utilizing dibutyl phthalate (DBP) and other common phthalate esters (PAEs) as the sole carbon and energy source. The degradation kinetics of DBP under different concentrations by the strain QH-12 fit well with the modified Gompertz model (R² > 0.98). However, strain QH-12 could not utilize the major intermediate product phthalate (phthalic acid; PA) as the sole carbon and energy source, and only a little amount of PA was detected. The QH-12 genome analysis revealed the presence of putative hydrolase/esterase genes involved in PAEs-degradation but no phthalic acid catabolic gene cluster was found, suggesting that a novel degradation pathway of PAEs was present in Gordonia sp. QH-12. This information will be valuable for obtaining a more holistic understanding on diverse genetic mechanisms of PAEs-degrading Gordonia sp. strains.

Utilization of xylose as a carbon source for mixotrophic growth of Scenedesmus obliquus.

PubMed

Yang, Suling; Liu, Guijun; Meng, Youting; Wang, Ping; Zhou, Sijing; Shang, Hongzhong

2014-11-01

Mixotrophic cultivation is one potential mode for microalgae production, and an economically acceptable and environmentally sustainable organic carbon source is essential. The potential use of xylose for culturing Scenedesmus obliquus in a mixotrophic mode and physiological features of xylose-grown S. obliquus were studied. S. obliquus had a certain xylose tolerance, and was capable of utilizing xylose for growth. At a xylose concentration of 4gL(-1), the maximal cell density was 2.2gL(-1), being 2.9-fold of that under photoautotrophic condition and arriving to the level of mixotrophic growth using 4gL(-1) glucose. No changes in cellular morphology of the cells grown with or without xylose were detected. Fluorescence emission from photosystem II (PS II) relative to photosystem I (PS I) was decreased in mixotrophic cells, implying that the PSII activity was decreased. The biomass lipid content was enhanced and carbohydrate concentration was decreased, in relation to photoautotrophic controls. Copyright © 2014 Elsevier Ltd. All rights reserved.

Metabolic behavior and enzymatic aspects of denitrifying EBPR sludge in a continuous-flow anaerobic-anoxic system.

PubMed

Zafiriadis, Ilias; Ntougias, Spyridon; Kapagiannidis, Anastasios G; Aivasidis, Alexander

2013-10-01

The metabolic aspects of enhanced biological phosphorus removal (EBPR) were investigated for the first time in a continuous-flow anaerobic-anoxic plant fed with acetate, propionate, or substrates which are involved in the tricarboxylic acid and/or glyoxylate cycle, i.e., fumarate, malate, or oxaloacetate, as the sole carbon source. Although the polyphosphate-accumulating organisms (PAOs) population remained stable with any carbon source examined, no typical EBPR metabolism was observed during fumarate, malate, or oxaloacetate utilization. Specific enzymatic activities related to EBPR were determined in activated sludge homogenates and directly correlated with the nutrient metabolic rates. The experimental results indicated the direct involvement of alkaline phosphatase, pyrophosphatase, and exopolyphosphatase in the denitrifying EBPR process. Metabolic aspects of glyoxylate cycle enzymes are discussed with regard to the biomass anaerobic and anoxic activity. Process performance was highly influenced by the kind of substrate utilized, indicating that specific metabolic pathways should be followed to favor efficient EBPR.

Contribution of the Salmonella enterica KdgR Regulon to Persistence of the Pathogen in Vegetable Soft Rots

PubMed Central

George, Andrée S.; Salas González, Isai; Lorca, Graciela L.

2015-01-01

During their colonization of plants, human enteric pathogens, such as Salmonella enterica, are known to benefit from interactions with phytopathogens. At least in part, benefits derived by Salmonella from the association with a soft rot caused by Pectobacterium carotovorum were shown to be dependent on Salmonella KdgR, a regulator of genes involved in the uptake and utilization of carbon sources derived from the degradation of plant polymers. A Salmonella kdgR mutant was more fit in soft rots but not in the lesions caused by Xanthomonas spp. and Pseudomonas spp. Bioinformatic, phenotypic, and gene expression analyses demonstrated that the KdgR regulon included genes involved in uptake and metabolism of molecules resulting from pectin degradation as well as those central to the utilization of a number of other carbon sources. Mutant analyses indicated that the Entner-Doudoroff pathway, in part controlled by KdgR, was critical for the persistence within soft rots and likely was responsible for the kdgR phenotype. PMID:26682862

Methylobacterium populi sp. nov., a novel aerobic, pink-pigmented, facultatively methylotrophic, methane-utilizing bacterium isolated from poplar trees (Populus deltoides x nigra DN34).

PubMed

Van Aken, Benoit; Peres, Caroline M; Doty, Sharon Lafferty; Yoon, Jong Moon; Schnoor, Jerald L

2004-07-01

A pink-pigmented, aerobic, facultatively methylotrophic bacterium, strain BJ001T, was isolated from internal poplar tissues (Populus deltoidesxnigra DN34) and identified as a member of the genus Methylobacterium. Phylogenetic analyses showed that strain BJ001T is related to Methylobacterium thiocyanatum, Methylobacterium extorquens, Methylobacterium zatmanii and Methylobacterium rhodesianum. However, strain BJ001T differed from these species in its carbon-source utilization pattern, particularly its use of methane as the sole source of carbon and energy, an ability that is shared with only one other member of the genus, Methylobacterium organophilum. In addition, strain BJ001T is the only member of the genus Methylobacterium to be described as an endophyte of poplar trees. On the basis of its physiological, genotypic and ecological properties, the isolate is proposed as a member of a novel species of the genus Methylobacterium, Methylobacterium populi sp. nov. (type strain, BJ001T=ATCC BAA-705T=NCIMB 13946T).

Ground Source Geothermal District Heating and Cooling System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lowe, James William

2016-10-21

Ball State University converted its campus from a coal-fired steam boiler district heating system to a ground source heat pump geothermal district system that produces simultaneously hot water for heating and chilled water for cooling. This system will include the installation of 3,600 four hundred feet deep vertical closed loop boreholes making it the largest ground source geothermal district system in the country. The boreholes will act as heat exchangers and transfer heat by virtue of the earth’s ability to maintain an average temperature of 55 degree Fahrenheit. With growing international concern for global warming and the need to reducemore » worldwide carbon dioxide loading of the atmosphere geothermal is poised to provide the means to help reduce carbon dioxide emissions. The shift from burning coal to utilizing ground source geothermal will increase electrical consumption but an overall decrease in energy use and reduction in carbon dioxide output will be achieved. This achievement is a result of coupling the ground source geothermal boreholes with large heat pump chiller technology. The system provides the thermodynamic means to move large amounts of energy with limited energy input. Ball State University: http://cms.bsu.edu/About/Geothermal.aspx« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murzin, I.H.; Tompa, G.S.; Wei, J.

The authors report the results of using sputtering and negative carbon ion sources to prepare thin films of carbon nitride. In this work, they compare the structural, tribological, and optical properties of the carbon nitride films that were prepared by two different ion assisted techniques. In the first approach they used a magnetron gun to sputter deposit carbon in a nitrogen atmosphere. The second method utilized a beam of negatively charged carbon ions of 1 to 5 {micro}A/cm{sup 2} current density impinging the substrate simultaneously with a positive nitrogen ion beam produced by a Kaufman source. They were able tomore » synthesize microscopically smooth coatings with the carbon to nitrogen ratio of 1:0.47. These films possess wear rates lower than 5 {times} 10{sup {minus}7} mm{sup 3}/Nm and friction coefficients in the range of 0.16 to 0.6. Raman spectroscopy revealed that the magnetron sputtered films are more structurally disordered than those formed with the negative carbon ion gun. FTIR showed the presence of the C{triple_bond}N stretching mode in both types of films. Finally, spectroscopic ellipsometry produced films with dielectric constants as low as 2.3 in the photon energy range from 1.2 to 5 eV.« less

Amino acid production from rice straw and wheat bran hydrolysates by recombinant pentose-utilizing Corynebacterium glutamicum.

PubMed

Gopinath, Vipin; Meiswinkel, Tobias M; Wendisch, Volker F; Nampoothiri, K Madhavan

2011-12-01

Corynebacterium glutamicum wild type lacks the ability to utilize the pentose fractions of lignocellulosic hydrolysates, but it is known that recombinants expressing the araBAD operon and/or the xylA gene from Escherichia coli are able to grow with the pentoses xylose and arabinose as sole carbon sources. Recombinant pentose-utilizing strains derived from C. glutamicum wild type or from the L-lysine-producing C. glutamicum strain DM1729 utilized arabinose and/or xylose when these were added as pure chemicals to glucose-based minimal medium or when they were present in acid hydrolysates of rice straw or wheat bran. The recombinants grew to higher biomass concentrations and produced more L-glutamate and L-lysine, respectively, than the empty vector control strains, which utilized the glucose fraction. Typically, arabinose and xylose were co-utilized by the recombinant strains along with glucose either when acid rice straw and wheat bran hydrolysates were used or when blends of pure arabinose, xylose, and glucose were used. With acid hydrolysates growth, amino acid production and sugar consumption were delayed and slower as compared to media with blends of pure arabinose, xylose, and glucose. The ethambutol-triggered production of up to 93 ± 4 mM L-glutamate by the wild type-derived pentose-utilizing recombinant and the production of up to 42 ± 2 mM L-lysine by the recombinant pentose-utilizing lysine producer on media containing acid rice straw or wheat bran hydrolysate as carbon and energy source revealed that acid hydrolysates of agricultural waste materials may provide an alternative feedstock for large-scale amino acid production.

Ruthenium-Catalyzed Synthesis of Dialkoxymethane Ethers Utilizing Carbon Dioxide and Molecular Hydrogen.

PubMed

Thenert, Katharina; Beydoun, Kassem; Wiesenthal, Jan; Leitner, Walter; Klankermayer, Jürgen

2016-09-26

The synthesis of dimethoxymethane (DMM) by a multistep reaction of methanol with carbon dioxide and molecular hydrogen is reported. Using the molecular catalyst [Ru(triphos)(tmm)] in combination with the Lewis acid Al(OTf)3 resulted in a versatile catalytic system for the synthesis of various dialkoxymethane ethers. This new catalytic reaction provides the first synthetic example for the selective conversion of carbon dioxide and hydrogen into a formaldehyde oxidation level, thus opening access to new molecular structures using this important C1 source. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon isotope fractionation during microbial methane oxidation

NASA Astrophysics Data System (ADS)

Barker, James F.; Fritz, Peter

1981-09-01

Methane, a common trace constituent of groundwaters, occasionally makes up more than 20% of the total carbon in groundwaters1,2. In aerobic environments CH4-rich waters can enable microbial food chain supporting a mixed culture of bacteria with methane oxidation as the primary energy source to develop3. Such processes may influence the isotopic composition of the residual methane and because 13C/12C analyses have been used to characterize the genesis of methanes found in different environments, an understanding of the magnitude of such effects is necessary. In addition, carbon dioxide produced by the methane-utilizing bacteria can be added to the inorganic carbon pool of affected groundwaters. We found carbon dioxide experimentally produced by methane-utilizing bacteria to be enriched in 12C by 5.0-29.6‰, relative to the residual methane. Where methane-bearing groundwaters discharged into aerobic environments microbial methane oxidation occurred, with the residual methane becoming progressively enriched in 13C. Various models have been proposed to explain the 13C/12C and 14C content of the dissolved inorganic carbon (DIC) of groundwaters in terms of additions or losses during flow in the subsurface4,5. The knowledge of both stable carbon isotope ratios in various pools and the magnitude of carbon isotope fractionation during various processes allows geochemists to use the 13C/12C ratio of the DIC along with water chemistry to estimate corrected 14C groundwater ages4,5. We show here that a knowledge of the carbon isotope fractionation between CH4 and CO2 during microbial methane-utilization could modify such models for application to groundwaters affected by microbial methane oxidation.

Production and degradation of polyhydroxyalkanoates in waste environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, S.Y.; Choi, J.

1999-06-01

Polyhydroxyalkanoates (PHAs) are energy/carbon storage materials accumulated under unfavorable growth condition in the presence of excess carbon source. PHAs are attracting much attention as substitute for non-degradable petrochemically derived plastics because of their similar material properties to conventional plastics and complete biodegradability under natural environment upon disposal. In this paper, PHA production and degradation in waste environment as well as its role in biological phosphorus removal are reviewed. In biological phosphorus removal process, bacteria accumulating polyphosphate (poly P) uptake carbon substrates and accumulate these as PHA by utilizing energy from breaking down poly P under anaerobic conditions. In the followingmore » aerobic condition, accumulated PHA is utilized for energy generation and for the regeneration of poly P. PHA production from waste has been investigated in order to utilize abundant organic compounds in waste water. Since PHA content and PHA productivity that can be obtained are rather low, PHA production from waste product should be considered as a coupled process for reducing the amount of organic waste. PHAs can be rapidly degraded to completion in municipal anaerobic sludge by various microorganisms.« less

CO2 utilization: an enabling element to move to a resource- and energy-efficient chemical and fuel production.

PubMed

Ampelli, Claudio; Perathoner, Siglinda; Centi, Gabriele

2015-03-13

CO(2) conversion will be at the core of the future of low-carbon chemical and energy industry. This review gives a glimpse into the possibilities in this field by discussing (i) CO(2) circular economy and its impact on the chemical and energy value chain, (ii) the role of CO(2) in a future scenario of chemical industry, (iii) new routes for CO(2) utilization, including emerging biotechnology routes, (iv) the technology roadmap for CO(2) chemical utilization, (v) the introduction of renewable energy in the chemical production chain through CO(2) utilization, and (vi) CO(2) as a suitable C-source to move to a low-carbon chemical industry, discussing in particular syngas and light olefin production from CO(2). There are thus many stimulating possibilities offered by using CO(2) and this review shows this new perspective on CO(2) at the industrial, societal and scientific levels. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

Trace-gas metabolic versatility of the facultative methanotroph Methylocella silvestris.

PubMed

Crombie, Andrew T; Murrell, J Colin

2014-06-05

The climate-active gas methane is generated both by biological processes and by thermogenic decomposition of fossil organic material, which forms methane and short-chain alkanes, principally ethane, propane and butane. In addition to natural sources, environments are exposed to anthropogenic inputs of all these gases from oil and gas extraction and distribution. The gases provide carbon and/or energy for a diverse range of microorganisms that can metabolize them in both anoxic and oxic zones. Aerobic methanotrophs, which can assimilate methane, have been considered to be entirely distinct from utilizers of short-chain alkanes, and studies of environments exposed to mixtures of methane and multi-carbon alkanes have assumed that disparate groups of microorganisms are responsible for the metabolism of these gases. Here we describe the mechanism by which a single bacterial strain, Methylocella silvestris, can use methane or propane as a carbon and energy source, documenting a methanotroph that can utilize a short-chain alkane as an alternative to methane. Furthermore, during growth on a mixture of these gases, efficient consumption of both gases occurred at the same time. Two soluble di-iron centre monooxygenase (SDIMO) gene clusters were identified and were found to be differentially expressed during bacterial growth on these gases, although both were required for efficient propane utilization. This report of a methanotroph expressing an additional SDIMO that seems to be uniquely involved in short-chain alkane metabolism suggests that such metabolic flexibility may be important in many environments where methane and short-chain alkanes co-occur.

Acrylonitrile removal from synthetic wastewater and actual industrial wastewater with high strength nitrogen using a pure bacteria culture.

PubMed

Wang, C C; Lee, C M; Cheng, P W

2001-01-01

A gram-negative rod-shaped bacteria (strain AAS6), capable of utilizing acrylonitrile as the sole source of both carbon and nitrogen, was utilized to investigate the removal of acrylonitrile in ABS resin manufacturing wastewater. Both synthetic wastewater, containing a high concentration of acrylonitrile, and actual wastewater obtained from an ABS manufacturing factory were used. The result indicated that strain AAS6 was capable of completely removing acrylonitrile from synthetic wastewater containing less than 889 mg/l acrylonitrile and from actual industrial wastewater containing less than 400 mg/l acrylonitrile. Whether in synthetic wastewater or actual industrial wastewater, strain AAS6 showed approximately the same ability for acrylonitrile removal and used acrylic acid, a metabolic by-product of acrylonitrile, as the carbon source and ammonium as the nitrogen source. The bacteria could not directly metabolize other chemicals found in the actual industrial wastewater. However, its metabolic activities were not inhibited by the presence of compounds such as butadiene, styrene or acrylonitrile-styrene polymer. Thus, this strain is expected to play an important role in aeration tanks for treating ABS resin manufacturing wastewater.

Alcohol consumption and tolerance of Neurospora crassa

USDA-ARS?s Scientific Manuscript database

The alcohol consumption and tolerance of the ascomycete Neurospora crassa was investigated in this study. This fungus is able to utilize both native alcohol and non-native alcohols as carbon sources, yet little is known about the enzymes involved in these processes. The deletion of alcohol dehydroge...

Regulation of Nitrogen Metabolism by GATA Zinc Finger Transcription Factors in Yarrowia lipolytica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pomraning, Kyle R.; Bredeweg, Erin L.; Baker, Scott E.

ABSTRACT Fungi accumulate lipids in a manner dependent on the quantity and quality of the nitrogen source on which they are growing. In the oleaginous yeastYarrowia lipolytica, growth on a complex source of nitrogen enables rapid growth and limited accumulation of neutral lipids, while growth on a simple nitrogen source promotes lipid accumulation in large lipid droplets. Here we examined the roles of nitrogen catabolite repression and its regulation by GATA zinc finger transcription factors on lipid metabolism inY. lipolytica. Deletion of the GATA transcription factor genesgzf3andgzf2resulted in nitrogen source-specific growth defects and greater accumulation of lipids when the cells weremore » growing on a simple nitrogen source. Deletion ofgzf1, which is most similar to activators of genes repressed by nitrogen catabolite repression in filamentous ascomycetes, did not affect growth on the nitrogen sources tested. We examined gene expression of wild-type and GATA transcription factor mutants on simple and complex nitrogen sources and found that expression of enzymes involved in malate metabolism, beta-oxidation, and ammonia utilization are strongly upregulated on a simple nitrogen source. Deletion ofgzf3results in overexpression of genes with GATAA sites in their promoters, suggesting that it acts as a repressor, whilegzf2is required for expression of ammonia utilization genes but does not grossly affect the transcription level of genes predicted to be controlled by nitrogen catabolite repression. Both GATA transcription factor mutants exhibit decreased expression of genes controlled by carbon catabolite repression via the repressormig1, including genes for beta-oxidation, highlighting the complex interplay between regulation of carbon, nitrogen, and lipid metabolism. IMPORTANCENitrogen source is commonly used to control lipid production in industrial fungi. Here we identified regulators of nitrogen catabolite repression in the oleaginous yeastY. lipolyticato determine how the nitrogen source regulates lipid metabolism. We show that disruption of both activators and repressors of nitrogen catabolite repression leads to increased lipid accumulation via activation of carbon catabolite repression through an as yet uncharacterized method.« less

Utilization of structural steel in buildings.

PubMed

Moynihan, Muiris C; Allwood, Julian M

2014-08-08

Over one-quarter of steel produced annually is used in the construction of buildings. Making this steel causes carbon dioxide emissions, which climate change experts recommend be reduced by half in the next 37 years. One option to achieve this is to design and build more efficiently, still delivering the same service from buildings but using less steel to do so. To estimate how much steel could be saved from this option, 23 steel-framed building designs are studied, sourced from leading UK engineering firms. The utilization of each beam is found and buildings are analysed to find patterns. The results for over 10 000 beams show that average utilization is below 50% of their capacity. The primary reason for this low value is 'rationalization'-providing extra material to reduce labour costs. By designing for minimum material rather than minimum cost, steel use in buildings could be drastically reduced, leading to an equivalent reduction in 'embodied' carbon emissions.

Sialic Acid Catabolism Confers a Competitive Advantage to Pathogenic Vibrio cholerae in the Mouse Intestine▿

PubMed Central

Almagro-Moreno, Salvador; Boyd, E. Fidelma

2009-01-01

Sialic acids comprise a family of nine-carbon ketosugars that are ubiquitous on mammalian mucous membranes. However, sialic acids have a limited distribution among Bacteria and are confined mainly to pathogenic and commensal species. Vibrio pathogenicity island 2 (VPI-2), a 57-kb region found exclusively among pathogenic strains of Vibrio cholerae, contains a cluster of genes (nan-nag) putatively involved in the scavenging (nanH), transport (dctPQM), and catabolism (nanA, nanE, nanK, and nagA) of sialic acid. The capacity to utilize sialic acid as a carbon and energy source might confer an advantage to V. cholerae in the mucus-rich environment of the gut, where sialic acid availability is extensive. In this study, we show that V. cholerae can utilize sialic acid as a sole carbon source. We demonstrate that the genes involved in the utilization of sialic acid are located within the nan-nag region of VPI-2 by complementation of Escherichia coli mutants and gene knockouts in V. cholerae N16961. We show that nanH, dctP, nanA, and nanK are highly expressed in V. cholerae grown on sialic acid. By using the infant mouse model of infection, we show that V. cholerae ΔnanA strain SAM1776 is defective in early intestinal colonization stages. In addition, SAM1776 shows a decrease in the competitive index in colonization-competition assays comparing the mutant strain with both O1 El Tor and classical strains. Our data indicate an important relationship between the catabolism of sialic acid and bacterial pathogenesis, stressing the relevance of the utilization of the resources found in the host's environment. PMID:19564383

Sialic acid catabolism confers a competitive advantage to pathogenic vibrio cholerae in the mouse intestine.

PubMed

Almagro-Moreno, Salvador; Boyd, E Fidelma

2009-09-01

Sialic acids comprise a family of nine-carbon ketosugars that are ubiquitous on mammalian mucous membranes. However, sialic acids have a limited distribution among Bacteria and are confined mainly to pathogenic and commensal species. Vibrio pathogenicity island 2 (VPI-2), a 57-kb region found exclusively among pathogenic strains of Vibrio cholerae, contains a cluster of genes (nan-nag) putatively involved in the scavenging (nanH), transport (dctPQM), and catabolism (nanA, nanE, nanK, and nagA) of sialic acid. The capacity to utilize sialic acid as a carbon and energy source might confer an advantage to V. cholerae in the mucus-rich environment of the gut, where sialic acid availability is extensive. In this study, we show that V. cholerae can utilize sialic acid as a sole carbon source. We demonstrate that the genes involved in the utilization of sialic acid are located within the nan-nag region of VPI-2 by complementation of Escherichia coli mutants and gene knockouts in V. cholerae N16961. We show that nanH, dctP, nanA, and nanK are highly expressed in V. cholerae grown on sialic acid. By using the infant mouse model of infection, we show that V. cholerae DeltananA strain SAM1776 is defective in early intestinal colonization stages. In addition, SAM1776 shows a decrease in the competitive index in colonization-competition assays comparing the mutant strain with both O1 El Tor and classical strains. Our data indicate an important relationship between the catabolism of sialic acid and bacterial pathogenesis, stressing the relevance of the utilization of the resources found in the host's environment.

Robust, easily shaped, and epoxy-free carbon-fiber-aluminum cathodes for generating high-current electron beams.

PubMed

Liu, Lie; Li, Limin; Wen, Jianchun; Wan, Hong

2009-02-01

This paper presents the construction of carbon-fiber-aluminum (CFA) cathode by squeezing casting and its applications for generating high-current electron beams to drive high-power microwave sources. The fabrication process avoided using epoxy, a volatile deteriorating the vacuum system. These cathodes had a higher hardness than conventional aluminum, facilitating machining. After surface treatment, carbon fibers became the dominator determining emission property. A multineedle CFA cathode was utilized in a triode virtual cathode oscillator (vircator), powered by a approximately 450 kV, approximately 400 ns pulse. It was found that 300-400 MW, approximately 250 ns microwave was radiated at a dominant frequency of 2.6 GHz. Further, this cathode can endure high-current-density emission without detectable degradation in performance as the pulse shot proceeded, showing the robust nature of carbon fibers as explosive emitters. Overall, this new class of cold cathodes offers a potential prospect of developing high-current electron beam sources.

Carbon-free production of 2-deoxy-scyllo-inosose (DOI) in cyanobacterium Synechococcus elongatus PCC 7942.

PubMed

Watanabe, Satoru; Ozawa, Hiroaki; Kato, Hiroaki; Nimura-Matsune, Kaori; Hirayama, Toshifumi; Kudo, Fumitaka; Eguchi, Tadashi; Kakinuma, Katsumi; Yoshikawa, Hirofumi

2018-01-01

Owing to their photosynthetic capabilities, there is increasing interest in utilizing cyanobacteria to convert solar energy into biomass. 2-Deoxy-scyllo-inosose (DOI) is a valuable starting material for the benzene-free synthesis of catechol and other benzenoids. DOI synthase (DOIS) is responsible for the formation of DOI from d-glucose-6-phosphate (G6P) in the biosynthesis of 2-deoxystreptamine-containing aminoglycoside antibiotics such as neomycin and butirosin. DOI fermentation using a recombinant Escherichia coli strain has been reported, although a carbon source is necessary for high-yield DOI production. We constructed DOI-producing cyanobacteria toward carbon-free and sustainable DOI production. A DOIS gene derived from the butirosin producer strain Bacillus circulans (btrC) was introduced and expressed in the cyanobacterium Synechococcus elongatus PCC 7942. We ultimately succeeded in producing 400 mg/L of DOI in S. elongatus without using a carbon source. DOI production by cyanobacteria represents a novel and efficient approach for producing benzenoids from G6P synthesized by photosynthesis.

Utilization of aromatic compounds by the Penicillium strain Bi 7/2.

PubMed

Hofrichter, M; Scheibner, K

1993-01-01

The Penicillium strain Bi 7/2 utilized phenol, catechol, resorcinol, hydroquinone, pyrogallol, hydroxyhydroquinone, phloroglucinol, m- and p-cresol, orcinol, 4-methylcatechol, 4-methoxyphenol, 4-aminophenol, benzyl alcohol, benzoic acid, 2-, 3- and 4-hydroxybenzoic acid, anthranilic acid, protocatechuic acid and gallic acid as sole sources of carbon and energy. The central metabolites catechol, protocatechuic acid and hydroxyquinone could be determined by HPLC with diode-array detection. Pathways for the degradation of aromatic substances were proposed.

Evaluating microbial carbon sources in Athabasca oil sands tailings ponds using natural abundance stable and radiocarbon isotopes

NASA Astrophysics Data System (ADS)

Ahad, J. M.; Pakdel, H.

2013-12-01

Natural abundance stable (δ13C) and radiocarbon (Δ14C) isotopes of phospholipid fatty acids (PLFAs) were used to evaluate the carbon sources utilized by the active microbial populations in surface sediments from Athabasca oil sands tailings ponds. The absence of algal-specific PLFAs at three of the four sites investigated, in conjunction with δ13C signatures for PLFAs that were generally within ~3‰ of that reported for oil sands bitumen (~ -30‰), indicated that the microbial communities growing on petroleum constituents were dominated by aerobic heterotrophs. The Δ14C values of PLFAs ranged from -906 to -586‰ and pointed to a significant uptake of fossil carbon (up to ~90% of microbial carbon derived from petroleum), particularly in PLFAs (e.g., cy17:0 and cy19:0) often associated with petroleum hydrocarbon degrading bacteria. The comparatively higher levels of 14C in other, less specific PLFAs (e.g., 16:0) indicated the preferential uptake of younger organic matter by the general microbial population (~50-80% of microbial carbon derived from petroleum). Since the main carbon pools in tailings sediment were essentially 'radiocarbon dead' (i.e., no detectable 14C), the principal source for this modern carbon is considered to be the Athabasca River, which provides the bulk of the water used in the bitumen extraction process. The preferential uptake of the minor amount of young and presumably more biodegradable material present in systems otherwise dominated by recalcitrant petroleum constituents has important implications for remediation strategies. On the one hand, it implies that mining-related organic contaminants could persist in the environment long after tailings pond reclamation has begun. Alternatively, it may be that the young, labile organic matter provided by the Athabasca River plays an important role in stimulating or supporting the microbial utilization of petroleum carbon in oil sands tailings ponds via co-metabolism or priming processes. Further research needs to examine the role which priming processes play in controlling the fate of organic contaminants in Athabasca oil sands tailings ponds, such as understanding to what extent the addition of labile material may hinder or enhance microbial uptake of fossil carbon. This knowledge can be subsequently used to optimize conditions which favour natural attenuation processes in reclamation sites following mine closure.

Biosynthesis of Pyocyanine by a Paraffin Hydrocarbon-oxidizing Strain of Pseudomonas aeruginosa

PubMed Central

Lee, E. G.-H.; Walden, C. C.

1969-01-01

A paraffin-oxidizing bacterium, designated as Pseudomonas aeruginosa ATS-14, was isolated from soil samples obtained from the Athabasca “tar sands.” This strain utilized kerosene as the only carbon source of energy and produced a high concentration of pyocyanine in the culture medium. Aromatic carbons were not attacked, but C10 to C17n-alkanes were readily oxidized by the pseudomonad and formed pyocyanine. The highest yield of the pigment was obtained from hexadecane and heptadecane. PMID:4977219

Cross-regulation among arabinose, xylose and rhamnose utilization systems in E. coli.

PubMed

Choudhury, D; Saini, S

2018-02-01

Bacteria frequently encounter multiple sugars in their natural surroundings. While the dynamics of utilization of glucose-containing sugar mixtures have been well investigated, there are few reports addressing regulation of utilization of glucose-free mixtures particularly pentoses. These sugars comprise a considerable fraction in hemicellulose which can be converted by suitable biocatalysts to biofuels and other value-added products. Hence, understanding of transcriptional cross-regulation among different pentose sugar utilization systems is essential for successful development of industrial strains. In this work, we study mixed-sugar utilization with respect to three secondary carbon sources - arabinose, xylose and rhamnose at single-cell resolution in Escherichia coli. Our results reveal that hierarchical utilization among these systems is not strict but rather can be eliminated or reversed by altering the relative ratios of the preferred and nonpreferred sugars. Since transcriptional cross-regulation among pentose sugar systems operates through competitive binding of noncognate sugar-regulator complex, altering sugar concentrations is thought to eliminate nonspecific binding by affecting concentration of the regulator - sugar complexes. Plant biomass comprises of hexose and pentose sugar mixtures. These sugars are processed by micro-organisms to form products like biofuels, polymers etc. One of the major challenges with mixed-sugar processing by micro-organisms is hierarchical utilization of sugars due to cross-regulation among sugar systems. In this work, we discuss cross-regulation among three secondary carbon sources - arabinose, xylose and rhamnose. Our results show that cross-regulation between pentose sugars is complex with multiple layers of regulation. These aspects need to be addressed for effective design of processes to extract energy from biomass. © 2017 The Society for Applied Microbiology.

Co-fermentation of carbon sources by Enterobacter aerogenes ATCC 29007 to enhance the production of bioethanol.

PubMed

Thapa, Laxmi Prasad; Lee, Sang Jun; Yang, Xiao Guang; Yoo, Hah Young; Kim, Sung Bong; Park, Chulhwan; Kim, Seung Wook

2014-06-01

We investigated the enhancement of bioethanol production in Enterobacter aerogenes ATCC 29007 by co-fermentation of carbon sources such as glycerol, glucose, galactose, sucrose, fructose, xylose, starch, mannitol and citric acid. Biofuel production increases with increasing growth rate of microorganisms; that is why we investigated the optimal growth rate of E. aerogenes ATCC 29007, using mixtures of different carbon sources with glycerol. E. aerogenes ATCC 29007 was incubated in media containing each carbon source and glycerol; growth rate and bioethanol production improved in all cases compared to those in medium containing glycerol alone. The growth rate and bioethanol production were highest with mannitol. Fermentation was carried out at 37 °C for 18 h, pH 7, using 50 mL defined production medium in 100 mL serum bottles at 200 rpm. Bioethanol production under optimized conditions in medium containing 16 g/L mannitol and 20 g/L glycerol increased sixfold (32.10 g/L) than that containing glycerol alone (5.23 g/L) as the carbon source in anaerobic conditions. Similarly, bioethanol production using free cells in continuous co-fermentation also improved (27.28 g/L) when 90.37 % of 16 g/L mannitol and 67.15 % of 20 g/L glycerol were used. Although naturally existing or engineered microorganisms can ferment mixed sugars sequentially, the preferential utilization of glucose to non-glucose sugars often results in lower overall yield and productivity of ethanol. Here, we present new findings in E. aerogenes ATCC 29007 that can be used to improve bioethanol production by simultaneous co-fermentation of glycerol and mannitol.

Mutants of Yeast Defective in Sucrose Utilization

PubMed Central

Carlson, Marian; Osmond, Barbara C.; Botstein, David

1981-01-01

Utilization of sucrose as a source of carbon and energy in yeast (Saccharomyces) is controlled by the classical SUC genes, which confer the ability to produce the sucrose-degrading enzyme invertase (Mortimer and Hawthorne 1969). Mutants of S. cerevisiae strain S288C (SUC2+) unable to grow anaerobically on sucrose, but still able to use glucose, were isolated. Two major complementation groups were identified: twenty-four recessive mutations at the SUC2 locus (suc2-); and five recessive mutations defining a new locus, SNF1 (for sucrose nonfermenting), essential for sucrose utilization. Two minor complementation groups, each comprising a single member with a leaky sucrose-nonfermenting phenotype, were also identified. The suc2 mutations isolated include four suppressible amber mutations and five mutations apparently exhibiting intragenic complementation; complementation analysis and mitotic mapping studies indicated that all of the suc2 mutations are alleles of a single gene. These results suggest that SUC2 encodes a protein, probably a dimer or multimer. No invertase activity was detected in suc2 mutants.—The SNF1 locus is not tightly linked to SUC2. The snf1 mutations were found to be pleiotropic, preventing sucrose utilization by SUC2+ and SUC7+ strains, and also preventing utilization of galactose, maltose and several nonfermentable carbon sources. Although snf1 mutants thus display a petite phenotype, classic petite mutations do not interfere with utilization of sucrose, galactose or maltose. A common feature of all the carbon utilization systems affected by SNF1 is that all are regulated by glucose repression. The snf1 mutants were found to produce the constitutive nonglycosylated form of invertase, but failed to produce the glucose-repressible, glycosylated, secreted invertase. This failure cannot be attributed to a general defect in production of glycosylated and secreted proteins because synthesis of acid phosphatase, a glycosylated secreted protein not subject to glucose repression, was not affected by snf1 mutations. These findings suggest that the SNF1 locus is involved in the regulation of gene expression by glucose repression. PMID:7040163

3 CFR - Power Sector Carbon Pollution Standards

Code of Federal Regulations, 2014 CFR

2014-01-01

... gas emissions of new cars and light trucks through 2025 and heavy duty trucks through 2018. The EPA..., established fuel efficiency standards for cars and trucks as part of a harmonized national program. Both... Greenhouse Gas Emissions for New Stationary Sources: Electric Utility Generating Units,” 77 Fed. Reg. 22392...

Cellobiose fermenting yeast produces varied forms of native ß-glucosidase

USDA-ARS?s Scientific Manuscript database

The rapid growing yeast strain NRRL Y-50464 is robust to environmental stress and resistant to 2-furaldehyde (furfural) and 5-[hydroxymethyl]-2-furaldehyde (HMF). It is able to utilize cellobiose as its sole source of carbon and produces ethanol from lignocellulosic biomass by simultaneous saccharif...

78 FR 39533 - Power Sector Carbon Pollution Standards

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-01

..., issuing Clean Air Act standards limiting the greenhouse gas emissions of new cars and light trucks through... Department of Transportation, which, at the same time, established fuel efficiency standards for cars and... Sources: Electric Utility Generating Units,'' 77 Fed. Reg. 22392. In light of the information conveyed in...

NOVEL ORGANIZATION OF THE GENES FOR PHTHALATE DEGRADATION FROM BURKHOLDERIA CEPACIA DBO1

EPA Science Inventory

Burkholderia cepacia DBO1 is able to utilize phthalate as the sole source of carbon and energy for growth. Two overlapping cosmid clones containing the genes for phthalate degradation were isolated from this strain. Subcloning and activity analysis localized the genes for phthala...

CLASSIFICATION OF PAH-DEGRADING BACTERIA BY PAH UTILIZATION PATTERNS AND THE COMPARISON OF METABOLIC PRODUCTS

EPA Science Inventory

Bacterial strains capable of using either phenanthrene, fluoranthene, or pyrene as sole carbon and energy sources were isolated from 16 different soil samples collected from the United States, Germany, and Norway. Thirty one strains were isolated on fluoranthene and the other twe...

Study utilization of extractable petroleum hydrocarbons biodegradation waste as the main material for making solid fuels

NASA Astrophysics Data System (ADS)

Hendrianie, Nuniek; Juliastuti, Sri Rachmania; Ar-rosyidah, Fanny Husna; Rochman, Hilal Abdur

2017-05-01

Nowadays the existence of energy sources of oil and was limited. Therefore, it was important to searching for new innovations of renewable energy sources by utilizing the waste into a source of energy. On the other hand, the process of extractable petroleum hydrocarbons biodegradation generated sludge that had calorific value and untapped. Because of the need for alternative sources of energy innovation with the concept of zero waste and the fuel potential from extractable petroleum hydrocarbons biodegradation waste, so it was necessary to study the use of extractable petroleum hydrocarbons biodegradation waste as the main material for making solid fuel. In addition, sawdust is a waste that had a great quantities and also had a high calorific value to be mixed with extractable petroleum hydrocarbons biodegradation waste. The purpose of this study was to determine the characteristics of the extractable petroleum hydrocarbons biodegradation waste and to determine the potential and a combination of a mixture of extractable petroleum hydrocarbons biodegradation waste and sawdust which has the best calorific value. The variables of this study was the composition of the waste and sawdust as follows 1:1; 1:3; and 3:1 (mass of sawdust : mass of waste) and time of sawdust carbonization was 10, 15 and 20 minutes. Sawdust was carbonized to get the high heating value. The characteristic of main material and fuel analysis performed with proximate analysis. While the calorific value analysis was performed with a bomb calorimeter. From the research, it was known that extractable petroleum hydrocarbons biodegradation waste had a moisture content of 3.06%; volatile matter 19.98%; ash content of 0.56%; fixed carbon content of 76.4% and a calorific value of 717 cal/gram. And a mixture that had the highest calorific value (4286.5 cal/gram) achieved in comparison sawdust : waste (3:1) by carbonization of sawdust for 20 minutes.

Bio-Fuel Production Assisted with High Temperature Steam Electrolysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grant Hawkes; James O'Brien; Michael McKellar

2012-06-01

Two hybrid energy processes that enable production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure are presented. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), these two hybrid energy processes have the potential to provide a significant alternative petroleum source that could reduce dependence on imported oil. The first process discusses a hydropyrolysis unit with hydrogen addition from HTSE. Non-food biomass is pyrolyzed and converted to pyrolysis oil. The pyrolysis oil is upgraded with hydrogen addition from HTSE. This addition of hydrogen deoxygenates the pyrolysis oilmore » and increases the pH to a tolerable level for transportation. The final product is synthetic crude that could then be transported to a refinery and input into the already used transportation fuel infrastructure. The second process discusses a process named Bio-Syntrolysis. The Bio-Syntrolysis process combines hydrogen from HTSE with CO from an oxygen-blown biomass gasifier that yields syngas to be used as a feedstock for synthesis of liquid synthetic crude. Conversion of syngas to liquid synthetic crude, using a biomass-based carbon source, expands the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-blown biomass gasifier.« less

Reduction of CO2 emission by INCAM model in Malaysia biomass power plants during the year 2016.

PubMed

Amin, Nor Aishah Saidina; Talebian-Kiakalaieh, Amin

2018-03-01

As the world's second largest palm oil producer and exporter, Malaysia could capitalize on its oil palm biomass waste for power generation. The emission factors from this renewable energy source are far lower than that of fossil fuels. This study applies an integrated carbon accounting and mitigation (INCAM) model to calculate the amount of CO 2 emissions from two biomass thermal power plants. The CO 2 emissions released from biomass plants utilizing empty fruit bunch (EFB) and palm oil mill effluent (POME), as alternative fuels for powering steam and gas turbines, were determined using the INCAM model. Each section emitting CO 2 in the power plant, known as the carbon accounting center (CAC), was measured for its carbon profile (CP) and carbon index (CI). The carbon performance indicator (CPI) included electricity, fuel and water consumption, solid waste and waste-water generation. The carbon emission index (CEI) and carbon emission profile (CEP), based on the total monthly carbon production, were determined across the CPI. Various innovative strategies resulted in a 20%-90% reduction of CO 2 emissions. The implementation of reduction strategies significantly reduced the CO 2 emission levels. Based on the model, utilization of EFB and POME in the facilities could significantly reduce the CO 2 emissions and increase the potential for waste to energy initiatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evaluation of Sustainability of the Carbon and Silicon Ecosystem: From Nanoparticles to Macroworld

NASA Astrophysics Data System (ADS)

Dolin, V.

Rapid development of nanotechnologies has led to a complicated problem of utilization, storage and treatment of waste nanodevices of silicon and carbon origin. The processes of physico-chemical and biogeochemical destruction of carbon—silicon—uranium nanoparticles of Chernobyl origin has been studied. The period of half-destruction assessed by leaching of different radionuclide from particles is between 5 and 25 years. Natural ecosystems are generally of carbon and silicon origin. The behavior of radionuclide in natural media is observed over a period of 20 years. For the balance calculations we have utilized the Geochemical Transition Factor (GTF) that represents the quantity of substance, which is accumulated by living matter from the area unit. The main part of total carbon is involved in biogeochemical cycles in the forest ecosystem. Anthropogenic activity leads to a considerable imbalance of carbon isotopes. The distribution of carbon isotopes between different biotic levels demonstrates that radiocarbon of artificial emission is substantially less bio-available than those from natural sources. The environmental ability to recovery, lies in decontamination of carbon trophic circuits, is an order of magnitude greater than the rate of natural attenuation and corresponds to the removal of artificial matter from natural silicon media. The modern sustainability of the silicon and carbon ecosystem is determined by an insignificant quantity of artificial matter involved in biogeochemical cycles.

Granular activated carbons from broiler manure: physical, chemical and adsorptive properties.

PubMed

Lima, Isabel M; Marshall, Wayne E

2005-04-01

Broiler manure produced at large concentrated facilities poses risks to the quality of water and public health. This study utilizes broiler litter and cake as source materials for granular activated carbon production and optimizes conditions for their production. Pelletized manure samples were pyrolyzed at 700 degrees C for 1 h followed by activation in an inert atmosphere under steam at different water flow rates, for a period ranging from 15 to 75 min. Carbon physical and adsorptive properties were dependent on activation time and quantity of steam used as activant, yields varied from 18% to 28%, surface area varied from 253 to 548 m2/g and copper ion adsorption varied from 0.13 to 1.92 mmol Cu2+/g carbon. Best overall performing carbons were steam activated for 45 min at 3 ml/min. Comparative studies with commercial carbons revealed the broiler cake-based carbon as having the highest copper ion efficiency.

Halobacterium denitrificans sp. nov. - An extremely halophilic denitrifying bacterium

NASA Technical Reports Server (NTRS)

Tomlinson, G. A.; Jahnke, L. L.; Hochstein, L. I.

1986-01-01

Halobacterium denitrificans was one of several carbohydrate-utilizing, denitrifying, extremely halophilic bacteria isolated by anaerobic enrichment in the presence of nitrate. Anaerobic growth took place only when nitrate (or nitrite) was present and was accompanied by the production of dinitrogen. In the presence of high concentrations of nitrate (i.e., 0.5 percent), nitrous oxide and nitrite were also detected. When grown aerobically in a mineral-salts medium containing 0.005 percent yeast extract, H. denitrificans utilized a variety of carbohydrates as sources of carbon and energy. In every case, carbohydrate utilization was accompanied by acid production.

Halobacterium denitrificans sp. nov., an extremely halophilic denitrifying bacterium

NASA Technical Reports Server (NTRS)

Tomlinson, G. A.; Jahnke, L. L.; Hochstein, L. I.

1986-01-01

Halobacterium denitrificans was one of several carbohydrate-utilizing, denitrifying, extremely halophilic bacteria isolated by anaerobic enrichment in the presence of nitrate. Anaerobic growth took place only when nitrate (or nitrite) was present and was accompanied by the production of dinitrogen. In the presence of high concentrations of nitrate (i.e., 0.5 percent), nitrous oxide and nitrite were also detected. When grown aerobically in a mineral-salts medium containing 0.005 percent yeast extract, H. denitrificans utilized a variety of carbohydrates as sources of carbon and energy. In every case, carbohydrate utilization was accompanied by acid production.

Enhancing cell growth and lutein productivity of Desmodesmus sp. F51 by optimal utilization of inorganic carbon sources and ammonium salt.

PubMed

Xie, Youping; Zhao, Xurui; Chen, Jianfeng; Yang, Xuqiu; Ho, Shih-Hsin; Wang, Baobei; Chang, Jo-Shu; Shen, Ying

2017-11-01

The type and concentration of inorganic carbon and nitrogen sources were manipulated to improve cell growth and lutein productivity of Desmodesmus sp. F51. Using nitrate as nitrogen source, the better cell growth and lutein accumulation were obtained under 2.5% CO 2 supply when compared to the addition of NaHCO 3 or Na 2 CO 3 . To solve the pH variation problem of ammonium consumption, the strategy of using dual carbon sources (NaHCO 3 and CO 2 ) was explored. A lower bicarbonate-C: ammonium-N ratio led to a lower culture pH as well as lower lutein productivity, but significantly enhanced the auto-flocculation efficiency of the microalgal cells. The highest biomass productivity (939mg/L/d) and lutein productivity (5.22mg/L/d) were obtained when the bicarbonate-C/ammonium-N ratio and ammonium-N concentration were 1:1 and 150mg/L, respectively. The lutein productivity of 5.22mg/L/d is the highest value ever reported in the literature using batch phototrophic cultivation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tailor-made Molecular Cobalt Catalyst System for the Selective Transformation of Carbon Dioxide to Dialkoxymethane Ethers.

PubMed

Schieweck, Benjamin G; Klankermayer, Jürgen

2017-08-28

Herein a non-precious transition-metal catalyst system for the selective synthesis of dialkoxymethane ethers from carbon dioxide and molecular hydrogen is presented. The development of a tailored catalyst system based on cobalt salts in combination with selected Triphos ligands and acidic co-catalysts enabled a synthetic pathway, avoiding the oxidation of methanol to attain the formaldehyde level of the central CH 2 unit. This unprecedented productivity based on the molecular cobalt catalyst is the first example of a non-precious transition-metal system for this transformation utilizing renewable carbon dioxide sources. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pyrolysis of chromium rich tanning industrial wastes and utilization of carbonized wastes in metallurgical process.

PubMed

Tôrres Filho, Artur; Lange, Liséte Celina; de Melo, Gilberto Caldeira Bandeira; Praes, Gustavo Eduardo

2016-02-01

Pyrolysis is the thermal degradation of organic material in oxygen-free or very lean oxygen atmosphere. This study evaluates the use of pyrolysis for conversion of leather wastes from chromium tanning processes into Carbonized Leather Residues (CLR), and the utilization of CLR in metallurgical processes through the production of iron ore pellets. CLR was used to replace mineral coal in proportions of 10% and 25% on fixed carbon basis content in the mixtures for pellets preparation. Experimental conversions were performed on a pilot scale pyrolysis plant and a pelletizing reactor of the "pot grate" type. The results demonstrated the technical feasibility of using the charcoal product from animal origin as an energy source, with recovery of up to 76.47% of chromium contained in CLR in the final produced of iron ore pellets. Pellets with 25% replacement of fixed carbon in the coal showed an enhanced compressive strength, with an average value of 344kgfpellet(-1), compared to 300kgfpellet(-1) for standard produced pellets. Copyright © 2015. Published by Elsevier Ltd.

L-arabinose fermenting yeast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Min; Singh, Arjun; Suominen, Pirkko

An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

Complete genome sequence of Burkholderia sp. strain PAMC28687, a potential octopine-utilizing bacterium isolated from Antarctica lichen.

PubMed

Han, So-Ra; Yu, Sang-Cheol; Ahn, Do-Hwan; Park, Hyun; Oh, Tae-Jin

2016-05-20

We report the complete genome sequence of Burkholderia sp. PAMC28687, which was isolated from the Antarctica lichen Useea sp., for better understanding of its catabolic traits in utilizing octopine as a source of carbon/nitrogen between Burkholderia and lichen. The genome consists of three circular chromosomes with five circular plasmids for the total 6,881,273bp sized genome with a G+C content of 58.14%. Copyright © 2016 Elsevier B.V. All rights reserved.

L-arabinose fermenting yeast

DOEpatents

Zhang, Min; Singh, Arjun; Suominen, Pirkko; Knoshaug, Eric; Franden, Mary Ann; Jarvis, Eric

2014-09-23

An L-arabinose utilizing yeast strain is provided for the production of ethanol by introducing and expressing bacterial araA, araB and araD genes. L-arabinose transporters are also introduced into the yeast to enhance the uptake of arabinose. The yeast carries additional genomic mutations enabling it to consume L-arabinose, even as the only carbon source, and to produce ethanol. A yeast strain engineered to metabolize arabinose through a novel pathway is also disclosed. Methods of producing ethanol include utilizing these modified yeast strains.

Characterization of Acinetobacter baumannii strain PS3 in degradation of food emulsifiers

NASA Astrophysics Data System (ADS)

Nguyen, Ngoc Tuan; Tran, Tuyet Nhung; Ha, Thi Bich Ngoc

2018-04-01

Strain SP3 revealed the abilty to utilizes emulsifier which is widely used in the preparation of drugs, vaccines, food, cosmetics and skin care products as its sole carbon and energy source. Generation time ranges from 1.4 to 2.1 h on the polysorbate family. Strain was identified as Acinetobacter baumannii based on 16S rRNA gene and it could dispose 27 % polysorbate 80 within a day. The proposed mechanism for polysorbate utilization belongs to the β-oxidation.

Novel targets of the CbrAB/Crc carbon catabolite control system revealed by transcript abundance in Pseudomonas aeruginosa.

PubMed

Sonnleitner, Elisabeth; Valentini, Martina; Wenner, Nicolas; Haichar, Feth el Zahar; Haas, Dieter; Lapouge, Karine

2012-01-01

The opportunistic human pathogen Pseudomonas aeruginosa is able to utilize a wide range of carbon and nitrogen compounds, allowing it to grow in vastly different environments. The uptake and catabolism of growth substrates are organized hierarchically by a mechanism termed catabolite repression control (Crc) whereby the Crc protein establishes translational repression of target mRNAs at CA (catabolite activity) motifs present in target mRNAs near ribosome binding sites. Poor carbon sources lead to activation of the CbrAB two-component system, which induces transcription of the small RNA (sRNA) CrcZ. This sRNA relieves Crc-mediated repression of target mRNAs. In this study, we have identified novel targets of the CbrAB/Crc system in P. aeruginosa using transcriptome analysis in combination with a search for CA motifs. We characterized four target genes involved in the uptake and utilization of less preferred carbon sources: estA (secreted esterase), acsA (acetyl-CoA synthetase), bkdR (regulator of branched-chain amino acid catabolism) and aroP2 (aromatic amino acid uptake protein). Evidence for regulation by CbrAB, CrcZ and Crc was obtained in vivo using appropriate reporter fusions, in which mutation of the CA motif resulted in loss of catabolite repression. CbrB and CrcZ were important for growth of P. aeruginosa in cystic fibrosis (CF) sputum medium, suggesting that the CbrAB/Crc system may act as an important regulator during chronic infection of the CF lung.

Enhanced production of green tide algal biomass through additional carbon supply.

PubMed

de Paula Silva, Pedro H; Paul, Nicholas A; de Nys, Rocky; Mata, Leonardo

2013-01-01

Intensive algal cultivation usually requires a high flux of dissolved inorganic carbon (Ci) to support productivity, particularly for high density algal cultures. Carbon dioxide (CO2) enrichment can be used to overcome Ci limitation and enhance productivity of algae in intensive culture, however, it is unclear whether algal species with the ability to utilise bicarbonate (HCO3 (-)) as a carbon source for photosynthesis will benefit from CO2 enrichment. This study quantified the HCO3 (-) affinity of three green tide algal species, Cladophora coelothrix, Cladophora patentiramea and Chaetomorpha linum, targeted for biomass and bioenergy production. Subsequently, we quantified productivity and carbon, nitrogen and ash content in response to CO2 enrichment. All three species had similar high pH compensation points (9.7-9.9), and grew at similar rates up to pH 9, demonstrating HCO3 (-) utilization. Algal cultures enriched with CO2 as a carbon source had 30% more total Ci available, supplying twenty five times more CO2 than the control. This higher Ci significantly enhanced the productivity of Cladophora coelothrix (26%), Chaetomorpha linum (24%) and to a lesser extent for Cladophora patentiramea (11%), compared to controls. We demonstrated that supplying carbon as CO2 can enhance the productivity of targeted green tide algal species under intensive culture, despite their clear ability to utilise HCO3 (-).

Utilization of carbon sources in a northern Brazilian mangrove ecosystem

NASA Astrophysics Data System (ADS)

Giarrizzo, Tommaso; Schwamborn, Ralf; Saint-Paul, Ulrich

2011-12-01

Carbon and nitrogen stable isotope ratios ( 13C and 15N) and trophic level (TL) estimates based on stomach content analysis and published data were used to assess the contribution of autotrophic sources to 55 consumers in an intertidal mangrove creek of the Curuçá estuary, northern Brazil. Primary producers showed δ 13C signatures ranging between -29.2 and -19.5‰ and δ 15N from 3.0 to 6.3‰. The wide range of the isotopic composition of carbon of consumers (-28.6 to -17.1‰) indicated that different autotrophic sources are important in the intertidal mangrove food webs. Food web segregation structures the ecosystem into three relatively distinct food webs: (i) mangrove food web, where vascular plants contribute directly or indirectly via POM to the most 13C-depleted consumers (e.g. Ucides cordatus and zooplanktivorous food chains); (ii) algal food web, where benthic algae are eaten directly by consumers (e.g. Uca maracoani, mullets, polychaetes, several fishes); (iii) mixed food web where the consumers use the carbon from different primary sources (mainly benthivorous fishes). An IsoError mixing model was used to determine the contributions of primary sources to consumers, based on δ 13C values. Model outputs were very sensitive to the magnitude of trophic isotope fractionation and to the variability in 13C data. Nevertheless, the simplification of the system by a priori aggregation of primary producers allowed interpretable results for several taxa, revealing the segregation into different food webs.

Regulation of nitrogen metabolism by GATA zinc finger transcription factors in Yarrowia lipolytica

DOE PAGES

Pomraning, Kyle R.; Bredeweg, Erin L.; Baker, Scott E.; ...

2017-02-15

Here, fungi accumulate lipids in a manner dependent on the quantity and quality of the nitrogen source on which they are growing. In the oleaginous yeast Yarrowia lipolytica, growth on a complex source of nitrogen enables rapid growth and limited accumulation of neutral lipids, while growth on a simple nitrogen source promotes lipid accumulation in large lipid droplets. Here we examined the roles of nitrogen catabolite repression and its regulation by GATA zinc finger transcription factors on lipid metabolism in Y. lipolytica. Deletion of the GATA transcription factor genes gzf3 and gzf2 resulted in nitrogen source-specific growth defects and greatermore » accumulation of lipids when the cells were growing on a simple nitrogen source. Deletion of gzf1, which is most similar to activators of genes repressed by nitrogen catabolite repression in filamentous ascomycetes, did not affect growth on the nitrogen sources tested. We examined gene expression of wild-type and GATA transcription factor mutants on simple and complex nitrogen sources and found that expression of enzymes involved in malate metabolism, beta-oxidation, and ammonia utilization are strongly upregulated on a simple nitrogen source. Deletion of gzf3 results in overexpression of genes with GATAA sites in their promoters, suggesting that it acts as a repressor, while gzf2 is required for expression of ammonia utilization genes but does not grossly affect the transcription level of genes predicted to be controlled by nitrogen catabolite repression. Both GATA transcription factor mutants exhibit decreased expression of genes controlled by carbon catabolite repression via the repressor mig1, including genes for beta-oxidation, highlighting the complex interplay between regulation of carbon, nitrogen, and lipid metabolism.« less

Regulation of nitrogen metabolism by GATA zinc finger transcription factors in Yarrowia lipolytica

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pomraning, Kyle R.; Bredeweg, Erin L.; Baker, Scott E.

Here, fungi accumulate lipids in a manner dependent on the quantity and quality of the nitrogen source on which they are growing. In the oleaginous yeast Yarrowia lipolytica, growth on a complex source of nitrogen enables rapid growth and limited accumulation of neutral lipids, while growth on a simple nitrogen source promotes lipid accumulation in large lipid droplets. Here we examined the roles of nitrogen catabolite repression and its regulation by GATA zinc finger transcription factors on lipid metabolism in Y. lipolytica. Deletion of the GATA transcription factor genes gzf3 and gzf2 resulted in nitrogen source-specific growth defects and greatermore » accumulation of lipids when the cells were growing on a simple nitrogen source. Deletion of gzf1, which is most similar to activators of genes repressed by nitrogen catabolite repression in filamentous ascomycetes, did not affect growth on the nitrogen sources tested. We examined gene expression of wild-type and GATA transcription factor mutants on simple and complex nitrogen sources and found that expression of enzymes involved in malate metabolism, beta-oxidation, and ammonia utilization are strongly upregulated on a simple nitrogen source. Deletion of gzf3 results in overexpression of genes with GATAA sites in their promoters, suggesting that it acts as a repressor, while gzf2 is required for expression of ammonia utilization genes but does not grossly affect the transcription level of genes predicted to be controlled by nitrogen catabolite repression. Both GATA transcription factor mutants exhibit decreased expression of genes controlled by carbon catabolite repression via the repressor mig1, including genes for beta-oxidation, highlighting the complex interplay between regulation of carbon, nitrogen, and lipid metabolism.« less

Carbon Monoxide as an Electron Donor for the Biological Reduction of Sulphate

PubMed Central

Parshina, Sofiya N.; Sipma, Jan; Henstra, Anne Meint; Stams, Alfons J. M.

2010-01-01

Several strains of Gram-negative and Gram-positive sulphate-reducing bacteria (SRB) are able to use carbon monoxide (CO) as a carbon source and electron donor for biological sulphate reduction. These strains exhibit variable resistance to CO toxicity. The most resistant SRB can grow and use CO as an electron donor at concentrations up to 100%, whereas others are already severely inhibited at CO concentrations as low as 1-2%. Here, the utilization, inhibition characteristics, and enzymology of CO metabolism as well as the current state of genomics of CO-oxidizing SRB are reviewed. Carboxydotrophic sulphate-reducing bacteria can be applied for biological sulphate reduction with synthesis gas (a mixture of hydrogen and carbon monoxide) as an electron donor. PMID:20628586

Thermochemical generation of hydrogen and carbon dioxide

NASA Technical Reports Server (NTRS)

Lawson, Daniel D. (Inventor); England, Christopher (Inventor)

1984-01-01

Mixing of carbon in the form of high sulfur coal with sulfuric acid reduces the temperature of sulfuric acid decomposition from 830.degree. C. to between 300.degree. C. and 400.degree. C. The low temperature sulfuric acid decomposition is particularly useful in thermal chemical cycles for splitting water to produce hydrogen. Carbon dioxide is produced as a commercially desirable byproduct. Lowering of the temperature for the sulfuric acid decomposition or oxygen release step simplifies equipment requirements, lowers thermal energy input and reduces corrosion problems presented by sulfuric acid at conventional cracking temperatures. Use of high sulfur coal as the source of carbon for the sulfuric acid decomposition provides an environmentally safe and energy efficient utilization of this normally polluting fuel.

Isolation and Characterization of Anaerobic Bacteria for Symbiotic Recycling of Uric Acid Nitrogen in the Gut of Various Termites

PubMed Central

Thong-On, Arunee; Suzuki, Katsuyuki; Noda, Satoko; Inoue, Jun-ichi; Kajiwara, Susumu; Ohkuma, Moriya

2012-01-01

Recycling of the nitrogenous waste uric acid (UA) of wood-feeding termites by their gut bacteria is one of the significant aspects of symbiosis for the conservation of nitrogen sources. Diverse anaerobic UA-degrading bacteria comprising 16 species were isolated from the gut of eight termite species, and were assigned to Clostridia, Enterobacteriaceae, and low G+C Gram-positive cocci. UA-degrading Clostridia had never been isolated from termite guts. UA-degrading ability was sporadically distributed among phylogenetically various culturable anaerobic bacteria from termite guts. A strain of Clostridium sp., which was commonly isolated from three termite species and represented a probable new species in cluster XIVa of clostridia, utilized UA as a nitrogen source but not as a sole carbon and energy source. This feature is in clear contrast to that of well-studied purinolytic clostridia or previously isolated UA degraders from termite guts, which also utilize UA as a sole carbon and energy source. Ammonia is the major nitrogenous product of UA degradation. Various purines stimulated the growth of this strain when added to an otherwise growth-limiting, nitrogen poor medium. The bacterial species involved the recycling of UA nitrogen in the gut microbial community of termites are more diverse in terms of both taxonomy and nutritional physiology than previously recognized. PMID:22791052

Population Dynamics of a Lac(-) Strain of Escherichia Coli during Selection for Lactose Utilization

PubMed Central

Foster, P. L.

1994-01-01

During selection for lactose utilization, Lac(+) revertants of FC40, a Lac(-) strain of Escherichia coli, appear at a high rate. Yet, no Lac(+) revertants appear in the absence of lactose, or in its presence if the cells have another, unfulfilled requirement for growth. This study investigates more fully the population dynamics of FC40 when incubated in the absence of a carbon source or when undergoing selection for lactose utilization. In the absence of a carbon source, the viable cell numbers do not change over 6 days. When incubated in liquid lactose medium, Lac(-) cells do not undergo any measurable increase in numbers or in turbidity for at least 2 days. When FC40 is plated on lactose minimum medium in the presence of scavenger cells, the upper limit to the amount of growth of Lac(-) cells during 5 days is one doubling, and there is no evidence for turnover (i.e., a balance between growth and death). The presence of a minority population that could form microcolonies was not detected. The implications of these results, plus the fact that the appearance of Lac(+) revertants during lactose selection is nearly constant with time, are discussed in reference to several models that have been postulated to account for adaptive mutations. PMID:7828809

Method for forming synthesis gas using a plasma-catalyzed fuel reformer

DOEpatents

Hartvigsen, Joseph J; Elangovan, S; Czernichowski, Piotr; Hollist, Michele

2015-04-28

A method of forming a synthesis gas utilizing a reformer is disclosed. The method utilizes a reformer that includes a plasma zone to receive a pre-heated mixture of reactants and ionize the reactants by applying an electrical potential thereto. A first thermally conductive surface surrounds the plasma zone and is configured to transfer heat from an external heat source into the plasma zone. The reformer further includes a reaction zone to chemically transform the ionized reactants into synthesis gas comprising hydrogen and carbon monoxide. A second thermally conductive surface surrounds the reaction zone and is configured to transfer heat from the external heat source into the reaction zone. The first thermally conductive surface and second thermally conductive surface are both directly exposed to the external heat source. A corresponding apparatus and system are also disclosed herein.

Keratinolytic activity of Aspergillus fumigatus fresenius.

PubMed

Santos RMDB; Firmino, A A; de Sá, C M; Felix, C R

1996-12-01

Aspergillus fumigatus can utilize chicken feather keratin as its sole carbon and nitrogen source. Because enzymatic conversion of native keratin into readily usable products is of economic interest, this fungus was studied for its capacity to produce and secrete keratin-hydrolyzing proteinases. Substantial keratin-azure hydrolyzing activity was present in the culture fluid of keratin-containing media. Considerably lower activity was present in cultures containing glucose and nitrate as the carbon and nitrogen sources, or keratin plus glucose and nitrate. Secretion of keratin-hydrolyzing activity in A. fumigatus was induced by keratin but repressed by low-molecular-weight carbon and nitrogen sources. The amount of keratinolytic enzyme present in the culture fluid was dependent on the initial pH of the culture medium. The crude enzyme also hydrolyzed native keratin and casein in vitro. Hydrolysis was optimal at pH 9 and 45 degrees C. The crude enzyme was remarkably thermostable. At 70 degrees C, it retained about 90% of its original activity for 1.5 h. The obtained results indicated that the A. fumigatus keratinolytic enzyme may be suitable for enzymatic improvement of feather meal.

Emerging materials for lowering atmospheric carbon

DOE PAGES

Barkakaty, Balaka; Sumpter, Bobby G.; Ivanov, Ilia N.; ...

2016-12-08

CO 2 emissions from anthropogenic sources and the rate at which they increase could have deep global ramifications such as irreversible climate change and increased natural disasters. Because greater than 50% of anthropogenic CO 2 emissions come from small, distributed sectors such as homes, offices, and transportation sources, most renewable energy systems and on-site carbon capture technologies for reducing future CO 2 emissions cannot be effectively utilized. This problem might be mediated by considering novel materials and technologies for directly capturing/removing CO 2 from air. But, compared to materials for capturing CO 2 at on-site emission sources, materials for capturingmore » CO 2 directly from air must be more selective to CO 2, and should operate and be stable at near ambient conditions. Here, we briefly summarize the recent developments in materials for capturing carbon dioxide directly from air. Furthermore, we discuss the challenges in this field and offer a perspective for developing the current state-of-art and also highlight the potential of a few recent discoveries in materials science that show potential for advanced application of air capture technology.« less

Transcriptional regulation of the protein kinase a subunits in Saccharomyces cerevisiae during fermentative growth.

PubMed

Galello, Fiorella; Pautasso, Constanza; Reca, Sol; Cañonero, Luciana; Portela, Paula; Moreno, Silvia; Rossi, Silvia

2017-12-01

Yeast cells can adapt their growth in response to the nutritional environment. Glucose is the favourite carbon source of Saccharomyces cerevisiae, which prefers a fermentative metabolism despite the presence of oxygen. When glucose is consumed, the cell switches to the aerobic metabolism of ethanol, during the so-called diauxic shift. The difference between fermentative and aerobic growth is in part mediated by a regulatory mechanism called glucose repression. During glucose derepression a profound gene transcriptional reprogramming occurs and genes involved in the utilization of alternative carbon sources are expressed. Protein kinase A (PKA) controls different physiological responses following the increment of cAMP as a consequence of a particular stimulus. cAMP-PKA is one of the major pathways involved in the transduction of glucose signalling. In this work the regulation of the promoters of the PKA subunits during respiratory and fermentative metabolism are studied. It is demonstrated that all these promoters are upregulated in the presence of glycerol as carbon source through the Snf1/Cat8 pathway. However, in the presence of glucose as carbon source, the regulation of each PKA promoter subunits is different and only TPK1 is repressed by the complex Hxk2/Mig1 in the presence of active Snf1. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Role of Nitrogen and Carbon Transport, Regulation, and Metabolism Genes for Saccharomyces cerevisiae Survival In Vivo†

PubMed Central

Kingsbury, Joanne M.; Goldstein, Alan L.; McCusker, John H.

2006-01-01

Saccharomyces cerevisiae is both an emerging opportunistic pathogen and a close relative of pathogenic Candida species. To better understand the ecology of fungal infection, we investigated the importance of pathways involved in uptake, metabolism, and biosynthesis of nitrogen and carbon compounds for survival of a clinical S. cerevisiae strain in a murine host. Potential nitrogen sources in vivo include ammonium, urea, and amino acids, while potential carbon sources include glucose, lactate, pyruvate, and fatty acids. Using mutants unable to either transport or utilize these compounds, we demonstrated that no individual nitrogen source was essential, while glucose was the most significant primary carbon source for yeast survival in vivo. Hydrolysis of the storage carbohydrate glycogen made a slight contribution for in vivo survival compared with a substantial requirement for trehalose hydrolysis. The ability to sense and respond to low glucose concentrations was also important for survival. In contrast, there was little or no requirement in vivo in this assay for any of the nitrogen-sensing pathways, nitrogen catabolite repression, the ammonium- or amino acid-sensing pathways, or general control. By using auxotrophic mutants, we found that some nitrogenous compounds (polyamines, methionine, and lysine) can be acquired from the host, while others (threonine, aromatic amino acids, isoleucine, and valine) must be synthesized by the pathogen. Our studies provide insights into the yeast-host environment interaction and identify potential antifungal drug targets. PMID:16682459

The effect of activated carbon support surface modification on characteristics of carbon nanospheres prepared by deposition precipitation of Fe-catalyst

NASA Astrophysics Data System (ADS)

Kristianto, H.; Arie, A. A.; Susanti, R. F.; Halim, M.; Lee, J. K.

2016-11-01

In this study the effect of activated carbon support modification to synthesis of CNSs was observed. Modification of activated carbon was done by using nitric acid. The effect of modification was analyzed from its FTIR spectra. The Fe catalysts were deposited on to the support by using urea deposition precipitation method at various initial catalysts concentration. CNSs was synthesized by utilizing cooking palm oil as renewable carbon source, and pyrolized at 700°C for 1 hour under nitrogen atmosphere. The products obtained then analyzed using SEM-EDS, TEM, XRD, and Raman spectroscopy. The modification of activated carbon support had increased the oxygen functional group. This increase resulted on increase of metal catalysts deposited on activated carbon surface. Peak of C (100) was observed, while ID/IG of samples were obtained around 0.9, which is commonly obtained for CNSs. High catalysts loading on modified activated carbon support caused decomposition of CNSs and formation carbon onion.

Elucidation of the Metabolic Network of Helicobacter pylori J99 and Malaysian Clinical Strains by Phenotype Microarray.

PubMed

Lee, Woon Ching; Goh, Khean Lee; Loke, Mun Fai; Vadivelu, Jamuna

2017-02-01

Helicobacter pylori colonizes almost half of the human population worldwide. H. pylori strains are genetically diverse, and the specific genotypes are associated with various clinical manifestations including gastric adenocarcinoma, peptic ulcer disease (PUD), and nonulcer dyspepsia (NUD). However, our current knowledge of the H. pylori metabolism is limited. To understand the metabolic differences among H. pylori strains, we investigated four Malaysian H. pylori clinical strains, which had been previously sequenced, and a standard strain, H. pylori J99, at the phenotypic level. The phenotypes of the H. pylori strains were profiled using the Biolog Phenotype Microarray system to corroborate genomic data. We initiated the analyses by predicting carbon and nitrogen metabolic pathways from the H. pylori genomic data from the KEGG database. Biolog PM aided the validation of the prediction and provided a more intensive analysis of the H. pylori phenomes. We have identified a core set of metabolic nutrient sources that was utilized by all strains tested and another set that was differentially utilized by only the local strains. Pentose sugars are the preferred carbon nutrients utilized by H. pylori. The amino acids l-aspartic acid, d-alanine, and l-asparagine serve as both carbon and nitrogen sources in the metabolism of the bacterium. The phenotypic profile based on this study provides a better understanding on the survival of H. pylori in its natural host. Our data serve as a foundation for future challenges in correlating interstrain metabolic differences in H. pylori. © 2016 The Authors. Helicobacter Published by John Wiley & Sons Ltd.

Effect of forage energy intake and supplementation on marbling deposition in growing beef cattle.

USDA-ARS?s Scientific Manuscript database

Glucose is the primary carbon source for fatty acid synthesis in intramuscular fat, whereas, acetate is primarily utilized by subcutaneous fat. Our objective was to examine the effect of forage energy intake and type of fermentation on marbling deposition by stocker cattle grazing dormant native ra...

Combining observations in the reflective solar and thermal domains for improved carbon and energy flux estimation

USDA-ARS?s Scientific Manuscript database

This study investigates the utility of integrating remotely sensed estimates of leaf chlorophyll (Cab) into a therma-based Two-Source Energy Balance (TSEB) model that estimates land-surface CO2 and energy fluxes using an analytical, light-use-efficiency (LUE) based model of canopy resistance. The LU...

[Physiological and biochemical characteristics and capacity for polyhydroxyalkanoates synthesis in a glucose-utilizing strain of hydrogen-oxidizing bacteria, Ralstonia eutropha B8562].

PubMed

Volova, T G; Kozhevnikov, I V; Dolgopolova, Iu B; Trusova, M Iu; Kalacheva, G S; Aref'eva, Iu V

2005-01-01

The physiological, biochemical, genetic, and cultural characteristics of the glucose-utilizing mutant strain Ralstonia eutropha B8562 were investigated in comparison with the parent strain R. eutropha B5786. The morphological, cultural, and biochemical characteristics of strain R. eutropha B8562 were similar to those of strain R. eutropha B5786. Genetic analysis revealed differences between the 16S rRNA gene sequences of these strains. The growth characteristics of the mutant using glucose as the sole carbon and energy source were comparable with those of the parent strain grown on fructose. Strain B8562 was characterized by high yields of polyhydroxyalkanoate (PHA) from different carbon sources (CO2, fructose, and glucose). In batch culture with glucose under nitrogen limitation, PHA accumulation reached 90% of dry weight. In PHA, beta-hydroxybutyrate was predominant (over 99 mol %); beta-hydroxyvalerate (0.25-0.72 mol %) and beta-hydroxyhexanoate (0.008-1.5 mol %) were present as minor components. The strain has prospects as a PHA producer on glucose-containing media.

Utilization of waste bittern from saltern as a source for magnesium and an absorbent for carbon dioxide capture.

PubMed

Na, Choon-Ki; Park, Hyunju; Jho, Eun Hea

2017-10-01

During solar salt production, large quantities of bittern, a liquid by-product containing high inorganic substance concentrations, are produced. The purpose of this research was to examine the utilization of waste bittern generated from salterns as a source for Mg production and as an absorbent for carbon dioxide (CO 2 ) capture. The study was conducted in a sequential two-step process. At NaOH/Mg molar ratios of 2.70-2.75 and pH 9.5-10.0, > 99% Mg precipitation from the bittern was achieved. After washing with water, 100-120 g/L of precipitate containing 94% Mg(OH) 2 was recovered from the bittern. At the optimum NH 4 OH concentration of 5%, 120 g of sodium bicarbonate precipitate per liter of bittern were recovered, which was equivalent to 63 g CO 2 captured per liter of bittern. These results can be used to support the use of bittern as a resource and reduce economic losses during solar salt production.

Microbial biodiesel production from oil palm biomass hydrolysate using marine Rhodococcus sp. YHY01.

PubMed

Bhatia, Shashi Kant; Kim, Junyoung; Song, Hun-Seok; Kim, Hyun Joong; Jeon, Jong-Min; Sathiyanarayanan, Ganesan; Yoon, Jeong-Jun; Park, Kyungmoon; Kim, Yun-Gon; Yang, Yung-Hun

2017-06-01

The effect of various biomass derived inhibitors (i.e. furfural, hydroxymethylfurfural (HMF), vanillin, 4-hydroxy benzaldehyde (4-HB) and acetate) was investigated for fatty acid accumulation in Rhodococcus sp. YHY 01. Rhodococcus sp. YHY01 was able to utilize acetate, vanillin, and 4-HB for biomass production and fatty acid accumulation. The IC 50 value for furfural (3.1mM), HMF (3.2mM), vanillin (2.0mM), 4-HB (2.7mM) and acetate (3.7mM) was calculated. HMF and vanillin affect fatty acid composition and increase saturated fatty acid content. Rhodococcus sp. YHY 01 cultured with empty fruit bunch hydrolysate (EFBH) as the main carbon source resulted in enhanced biomass (20%) and fatty acid productivity (37%), in compression to glucose as a carbon source. Overall, this study showed the beneficial effects of inhibitory molecules on growth and fatty acid production, and support the idea of biomass hydrolysate utilization for biodiesel production by avoiding complex efforts to remove inhibitory compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Economics of carbon dioxide capture and utilization-a supply and demand perspective.

PubMed

Naims, Henriette

2016-11-01

Lately, the technical research on carbon dioxide capture and utilization (CCU) has achieved important breakthroughs. While single CO 2 -based innovations are entering the markets, the possible economic effects of a large-scale CO 2 utilization still remain unclear to policy makers and the public. Hence, this paper reviews the literature on CCU and provides insights on the motivations and potential of making use of recovered CO 2 emissions as a commodity in the industrial production of materials and fuels. By analyzing data on current global CO 2 supply from industrial sources, best practice benchmark capture costs and the demand potential of CO 2 utilization and storage scenarios with comparative statics, conclusions can be drawn on the role of different CO 2 sources. For near-term scenarios the demand for the commodity CO 2 can be covered from industrial processes, that emit CO 2 at a high purity and low benchmark capture cost of approximately 33 €/t. In the long-term, with synthetic fuel production and large-scale CO 2 utilization, CO 2 is likely to be available from a variety of processes at benchmark costs of approx. 65 €/t. Even if fossil-fired power generation is phased out, the CO 2 emissions of current industrial processes would suffice for ambitious CCU demand scenarios. At current economic conditions, the business case for CO 2 utilization is technology specific and depends on whether efficiency gains or substitution of volatile priced raw materials can be achieved. Overall, it is argued that CCU should be advanced complementary to mitigation technologies and can unfold its potential in creating local circular economy solutions.

Microorganism Utilization for Synthetic Milk Production

NASA Technical Reports Server (NTRS)

Morford, Megan A.; Khodadad, Christina Louise; Spencer, LaShelle E.; Richards, Jeffrey T.; Strayer, Richard F.; Caro, Janicce; Hummerick, Mary; Birmele, Michele N.; Wheeler, Raymond M.

2014-01-01

A desired architecture for long duration spaceflight, such as aboard the International Space Station (ISS) or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of this project was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel- through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms were optimized in the laboratory and the desired end-products, sugars and lipids, were analyzed. Trichoderma reesei, a known cellulolytic fungus, was utilized to drive the production of glucose, with the intent that the produced glucose would serve as the carbon source for milk fat production and be a substitute for the milk sugar lactose. Lipid production would be carried out by Rhodosporidium toruloides, yeast known to accumulate those lipids that are typically found in milk fat. Results showed that glucose and total lipid content were below what was expected during this phase of experimentation. In addition, individual analysis of six fatty acids revealed that the percentage of each fatty acid was lower than naturally produced bovine milk. Overall, this research indicates that microorganisms could be utilized to breakdown inedible solid waste to produce useable products.

Biodegradation of Nitriles in Shale Oil

PubMed Central

Aislabie, Jackie; Atlas, Ronald M.

1988-01-01

Enrichment cultures were obtained, after prolonged incubation on a shale oil as the sole source of nitrogen, that selectively degraded nitriles. Capillary gas chromatographic analyses showed that the mixed microbial populations in the enrichments degraded the homologous series of aliphatic nitriles but not the aliphatic hydrocarbons, aromatic hydrocarbons, or heterocyclic-nitrogen compounds found in this oil. Time course studies showed that lighter nitriles were removed more rapidly than higher-molecular-weight nitriles. A Pseudomonas fluorescens strain isolated from an enrichment, which was able to completely utilize the individual nitriles undecyl cyanide and undecanenitrile as sole sources of carbon and nitrogen, was unable to attack stearonitrile when provided alone as the growth substrate. A P. aeruginosa strain, also isolated from one of the enrichments, used nitriles but not aliphatic or aromatic hydrocarbons when the oil was used as a sole nitrogen source. However, when the shale oil was used as the sole source of carbon, aliphatic hydrocarbons in addition to nitriles were degraded but aromatic hydrocarbons were still not attacked by this P. aeruginosa strain. PMID:16347731

Compositional Analysis of Fine Particulate Matter in Fairbanks, Alaska

NASA Astrophysics Data System (ADS)

Nattinger, K.; Simpson, W. R.; Huff, D.

2015-12-01

Fairbanks, AK experiences extreme pollution episodes that result in winter violations of the fine particulate matter (PM2.5) National Ambient Air Quality Standards. This poses a significant health risk for the inhabitants of the area. These high levels result from trapping of pollution in a very shallow boundary layer due to local meteorology, but the role of primary (direct emission) of particulate matter versus secondary production (in the atmosphere) of particulate matter is not understood. Analysis of the PM2.5 composition is being conducted to provide insight into sources, trends, and chemistry. Methods are developed to convert carbon data from IMPROVE (post-2009 analysis method) to NIOSH (pre-2009 method) utilizing blank subtraction, sampler bias adjustment, and inter-method correlations from co-located samples. By converting all carbon measurements to a consistent basis, long-term trends can be analyzed. The approach shows excellent mass closure between PM2.5 mass reconstructed from constituents and gravimetric-analyzed mass. This approach could be utilized in other US locations where the carbon analysis methods also changed. Results include organic and inorganic fractional mass percentages, analyzed over an eight-year period for two testing sites in Fairbanks and two in the nearby city of North Pole. We focus on the wintertime (Nov—Feb) period when most air quality violations occur and find that the particles consist primarily of organic carbon, with smaller percentages of sulfate, elemental carbon, ammonium, and nitrate. The Fairbanks area PM2.5 organic carbon / elemental carbon partitioning matches the source profile of wood smoke. North Pole and Fairbanks PM2.5 have significant compositional differences, with North Pole having a larger percentage of organic matter. Mass loadings in SO42-, NO3-, and total PM2.5 mass correlate with temperature. Multi-year temporal trends show little if any change with a strong effect from temperature. Insights from this study regarding primary versus possible secondary PM2.5 production processes can help in identifying effective PM2.5 control strategies.

Periodically striped films produced from super-aligned carbon nanotube arrays.

PubMed

Liu, Kai; Sun, Yinghui; Liu, Peng; Wang, Jiaping; Li, Qunqing; Fan, Shoushan; Jiang, Kaili

2009-08-19

We report a novel way to draw films from super-aligned carbon nanotube arrays at large drawing angles. The obtained super-aligned carbon nanotube films have a periodically striped configuration with alternating thinner and thicker film sections, and the width of the stripes is equal to the height of the original arrays. Compared with ordinary uniform films, the striped films provide a better platform for understanding the mechanism of spinning films from arrays because carbon nanotube junctions are easily observed and identified at the boundary of the stripes. Further studies show that the carbon nanotube junctions are bottleneck positions for thermal conduction and mechanical strength of the film, but do not limit its electrical conduction. These films can be utilized as striped and high-degree polarized light emission sources. Our results will be valuable for new applications and future large-scale production of tunable super-aligned carbon nanotube films.

Carbon/Attapulgite Composites as Recycled Palm Oil-Decoloring and Dye Adsorbents

PubMed Central

Tian, Guangyan; Zhu, Yongfeng; Zong, Li; Kang, Yuru; Wang, Aiqin

2018-01-01

Activated clay minerals have been widely used in the edible oil refining industry for decolorization of crude oil by adsorption, and so far many methods have been used to improve their decolorization efficiency. Herein, we successfully prepared a series of carbon/attapulgite (C/APT) composite adsorbents by a one-step in-situ carbonization process with natural starch (St) as the carbon source. It has been revealed that the adsorbent had better decolorization efficiency for crude palm oil than acid-activated APT. However, more than a million tons of decolorized waste is produced every year in the oil-refining industry, which was often treated as solid waste and has not yet been reutilized effectively. In order to explore a viable method to recycle and reuse the decolorant, the waste decolorant was further prepared into new C/APT adsorbents for the removal of dyes from wastewater, and then the dyes adsorbed on the adsorbent were used as the carbon sources to produce new C/APT adsorbents by a cyclic carbonization process. The results showed that the adsorbents prepared from the decolorized waste could remove more than 99.5% of the methylene blue (MB), methyl violet (MV), and malachite green (MG) dyes from the simulated wastewater with the dye concentration of 200 mg/L, and the C/APT–Re adsorbent consecutively regenerated five times using the adsorbed dyes as a carbon source still exhibit good adsorption efficiency for dyes. As a whole, this process opens a new avenue to develop efficient decolorants of palm oil and achieves recyclable utilization of decolored waste. PMID:29316634

Physiological and genomic features of highly alkaliphilic hydrogen-utilizing Betaproteobacteria from a continental serpentinizing site

PubMed Central

Suzuki, Shino; Kuenen, J. Gijs; Schipper, Kira; van der Velde, Suzanne; Ishii, Shun’ichi; Wu, Angela; Sorokin, Dimitry Y.; Tenney, Aaron; Meng, XianYing; Morrill, Penny L.; Kamagata, Yoichi; Muyzer, Gerard; Nealson, Kenneth H.

2014-01-01

Serpentinization, or the aqueous alteration of ultramafic rocks, results in challenging environments for life in continental sites due to the combination of extremely high pH, low salinity and lack of obvious electron acceptors and carbon sources. Nevertheless, certain Betaproteobacteria have been frequently observed in such environments. Here we describe physiological and genomic features of three related Betaproteobacterial strains isolated from highly alkaline (pH 11.6) serpentinizing springs at The Cedars, California. All three strains are obligate alkaliphiles with an optimum for growth at pH 11 and are capable of autotrophic growth with hydrogen, calcium carbonate and oxygen. The three strains exhibit differences, however, regarding the utilization of organic carbon and electron acceptors. Their global distribution and physiological, genomic and transcriptomic characteristics indicate that the strains are adapted to the alkaline and calcium-rich environments represented by the terrestrial serpentinizing ecosystems. We propose placing these strains in a new genus ‘Serpentinomonas’. PMID:24845058

Bicarbonate-based cultivation of Dunaliella salina for enhancing carbon utilization efficiency.

PubMed

Kim, Ga-Yeong; Heo, Jina; Kim, Hee-Sik; Han, Jong-In

2017-08-01

In this study, bicarbonate was proposed as an alternative carbon source to overcome exceedingly low CO 2 fixation efficiency of conventional microalgae cultivation system. 5gL -1 of sodium bicarbonate was found to well support the growth of Dunaliella salina, showing 2.84-fold higher specific growth rate than a bicarbonate-free control. This bicarbonate-fed cultivation also could yield biomass productivity similar to that of CO 2 -based system as long as pH was controlled. While the supplied CO 2 , because of its being a gas, was mostly lost and only 3.59% of it was used for biomass synthesis, bicarbonate was effectively incorporated into the biomass with 91.40% of carbon utilization efficiency. This study showed that the bicarbonate-based microalgae cultivation is indeed possible, and can even become a truly environment-friendly and workable approach, provided that a CO 2 mineralization technology is concomitantly established. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physiological and genomic features of highly alkaliphilic hydrogen-utilizing Betaproteobacteria from a continental serpentinizing site.

PubMed

Suzuki, Shino; Kuenen, J Gijs; Schipper, Kira; van der Velde, Suzanne; Ishii, Shun'ichi; Wu, Angela; Sorokin, Dimitry Y; Tenney, Aaron; Meng, XianYing; Morrill, Penny L; Kamagata, Yoichi; Muyzer, Gerard; Nealson, Kenneth H

2014-05-21

Serpentinization, or the aqueous alteration of ultramafic rocks, results in challenging environments for life in continental sites due to the combination of extremely high pH, low salinity and lack of obvious electron acceptors and carbon sources. Nevertheless, certain Betaproteobacteria have been frequently observed in such environments. Here we describe physiological and genomic features of three related Betaproteobacterial strains isolated from highly alkaline (pH 11.6) serpentinizing springs at The Cedars, California. All three strains are obligate alkaliphiles with an optimum for growth at pH 11 and are capable of autotrophic growth with hydrogen, calcium carbonate and oxygen. The three strains exhibit differences, however, regarding the utilization of organic carbon and electron acceptors. Their global distribution and physiological, genomic and transcriptomic characteristics indicate that the strains are adapted to the alkaline and calcium-rich environments represented by the terrestrial serpentinizing ecosystems. We propose placing these strains in a new genus 'Serpentinomonas'.

Growth characteristics of a new methylomonad.

PubMed Central

Chen, B J; Hirt, W; Lim, H C; Tsao, G T

1977-01-01

A methylomonad culture was isolated from pond water and examined as a potential source of single-cell protein. A medium containing magnesium sulfate, ammonium hydroxide, sodium phosphate, tap water, and methanol supported the growth of the isolate. Optimal growth conditions in batch cultures for the organism were: temperature, 30 to 33 degrees C; pH 7.1; and phosphate concentration, 0.015 M. The minimum doubling time obtained was 1.6 h. The specific growth rate in batch culture was dependent on the methanol concentration, reaching a maximum around 0.2% (wt/vol). Growth inhibition was apparent above 0.3% (wt/vol), and growth was completely inhibited above 4.6% (wt/vol) methanol. Although the inhibitory effect of formaldehyde on the specific growth rate was much greater than that of formate, the organism utilized formaldehyde, but not formate, as a sole carbon and energy source in batch cultures. The isolate was identified primarily by its inability to utilize any carbon source other than methanol and formaldehyde for growth. Although it is capable of rapid growth on methanol, the organism showed a very weak catalase activity. The amino acid content of the cells compared favorably with the reference levels for the essential amino acids specific by the Food and Agricultural Organization of the United Nations. PMID:15510

Starch and starch hydrolysates are favorable carbon sources for bifidobacteria in the human gut.

PubMed

Liu, Songling; Ren, Fazheng; Zhao, Liang; Jiang, Lu; Hao, Yanling; Jin, Junhua; Zhang, Ming; Guo, Huiyuan; Lei, Xingen; Sun, Erna; Liu, Hongna

2015-03-01

Bifidobacteria are key commensals in human gut, and their abundance is associated with the health of their hosts. Although they are dominant in infant gut, their number becomes lower in adult gut. The changes of the diet are considered to be main reason for this difference. Large amounts of whole-genomic sequence data of bifidobacteria make it possible to elucidate the genetic interpretation of their adaptation to the nutrient environment. Among the nutrients in human gut, starch is a highly fermentable substrate and can exert beneficial effects by increasing bifidobacteria and/or being fermented to short chain fatty acids. In order to determine the potential substrate preference of bifidobacteria, we compared the glycoside hydrolase (GH) profiles of a pooled-bifidobacterial genome (PBG) with a representative microbiome (RM) of the human gut. In bifidobacterial genomes, only 15% of GHs contained signal peptides, suggesting their weakness in utilization of complex carbohydrate, such as plant cell wall polysaccharides. However, compared with other intestinal bacteria, bifidobacteiral genomes encoded more GH genes for degrading starch and starch hydrolysates, indicating that they have genetic advantages in utilizing these substrates. Bifidobacterium longum subsp. longum BBMN68 isolated from centenarian's faeces was used as a model strain to further investigate the carbohydrate utilization. The pathway for degrading starch and starch hydrolysates was the only complete pathway for complex carbohydrates in human gut. It is noteworthy that all of the GH genes for degrading starch and starch hydrolysates in the BBMN68 genome were conserved in all studied bifidobacterial strains. The in silico analyses of BBMN68 were further confirmed by growth experiments, proteomic and real-time quantitative PCR (RT-PCR) analyses. Our results demonstrated that starch and starch hydrolysates were the most universal and favorable carbon sources for bifidobacteria. The low amount of these carbon sources in adult intestine was speculated to contribute to the low relative abundance of bifidobacteria.

Ether Lipids of Planktonic Archaea in the Marine Water Column

PubMed Central

Hoefs, M.; Schouten, S.; De Leeuw, J. W.; King, L. L.; Wakeham, S. G.; Damste, J.

1997-01-01

Acyclic and cyclic biphytanes derived from the membrane ether lipids of archaea were found in water column particulate and sedimentary organic matter from several oxic and anoxic marine environments. Compound-specific isotope analyses of the carbon skeletons suggest that planktonic archaea utilize an isotopically heavy carbon source such as algal carbohydrates and proteins or dissolved bicarbonate. Due to their high preservation potential, these lipids provide a fossil record of planktonic archaea and suggest that they have thrived in marine environments for more than 50 million years. PMID:16535669

Isolation, identification and growth determination of lactic acid-utilizing yeasts from the ruminal fluid of dairy cattle.

PubMed

Sirisan, V; Pattarajinda, V; Vichitphan, K; Leesing, R

2013-08-01

Ruminal organic acid production, especially lactic acid, can be modified by feeding cattle highly concentrated diets, which have been shown to adversely affect dairy cattle health. Therefore, the use of lactic acid-utilizing organisms is considered to be a potential method for controlling lactic acid levels. This study was conducted to isolate and identify lactic acid-utilizing yeasts from the ruminal fluid of dairy cattle and to determine the specific growth rate and generation time when using lactic acid as a carbon source instead of glucose. Seventeen yeast isolates were examined in this study. Yeasts isolated from dairy cattle that were fed a high cassava pulp diet (HCP) had higher specific growth rates and shorter generation times than yeasts isolated from dairy cattle that were fed a high-concentrate diet (HC) and a mixed diet (M). The three most effective yeasts in terms of specific growth rate and generation time were Pichia kudriavzevii, Candida rugosa and Kodamaea ohmeri, with 99, 100 and 99% nucleotide identities, respectively. These three isolates could be used as potential probiotics in dairy cattle diets. This study demonstrates that yeasts isolated from the ruminal fluid of dairy cattle can utilize lactic acid as a carbon and energy source for growth. The isolated yeasts can be used as probiotic supplements for dairy cattle that are fed highly concentrated diets to reduce ruminal lactic acid production. © 2013 The Society for Applied Microbiology.

Carbon dioxide utilization in a microalga-based biorefinery: Efficiency of carbon removal and economic performance under carbon taxation.

PubMed

Wiesberg, Igor Lapenda; Brigagão, George Victor; de Medeiros, José Luiz; de Queiroz Fernandes Araújo, Ofélia

2017-12-01

Coal-fired power plants are major stationary sources of carbon dioxide and environmental constraints demand technologies for abatement. Although Carbon Capture and Storage is the most mature route, it poses severe economic penalty to power generation. Alternatively, this penalty is potentially reduced by Carbon Capture and Utilization, which converts carbon dioxide to valuable products, monetizing it. This work evaluates a route consisting of carbon dioxide bio-capture by Chlorella pyrenoidosa and use of the resulting biomass as feedstock to a microalgae-based biorefinery; Carbon Capture and Storage route is evaluated as a reference technology. The integrated arrangement comprises: (a) carbon dioxide biocapture in a photobioreactor, (b) oil extraction from part of the produced biomass, (b) gasification of remaining biomass to obtain bio-syngas, and (c) conversion of bio-syngas to methanol. Calculation of capital and operational expenditures are estimated based on mass and energy balances obtained by process simulation for both routes (Carbon Capture and Storage and the biorefinery). Capital expenditure for the biorefinery is higher by a factor of 6.7, while operational expenditure is lower by a factor of 0.45 and revenues occur only for this route, with a ratio revenue/operational expenditure of 1.6. The photobioreactor is responsible for one fifth of the biorefinery capital expenditure, with footprint of about 1000 ha, posing the most significant barrier for technical and economic feasibility of the proposed biorefinery. The Biorefinery and Carbon Capture and Storage routes show carbon dioxide capture efficiency of 73% and 48%, respectively, with capture cost of 139$/t and 304$/t. Additionally, the biorefinery has superior performance in all evaluated metrics of environmental impacts. Copyright © 2017 Elsevier Ltd. All rights reserved.

The AMP-Activated Protein Kinase Homolog Snf1 Concerts Carbon Utilization, Conidia Production and the Biosynthesis of Secondary Metabolites in the Taxol-Producer Pestalotiopsis microspora.

PubMed

Wang, Dan; Li, Yingying; Wang, Haichuan; Wei, Dongsheng; Akhberdi, Oren; Liu, Yanjie; Xiang, Biyun; Hao, Xiaoran; Zhu, Xudong

2018-01-24

Highly conserved, the Snf1/AMPK is a central regulator of carbon metabolism and energy production in the eukaryotes. However, its function in filamentous fungi has not been well established. In this study, we reported functional characterization of Snf1/AMPK in the growth, development and secondary metabolism in the filamentous fungus Pestalotiopsis microspora . By deletion of the yeast SNF1 homolog, we found that it regulated the utilization of carbon sources, e.g., sucrose, demonstrating a conserved function of this kinase in filamentous fungus. Importantly, several novel functions of SNF1 were unraveled. For instance, the deletion strain displayed remarkable retardation in vegetative growth and pigmentation and produced a diminished number of conidia, even in the presence of the primary carbon source glucose. Deletion of the gene caused damages in the cell wall as shown by its hypersensitivities to Calcofluor white and Congo red, suggesting a critical role of Snf1 in maintaining cell wall integrity. Furthermore, the mutant strain Δ snf1 was hypersensitive to stress, e.g., osmotic pressure (1 M sorbitol), drug G418 and heat shock, though the mechanism remains to be illustrated. Significantly, disruption of the gene altered the production of secondary metabolites. By high-performance liquid chromatography (HPLC) profiling, we found that Δ snf1 barely produced secondary metabolites, e.g., the known product pestalotiollide B. This study suggests that Snf1 is a key regulator in filamentous fungus Pestalotiopsis microspora concerting carbon metabolism and the filamentous growth, conidiation, cell wall integrity, stress tolerance and the biosynthesis of secondary metabolites.

The AMP-Activated Protein Kinase Homolog Snf1 Concerts Carbon Utilization, Conidia Production and the Biosynthesis of Secondary Metabolites in the Taxol-Producer Pestalotiopsis microspora

PubMed Central

Wang, Dan; Li, Yingying; Wang, Haichuan; Wei, Dongsheng; Akhberdi, Oren; Liu, Yanjie; Xiang, Biyun; Hao, Xiaoran; Zhu, Xudong

2018-01-01

Highly conserved, the Snf1/AMPK is a central regulator of carbon metabolism and energy production in the eukaryotes. However, its function in filamentous fungi has not been well established. In this study, we reported functional characterization of Snf1/AMPK in the growth, development and secondary metabolism in the filamentous fungus Pestalotiopsis microspora. By deletion of the yeast SNF1 homolog, we found that it regulated the utilization of carbon sources, e.g., sucrose, demonstrating a conserved function of this kinase in filamentous fungus. Importantly, several novel functions of SNF1 were unraveled. For instance, the deletion strain displayed remarkable retardation in vegetative growth and pigmentation and produced a diminished number of conidia, even in the presence of the primary carbon source glucose. Deletion of the gene caused damages in the cell wall as shown by its hypersensitivities to Calcofluor white and Congo red, suggesting a critical role of Snf1 in maintaining cell wall integrity. Furthermore, the mutant strain Δsnf1 was hypersensitive to stress, e.g., osmotic pressure (1 M sorbitol), drug G418 and heat shock, though the mechanism remains to be illustrated. Significantly, disruption of the gene altered the production of secondary metabolites. By high-performance liquid chromatography (HPLC) profiling, we found that Δsnf1 barely produced secondary metabolites, e.g., the known product pestalotiollide B. This study suggests that Snf1 is a key regulator in filamentous fungus Pestalotiopsis microspora concerting carbon metabolism and the filamentous growth, conidiation, cell wall integrity, stress tolerance and the biosynthesis of secondary metabolites. PMID:29364863

Nitrogen reduction pathways in estuarine sediments: Influences of organic carbon and sulfide

NASA Astrophysics Data System (ADS)

Plummer, Patrick; Tobias, Craig; Cady, David

2015-10-01

Potential rates of sediment denitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA) were mapped across the entire Niantic River Estuary, CT, USA, at 100-200 m scale resolution consisting of 60 stations. On the estuary scale, denitrification accounted for ~ 90% of the nitrogen reduction, followed by DNRA and anammox. However, the relative importance of these reactions to each other was not evenly distributed through the estuary. A Nitrogen Retention Index (NIRI) was calculated from the rate data (DNRA/(denitrification + anammox)) as a metric to assess the relative amounts of reactive nitrogen being recycled versus retained in the sediments following reduction. The distribution of rates and accompanying sediment geochemical analytes suggested variable controls on specific reactions, and on the NIRI, depending on position in the estuary and that these controls were linked to organic carbon abundance, organic carbon source, and pore water sulfide concentration. The relationship between NIRI and organic carbon abundance was dependent on organic carbon source. Sulfide proved the single best predictor of NIRI, accounting for 44% of its observed variance throughout the whole estuary. We suggest that as a single metric, sulfide may have utility as a proxy for gauging the distribution of denitrification, anammox, and DNRA.

Biodegradation of methyl parathion and p-nitrophenol: evidence for the presence of a p-nitrophenol 2-hydroxylase in a Gram-negative Serratia sp. strain DS001.

PubMed

Pakala, Suresh B; Gorla, Purushotham; Pinjari, Aleem Basha; Krovidi, Ravi Kumar; Baru, Rajasekhar; Yanamandra, Mahesh; Merrick, Mike; Siddavattam, Dayananda

2007-01-01

A soil bacterium capable of utilizing methyl parathion as sole carbon and energy source was isolated by selective enrichment on minimal medium containing methyl parathion. The strain was identified as belonging to the genus Serratia based on a phylogram constructed using the complete sequence of the 16S rRNA. Serratia sp. strain DS001 utilized methyl parathion, p-nitrophenol, 4-nitrocatechol, and 1,2,4-benzenetriol as sole carbon and energy sources but could not grow using hydroquinone as a source of carbon. p-Nitrophenol and dimethylthiophosphoric acid were found to be the major degradation products of methyl parathion. Growth on p-nitrophenol led to release of stoichiometric amounts of nitrite and to the formation of 4-nitrocatechol and benzenetriol. When these catabolic intermediates of p-nitrophenol were added to resting cells of Serratia sp. strain DS001 oxygen consumption was detected whereas no oxygen consumption was apparent when hydroquinone was added to the resting cells suggesting that it is not part of the p-nitrophenol degradation pathway. Key enzymes involved in degradation of methyl parathion and in conversion of p-nitrophenol to 4-nitrocatechol, namely parathion hydrolase and p-nitrophenol hydroxylase component "A" were detected in the proteomes of the methyl parathion and p-nitrophenol grown cultures, respectively. These studies report for the first time the existence of a p-nitrophenol hydroxylase component "A", typically found in Gram-positive bacteria, in a Gram-negative strain of the genus Serratia.

Green trees for greenhouse gases: a fair trade-off?

PubMed

Schmidt, C W

2001-03-01

While forests retain carbon in plants, detritus, and soils, utility companies spew it into the air as carbon dioxide, the main greenhouse gas behind global warming. Industrial carbon dioxide emissions aren't currently regulated by federal law, but a number of companies are trying to address the problem voluntarily by launching carbon sequestration programs in heavily forested countries, where carbon is contained in so-called sinks. But the November 2000 meeting of the Kyoto Protocol delegates in The Hague collapsed over the issue of the acceptability of carbon sinks as a source of carbon pollution credits, delivering what many see as a deathblow to the concept. At issue are a host of ecological and statistical questions, differing local land use practices, cultural factors, issues of verifiability, and even disagreement over definitions of basic terms such as "forest" Kyoto negotiators are gearing up for another round of discussions in Bonn in May 2001, and it is likely that the continuing debate over carbon sinks will dominate the agenda.

Straw and Xylan Utilization by Pure Cultures of Nitrogen-Fixing Azospirillum spp

PubMed Central

Halsall, Dorothy M.; Turner, Graham L.; Gibson, Alan H.

1985-01-01

Azospirillum spp. were shown to utilize both straw and xylan, a major component of straw, for growth with an adequate combined N supply and also under N-limiting conditions. For most strains examined, a semisolid agar medium was satisfactory, but several strains appeared to be capable of slow metabolism of the agar. Subsequently, experiments were done with acid-washed sand supplemented with various carbon sources. In these experiments, authenticated laboratory strains, and all 16 recent field isolates from straw-amended soils, of both A. brasilense and A. lipoferum possessed the ability to utilize straw and xylan as energy sources for nitrogen fixation. Neither carboxymethyl cellulose nor cellulose was utilized. The strains and isolates differed in their abilities to utilize xylan and straw and in the efficiency of nitrogenase activity (CO2/C2H2 ratio). Reasonable levels of activity could be maintained for at least 14 days in the sand cultures. Nitrogenase activity (acetylene reduction) was confirmed by 15N2 incorporation. The level of nitrogenase activity observed was dependent on the time of the addition of acetylene to the culture vessels. PMID:16346730

Integrated transcriptome sequencing and dynamic analysis reveal carbon source partitioning between terpenoid and oil accumulation in developing Lindera glauca fruits.

PubMed

Niu, Jun; Chen, Yinlei; An, Jiyong; Hou, Xinyu; Cai, Jian; Wang, Jia; Zhang, Zhixiang; Lin, Shanzhi

2015-10-08

Lindera glauca fruits (LGF) with the abundance of terpenoid and oil has emerged as a novel specific material for industrial and medicinal application in China, but the complex regulatory mechanisms of carbon source partitioning into terpenoid biosynthetic pathway (TBP) and oil biosynthetic pathway (OBP) in developing LGF is still unknown. Here we perform the analysis of contents and compositions of terpenoid and oil from 7 stages of developing LGF to characterize a dramatic difference in temporal accumulative patterns. The resulting 3 crucial samples at 50, 125 and 150 days after flowering (DAF) were selected for comparative deep transcriptome analysis. By Illumina sequencing, the obtained approximately 81 million reads are assembled into 69,160 unigenes, among which 174, 71, 81 and 155 unigenes are implicated in glycolysis, pentose phosphate pathway (PPP), TBP and OBP, respectively. Integrated differential expression profiling and qRT-PCR, we specifically characterize the key enzymes and transcription factors (TFs) involved in regulating carbon allocation ratios for terpenoid or oil accumulation in developing LGF. These results contribute to our understanding of the regulatory mechanisms of carbon source partitioning between terpenoid and oil in developing LGF, and to the improvement of resource utilization and molecular breeding for L. glauca.

Utilization of Dimethyl Sulfide as a Sulfur Source with the Aid of Light by Marinobacterium sp. Strain DMS-S1

PubMed Central

Fuse, Hiroyuki; Takimura, Osamu; Murakami, Katsuji; Yamaoka, Yukiho; Omori, Toshio

2000-01-01

Strain DMS-S1 isolated from seawater was able to utilize dimethyl sulfide (DMS) as a sulfur source only in the presence of light in a sulfur-lacking medium. Phylogenetic analysis based on 16S ribosomal DNA genes indicated that the strain was closely related to Marinobacterium georgiense. The strain produced dimethyl sulfoxide (DMSO), which was a main metabolite, and small amounts of formate and formaldehyde when grown on DMS as the sole sulfur source. The cells of the strain grown with succinate as a carbon source were able to use methyl mercaptan or methanesulfonate besides DMS but not DMSO or dimethyl sulfone as a sole sulfur source. DMS was transformed to DMSO primarily at wavelengths between 380 and 480 nm by heat-stable photosensitizers released by the strain. DMS was also degraded to formaldehyde in the presence of light by unidentified heat-stable factors released by the strain, and it appeared that strain DMS-S1 used the degradation products, which should be sulfite, sulfate, or methanesulfonate, as sulfur sources. PMID:11097944

Growth of the extremophilic Deinococcus geothermalis DSM 11302 using co-substrate fed-batch culture.

PubMed

Bornot, Julie; Molina-Jouve, Carole; Uribelarrea, Jean-Louis; Gorret, Nathalie

2014-02-01

Deinococcus geothermalis metabolism has been scarcely studied to date, although new developments on its utilization for bioremediation have been carried out. So, large-scale production of this strain and a better understanding of its physiology are required. A fed-batch experiment was conducted to achieve a high cell density non-limiting culture of D. geothermalis DSM 11302. A co-substrate nutritional strategy using glucose and yeast extract was carried out in a 20-L bioreactor in order to maintain a non-limited growth at a maximal growth rate of 1 h(-1) at 45 °C. Substrate supplies were adjusted by monitoring online culture parameters and physiological data (dissolved oxygen, gas analyses, respiratory quotient, biomass concentration). The results showed that yeast extract could serve as both carbon and nitrogen sources, although glucose and ammonia were consumed too. Yeast extract carbon-specific uptake rate reached a value 4.5 times higher than glucose carbon-specific uptake rate. Cell concentration of 9.6 g L(-1) dry cell weight corresponding to 99 g of biomass was obtained using glucose and yeast extract as carbon and nitrogen sources.

[Characteristics of microbial community and operation efficiency in biofilter process for drinking water purification].

PubMed

Xiang, Hong; Lü, Xi-Wu; Yang, Fei; Yin, Li-Hong; Zhu, Guang-Can

2011-04-01

In order to explore characteristics of microbial community and operation efficiency in biofilter (biologically-enhanced active filter and biological activated carbon filter) process for drinking water purification, Biolog and polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) techniques were applied to analyze the metabolic function and structure of microbial community developing in biofilters. Water quality parameters, such as NH; -N, NO; -N, permanganate index, UV254 and BDOC etc, were determined in inflow and outflow of biofilters for investigation of operation efficiency of the biofilters. The results show that metabolic capacity of microbial community of the raw water is reduced after the biofilters, which reflect that metabolically active microbial communities in the raw water can be intercepted by biofilters. After 6 months operation of biofilters, the metabolic profiles of microbial communities are similar between two kinds of biologically-enhanced active filters, and utilization of carbon sources of microbial communities in the two filters are 73.4% and 75.5%, respectively. The metabolic profiles of microbial communities in two biological activated carbon filters showed significant difference. The carbon source utilization rate of microbial community in granule-activated carbon filter is 79.6%, which is obviously higher than 53.8% of the rate in the columnar activated carbon filter (p < 0.01). The analysis results of PCR-SSCP indicate that microbial communities in each biofilter are variety, but the structure of dominant microorganisms is similar among different biofilters. The results also show that the packing materials had little effect on the structure and metabolic function of microbial community in biologically-enhanced active filters, and the difference between two biofilters for the water purification efficiency was not significant (p > 0.05). However, in biological activated carbon filters, granule-activated carbon is conducive to microbial growth and reproduction, and the microbial communities in the biofilter present high metabolic activities, and the removal efficiency for NH4(+)-N, permanganate index and BDOC is better than the columnar activated carbon filter(p < 0.05). The results also suggest that operation efficiency of biofilter is related to the metabolic capacity of microbial community in biofilter.

Carbohydrate Metabolism and Carbon Fixation in Roseobacter denitrificans OCh114

PubMed Central

Tang, Kuo-Hsiang; Feng, Xueyang; Tang, Yinjie J.; Blankenship, Robert E.

2009-01-01

The Roseobacter clade of aerobic marine proteobacteria, which compose 10–25% of the total marine bacterial community, has been reported to fix CO2, although it has not been determined what pathway is involved. In this study, we report the first metabolic studies on carbohydrate utilization, CO2 assimilation, and amino acid biosynthesis in the phototrophic Roseobacter clade bacterium Roseobacter denitrificans OCh114. We develop a new minimal medium containing defined carbon source(s), in which the requirements of yeast extract reported previously for the growth of R. denitrificans can be replaced by vitamin B12 (cyanocobalamin). Tracer experiments were carried out in R. denitrificans grown in a newly developed minimal medium containing isotopically labeled pyruvate, glucose or bicarbonate as a single carbon source or in combination. Through measurements of 13C-isotopomer labeling patterns in protein-derived amino acids, gene expression profiles, and enzymatic activity assays, we report that: (1) R. denitrificans uses the anaplerotic pathways mainly via the malic enzyme to fix 10–15% of protein carbon from CO2; (2) R. denitrificans employs the Entner-Doudoroff (ED) pathway for carbohydrate metabolism and the non-oxidative pentose phosphate pathway for the biosynthesis of histidine, ATP, and coenzymes; (3) the Embden-Meyerhof-Parnas (EMP, glycolysis) pathway is not active and the enzymatic activity of 6-phosphofructokinase (PFK) cannot be detected in R. denitrificans; and (4) isoleucine can be synthesized from both threonine-dependent (20% total flux) and citramalate-dependent (80% total flux) pathways using pyruvate as the sole carbon source. PMID:19794911

Utilization of structural steel in buildings

PubMed Central

Moynihan, Muiris C.; Allwood, Julian M.

2014-01-01

Over one-quarter of steel produced annually is used in the construction of buildings. Making this steel causes carbon dioxide emissions, which climate change experts recommend be reduced by half in the next 37 years. One option to achieve this is to design and build more efficiently, still delivering the same service from buildings but using less steel to do so. To estimate how much steel could be saved from this option, 23 steel-framed building designs are studied, sourced from leading UK engineering firms. The utilization of each beam is found and buildings are analysed to find patterns. The results for over 10 000 beams show that average utilization is below 50% of their capacity. The primary reason for this low value is ‘rationalization’—providing extra material to reduce labour costs. By designing for minimum material rather than minimum cost, steel use in buildings could be drastically reduced, leading to an equivalent reduction in ‘embodied’ carbon emissions. PMID:25104911

Single-cell protein from methanol with Enterobacter aerogenes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gnan, S.O.; Abodreheba, A.O.

1987-02-20

An identified Enterobacter aerogenes utilizing methanol as a sole carbon source was studied for the optimization of biomass production and the reduction of its nucleic acid content. Results indicated that the highest yield and conversion were obtained at 0.5% methanol. The addition of seawater as a source of trace elements has an adverse effect. However, the addition of urea as source of nitrogen enhanced the growth of E. aerogenes. Heat shock at 60 degrees C for one minute followed by incubation at 50 degrees C for 2 hours caused 72.6% reduction in the nucleic acid. 12 references.

Preparation of porous diatomite-templated carbons with large adsorption capacity and mesoporous zeolite K-H as a byproduct.

PubMed

Liu, Dong; Yuan, Weiwei; Deng, Liangliang; Yu, Wenbin; Sun, Hongjuan; Yuan, Peng

2014-06-15

In this study, KOH activation was performed to enhance the porosity of the diatomite-templated carbon and to increase its adsorption capacity of methylene blue (MB). In addition to serving as the activation agent, KOH was also used as the etchant to remove the diatomite templates. Zeolite K-H was synthesized as a byproduct via utilization of the resultant silicon- and potassium-containing solutions created from the KOH etching of the diatomite templates. The obtained diatomite-based carbons were composed of macroporous carbon pillars and tubes, which were derived from the replication of the diatomite templates and were well preserved after KOH activation. The abundant micropores in the walls of the carbon pillars and tubes were derived from the break and reconfiguration of carbon films during both the removal of the diatomite templates and KOH activation. Compared with the original diatomite-templated carbons and CO2-activated carbons, the KOH-activated carbons had much higher specific surface areas (988 m(2)/g) and pore volumes (0.675 cm(3)/g). Moreover, the KOH-activated carbons possessed larger MB adsorption capacity (the maximum Langmuir adsorption capacity: 645.2 mg/g) than those of the original carbons and CO2-activated carbons. These results showed that KOH activation was a high effective activation method. The zeolite K-H byproduct was obtained by utilizing the silicon- and potassium-containing solution as the silicon and potassium sources. The zeolite exhibited a stick-like morphology and possessed nanosized particles with a mesopore-predominant porous structure which was observed by TEM for the first time. Copyright © 2014 Elsevier Inc. All rights reserved.

Carbon Nanotube Patterning on a Metal Substrate

NASA Technical Reports Server (NTRS)

Nguyen, Cattien V. (Inventor)

2016-01-01

A CNT electron source, a method of manufacturing a CNT electron source, and a solar cell utilizing a CNT patterned sculptured substrate are disclosed. Embodiments utilize a metal substrate which enables CNTs to be grown directly from the substrate. An inhibitor may be applied to the metal substrate to inhibit growth of CNTs from the metal substrate. The inhibitor may be precisely applied to the metal substrate in any pattern, thereby enabling the positioning of the CNT groupings to be more precisely controlled. The surface roughness of the metal substrate may be varied to control the density of the CNTs within each CNT grouping. Further, an absorber layer and an acceptor layer may be applied to the CNT electron source to form a solar cell, where a voltage potential may be generated between the acceptor layer and the metal substrate in response to sunlight exposure.

Methanol Metabolism in Pseudomonad C

PubMed Central

Stieglitz, B.; Mateles, R. I.

1973-01-01

Cell suspensions of pseudomonad C, a bacterium capable of growth on methanol as sole carbon source, were able to oxidize methanol, formaldehyde, and formate, although the rates of oxidation for the latter two compounds were much slower. The latter compounds also could not serve as sole carbon sources. Through the use of labeled compounds, it was shown that in the presence of methanol, formaldehyde, formate, and bicarbonate were incorporated into trichloroacetic acid-precipitable material. Hexose phosphate synthetase activity was found, indicating the assimilation of methanol via an allulose pathway. No hydroxypyruvate reductase activity was found, nor was any complex membrane structure observed. Such a combination of characteristics has been observed in an obligate methylotroph (Pseudomonas W1), but pseudomonad C can utilize a variety of non-methyl substrates. Images PMID:4349032

Carbon isotopes of dissolved inorganic carbon reflect utilization of different carbon sources by microbial communities in two limestone aquifer assemblages

NASA Astrophysics Data System (ADS)

Nowak, Martin E.; Schwab, Valérie F.; Lazar, Cassandre S.; Behrendt, Thomas; Kohlhepp, Bernd; Totsche, Kai Uwe; Küsel, Kirsten; Trumbore, Susan E.

2017-08-01

Isotopes of dissolved inorganic carbon (DIC) are used to indicate both transit times and biogeochemical evolution of groundwaters. These signals can be complicated in carbonate aquifers, as both abiotic (i.e., carbonate equilibria) and biotic factors influence the δ13C and 14C of DIC. We applied a novel graphical method for tracking changes in the δ13C and 14C of DIC in two distinct aquifer complexes identified in the Hainich Critical Zone Exploratory (CZE), a platform to study how water transport links surface and shallow groundwaters in limestone and marlstone rocks in central Germany. For more quantitative estimates of contributions of different biotic and abiotic carbon sources to the DIC pool, we used the NETPATH geochemical modeling program, which accounts for changes in dissolved ions in addition to C isotopes. Although water residence times in the Hainich CZE aquifers based on hydrogeology are relatively short (years or less), DIC isotopes in the shallow, mostly anoxic, aquifer assemblage (HTU) were depleted in 14C compared to a deeper, oxic, aquifer complex (HTL). Carbon isotopes and chemical changes in the deeper HTL wells could be explained by interaction of recharge waters equilibrated with post-bomb 14C sources with carbonates. However, oxygen depletion and δ13C and 14C values of DIC below those expected from the processes of carbonate equilibrium alone indicate considerably different biogeochemical evolution of waters in the upper aquifer assemblage (HTU wells). Changes in 14C and 13C in the upper aquifer complexes result from a number of biotic and abiotic processes, including oxidation of 14C-depleted OM derived from recycled microbial carbon and sedimentary organic matter as well as water-rock interactions. The microbial pathways inferred from DIC isotope shifts and changes in water chemistry in the HTU wells were supported by comparison with in situ microbial community structure based on 16S rRNA analyses. Our findings demonstrate the large variation in the importance of biotic as well as abiotic controls on 13C and 14C of DIC in closely related aquifer assemblages. Further, they support the importance of subsurface-derived carbon sources like DIC for chemolithoautotrophic microorganisms as well as rock-derived organic matter for supporting heterotrophic groundwater microbial communities and indicate that even shallow aquifers have microbial communities that use a variety of subsurface-derived carbon sources.

Effects of pex1 disruption on wood lignin biodegradation, fruiting development and the utilization of carbon sources in the white-rot Agaricomycete Pleurotus ostreatus and non-wood decaying Coprinopsis cinerea.

PubMed

Nakazawa, Takehito; Izuno, Ayako; Horii, Masato; Kodera, Rina; Nishimura, Hiroshi; Hirayama, Yuichiro; Tsunematsu, Yuta; Miyazaki, Yasumasa; Awano, Tatsuya; Muraguchi, Hajime; Watanabe, Kenji; Sakamoto, Masahiro; Takabe, Keiji; Watanabe, Takashi; Isagi, Yuji; Honda, Yoichi

2017-12-01

Peroxisomes are well-known organelles that are present in most eukaryotic organisms. Mutant phenotypes caused by the malfunction of peroxisomes have been shown in many fungi. However, these have never been investigated in Agaricomycetes, which include white-rot fungi that degrade wood lignin in nature almost exclusively and play an important role in the global carbon cycle. Based on the results of a forward genetics study to identify mutations causing defects in the ligninolytic activity of the white-rot Agaricomycete Pleurotus ostreatus, we report phenotypes of pex1 disruptants in P. ostreatus, which are defective in two major features of white-rot Agaricomycetes: lignin biodegradation and mushroom formation. Pex1 disruption was also shown to cause defects in the hyphal growth of P. ostreatus on certain sawdust and minimum media. We also demonstrated that pex1 is essential for fruiting initiation in the non-wood decaying Agaricomycete Coprinopsis cinerea. However, unlike P. ostreatus, significant defects in hyphal growth on the aforementioned agar medium were not observed in C. cinerea. This result, together with previous C. cinerea genetic studies, suggests that the regulation mechanisms for the utilization of carbon sources are altered during the evolution of Agaricomycetes or Agaricales. Copyright © 2017 Elsevier Inc. All rights reserved.

Downhole Microseismic Monitoring at a Carbon Capture, Utilization, and Storage Site, Farnsworth Unit, Ochiltree County, Texas

NASA Astrophysics Data System (ADS)

Ziegler, A.; Balch, R. S.; van Wijk, J.

2015-12-01

Farnsworth Oil Field in North Texas hosts an ongoing carbon capture, utilization, and storage project. This study is focused on passive seismic monitoring at the carbon injection site to measure, locate, and catalog any induced seismic events. A Geometrics Geode system is being utilized for continuous recording of the passive seismic downhole bore array in a monitoring well. The array consists of 3-component dual Geospace OMNI-2400 15Hz geophones with a vertical spacing of 30.5m. Downhole temperature and pressure are also monitored. Seismic data is recorded continuously and is produced at a rate of over 900GB per month, which must be archived and reviewed. A Short Term Average/Long Term Average (STA/LTA) algorithm was evaluated for its ability to search for events, including identification and quantification of any false positive events. It was determined that the algorithm was not appropriate for event detection with the background level of noise at the field site and for the recording equipment as configured. Alternatives are being investigated. The final intended outcome of the passive seismic monitoring is to mine the continuous database and develop a catalog of microseismic events/locations and to determine if there is any relationship to CO2 injection in the field. Identifying the location of any microseismic events will allow for correlation with carbon injection locations and previously characterized geological and structural features such as faults and paleoslopes. Additionally, the borehole array has recorded over 1200 active sources with three sweeps at each source location that were acquired during a nearby 3D VSP. These data were evaluated for their usability and location within an effective radius of the array and were stacked to improve signal-noise ratio and are used to calibrate a full field velocity model to enhance event location accuracy. Funding for this project is provided by the U.S. Department of Energy under Award No. DE-FC26-05NT42591.

Genome Sequence of Pseudomonas aeruginosa Strain LCT-PA220, Which Was Selected after Space Flight by Using Biolog's Powerful Carbon Source Utilization Technology.

PubMed

Xu, Guogang; Hu, Juan; Fang, Xiangqun; Zhang, Xuelin; Wang, Junfeng; Guo, Yinghua; Li, Tianzhi; Chen, Zhenghong; Dai, Wenkui; Liu, Changting

2014-03-13

To explore the changes of Pseudomonas aeruginosa in space flight, we present the draft genome sequence of P. aeruginosa strain LCT-PA220, which originated from a P. aeruginosa strain, ATCC 27853, that traveled on the Shenzhou-VIII spacecraft.

Toxin-eating bacteria and bioremediation

DOEpatents

Church, George M; Dantas, Gautam; Sommer, Morten O

2014-02-25

Methods are provided for reducing a level of one or more antibiotics from an antibiotic-contaminated substance. An organism that can utilize the one or more antibiotics as a carbon source is cultured in the presence of the antibiotic-contaminated substance for a sufficient amount of time to reduce the level of one or more antibiotics from the antibiotic-contaminated substance.

Synergistic microbial consortium for bioenergy generation from complex natural energy sources.

PubMed

Wang, Victor Bochuan; Yam, Joey Kuok Hoong; Chua, Song-Lin; Zhang, Qichun; Cao, Bin; Chye, Joachim Loo Say; Yang, Liang

2014-01-01

Microbial species have evolved diverse mechanisms for utilization of complex carbon sources. Proper combination of targeted species can affect bioenergy production from natural waste products. Here, we established a stable microbial consortium with Escherichia coli and Shewanella oneidensis in microbial fuel cells (MFCs) to produce bioenergy from an abundant natural energy source, in the form of the sarcocarp harvested from coconuts. This component is mostly discarded as waste. However, through its usage as a feedstock for MFCs to produce useful energy in this study, the sarcocarp can be utilized meaningfully. The monospecies S. oneidensis system was able to generate bioenergy in a short experimental time frame while the monospecies E. coli system generated significantly less bioenergy. A combination of E. coli and S. oneidensis in the ratio of 1:9 (v:v) significantly enhanced the experimental time frame and magnitude of bioenergy generation. The synergistic effect is suggested to arise from E. coli and S. oneidensis utilizing different nutrients as electron donors and effect of flavins secreted by S. oneidensis. Confocal images confirmed the presence of biofilms and point towards their importance in generating bioenergy in MFCs.

Enhanced Production of Green Tide Algal Biomass through Additional Carbon Supply

PubMed Central

de Paula Silva, Pedro H.; Paul, Nicholas A.; de Nys, Rocky; Mata, Leonardo

2013-01-01

Intensive algal cultivation usually requires a high flux of dissolved inorganic carbon (Ci) to support productivity, particularly for high density algal cultures. Carbon dioxide (CO2) enrichment can be used to overcome Ci limitation and enhance productivity of algae in intensive culture, however, it is unclear whether algal species with the ability to utilise bicarbonate (HCO3 −) as a carbon source for photosynthesis will benefit from CO2 enrichment. This study quantified the HCO3 − affinity of three green tide algal species, Cladophora coelothrix, Cladophora patentiramea and Chaetomorpha linum, targeted for biomass and bioenergy production. Subsequently, we quantified productivity and carbon, nitrogen and ash content in response to CO2 enrichment. All three species had similar high pH compensation points (9.7–9.9), and grew at similar rates up to pH 9, demonstrating HCO3 − utilization. Algal cultures enriched with CO2 as a carbon source had 30% more total Ci available, supplying twenty five times more CO2 than the control. This higher Ci significantly enhanced the productivity of Cladophora coelothrix (26%), Chaetomorpha linum (24%) and to a lesser extent for Cladophora patentiramea (11%), compared to controls. We demonstrated that supplying carbon as CO2 can enhance the productivity of targeted green tide algal species under intensive culture, despite their clear ability to utilise HCO3 −. PMID:24324672

Microbial degradation of parathion. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Gibson, W. L.

1972-01-01

An organism capable of utilizing parathion as the sole carbon and energy source was isolated by enrichment culture techniques. The bacterium was characterized and tentatively classified as Pseudomonas aeruginosa. A pH of 7.0 - 7.5 and temperature of 30 C were found to be optimum for the consumption of parathion. Virtually no oxygen utilization was observed with resting cell suspensions when nonsolubilized parathion was employed. The use of ethanol as solvent for parathion in resting cell studies or preincubation of cells in ethanol obviated this problem and rapid parathion oxidation was demonstrable. Approximately 80% of the parathion consumed by resting cells was present terminally as carbon dioxide. Permeability of the cell to parathion or its metabolites was contingent upon the use of ethanol as either solvent or denaturant. Metabolites were tentatively identified by thin layer chromatography.

CO2 deserts: implications of existing CO2 supply limitations for carbon management.

PubMed

Middleton, Richard S; Clarens, Andres F; Liu, Xiaowei; Bielicki, Jeffrey M; Levine, Jonathan S

2014-10-07

Efforts to mitigate the impacts of climate change will require deep reductions in anthropogenic CO2 emissions on the scale of gigatonnes per year. CO2 capture and utilization and/or storage technologies are a class of approaches that can substantially reduce CO2 emissions. Even though examples of this approach, such as CO2-enhanced oil recovery, are already being practiced on a scale >0.05 Gt/year, little attention has been focused on the supply of CO2 for these projects. Here, facility-scale data newly collected by the U.S. Environmental Protection Agency was processed to produce the first comprehensive map of CO2 sources from industrial sectors currently supplying CO2 in the United States. Collectively these sources produce 0.16 Gt/year, but the data reveal the presence of large areas without access to CO2 at an industrially relevant scale (>25 kt/year). Even though some facilities with the capability to capture CO2 are not doing so and in some regions pipeline networks are being built to link CO2 sources and sinks, much of the country exists in "CO2 deserts". A life cycle analysis of the sources reveals that the predominant source of CO2, dedicated wells, has the largest carbon footprint further confounding prospects for rational carbon management strategies.

Induction of L-phenylalanine ammonia-lyase during utilization of phenylalanine as a carbon or nitrogen source in Rhodotorula glutinis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marusich, W.C.; Jensen, R.A.; Zamir, L.O.

Rhodotorula glutinis is a convenient source of L-phenylalanine ammonia-lyase, an enzyme that is useful as a biochemical reagent in the assay of L-phenylalanine. There have been previous descriptions of induced lyase production in complex medium where induction occurs late in exponential growth, suggesting a role in secondary metabolism such as is the case in higher plants. A higher specific activity of L-phenylalanine ammonia-lyase (sixfold higher than in complex medium) can be obtained during midexponential growth in a defined medium containing L-phenylalanine as the sole source of carbon. L-phenylalanine will also induce lyase synthesis during exponential growth in minimal medium inmore » which L-phenylalanine is the sole source of nitrogen. The appearance of lyase in complex medium supplemented with L-phenylalanine is probably triggered fortuitously by exhaustion late in growth of a prime source of nitrogen. In this study, R. glutinis appeared to express a single lyase enzyme, regardless of whether induction was nitrogen signaled or carbon signaled. Thin-layer chromatographic analysis of ether extracts prepared fom cultures induced with doubly labeled (U-/sup 14/C; ring-4-/sup 3/H) L-phenylalanine provided evidence of a catabolic sequence containing cinnamic acid, benzoic acid, and 4-hydroxybenzoic acid as degradative intermediates. 3,4-Dihydroxybenzoic acid was not identified as a catabolic intermediate.« less

Induction of L-phenylalanine ammonia-lyase during utilization of phenylalanine as a carbon or nitrogen source in Rhodotorula glutinis.

PubMed Central

Marusich, W C; Jensen, R A; Zamir, L O

1981-01-01

Rhodotorula glutinis is a convenient source of L-phenylalanine ammonia-lyase, an enzyme that is useful as a biochemical reagent in the assay of L-phenylalanine. There have been previous descriptions of induced lyase production in complex medium where induction occurs late in exponential growth, suggesting a role in secondary metabolism such as is the case in higher plants. A higher specific activity of L-phenylalanine ammonia-lyase (sixfold higher than a complex medium) can be obtained during midexponential growth in a defined medium containing L-phenylalanine as the sole source of carbon. L-Phenylalanine will also induce lyase synthesis during exponential growth in minimal in which L-phenylalanine is the sole source of nitrogen. The appearance of lyase in complex medium supplemented with L-phenylalanine is probably triggered fortuitously by exhaustion late in growth of a prime source of nitrogen. In this study, R. glutinis appeared to express a single lyase enzyme, regardless of whether induction was nitrogen signaled or carbon signaled. Thin-layer chromatographic analysis of ether extracts prepared from cultures induced with doubly labeled (U-14C; ring-4-3H) L-phenylalanine provided evidence of a catabolic sequence containing cinnamic acid, benzoic acid, and 4-hydroxybenzoic acid as degradative intermediates. 3,4-Dihydroxybenzoic acid was not identified as a catabolic intermediate. PMID:7195398

Nitrogen-doped porous carbon derived from biomass waste for high-performance supercapacitor.

PubMed

Ma, Guofu; Yang, Qian; Sun, Kanjun; Peng, Hui; Ran, Feitian; Zhao, Xiaolong; Lei, Ziqiang

2015-12-01

High capacitance property and low cost are the pivotal requirements for practical application of supercapacitor. In this paper, a low cost and high capacitance property nitrogen-doped porous carbon with high specific capacitance is prepared. The as-prepared nitrogen-doped porous carbon employing potato waste residue (PWR) as the carbon source, zinc chloride (ZnCl2) as the activating agent and melamine as nitrogen doping agent. The morphology and structure of the carbon materials are studied by scanning electron microscopy (SEM), N2 adsorption/desorption, X-ray diffraction (XRD) and Raman spectra. The surface area of the nitrogen-doped carbon which prepared under 700°C is found to be 1052m(2)/g, and the specific capacitance as high as 255Fg(-1) in 2M KOH electrolyte is obtained utilize the carbon as electrode materials. The electrode materials also show excellent cyclability with 93.7% coulombic efficiency at 5Ag(-1) current density of for 5000cycles. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal.

PubMed

Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi

2015-04-01

The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49-5.99 g N/(kg MLVSS⋅h) (MLVSS is mixed liquor volatile suspended solids) and 6.63-6.81 g N/(kg MLVSS⋅h), respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes.

Cassava stillage and its anaerobic fermentation liquid as external carbon sources in biological nutrient removal*

PubMed Central

Bu, Fan; Hu, Xiang; Xie, Li; Zhou, Qi

2015-01-01

The aim of this study was to investigate the effects of one kind of food industry effluent, cassava stillage and its anaerobic fermentation liquid, on biological nutrient removal (BNR) from municipal wastewater in anaerobic-anoxic-aerobic sequencing batch reactors (SBRs). Experiments were carried out with cassava stillage supernatant and its anaerobic fermentation liquid, and one pure compound (sodium acetate) served as an external carbon source. Cyclic studies indicated that the cassava by-products not only affected the transformation of nitrogen, phosphorus, poly-β-hydroxyalkanoates (PHAs), and glycogen in the BNR process, but also resulted in higher removal efficiencies for phosphorus and nitrogen compared with sodium acetate. Furthermore, assays for phosphorus accumulating organisms (PAOs) and denitrifying phosphorus accumulating organisms (DPAOs) demonstrated that the proportion of DPAOs to PAOs reached 62.6% (Day 86) and 61.8% (Day 65) when using cassava stillage and its anaerobic fermentation liquid, respectively, as the external carbon source. In addition, the nitrate utilization rates (NURs) of the cassava by-products were in the range of 5.49–5.99 g N/(kg MLVSS∙h) (MLVSS is mixed liquor volatile suspended solids) and 6.63–6.81 g N/(kg MLVSS∙h), respectively. The improvement in BNR performance and the reduction in the amount of cassava stillage to be treated in-situ make cassava stillage and its anaerobic fermentation liquid attractive alternatives to sodium acetate as external carbon sources for BNR processes. PMID:25845364

New Perspectives on Acetate and One-Carbon Metabolism in the Methanoarchaea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferry, James

Carbonic anhydrases catalyze the reversible hydration of carbon dioxide to bicarbonate. Although widespread in prokaryotes of the domains Bacteria and Archaea, few have been investigated and the physiological functions are largely unknown. Carbonic anhydrases are of biotechnological interest for carbon dioxide capture and sequestration at point sources. Prokaryotes encode three independently evolved classes. The alpha-class is restricted to a few pathogens and the other two are uniformly distributed in phylogenetically and physiologically diverse species. Although wide-spread in prokaryotes, only three gamma-class enzymes have been biochemically characterized and the physiological functions have not been investigated. The gamma-class is prominent in anaerobicmore » acetate-utilizing methane-producing species of the genus Methanosarcina that encode three subclasses. Enzymes from two of the subclasses, Cam and CamH from Methanosarcina thermophila, have been characterized and found to utilize iron in the active site which is the first example of an iron-containing carbonic anhydrase. No representative of the third subclass has been isolated, although this subclass constitutes the great majority of the β-class. This grant application proposed to characterize gamma-class carbonic anhydrases from diverse anaerobic prokaryotes from the domains Bacteria and Archaea to broaden the understanding of this enzyme. In particular, the three subclasses present the genetically tractable acetate-utilizing methanogen Methanosarcina acetivorans will be investigated to extend studies of acetate and one-carbon metabolism in this species. A genetic approach will be taken to ascertain the physiological functions. It is also proposed to delve deeper into the mechanism of Cam from M. thermophila, the archetype of the gamma-class, via a high resolution neutron structure and kinetic analysis of site-specific amino acid replacement variants. In the course of the investigation, goals were added to take advantage of discoveries on enzymes responding to oxidative stress.« less

Filamentous carbon particles for cleaning oil spills and method of production

DOEpatents

Muradov, Nazim

2010-04-06

A compact hydrogen generator is coupled to or integrated with a fuel cell for portable power applications. Hydrogen is produced via thermocatalytic decomposition (cracking, pyrolysis) of hydrocarbon fuels in oxidant-free environment. The apparatus can utilize a variety of hydrocarbon fuels, including natural gas, propane, gasoline, kerosene, diesel fuel, crude oil (including sulfurous fuels). The hydrogen-rich gas produced is free of carbon oxides or other reactive impurities, so it could be directly fed to any type of a fuel cell. The catalysts for hydrogen production in the apparatus are carbon-based or metal-based materials and doped, if necessary, with a sulfur-capturing agent. Additionally disclosed are two novel processes for the production of two types of carbon filaments, and a novel filamentous carbon product. The hydrogen generator can be conveniently integrated with high temperature fuel cells to produce an efficient and self-contained source of electrical power.

A mixing-model approach to quantifying sources of organic matter to salt marsh sediments

NASA Astrophysics Data System (ADS)

Bowles, K. M.; Meile, C. D.

2010-12-01

Salt marshes are highly productive ecosystems, where autochthonous production controls an intricate exchange of carbon and energy among organisms. The major sources of organic carbon to these systems include 1) autochthonous production by vascular plant matter, 2) import of allochthonous plant material, and 3) phytoplankton biomass. Quantifying the relative contribution of organic matter sources to a salt marsh is important for understanding the fate and transformation of organic carbon in these systems, which also impacts the timing and magnitude of carbon export to the coastal ocean. A common approach to quantify organic matter source contributions to mixtures is the use of linear mixing models. To estimate the relative contributions of endmember materials to total organic matter in the sediment, the problem is formulated as a constrained linear least-square problem. However, the type of data that is utilized in such mixing models, the uncertainties in endmember compositions and the temporal dynamics of non-conservative entitites can have varying affects on the results. Making use of a comprehensive data set that encompasses several endmember characteristics - including a yearlong degradation experiment - we study the impact of these factors on estimates of the origin of sedimentary organic carbon in a saltmarsh located in the SE United States. We first evaluate the sensitivity of linear mixing models to the type of data employed by analyzing a series of mixing models that utilize various combinations of parameters (i.e. endmember characteristics such as δ13COC, C/N ratios or lignin content). Next, we assess the importance of using more than the minimum number of parameters required to estimate endmember contributions to the total organic matter pool. Then, we quantify the impact of data uncertainty on the outcome of the analysis using Monte Carlo simulations and accounting for the uncertainty in endmember characteristics. Finally, as biogeochemical processes can alter endmember characteristics over time, we investigate the effect of early diagenesis on chosen parameters, an analysis that entails an assessment of the organic matter age distribution. Thus, estimates of the relative contributions of phytoplankton, C3 and C4 plants to bulk sediment organic matter depend not only on environmental characteristics that impact reactivity, but also on sediment mixing processes.

Modeling Source Water TOC Using Hydroclimate Variables and Local Polynomial Regression.

PubMed

Samson, Carleigh C; Rajagopalan, Balaji; Summers, R Scott

2016-04-19

To control disinfection byproduct (DBP) formation in drinking water, an understanding of the source water total organic carbon (TOC) concentration variability can be critical. Previously, TOC concentrations in water treatment plant source waters have been modeled using streamflow data. However, the lack of streamflow data or unimpaired flow scenarios makes it difficult to model TOC. In addition, TOC variability under climate change further exacerbates the problem. Here we proposed a modeling approach based on local polynomial regression that uses climate, e.g. temperature, and land surface, e.g., soil moisture, variables as predictors of TOC concentration, obviating the need for streamflow. The local polynomial approach has the ability to capture non-Gaussian and nonlinear features that might be present in the relationships. The utility of the methodology is demonstrated using source water quality and climate data in three case study locations with surface source waters including river and reservoir sources. The models show good predictive skill in general at these locations, with lower skills at locations with the most anthropogenic influences in their streams. Source water TOC predictive models can provide water treatment utilities important information for making treatment decisions for DBP regulation compliance under future climate scenarios.

Three alcohol dehydrogenase genes and one acetyl-CoA synthetase gene are responsible for ethanol utilization in Yarrowia lipolytica.

PubMed

Gatter, Michael; Ottlik, Stephanie; Kövesi, Zsolt; Bauer, Benjamin; Matthäus, Falk; Barth, Gerold

2016-10-01

The non-conventional yeast Yarrowia lipolytica is able to utilize a wide range of different substrates like glucose, glycerol, ethanol, acetate, proteins and various hydrophobic molecules. Although most metabolic pathways for the utilization of these substrates have been clarified by now, it was not clear whether ethanol is oxidized by alcohol dehydrogenases or by an alternative oxidation system inside the cell. In order to detect the genes that are required for ethanol utilization in Y. lipolytica, eight alcohol dehydrogenase (ADH) genes and one alcohol oxidase gene (FAO1) have been identified and respective deletion strains were tested for their ability to metabolize ethanol. As a result of this, we found that the availability of ADH1, ADH2 or ADH3 is required for ethanol utilization in Y. lipolytica. A strain with deletions in all three genes is lacking the ability to utilize ethanol as sole carbon source. Although Adh2p showed by far the highest enzyme activity in an in vitro assay, the availability of any of the three genes was sufficient to enable a decent growth. In addition to ADH1, ADH2 and ADH3, an acetyl-CoA synthetase encoding gene (ACS1) was found to be essential for ethanol utilization. As Y. lipolytica is a non-fermenting yeast, it is neither able to grow under anaerobic conditions nor to produce ethanol. To investigate whether Y. lipolytica may produce ethanol, the key genes of alcoholic fermentation in S. cerevisiae, ScADH1 and ScPDC1, were overexpressed in an ADH and an ACS1 deletion strain. However, instead of producing ethanol, the respective strains regained the ability to use ethanol as single carbon source and were still not able to grow under anaerobic conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

Synthesis of carbon nanostructures from high density polyethylene (HDPE) and polyethylene terephthalate (PET) waste by chemical vapour deposition

NASA Astrophysics Data System (ADS)

Hatta, M. N. M.; Hashim, M. S.; Hussin, R.; Aida, S.; Kamdi, Z.; Ainuddin, AR; Yunos, MZ

2017-10-01

In this study, carbon nanostructures were synthesized from High Density Polyethylene (HDPE) and Polyethylene terephthalate (PET) waste by single-stage chemical vapour deposition (CVD) method. In CVD, iron was used as catalyst and pyrolitic of carbon source was conducted at temperature 700, 800 and 900°C for 30 minutes. Argon gas was used as carrier gas with flow at 90 sccm. The synthesized carbon nanostructures were characterized by FESEM, EDS and calculation of carbon yield (%). FESEM micrograph shows that the carbon nanostructures were only grown as nanofilament when synthesized from PET waste. The synthesization of carbon nanostructure at 700°C was produced smooth and the smallest diameter nanofilament compared to others. The carbon yield of synthesized carbon nanostructures from PET was lower from HDPE. Furthermore, the carbon yield is recorded to increase with increasing of reaction temperature for all samples. Elemental study by EDS analysis were carried out and the formation of carbon nanostructures was confirmed after CVD process. Utilization of polymer waste to produce carbon nanostructures is beneficial to ensure that the carbon nanotechnology will be sustained in future.

Repeated-batch fermentations of xylose and glucose-xylose mixtures using a respiration-deficient Saccharomyces cerevisiae engineered for xylose metabolism.

PubMed

Kim, Soo Rin; Lee, Ki-Sung; Choi, Jin-Ho; Ha, Suk-Jin; Kweon, Dae-Hyuk; Seo, Jin-Ho; Jin, Yong-Su

2010-11-01

Xylose-fermenting Saccharomyces strains are needed for commercialization of ethanol production from lignocellulosic biomass. Engineered Saccharomyces cerevisiae strains expressing XYL1, XYL2 and XYL3 from Pichia stipitis, however, utilize xylose in an oxidative manner, which results in significantly lower ethanol yields from xylose as compared to glucose. As such, we hypothesized that reconfiguration of xylose metabolism from oxidative into fermentative manner might lead to efficient ethanol production from xylose. To this end, we generated a respiration-deficient (RD) mutant in order to enforce engineered S. cerevisiae to utilize xylose only through fermentative metabolic routes. Three different repeated-batch fermentations were performed to characterize characteristics of the respiration-deficient mutant. When fermenting glucose as a sole carbon source, the RD mutant exhibited near theoretical ethanol yields (0.46 g g(-1)) during repeated-batch fermentations by recycling the cells. As the repeated-batch fermentation progressed, the volumetric ethanol productivity increased (from 7.5 to 8.3 g L(-1)h(-1)) because of the increased biomass from previous cultures. On the contrary, the mutant showed decreasing volumetric ethanol productivities during the repeated-batch fermentations using xylose as sole carbon source (from 0.4 to 0.3 g L(-1)h(-1)). The mutant did not grow on xylose and lost fermenting ability gradually, indicating that the RD mutant cannot maintain a good fermenting ability on xylose as a sole carbon source. However, the RD mutant was capable of fermenting a mixture of glucose and xylose with stable yields (0.35 g g(-1)) and productivities (0.52 g L(-1)h(-1)) during the repeated-batch fermentation. In addition, ethanol yields from xylose during the mixed sugar fermentation (0.30 g g(-1)) were higher than ethanol yields from xylose as a sole carbon source (0.21 g g(-1)). These results suggest that a strategy for increasing ethanol yield through respiration-deficiency can be applied for the fermentation of lignocellulosic hydrolyzates containing glucose and xylose. Copyright © 2010 Elsevier B.V. All rights reserved.

Microbial lime-mud production and its relation to climate change

USGS Publications Warehouse

Yates, K.K.; Robbins, L.L.; Gerhard, L.C.; Harrison, W.E.; Hanson, B.M.B.

2001-01-01

Microbial calcification has been identified as a significant source of carbonate sediment production in modern marine and lacustrine environments around the globe. This process has been linked to the production of modern whitings and large, micritic carbonate deposits throughout the geologic record. Furthermore, carbonate deposits believed to be the result of cyanobacterial and microalgal calcification suggest that the potential exists for long-term preservation of microbial precipitates and storage of carbon dioxide (CO2). Recent research has advanced our understanding of the microbial-calcification mechanism as a photosynthetically driven process. However, little is known of the effects of this process on inorganic carbon cycling or of the effects of changing climate on microbial-calcification mechanisms.Laboratory experiments on microbial cellular physiology demonstrate that cyanobacteria and green algae can utilize different carbon species for metabolism and calcification. Cyanobacterial calcification relies on bicarbonate (HCO3–)utilization while green algae use primarily CO2. Therefore, depending on which carbonate species (HCO3– or CO2) dominates in the ocean or lacustrine environments (a condition ultimately linked to atmospheric partial pressure PCO2), the origin of lime-mud production by cyanobacteria and/or algae may fluctuate through geologic time. Trends of cyanobacteria versus algal dominance in the rock record corroborate this conclusion. These results suggest that relative species abundances of calcareous cyanobacteria and algae in the Phanerozoic may serve as potential proxies for assessing paleoclimatic conditions, including fluctuations in atmospheric PCO2.

Effect of Different Carbon Sources on Relative Growth Rate, Internal Carbohydrates, and Mannitol 1-Oxidoreductase Activity in Celery Suspension Cultures.

PubMed Central

Stoop, JMH.; Pharr, D. M.

1993-01-01

Little information exists concerning the biochemical route of mannitol catabolism in higher plant cells. In this study, the role of a recently discovered mannitol 1-oxidoreductase (MDH) in mannitol catabolism was investigated. Suspension cultures of celery (Apium graveolens L. var dulce [Mill.] Pers.) were successfully grown on nutrient media with either mannitol, mannose, or sucrose as the sole carbon source. Cell cultures grown on any of the three carbon sources did not differ in relative growth rate, as measured by packed cell volume, but differed drastically in internal carbohydrate concentration. Mannitol-grown cells contained high concentrations of mannitol and extremely low concentrations of sucrose, fructose, glucose, and mannose. Sucrose-grown cells had high concentrations of sucrose early in the growth cycle and contained a substantial hexose pool. Mannose-grown cells had a high mannose concentration early in the cycle, which decreased during the growth cycle, whereas their internal sucrose concentrations remained relatively constant during the entire growth cycle. Celery suspension cultures on all three carbon substrates contained an NAD-dependent MDH. Throughout the growth cycle, MDH activity was 2- to 4-fold higher in mannitol-grown cells compared with sucrose- or mannose-grown cells, which did not contain detectable levels of mannitol, indicating that MDH functions pre-dominantly in an oxidative capacity in situ. The MDH activity observed in celery cells was 3-fold higher than the minimum amount required to account for the observed rate of mannitol utilization from the media. Cultures transferred from mannitol to mannose underwent a decrease in MDH activity over a period of days, and transfer from mannose to mannitol resulted in an increase in MDH activity. These data provide strong evidence that MDH plays an important role in mannitol utilization in celery suspension cultures. PMID:12231996

Benthic foraminifera record and geochemical studies to reconstruct the recent (~400 ya) paleoenvironment of Tomales Bay, California

NASA Astrophysics Data System (ADS)

Flores, S. C.; Hill, T. M.; Russell, A. D.; Brooks, G.

2010-12-01

We are conducting investigations of calcareous benthic foraminifera acquired from Tomales Bay, California to reconstruct geochemical conditions of the bay for the past ~400 years, a time period of both natural and anthropogenic environmental change. Tomales Bay, located ~50km northwest of San Francisco, is a long (20.4 km), narrow (0.7 - 1.7 km) and shallow (2.0 - 6.0 m) bay that exhibits long-residence times and is stratified in the summer due to seasonal hypersalinity. Tomales Bay is a unique environment for climate and environmental change research because of the wide documented variability in carbonate parameters (pH, alkalinity, DIC) due to freshwater input from terrestrial sources that decreases aragonite and calcite saturation states. The historical record provided by benthic foraminiferal species and geochemistry, sedimentary carbon (TOC and TIC) analyses, and investigations of recent (Rose-Bengal stained) foraminifera are being utilized to constrain 3 major processes: 1) the range of temperature and salinity shifts over the past 400 years, 2) the relative dominance of marine- vs. fresh-water sources to the bay, and 3) the extent to which freshwater input and runoff may influence water chemistry (saturation state, Ω) with impacts on foraminiferal calcification. Four sediment cores were acquired in 2009 and 2010, and subsequently age-dated utilizing radiocarbon analyses (seven samples). Results indicate an increase in preservation of agglutinated versus calcareous foraminiferal tests (shells) since the mid-1900’s, and greater abundances of agglutinated tests found near freshwater sources. The major calcareous foraminifera present in the record include Elphidium hannai, Elphidium excavatum, Ammonia tepida, and Buccella frigida. Results from oxygen and carbon stable isotope analyses as well as total organic carbon (by weight) for all the cores will also be presented. These results will be compared to modern observations and instrumental records of temperature, salinity and pH variability to understand the context of historical changes compared to modern shifts due to human influence.

Biological degradation and composition of inedible sweetpotato biomass.

PubMed

Trotman, A A; Almazan, A M; Alexander, A D; Loretan, P A; Zhou, X; Lu, J Y

1996-01-01

Many challenges are presented by biological degradation in a bioregenerative Controlled Ecological Life Support System (CELSS) as envisioned by the U.S. National Aeronautics and Space Administration (NASA). In the studies conducted with biodegradative microorganism indigenous to sweetpotato fields, it was determined that a particle size of 75 microns and incubation temperature of 30 degrees C were optimal for degradation. The composition of the inedible biomass and characterization of plant nutrient solution indicated the presence of potential energy sources to drive microbial transformations of plant waste. Selected indigenous soil isolates with ligno-cellulolytic or sulfate-reducing ability were utilized in biological studies and demonstrated diversity in ability to reduce sulfate in solution and to utilize alternative carbon sources: a lignin analog--4-hydroxy, 3-methoxy cinnamic acid, cellulose, arabinose, glucose, sucrose, mannitol, galactose, ascorbic acid.

Few-layer graphene growth from polystyrene as solid carbon source utilizing simple APCVD method

NASA Astrophysics Data System (ADS)

Ahmadi, Shahrokh; Afzalzadeh, Reza

2016-07-01

This research article presents development of an economical, simple, immune and environment friendly process to grow few-layer graphene by controlling evaporation rate of polystyrene on copper foil as catalyst and substrate utilizing atmospheric pressure chemical vapor deposition (APCVD) method. Evaporation rate of polystyrene depends on molecular structure, amount of used material and temperature. We have found controlling rate of evaporation of polystyrene by controlling the source temperature is easier than controlling the material weight. Atomic force microscopy (AFM) as well as Raman Spectroscopy has been used for characterization of the layers. The frequency of G‧ to G band ratio intensity in some samples varied between 0.8 and 1.6 corresponding to few-layer graphene. Topography characterization by atomic force microscopy confirmed Raman results.

Biological degradation and composition of inedible sweetpotato biomass

NASA Technical Reports Server (NTRS)

Trotman, A. A.; Almazan, A. M.; Alexander, A. D.; Loretan, P. A.; Zhou, X.; Lu, J. Y.

1996-01-01

Many challenges are presented by biological degradation in a bioregenerative Controlled Ecological Life Support System (CELSS) as envisioned by the U.S. National Aeronautics and Space Administration (NASA). In the studies conducted with biodegradative microorganism indigenous to sweetpotato fields, it was determined that a particle size of 75 microns and incubation temperature of 30 degrees C were optimal for degradation. The composition of the inedible biomass and characterization of plant nutrient solution indicated the presence of potential energy sources to drive microbial transformations of plant waste. Selected indigenous soil isolates with ligno-cellulolytic or sulfate-reducing ability were utilized in biological studies and demonstrated diversity in ability to reduce sulfate in solution and to utilize alternative carbon sources: a lignin analog--4-hydroxy, 3-methoxy cinnamic acid, cellulose, arabinose, glucose, sucrose, mannitol, galactose, ascorbic acid.

Influence of Three Contrasting Detrital Carbon Sources on Planktonic Bacterial Metabolism in a Mesotrophic Lake.

PubMed

Wehr; Petersen; Findlay

1999-01-01

Abstract Lakes receive organic carbon from a diversity of sources which vary in their contribution to planktonic microbial food webs. We conducted a mesocosm study to test the effects of three different detrital carbon sources (algae, aquatic macrophytes, terrestrial leaves) on several measures of microbial metabolism in a small meso-eutrophic lake (DOC approximately 5 mg/L). Small DOC additions (DeltaC < 1 mg/L) affected bacterial numbers, growth, and pathways of carbon acquisition. Macrophyte and leaf detritus significantly increased TDP and color, but bacterial densities initially (+12 h) were unaffected. After 168 h, densities in systems amended with terrestrial detritus were 60% less than in controls, while production rates in mesocosms with macrophyte detritus were 4-fold greater. Detritus treatments resulted in greater per-cell production rates either through stable cell numbers and greater growth rates (macrophyte-C) or lower densities with stable production rates (terrestrial-C). After only 12 h, rates of leucine aminopeptidase (LAPase) activity were 2.5x greater in macrophyte-C systems than in controls, but LAPase and beta-N-acetylglucosamindase activities in systems amended with terrestrial-C were only 50% of rates in controls. After 168 h, beta-xylosidase rates were significantly greater in communities with terrestrial and phytoplankton detritus. Microbial utilization of >20% of 102 carbon sources tested were affected by at least one detritus addition. Macrophyte-C had positive (6% of substrates) and negative (14%) effects on substrate use; terrestrial detritus had mainly positive effects. An ordination based on carbon-use profiles (+12 h) revealed a cluster of macrophyte-amended communities with greater use of psicose, lactulose, and succinamic acid; controls and algal-detritus systems were more effective in metabolizing two common sugars and cellobiose. After 168 h, communities receiving terrestrial detritus were most tightly clustered, exhibiting greater use of raffinose, pyroglutamic acid, and sebacic acid. Results suggest that pelagic bacterial communities respond to changes in organic carbon source rapidly and by different routes, including shifts in per-cell production rates and variations in degradation of a variety of compounds comprising the DOC pool.

GPR-4 Is a Predicted G-Protein-Coupled Receptor Required for Carbon Source-Dependent Asexual Growth and Development in Neurospora crassa

PubMed Central

Li, Liande; Borkovich, Katherine A.

2006-01-01

The filamentous fungus Neurospora crassa is able to utilize a wide variety of carbon sources. Here, we examine the involvement of a predicted G-protein-coupled receptor (GPCR), GPR-4, during growth and development in the presence of different carbon sources in N. crassa. Δgpr-4 mutants have reduced mass accumulation compared to the wild type when cultured on high levels of glycerol, mannitol, or arabinose. The defect is most severe on glycerol and is cell density dependent. The genetic and physical relationship between GPR-4 and the three N. crassa Gα subunits (GNA-1, GNA-2, and GNA-3) was explored. All three Gα mutants are defective in mass accumulation when cultured on glycerol. However, the phenotypes of Δgna-1 and Δgpr-4 Δgna-1 mutants are identical, introduction of a constitutively activated gna-1 allele suppresses the defects of the Δgpr-4 mutation, and the carboxy terminus of GPR-4 interacts most strongly with GNA-1 in the yeast two-hybrid assay. Although steady-state cyclic AMP (cAMP) levels are normal in Δgpr-4 strains, exogenous cAMP partially remediates the dry mass defects of Δgpr-4 mutants on glycerol medium and Δgpr-4 strains lack the transient increase in cAMP levels observed in the wild type after addition of glucose to glycerol-grown liquid cultures. Our results support the hypothesis that GPR-4 is coupled to GNA-1 in a cAMP signaling pathway that regulates the response to carbon source in N. crassa. GPR-4-related GPCRs are present in the genomes of several filamentous ascomycete fungal pathogens, raising the possibility that a similar pathway regulates carbon sensing in these organisms. PMID:16896213

Evaporation induced 18O and 13C enrichment in lake systems: A global perspective on hydrologic balance effects

NASA Astrophysics Data System (ADS)

Horton, Travis W.; Defliese, William F.; Tripati, Aradhna K.; Oze, Christopher

2016-01-01

Growing pressure on sustainable water resource allocation in the context of global development and rapid environmental change demands rigorous knowledge of how regional water cycles change through time. One of the most attractive and widely utilized approaches for gaining this knowledge is the analysis of lake carbonate stable isotopic compositions. However, endogenic carbonate archives are sensitive to a variety of natural processes and conditions leaving isotopic datasets largely underdetermined. As a consequence, isotopic researchers are often required to assume values for multiple parameters, including temperature of carbonate formation or lake water δ18O, in order to interpret changes in hydrologic conditions. Here, we review and analyze a global compilation of 57 lacustrine dual carbon and oxygen stable isotope records with a topical focus on the effects of shifting hydrologic balance on endogenic carbonate isotopic compositions. Through integration of multiple large datasets we show that lake carbonate δ18O values and the lake waters from which they are derived are often shifted by >+10‰ relative to source waters discharging into the lake. The global pattern of δ18O and δ13C covariation observed in >70% of the records studied and in several evaporation experiments demonstrates that isotopic fractionations associated with lake water evaporation cause the heavy carbon and oxygen isotope enrichments observed in most lakes and lake carbonate records. Modeled endogenic calcite compositions in isotopic equilibrium with lake source waters further demonstrate that evaporation effects can be extreme even in lake records where δ18O and δ13C covariation is absent. Aridisol pedogenic carbonates show similar isotopic responses to evaporation, and the relevance of evaporative modification to paleoclimatic and paleotopographic research using endogenic carbonate proxies are discussed. Recent advances in stable isotope research techniques present unprecedented opportunities to overcome the underdetermined nature of stable isotopic data through integration of multiple isotopic proxies, including dual element 13C-excess values and clumped isotope temperature estimates. We demonstrate the utility of applying these multi-proxy approaches to the interpretation of paleohydroclimatic conditions in ancient lake systems. Understanding past, present, and future hydroclimatic systems is a global imperative. Significant progress should be expected as these modern research techniques become more widely applied and integrated with traditional stable isotopic proxies.

Chitin utilization by the insect-transmitted bacterium Xylella fastidiosa.

PubMed

Killiny, Nabil; Prado, Simone S; Almeida, Rodrigo P P

2010-09-01

Xylella fastidiosa is an insect-borne bacterium that colonizes xylem vessels of a large number of host plants, including several crops of economic importance. Chitin is a polysaccharide present in the cuticle of leafhopper vectors of X. fastidiosa and may serve as a carbon source for this bacterium. Biological assays showed that X. fastidiosa reached larger populations in the presence of chitin. Additionally, chitin induced phenotypic changes in this bacterium, notably increasing adhesiveness. Quantitative PCR assays indicated transcriptional changes in the presence of chitin, and an enzymatic assay demonstrated chitinolytic activity by X. fastidiosa. An ortholog of the chitinase A gene (chiA) was identified in the X. fastidiosa genome. The in silico analysis revealed that the open reading frame of chiA encodes a protein of 351 amino acids with an estimated molecular mass of 40 kDa. chiA is in a locus that consists of genes implicated in polysaccharide degradation. Moreover, this locus was also found in the genomes of closely related bacteria in the genus Xanthomonas, which are plant but not insect associated. X. fastidiosa degraded chitin when grown on a solid chitin-yeast extract-agar medium and grew in liquid medium with chitin as the sole carbon source; ChiA was also determined to be secreted. The gene encoding ChiA was cloned into Escherichia coli, and endochitinase activity was detected in the transformant, showing that the gene is functional and involved in chitin degradation. The results suggest that X. fastidiosa may use its vectors' foregut surface as a carbon source. In addition, chitin may trigger X. fastidiosa's gene regulation and biofilm formation within vectors. Further work is necessary to characterize the role of chitin and its utilization in X. fastidiosa.

Chitin Utilization by the Insect-Transmitted Bacterium Xylella fastidiosa▿ †

PubMed Central

Killiny, Nabil; Prado, Simone S.; Almeida, Rodrigo P. P.

2010-01-01

Xylella fastidiosa is an insect-borne bacterium that colonizes xylem vessels of a large number of host plants, including several crops of economic importance. Chitin is a polysaccharide present in the cuticle of leafhopper vectors of X. fastidiosa and may serve as a carbon source for this bacterium. Biological assays showed that X. fastidiosa reached larger populations in the presence of chitin. Additionally, chitin induced phenotypic changes in this bacterium, notably increasing adhesiveness. Quantitative PCR assays indicated transcriptional changes in the presence of chitin, and an enzymatic assay demonstrated chitinolytic activity by X. fastidiosa. An ortholog of the chitinase A gene (chiA) was identified in the X. fastidiosa genome. The in silico analysis revealed that the open reading frame of chiA encodes a protein of 351 amino acids with an estimated molecular mass of 40 kDa. chiA is in a locus that consists of genes implicated in polysaccharide degradation. Moreover, this locus was also found in the genomes of closely related bacteria in the genus Xanthomonas, which are plant but not insect associated. X. fastidiosa degraded chitin when grown on a solid chitin-yeast extract-agar medium and grew in liquid medium with chitin as the sole carbon source; ChiA was also determined to be secreted. The gene encoding ChiA was cloned into Escherichia coli, and endochitinase activity was detected in the transformant, showing that the gene is functional and involved in chitin degradation. The results suggest that X. fastidiosa may use its vectors' foregut surface as a carbon source. In addition, chitin may trigger X. fastidiosa's gene regulation and biofilm formation within vectors. Further work is necessary to characterize the role of chitin and its utilization in X. fastidiosa. PMID:20656858

Utilization of shallow-water seagrass detritus by Carribbean deep-sea macrofauna: δ 13C evidence

NASA Astrophysics Data System (ADS)

Suchanek, Thomas H.; Williams, Susan L.; Ogden, John C.; Hubbard, Dennis K.; Gill, Ivan P.

1985-02-01

Three dives were made using the DSRV Alvin in the deep-sea basin north of St. Croix, Virgin Islands. Detrital seagrasses and macrofaunal distributions at 2455 to 3950 m depth were assessed quantitatively. Counts of the manatee grass Syringodium filiforme ( ca. 5 to 100 blades m -2) contrasted sharply with those of the turtle grass Thalassia testudinum ( ca. 0.1 to 2.0 blades m -2), reflecting an abundance proportional to previously reported export rates of the same species from Tague Bay, a nearby shallow source lagoon. Of the macrofaunal consumers that could potentially utilize this detrital nutrient source, three species of holothurians ( Mesothuria verrilli, Psychropotes semperiana, and Benthodytes linqua) and two species of sea urchins ( Hygrosoma petersi and Salencidaris profundi) were collected and/or observed. Gut content analyses revealed that all three holothurians deposit-feed on sediment and at least one species of sea urchin ( H. petersi) feeds almost exclusively on Syringodium. Carbon: nitrogen analyses of naturally occurring abyssal Thalassia detritus showed very low nitrogen content (0.21% N) and a high C:N ratio (214.8), thus yielding a loo nutritional value. Fresh Thalassia blades held in a litter bag experiment (by R. D. Turner) at 3950 m changed little in nitrogen content and C:N ratio after four years. A comparison was made of the stable carbon isotope ratios of 13C: 12C for abyssal seagrass detritus and other potential carbon sources with those for tissues from the holothurian and urchin consumers. The results indicate that a significant proportion of the nutrition of both groups is derived from detrital seagrasses either by direct consumption (sea urchins) or indirectly by deposit-feeding on sediments enriched by decomposed seagrasses (holothurians).

Genome Sequence of Arenibacter algicola Strain TG409, a Hydrocarbon-Degrading Bacterium Associated with Marine Eukaryotic Phytoplankton

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutierrez, Tony; Whitman, William B.; Huntemann, Marcel

Arenibacter algicolastrain TG409 was isolated fromSkeletonema costatumand exhibits the ability to utilize polycyclic aromatic hydrocarbons as sole sources of carbon and energy. Here, we present the genome sequence of this strain, which is 5,550,230 bp with 4,722 genes and an average G+C content of 39.7%.

Genome Sequence of Arenibacter algicola Strain TG409, a Hydrocarbon-Degrading Bacterium Associated with Marine Eukaryotic Phytoplankton

DOE PAGES

Gutierrez, Tony; Whitman, William B.; Huntemann, Marcel; ...

2016-08-04

Arenibacter algicolastrain TG409 was isolated fromSkeletonema costatumand exhibits the ability to utilize polycyclic aromatic hydrocarbons as sole sources of carbon and energy. Here, we present the genome sequence of this strain, which is 5,550,230 bp with 4,722 genes and an average G+C content of 39.7%.

Characterization of arsenite-oxidizing bacteria to decipher their role in arsenic bioremediation.

PubMed

Biswas, Rimi; Sarkar, Angana

2018-06-11

High arsenic groundwater contamination causes serious health risks in many developing countries, particularly in India and Bangladesh. The arsenic fluxes in aquifers are primarily controlled by bacterial populations through biogeochemical cycle. In this present study, two gram-positive rod-shaped bacteria were isolated from shallow aquifers of Bhojpur district in Bihar during the early winter season, able to withstand arsenite (As 3+ ) concentration upto 70 mM and 1000 mM of arsenate (As 5+ ) concentration. They showed high resistance to heavy metals up to 30 mM and utilized some complex sugars along with different carbon sources. Growth at wide range of temperature, pH and salinity were observed. Both these isolates showed high efficiency in converting As 3+ into less toxic concentrations of As 5+ respectively from arsenic enriched culture media. Along with superior arsenic transformation and arsenic resistance abilities, the isolates showed a wide variety of metabolic capacity in terms of utilizing a variety of carbon sources under aerobic conditions, respectively. This study reports the potential As 3+ -oxidizing bacteria that can play an important role in subsurface arsenic transformation that will aid in designing future bioremediation strategy for the arsenic affected areas.

Assessment of self-organizing maps to analyze sole-carbon source utilization profiles.

PubMed

Leflaive, Joséphine; Céréghino, Régis; Danger, Michaël; Lacroix, Gérard; Ten-Hage, Loïc

2005-07-01

The use of community-level physiological profiles obtained with Biolog microplates is widely employed to consider the functional diversity of bacterial communities. Biolog produces a great amount of data which analysis has been the subject of many studies. In most cases, after some transformations, these data were investigated with classical multivariate analyses. Here we provided an alternative to this method, that is the use of an artificial intelligence technique, the Self-Organizing Maps (SOM, unsupervised neural network). We used data from a microcosm study of algae-associated bacterial communities placed in various nutritive conditions. Analyses were carried out on the net absorbances at two incubation times for each substrates and on the chemical guild categorization of the total bacterial activity. Compared to Principal Components Analysis and cluster analysis, SOM appeared as a valuable tool for community classification, and to establish clear relationships between clusters of bacterial communities and sole-carbon sources utilization. Specifically, SOM offered a clear bidimensional projection of a relatively large volume of data and were easier to interpret than plots commonly obtained with multivariate analyses. They would be recommended to pattern the temporal evolution of communities' functional diversity.

Biodegradation of polyethylene by the thermophilic bacterium Brevibacillus borstelensis.

PubMed

Hadad, D; Geresh, S; Sivan, A

2005-01-01

To select a polyethylene-degrading micro-organism and to study the factors affecting its biodegrading activity. A thermophilic bacterium Brevibaccillus borstelensis strain 707 (isolated from soil) utilized branched low-density polyethylene as the sole carbon source and degraded it. Incubation of polyethylene with B. borstelensis (30 days, 50 degrees C) reduced its gravimetric and molecular weights by 11 and 30% respectively. Brevibaccillus borstelensis also degraded polyethylene in the presence of mannitol. Biodegradation of u.v. photo-oxidized polyethylene increased with increasing irradiation time. Fourier Transform Infra-Red (FTIR) analysis of photo-oxidized polyethylene revealed a reduction in carbonyl groups after incubation with the bacteria. This study demonstrates that polyethylene--considered to be inert--can be biodegraded if the right microbial strain is isolated. Enrichment culture methods were effective for isolating a thermophilic bacterium capable of utilizing polyethylene as the sole carbon and energy source. Maximal biodegradation was obtained in combination with photo-oxidation, which showed that carbonyl residues formed by photo-oxidation play a role in biodegradation. Brevibaccillus borstelensis also degraded the CH2 backbone of nonirradiated polyethylene. Biodegradation of polyethylene by a single bacterial strain contributes to our understanding of the process and the factors affecting polyethylene biodegradation.

Glycerol metabolism and transport in yeast and fungi: established knowledge and ambiguities.

PubMed

Klein, Mathias; Swinnen, Steve; Thevelein, Johan M; Nevoigt, Elke

2017-03-01

There is huge variability among yeasts with regard to their efficiency in utilizing glycerol as the sole source of carbon and energy. Certain species show growth rates with glycerol comparable to those reached with glucose as carbon source; others are virtually unable to utilize glycerol, especially in synthetic medium. Most of our current knowledge regarding glycerol uptake and catabolic pathways has been gained from studying laboratory strains of the model yeast Saccharomyces cerevisiae. The growth of these strains on glycerol is dependent on the presence of medium supplements such as amino acids and nucleobases. In contrast, there is only fragmentary knowledge about S. cerevisiae isolates able to grow in synthetic glycerol medium without such supplements as well as about growth of non-Saccharomyces yeast species on glycerol. Thus, more research is required to understand why certain strains and species show superior growth performance on glycerol compared with common S. cerevisiae laboratory strains. This mini-review summarizes what is known so far about the gene products and pathways involved in glycerol metabolism and transport in yeast and fungi as well as the regulation of these processes. © 2016 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Comparative Metabolomics of Mycoplasma bovis and Mycoplasma gallisepticum Reveals Fundamental Differences in Active Metabolic Pathways and Suggests Novel Gene Annotations.

PubMed

Masukagami, Y; De Souza, D P; Dayalan, S; Bowen, C; O'Callaghan, S; Kouremenos, K; Nijagal, B; Tull, D; Tivendale, K A; Markham, P F; McConville, M J; Browning, G F; Sansom, F M

2017-01-01

Mycoplasmas are simple, but successful parasites that have the smallest genome of any free-living cell and are thought to have a highly streamlined cellular metabolism. Here, we have undertaken a detailed metabolomic analysis of two species, Mycoplasma bovis and Mycoplasma gallisepticum , which cause economically important diseases in cattle and poultry, respectively. Untargeted gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry analyses of mycoplasma metabolite extracts revealed significant differences in the steady-state levels of many metabolites in central carbon metabolism, while 13 C stable isotope labeling studies revealed marked differences in carbon source utilization. These data were mapped onto in silico metabolic networks predicted from genome wide annotations. The analyses elucidated distinct differences, including a clear difference in glucose utilization, with a marked decrease in glucose uptake and glycolysis in M. bovis compared to M. gallisepticum , which may reflect differing host nutrient availabilities. The 13 C-labeling patterns also revealed several functional metabolic pathways that were previously unannotated in these species, allowing us to assign putative enzyme functions to the products of a number of genes of unknown function, especially in M. bovis . This study demonstrates the considerable potential of metabolomic analyses to assist in characterizing significant differences in the metabolism of different bacterial species and in improving genome annotation. IMPORTANCE Mycoplasmas are pathogenic bacteria that cause serious chronic infections in production animals, resulting in considerable losses worldwide, as well as causing disease in humans. These bacteria have extremely reduced genomes and are thought to have limited metabolic flexibility, even though they are highly successful persistent parasites in a diverse number of species. The extent to which different Mycoplasma species are capable of catabolizing host carbon sources and nutrients, or synthesizing essential metabolites, remains poorly defined. We have used advanced metabolomic techniques to identify metabolic pathways that are active in two species of Mycoplasma that infect distinct hosts (poultry and cattle). We show that these species exhibit marked differences in metabolite steady-state levels and carbon source utilization. This information has been used to functionally characterize previously unknown genes in the genomes of these pathogens. These species-specific differences are likely to reflect important differences in host nutrient levels and pathogenic mechanisms.

Biological conversion of carbon dioxide and hydrogen into liquid fuels and industrial chemicals.

PubMed

Hawkins, Aaron S; McTernan, Patrick M; Lian, Hong; Kelly, Robert M; Adams, Michael W W

2013-06-01

Non-photosynthetic routes for biological fixation of carbon dioxide into valuable industrial chemical precursors and fuels are moving from concept to reality. The development of 'electrofuel'-producing microorganisms leverages techniques in synthetic biology, genetic and metabolic engineering, as well as systems-level multi-omic analysis, directed evolution, and in silico modeling. Electrofuel processes are being developed for a range of microorganisms and energy sources (e.g. hydrogen, formate, electricity) to produce a variety of target molecules (e.g. alcohols, terpenes, alkenes). This review examines the current landscape of electrofuel projects with a focus on hydrogen-utilizing organisms covering the biochemistry of hydrogenases and carbonic anhydrases, kinetic and energetic analyses of the known carbon fixation pathways, and the state of genetic systems for current and prospective electrofuel-producing microorganisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

Raw sugarcane bagasse as carbon source for xylanase production by Paenibacillus species: a potential degrader of agricultural wastes.

PubMed

Di Marco, Enzo; Soraire, Pablo M; Romero, Cintia M; Villegas, Liliana B; Martínez, María Alejandra

2017-08-01

Paenibacillus species isolated from a variety of natural sources have shown to be important glycoside hydrolases producers. These enzymes play a key role in bio-refining applications, as they are central biocatalysts for the processing of different types of polymers from vegetal biomass. Xylanase production by three native isolates belonging to the genus Paenibacillus was approached by utilizing mineral-based medium and agricultural by-products as a convenient source to produce biocatalysts suitable for their degradation. While varieties of alkali pretreated sugarcane bagasse were useful substrates for the strains from Paenibacillus genus evaluated, raw sugarcane bagasse was the most effective substrate for endoxylanase production by Paenibacillus sp. AR247. This strain was then selected to further improvement of its enzyme production by means of a two-step statistical approach. It was determined that the carbon source, provided as an inexpensive agro-waste, as well as phosphate and magnesium were the culture media components that most influenced the enzyme production, which was improved three times compared to the screening results.

New Pseudomonad Utilizing Methanol for Growth

PubMed Central

Chalfan, Y.; Mateles, R. I.

1972-01-01

A bacterium capable of rapid growth on methanol as sole carbon source was isolated and classified as a new pseudomonad. Its doubling time was about 100 min at 32 to 37 C, and it grew well at methanol concentrations up to 2%. The organism was sensitive to phosphate, but reasonable cell densities could be obtained by using pH control. Cell yields of about 31%, based on methanol consumed, were obtained. The amino acid pattern of the protein indicated that the bacterium holds promise as a source of single-cell protein. Images PMID:4110421

Engineering of Corynebacterium glutamicum for growth and succinate production from levoglucosan, a pyrolytic sugar substrate.

PubMed

Kim, Eun-Mi; Um, Youngsoon; Bott, Michael; Woo, Han Min

2015-10-01

Thermochemical processing provides continuous production of bio-oils from lignocellulosic biomass. Levoglucosan, a pyrolytic sugar substrate C6H10O5 in a bio-oil, has been used for ethanol production using engineered Escherichia coli. Here we provide the first example for succinate production from levoglucosan with Corynebacterium glutamicum, a well-known industrial amino acid producer. Heterologous expression of a gene encoding a sugar kinase from Lipomyces starkeyi, Gibberella zeae or Pseudomonas aeruginosa was employed for levoglucosan conversion in C. glutamicum because the wild type was unable to utilize levoglucosan as sole carbon source. As result, expression of a levoglucosan kinase (LGK) of L. starkeyi only enabled growth with levoglucosan as sole carbon source in CgXII minimal medium by catalyzing conversion of levoglucosan to glucose-6-phosphate. Subsequently, the lgk gene was expressed in an aerobic succinate producer of C. glutamicum, strain BL-1. The recombinant strain showed a higher succinate yield (0.25 g g(-1)) from 2% (w/v) levoglucosan than the reference strain BL-1 from 2% (w/v) glucose (0.19 g g(-1)), confirming that levoglucosan is an attractive carbon substrate for C. glutamicum producer strains. In summary, we demonstrated that a pyrolytic sugar could be a potential carbon source for microbial cell factories. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

D-Lactic acid production by Sporolactobacillus inulinus YBS1-5 with simultaneous utilization of cottonseed meal and corncob residue.

PubMed

Bai, Zhongzhong; Gao, Zhen; Sun, Junfei; Wu, Bin; He, Bingfang

2016-05-01

d-Lactic acid, is an important organic acid produced from agro-industrial wastes by Sporolactobacillus inulinus YBS1-5 was investigated to reduce the raw material cost of fermentation. The YBS1-5 strain could produce d-lactic acid by using cottonseed meal as the sole nitrogen source. For efficient utilization, the cottonseed meal was enzymatically hydrolyzed and simultaneously utilized during d-lactic acid fermentation. Corncob residues are rich in cellulose and can be enzymatically hydrolyzed without pretreatment. The hydrolysate of this lignocellulosic waste could be utilized by strain YBS1-5 as a carbon source for d-lactic acid production. Under optimal conditions, a high d-lactic acid concentration (107.2g/L) was obtained in 7-L fed-batch fermenter, with an average productivity of 1.19g/L/h and a yield of 0.85g/g glucose. The optical purity of d-lactic acid in the broth was 99.2%. This study presented a new approach for low-cost production of d-lactic acid for an industrial application. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gas Fermentation-A Flexible Platform for Commercial Scale Production of Low-Carbon-Fuels and Chemicals from Waste and Renewable Feedstocks.

PubMed

Liew, FungMin; Martin, Michael E; Tappel, Ryan C; Heijstra, Björn D; Mihalcea, Christophe; Köpke, Michael

2016-01-01

There is an immediate need to drastically reduce the emissions associated with global fossil fuel consumption in order to limit climate change. However, carbon-based materials, chemicals, and transportation fuels are predominantly made from fossil sources and currently there is no alternative source available to adequately displace them. Gas-fermenting microorganisms that fix carbon dioxide (CO2) and carbon monoxide (CO) can break this dependence as they are capable of converting gaseous carbon to fuels and chemicals. As such, the technology can utilize a wide range of feedstocks including gasified organic matter of any sort (e.g., municipal solid waste, industrial waste, biomass, and agricultural waste residues) or industrial off-gases (e.g., from steel mills or processing plants). Gas fermentation has matured to the point that large-scale production of ethanol from gas has been demonstrated by two companies. This review gives an overview of the gas fermentation process, focusing specifically on anaerobic acetogens. Applications of synthetic biology and coupling gas fermentation to additional processes are discussed in detail. Both of these strategies, demonstrated at bench-scale, have abundant potential to rapidly expand the commercial product spectrum of gas fermentation and further improve efficiencies and yields.

Evaluating the efficiency of carbon utilisation via bioenergetics between biological aerobic and denitrifying phosphorus removal systems

PubMed Central

Jin, Zhan; He, Yin; Xu, Xuan; Zheng, Xiang-yong

2017-01-01

There are two biological systems available for removing phosphorus from waste water, conventional phosphorus removal (CPR) and denitrifying phosphorus removal (DPR) systems, and each is characterized by the type of sludge used in the process. In this study, we compared the characteristics associated with the efficiency of carbon utilization between CPR and DPR sludge using acetate as a carbon source. For DPR sludge, the heat emitted during the phosphorus release and phosphorus uptake processes were 45.79 kJ/mol e- and 84.09 kJ/mol e-, respectively. These values were about 2 fold higher than the corresponding values obtained for CPR sludge, suggesting that much of the energy obtained from the carbon source was emitted as heat. Further study revealed a smaller microbial mass within the DPR sludge compared to CPR sludge, as shown by a lower sludge yield coefficient (0.05 gVSS/g COD versus 0.36 gVSS/g COD), a result that was due to the lower energy capturing efficiency of DPR sludge according to bioenergetic analysis. Although the efficiency of anoxic phosphorus removal was only 39% the efficiency of aerobic phosphorus removal, the consumption of carbon by DPR sludge was reduced by 27.8% compared to CPR sludge through the coupling of denitrification with dephosphatation. PMID:29065157

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, B.D.; Apel, W.A.; Walton, M.R.

Conceptually, biofilters are vapor phase bioreactors that rely on microorganisms in the bed medium to oxidize contaminants in off-gases flowing through the bed to less hazardous compounds. In the most studied and utilized systems reduced compounds such as fuel hydrocarbons are enzymatically oxidized to compounds such as carbon dioxide and water. In these types of reactions the microorganisms in the bed oxidize the contaminant and transfer the electrons to oxygen which is the terminal electron acceptor in the process. In essence the contaminant is the carbon and energy source for the microorganisms in the bed medium and through this catabolicmore » process oxygen is reduced to water. An example of this oxidation process can be seen during the degradation of benzene and similar aromatic compounds. Aromatics are initially attacked by a dioxygenase enzyme which oxidizes the compounds to a labile dihydrodiole which is spontaneously converted to a catechol. The dihydroxylated aromatic rings is then opened by oxidative {open_quotes}ortho{close_quotes} or {open_quotes}meta{close_quotes} cleavage yielding cis, cis-muconic acid or 2-hydroxy-cis, cis-muconic semialdehyde, respectively. These organic compounds are further oxidized to carbon dioxide or are assimilated for cellular material. This paper describes the conversion of carbon tetrachloride using methanol as the primary carbon and energy source.« less

Gas Fermentation—A Flexible Platform for Commercial Scale Production of Low-Carbon-Fuels and Chemicals from Waste and Renewable Feedstocks

PubMed Central

Liew, FungMin; Martin, Michael E.; Tappel, Ryan C.; Heijstra, Björn D.; Mihalcea, Christophe; Köpke, Michael

2016-01-01

There is an immediate need to drastically reduce the emissions associated with global fossil fuel consumption in order to limit climate change. However, carbon-based materials, chemicals, and transportation fuels are predominantly made from fossil sources and currently there is no alternative source available to adequately displace them. Gas-fermenting microorganisms that fix carbon dioxide (CO2) and carbon monoxide (CO) can break this dependence as they are capable of converting gaseous carbon to fuels and chemicals. As such, the technology can utilize a wide range of feedstocks including gasified organic matter of any sort (e.g., municipal solid waste, industrial waste, biomass, and agricultural waste residues) or industrial off-gases (e.g., from steel mills or processing plants). Gas fermentation has matured to the point that large-scale production of ethanol from gas has been demonstrated by two companies. This review gives an overview of the gas fermentation process, focusing specifically on anaerobic acetogens. Applications of synthetic biology and coupling gas fermentation to additional processes are discussed in detail. Both of these strategies, demonstrated at bench-scale, have abundant potential to rapidly expand the commercial product spectrum of gas fermentation and further improve efficiencies and yields. PMID:27242719

Carbaryl degradation by bacterial isolates from a soil ecosystem of the Gaza Strip

PubMed Central

Hamada, Mazen; Matar, Ammar; Bashir, Abdallah

2015-01-01

Abstract Carbaryl is an important and widely used insecticide that pollutes soil and water systems. Bacteria from the local soil ecosystem of the Gaza Strip capable of utilizing carbaryl as the sole source of carbon and nitrogen were isolated and identified as belonging to Bacillus, Morganella, Pseudomonas, Aeromonas and Corynebacterium genera. Carbaryl biodegradation by Bacillus, Morganella and Corynebacterium isolates was analyzed in minimal liquid media supplemented with carbaryl as the only source of carbon and nitrogen. Bacillus and Morganella exhibited 94.6% and 87.3% carbaryl degradation, respectively, while Corynebacterium showed only moderate carbaryl degradation at 48.8%. These results indicate that bacterial isolates from a local soil ecosystem in the Gaza Strip are able to degrade carbaryl and can be used to decrease the risk of environmental contamination by this insecticide. PMID:26691466

Sustainable microalgae for the simultaneous synthesis of carbon quantum dots for cellular imaging and porous carbon for CO2 capture.

PubMed

Guo, Li-Ping; Zhang, Yan; Li, Wen-Cui

2017-05-01

Microalgae biomass is a sustainable source with the potential to produce a range of products. However, there is currently a lack of practical and functional processes to enable the high-efficiency utilization of the microalgae. We report here a hydrothermal process to maximize the utilizability of microalgae biomass. Specifically, our concept involves the simultaneous conversion of microalgae to (i) hydrophilic and stable carbon quantum dots and (ii) porous carbon. The synthesis is easily scalable and eco-friendly. The microalgae-derived carbon quantum dots possess a strong two-photon fluorescence property, have a low cytotoxicity and an efficient cellular uptake, and show potential for high contrast bioimaging. The microalgae-based porous carbons show excellent CO 2 capture capacities of 6.9 and 4.2mmolg -1 at 0 and 25°C respectively, primarily due to the high micropore volume (0.59cm 3 g -1 ) and large specific surface area (1396m 2 g -1 ). Copyright © 2017 Elsevier Inc. All rights reserved.

Facile Synthesis of Carbon-Coated Spinel Li4Ti5O12/Rutile-TiO2 Composites as an Improved Anode Material in Full Lithium-Ion Batteries with LiFePO4@N-Doped Carbon Cathode.

PubMed

Wang, Ping; Zhang, Geng; Cheng, Jian; You, Ya; Li, Yong-Ke; Ding, Cong; Gu, Jiang-Jiang; Zheng, Xin-Sheng; Zhang, Chao-Feng; Cao, Fei-Fei

2017-02-22

The spinel Li 4 Ti 5 O 12 /rutile-TiO 2 @carbon (LTO-RTO@C) composites were fabricated via a hydrothermal method combined with calcination treatment employing glucose as carbon source. The carbon coating layer and the in situ formed rutile-TiO 2 can effectively enhance the electric conductivity and provide quick Li + diffusion pathways for Li 4 Ti 5 O 12 . When used as an anode material for lithium-ion batteries, the rate capability and cycling stability of LTO-RTO@C composites were improved in comparison with those of pure Li 4 Ti 5 O 12 or Li 4 Ti 5 O 12 /rutile-TiO 2 . Moreover, the potential of approximately 1.8 V rechargeable full lithium-ion batteries has been achieved by utilizing an LTO-RTO@C anode and a LiFePO 4 @N-doped carbon cathode.

Progress Report on PICA Activities in Support of New Frontiers Missions

NASA Technical Reports Server (NTRS)

Stackpoole, Margaret; Venkatapathy, Ethiraj; Violette, Steve

2017-01-01

Phenolic Impregnated Carbon Ablator (PICA) is a TPS material that has been used in a number of previous flight missions (Stardust, MSL) and is planned for a number of future missions (OSIRIS-Rex and Mars 2020) so it has substantial flight heritage, is applicable to a wide range of missions, and is often baselined as the TPS in future NASA proposal activities. As is common with a number of TPS materials, PICA faces a supply chain issue with the rayon precursor from which the carbon fibers used in the PICA preform are derived. PICA uses a non-woven form of the rayon, which once carbonized, is used in the low-density carbon FiberForm (carbon tile) preform utilized in PICA. Current PICA uses a NASA-qualified non-domestic rayon supplier (Sniace), however the qualified supplier is no longer manufacturing the rayon materials. This activity will address PICA sustainability, by initially carbonizing the remaining stockpile of Sniace rayon precursor. A additional FiberForm manufacturing task from alternate rayon sources is also in progress.

Intrinsic activation: the relationship between biomass inorganic content and porosity formation during pyrolysis.

PubMed

Stratford, James P; Hutchings, Tony R; de Leij, Frans A A M

2014-05-01

The utility of pyrolytic carbons is closely related to their porosity and surface area, there is a clear benefit to the development of biomass pyrolysis processes which produce highly porous carbons. The results presented in this work demonstrate that by using biomass precursors with high inorganic content along with specified process conditions, carbons can be consistently produced with specific surface areas between 900 and 1600 m(2)/g. Results from 12 different source materials show that the formation of increased porosity in pyrolytic carbons is strongly associated with the presence of inorganic elements in the precursors including: magnesium, potassium and sulfur. It was found that pyrolysis of macro-algae can produce especially high specific surface area carbons (mean: 1500 m(2)/g), without externally applied activating agents. Using cheap readily available agricultural residues such as oilseed rape straw, pyrolytic carbons can be produced with specific surface areas of around 950 m(2)/g. Copyright © 2014 Elsevier Ltd. All rights reserved.

Biodiesel waste as source of organic carbon for municipal WWTP denitrification.

PubMed

Bodík, I; Blstáková, A; Sedlácek, S; Hutnan, M

2009-04-01

This paper presents the results of experiments to test biodiesel waste (glycerine--g-phase) as an organic carbon source for the removal of nitrate in a WWTP denitrification process. Investigation of g-phase was first centered on g-phase utilization as an external source for denitrification under laboratory conditions and consequently, after positive results from the laboratory investigation, g-phase was applied in the denitrification process in the WWTP Vrútky (35,000 PE). This WWTP had insufficient nitrogen removal via denitrification. Denitrification was insufficient due to an influent with a low BOD5/N ratio (1.7:1) entering into the activated sludge tank. Laboratory experiments and calculations showed that, to reach Ntotal concentration under 10 mg l(-1) in effluent, a biodiesel waste dose of 500 kg(COD) d(-1) was necessary. Glycerol phase (g-phase) dosing into the denitrification tank increased denitrification efficiency by 2.0 - 5.0 mg(NO)(3)(-N)l(-1) per 100 l of g-phase dose into the denitrification tank.

Fabrication and characterization of rice husk and coconut shell charcoal based bio-briquettes as alternative energy source

NASA Astrophysics Data System (ADS)

Yuliah, Y.; Kartawidjaja, M.; Suryaningsih, S.; Ulfi, K.

2017-05-01

Rice husk and coconut shell have been disposed or burned as waste. As biomass, both of materials are the potential sources of carbon which can be utilized as alternative energy sources. The energy content can be exploited more intensively when packaged in a brief and convenient. In this work, the mixtures of rice husks and coconut shells charcoal were prepared as briquettes. After going through the carbonization process, several measurements have been taken to find out the factors that determine the value of heat energy contains by each component of the charcoals. The basic ingredients briquettes prepared from rice husk and coconut shell charcoal with varying composition and addition of tapioca starch gradually as adhesive material to obtain briquettes in solid with the maximum heat energy content. After going through pressing and drying process, the briquettes with 50:50 percent of composition and the 6% addition of adhesive was found has the highest heat energy content, equal to 4966 cal/g.

What, Where, When, Who and How: Accounting for Biogenic CO2 Emissions Fluxes

NASA Astrophysics Data System (ADS)

Ohrel, S. B.

2013-12-01

The world is facing a future with a changing climate as well as increasing energy needs. Many countries, including the United States, are therefore considering an increased role of biomass in domestic energy portfolios. Accounting for emissions related to biomass production and use for energy is a complex issue: determining the extent to which biomass utilization can contribute to meeting energy needs while not contributing additional GHG emissions to the atmosphere necessitates further research. Such analysis becomes more challenging when evaluating biogenic feedstocks with long rotations (i.e., woody biomass). Detailed analysis and new accounting methods are needed in order to better assess and understand the potential implications of increased bioenergy utilization in the United States energy portfolio. In response to the EPA's 2011 Draft Accounting Framework for Biogenic CO2 Emissions from Stationary Sources, the Biogenic Carbon Emissions Panel (BCE Panel) appointed by the Science Advisory Board (2013) found that 'Carbon neutrality cannot be assumed for all biomass energy a priori. There are circumstances in which biomass is grown, harvested and combusted in a carbon neutral fashion but carbon neutrality is not an appropriate a priori assumption; it is a conclusion that should be reached only after considering a particular feedstock's production and consumption cycle. There is considerable heterogeneity in feedstock types, sources and production methods and thus net biogenic carbon emissions will vary considerably.' In that light, this study discusses the current policy discussion on biogenic feedstock use for energy in the United States. It then evaluates the question: how can we account for stationary source biogenic CO2 emissions while considering the biological cycling of carbon on the biogenic feedstock production landscape? The analysis discusses current biogenic feedstock usage in the U.S. and potential future impacts of increased biogenic feedstock production on U.S. land use, supply of non-energy commodities (e.g., timber, food crops), and related GHG emission fluxes. This paper first assesses current methods for accounting for land use sector biogenic CO2 emissions (i.e., IPCC approach). Based on the finding that no current methods exist for linking stationary source emissions with the land producing biogenic feedstocks, a unique method is needed that takes into consideration the biological cycling of carbon when accounting for biogenic emissions from energy use. The paper then describes the key technical and scientific considerations that should be taken in account, such as: the implications of baseline chosen; the important roles of temporal and spatial scales; emissions fluxes during feedstock production as well as transportation, storage and processing; the role of land use management and change, etc. It also discusses how these considerations can vary depending on feedstock type (e.g., long versus short rotation).

Altered soil microbial community at elevated CO2 leads to loss of soil carbon

PubMed Central

Carney, Karen M.; Hungate, Bruce A.; Drake, Bert G.; Megonigal, J. Patrick

2007-01-01

Increased carbon storage in ecosystems due to elevated CO2 may help stabilize atmospheric CO2 concentrations and slow global warming. Many field studies have found that elevated CO2 leads to higher carbon assimilation by plants, and others suggest that this can lead to higher carbon storage in soils, the largest and most stable terrestrial carbon pool. Here we show that 6 years of experimental CO2 doubling reduced soil carbon in a scrub-oak ecosystem despite higher plant growth, offsetting ≈52% of the additional carbon that had accumulated at elevated CO2 in aboveground and coarse root biomass. The decline in soil carbon was driven by changes in soil microbial composition and activity. Soils exposed to elevated CO2 had higher relative abundances of fungi and higher activities of a soil carbon-degrading enzyme, which led to more rapid rates of soil organic matter degradation than soils exposed to ambient CO2. The isotopic composition of microbial fatty acids confirmed that elevated CO2 increased microbial utilization of soil organic matter. These results show how elevated CO2, by altering soil microbial communities, can cause a potential carbon sink to become a carbon source. PMID:17360374

The production of cyanobacterial carbon under nitrogen-limited cultivation and its potential for nitrate removal.

PubMed

Huang, Yingying; Li, Panpan; Chen, Guiqin; Peng, Lin; Chen, Xuechu

2018-01-01

Harmful cyanobacterial blooms (CyanoHABs) represent a serious threat to aquatic ecosystems. A beneficial use for these harmful microorganisms would be a promising resolution of this urgent issue. This study applied a simple method, nitrogen limitation, to cultivate cyanobacteria aimed at producing cyanobacterial carbon for denitrification. Under nitrogen-limited conditions, the common cyanobacterium, Microcystis, efficiently used nitrate, and had a higher intracellular C/N ratio. More importantly, organic carbons easily leached from its dry powder; these leachates were biodegradable and contained a larger amount of dissolved organic carbon (DOC) and carbohydrates, but a smaller amount of dissolved total nitrogen (DTN) and proteins. When applied to an anoxic system with a sediment-water interface, a significant increase of the specific NO X - -N removal rate was observed that was 14.2 times greater than that of the control. This study first suggests that nitrogen-limited cultivation is an efficient way to induce organic and carbohydrate accumulation in cyanobacteria, as well as a high C/N ratio, and that these cyanobacteria can act as a promising carbon source for denitrification. The results indicate that application as a carbon source is not only a new way to utilize cyanobacteria, but it also contributes to nitrogen removal in aquatic ecosystems, further limiting the proliferation of CyanoHABs. Copyright © 2017. Published by Elsevier Ltd.

Environment impacts the metabolic dependencies of Ras-driven non-small cell lung cancer

PubMed Central

Davidson, Shawn M.; Papagiannakopoulos, Thales; Olenchock, Benjamin A.; Heyman, Julia E.; Keibler, Mark A.; Luengo, Alba; Bauer, Matthew R.; Jha, Abhishek K.; O’Brien, James P.; Pierce, Kerry A.; Gui, Dan Y.; Sullivan, Lucas B.; Wasylenko, Thomas M.; Subbaraj, Lakshmipriya; Chin, Christopher R.; Stephanopolous, Gregory; Mott, Bryan T.; Jacks, Tyler; Clish, Clary B.; Vander Heiden, Matthew G.

2016-01-01

SUMMARY Cultured cells convert glucose to lactate and glutamine is the major source of tricarboxylic acid (TCA) cycle carbon, but whether the same metabolic phenotype is found in tumors is less studied. We infused mice with lung cancers with isotope-labeled glucose or glutamine and compared the fate of these nutrients in tumor and normal tissue. As expected, lung tumors exhibit increased lactate production from glucose. However, glutamine utilization by both lung tumors and normal lung was minimal, with lung tumors showing increased glucose contribution to the TCA cycle relative to normal lung tissue. Deletion of enzymes involved in glucose oxidation demonstrates that glucose carbon contribution to the TCA cycle is required for tumor formation. These data suggest that understanding nutrient utilization by tumors can predict metabolic dependencies of cancers in vivo. Furthermore, these data argue that the in vivo environment is an important determinant of the metabolic phenotype of cancer cells. PMID:26853747

Elucidating carbon sources driving microbial metabolism during oil sands reclamation.

PubMed

Bradford, Lauren M; Ziolkowski, Lori A; Goad, Corey; Warren, Lesley A; Slater, Gregory F

2017-03-01

Microbial communities play key roles in remediation and reclamation of contaminated environments via biogeochemical cycling of organic and inorganic components. Understanding the trends in in situ microbial community abundance, metabolism and carbon sources is therefore a crucial component of effective site management. The focus of this study was to use radiocarbon analysis to elucidate the carbon sources driving microbial metabolism within the first pilot wetland reclamation project in the Alberta oil sands region where the observation of H 2 S had indicated the occurrence of microbial sulphate reduction. The reclamation project involved construction of a three compartment system consisting of a freshwater wetland on top of a sand cap overlying a composite tailings (CT) deposit. Radiocarbon analysis demonstrated that both dissolved and sediment associated organic carbon associated with the deepest compartments (the CT and sand cap) was primarily fossil (Δ 14 C = -769 to -955‰) while organic carbon in the overlying peat was hundreds to thousands of years old (Δ 14 C = -250 to -350‰). Radiocarbon contents of sediment associated microbial phospholipid fatty acids (PLFA) were consistent with the sediment bulk organic carbon pools (Peat: Δ 14 C PLFA  = -257‰; Sand cap Δ 14 C PLFA  = -805‰) indicating that these microbes were using sediment associated carbon. In contrast, microbial PLFA grown on biofilm units installed in wells within the deepest compartments contained much more modern carbon that the associated bulk carbon pools. This implied that the transfer of relatively more modern carbon was stimulating the microbial community at depth within the system. Correlation between cellular abundance estimates based on PLFA concentrations and the Δ 14 C PLFA indicated that the utilization of this more modern carbon was stimulating the microbial community at depth. These results highlight the importance of understanding the occurrence and potential outcomes of the introduction of relatively bioavailable carbon to mine wastes in order to predict and manage the performance of reclamation strategies. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessing the potential of amino acid δ13C patterns as a carbon source tracer in marine sediments: effects of algal growth conditions and sedimentary diagenesis

NASA Astrophysics Data System (ADS)

Larsen, T.; Bach, L. T.; Salvatteci, R.; Wang, Y. V.; Andersen, N.; Ventura, M.; McCarthy, M. D.

2015-01-01

Burial of organic carbon in marine sediments has a profound influence in marine biogeochemical cycles, and provides a sink for greenhouse gases such as CO2 and CH4. However, tracing organic carbon from primary production sources as well as its transformations in the sediment record remains challenging. Here we examine a novel but growing tool for tracing biosynthetic origin of amino acid carbon skeletons, based on natural occurring stable carbon isotope patterns in individual amino acids (δ13CAA). We focus on two important aspects for δ13CAA utility in sedimentary paleoarchives: first, the fidelity of source diagnostic of algal δ13CAA patterns across different oceanographic growth conditions; and second, the ability of δ13CAA patterns to record the degree of subsequent microbial amino acid synthesis after sedimentary burial. Using the marine diatom Thalassiosira weissflogii, we tested under controlled conditions how δ13CAA patterns respond to changing environmental conditions, including light, salinity, temperature, and pH. Our findings show that while differing oceanic growth conditions can change macromolecular cellular composition, δ13CAA isotopic patterns remain largely invariant. These results underscore that δ13CAA patterns should accurately record biosynthetic sources across widely disparate oceanographic conditions. We also explored how δ13CAA patterns change as a function of age, total nitrogen and organic carbon content after burial, in a marine sediment core from a coastal upwelling area off Peru. Based on the four most informative amino acids for distinguishing between diatom and bacterial sources (i.e. isoleucine, lysine, leucine and tyrosine), bacterial derived amino acids ranged from 10-15% in the sediment layers from the last 5000 years to 35% during the last glacial period. The larger bacterial fractions in older sediments indicate that bacterial activity and amino acid resynthesis progressed, approximately as a function of sediment age, to a substantially larger degree than suggested by changes in total organic nitrogen and carbon content. Taken together, these culturing and sediment studies suggest that δ13CAA patterns in sediments represent a novel proxy for understanding both primary production sources, as well as direct bacterial role in the ultimate preservation of sedimentary organic matter.

Engineering Graphene Films from Coal

NASA Astrophysics Data System (ADS)

Vijapur, Santosh H.

Graphene is a unique material with remarkable properties suitable for a wide array of applications. Chemical vapor deposition (CVD) is a simple technique for synthesis of large area and high quality graphene films on various metal substrates. Among the metal substrates, copper has been shown to be an excellent support for the growth of graphene films. Traditionally, hydrocarbon gases are used for the graphene synthesis via CVD. Unconventional solid carbon sources such as various polymers and food waste have also shown great potential for synthesis of graphene films. Coal is one such carbon enriched and abundantly available unconventional source. Utilization of coal as a carbon source to synthesize large area, transparent, and high quality few-layer graphene films via CVD has been demonstrated in the present work. Hydrocarbon gases are released as products of coal pyrolysis at temperatures ≥400 °C. This study hypothesized that, these hydrocarbon gases act as precursors for the synthesis of graphene films on the copper substrate. Hence, atmospheric pressure CVD and low temperature of 400 °C were utilized initially for the production of graphene films. These conditions were suitable for the formation of amorphous carbon (a-C) films but not crystalline graphene films that were the objective of this work. The synthesized a-C films on the copper substrate were shown to be uniform and transparent with large surface area. The thickness and surface roughness of the a-C films were determined to have typical values of 5 nm and 0.55 nm, respectively. The a-C film has >95 % optical transmittance and sheet resistivity of 0.6 MO sq-1. These values are comparable to other carbon thin films synthesized at higher temperatures. Further, the a-C films were transferred onto any type of substrate such as silicon wafer and titanium foil, and can be utilized for diverse applications. However, crystalline graphene films were not produced by implementing atmospheric pressure CVD and low temperature operation. Annealing of copper support was required to remove the oxide layer present on its surface and low pressure operation was demonstrated to be suitable for crystalline graphene film formation. The CVD system and the synthesis procedure were modified to address these issues. This was done by increasing the synthesis temperature, incorporating a vacuum pump for low pressure operation, and implementing two step procedure of annealing the copper substrate followed by subsequent coal pyrolysis for the synthesis of crystalline graphene films. The synthesized few layer graphene films were uniform and continuous with thickness in the range of 3-7 nm. The optical transmittance and electrical conductivity measurements demonstrated that the graphene films have >95 % transparency and sheet resistivity of 5.0 kO sq-1, respectively. An investigation of growth mechanism of coal derived graphene films synthesized via CVD was conducted utilizing spectroscopy, microscopy, and chromatography techniques. Gas collection was performed at the graphene synthesis conditions utilizing the CVD reactor without vacuum in operation. Various gases released as products of coal pyrolysis in the CVD reactor were collected and analyzed using gas chromatography. The analysis showed the presence of methane, ethane, ethene, propane, propene, carbon monoxide, and carbon dioxide as coal pyrolysis products. The hydrocarbon gases act as precursors for graphene growth. Raman spectroscopy, selected area electron diffraction (SAED), and X-ray photoelectron spectroscopy (XPS) confirmed the formation of crystalline graphene films at 1055 °C and 18-30 min synthesis. The growth mechanism involves copper catalyzed reaction to produce amorphous carbon film within the first few minutes of synthesis. Raman spectroscopy and SAED validated that lower synthesis times (6-12 min) produced hybrid amorphous carbon films. This is followed by hydrogen catalyzed graphitization of the underlying carbon film to form graphene domains. Optical microscopy and Raman spectra demonstrated the formation of these oval shaped graphene domains as synthesis time was increased (18-30 min). The graphene films are formed by growth and merging of these graphene domains on the copper substrate. The growth mechanism of coal derived crystalline graphene films is presented in the current work.

Analysis of factors affecting the accuracy, reproducibility, and interpretation of microbial community carbon source utilization patterns

USGS Publications Warehouse

Haack, S.K.; Garchow, H.; Klug, M.J.; Forney, L.J.

1995-01-01

We determined factors that affect responses of bacterial isolates and model bacterial communities to the 95 carbon substrates in Biolog microliter plates. For isolates and communities of three to six bacterial strains, substrate oxidation rates were typically nonlinear and were delayed by dilution of the inoculum. When inoculum density was controlled, patterns of positive and negative responses exhibited by microbial communities to each of the carbon sources were reproducible. Rates and extents of substrate oxidation by the communities were also reproducible but were not simply the sum of those exhibited by community members when tested separately. Replicates of the same model community clustered when analyzed by principal- components analysis (PCA), and model communities with different compositions were clearly separated un the first PCA axis, which accounted for >60% of the dataset variation. PCA discrimination among different model communities depended on the extent to which specific substrates were oxidized. However, the substrates interpreted by PCA to be most significant in distinguishing the communities changed with reading time, reflecting the nonlinearity of substrate oxidation rates. Although whole-community substrate utilization profiles were reproducible signatures for a given community, the extent of oxidation of specific substrates and the numbers or activities of microorganisms using those substrates in a given community were not correlated. Replicate soil samples varied significantly in the rate and extent of oxidation of seven tested substrates, suggesting microscale heterogeneity in composition of the soil microbial community.

Precipitation of alacranite (As8S9) by a novel As(V)-respiring anaerobe strain MPA-C3.

PubMed

Mumford, Adam C; Yee, Nathan; Young, Lily Y

2013-10-01

Strain MPA-C3 was isolated by incubating arsenic-bearing sediments under anaerobic, mesophilic conditions in minimal media with acetate as the sole source of energy and carbon, and As(V) as the sole electron acceptor. Following growth and the respiratory reduction of As(V) to As(III), a yellow precipitate formed in active cultures, while no precipitate was observed in autoclaved controls, or in uninoculated media supplemented with As(III). The precipitate was identified by X-ray diffraction as alacranite, As8 S9 , a mineral previously only identified in hydrothermal environments. Sequencing of the 16S rRNA gene indicated that strain MPA-C3 is a member of the Deferribacteres family, with relatively low (90%) identity to Denitrovibrio acetiphilus DSM 12809. The arsenate respiratory reductase gene, arrA, was sequenced, showing high homology to the arrA gene of Desulfitobacterium halfniense. In addition to As(V), strain MPA-C3 utilizes NO3(-), Se(VI), Se(IV), fumarate and Fe(III) as electron acceptors, and acetate, pyruvate, fructose and benzoate as sources of carbon and energy. Analysis of a draft genome sequence revealed multiple pathways for respiration and carbon utilization. The results of this work demonstrate that alacranite, a mineral previously thought to be formed only chemically under hydrothermal conditions, is precipitated under mesophilic conditions by the metabolically versatile strain MPA-C3. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

Production of targeted poly(3-hydroxyalkanoates) copolymers by glycogen accumulating organisms using acetate as sole carbon source.

PubMed

Dai, Yu; Yuan, Zhiguo; Jack, Kevin; Keller, Jurg

2007-05-01

One of the main limitations in bacterial polyhydroxyalkanoate (PHA) production with mixed cultures is the fact that primarily polyhydroxybutyrate (PHB) homopolymers are generated from acetate as the main carbon source, which is brittle and quite fragile. The incorporation of different 3-hydroxyalkanoate (HA) components into the polymers requires the addition of additional carbon sources, leading to extra costs and complexity. In this study, the production of poly(3-hydroxybutyrate (3HB)-co-3-hydroxyvalerate (3HV)-co-3-hydroxy-2-methylvalerate (3HMV)), with 7-35C-mol% of 3HV fractions from acetate as the only carbon source was achieved with the use of glycogen accumulating organisms (GAOs). An enriched GAO culture was obtained in a lab-scale reactor operated under alternating anaerobic and aerobic conditions with acetate fed at the beginning of the anaerobic period. The production of PHAs utilizing the enriched GAO culture was investigated under both aerobic and anaerobic conditions. A polymer content of 14-41% of dry cell weight was obtained. The PHA product accumulated by GAOs under anaerobic conditions contained a relatively constant proportion of non-3HB monomers (30+/-5C-mol%), irrespective of the amount of acetate assimilated. In contrast, under aerobic conditions, GAOs only produced 3HB monomers from acetate causing a gradually decreasing 3HV fraction during this aerobic feeding period. The PHAs were characterized by gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The data demonstrated that the copolymers possessed similar characteristics to those of commercially available poly(3HB-co-3HV) (PHBV) products. The PHAs produced under solely anaerobic conditions possessed lower melting points and crystallinity, higher molecular weights, and narrower molecular-weight distributions, compared to the aerobically produced polymers. This paper hence demonstrates the significant potential of GAOs to produce high quality polymers from a simple and cheap carbon source, contributing considerably to the growing research body on bacterial PHA production by mixed cultures.

Investigating the strategies for microbial production of trehalose from lignocellulosic sugars.

PubMed

Wu, Yifei; Wang, Jian; Shen, Xiaolin; Wang, Jia; Chen, Zhenya; Sun, Xinxiao; Yuan, Qipeng; Yan, Yajun

2018-03-01

Trehalose, a multi-functional and value-added disaccharide, can be efficiently biosynthesized from glucose by using a synergetic carbon utilization mechanism (SynCar) which coupled phosphoenolpyruvate (PEP) generation from the second carbon source with PEP-dependent phosphotransferase system (PTS) to promote non-catabolic use of glucose. Considering glucose and xylose present in large amounts in lignocellulosic sugars, we explored new strategies for conversion of both sugars into trehalose. Herein, we first attempted trehalose production from xylose directly, based on which, synergetic utilization of glucose, and xylose prompted by SynCar was implemented in engineered Escherichia coli. As the results, the final titer of trehalose reached 5.55 g/L in shake flask experiments. The conversion ratio or utilization efficiency of glucose or xylose to trehalose was around fourfold higher than that of the original strain (YW-3). This work not only demonstrated the possibility of directly converting xylose (C5 sugar) into trehalose (C12 disaccharide), but also suggested a promising strategy for trehalose production from lignocellulosic sugars for the first time. © 2017 Wiley Periodicals, Inc.

Tracing carbon flow through coral reef food webs using a compound-specific stable isotope approach.

PubMed

McMahon, Kelton W; Thorrold, Simon R; Houghton, Leah A; Berumen, Michael L

2016-03-01

Coral reefs support spectacularly productive and diverse communities in tropical and sub-tropical waters throughout the world's oceans. Debate continues, however, on the degree to which reef biomass is supported by new water column production, benthic primary production, and recycled detrital carbon (C). We coupled compound-specific stable C isotope ratio (δ(13)C) analyses with Bayesian mixing models to quantify C flow from primary producers to coral reef fishes across multiple feeding guilds and trophic positions in the Red Sea. Analyses of reef fishes with putative diets composed primarily of zooplankton (Amblyglyphidodon indicus), benthic macroalgae (Stegastes nigricans), reef-associated detritus (Ctenochaetus striatus), and coral tissue (Chaetodon trifascialis) confirmed that δ(13)C values of essential amino acids from all baseline C sources were both isotopically diagnostic and accurately recorded in consumer tissues. While all four source end-members contributed to the production of coral reef fishes in our study, a single-source end-member often dominated dietary C assimilation of a given species, even for highly mobile, generalist top predators. Microbially reworked detritus was an important secondary C source for most species. Seascape configuration played an important role in structuring resource utilization patterns. For instance, Lutjanus ehrenbergii showed a significant shift from a benthic macroalgal food web on shelf reefs (71 ± 13 % of dietary C) to a phytoplankton-based food web (72 ± 11 %) on oceanic reefs. Our work provides insights into the roles that diverse C sources play in the structure and function of coral reef ecosystems and illustrates a powerful fingerprinting method to develop and test nutritional frameworks for understanding resource utilization.

The Carolina Center of Cancer Nanotechnology Excellence: Past Accomplishments and Future Perspectives

PubMed Central

JULIANO, R.L.; SUNNARBORG, S.; DESIMONE, J.; HAROON, Z.

2013-01-01

SUMMARY The Carolina Center of Cancer Nanotechnology Excellence (C-CCNE) is funded by the National Cancer Institute and is based at the University of North Carolina. The C-CCNE features interactions among physical and biological scientists in a series of projects and cores that work together to quickly harness innovations in nanotechnology for the early diagnosis and treatment of cancer. Two key focus areas of the C-CCNE are, first the selective delivery of drugs and imaging agents utilizing advanced nanoparticle technology, and second novel approaches to imaging and radiotherapy utilizing carbon nanotube based X-ray sources. PMID:21182415

Correlation of Lactobacillus rhamnosus Genotypes and Carbohydrate Utilization Signatures Determined by Phenotype Profiling

PubMed Central

Lambert, Jolanda; van Limpt, Kees; Wels, Michiel; Smokvina, Tamara; Knol, Jan; Kleerebezem, Michiel

2015-01-01

Lactobacillus rhamnosus is a bacterial species commonly colonizing the gastrointestinal (GI) tract of humans and also frequently used in food products. While some strains have been studied extensively, physiological variability among isolates of the species found in healthy humans or their diet is largely unexplored. The aim of this study was to characterize the diversity of carbohydrate utilization capabilities of human isolates and food-derived strains of L. rhamnosus in relation to their niche of isolation and genotype. We investigated the genotypic and phenotypic diversity of 25 out of 65 L. rhamnosus strains from various niches, mainly human feces and fermented dairy products. Genetic fingerprinting of the strains by amplified fragment length polymorphism (AFLP) identified 11 distinct subgroups at 70% similarity and suggested niche enrichment within particular genetic clades. High-resolution carbohydrate utilization profiling (OmniLog) identified 14 carbon sources that could be used by all of the strains tested for growth, while the utilization of 58 carbon sources differed significantly between strains, enabling the stratification of L. rhamnosus strains into three metabolic clusters that partially correlate with the genotypic clades but appear uncorrelated with the strain's origin of isolation. Draft genome sequences of 8 strains were generated and employed in a gene-trait matching (GTM) analysis together with the publicly available genomes of L. rhamnosus GG (ATCC 53103) and HN001 for several carbohydrates that were distinct for the different metabolic clusters: l-rhamnose, cellobiose, l-sorbose, and α-methyl-d-glucoside. From the analysis, candidate genes were identified that correlate with l-sorbose and α-methyl-d-glucoside utilization, and the proposed function of these genes could be confirmed by heterologous expression in a strain lacking the genes. This study expands our insight into the phenotypic and genotypic diversity of the species L. rhamnosus and explores the relationships between specific carbohydrate utilization capacities and genotype and/or niche adaptation of this species. PMID:26048937

Strontium isotope record of seasonal scale variations in sediment sources and accumulation in low-energy, subtidal areas of the lower Hudson River estuary

USGS Publications Warehouse

Smith, J.P.; Bullen, T.D.; Brabander, D.J.; Olsen, C.R.

2009-01-01

Strontium isotope (87Sr/86Sr) profiles in sediment cores collected from two subtidal harbor slips in the lower Hudson River estuary in October 2001 exhibit regular patterns of variability with depth. Using additional evidence from sediment Ca/Sr ratios, 137Cs activity and Al, carbonate (CaCO3), and organic carbon (OCsed) concentration profiles, it can be shown that the observed variability reflects differences in the relative input and trapping of fine-grained sediment from seaward sources vs. landward sources linked to seasonal-scale changes in freshwater flow. During high flow conditions, the geochemical data indicate that most of the fine-grained sediments trapped in the estuary are newly eroded basin materials. During lower (base) flow conditions, a higher fraction of mature materials from seaward sources with higher carbonate content is trapped in the lower estuary. Results show that high-resolution, multi-geochemical tracer approaches utilizing strontium isotope ratios (87Sr/86Sr) can distinguish sediment sources and constrain seasonal scale variations in sediment trapping and accumulation in dynamic estuarine environments. Low-energy, subtidal areas such as those in this study are important sinks for metastable, short-to-medium time scale sediment accumulation. These results also show that these same areas can serve as natural recorders of physical, chemical, and biological processes that affect particle and particle-associated material dynamics over seasonal-to-yearly time scales. ?? 2009.

Biomass and carbon stock potential of Gliricidia Sepium as an alternative energy at Timor Tengah Utara Regency, East Nusa Tenggara Province, Indonesia

NASA Astrophysics Data System (ADS)

Prima, F. H.; Hariyadi; Hartono, A.

2018-03-01

The utilization of biomass from plants is one efforts for the fulfillment an availability of alternative energy in indonesia. Gliricidia sepium is a tolerant species that can grow in dry land. However its utilization as renewable energy source is non-optimized. This study aims to analyze the potential carbon stocks and biomass from Gliricidia sepium as a raw material for alternative energy in East Nusa Tenggara. This study was conducted in November 2015 and located in Humusu Sainiup, Timor Tengah Utara Regency, East Nusa Tenggara Province. The method used in collecting data was applied in three different land-use, namely monoculture Gliricidia sepium, polyculture between Gliricidia sepium and Leucaena leucocephala, and polyculture between Gliricidia sepium and Zea mays. We used the allometric equation from Ketterings namely B = 0.11ρD2+0,62 and C = 0.5 x B. The results showed that the different land-use will give different value of carbon stocks which is in this study the biggest value of carbon stocks was found in monoculture of Gliricidia sp (35.35 tC ha-1) compared with Gliricidia sp + Leucaena sp (18.83 tC ha-1), and Gliricidia sp + Zea mays (13.79 tC ha-1). The value of biomass and carbon stocks was influenced by wood density, trees density, and diameter at breast height (dbh).

High-level production of recombinant trypsin in transgenic rice cell culture through utilization of an alternative carbon source and recycling system.

PubMed

Kim, Nan-Sun; Yu, Hwa-Young; Chung, Nguyen-Duc; Kwon, Tae-Ho; Yang, Moon-Sik

2014-09-01

Productivity of recombinant bovine trypsin using a rice amylase 3D promoter has been studied in transgenic rice suspension culture. Alternative carbon sources were added to rice cell suspension cultures in order to improve the production of recombinant bovine trypsin. It was demonstrated that addition of alternative carbon sources such as succinic acid, fumaric acid and malic acid in the culture medium could increase the productivity of recombinant bovine trypsin 3.8-4.3-fold compared to those in the control medium without carbon sources. The highest accumulated trypsin reached 68.2 mg/L on day 5 in the culture medium with 40 mM fumaric acid. The feasibility of repeated use of the cells for recombinant trypsin production was tested in transgenic rice cell suspension culture with the culture medium containing the combination of variable sucrose concentration and 40 mM fumaric acid. Among the used combinations, the combination of 1% sucrose and 40 mM fumaric acid resulted in a yield of up to 53 mg/L five days after incubation. It also increased 31% (W/W) of dry cell weight and improved 43% of cell viability compared to that in control medium without sucrose. Based on these data, recycling of the trypsin production process with repeated 1% sucrose and 40 mM fumaric acid supplying-harvesting cycles was developed in flask scale culture. Recombinant bovine trypsin could be stably produced with a yield of up to 53-39 mg/L per cycle during five recycling cycles. Copyright © 2014 Elsevier Inc. All rights reserved.

Synergistic Microbial Consortium for Bioenergy Generation from Complex Natural Energy Sources

PubMed Central

Yam, Joey Kuok Hoong; Chua, Song-Lin; Zhang, Qichun; Cao, Bin; Chye, Joachim Loo Say

2014-01-01

Microbial species have evolved diverse mechanisms for utilization of complex carbon sources. Proper combination of targeted species can affect bioenergy production from natural waste products. Here, we established a stable microbial consortium with Escherichia coli and Shewanella oneidensis in microbial fuel cells (MFCs) to produce bioenergy from an abundant natural energy source, in the form of the sarcocarp harvested from coconuts. This component is mostly discarded as waste. However, through its usage as a feedstock for MFCs to produce useful energy in this study, the sarcocarp can be utilized meaningfully. The monospecies S. oneidensis system was able to generate bioenergy in a short experimental time frame while the monospecies E. coli system generated significantly less bioenergy. A combination of E. coli and S. oneidensis in the ratio of 1 : 9 (v : v) significantly enhanced the experimental time frame and magnitude of bioenergy generation. The synergistic effect is suggested to arise from E. coli and S. oneidensis utilizing different nutrients as electron donors and effect of flavins secreted by S. oneidensis. Confocal images confirmed the presence of biofilms and point towards their importance in generating bioenergy in MFCs. PMID:25097866

Biofuel Production Based on Carbohydrates from Both Brown and Red Macroalgae: Recent Developments in Key Biotechnologies

PubMed Central

Kawai, Shigeyuki; Murata, Kousaku

2016-01-01

Marine macroalgae (green, red and brown macroalgae) have attracted attention as an alternative source of renewable biomass for producing both fuels and chemicals due to their high content of suitable carbohydrates and to their advantages over terrestrial biomass. However, except for green macroalgae, which contain relatively easily-fermentable glucans as their major carbohydrates, practical utilization of red and brown macroalgae has been regarded as difficult due to the major carbohydrates (alginate and mannitol of brown macroalgae and 3,6-anhydro-l-galactose of red macroalgae) not being easily fermentable. Recently, several key biotechnologies using microbes have been developed enabling utilization of these brown and red macroalgal carbohydrates as carbon sources for the production of fuels (ethanol). In this review, we focus on these recent developments with emphasis on microbiological biotechnologies. PMID:26861307

Quality of poultry litter-derived granular activated carbon.

PubMed

Qiu, Guannan; Guo, Mingxin

2010-01-01

Utilization of poultry litter as a source material for generating activated carbon is a value-added and environmentally beneficial approach to recycling organic waste. In this study, the overall quality of poultry litter-derived granular activated carbon was systematically evaluated based on its various physical and chemical properties. Granular activated carbon generated from pelletized poultry litter following a typical steam-activation procedure possessed numerous micropores in the matrix. The product exhibited a mean particle diameter of 2.59 mm, an apparent density of 0.45 g cm(-3), a ball-pan hardness of 91.0, an iodine number of 454 mg g(-1), and a BET surface area of 403 m(2) g(-1). It contained high ash, nitrogen, phosphorus contents and the trace elements Cu, Zn, and As. Most of the nutrients and toxic elements were solidified and solution-unextractable. In general, poultry litter-based activated carbon demonstrated overall quality comparable to that of low-grade commercial activated carbon derived from coconut shell and bituminous coal. It is promising to use poultry litter as a feedstock to manufacture activated carbon for wastewater treatment.

Interkingdom Cross-Feeding of Ammonium from Marine Methylamine-Degrading Bacteria to the Diatom Phaeodactylum tricornutum.

PubMed

Suleiman, Marcel; Zecher, Karsten; Yücel, Onur; Jagmann, Nina; Philipp, Bodo

2016-12-15

Methylamines occur ubiquitously in the oceans and can serve as carbon, nitrogen, and energy sources for heterotrophic bacteria from different phylogenetic groups within the marine bacterioplankton. Diatoms, which constitute a large part of the marine phytoplankton, are believed to be incapable of using methylamines as a nitrogen source. As diatoms are typically associated with heterotrophic bacteria, the hypothesis came up that methylotrophic bacteria may provide ammonium to diatoms by degradation of methylamines. This hypothesis was investigated with the diatom Phaeodactylum tricornutum and monomethylamine (MMA) as the substrate. Bacteria supporting photoautotrophic growth of P. tricornutum with MMA as the sole nitrogen source could readily be isolated from seawater. Two strains, Donghicola sp. strain KarMa, which harbored genes for both monomethylamine dehydrogenase and the N methylglutamate pathway, and Methylophaga sp. strain M1, which catalyzed MMA oxidation by MMA dehydrogenase, were selected for further characterization. While strain M1 grew with MMA as the sole substrate, strain KarMa could utilize MMA as a nitrogen source only when, e.g., glucose was provided as a carbon source. With both strains, release of ammonium was detected during MMA utilization. In coculture with P. tricornutum, strain KarMa supported photoautotrophic growth with 2 mM MMA to the same extent as with the equimolar amount of NH 4 Cl. In coculture with strain M1, photoautotrophic growth of P. tricornutum was also supported, but to a much lower degree than by strain KarMa. This proof-of-principle study with a synthetic microbial community suggests that interkingdom cross-feeding of ammonium from methylamine-degrading bacteria is a contribution to phytoplankton growth which has been overlooked so far. Interactions between diatoms and heterotrophic bacteria are important for marine carbon cycling. In this study, a novel interaction is described. Bacteria able to degrade monomethylamine, which is a ubiquitous organic nitrogen compound in marine environments, can provide ammonium to diatoms. This interkingdom metabolite transfer enables growth under photoautotrophic conditions in coculture, which would not be possible in the respective monocultures. This proof-of-principle study calls attention to a so far overlooked contribution to phytoplankton growth. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Interkingdom Cross-Feeding of Ammonium from Marine Methylamine-Degrading Bacteria to the Diatom Phaeodactylum tricornutum

PubMed Central

Suleiman, Marcel; Zecher, Karsten; Yücel, Onur; Jagmann, Nina

2016-01-01

ABSTRACT Methylamines occur ubiquitously in the oceans and can serve as carbon, nitrogen, and energy sources for heterotrophic bacteria from different phylogenetic groups within the marine bacterioplankton. Diatoms, which constitute a large part of the marine phytoplankton, are believed to be incapable of using methylamines as a nitrogen source. As diatoms are typically associated with heterotrophic bacteria, the hypothesis came up that methylotrophic bacteria may provide ammonium to diatoms by degradation of methylamines. This hypothesis was investigated with the diatom Phaeodactylum tricornutum and monomethylamine (MMA) as the substrate. Bacteria supporting photoautotrophic growth of P. tricornutum with MMA as the sole nitrogen source could readily be isolated from seawater. Two strains, Donghicola sp. strain KarMa, which harbored genes for both monomethylamine dehydrogenase and the N methylglutamate pathway, and Methylophaga sp. strain M1, which catalyzed MMA oxidation by MMA dehydrogenase, were selected for further characterization. While strain M1 grew with MMA as the sole substrate, strain KarMa could utilize MMA as a nitrogen source only when, e.g., glucose was provided as a carbon source. With both strains, release of ammonium was detected during MMA utilization. In coculture with P. tricornutum, strain KarMa supported photoautotrophic growth with 2 mM MMA to the same extent as with the equimolar amount of NH4Cl. In coculture with strain M1, photoautotrophic growth of P. tricornutum was also supported, but to a much lower degree than by strain KarMa. This proof-of-principle study with a synthetic microbial community suggests that interkingdom cross-feeding of ammonium from methylamine-degrading bacteria is a contribution to phytoplankton growth which has been overlooked so far. IMPORTANCE Interactions between diatoms and heterotrophic bacteria are important for marine carbon cycling. In this study, a novel interaction is described. Bacteria able to degrade monomethylamine, which is a ubiquitous organic nitrogen compound in marine environments, can provide ammonium to diatoms. This interkingdom metabolite transfer enables growth under photoautotrophic conditions in coculture, which would not be possible in the respective monocultures. This proof-of-principle study calls attention to a so far overlooked contribution to phytoplankton growth. PMID:27694241

Small-scale spatial variability of soil microbial community composition and functional diversity in a mixed forest

NASA Astrophysics Data System (ADS)

Wang, Qiufeng; Tian, Jing; Yu, Guirui

2014-05-01

Patterns in the spatial distribution of organisms provide important information about mechanisms that regulate the diversity and complexity of soil ecosystems. Therefore, information on spatial distribution of microbial community composition and functional diversity is urgently necessary. The spatial variability on a 26×36 m plot and vertical distribution (0-10 cm and 10-20 cm) of soil microbial community composition and functional diversity were studied in a natural broad-leaved Korean pine (Pinus koraiensis) mixed forest soil in Changbai Mountain. The phospholipid fatty acid (PLFA) pattern was used to characterize the soil microbial community composition and was compared with the community substrate utilization pattern using Biolog. Bacterial biomass dominated and showed higher variability than fungal biomass at all scales examined. The microbial biomass decreased with soil depths increased and showed less variability in lower 10-20 cm soil layer. The Shannon-Weaver index value for microbial functional diversity showed higher variability in upper 0-10 cm than lower 10-20 cm soil layer. Carbohydrates, carboxylic acids, polymers and amino acids are the main carbon sources possessing higher utilization efficiency or utilization intensity. At the same time, the four carbon source types contributed to the differentiation of soil microbial communities. This study suggests the higher diversity and complexity for this mix forest ecosystem. To determine the driving factors that affect this spatial variability of microorganism is the next step for our study.

Polyhydroxyalkanoate production from sucrose by Cupriavidus necator strains harboring csc genes from Escherichia coli W.

PubMed

Arikawa, Hisashi; Matsumoto, Keiji; Fujiki, Tetsuya

2017-10-01

Cupriavidus necator H16 is the most promising bacterium for industrial production of polyhydroxyalkanoates (PHAs) because of their remarkable ability to accumulate them in the cells. With genetic modifications, this bacterium can produce poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx), which has better physical properties, as well as poly(3-hydroxybutyrate) (PHB) using plant oils and sugars as a carbon source. Considering production cost, sucrose is a very attractive raw material because it is inexpensive; however, this bacterium cannot assimilate sucrose. Here, we used the sucrose utilization (csc) genes of Escherichia coli W to generate C. necator strains that can assimilate sucrose. Especially, glucose-utilizing recombinant C. necator strains harboring the sucrose hydrolase gene (cscA) and sucrose permease gene (cscB) of E. coli W grew well on sucrose as a sole carbon source and accumulated PHB. In addition, strains introduced with a crotonyl-CoA reductase gene (ccr), ethylmalonyl-CoA decarboxylase gene (emd), and some other genetic modifications besides the csc genes and the glucose-utilizing mutations produced PHBHHx with a 3-hydroxyhexanoate (3HHx) content of maximum approximately 27 mol% from sucrose. Furthermore, when one of the PHBHHx-producing strains was cultured with sucrose solution in a fed-batch fermentation, PHBHHx with a 3HHx content of approximately 4 mol% was produced and reached 113 g/L for 65 h, which is approximately 1.5-fold higher than that produced using glucose solution.

Novel substrate (algal protein) for cultivation of Rhodospirillum rubrum.

PubMed

Vatsala, T M; Rekha, R; Srividhya, R

2011-10-01

Rhodospirillum rubrum was grown under light anaerobic conditions with phycocyanin (C-pc) extracted from Spirulina platensis as the sole source of carbon and nitrogen. When grown under these conditions cellular components like lipids, carbohydrates, protein, carotenoids, bacteriochlorophyll were similar to the one grown with malic acid and ammonium chloride. Growth of R. rubrum increased with increase in concentration of C-pc (200 to 1000 mg/l). R. rubrum also utilized C-pc under dark anaerobic condition. With both malic acid and C-pc as carbon sources C-pc was consumed only after exhaustion of malic acid under light anaerobic condition. No aberration of cell morphology was seen under scanning electron microscope (SEM). R. rubrum utilized both phycocyanobilin and phycoprotein individually as well as in combination. When grown with 1000 mg/l of phycoprotein 450 mg/l of biomass was obtained, and with combination of phycocyanobilin (75 mg/l) and phycoprotein (925 mg/l) 610 mg/l of biomass was obtained. Phycocyanobilin alone did not inhibit the growth of R. rubrum. Utilization of C-pc with protease like activity was observed in plate assay. Protease like activity was also observed as zones around the colonies in plates containing sterilized casein, gelatin and filter sterilized bovine serum albumin. No amino acids were detected in the supernatant when analyzed with ninhydrin. Extracellular protease like activity was highest when C-pc was used as substrate (2.8 U/ml). Intracellular protease like activity was not detected in cell free extracts.

Succinic acid production from sucrose by Actinobacillus succinogenes NJ113.

PubMed

Jiang, Min; Dai, Wenyu; Xi, Yonglan; Wu, Mingke; Kong, Xiangping; Ma, Jiangfeng; Zhang, Min; Chen, Kequan; Wei, Ping

2014-02-01

In this study, sucrose, a reproducible disaccharide extracted from plants, was used as the carbon source for the production of succinic acid by Actinobacillus succinogenes NJ113. During serum bottle fermentation, the succinic acid concentration reached 57.1g/L with a yield of 71.5%. Further analysis of the sucrose utilization pathways revealed that sucrose was transported and utilized via a sucrose phosphotransferase system, sucrose-6-phosphate hydrolase, and a fructose PTS. Compared to glucose utilization in single pathway, more pathways of A. succinogenes NJ113 are dependent on sucrose utilization. By changing the control strategy in a fed-batch culture to alleviate sucrose inhibition, 60.5g/L of succinic acid was accumulated with a yield of 82.9%, and the productivity increased by 35.2%, reaching 2.16g/L/h. Thus utilization of sucrose has considerable potential economics and environmental meaning. Copyright © 2014 Elsevier Ltd. All rights reserved.

Carbon Source-Dependent Inducible Metabolism of Veratryl Alcohol and Ferulic Acid in Pseudomonas putida CSV86

PubMed Central

Mohan, Karishma

2017-01-01

ABSTRACT Pseudomonas putida CSV86 degrades lignin-derived metabolic intermediates, viz., veratryl alcohol, ferulic acid, vanillin, and vanillic acid, as the sole sources of carbon and energy. Strain CSV86 also degraded lignin sulfonate. Cell respiration, enzyme activity, biotransformation, and high-pressure liquid chromatography (HPLC) analyses suggest that veratryl alcohol and ferulic acid are metabolized to vanillic acid by two distinct carbon source-dependent inducible pathways. Vanillic acid was further metabolized to protocatechuic acid and entered the central carbon pathway via the β-ketoadipate route after ortho ring cleavage. Genes encoding putative enzymes involved in the degradation were found to be present at fer, ver, and van loci. The transcriptional analysis suggests a carbon source-dependent cotranscription of these loci, substantiating the metabolic studies. Biochemical and quantitative real-time (qRT)-PCR studies revealed the presence of two distinct O-demethylases, viz., VerAB and VanAB, involved in the oxidative demethylation of veratric acid and vanillic acid, respectively. This report describes the various steps involved in metabolizing lignin-derived aromatic compounds at the biochemical level and identifies the genes involved in degrading veratric acid and the arrangement of phenylpropanoid metabolic genes as three distinct inducible transcription units/operons. This study provides insight into the bacterial degradation of lignin-derived aromatics and the potential of P. putida CSV86 as a suitable candidate for producing valuable products. IMPORTANCE Pseudomonas putida CSV86 metabolizes lignin and its metabolic intermediates as a carbon source. Strain CSV86 displays a unique property of preferential utilization of aromatics, including for phenylpropanoids over glucose. This report unravels veratryl alcohol metabolism and genes encoding veratric acid O-demethylase, hitherto unknown in pseudomonads, thereby providing new insight into the metabolic pathway and gene pool for lignin degradation in bacteria. The biochemical and genetic characterization of phenylpropanoid metabolism makes it a prospective system for its application in producing valuable products, such as vanillin and vanillic acid, from lignocellulose. This study supports the immense potential of P. putida CSV86 as a suitable candidate for bioremediation and biorefinery. PMID:28188206

Development of a Carbon Sequestration Visualization Tool using Google Earth Pro

NASA Astrophysics Data System (ADS)

Keating, G. N.; Greene, M. K.

2008-12-01

The Big Sky Carbon Sequestration Partnership seeks to prepare organizations throughout the western United States for a possible carbon-constrained economy. Through the development of CO2 capture and subsurface sequestration technology, the Partnership is working to enable the region to cleanly utilize its abundant fossil energy resources. The intent of the Los Alamos National Laboratory Big Sky Visualization tool is to allow geochemists, geologists, geophysicists, project managers, and other project members to view, identify, and query the data collected from CO2 injection tests using a single data source platform, a mission to which Google Earth Pro is uniquely and ideally suited . The visualization framework enables fusion of data from disparate sources and allows investigators to fully explore spatial and temporal trends in CO2 fate and transport within a reservoir. 3-D subsurface wells are projected above ground in Google Earth as the KML anchor points for the presentation of various surface subsurface data. This solution is the most integrative and cost-effective possible for the variety of users in the Big Sky community.

Water Challenges for Geologic Carbon Capture and Sequestration

PubMed Central

Friedmann, Samuel J.; Carroll, Susan A.

2010-01-01

Carbon capture and sequestration (CCS) has been proposed as a means to dramatically reduce greenhouse gas emissions with the continued use of fossil fuels. For geologic sequestration, the carbon dioxide is captured from large point sources (e.g., power plants or other industrial sources), transported to the injection site and injected into deep geological formations for storage. This will produce new water challenges, such as the amount of water used in energy resource development and utilization and the “capture penalty” for water use. At depth, brine displacement within formations, storage reservoir pressure increases resulting from injection, and leakage are potential concerns. Potential impacts range from increasing water demand for capture to contamination of groundwater through leakage or brine displacement. Understanding these potential impacts and the conditions under which they arise informs the design and implementation of appropriate monitoring and controls, important both for assurance of environmental safety and for accounting purposes. Potential benefits also exist, such as co-production and treatment of water to both offset reservoir pressure increase and to provide local water for beneficial use. PMID:20127328

Utilization of solid catfish manure waste as carbon and nutrient source for lactic acid production.

PubMed

Shi, Suan; Li, Jing; Blersch, David M

2018-06-01

The aim of this work was to study the solid waste (manure) produced by catfish as a potential feedstock for the production of lactic acid (LA) via fermentation. The solid waste contains high levels of both carbohydrates and nutrients that are sufficient for LA bacteria. Simultaneous saccharification and co-fermentation (SSCF) was applied using enzyme and Lactobacillus pentosus, and different loadings of enzyme and solid waste were tested. Results showed LA concentrations of 35.7 g/L were obtained at 15% solids content of catfish waste. Because of the high nutrient content in the fish waste, it could also be used as supplementary substrate for nitrogen and carbon sources with other lignocellulosic materials. A combined feedstock of catfish waste and paper mill sludge was tested, increasing the final LA concentration to 43.1 g/L at 12% solids loading. The catfish waste was shown to be a potential feedstock to provide both carbon and nutrients for LA production, suggesting its use as a sole substrate or in combination with other lignocellulosic materials.

Pyrolysis Oil-Based Lipid Production as Biodiesel Feedstock by Rhodococcus opacus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Zhen; Zeng, Guangming; Kosa, Matyas

2014-11-07

Light oil from pyrolysis, which accounts for ~10 % carbon yield of the starting biomass, is a complex aqueous product that is difficult to utilize and usually discarded. This work presents the feasibility of light oil as a sole carbon source to support the growth of Rhodococcus opacus (R. opacus) that in turn accumulate triacylglycerols as biodiesel feedstock. Two types of bacteria (R. opacus PD630 and DSM 1069) were selected in this study. Research results showed that after short adaption periods both strains can grow well on this complex carbon source, as proved by the consumption of oligomers and monomersmore » in light oil. Lipid content by R. opacus PD630 and DSM 1069 was observed up to 25.8 % and 22.0 % of cell dry weight, respectively. Palmitic and stearic acids were found to be the predominant fatty acids in these bacterial cells. In addition, the light oil-based lipid production can be enhanced by reducing the pH value from 7 to 4, especially in case of DSM 1069.« less

Consolidated bioprocessing for production of polyhydroxyalkanotes from red algae Gelidium amansii.

PubMed

Sawant, Shailesh S; Salunke, Bipinchandra K; Kim, Beom Soo

2018-04-01

Noncompetitive carbon sources such as algae are unconventional and promising raw material for sustainable biofuel production. The capability of one marine bacterium, Saccharophagus degradans 2-40 to degrade red seaweed Gelidium amansii for production of polyhydroxyalkanoates (PHA) was evaluated in this study. S. degradans can readily attach to algae, degrade algal carbohydrates, and utilize that material as main carbon source. Minimal media containing 8g/L G. amansii were used for the growth of S. degradans. The PHA content obtained was 17-27% of dry cell weight by pure culture of S. degradans and co-culture of S. degradans and Bacillus cereus, a contaminant found with S. degradans cultures. The PHA type was found to be poly(3-hydroxybutyrate) by gas chromatography and Fourier transform-infrared spectroscopy. This work demonstrates PHA production through consolidated bioprocessing of insoluble, untreated red algae by bacterial pure culture and co-culture. Copyright © 2017 Elsevier B.V. All rights reserved.

Utilization of coal as a source of chemicals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demirbas, A.

Coal consists carbon-based substances can be used as a source of specialty aromatic chemicals and aliphatic chemicals. Four widespread processes allow for making chemicals from coals: gasification, liquefaction, direct conversion, and co-production of chemicals and fuels along with electricity. Coal is gasified to produce synthesis gas (syngas) with a gasifier which is then converted to paraffinic liquid fuels and chemicals by Fischer-Tropsch synthesis. Liquid product from coal gasification mainly contains benzene, toluene, xylene (BTX), phenols, alkylphenols, and cresol. Methanol is made using coal or syngas with hydrogen and carbon monoxide in a 2 to 1 ratio. Coal-derived methanol has manymore » preferable properties as it is free of sulfur and other impurities. Syngas from coal can be reformed to hydrogen. Ammonium sulfate from coal tar by pyrolysis can be converted to ammonia. The humus substances can be recovered from brown coal by alkali extraction.« less

Response of an algal consortium to diesel under varying culture conditions.

PubMed

Chavan, Anal; Mukherji, Suparna

2010-03-01

A diesel-tolerant sessile freshwater algal consortium obtained from the vicinity of Powai Lake (Mumbai, India) was cultured in the laboratory. The presence of diesel in batch cultures enhanced the maximum specific growth rate of the algal consortium. With decrease in light-dark (L:D) cycle from 20:4 to 4:20 h, the chlorophyll-a levels decreased; however, the removal of diesel was found to be maximum at L:D of 18:6 h with 37.6% degradation over and above controls. In addition to growth in the form of green clumps, white floating biomass was found surrounding the diesel droplets on the surface. This culture predominated at the least L:D ratio of 4:20 h. Studies confirmed the ability of the floating organisms to grow heterotrophically in the dark utilizing diesel as carbon source and also in the presence of light in a medium devoid of organic carbon sources.

Biodegradation of chlorpyrifos by lactic acid bacteria during kimchi fermentation.

PubMed

Cho, Kye Man; Math, Reukaradhya K; Islam, Shah Md Asraful; Lim, Woo Jin; Hong, Su Young; Kim, Jong Min; Yun, Myoung Geun; Cho, Ji Joong; Yun, Han Dae

2009-03-11

We examined the role of microorganisms in the degradation of the organophosphorus (OP) insecticide chlorpyrifos (CP) during kimchi fermentation. During the fermentation of kimchi, 30 mg L(-1) of CP was added and its stability assayed during fermentation. CP was degraded rapidly until day 3 (83.3%) and degraded completely by day 9. Four CP-degrading lactic acid bacteria (LAB) were isolated from kimchi fermentation in the presence of 200 mg L(-1) CP and were identified as Leuconostoc mesenteroides WCP907, Lactobacillus brevis WCP902, Lactobacillus plantarum WCP931, and Lactobacillus sakei WCP904. CP could be utilized by these four strains as the sole source of carbon and phosphorus. Coumaphos (CM), diazinon (DZ), parathion (PT), and methylparathion (MPT) were also degraded by WCP907, WCP902, WCP931, and WCP904 when provided as sole sources of carbon and phosphorus.

Mixotrophic and heterotrophic production of lipids and carbohydrates by a locally isolated microalga using wastewater as a growth medium.

PubMed

Nzayisenga, Jean Claude; Eriksson, Karolina; Sellstedt, Anita

2018-06-01

The biomass production and changes in biochemical composition of a locally isolated microalga (Chlorella sp.) were investigated in autotrophic, mixotrophic and heterotrophic conditions, using glucose or glycerol as carbon sources and municipal wastewater as the growth medium. Both standard methods and Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) analysis of data acquired by Fourier-transform IR (FTIR) spectrometry showed that autotrophic and mixotrophic conditions promoted carbohydrate accumulation, while heterotrophic conditions with glycerol resulted in the highest lipid content and lowest carbohydrate content. Heterotrophic conditions with glycerol as a carbon source also resulted in high oleic acid (18:1) contents and low linolenic acid (18:3) contents, and thus increasing biodiesel quality. The results also show the utility of MCR-ALS for analyzing changes in microalgal biochemical composition. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of Aromatic Compounds on Cellular Fatty Acid Composition of Rhodococcus opacus

PubMed Central

Tsitko, Irina V.; Zaitsev, Gennadi M.; Lobanok, Anatoli G.; Salkinoja-Salonen, Mirja S.

1999-01-01

In cells of Rhodococcus opacus GM-14, GM-29, and 1CP, the contents of branched (10-methyl) fatty acids increased from 3% to 15 to 34% of the total fatty acids when the cells were grown on benzene, phenol, 4-chlorophenol, chlorobenzene, or toluene as the sole source of carbon and energy, in comparison with cells grown on fructose. In addition, the content of trans-hexadecenoic acid increased from 5% to 8 to 18% with phenol or chlorophenol as the carbon source. The 10-methyl branched fatty acid content of R. opacus GM-14 cells increased in a dose-related manner following exposure to phenol or toluene when toluene was not utilized as the growth substrate. The results suggest that 10-methyl branched fatty acids may participate in the adaptation of R. opacus to lipophilic aromatic compounds. PMID:9925629

The genome and phenome of the green alga Chloroidium sp. UTEX 3007 reveal adaptive traits for desert acclimatization.

PubMed

Nelson, David R; Khraiwesh, Basel; Fu, Weiqi; Alseekh, Saleh; Jaiswal, Ashish; Chaiboonchoe, Amphun; Hazzouri, Khaled M; O'Connor, Matthew J; Butterfoss, Glenn L; Drou, Nizar; Rowe, Jillian D; Harb, Jamil; Fernie, Alisdair R; Gunsalus, Kristin C; Salehi-Ashtiani, Kourosh

2017-06-17

To investigate the phenomic and genomic traits that allow green algae to survive in deserts, we characterized a ubiquitous species, Chloroidium sp. UTEX 3007 , which we isolated from multiple locations in the United Arab Emirates (UAE). Metabolomic analyses of Chloroidium sp. UTEX 3007 indicated that the alga accumulates a broad range of carbon sources, including several desiccation tolerance-promoting sugars and unusually large stores of palmitate. Growth assays revealed capacities to grow in salinities from zero to 60 g/L and to grow heterotrophically on >40 distinct carbon sources. Assembly and annotation of genomic reads yielded a 52.5 Mbp genome with 8153 functionally annotated genes. Comparison with other sequenced green algae revealed unique protein families involved in osmotic stress tolerance and saccharide metabolism that support phenomic studies. Our results reveal the robust and flexible biology utilized by a green alga to successfully inhabit a desert coastline.

Microorganism Utilization for Synthetic Milk Production

NASA Technical Reports Server (NTRS)

Birmele, Michele; Morford, Megan; Khodadad, Christina; Spencer, Lashelle; Richards, Jeffrey; Strayer, Richard; Caro, Janicce; Hummerick, Mary; Wheeler, Ray

2014-01-01

A desired architecture for long duration spaceflight, such as aboard the International Space Station (ISS) or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of this project was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel- through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms.

A Novel Denitrifying Extreme Halophile That Grows in a Simple Mineral Salts Medium

NASA Technical Reports Server (NTRS)

Hochstein, L. I.; Oremland, R. S.; Gherna, R.; Cote, R.; Chang, Sherwood (Technical Monitor)

1995-01-01

An extremely halophilic bacterium (strain CH-1) was isolated from a saltern adjacent to San Francisco Bay. It grew in a mineral salts medium with ammonium and glucose as sole sources of nitrogen and carbon as well as energy, respectively Cells lysed at less than 10% NaCl and growth was most rapid in medium containing 20% NaCl. Cells were pieomorphic ranging from disc to ovoid-shaved and used a variety of carbohydrates as sole carbon sources. the utilization of certain carbon sources was controlled by temperature with some used at 37 degrees but not 45 C. CH-1 grew between 30 degrees and 50 C with the optimum at 45 C in the presence of 20% NaCl. CH-1 contained 2,3-di-O-isoprenyl glcerol diethers and was sensitive to aphidicofin. The major polar lipid was glucosyl-mannosyl-alucosyl diether, which is diagnostic of the Haloarcula. Thus CH-1 is an extreme halophile and a member of this genus. Among the novel characteristics of this organism was its ability to grow anaerobically in synthetic medium when nitrate was present which was only reduced to nitrous oxide. This organism should prove useful for studying denitrification and carbohydrate metabolism in the extreme halophiles; and to be a valuable resource for generic studies.

Influence of the diet components on the symbiotic microorganisms community in hindgut of Coptotermes formosanus Shiraki.

PubMed

Tanaka, Hideo; Aoyagi, Hideki; Shiina, Shunsuke; Shina, Syunsuke; Doudou, Yuri; Dodo, Yuri; Yoshimura, Tsuyoshi; Nakamura, Ryosuke; Uchiyama, Hiroo

2006-08-01

Artificial diet was developed for rearing of lower termites (workers) Coptotermes formosanus. C. formosanus was fed with either wood powder of Japanese red pine, cellulose, cellobiose, or glucose for 30 days. The effect of carbon sources in the diet on the structure and function of the symbiotic intestinal microbial community and on the physiological activity of C. formosanus was studied. Three symbiont protozoa, Pseudotrichonympha grassi, Holomastigotoides hartmanni, and Spirotrichonympha leidyi, were found in the hindgut of C. formosanus that fed on the diets containing carbon sources with high molecular weight (MW). However, when artificial diets containing carbohydrate with low MW were used, both P. grassi and H. hartmanni disappeared, and only few S. leidyi were alive. This suggested that both P. grassi and H. hartmanni play important roles in the digestion and utilization of carbohydrate with high MW. The denaturing gradient gel electrophoresis analysis of bacterial community in the hindgut of termites showed that the similarity between intestinal bacteria community in termites fed with diets containing high-MW carbon sources and those with low MW was only about 40%. It was apparent that changes in diets resulted to changes in intestinal microbial community, and this in turn affected cellulase activity in C. formosanus.

[Characterization of a thermophilic Geobacillus strain DM-2 degrading hydrocarbons].

PubMed

Liu, Qing-kun; Wang, Jun; Li, Guo-qiang; Ma, Ting; Liang, Feng-lai; Liu, Ru-lin

2008-12-01

A thermophilic Geobacillus strain DM-2 from a deep-subsurface oil reservoir was investigated on its capability of degrading crude oil under various conditions as well as its characters on degrading hydrocarbons in optimal conditions. The results showed that Geobacillus strain DM-2 was able to degrade crude oil under anoxic wide-range conditions with pH ranging from 4.0 to 10.0, high temperature in the range of 45-70 degrees C and saline concentration ranging from 0.2% to 3.0%. Furthermore, the optimal temperature and pH value for utilizing hydrocarbons by the strain were 60 degrees C and 7.0, respectively. Under such optimal conditions, the strain utilized liquid paraffine emulsified by itself as its carbon source for growth; further analysis by gas chromatography (GC) and infrared absorption spectroscopy demonstrated that it was able to degrade n-alkanes (C14-C30), branched-chain alkanes and aromatic hydrocarbons in crude oil and could also utilize long-chain n-alkanes from C16 to C36, among of which the degradation efficiency of C28 was the highest, up to 88.95%. One metabolite of the strain oxidizing alkanes is fatty acid.While utilizing C16 as carbon source for 5 d, only one fatty acid-acetic acid was detected by HPLC and MS as the product, with the amount of 0.312 g/L, which indicated that it degraded n-alkanes with pathway of inferior terminal oxidation,and then followed by a beta-oxidation pathway. Due to its characters of efficient emulsification, high-performance degradation of hydrocarbons and fatty-acid production under high temperature and anoxic condition, the strain DM-2 may be potentially applied to oil-waste treatment and microbial enhanced heavy oil recovery in extreme conditions.

Synthesis Methods of Carbon Nanotubes and Related Materials

PubMed Central

Szabó, Andrea; Perri, Caterina; Csató, Anita; Giordano, Girolamo; Vuono, Danilo; Nagy, János B.

2010-01-01

The challenge on carbon nanotubes is still the subject of many research groups. While in the first years the focus was on the new synthesis methods, new carbon sources and support materials, recently, the application possibilities are the principal arguments of the studies. The three main synthesis methods discussed in this review are the arc discharge, the laser ablation and the chemical vapour deposition (CVD) with a special regard to the latter one. In the early stage of the nanotube production the first two methods were utilized mainly for the production of SWNTs while the third one produced mainly MWNTs. The principle of CVD is the decomposition of various hydrocarbons over transition metal supported catalyst. Single-walled (SWNT), multi-walled (MWNT) and coiled carbon nanotubes are produced. In some case, interesting carbonaceous materials are formed during the synthesis process, such as bamboo-like tubes, onions, horn-like structures. In this paper, we refer to the progresses made in the field of the synthesis techniques of carbon nanotubes in the last decade.

Optimization of an Atmospheric Carbon Source for Extremophile Cyanobacteria

NASA Astrophysics Data System (ADS)

Beaubien, Courtney

This thesis examines the use of the moisture swing resin materials employed at the Center for Negative Carbon Emissions (CNCE) in order to provide carbon dioxide from ambient air to photobioreactors containing extremophile cyanobacteria cultured at the Arizona Center for Algae Technology and Innovation (AzCATI). For this purpose, a carbon dioxide feeding device was designed, built, and tested. The results indicate how much resin should be used with a given volume of algae medium: approximately 500 grams of resin can feed 1% CO2 at about three liters per minute to a ten liter medium of the Galdieria sulphuraria 5587.1 strain for one hour (equivalent to about 0.1 grams of carbon dioxide per hour per seven grams of algae). Using the resin device, the algae grew within their normal growth range: 0.096 grams of ash-free dry weight per liter over a six hour period. Future applications in which the resin-to-algae process can be utilized are discussed.

Rapid enrichment of (homo)acetogenic consortia from animal feces using a high mass-transfer gas-lift reactor fed with syngas.

PubMed

Park, Shinyoung; Yasin, Muhammad; Kim, Daehee; Park, Hee-Deung; Kang, Chang Min; Kim, Duk Jin; Chang, In Seop

2013-09-01

A gas-lift reactor having a high mass transfer coefficient (k(L)a = 80.28 h(-1)) for a relatively insoluble gas (carbon monoxide; CO) was used to enrich (homo)acetogens from animal feces. Samples of fecal matter from cow, rabbit, chicken, and goat were used as sources of inoculum for the enrichment of CO and H(2) utilizing microbial consortia. To confirm the successful enrichment, the Hungate roll tube technique was employed to count and then isolate putative CO utilizers. The results of this work showed that CO and H(2) utilizing consortia were established for each inoculum source after 8 days. The number of colony-forming units in cow, rabbit, chicken, and goat fecal samples were 3.83 × 10(9), 1.03 × 10(9), 8.3 × 10(8), and 3.25 × 10(8) cells/ml, respectively. Forty-two colonies from the animal fecal samples were screened for the ability to utilize CO/H(2). Ten of these 42 colonies were capable of utilizing CO/H(2). Five isolates from cow feces (samples 5, 6, 8, 16, and 22) were highly similar to previously unknown (homo)acetogen, while cow-7 has shown 99 % similarity with Acetobacterium sp. as acetogens. On the other hand, four isolates from chicken feces (samples 3, 8, 10, and 11) have also shown high CO/H(2) utilizing activity. Hence, it is expected that this research could be used as the basis for the rapid enrichment of (homo)acetogenic consortia from various environmental sources.

Tracking heterotrophic and autotrophic carbon cycling by magnetotactic bacteria in freshwater sediments using DNA stable isotope probing

NASA Astrophysics Data System (ADS)

Kürşat Coşkun, Ömer; Roud, Sophie; He, Kuang; Petersen, Nikolai; Gilder, Stuart; Orsi, William D.

2017-04-01

Magnetotactic bacteria (MTB) are diverse, widespread, motile prokaryotes which biomineralize nanosize magnetic minerals, either magnetite or gregite, under highly conserved genetic control and have magnetotaxis to align their position in aquatic environment according to Earth's magnetic field. They play important roles on some geobiological cycle of important minerals such as iron, sulphur, nitrogen and carbon. Yet, to date, their importance in carbon cycle and carbon source in their natural environment have not been previously studied. In this study, we focused on freshwater benthic carbon cycling of MTB and total bacteria using DNA stable isotope probing (DNA-SIP) technique coupled with quantitative PCR (qPCR). Pond sediments from Unterlippach (Germany) were amended with 13C-labelled sodium bicarbonate and 13C-labelled organic matter, and incubated in the dark over a two week time period. Applying separate qPCR assays specific for total bacteria and MTB, respectively, allowed us to estimate the contribution of MTB to total heterotrophic and autotrophic carbon cycling via DNA-SIP. After one week, there was a slight degree of autotrophic activity which increased markedly after two weeks. Comparing total DNA to the qPCR data revealed that changes in the buoyant density of DNA was due mainly to autotrophic bacterial production. DNA-SIP also identified heterotrophic utilization of 13C-labelled organic matter by MTB after 1 week. The qPCR data also allowed us to estimate uptake rates based on the incubation times for heterotrophic and autotrophic MTB. High-throughput DNA sequencing of 16S rRNA genes showed that most of the MTB involved in carbon cycling were related to the Magnetococcus genus. This study sheds light on the carbon sources for MTB in a natural environment and helps unravel their ecological role in the carbon cycle.

Utilization of heat from High Temperature Reactors (HTR) for dry reforming of methane

NASA Astrophysics Data System (ADS)

Jastrząb, Krzysztof

2018-01-01

One of the methods for utilization of waste carbon dioxide consists in reaction of methane with carbon dioxide, referred to as dry reforming of methane. It is an intensely endothermic catalytic process that takes place at the temperature above 700°C. Reaction of methane with carbon dioxide leads to formation of synthesis gas (syngas) that is a valuable chemical raw material. The energy that is necessary for the process to take place can be sourced from High Temperature Nuclear Reactors (HTR). The completed studies comprises a series of thermodynamic calculations and made it possible to establish optimum conditions for the process and demand for energy from HTR units. The dry reforming of methane needs also a catalytic agent with appropriate activity, therefore the hydrotalcite catalyser with admixture of cerium and nickel, developed at AGH University of Technology seems to be a promising solution. Thus, the researchers from the Institute for Chemical Processing of Coal (IChPW) in Zabrze have developed a methodology for production of the powdery hydrotalcite catalyser and investigated catalytic properties of the granulate obtained. The completed experiments confirmed that the new catalyser demonstrated high activity and is suitable for the process of methane dry reforming. In addition, optimum parameters of the were process (800°C, CO2:CH4 = 3:1) were established as well. Implementation of the technology in question into industrial practice, combined with utilization of HTR heat can be a promising method for management of waste carbon dioxide and may eventually lead to mitigation of the greenhouse effect.

Tracing organic matter composition and distribution and its role on arsenic release in shallow Cambodian groundwaters

NASA Astrophysics Data System (ADS)

Lawson, Michael; Polya, David A.; Boyce, Adrian J.; Bryant, Charlotte; Ballentine, Christopher J.

2016-04-01

Biogeochemical processes that utilize dissolved organic carbon are widely thought to be responsible for the liberation of arsenic from sediments to shallow groundwater in south and southeast Asia. The accumulation of this known carcinogen to hazardously high concentrations has occurred in the primary source of drinking water in large parts of densely populated countries in this region. Both surface and sedimentary sources of organic matter have been suggested to contribute dissolved organic carbon in these aquifers. However, identification of the source of organic carbon responsible for driving arsenic release remains enigmatic and even controversial. Here, we provide the most extensive interrogation to date of the isotopic signature of ground and surface waters at a known arsenic hotspot in Cambodia. We present tritium and radiocarbon data that demonstrates that recharge through ponds and/or clay windows can transport young, surface derived organic matter into groundwater to depths of 44 m under natural flow conditions. Young organic matter dominates the dissolved organic carbon pool in groundwater that is in close proximity to these surface water sources and we suggest this is likely a regional relationship. In locations distal to surface water contact, dissolved organic carbon represents a mixture of both young surface and older sedimentary derived organic matter. Ground-surface water interaction therefore strongly influences the average dissolved organic carbon age and how this is distributed spatially across the field site. Arsenic mobilization rates appear to be controlled by the age of dissolved organic matter present in these groundwaters. Arsenic concentrations in shallow groundwaters (<20 m) increase by 1 μg/l for every year increase in dissolved organic carbon age compared to only 0.25 μg/l for every year increase in dissolved organic carbon age in deeper (>20 m) groundwaters. We suggest that, while the rate of arsenic release is greatest in shallow aquifer sediments, arsenic release also occurs in deeper aquifer sediments and as such remains an important process in controlling the spatial distribution of arsenic in the groundwaters of SE Asia. Our findings suggest that any anthropogenic activities that alter the source of groundwater recharge or the timescales over which recharge takes place may also drive changes in the natural composition of dissolved organic carbon in these groundwaters. Such changes have the potential to influence both the spatial and temporal evolution of the current groundwater arsenic hazard in this region.

Cryptococcus friedmannii, a new species of yeast from the Antarctic

NASA Technical Reports Server (NTRS)

Vishniac, H. S.

1985-01-01

Cryptococcus friedmannii Vishniac sp. nov. from an Antarctic cryptoendolithic community is a psychrophilic basidioblastomycete characterized by cream-colored colonies of cells with smooth, layered walls, budding monopolarly, producing amylose and extracellular proteinase, utilizing nitrate and D-alanine (inter alia) as nitrogen sources and L-arabinose, arbutin, cellobiose, D-glucuronate, maltose, melezitose, salicin, soluble starch, trehalose, and D-xylose as carbon sources. This species differs from all other basidiomycetous yeasts in possessing the following combination of characters: amylose production (positive), assimilation of cellobiose (positive), D-galactose (negative), myo-inositol (negative), D-mannitol (negative), and sucrose (negative).

A novel promising strain of Trichoderma evansii (WF-3) for extracellular α-galactosidase production by utilizing different carbon sources under optimized culture conditions.

PubMed

Chauhan, Aishwarya; Siddiqi, Nikhat Jamal; Sharma, Bechan

2014-01-01

A potential fungal strain of Trichoderma sp. (WF-3) was isolated and selected for the production of α-galactosidase. Optimum conditions for mycelial growth and enzyme induction were determined. Basal media selected for the growth of fungal isolate containing different carbon sources like guar gum (GG), soya bean meal (SM), and wheat straw (WS) and combinations of these carbon substrates with basic sugars like galactose and sucrose were used to monitor their effects on α-galactosidase production. The results of this study indicated that galactose and sucrose enhanced the enzyme activity in guar gum (GG) and wheat straw (WS). Maximum α-galactosidase production (213.63 U mL(-1)) was obtained when the basic medium containing GG is supplemented with galactose (5 mg/mL). However, the presence of galactose and sucrose alone in the growth media shows no effect. Soya meal alone was able to support T. evansii to produce maximum enzyme activity (170.36 U mL(-1)). The incubation time, temperature, and pH for the maximum enzyme synthesis were found to be 120 h (5 days), 28°C, and 4.5-5.5, respectively. All the carbon sources tested exhibited maximum enzyme production at 10 mg/mL concentration. Among the metal ions tested, Hg was found to be the strongest inhibitor of the enzyme. Among the chelators, EDTA acted as stronger inhibitor than succinic acid.

A Novel Promising Strain of Trichoderma evansii (WF-3) for Extracellular α-Galactosidase Production by Utilizing Different Carbon Sources under Optimized Culture Conditions

PubMed Central

Chauhan, Aishwarya; Siddiqi, Nikhat Jamal

2014-01-01

A potential fungal strain of Trichoderma sp. (WF-3) was isolated and selected for the production of α-galactosidase. Optimum conditions for mycelial growth and enzyme induction were determined. Basal media selected for the growth of fungal isolate containing different carbon sources like guar gum (GG), soya bean meal (SM), and wheat straw (WS) and combinations of these carbon substrates with basic sugars like galactose and sucrose were used to monitor their effects on α-galactosidase production. The results of this study indicated that galactose and sucrose enhanced the enzyme activity in guar gum (GG) and wheat straw (WS). Maximum α-galactosidase production (213.63 UmL−1) was obtained when the basic medium containing GG is supplemented with galactose (5 mg/mL). However, the presence of galactose and sucrose alone in the growth media shows no effect. Soya meal alone was able to support T. evansii to produce maximum enzyme activity (170.36 UmL−1). The incubation time, temperature, and pH for the maximum enzyme synthesis were found to be 120 h (5 days), 28°C, and 4.5–5.5, respectively. All the carbon sources tested exhibited maximum enzyme production at 10 mg/mL concentration. Among the metal ions tested, Hg was found to be the strongest inhibitor of the enzyme. Among the chelators, EDTA acted as stronger inhibitor than succinic acid. PMID:25126562

The expression of the genes involved in leucine catabolism of Pseudomonas aeruginosa is controlled by the transcriptional regulator LiuR and by the CbrAB/Crc system.

PubMed

Díaz-Pérez, Alma Laura; Núñez, Cinthia; Meza Carmen, Victor; Campos-García, Jesús

2018-05-19

Pseudomonas aeruginosa metabolizes leucine through the leucine/isovalerate utilization pathway, whose enzymes are encoded in the liuRABCDE gene cluster (liu). In this study, we investigated the role of the LiuR protein in the liu cluster regulation. Our results indicated that liu expression is regulated at the transcriptional level by LiuR. Mobility shift assays using purified recombinant His-tagged LiuR showed that it was able to bind at the promoter region of liuR, in a dose-dependent manner. Results revealed that expression of the liu operon is subjected to carbon catabolite repression control (CCR); protein LiuD was strongly expressed in the presence of leucine, but it was repressed in the presence of glucose or succinate. Furthermore, this CCR control was dependent on LiuR as in the liuR - mutant the LiuD protein was strongly expressed in all the carbon sources tested. In agreement with this result, in the absence of the Crc protein, LiuD was expressed independently of the carbon source used, whereas in a cbrB - mutant its expression was severely impaired. The results indicated that the liu cluster is subjected to a coordinated transcriptional and translational regulation by the LiuR repressor and by the CbrAB/Crc system, respectively, in response to the available carbon source. Copyright © 2018 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Cyclic occurrence of fire and its role in carbon dynamics along an edaphic moisture gradient in longleaf pine ecosystems.

PubMed

Whelan, Andrew; Mitchell, Robert; Staudhammer, Christina; Starr, Gregory

2013-01-01

Fire regulates the structure and function of savanna ecosystems, yet we lack understanding of how cyclic fire affects savanna carbon dynamics. Furthermore, it is largely unknown how predicted changes in climate may impact the interaction between fire and carbon cycling in these ecosystems. This study utilizes a novel combination of prescribed fire, eddy covariance (EC) and statistical techniques to investigate carbon dynamics in frequently burned longleaf pine savannas along a gradient of soil moisture availability (mesic, intermediate and xeric). This research approach allowed us to investigate the complex interactions between carbon exchange and cyclic fire along the ecological amplitude of longleaf pine. Over three years of EC measurement of net ecosystem exchange (NEE) show that the mesic site was a net carbon sink (NEE = -2.48 tonnes C ha(-1)), while intermediate and xeric sites were net carbon sources (NEE = 1.57 and 1.46 tonnes C ha(-1), respectively), but when carbon losses due to fuel consumption were taken into account, all three sites were carbon sources (10.78, 7.95 and 9.69 tonnes C ha(-1) at the mesic, intermediate and xeric sites, respectively). Nonetheless, rates of NEE returned to pre-fire levels 1-2 months following fire. Consumption of leaf area by prescribed fire was associated with reduction in NEE post-fire, and the system quickly recovered its carbon uptake capacity 30-60 days post fire. While losses due to fire affected carbon balances on short time scales (instantaneous to a few months), drought conditions over the final two years of the study were a more important driver of net carbon loss on yearly to multi-year time scales. However, longer-term observations over greater environmental variability and additional fire cycles would help to more precisely examine interactions between fire and climate and make future predictions about carbon dynamics in these systems.

Cyclic Occurrence of Fire and Its Role in Carbon Dynamics along an Edaphic Moisture Gradient in Longleaf Pine Ecosystems

PubMed Central

Whelan, Andrew; Mitchell, Robert; Staudhammer, Christina; Starr, Gregory

2013-01-01

Fire regulates the structure and function of savanna ecosystems, yet we lack understanding of how cyclic fire affects savanna carbon dynamics. Furthermore, it is largely unknown how predicted changes in climate may impact the interaction between fire and carbon cycling in these ecosystems. This study utilizes a novel combination of prescribed fire, eddy covariance (EC) and statistical techniques to investigate carbon dynamics in frequently burned longleaf pine savannas along a gradient of soil moisture availability (mesic, intermediate and xeric). This research approach allowed us to investigate the complex interactions between carbon exchange and cyclic fire along the ecological amplitude of longleaf pine. Over three years of EC measurement of net ecosystem exchange (NEE) show that the mesic site was a net carbon sink (NEE = −2.48 tonnes C ha−1), while intermediate and xeric sites were net carbon sources (NEE = 1.57 and 1.46 tonnes C ha−1, respectively), but when carbon losses due to fuel consumption were taken into account, all three sites were carbon sources (10.78, 7.95 and 9.69 tonnes C ha−1 at the mesic, intermediate and xeric sites, respectively). Nonetheless, rates of NEE returned to pre-fire levels 1–2 months following fire. Consumption of leaf area by prescribed fire was associated with reduction in NEE post-fire, and the system quickly recovered its carbon uptake capacity 30–60 days post fire. While losses due to fire affected carbon balances on short time scales (instantaneous to a few months), drought conditions over the final two years of the study were a more important driver of net carbon loss on yearly to multi-year time scales. However, longer-term observations over greater environmental variability and additional fire cycles would help to more precisely examine interactions between fire and climate and make future predictions about carbon dynamics in these systems. PMID:23335986

Production of biodiesel from microalgae through biological carbon capture: a review.

PubMed

Mondal, Madhumanti; Goswami, Shrayanti; Ghosh, Ashmita; Oinam, Gunapati; Tiwari, O N; Das, Papita; Gayen, K; Mandal, M K; Halder, G N

2017-06-01

Gradual increase in concentration of carbon dioxide (CO 2 ) in the atmosphere due to the various anthropogenic interventions leading to significant alteration in the global carbon cycle has been a subject of worldwide attention and matter of potential research over the last few decades. In these alarming scenario microalgae seems to be an attractive medium for capturing the excess CO 2 present in the atmosphere generated from different sources such as power plants, automobiles, volcanic eruption, decomposition of organic matters and forest fires. This captured CO 2 through microalgae could be used as potential carbon source to produce lipids for the generation of biofuel for replacing petroleum-derived transport fuel without affecting the supply of food and crops. This comprehensive review strives to provide a systematic account of recent developments in the field of biological carbon capture through microalgae for its utilization towards the generation of biodiesel highlighting the significance of certain key parameters such as selection of efficient strain, microalgal metabolism, cultivation systems (open and closed) and biomass production along with the national and international biodiesel specifications and properties. The potential use of photobioreactors for biodiesel production under the influence of various factors viz., light intensity, pH, time, temperature, CO 2 concentration and flow rate has been discussed. The review also provides an economic overview and future outlook on biodiesel production from microalgae.

Requirement of carbon dioxide for initial growth of facultative methylotroph, Acidomonas methanolica MB58.

PubMed

Mitsui, Ryoji; Katayama, Hiroko; Tanaka, Mitsuo

2015-07-01

The facultative methylotrophic bacterium Acidomonas methanolica MB58 can utilize C1 compounds via the ribulose monophosphate pathway. A large gene cluster comprising three components related to C1 metabolism was found in the genome. From upstream, the first was an mxa cluster encoding proteins for oxidation of methanol to formaldehyde; the second was the rmp cluster encoding enzymes for formaldehyde fixation; and the third was the cbb gene cluster encoding proteins for carbon dioxide (CO2) fixation. Examination of CO2 requirements for growth of A. methanolica MB58 cells demonstrated that it did not grow on any carbon source under CO2-free conditions. Measurement of ribulose-1,5-bisphosphate carboxylase activity and RT-PCR analysis demonstrated enzymatic activity was detected in A. methanolica MB58 at growth phase, regardless of carbon sources. However, methanol dehydrogenase and 3-hexlose-6-phosphate synthase expression was regulated by methanol or formaldehyde; it were detected during growth and apparently differed from ribulose-1,5-bisphosphate carboxylase expression. These results suggested that A. methanolica MB58 may be initially dependent on autotrophic growth and that carbon assimilation was subsequently coupled with the ribulose monophosphate pathway at early- to mid-log phases during methylotrophic growth. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Latitudinal Trends in Stable Isotope Signatures of Northeast Atlantic Rhodoliths

NASA Astrophysics Data System (ADS)

Hofmann, Laurie

2017-04-01

Rhodoliths are free-living calcifying red algae that form extensive beds in shallow marine benthic environments (< 200 m) that provide important habitats and nurseries for marine organisms and contribute to carbonate sediment accumulation. There is growing concern that these organisms are sensitive to global climate change, which will have important consequences for coastal productivity and stability. Despite their significance and sensitivity, their basic photosynthetic and calcification mechanisms are not well understood. The goal of this study was to determine the plasticity of dissolved inorganic carbon (DIC) uptake mechanisms of rhodoliths along a latitudinal gradient in the Northeast (NE) Atlantic using natural stable isotope signatures. The delta 13C signature of macroalgae can be used to provide an indication of the preferred inorganic carbon source (CO2 vs. HCO3-). Here we present the total and organic delta 13C signatures of NE Atlantic rhodoliths with respect to changing temperature and light along the latitudinal gradient from the Canary Islands to Spitsbergen. A decreasing trend in delta 13C signatures with increasing latitude suggests that rhodoliths rely solely on CO2 as an inorganic carbon source at mid latitudes, while those at low latitudes may be able to utilize HCO3-. Polar rhodoliths deviate from this trend, suggesting they may have unique physiological mechanisms related to inorganic carbon acquisition and assimilation, which may have important implications for calcification in an environment undergoing rapid changing ocean chemistry.

The Denver Aerosol Sources and Health (DASH) Study: Overview and Early Findings

PubMed Central

Vedal, S.; Hannigan, M.P.; Dutton, S.J.; Miller, S. L.; Milford, J.B.; Rabinovitch, N.; Kim, S.-Y.; Sheppard, L.

2012-01-01

Improved understanding of the sources of air pollution that are most harmful could aid in developing more effective measures for protecting human health. The Denver Aerosol Sources and Health (DASH) study was designed to identify the sources of ambient fine particulate matter (PM2.5) that are most responsible for the adverse health effects of short-term exposure to PM 2.5. Daily 24-hour PM2.5 sampling began in July 2002 at a residential monitoring site in Denver, Colorado, using both Teflon and quartz filter samplers. Sampling is planned to continue through 2008. Chemical speciation is being carried out for mass, inorganic ionic compounds (sulfate, nitrate and ammonium), and carbonaceous components, including elemental carbon, organic carbon, temperature-resolved organic carbon fractions and a large array of organic compounds. In addition, water soluble metals were measured daily for 12 months in 2003. A receptor-based source apportionment approach utilizing positive matrix factorization (PMF) will be used to identify PM 2.5 source contributions for each 24-hour period. Based on a preliminary assessment using synthetic data, the proposed source apportionment should be able to identify many important sources on a daily basis, including secondary ammonium nitrate and ammonium sulfate, diesel vehicle exhaust, road dust, wood combustion and vegetative debris. Meat cooking, gasoline vehicle exhaust and natural gas combustion were more challenging for PMF to accurately identify due to high detection limits for certain organic molecular marker compounds. Measurements of these compounds are being improved and supplemented with additional organic molecular marker compounds. The health study will investigate associations between daily source contributions and an array of health endpoints, including daily mortality and hospitalizations and measures of asthma control in asthmatic children. Findings from the DASH study, in addition to being of interest to policymakers, by identifying harmful PM2.5 sources may provide insights into mechanisms of PM effect. PMID:22723735

The Denver Aerosol Sources and Health (DASH) study: Overview and early findings

NASA Astrophysics Data System (ADS)

Vedal, S.; Hannigan, M. P.; Dutton, S. J.; Miller, S. L.; Milford, J. B.; Rabinovitch, N.; Kim, S.-Y.; Sheppard, L.

Improved understanding of the sources of air pollution that are most harmful could aid in developing more effective measures for protecting human health. The Denver Aerosol Sources and Health (DASH) study was designed to identify the sources of ambient fine particulate matter (PM 2.5) that are most responsible for the adverse health effects of short-term exposure to PM 2.5. Daily 24-h PM 2.5 sampling began in July 2002 at a residential monitoring site in Denver, Colorado, using both Teflon and quartz filter samplers. Sampling is planned to continue through 2008. Chemical speciation is being carried out for mass, inorganic ionic compounds (sulfate, nitrate and ammonium), and carbonaceous components, including elemental carbon, organic carbon, temperature-resolved organic carbon fractions and a large array of organic compounds. In addition, water-soluble metals were measured daily for 12 months in 2003. A receptor-based source apportionment approach utilizing positive matrix factorization (PMF) will be used to identify PM 2.5 source contributions for each 24-h period. Based on a preliminary assessment using synthetic data, the proposed source apportionment should be able to identify many important sources on a daily basis, including secondary ammonium nitrate and ammonium sulfate, diesel vehicle exhaust, road dust, wood combustion and vegetative debris. Meat cooking, gasoline vehicle exhaust and natural gas combustion were more challenging for PMF to accurately identify due to high detection limits for certain organic molecular marker compounds. Measurements of these compounds are being improved and supplemented with additional organic molecular marker compounds. The health study will investigate associations between daily source contributions and an array of health endpoints, including daily mortality and hospitalizations and measures of asthma control in asthmatic children. Findings from the DASH study, in addition to being of interest to policymakers, by identifying harmful PM 2.5 sources may provide insights into mechanisms of PM effect.

Quantitative iTRAQ-based secretome analysis reveals species-specific and temporal shifts in carbon utilization strategies among manganese(II)-oxidizing Ascomycete fungi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zeiner, Carolyn A.; Purvine, Samuel O.; Zink, Erika M.

Fungi generate a wide range of extracellular hydrolytic and oxidative enzymes and reactive metabolites, collectively known as the secretome, that synergistically drive plant litter decomposition in the environment. While secretome studies of model organisms have greatly expanded our knowledge of these enzymes, few have extended secretome characterization to environmental isolates or directly compared temporal patterns of enzyme utilization among diverse species. Thus, the mechanisms of carbon (C) degradation by many ubiquitous soil fungi remain poorly understood. Here we use a combination of iTRAQ proteomics and custom bioinformatic analyses to compare the protein composition of the secretomes of four manganese(II)-oxidizing Ascomycetemore » fungi over a three-week time course. We demonstrate that although the fungi produce a similar suite of extracellular enzymes, they exhibit striking differences in the regulation of these enzymes among species and over time, revealing species-specific and temporal shifts in C utilization strategies as they degrade the same substrate. Specifically, our findings suggest that Paraconiothyrium sporulosum AP3s5-JAC2a and Alternaria alternata SRC1lrK2f employ sequential enzyme secretion patterns concomitant with decreasing resource availability, Stagonospora sp. SRC1lsM3a preferentially degrades proteinaceous substrate before switching to carbohydrates, and Pyrenochaeta sp. DS3sAY3a utilizes primarily peptidases to aggressively attack carbon sources in a concentrated burst. This work highlights the diversity of operative metabolic strategies among cellulose-degrading Ascomycetes and enhances our understanding of their role in C turnover in the environment.« less

Quantitative iTRAQ-based secretome analysis reveals species-specific and temporal shifts in carbon utilization strategies among manganese(II)-oxidizing Ascomycete fungi.

PubMed

Zeiner, Carolyn A; Purvine, Samuel O; Zink, Erika M; Paša-Tolić, Ljiljana; Chaput, Dominique L; Wu, Si; Santelli, Cara M; Hansel, Colleen M

2017-09-01

Fungi generate a wide range of extracellular hydrolytic and oxidative enzymes and reactive metabolites, collectively known as the secretome, that synergistically drive plant litter decomposition in the environment. While secretome studies of model organisms have greatly expanded our knowledge of these enzymes, few have extended secretome characterization to environmental isolates, particularly filamentous Ascomycetes, or directly compared temporal patterns of enzyme utilization among diverse species. Thus, the mechanisms of carbon (C) degradation by many ubiquitous soil fungi remain poorly understood. Here we use a combination of iTRAQ proteomics and extracellular enzyme activity assays to compare the protein composition of the secretomes of four manganese(II)-oxidizing Ascomycete fungi over a three-week time course. We demonstrate that the fungi exhibit striking differences in the regulation of extracellular lignocellulose-degrading enzymes among species and over time, revealing species-specific and temporal shifts in C utilization strategies as they degrade the same substrate. Specifically, our findings suggest that Alternaria alternata SRC1lrK2f and Paraconiothyrium sporulosum AP3s5-JAC2a employ sequential enzyme secretion patterns concomitant with decreasing resource availability. Stagonospora sp. SRC1lsM3a preferentially degrades proteinaceous substrate before switching to carbohydrates, and Pyrenochaeta sp. DS3sAY3a utilizes primarily peptidases to aggressively attack carbon sources in a concentrated burst. This work highlights the diversity of operative metabolic strategies among understudied yet ubiquitous cellulose-degrading Ascomycetes, enhancing our understanding of their contribution to C turnover in the environment. Copyright © 2017. Published by Elsevier Inc.

The Deletion of the Succinate Dehydrogenase Gene KlSDH1 in Kluyveromyces lactis Does Not Lead to Respiratory Deficiency

PubMed Central

Saliola, Michele; Bartoccioni, Paola Chiara; De Maria, Ilaria; Lodi, Tiziana; Falcone, Claudio

2004-01-01

We have isolated a Kluyveromyces lactis mutant unable to grow on all respiratory carbon sources with the exception of lactate. Functional complementation of this mutant led to the isolation of KlSDH1, the gene encoding the flavoprotein subunit of the succinate dehydrogenase (SDH) complex, which is essential for the aerobic utilization of carbon sources. Despite the high sequence conservation of the SDH genes in Saccharomyces cerevisiae and K. lactis, they do not have the same relevance in the metabolism of the two yeasts. In fact, unlike SDH1, KlSDH1 was highly expressed under both fermentative and nonfermentative conditions. In addition to this, but in contrast with S. cerevisiae, K. lactis strains lacking KlSDH1 were still able to grow in the presence of lactate. In these mutants, oxygen consumption was one-eighth that of the wild type in the presence of lactate and was normal with glucose and ethanol, indicating that the respiratory chain was fully functional. Northern analysis suggested that alternative pathway(s), which involves pyruvate decarboxylase and the glyoxylate cycle, could overcome the absence of SDH and allow (i) lactate utilization and (ii) the accumulation of succinate instead of ethanol during growth on glucose. PMID:15189981

Bacterial oxidation of dibromomethane and methyl bromide in natural waters and enrichment cultures

USGS Publications Warehouse

Goodwin, K.D.; Schaefer, J.K.; Oremland, R.S.

1998-01-01

Bacterial oxidation of 14CH2Br2 and 14CH3Br was measured in freshwater, estuarine, seawater, and hypersaline-alkaline samples. In general, bacteria from the various sites oxidized similar amounts of 14CH2Br2 and comparatively less 14CH3Br. Bacterial oxidation of 14CH3Br was rapid in freshwater samples compared to bacterial oxidation of 14CH3Br in more saline waters. Freshwater was also the only site in which methyl fluoride-sensitive bacteria (e.g., methanotrophs or nitrifiers) governed brominated methane oxidation. Half-life calculations indicated that bacterial oxidation of CH2Br2 was potentially significant in all of the waters tested. In contrast, only in freshwater was bacterial oxidation of CH3Br as fast as chemical removal. The values calculated for more saline sites suggested that bacterial oxidation of CH3Br was relatively slow compared to chemical and physical loss mechanisms. However, enrichment cultures demonstrated that bacteria in seawater can rapidly oxidize brominated methanes. Two distinct cultures of nonmethanotrophic methylotrophs were recovered; one of these cultures was able to utilize CH2Br2 as a sole carbon source, and the other was able to utilize CH3Br as a sole carbon source.

Xanthomonas oryzae pv. oryzae RpfE Regulates Virulence and Carbon Source Utilization without Change of the DSF Production

PubMed Central

Cho, Jung-Hee; Yoon, Joo-Mi; Lee, Sang-Won; Noh, Young-Hee; Cha, Jae-Soon

2013-01-01

It has been known that most regulation of pathogenicity factor (rpf) genes in xanthomonads regulates virulence in response to the diffusible signal factor, DSF. Although many rpf genes have been functionally characterized, the function of rpfE is still unknown. We cloned the rpfE gene from a Xanthomonas oryzae pv. oryzae (Xoo) Korean race KACC10859 and generated mutant strains to elucidate the role of RpfE with respect to the rpf system. Through experiments using the rpfE-deficient mutant strain, we found that mutation in rpfE gene in Xoo reduced virulence, swarm motility, and production of virulence factors such as cellulase and extracellular polysaccharide. Disease progress by the rpfE-deficient mutant strain was significantly slowed compared to disease progress by the wild type and the number of the rpfE-deficient mutant strain was lower than that of the wild type in the early phase of infection in the inoculated rice leaf. The rpfE mutant strain was unable to utilize sucrose or xylose as carbon sources efficiently in culture. The mutation in rpfE, however, did not affect DSF synthesis. Our results suggest that the rpfE gene regulates the virulence of Xoo under different nutrient conditions without change of DSF production. PMID:25288965

Microbial Community-Level Physiological Profiles (CLPP) and herbicide mineralization potential in groundwater affected by agricultural land use

NASA Astrophysics Data System (ADS)

Janniche, Gry Sander; Spliid, Henrik; Albrechtsen, Hans-Jørgen

2012-10-01

Diffuse groundwater pollution from agricultural land use may impact the microbial groundwater community, which was investigated as Community-Level Physiological Profiles (CLPP) using EcoPlate™. Water was sampled from seven piezometers and a spring in a small agricultural catchment with diffuse herbicide and nitrate pollution. Based on the Shannon-Wiener and Simpson's diversity indices the diversity in the microbial communities was high. The response from the EcoPlates™ showed which substrates support groundwater bacteria, and all 31 carbon sources were utilized by organisms from at least one water sample. However, only nine carbon sources were utilized by all water samples: D-Mannitol, N-acetyl-D-glucosamine, putrescine, D-galacturonic acid, itaconic acid, 4-hydroxy benzoic acid, tween 40, tween 80, and L-asparagine. In all water samples the microorganisms preferred D-mannitol, D-galacturonic acid, tween 40, and 4-hydroxy benzoic acid as substrates, whereas none preferred 2-hydroxy benzoic acid, α-D-lactose, D,L-α-glycerol phosphate, α-ketobutyric acid, L-threonine and glycyl-L-glutamic acid. Principal Component Analysis of the CLPP's clustered the most agriculturally affected groundwater samples, indicating that the agricultural land use affects the groundwater microbial communities. Furthermore, the ability to mineralize atrazine and isoproturon, which have been used in the catchment, was also associated with this cluster.

Construction of an alternative glycerol-utilization pathway for improved β-carotene production in Escherichia coli.

PubMed

Guo, Jin-Ying; Hu, Kun-Le; Bi, Chang-Hao; Li, Qing-Yan; Zhang, Xue-Li

2018-05-11

Glycerol, which is an inevitable by-product of biodiesel production, is an ideal carbon source for the production of carotenoids due to its low price, good availability and chemically reduced status, which results in a low requirement for additional reducing equivalents. In this study, an alternative carbon-utilization pathway was constructed in Escherichia coli to enable more efficient β-carotene production from glycerol. An aldehyde reductase gene (alrd) and an aldehyde dehydrogenase gene (aldH) from Ralstonia eutropha H16 were integrated into the E. coli chromosome to form a novel glycerol-utilization pathway. The β-carotene specific production value was increased by 50% after the introduction of alrd and aldH. It was found that the glycerol kinase gene (garK), alrd and aldH were the bottleneck of the alternative glycerol metabolic pathway, and modulation of garK gene with an mRS library further increased the β-carotene specific production value by 13%. Finally, co-modulation of genes in the introduced aldH-alrd operon led to 86% more of β-carotene specific production value than that of the strain without the alternative glycerol-utilization pathway and the glycerol-utilization rate was also increased. In this work, β-carotene production of E. coli was significantly improved by constructing and optimizing an alternative glycerol-utilization pathway. This strategy can potentially be used to improve the production of other isoprenoids using glycerol as a cheap and abundant substrate, and therefore has industrial relevance.

Detection of oxygen isotopic anomaly in terrestrial atmospheric carbonates and its implications to Mars.

PubMed

Shaheen, R; Abramian, A; Horn, J; Dominguez, G; Sullivan, R; Thiemens, Mark H

2010-11-23

The debate of life on Mars centers around the source of the globular, micrometer-sized mineral carbonates in the ALH84001 meteorite; consequently, the identification of Martian processes that form carbonates is critical. This paper reports a previously undescribed carbonate formation process that occurs on Earth and, likely, on Mars. We identified micrometer-sized carbonates in terrestrial aerosols that possess excess (17)O (0.4-3.9‰). The unique O-isotopic composition mechanistically describes the atmospheric heterogeneous chemical reaction on aerosol surfaces. Concomitant laboratory experiments define the transfer of ozone isotopic anomaly to carbonates via hydrogen peroxide formation when O(3) reacts with surface adsorbed water. This previously unidentified chemical reaction scenario provides an explanation for production of the isotopically anomalous carbonates found in the SNC (shergottites, nakhlaites, chassignites) Martian meteorites and terrestrial atmospheric carbonates. The anomalous hydrogen peroxide formed on the aerosol surfaces may transfer its O-isotopic signature to the water reservoir, thus producing mass independently fractionated secondary mineral evaporites. The formation of peroxide via heterogeneous chemistry on aerosol surfaces also reveals a previously undescribed oxidative process of utility in understanding ozone and oxygen chemistry, both on Mars and Earth.

Detection of oxygen isotopic anomaly in terrestrial atmospheric carbonates and its implications to Mars

PubMed Central

Shaheen, R.; Abramian, A.; Horn, J.; Dominguez, G.; Sullivan, R.; Thiemens, Mark H.

2010-01-01

The debate of life on Mars centers around the source of the globular, micrometer-sized mineral carbonates in the ALH84001 meteorite; consequently, the identification of Martian processes that form carbonates is critical. This paper reports a previously undescribed carbonate formation process that occurs on Earth and, likely, on Mars. We identified micrometer-sized carbonates in terrestrial aerosols that possess excess 17O (0.4–3.9‰). The unique O-isotopic composition mechanistically describes the atmospheric heterogeneous chemical reaction on aerosol surfaces. Concomitant laboratory experiments define the transfer of ozone isotopic anomaly to carbonates via hydrogen peroxide formation when O3 reacts with surface adsorbed water. This previously unidentified chemical reaction scenario provides an explanation for production of the isotopically anomalous carbonates found in the SNC (shergottites, nakhlaites, chassignites) Martian meteorites and terrestrial atmospheric carbonates. The anomalous hydrogen peroxide formed on the aerosol surfaces may transfer its O-isotopic signature to the water reservoir, thus producing mass independently fractionated secondary mineral evaporites. The formation of peroxide via heterogeneous chemistry on aerosol surfaces also reveals a previously undescribed oxidative process of utility in understanding ozone and oxygen chemistry, both on Mars and Earth. PMID:21059939

The provenance, formation, and implications of reduced carbon phases in Martian meteorites

NASA Astrophysics Data System (ADS)

Steele, Andrew; McCubbin, Francis M.; Fries, Marc D.

2016-11-01

This review is intended to summarize the current observations of reduced carbon in Martian meteorites, differentiating between terrestrial contamination and carbon that is indigenous to Mars. Indeed, the identification of Martian organic matter is among the highest priority targets for robotic spacecraft missions in the next decade, including the Mars Science Laboratory and Mars 2020. Organic carbon compounds are essential building blocks of terrestrial life, so the occurrence and origin (biotic or abiotic) of organic compounds on Mars is of great significance; however, not all forms of reduced carbon are conducive to biological systems. This paper discusses the significance of reduced organic carbon (including methane) in Martian geological and astrobiological systems. Specifically, it summarizes current thinking on the nature, sources, and sinks of Martian organic carbon, a key component to Martian habitability. Based on this compilation, reduced organic carbon on Mars, including detections of methane in the Martian atmosphere, is best described through a combination of abiotic organic synthesis on Mars and infall of extraterrestrial carbonaceous material. Although conclusive signs of Martian life have yet to be revealed, we have developed a strategy for life detection on Mars that can be utilized in future life-detection studies.

Can heterotrophic uptake of dissolved organic carbon and zooplankton mitigate carbon budget deficits in annually bleached corals?

NASA Astrophysics Data System (ADS)

Levas, Stephen; Grottoli, Andréa G.; Schoepf, Verena; Aschaffenburg, Matthew; Baumann, Justin; Bauer, James E.; Warner, Mark E.

2016-06-01

Annual coral bleaching events due to increasing sea surface temperatures are predicted to occur globally by the mid-century and as early as 2025 in the Caribbean, and severely impact coral reefs. We hypothesize that heterotrophic carbon (C) in the form of zooplankton and dissolved organic carbon (DOC) is a significant source of C to bleached corals. Thus, the ability to utilize multiple pools of fixed carbon and/or increase the amount of fixed carbon acquired from one or more pools of fixed carbon (defined here as heterotrophic plasticity) could underlie coral acclimatization and persistence under future ocean-warming scenarios. Here, three species of Caribbean coral— Porites divaricata, P. astreoides, and Orbicella faveolata—were experimentally bleached for 2.5 weeks in two successive years and allowed to recover in the field. Zooplankton feeding was assessed after single and repeat bleaching, while DOC fluxes and the contribution of DOC to the total C budget were determined after single bleaching, 11 months on the reef, and repeat bleaching. Zooplankton was a large C source for P. astreoides, but only following single bleaching. DOC was a source of C for single-bleached corals and accounted for 11-36 % of daily metabolic demand (CHARDOC), but represented a net loss of C in repeat-bleached corals. In repeat-bleached corals, DOC loss exacerbated the negative C budgets in all three species. Thus, the capacity for heterotrophic plasticity in corals is compromised under annual bleaching, and heterotrophic uptake of DOC and zooplankton does not mitigate C budget deficits in annually bleached corals. Overall, these findings suggest that some Caribbean corals may be more susceptible to repeat bleaching than to single bleaching due to a lack of heterotrophic plasticity, and coral persistence under increasing bleaching frequency may ultimately depend on other factors such as energy reserves and symbiont shuffling.

Production of a High Efficiency Microbial Flocculant by Proteus mirabilis TJ-1 Using Compound Organic Wastewater

NASA Astrophysics Data System (ADS)

Zhang, Zhiqiang; Xia, Siqing; Zhang, Jiao

2010-11-01

The production of a high efficiency microbial flocculant (MBF) by Proteus mirabilis TJ-1 using compound organic wastewater was investigated. To cut down the cost of the MBF production, several nutritive organic wastewaters were selected to replace glucose and peptone as the carbon source and the nitrogen source in the optimized medium of strain TJ-1, respectively. The compound wastewater of the milk candy and the soybean milk was found to be good carbon source and nitrogen source for this strain to produce MBF. The cost-effective culture medium consists of (per liter): 800 mL wastewater of milk candy, 200 mL wastewater of soybean milk, 0.3 g MgSO4ṡ7 H2O, 5 g K2HPO4, 2 g and KH2PO4, pH 7.0. The economic cost for the MBF production can be cut down over a half by using the developed culture medium. Furthermore, the utilization of the two wastewaters in the preparation of culture medium of strain TJ-1 can not only save their big treatment cost, but also realize their resource reuse.

Meeting China's electricity needs through clean energy sources: A 2030 low-carbon energy roadmap

NASA Astrophysics Data System (ADS)

Hu, Zheng

China is undergoing rapid economic development that generates significant increase in energy demand, primarily for electricity. Energy supply in China is heavily relying on coal, which leads to high carbon emissions. This dissertation explores opportunities for meeting China's growing power demand through clean energy sources. The utilization of China's clean energy sources as well as demand-side management is still at the initial phase. Therefore, development of clean energy sources would require substantial government support in order to be competitive in the market. One of the widely used means to consider clean energy in power sector supplying is Integrated Resource Strategic Planning, which aims to minimize the long term electricity costs while screening various power supply options for the power supply and demand analysis. The IRSP tool tackles the energy problem from the perspective of power sector regulators, and provides different policy scenarios to quantify the impacts of combined incentives. Through three scenario studies, Business as Usual, High Renewable, and Renewable and Demand Side Management, this dissertation identifies the optimized scenario for China to achieve the clean energy target of 2030. The scenarios are assessed through energy, economics, environment, and equity dimensions.

An alternative parameter to characterize biogas materials: Available carbon-nitrogen ratio.

PubMed

Wang, Ming; Li, Wenzhe; Li, Pengfei; Yan, Shuiping; Zhang, Yanlin

2017-04-01

Available carbon-nitrogen ratio (AC/N) was proposed as an alternative parameter for evaluating the potential of biogas materials in this paper. In the calculation of AC/N ratio, only the carbon that could be effectively utilized in anaerobic digestion (AD) process is included. Compared with total C/N, AC/N is particularly more suitable for the characterization of biogas materials rich in recalcitrant components. Nine common biogas materials were selected and a series of semi-continuous tests for up to 110days were carried out to investigate the source of available carbon and the relationship between AC/N and the stability of AD process. The results showed that only the carbon existing in proteins, sugars, fat and hemicelluose should be considered as available carbon for anaerobic microbes. Besides, the optimal AC/N for semi-continuous AD process was preliminarily determined to be 11-15. Taken together, our results demonstrate that AC/N is more effective than total C/N in the evaluation of the potential performance of AD process. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biocatalytic Desulfurization Capabilities of a Mixed Culture during Non-Destructive Utilization of Recalcitrant Organosulfur Compounds

PubMed Central

Ismail, Wael; El-Sayed, Wael S.; Abdul Raheem, Abdul Salam; Mohamed, Magdy E.; El Nayal, Ashraf M.

2016-01-01

We investigated the biodesulfurization potential of a mixed culture AK6 enriched from petroleum hydrocarbons-polluted soil with dibenzothiophene (DBT) as a sulfur source. In addition to DBT, AK6 utilized the following compounds as sulfur sources: 4-methyldibenzothiophene (4-MDBT), benzothiophene (BT), and 4,6- dimethyldibenzothiophene (4,6-DM-DBT). None of these compounds supported the growth of AK6 as the sole carbon and sulfur source. AK6 could not grow on dibenzylsulfide (DBS) as a sulfur source. The AK6 community structure changed according to the provided sulfur source. The major DGGE bands represented members of the genera Sphingobacterium, Klebsiella, Pseudomonas, Stenotrophomonas, Arthrobacter, Mycobacterium, and Rhodococcus. Sphingobacterium sp. and Pseudomonas sp. were abundant across all cultures utilizing any of the tested thiophenic S-compounds. Mycobacterium/Rhodococcus spp. were restricted to the 4-MDBT culture. The 4-MDBT culture had the highest species richness and diversity. Biodesulfurization of DBT by resting cells of AK6 produced 2-hydroxybiphenyl (2-HBP) in addition to trace amounts of phenylacetate. AK6 transformed DBT to 2-hydroxybiphenyl with a specific activity of 9 ± 0.6 μM 2-HBP g dry cell weight−1 h−1. PCR confirmed the presence in the AK6 community of the sulfur-specific (4S) pathway genes dszB and dszC. Mixed cultures hold a better potential than axenic ones for the development of a biodesulfurization technology. PMID:26973637

Enhanced biological phosphorus removal in a sequencing batch reactor using propionate as the sole carbon source.

PubMed

Pijuan, M; Saunders, A M; Guisasola, A; Baeza, J A; Casas, C; Blackall, L L

2004-01-05

An enhanced biological phosphorus removal (EBPR) system was developed in a sequencing batch reactor (SBR) using propionate as the sole carbon source. The microbial community was followed using fluorescence in situ hybridization (FISH) techniques and Candidatus 'Accumulibacter phosphatis' were quantified from the start up of the reactor until steady state. A series of SBR cycle studies was performed when 55% of the SBR biomass was Accumulibacter, a confirmed polyphosphate accumulating organism (PAO) and when Candidatus 'Competibacter phosphatis', a confirmed glycogen-accumulating organism (GAO), was essentially undetectable. These experiments evaluated two different carbon sources (propionate and acetate), and in every case, two different P-release rates were detected. The highest rate took place while there was volatile fatty acid (VFA) in the mixed liquor, and after the VFA was depleted a second P-release rate was observed. This second rate was very similar to the one detected in experiments performed without added VFA.A kinetic and stoichiometric model developed as a modification of Activated Sludge Model 2 (ASM2) including glycogen economy, was fitted to the experimental profiles. The validation and calibration of this model was carried out with the cycle study experiments performed using both VFAs. The effect of pH from 6.5 to 8.0 on anaerobic P-release and VFA-uptake and aerobic P-uptake was also studied using propionate. The optimal overall working pH was around 7.5. This is the first study of the microbial community involved in EBPR developed with propionate as a sole carbon source along with detailed process performance investigations of the propionate-utilizing PAOs. Copyright 2003 Wiley Periodicals, Inc.

The use of solar energy can enhance the conversion of carbon dioxide into energy-rich products: stepping towards artificial photosynthesis.

PubMed

Aresta, Michele; Dibenedetto, Angela; Angelini, Antonella

2013-08-13

The need to cut CO₂ emission into the atmosphere is pushing scientists and technologists to discover and implement new strategies that may be effective for controlling the CO₂ atmospheric level (and its possible effects on climate change). One option is the capture of CO₂ from power plant flue gases or other industrial processes to avoid it entering the atmosphere. The captured CO₂ can be either disposed in natural fields (geological cavities, spent gas or oil wells, coal beads, aquifers; even oceans have been proposed) or used as a source of carbon in synthetic processes. In this paper, we present the options for CO₂ utilization and make an analysis of possible solutions for the conversion of large volumes of CO₂ by either combining it with H₂, that must be generated from water, or by directly converting it into fuels by electrolysis in water using solar energy. A CO₂-H₂-based economy may address the issue of reducing the environmental burden of energy production, also saving fossil carbon for future generations. The integration of CO₂ capture and utilization with CO₂ capture and storage would result in a more economically and energetically viable practice of CO₂ capture.

Investigating human responses to political and environmental change through paleodiet and paleomobility.

PubMed

Knudson, Kelly J; Torres-Rouff, Christina; Stojanowski, Christopher M

2015-06-01

Bioarchaeological approaches are well suited for examining past responses to political and environmental changes. In the Andes, we hypothesized that political and environmental changes around AD 1100 resulted in behavioral changes, visible as shifts in paleodiet and paleomobility, among individuals in the San Pedro de Atacama oases and Loa River Valley. To investigate this hypothesis, we generated carbon and oxygen isotope data from cemeteries dating to the early Middle Horizon (Larache, Quitor-5, Solor-3), late Middle Horizon (Casa Parroquial, Coyo Oriental, Coyo-3, Solcor-Plaza, Solcor-3, Tchecar), and Late Intermediate Period (Caspana, Quitor-6 Tardío, Toconce, Yaye-1, Yaye-2, Yaye-3, Yaye-4). Carbon isotope data demonstrate a greater range of carbon sources during the late Middle Horizon compared with the Late Intermediate Period; while most individuals consumed largely C3 sources, some late Middle Horizon individuals consumed more C4 sources. Oxygen isotope data demonstrate greater diversity in drinking water sources during the late Middle Horizon compared with the Late Intermediate Period. Water samples were analyzed to provide baseline data on oxygen isotope variability within the Atacama Desert, and demonstrated that oxygen isotope values are indistinguishable in the San Pedro and Loa Rivers. However, oxygen isotope values in water sources in the high-altitude altiplano and coast are distinct from those in the San Pedro and Loa Rivers. In conclusion, instead of utilizing a wider variety of resources after environmental and political changes, individuals exhibited a wider range of paleodietary and paleomobility strategies during the Middle Horizon, a period of environmental and political stability. © 2015 Wiley Periodicals, Inc.

Multifunctional carbon nanoelectrodes fabricated by focused ion beam milling.

PubMed

Thakar, Rahul; Weber, Anna E; Morris, Celeste A; Baker, Lane A

2013-10-21

We report a strategy for fabrication of sub-micron, multifunctional carbon electrodes and application of these electrodes as probes for scanning electrochemical microscopy (SECM) and scanning ion conductance microscopy (SICM). The fabrication process utilized chemical vapor deposition of parylene, followed by thermal pyrolysis to form conductive carbon and then further deposition of parylene to form an insulation layer. To achieve well-defined electrode geometries, two methods of electrode exposure were utilized. In the first method, carbon probes were masked in polydimethylsiloxane (PDMS) to obtain a cone-shaped electrode. In the second method, the electrode area was exposed via milling with a focused ion beam (FIB) to reveal a carbon ring electrode, carbon ring/platinum disk electrode, or carbon ring/nanopore electrode. Carbon electrodes were batch fabricated (~35/batch) through the vapor deposition process and were characterized with scanning electron microscopy (SEM), scanning transmission electron microscopy (STEM), and cyclic voltammetry (CV) measurements. Additionally, Raman spectroscopy was utilized to examine the effects of Ga(+) ion implantation, a result of FIB milling. Constant-height, feedback mode SECM was performed with conical carbon electrodes and carbon ring electrodes. We demonstrate the utility of carbon ring/nanopore electrodes with SECM-SICM to simultaneously collect topography, ion current and electrochemical current images. In addition, carbon ring/nanopore electrodes were utilized in substrate generation/tip collection (SG/TC) SECM. In SG/TC SECM, localized delivery of redox molecules affords a higher resolution, than when the redox molecules are present in the bath solution. Multifunctional geometries of carbon electrode probes will find utility in electroanalytical applications, in general, and more specifically with electrochemical microscopy as discussed herein.

Microorganism Utilization for Synthetic Milk

NASA Technical Reports Server (NTRS)

Morford, Megan A.; Khodadad, Christina L.; Caro, Janicce I.; Spencer, LaShelle E.; Richards, Jeffery T.; Strayer, Richard F.; Birmele, Michele N.; Wheeler, Raymond M.

2014-01-01

A desired architecture for long duration spaceflight, like aboard the International Space Station or for future missions to Mars, is to provide a supply of fresh food crops for the astronauts. However, some crops can create a high proportion of inedible plant waste. The main goal of the Synthetic Biology project, Cow in a Column, was to produce the components of milk (sugar, lipid, protein) from inedible plant waste by utilizing microorganisms (fungi, yeast, bacteria). Of particular interest was utilizing the valuable polysaccharide, cellulose, found in plant waste, to naturally fuel-through microorganism cellular metabolism- the creation of sugar (glucose), lipid (milk fat), and protein (casein) in order to produce a synthetic edible food product. Environmental conditions such as pH, temperature, carbon source, aeration, and choice microorganisms were optimized in the laboratory and the desired end-products, sugars and lipids, were analyzed. Trichoderma reesei, a known cellulolytic fungus, was utilized to drive the production of glucose, with the intent that the produced glucose would serve as the carbon source for milk fat production and be a substitute for the milk sugar lactose. Lipid production would be carried out by Rhodosporidium toruloides, yeast known to accumulate those lipids that are typically found in milk fat. Results showed that glucose and total lipid content were below what was expected during this phase of experimentation. In addition, individual analysis of six fatty acids revealed that the percentage of each fatty acid was lower than naturally produced bovine milk. Overall, this research indicates that microorganisms could be utilized to breakdown inedible solid waste to produce useable products. For future work, the production of the casein protein for milk would require the development of a genetically modified organism, which was beyond the scope of the original project. Additional trials would be needed to further refine the required environment/organisms for the production of desired sugar and lipid end-products.

Climate Change Effects of Forest Management and Substitution of Carbon-Intensive Materials and Fossil Fuels

NASA Astrophysics Data System (ADS)

Sathre, R.; Gustavsson, L.; Haus, S.; Lundblad, M.; Lundström, A.; Ortiz, C.; Truong, N.; Wikberg, P. E.

2016-12-01

Forests can play several roles in climate change mitigation strategies, for example as a reservoir for storing carbon and as a source of renewable materials and energy. To better understand the linkages and possible trade-offs between different forest management strategies, we conduct an integrated analysis where both sequestration of carbon in growing forests and the effects of substituting carbon intensive products within society are considered. We estimate the climate effects of directing forest management in Sweden towards increased carbon storage in forests, with more land set-aside for protection, or towards increased forest production for the substitution of carbon-intensive materials and fossil fuels, relative to a reference case of current forest management. We develop various scenarios of forest management and biomass use to estimate the carbon balances of the forest systems, including ecological and technological components, and their impacts on the climate in terms of cumulative radiative forcing over a 100-year period. For the reference case of current forest management, increasing the harvest of forest residues is found to give increased climate benefits. A scenario with increased set-aside area and the current level of forest residue harvest begins with climate benefits compared to the reference scenario, but the benefits cannot be sustained for 100 years because the rate of carbon storage in set-aside forests diminishes over time as the forests mature, but the demand for products and fuels remains. The most climatically beneficial scenario, expressed as reduced cumulative radiative forcing, in both the short and long terms is a strategy aimed at high forest production, high residue recovery rate, and high efficiency utilization of harvested biomass. Active forest management with high harvest level and efficient forest product utilization will provide more climate benefit, compared to reducing harvest and storing more carbon in the forest. Figure. Schematic diagram of complete modelled forest system including ecological and technological components, showing major flows of carbon.

Impact of seawater carbonate chemistry on the calcification of marine bivalves

NASA Astrophysics Data System (ADS)

Thomsen, J.; Haynert, K.; Wegner, K. M.; Melzner, F.

2015-07-01

Bivalve calcification, particularly of the early larval stages, is highly sensitive to the change in ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32-] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the exact carbonate system component by which growth and calcification are affected it is necessary to utilize more complex carbonate chemistry manipulations. As single factors, pCO2 had no effects and [HCO3-] and pH had only limited effects on shell growth, while lowered [CO32-] strongly impacted calcification. Dissolved inorganic carbon (CT) limiting conditions led to strong reductions in calcification, despite high [CO32-], indicating that [HCO3-] rather than [CO32-] is the inorganic carbon source utilized for calcification by mytilid mussels. However, as the ratio [HCO3-] / [H+] is linearly correlated with [CO32-] it is not possible to differentiate between these under natural seawater conditions. An equivalent of about 80 μmol kg-1 [CO32-] is required to saturate inorganic carbon supply for calcification in bivalves. Below this threshold biomineralization rates rapidly decline. A comparison of literature data available for larvae and juvenile mussels and oysters originating from habitats differing substantially with respect to prevailing carbonate chemistry conditions revealed similar response curves. This suggests that the mechanisms which determine sensitivity of calcification in this group are highly conserved. The higher sensitivity of larval calcification seems to primarily result from the much higher relative calcification rates in early life stages. In order to reveal and understand the mechanisms that limit or facilitate adaptation to future ocean acidification, it is necessary to better understand the physiological processes and their underlying genetics that govern inorganic carbon assimilation for calcification.

Impact of seawater carbonate chemistry on the calcification of marine bivalves

NASA Astrophysics Data System (ADS)

Thomsen, J.; Haynert, K.; Wegner, K. M.; Melzner, F.

2015-01-01

Bivalve calcification, particular of the early larval stages is highly sensitive to the change of ocean carbonate chemistry resulting from atmospheric CO2 uptake. Earlier studies suggested that declining seawater [CO32-] and thereby lowered carbonate saturation affect shell production. However, disturbances of physiological processes such as acid-base regulation by adverse seawater pCO2 and pH can affect calcification in a secondary fashion. In order to determine the exact carbonate system component by which growth and calcification are affected it is necessary to utilize more complex carbonate chemistry manipulations. As single factors, pCO2 had no and [HCO3-] and pH only limited effects on shell growth, while lowered [CO32-] strongly impacted calcification. Dissolved inorganic carbon (CT) limiting conditions led to strong reductions in calcification, despite high [CO32-], indicating that [HCO3-] rather than [CO32-] is the inorganic carbon source utilized for calcification by mytilid mussels. However, as the ratio [HCO3-] / [H+] is linearly correlated with [CO32-] it is not possible to differentiate between these under natural seawater conditions. Therefore, the availability of [HCO3-] combined with favorable environmental pH determines calcification rate and an equivalent of about 80 μmol kg-1 [CO32-] is required to saturate inorganic carbon supply for calcification in bivalves. Below this threshold biomineralization rates rapidly decline. A comparison of literature data available for larvae and juvenile mussels and oysters originating from habitats differing substantially with respect to prevailing carbonate chemistry conditions revealed similar response curves. This suggests that the mechanisms which determine sensitivity of calcification in this group are highly conserved. The higher sensitivity of larval calcification seems to primarily result from the much higher relative calcification rates in early life stages. In order to reveal and understand the mechanisms that limit or facilitate adaptation to future ocean acidification, it is necessary to better understand the physiological processes and their underlying genetics that govern inorganic carbon assimilation for calcification.

Metabolic Engineering of Corynebacterium glutamicum for Methanol Metabolism

PubMed Central

Witthoff, Sabrina; Schmitz, Katja; Niedenführ, Sebastian; Nöh, Katharina; Noack, Stephan

2015-01-01

Methanol is already an important carbon feedstock in the chemical industry, but it has found only limited application in biotechnological production processes. This can be mostly attributed to the inability of most microbial platform organisms to utilize methanol as a carbon and energy source. With the aim to turn methanol into a suitable feedstock for microbial production processes, we engineered the industrially important but nonmethylotrophic bacterium Corynebacterium glutamicum toward the utilization of methanol as an auxiliary carbon source in a sugar-based medium. Initial oxidation of methanol to formaldehyde was achieved by heterologous expression of a methanol dehydrogenase from Bacillus methanolicus, whereas assimilation of formaldehyde was realized by implementing the two key enzymes of the ribulose monophosphate pathway of Bacillus subtilis: 3-hexulose-6-phosphate synthase and 6-phospho-3-hexuloisomerase. The recombinant C. glutamicum strain showed an average methanol consumption rate of 1.7 ± 0.3 mM/h (mean ± standard deviation) in a glucose-methanol medium, and the culture grew to a higher cell density than in medium without methanol. In addition, [13C]methanol-labeling experiments revealed labeling fractions of 3 to 10% in the m + 1 mass isotopomers of various intracellular metabolites. In the background of a C. glutamicum Δald ΔadhE mutant being strongly impaired in its ability to oxidize formaldehyde to CO2, the m + 1 labeling of these intermediates was increased (8 to 25%), pointing toward higher formaldehyde assimilation capabilities of this strain. The engineered C. glutamicum strains represent a promising starting point for the development of sugar-based biotechnological production processes using methanol as an auxiliary substrate. PMID:25595770

Proteiniborus ethanoligenes gen. nov., sp. nov., an anaerobic protein-utilizing bacterium.

PubMed

Niu, Lili; Song, Lei; Dong, Xiuzhu

2008-01-01

A novel anaerobic, mesophilic, protein-utilizing bacterial strain, GW(T), was isolated from the mesophilic hydrogen-producing granular sludge used to treat food industry wastewater. The strain was a Gram-positive, non-spore-forming and non-motile rod. Growth of the strain was observed at 20-48 degrees C and at pH 6.4-10.0. The strain used yeast extract and peptone as carbon and energy sources. Weak growth was also observed with tryptone and Casamino acids as carbon and energy sources. The strain used none of the tested carbohydrates, alcohols or fatty acids. The fermentation products in peptone-yeast broth included ethanol, acetic acid, hydrogen and carbon dioxide. Gelatin was not hydrolysed. Nitrate was reduced. Indole was produced. NH(3) and H(2)S were not produced. The DNA G+C content of strain GW(T) was 38.0 mol%. The predominant cellular fatty acids were the saturated fatty acids C(14:0) (15.58%), C(16:0) (25.40%) and C(18:0) (12.03%). Phylogenetic analysis based on 16S rRNA gene sequence similarity revealed that strain GW(T) represented a new branch within cluster XII of the Clostridium subphylum, with <89.6% 16S rRNA gene sequence similarities to all described species. On the basis of polyphasic evidence from this study, strain GW(T) represents a new genus and novel species, for which the name Proteiniborus ethanoligenes gen. nov., sp. nov. is proposed. The type strain is GW(T) (=CGMCC 1.5055(T)=JCM 14574(T)).

Carbon source and energy harvesting optimization in solid anolyte microbial fuel cells

NASA Astrophysics Data System (ADS)

Adekunle, Ademola; Raghavan, Vijaya; Tartakovsky, Boris

2017-07-01

This work investigates the application of a solid anolyte microbial fuel cell (saMFC) as a long-lasting source of electricity for powering electronic devices. Broadly available biodegradable materials such as humus, cattle manure, peat moss, and sawdust are evaluated as solid anolytes. The initial comparison shows significantly higher power production in the saMFC operated using humus as compared to other solid anolytes. At the same time, power production in the humus-based saMFC is found to decline after about 40 days of operation, while the sawdust MFC demonstrates stable performance over the test period. Following this initial comparison, a combined humus - sawdust anolyte is developed to increase saMFC life span. The optimized saMFC demonstrates stable power production for over nine months. Furthermore, power production in the saMFC is maximized by using an intermittent connection to an electrical load (on/off operation) and optimizing the connection/disconnection times. These results demonstrate the feasibility of utilizing solid anolytes for developing inexpensive and long-lasting biobatteries operated on renewable carbon sources.

Molecular Signatures of Microbial Metabolism in an Actively Growing, Silicified, Microbial Structure from Yellowstone National Park

NASA Astrophysics Data System (ADS)

Ferreira, M.; Creveling, J.; Hilburn, I.; Karlsson, E.; Pepe-Ranney, C.; Spear, J.; Dawson, S.; Geobio2008, I.

2008-12-01

Silicified structures that exhibit a putative biologic component in their formation permeate the rock record as stromatolites. We have studied a silicified microbial structure from a hot spring in Yellowstone National Park using phenotypic, phylogenetic, and metagenomic analyses to determine microbial carbon metabolic pathways and the phylogenetic affiliations of microbes present in this unique structure. In this multi-faceted approach, dominant physiologies, specifically with regards to anaerobic and aerobic metabolisms, were inferred from 16S rRNA gene sequences and 454 sequencing data from bulk DNA samples of the structure. Carbon utilization as indicated by ECO Biolog plates showed abundant heterotrophy and heterotrophic diversity throughout the microbial structure. Microbes within the structure are able to utilize all tested sources of carbohydrates, lipids/fatty acids, and protein/amino acids as carbon sources. ECO plate testing of the hot spring water yielded considerable less carbohydrate consumption (only 4 out of 13 tested carbohydrates) and similar lipids/fatty acids and protein/amino acids consumption (2 out of 3 and 5 out of 5 tested sources respectively). Full length 16S rRNA gene sequences and metagenomic 454 pyrosequencing of community DNA showed limited diversity among primary producers. From the 16S data, the majority of the autotrophs are inferred to utilize the Calvin cycle for CO2 fixation, followed by 3-hydroxypropionate/4- hydroxybutyrate CO2 fixation. However, an analysis of the metagenomic data compared to the KEGG database does not show genes directly involved with Calvin cycle carbon fixation. Further BLAST searches of our data failed to find significant matches within our 6514 metagenomic sequences to known RuBisCo sequences taken from the NCBI database. This is likely due to a far under-sampled dataset of metagenomic sequences, and the low number (958) that had matches to the KEGG pathways database. Anaerobic versus aerobic physiology also can be estimated from the 16S clone libraries. Phylogenetic analysis of recovered 16S sequences suggests that 15% of the 16S sequences can be attributed to anaerobic microbes while 42% likely come from aerobes. The remaining 43% of 16S rRNA gene sequences belong to metabolically unassigned phyla both known and novel. This preliminary study demonstrates that the small spatially stratified silicified microbial structure present on the margins of a hot spring contains a rich and complex microbial community with different trophic levels and enzymatic pathways.

Design Constraints on a Synthetic Metabolism

PubMed Central

Bilgin, Tugce; Wagner, Andreas

2012-01-01

A metabolism is a complex network of chemical reactions that converts sources of energy and chemical elements into biomass and other molecules. To design a metabolism from scratch and to implement it in a synthetic genome is almost within technological reach. Ideally, a synthetic metabolism should be able to synthesize a desired spectrum of molecules at a high rate, from multiple different nutrients, while using few chemical reactions, and producing little or no waste. Not all of these properties are achievable simultaneously. We here use a recently developed technique to create random metabolic networks with pre-specified properties to quantify trade-offs between these and other properties. We find that for every additional molecule to be synthesized a network needs on average three additional reactions. For every additional carbon source to be utilized, it needs on average two additional reactions. Networks able to synthesize 20 biomass molecules from each of 20 alternative sole carbon sources need to have at least 260 reactions. This number increases to 518 reactions for networks that can synthesize more than 60 molecules from each of 80 carbon sources. The maximally achievable rate of biosynthesis decreases by approximately 5 percent for every additional molecule to be synthesized. Biochemically related molecules can be synthesized at higher rates, because their synthesis produces less waste. Overall, the variables we study can explain 87 percent of variation in network size and 84 percent of the variation in synthesis rate. The constraints we identify prescribe broad boundary conditions that can help to guide synthetic metabolism design. PMID:22768162

Mechanisms for hydrogen production by different bacteria during mixed-acid and photo-fermentation and perspectives of hydrogen production biotechnology.

PubMed

Trchounian, Armen

2015-03-01

H2 has a great potential as an ecologically-clean, renewable and capable fuel. It can be mainly produced via hydrogenases (Hyd) by different bacteria, especially Escherichia coli and Rhodobacter sphaeroides. The operation direction and activity of multiple Hyd enzymes in E. coli during mixed-acid fermentation might determine H2 production; some metabolic cross-talk between Hyd enzymes is proposed. Manipulating the activity of different Hyd enzymes is an effective way to enhance H2 production by E. coli in biotechnology. Moreover, a novel approach would be the use of glycerol as feedstock in fermentation processes leading to H2 production. Mixed carbon (sugar and glycerol) utilization studies enlarge the kind of organic wastes used in biotechnology. During photo-fermentation under limited nitrogen conditions, H2 production by Rh. sphaeroides is observed when carbon and nitrogen sources are supplemented. The relationship of H2 production with H(+) transport across the membrane and membrane-associated ATPase activity is shown. On the other hand, combination of carbon sources (succinate, malate) with different nitrogen sources (yeast extract, glutamate, glycine) as well as different metal (Fe, Ni, Mg) ions might regulate H2 production. All these can enhance H2 production yield by Rh. sphaeroides in biotechnology Finally, two of these bacteria might be combined to develop and consequently to optimize two stages of H2 production biotechnology with high efficiency transformation of different organic sources.

Synthetic Klebsiella pneumoniae-Shewanella oneidensis Consortium Enables Glycerol-Fed High-Performance Microbial Fuel Cells.

PubMed

Li, Feng; Yin, Changji; Sun, Liming; Li, Yuanxiu; Guo, Xuewu; Song, Hao

2018-05-01

Microbial fuel cell (MFC) is an eco-friendly bio-electrochemical sys-tem that uses microorganism as biocatalyst to convert biomass into electricity. Glycerol, as a waste in the biodiesel refinery processes, is an appealing substrate for MFC. Nevertheless, glycerol cannot be utilized as carbon source by well-known exoelectrogens such as Shewanella oneidensis. Herein, to generate electricity by rapidly harnessing glycerol, the authors rationally constructed a Klebsiella pneumoniae-Shewanella oneidensis microbial consortium to efficiently harvest electricity from glyc-erol, in which K. pneumoniae converted glycerol into lactate, fed to S. oneidensis as carbon source and electron donor. To improve electricity output, the authors systematically engineered the consortium in terms of carbon flux distribution and efficiency of extracellular electron transfer (EET). To direct more carbon flux to lactate biosynthesis in K. pneumoniae, the authors eliminated the ethanol pathway by knocking out the alcohol dehydrogenase gene (adhE), and enhanced lactate biosynthesis by heterologously expressing a lactate dehydrogen-ase gene (ldhD) from Lactobacillus bulgaricus and a lactate transporter gene (lldP) from Escherichia coli. To facilitate EET between S. oneidensis and anode surfaces, a biosynthetic flavins pathway from Bacillus subtilis is introduced into S. oneidensis. The author further optimized the glycerol concentration, thus S. oneidensis could be continuously fed with lactate synthesized from K. pneumoniae at a constant rate. Our glycerol-fed MFC generated a maximum power density of 19.9 mW/m 2 , significantly higher than that of the wild-type consor-tium. This work suggested that engineering microbial consortia is an effi-cient strategy to expand the spectrum of usable carbon sources and promote electricity power production in MFCs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomass-derived heteroatoms-doped mesoporous carbon for efficient oxygen reduction in microbial fuel cells.

PubMed

Lu, Yu; Zhu, Nengwu; Yin, Fuhua; Yang, Tingting; Wu, Pingxiao; Dang, Zhi; Liu, Meilin; Wei, Xiaorong

2017-12-15

Currently, the development of less expensive, more active and more stable catalysts like heteroatom-doped carbon based non-precious metal materials are highly desired for the cathodic oxygen reduction reaction (ORR) in microbial fuel cells (MFCs). Comparing with heteroatom sources from chemical reagents, biomass is notably inexpensive and abundant, containing more elements which contribute to ORR activity. Herein, we demonstrate an easy operating one-step and low-cost way to synthesize egg-derived heteroatoms-doped mesoporous carbon (EGC) catalysts utilizing egg as the biomass carbon and other elements source (sulphur, phosphorus, boron and iron), and porous g-C 3 N 4 as both template and nitrogen source. After carbonized, such hybrid materials possess an outstanding electrocatalytic activity towards ORR comparable to the commercial Pt/C catalyst in neutral media. Electrochemical detections as cyclic voltammogram and rotating ring-disk electrode tests show that the potential of oxygen reduction peak of EGC1-10-2 is at + 0.10V, onset potential is at + 0.257V (vs. Ag/AgCl) and electron transfer number of that is 3.84-3.92, which indicate that EGC1-10-2 via a four-electron pathway. Reactor operation shows that the maximum power density of MFC-EGC1-10-2 (737.1mWm -2 ), which is slightly higher than MFC-Pt/C (20%) (704mWm -2 ). The low cost (0.049 $g -1 ), high yield (20.26%) and high performance of EGC1-10-2 provide a promising alternative to noble metal catalysts by using abundant natural biological resources, which contribute a lot to expansion and commercialization of MFCs. Copyright © 2017 Elsevier B.V. All rights reserved.

Production of branched-chain alcohols by recombinant Ralstonia eutropha in fed-batch cultivation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fei, Q; Brigham, CJ; Lu, JN

Branched-chain alcohols are considered promising green energy sources due to their compatibility with existing infrastructure and their high energy density. We utilized a strain of Ralstonia eutropha capable of producing branched-chain alcohols and examined its production in flask cultures. In order to increase isobutanol and 3-methyl-1-butanol (isoamyl alcohol) productivity in the engineered strain, batch, fed-batch, and two-stage fed-batch cultures were carried out in this work. The effects of nitrogen source concentration on branched-chain alcohol production were investigated under four different initial concentrations in fermenters. A maximum 380 g m(-3) of branched-chain alcohol production was observed with 2 kg m(-3) initialmore » NH4Cl concentration in batch cultures. A pH-stat control strategy was utilized to investigate the optimum carbon source amount fed during fed-batch cultures for higher cell density. In cultures of R. eutropha strains that did not produce polyhydroxyalkanoate or branched-chain alcohols, a maximum cell dry weight of 36 kg m(-3) was observed using a fed-batch strategy, when 10 kg m(-3) carbon source was fed into culture medium. Finally, a total branched-chain alcohol titer of 790 g m(-3), the highest branched-chain alcohol yield of 0.03 g g(-1), and the maximum branched-chain alcohol productivity of 8.23 g m(-3) h(-1) were obtained from the engineered strain Re2410/pJL26 in a two-stage fed-batch culture system with pH-stat control. Isobutanol made up over 95% (mass fraction) of the total branched-chain alcohols titer produced in this study. (C) 2013 Published by Elsevier Ltd.« less

Simultaneous consumption of pentose and hexose sugars: an optimal microbial phenotype for efficient fermentation of lignocellulosic biomass.

PubMed

Kim, Jae-Han; Block, David E; Mills, David A

2010-11-01

Lignocellulosic biomass is an attractive carbon source for bio-based fuel and chemical production; however, its compositional heterogeneity hinders its commercial use. Since most microbes possess carbon catabolite repression (CCR), mixed sugars derived from the lignocellulose are consumed sequentially, reducing the efficacy of the overall process. To overcome this barrier, microbes that exhibit the simultaneous consumption of mixed sugars have been isolated and/or developed and evaluated for the lignocellulosic biomass utilization. Specific strains of Escherichia coli, Saccharomyces cerevisiae, and Zymomonas mobilis have been engineered for simultaneous glucose and xylose utilization via mutagenesis or introduction of a xylose metabolic pathway. Other microbes, such as Lactobacillus brevis, Lactobacillus buchneri, and Candida shehatae possess a relaxed CCR mechanism, showing simultaneous consumption of glucose and xylose. By exploiting CCR-negative phenotypes, various integrated processes have been developed that incorporate both enzyme hydrolysis of lignocellulosic material and mixed sugar fermentation, thereby enabling greater productivity and fermentation efficacy.

Simultaneous consumption of pentose and hexose sugars: an optimal microbial phenotype for efficient fermentation of lignocellulosic biomass

PubMed Central

Kim, Jae-Han; Block, David E.

2010-01-01

Lignocellulosic biomass is an attractive carbon source for bio-based fuel and chemical production; however, its compositional heterogeneity hinders its commercial use. Since most microbes possess carbon catabolite repression (CCR), mixed sugars derived from the lignocellulose are consumed sequentially, reducing the efficacy of the overall process. To overcome this barrier, microbes that exhibit the simultaneous consumption of mixed sugars have been isolated and/or developed and evaluated for the lignocellulosic biomass utilization. Specific strains of Escherichia coli, Saccharomyces cerevisiae, and Zymomonas mobilis have been engineered for simultaneous glucose and xylose utilization via mutagenesis or introduction of a xylose metabolic pathway. Other microbes, such as Lactobacillus brevis, Lactobacillus buchneri, and Candida shehatae possess a relaxed CCR mechanism, showing simultaneous consumption of glucose and xylose. By exploiting CCR-negative phenotypes, various integrated processes have been developed that incorporate both enzyme hydrolysis of lignocellulosic material and mixed sugar fermentation, thereby enabling greater productivity and fermentation efficacy. PMID:20838789

Enantiomeric Degradation of 2-(4-Sulfophenyl)Butyrate via 4-Sulfocatechol in Delftia acidovorans SPB1

PubMed Central

Schulz, Saskia; Dong, Wenbo; Groth, Ulrich; Cook, Alasdair M.

2000-01-01

Enrichment cultures with enantiomeric 2-(4-sulfophenyl)butyrate (SPB) as the sole added source(s) of carbon and energy for growth yielded a pure culture of a degradative bacterium, which was identified as Delftia acidovorans SPB1. The organism utilized the enantiomers sequentially. R-SPB was utilized first (specific growth rate [μ] = 0.28 h−1), with transient excretion of an unknown intermediate, which was identified as 4-sulfocatechol (4SC). Utilization of S-SPB was slower (μ = 0.016 h−1) and was initiated only after the first enantiomer was exhausted. Suspensions of cells grown in S-SPB excreted 4SC, so metabolism of the two enantiomers converged at 4SC. The latter was degraded by ortho cleavage via 3-sulfo-cis,cis-muconate. Strain SPB1 grew with 4SC and with 1-(4-sulfophenyl)octane (referred to herein as model LAS) but not with commercial linear alkylbenzenesulfonate (LAS) surfactant, which is subterminally substituted but nontoxic. It would appear that metabolism of the model LAS does not represent metabolism of commercial LAS. PMID:10788358

Kinetics of substrate utilization and bacterial growth of crude oil degraded by Pseudomonas aeruginosa.

PubMed

Talaiekhozani, Amirreza; Jafarzadeh, Nematollah; Fulazzaky, Mohamad Ali; Talaie, Mohammad Reza; Beheshti, Masoud

2015-01-01

Pollution associated with crude oil (CO) extraction degrades the quality of waters, threatens drinking water sources and may ham air quality. The systems biology approach aims at learning the kinetics of substrate utilization and bacterial growth for a biological process for which very limited knowledge is available. This study uses the Pseudomonas aeruginosa to degrade CO and determines the kinetic parameters of substrate utilization and bacterial growth modeled from a completely mixed batch reactor. The ability of Pseudomonas aeruginosa can remove 91 % of the total petroleum hydrocarbons and 83 % of the aromatic compounds from oily environment. The value k of 9.31 g of substrate g(-1) of microorganism d(-1) could be far higher than the value k obtained for petrochemical wastewater treatment and that for municipal wastewater treatment. The production of new cells of using CO as the sole carbon and energy source can exceed 2(3) of the existing cells per day. The kinetic parameters are verified to contribute to improving the biological removal of CO from oily environment.

An atomic carbon source for high temperature molecular beam epitaxy of graphene.

PubMed

Albar, J D; Summerfield, A; Cheng, T S; Davies, A; Smith, E F; Khlobystov, A N; Mellor, C J; Taniguchi, T; Watanabe, K; Foxon, C T; Eaves, L; Beton, P H; Novikov, S V

2017-07-26

We report the use of a novel atomic carbon source for the molecular beam epitaxy (MBE) of graphene layers on hBN flakes and on sapphire wafers at substrate growth temperatures of ~1400 °C. The source produces a flux of predominantly atomic carbon, which diffuses through the walls of a Joule-heated tantalum tube filled with graphite powder. We demonstrate deposition of carbon on sapphire with carbon deposition rates up to 12 nm/h. Atomic force microscopy measurements reveal the formation of hexagonal moiré patterns when graphene monolayers are grown on hBN flakes. The Raman spectra of the graphene layers grown on hBN and sapphire with the sublimation carbon source and the atomic carbon source are similar, whilst the nature of the carbon aggregates is different - graphitic with the sublimation carbon source and amorphous with the atomic carbon source. At MBE growth temperatures we observe etching of the sapphire wafer surface by the flux from the atomic carbon source, which we have not observed in the MBE growth of graphene with the sublimation carbon source.

Effects of iron and calcium carbonate on the variation and cycling of carbon source in integrated wastewater treatments.

PubMed

Zhimiao, Zhao; Xinshan, Song; Yufeng, Zhao; Yanping, Xiao; Yuhui, Wang; Junfeng, Wang; Denghua, Yan

2017-02-01

Iron and calcium carbonate were added in wastewater treatments as the adjusting agents to improve the contaminant removal performance and regulate the variation of carbon source in integrated treatments. At different temperatures, the addition of the adjusting agents obviously improved the nitrogen and phosphorous removals. TN and TP removals were respectively increased by 29.41% and 23.83% in AC-100 treatment under 1-day HRT. Carbon source from dead algae was supplied as green microbial carbon source and Fe 2+ was supplied as carbon source surrogate. COD concentration was increased to 30mg/L and above, so the problem of the shortage of carbon source was solved. Dead algae and Fe 2+ as carbon source supplement or surrogate played significant role, which was proved by microbial community analysis. According to the denitrification performance in the treatments, dead algae as green microbial carbon source combined with iron and calcium carbonate was the optimal supplement carbon source in wastewater treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis, characterization and potential utility of doped ceramics based catalysts

NASA Astrophysics Data System (ADS)

Sharma, Ritika; Yadav, Deepshikha; Singh, G. P.; Vyas, G.; Bhojak, N.

2018-05-01

Excessive utilization of petrol, diesel and other fossil fuels, continuous increase in their prices, and the big problem of carbon dioxide mission have encouraged scientists and technologist to find either new sources of energy or to develop technologies for the sustainable utilization of fuel. Biofuels are the only energy technologies that can resolve the problem of carbon dioxide emission in the atmosphere as well as reduce the amount of fossil fuel burned. Bio ethanol and biodiesel are the most common types of biofuel which are being used at present. Biodiesel has become more interesting for all the researchers in present scenario. Various feedstock viz. edible, nonedible oils, waste cooking oil, animal fat, algae etc, are using for the production of biodiesel worldwide according to their availability. Selection of efficient heterogeneous catalysts for biodiesel preparation still needs more attention of researchers. The present investigation deals with determination of synthesis, characterization and applications of doped ceramic based materials in different medium. Two of doped ceramic based catalysts which has been potentially used for the production of biodiesel. The Engine performance of biodiesel samples, made from industrial waste oils and ceramic based catalyst, have also been investigated and found up to satisfactory levels.

Fabrication and application of advanced functional materials from lignincellulosic biomass

NASA Astrophysics Data System (ADS)

Hu, Sixiao

This dissertation explored the conversion of lignocellulosic biomass into advanced functional materials and their potential applications. Lignocellulosic biomass represents an as-of-yet underutilized renewable source for not only biofuel production but also functional materials fabrication. This renewable source is a great alternative for fossil fuel based chemicals, which could be one of the solutions to energy crisis. In this work, it was demonstrated a variety of advanced materials including functional carbons, metal and silica nanoparticles could be derived from lignocellulosic biomass. Chapter 1 provided overall reviewed of the lignin structures, productions and its utilizations as plastics, absorbents and carbons, as well as the preparation of nano-structured silver, silica and silicon carbide/nitride from biomass. Chapter 2, 3 and 4 discussed the fabrication of highly porous carbons from isolated lignin, and their applications as electric supercapacitors for energy storage. In chapter 2, ultrafine porous carbon fibers were prepared via electrospinning followed by simultaneous carbonization and activation. Chapter 3 covered the fabrication of supercapacitor based on the porous carbon fibers and the investigation of their electrochemical performances. In chapter 4, porous carbon particulates with layered carbon nano plates structures were produced by simple oven-drying followed by simultaneous carbonization and activation. The effects of heat processing parameters on the resulting carbon structures and their electrochemical properties were discussed in details. Chapter 5 and 6 addressed the preparation of silver nanoparticles using lignin. Chapter 5 reported the synthesis, underlying kinetics and mechanism of monodispersed silver nanospheres with diameter less than 25 nm in aqueous solutions using lignin as dual reducing and capping agents. Chapter 6 covered the preparation of silver nanoparticles on electrospun celluloses ultrafine fibers using lignin as both binding and reducing agents. The efficiency of this synthetic protocol and the properties of resulting particles were examined. Chapter 7 reported the streamlined extraction of lignin/hemicelluloses and silica from rice straw and their subsequent conversion to activated carbon and monodispersed silica particles.

Enhanced biological phosphorus removal with different carbon sources.

PubMed

Shen, Nan; Zhou, Yan

2016-06-01

Enhanced biological phosphorus removal (EBPR) process is one of the most economical and sustainable methods for phosphorus removal from wastewater. However, the performance of EBPR can be affected by available carbon sources types in the wastewater that may induce different functional microbial communities in the process. Glycogen accumulating organisms (GAOs) and polyphosphate accumulating organisms (PAOs) are commonly found by coexisting in the EBPR process. Predominance of GAO population may lead to EBPR failure due to the competition on carbon source with PAO without contributing phosphorus removal. Carbon sources indeed play an important role in alteration of PAOs and GAOs in EBPR processes. Various types of carbon sources have been investigated for EBPR performance. Certain carbon sources tend to enrich specific groups of GAOs and/or PAOs. This review summarizes the types of carbon sources applied in EBPR systems and highlights the roles of these carbon sources in PAO and GAO competition. Both single (e.g., acetate, propionate, glucose, ethanol, and amino acid) and complex carbon sources (e.g., yeast extract, peptone, and mixed carbon sources) are discussed in this review. Meanwhile, the environmental friendly and economical carbon sources that are derived from waste materials, such as crude glycerol and wasted sludge, are also discussed and compared.

PRELIMINARY ENVIRONMENTAL, HEALTH AND SAFETY RISK ASSESSMENT ON THE INTEGRATION OF A PROCESS UTILIZING LOW-ENERGY SOLVENTS FOR CARBON DIOXIDE CAPTURE ENABLED BY A COMBINATION OF ENZYMES AND VACUUM REGENERATION WITH A SUBCRITICAL PC POWER PLANT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fitzgerald, David; Vidal, Rafael; Russell, Tania

2014-12-31

The results of the preliminary environmental, health and safety (EH&S) risk assessment for an enzyme-activated potassium carbonate (K2CO3) solution post-combustion CO2 capture (PCC) plant, integrated with a subcritical pulverized coal (PC) power plant, are presented. The expected emissions during normal steady-state operation have been estimated utilizing models of the PCC plant developed in AspenTech’s AspenPlus® software, bench scale test results from the University of Kentucky, and industrial experience of emission results from a slipstream PCC plant utilizing amine based solvents. A review of all potential emission species and their sources was undertaken that identified two credible emission sources, the absorbermore » off-gas that is vented to atmosphere via a stack and the waste removed from the PCC plant in the centrifuge used to reclaim enzyme and solvent. The conditions and compositions of the emissions were calculated and the potential EH&S effects were considered as well as legislative compliance requirements. Potential mitigation methods for emissions during normal operation have been proposed and solutions to mitigate uncontrolled releases of species have been considered. The potential emissions were found to pose no significant EH&S concerns and were compliant with the Federal legislation reviewed. The limitations in predicting full scale plant performance from bench scale tests have been noted and further work on a larger scale test unit is recommended to reduce the level of uncertainty.« less

Fast synthesis of multilayer carbon nanotubes from camphor oil as an energy storage material.

PubMed

TermehYousefi, Amin; Bagheri, Samira; Shinji, Kawasaki; Rouhi, Jalal; Rusop Mahmood, Mohamad; Ikeda, Shoichiro

2014-01-01

Among the wide range of renewable energy sources, the ever-increasing demand for electricity storage represents an emerging challenge. Utilizing carbon nanotubes (CNTs) for energy storage is closely being scrutinized due to the promising performance on top of their extraordinary features. In this work, well-aligned multilayer carbon nanotubes were successfully synthesized on a porous silicon (PSi) substrate in a fast process using renewable natural essential oil via chemical vapor deposition (CVD). Considering the influx of vaporized multilayer vertical carbon nanotubes (MVCNTs) to the PSi, the diameter distribution increased as the flow rate decreased in the reactor. Raman spectroscopy results indicated that the crystalline quality of the carbon nanotubes structure exhibits no major variation despite changes in the flow rate. Fourier transform infrared (FT-IR) spectra confirmed the hexagonal structure of the carbon nanotubes because of the presence of a peak corresponding to the carbon double bond. Field emission scanning electron microscopy (FESEM) images showed multilayer nanotubes, each with different diameters with long and straight multiwall tubes. Moreover, the temperature programmed desorption (TPD) method has been used to analyze the hydrogen storage properties of MVCNTs, which indicates that hydrogen adsorption sites exist on the synthesized multilayer CNTs.

Fast Synthesis of Multilayer Carbon Nanotubes from Camphor Oil as an Energy Storage Material

PubMed Central

TermehYousefi, Amin; Bagheri, Samira; Shinji, Kawasaki; Rouhi, Jalal; Rusop Mahmood, Mohamad; Ikeda, Shoichiro

2014-01-01

Among the wide range of renewable energy sources, the ever-increasing demand for electricity storage represents an emerging challenge. Utilizing carbon nanotubes (CNTs) for energy storage is closely being scrutinized due to the promising performance on top of their extraordinary features. In this work, well-aligned multilayer carbon nanotubes were successfully synthesized on a porous silicon (PSi) substrate in a fast process using renewable natural essential oil via chemical vapor deposition (CVD). Considering the influx of vaporized multilayer vertical carbon nanotubes (MVCNTs) to the PSi, the diameter distribution increased as the flow rate decreased in the reactor. Raman spectroscopy results indicated that the crystalline quality of the carbon nanotubes structure exhibits no major variation despite changes in the flow rate. Fourier transform infrared (FT-IR) spectra confirmed the hexagonal structure of the carbon nanotubes because of the presence of a peak corresponding to the carbon double bond. Field emission scanning electron microscopy (FESEM) images showed multilayer nanotubes, each with different diameters with long and straight multiwall tubes. Moreover, the temperature programmed desorption (TPD) method has been used to analyze the hydrogen storage properties of MVCNTs, which indicates that hydrogen adsorption sites exist on the synthesized multilayer CNTs. PMID:25258714

Optical and Scratch Resistant Properties of Diamondlike Carbon Films Deposited with Single and Dual Ion Beams

NASA Technical Reports Server (NTRS)

Kussmaul, Michael T.; Bogdanski, Michael S.; Banks, Bruce A.; Mirtich, Michael J.

1993-01-01

Amorphous diamond-like carbon (DLC) films were deposited using both single and dual ion beam techniques utilizing filament and hollow cathode ion sources. Continuous DLC films up to 3000 A thick were deposited on fused quartz plates. Ion beam process parameters were varied in an effort to create hard, clear films. Total DLC film absorption over visible wavelengths was obtained using a Perkin-Elmer spectrophotometer. An ellipsometer, with an Ar-He laser (wavelength 6328 A) was used to determine index of refraction for the DLC films. Scratch resistance, frictional, and adherence properties were determined for select films. Applications for these films range from military to the ophthalmic industries.

Optical and scratch resistant properties of diamondlike carbon films deposited with single and dual ion beams

NASA Technical Reports Server (NTRS)

Kussmaul, Michael T.; Bogdanski, Michael S.; Banks, Bruce A.; Mirtich, Michael J.

1993-01-01

Amorphous diamondlike carbon (DLC) films were deposited using both single and dual ion beam techniques utilizing filament and hollow cathode ion sources. Continuous DLC films up to 3000 A thick were deposited on fused quartz plates. Ion beam process parameters were varied in an effort to create hard, clear films. Total DLC film absorption over visible wavelengths was obtained using a Perkin-Elmer spectrophotometer. An ellipsometer, with an Ar-He laser (wavelength 6328 A) was used to determine index of refraction for the DLC films. Scratch resistance and frictional and adherence properties were determined for select films. Applications for these films range from military to the ophthalmic industries.

Genomic and Transcriptomic Resolution of Organic Matter Utilization Among Deep-Sea Bacteria in Guaymas Basin Hydrothermal Plumes.

PubMed

Li, Meng; Jain, Sunit; Dick, Gregory J

2016-01-01

Microbial chemosynthesis within deep-sea hydrothermal vent plumes is a regionally important source of organic carbon to the deep ocean. Although chemolithoautotrophs within hydrothermal plumes have attracted much attention, a gap remains in understanding the fate of organic carbon produced via chemosynthesis. In the present study, we conducted shotgun metagenomic and metatranscriptomic sequencing on samples from deep-sea hydrothermal vent plumes and surrounding background seawaters at Guaymas Basin (GB) in the Gulf of California. De novo assembly of metagenomic reads and binning by tetranucleotide signatures using emergent self-organizing maps (ESOM) revealed 66 partial and nearly complete bacterial genomes. These bacterial genomes belong to 10 different phyla: Actinobacteria, Bacteroidetes, Chloroflexi, Deferribacteres, Firmicutes, Gemmatimonadetes, Nitrospirae, Planctomycetes, Proteobacteria, Verrucomicrobia. Although several major transcriptionally active bacterial groups (Methylococcaceae, Methylomicrobium, SUP05, and SAR324) displayed methanotrophic and chemolithoautotrophic metabolisms, most other bacterial groups contain genes encoding extracellular peptidases and carbohydrate metabolizing enzymes with significantly higher transcripts in the plume than in background, indicating they are involved in degrading organic carbon derived from hydrothermal chemosynthesis. Among the most abundant and active heterotrophic bacteria in deep-sea hydrothermal plumes are Planctomycetes, which accounted for seven genomes with distinct functional and transcriptional activities. The Gemmatimonadetes and Verrucomicrobia also had abundant transcripts involved in organic carbon utilization. These results extend our knowledge of heterotrophic metabolism of bacterial communities in deep-sea hydrothermal plumes.

Genomic and Transcriptomic Resolution of Organic Matter Utilization Among Deep-Sea Bacteria in Guaymas Basin Hydrothermal Plumes

PubMed Central

Li, Meng; Jain, Sunit; Dick, Gregory J.

2016-01-01

Microbial chemosynthesis within deep-sea hydrothermal vent plumes is a regionally important source of organic carbon to the deep ocean. Although chemolithoautotrophs within hydrothermal plumes have attracted much attention, a gap remains in understanding the fate of organic carbon produced via chemosynthesis. In the present study, we conducted shotgun metagenomic and metatranscriptomic sequencing on samples from deep-sea hydrothermal vent plumes and surrounding background seawaters at Guaymas Basin (GB) in the Gulf of California. De novo assembly of metagenomic reads and binning by tetranucleotide signatures using emergent self-organizing maps (ESOM) revealed 66 partial and nearly complete bacterial genomes. These bacterial genomes belong to 10 different phyla: Actinobacteria, Bacteroidetes, Chloroflexi, Deferribacteres, Firmicutes, Gemmatimonadetes, Nitrospirae, Planctomycetes, Proteobacteria, Verrucomicrobia. Although several major transcriptionally active bacterial groups (Methylococcaceae, Methylomicrobium, SUP05, and SAR324) displayed methanotrophic and chemolithoautotrophic metabolisms, most other bacterial groups contain genes encoding extracellular peptidases and carbohydrate metabolizing enzymes with significantly higher transcripts in the plume than in background, indicating they are involved in degrading organic carbon derived from hydrothermal chemosynthesis. Among the most abundant and active heterotrophic bacteria in deep-sea hydrothermal plumes are Planctomycetes, which accounted for seven genomes with distinct functional and transcriptional activities. The Gemmatimonadetes and Verrucomicrobia also had abundant transcripts involved in organic carbon utilization. These results extend our knowledge of heterotrophic metabolism of bacterial communities in deep-sea hydrothermal plumes. PMID:27512389

Enhanced Ionization Of Propellant Through Carbon Nanotube Growth On Angled Walls

DTIC Science & Technology

2017-06-01

FEEP field emission electric propulsion MUF mass utilization factor NSTAR NASA Solar Technology Application Readiness SCATHA Spacecraft Charging at...Experiments This experiment, Spacecraft Charging at High Altitudes (SCATHA), was developed by the U.S. Air Force along with NASA [5]. A satellite was launched...propulsion system, gimbal mounted and deployed on DS1. Source: [6]. 3. DAWN A more recent use of XIPS is the DAWN Spacecraft from NASA . Orbiting the

Synthesis of porous carbon nanofiber with bamboo-like carbon nanofiber branches by one-step carbonization process

NASA Astrophysics Data System (ADS)

Yoo, Seung Hwa; Joh, Han-Ik; Lee, Sungho

2017-04-01

Porous carbon nanofibers (PCNFs) with CNF branches (PCNF/bCNF) were synthesized by a simple heat treatment method. Conventional methods to synthesize this unique structure usually follow a typical route, which consists of CNF preparation, catalyst deposition, and secondary CNF growth. In contrast, our method utilized a one-step carbonization process of polymer nanofibers, which were electrospun from a one-pot solution consisted of polyacrylonitrile, polystyrene (PS), and iron acetylacetonate. Various structures of PCNF/CNF were synthesized by changing the solution composition and molecular weight of PS. It was verified that the content and molecular weight of PS were critical for the growth of catalyst particles and subsequent growth of CNF branches. The morphology, phase of catalyst, and carbon structure of PCNF/bCNF were analyzed at different temperature steps during carbonization. It was found that pores were generated by the evaporation of PS and the catalyst particles were formed on the surface of PCNF at 700 °C. The gases originated from the evaporation of PS acted as a carbon source for the growth of CNF branches that started at 900 °C. Finally, when the carbonization process was finished at 1200 °C, uniform and abundant CNF branches were formed on the surface of PCNF.

Biodegradation of alkaline lignin by Bacillus ligniniphilus L1

DOE PAGES

Zhu, Daochen; Zhang, Peipei; Xie, Changxiao; ...

2017-02-21

Lignin is the most abundant aromatic biopolymer in the biosphere and it comprises up to 30% of plant biomass. Although lignin is the most recalcitrant component of the plant cell wall, still there are microorganisms able to decompose it or degrade it. Fungi are recognized as the most widely used microbes for lignin degradation. However, bacteria have also been known to be able to utilize lignin as a carbon or energy source. Bacillus ligniniphilus L1 was selected in this study due to its capability to utilize alkaline lignin as a single carbon or energy source and its excellent ability tomore » survive in extreme environments. To investigate the aromatic metabolites of strain L1 decomposing alkaline lignin, GC–MS analysis was performed and fifteen single phenol ring aromatic compounds were identified. The dominant absorption peak included phenylacetic acid, 4-hydroxy-benzoicacid, and vanillic acid with the highest proportion of metabolites resulting in 42%. Comparison proteomic analysis was carried out for further study showed that approximately 1447 kinds of proteins were produced, 141 of which were at least twofold up-regulated with alkaline lignin as the single carbon source. The up-regulated proteins contents different categories in the biological functions of protein including lignin degradation, ABC transport system, environmental response factors, protein synthesis, assembly, etc. In conclusion, GC–MS analysis showed that alkaline lignin degradation of strain L1 produced 15 kinds of aromatic compounds. Comparison proteomic data and metabolic analysis showed that to ensure the degradation of lignin and growth of strain L1, multiple aspects of cells metabolism including transporter, environmental response factors, and protein synthesis were enhanced. Based on genome and proteomic analysis, at least four kinds of lignin degradation pathway might be present in strain L1, including a Gentisate pathway, the benzoic acid pathway and the β-ketoadipate pathway. The study provides an important basis for lignin degradation by bacteria.« less

Biodegradation of alkaline lignin by Bacillus ligniniphilus L1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Daochen; Zhang, Peipei; Xie, Changxiao

Background: Lignin is the most abundant aromatic biopolymer in the biosphere and it comprises up to 30% of plant biomass. Although lignin is the most recalcitrant component of the plant cell wall, still there are microorganisms able to decompose it or degrade it. Fungi are recognized as the most widely used microbes for lignin degradation. However, bacteria have also been known to be able to utilize lignin as a carbon or energy source. Bacillus ligniniphilus L1 was selected in this study due to its capability to utilize alkaline lignin as a single carbon or energy source and its excellent abilitymore » to survive in extreme environments. Results: To investigate the aromatic metabolites of strain L1 decomposing alkaline lignin, GC-MS analyze was performed and fifteen single phenol ring aromatic compounds were identified. The dominant absorption peak included phenylacetic acid, 4-hydroxy-benzoicacid, and vanillic acid with the highest proportion of metabolites resulting in 42%. Comparison proteomic analysis were carried out for further study showed that approximately 1447 kinds of proteins were produced, 141 of which were at least 2-fold up-regulated with alkaline lignin as the single carbon source. The up-regulated proteins contents different categories in the biological functions of protein including lignin degradation, ABC transport system, environmental response factors, protein synthesis and assembly, etc. Conclusions: GC-MS analysis showed that alkaline lignin degradation of strain L1 produced 15 kinds of aromatic compounds. Comparison proteomic data and metabolic analysis showed that to ensure the degradation of lignin and growth of strain L1, multiple aspects of cells metabolism including transporter, environmental response factors, and protein synthesis were enhanced. Based on genome and proteomic analysis, at least four kinds of lignin degradation pathway might be present in strain L1, including a Gentisate pathway, the benzoic acid pathway and the β-ketoadipate pathway. The study provides an important basis for lignin degradation by bacteria.« less

Biodegradation of alkaline lignin by Bacillus ligniniphilus L1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Daochen; Zhang, Peipei; Xie, Changxiao

Lignin is the most abundant aromatic biopolymer in the biosphere and it comprises up to 30% of plant biomass. Although lignin is the most recalcitrant component of the plant cell wall, still there are microorganisms able to decompose it or degrade it. Fungi are recognized as the most widely used microbes for lignin degradation. However, bacteria have also been known to be able to utilize lignin as a carbon or energy source. Bacillus ligniniphilus L1 was selected in this study due to its capability to utilize alkaline lignin as a single carbon or energy source and its excellent ability tomore » survive in extreme environments. To investigate the aromatic metabolites of strain L1 decomposing alkaline lignin, GC–MS analysis was performed and fifteen single phenol ring aromatic compounds were identified. The dominant absorption peak included phenylacetic acid, 4-hydroxy-benzoicacid, and vanillic acid with the highest proportion of metabolites resulting in 42%. Comparison proteomic analysis was carried out for further study showed that approximately 1447 kinds of proteins were produced, 141 of which were at least twofold up-regulated with alkaline lignin as the single carbon source. The up-regulated proteins contents different categories in the biological functions of protein including lignin degradation, ABC transport system, environmental response factors, protein synthesis, assembly, etc. In conclusion, GC–MS analysis showed that alkaline lignin degradation of strain L1 produced 15 kinds of aromatic compounds. Comparison proteomic data and metabolic analysis showed that to ensure the degradation of lignin and growth of strain L1, multiple aspects of cells metabolism including transporter, environmental response factors, and protein synthesis were enhanced. Based on genome and proteomic analysis, at least four kinds of lignin degradation pathway might be present in strain L1, including a Gentisate pathway, the benzoic acid pathway and the β-ketoadipate pathway. The study provides an important basis for lignin degradation by bacteria.« less

Assessing the potential of amino acid 13C patterns as a carbon source tracer in marine sediments: effects of algal growth conditions and sedimentary diagenesis

NASA Astrophysics Data System (ADS)

Larsen, T.; Bach, L. T.; Salvatteci, R.; Wang, Y. V.; Andersen, N.; Ventura, M.; McCarthy, M. D.

2015-08-01

Burial of organic carbon in marine sediments has a profound influence in marine biogeochemical cycles and provides a sink for greenhouse gases such as CO2 and CH4. However, tracing organic carbon from primary production sources as well as its transformations in the sediment record remains challenging. Here we examine a novel but growing tool for tracing the biosynthetic origin of amino acid carbon skeletons, based on naturally occurring stable carbon isotope patterns in individual amino acids (δ13CAA). We focus on two important aspects for δ13CAA utility in sedimentary paleoarchives: first, the fidelity of source diagnostic of algal δ13CAA patterns across different oceanographic growth conditions, and second, the ability of δ13CAA patterns to record the degree of subsequent microbial amino acid synthesis after sedimentary burial. Using the marine diatom Thalassiosira weissflogii, we tested under controlled conditions how δ13CAA patterns respond to changing environmental conditions, including light, salinity, temperature, and pH. Our findings show that while differing oceanic growth conditions can change macromolecular cellular composition, δ13CAA isotopic patterns remain largely invariant. These results emphasize that δ13CAA patterns should accurately record biosynthetic sources across widely disparate oceanographic conditions. We also explored how δ13CAA patterns change as a function of age, total nitrogen and organic carbon content after burial, in a marine sediment core from a coastal upwelling area off Peru. Based on the four most informative amino acids for distinguishing between diatom and bacterial sources (i.e., isoleucine, lysine, leucine and tyrosine), bacterially derived amino acids ranged from 10 to 15 % in the sediment layers from the last 5000 years, and up to 35 % during the last glacial period. The greater bacterial contributions in older sediments indicate that bacterial activity and amino acid resynthesis progressed, approximately as a function of sediment age, to a substantially larger degree than suggested by changes in total organic nitrogen and carbon content. It is uncertain whether archaea may have contributed to sedimentary δ13CAA patterns we observe, and controlled culturing studies will be needed to investigate whether δ13CAA patterns can differentiate bacterial from archeal sources. Further research efforts are also needed to understand how closely δ13CAA patterns derived from hydrolyzable amino acids represent total sedimentary proteineincous material, and more broadly sedimentary organic nitrogen. Overall, however, both our culturing and sediment studies suggest that δ13CAA patterns in sediments will represent a novel proxy for understanding both primary production sources, and the direct bacterial role in the ultimate preservation of sedimentary organic matter.

Microbial Community Shifts due to Hydrofracking: Observations from Field-Scale Observations and Laboratory-Scale Incubations

NASA Astrophysics Data System (ADS)

Mouser, P. J.; Ansari, M.; Hartsock, A.; Lui, S.; Lenhart, J.

2012-12-01

The use of fluids containing chemicals and variable water sources during the hydrofracking of unconventional shale is the source of considerable controversy due to perceived risks from altered subsurface biogeochemistry and the potential for contaminating potable water supplies. Rapid shifts in subsurface biogeochemistry are often driven by available macronutrients combined with the abundance and metabolic condition of the subsurface microbiota. While the depth that fracturing occurs in the Marcellus formation is reasonably deep to pose little risk to groundwater supplies, no published studies have systematically characterized the indigenous microbial population and how this community is altered through variable fluid management practices (e.g., chemical composition, source water makeup). In addition, limited information is available on how shallower microbial communities and geochemical conditions might be affected through the accidental release of these fluids to groundwater aquifers. Our measurements indicate field-applied and laboratory-generated fracking fluids contain levels of organic carbon greater than 300 mg/l and nitrogen concentrations greater than 80 mg/l that may differentially stimulate microbial growth in subsurface formations. In contrast to certain inorganic constituents (e.g., chloride) which increase in concentration through the flowback period; dissolved organic carbon levels decrease with time after the fracturing process through multiple attenuation processes (dilution, sorption, microbial utilization). Pyrosequencing data of the 16S rRNA gene indicate a shift from a more diverse source water microbial community to a less diverse community typical of a brine formation as time after fracturing increases. The introduction of varying percentages of a laboratory-generated fracking fluid to microcosm bottles containing groundwater and aquifer media stimulated biogeochemical changes similar to the introduction of landfill leachate, another wastewater containing elevated carbon, nitrogen, and complex organic constituents (e.g., decreased redox conditions, stepwise utilization of available terminal electron acceptors, enriched Fe(II) and sulfide concentrations). These research findings are important for understanding how fluids used during shale energy development may alter in situ microbial communities and provide insight into processes that attenuate the migration of these fluids in shallow aquifers and deep shale formations.

Enhanced carbon monoxide utilization in methanation process

DOEpatents

Elek, Louis F.; Frost, Albert C.

1984-01-01

Carbon monoxide - containing gas streams are passed over a catalyst to deposit a surface layer of active surface carbon thereon essentially without the formation of inactive coke. The active carbon is subsequently reacted with steam or hydrogen to form methane. Surprisingly, hydrogen and water vapor present in the feed gas do not adversely affect CO utilization significantly, and such hydrogen actually results in a significant increase in CO utilization.

Factors shaping bacterial phylogenetic and functional diversity in coastal waters of the NW Mediterranean Sea

NASA Astrophysics Data System (ADS)

Boras, Julia A.; Vaqué, Dolors; Maynou, Francesc; Sà, Elisabet L.; Weinbauer, Markus G.; Sala, Maria Montserrat

2015-03-01

To evaluate the main factors shaping bacterioplankton phylogenetic and functional diversity in marine coastal waters, we carried out a two-year study based on a monthly sampling in Blanes Bay (NW Mediterranean). We expected the key factors driving bacterial diversity to be (1) temperature and nutrient concentration, together with chlorophyll a concentration as an indicator of phytoplankton biomass and, hence, a carbon source for bacteria (here called bottom-up factors), and (2) top-down pressure (virus- and protist-mediated mortality of bacteria). Phylogenetic diversity was analyzed by denaturing gradient gel electrophoresis (DGGE) of 16S rRNA. Functional diversity was assessed by using monomeric carbon sources in Biolog EcoPlates and by determining the activity of six extracellular enzymes. Our results indicate that the bacterial phylogenetic and functional diversity in this coastal system is shaped mainly by bottom-up factors. A dendrogram analysis of the DGGE banding patterns revealed three main sample clusters. Two clusters differed significantly in temperature, nitrate and chlorophyll a concentration, and the third was characterized by the highest losses of bacterial production due to viral lysis detected over the whole study period. Protistan grazing had no effect on bacterial functional diversity, since there were no correlations between protist-mediated mortality (PMM) and extracellular enzyme activities, and utilization of only two out of the 31 carbon sources (N-acetyl-D-glucosamine and α-cyclodextrin) was correlated with PMM. In contrast, virus-mediated mortality correlated with changes in the percentage of use of four carbon sources, and also with specific leu-aminopeptidase and β-glucosidase activity. This suggests that viral lysate provides a pool of labile carbon sources, presumably including amino acids and glucose, which may inhibit proteolytic and glucosidic activity. Our results indicate that bottom-up factors play a more important role than top-down factors (i.e. viral lysis and protistan grazing) in shaping bacterial community structure and activity. Furthermore, they suggest that viruses play a more important role than protists in modifying community structure and functional diversity of bacteria in oligotrophic marine coastal waters.

Identification and Characterization of Oleaginous Yeast Isolated from Kefir and Its Ability to Accumulate Intracellular Fats in Deproteinated Potato Wastewater with Different Carbon Sources

PubMed Central

Kieliszek, Marek; Jermacz, Karolina; Błażejak, Stanisław

2017-01-01

The search for efficient oleaginous microorganisms, which can be an alternative to fossil fuels and biofuels obtained from oilseed crops, has been going on for many years. The suitability of microorganisms in this regard is determined by their ability to biosynthesize lipids with preferred fatty acid profile along with the concurrent utilization of energy-rich industrial waste. In this study, we isolated, characterized, and identified kefir yeast strains using molecular biology techniques. The yeast isolates identified were Candida inconspicua, Debaryomyces hansenii, Kluyveromyces marxianus, Kazachstania unispora, and Zygotorulaspora florentina. We showed that deproteinated potato wastewater, a starch processing industry waste, supplemented with various carbon sources, including lactose and glycerol, is a suitable medium for the growth of yeast, which allows an accumulation of over 20% of lipid substances in its cells. Fatty acid composition primarily depended on the yeast strain and the carbon source used, and, based on our results, most of the strains met the criteria required for the production of biodiesel. In particular, this concerns a significant share of saturated fatty acids, such as C16:0 and C18:0, and unsaturated fatty acids, such as C18:1 and C18:2. The highest efficiency in lipid biosynthesis exceeded 6.3 g L−1. Kazachstania unispora was able to accumulate the high amount of palmitoleic acid. PMID:29098157

Identification and Characterization of Oleaginous Yeast Isolated from Kefir and Its Ability to Accumulate Intracellular Fats in Deproteinated Potato Wastewater with Different Carbon Sources.

PubMed

Gientka, Iwona; Kieliszek, Marek; Jermacz, Karolina; Błażejak, Stanisław

2017-01-01

The search for efficient oleaginous microorganisms, which can be an alternative to fossil fuels and biofuels obtained from oilseed crops, has been going on for many years. The suitability of microorganisms in this regard is determined by their ability to biosynthesize lipids with preferred fatty acid profile along with the concurrent utilization of energy-rich industrial waste. In this study, we isolated, characterized, and identified kefir yeast strains using molecular biology techniques. The yeast isolates identified were Candida inconspicua , Debaryomyces hansenii , Kluyveromyces marxianus , Kazachstania unispora , and Zygotorulaspora florentina . We showed that deproteinated potato wastewater, a starch processing industry waste, supplemented with various carbon sources, including lactose and glycerol, is a suitable medium for the growth of yeast, which allows an accumulation of over 20% of lipid substances in its cells. Fatty acid composition primarily depended on the yeast strain and the carbon source used, and, based on our results, most of the strains met the criteria required for the production of biodiesel. In particular, this concerns a significant share of saturated fatty acids, such as C16:0 and C18:0, and unsaturated fatty acids, such as C18:1 and C18:2. The highest efficiency in lipid biosynthesis exceeded 6.3 g L -1 . Kazachstania unispora was able to accumulate the high amount of palmitoleic acid.

Production of hydrogen driven from biomass waste to power Remote areas away from the electric grid utilizing fuel cells and internal combustion engines vehicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tawfik, Hazem

Recent concerns over the security and reliability of the world’s energy supply has caused a flux towards the research and development of renewable sources. A leading renewable source has been found in the biomass gasification of biological materials derived from organic matters such as wood chips, forest debris, and farm waste that are found in abundance in the USA. Accordingly, there is a very strong interest worldwide in the development of new technologies that provide an in-depth understanding of this economically viable energy source. This work aims to allow the coupling of biomass gasification and fuel cell systems as wellmore » as Internal Combustion Engines (ICE) to produce high-energy efficiency, clean environmental performance and near-zero greenhouse gas emissions. Biomass gasification is a process, which produces synthesis gas (syngas) that contains 19% hydrogen and 20% carbon monoxide from inexpensive organic matter waste. This project main goal is to provide cost effective energy to the public utilizing remote farms’ waste and landfill recycling area.« less

Developing a GIS for CO2 analysis using lightweight, open source components

NASA Astrophysics Data System (ADS)

Verma, R.; Goodale, C. E.; Hart, A. F.; Kulawik, S. S.; Law, E.; Osterman, G. B.; Braverman, A.; Nguyen, H. M.; Mattmann, C. A.; Crichton, D. J.; Eldering, A.; Castano, R.; Gunson, M. R.

2012-12-01

There are advantages to approaching the realm of geographic information systems (GIS) using lightweight, open source components in place of a more traditional web map service (WMS) solution. Rapid prototyping, schema-less data storage, the flexible interchange of components, and open source community support are just some of the benefits. In our effort to develop an application supporting the geospatial and temporal rendering of remote sensing carbon-dioxide (CO2) data for the CO2 Virtual Science Data Environment project, we have connected heterogeneous open source components together to form a GIS. Utilizing widely popular open source components including the schema-less database MongoDB, Leaflet interactive maps, the HighCharts JavaScript graphing library, and Python Bottle web-services, we have constructed a system for rapidly visualizing CO2 data with reduced up-front development costs. These components can be aggregated together, resulting in a configurable stack capable of replicating features provided by more standard GIS technologies. The approach we have taken is not meant to replace the more established GIS solutions, but to instead offer a rapid way to provide GIS features early in the development of an application and to offer a path towards utilizing more capable GIS technology in the future.

Carbon catabolite repression and cell dispersal affect degradation of the xenobiotic compound 3,4-dichloroaniline in Comamonas testosteroni WDL7 biofilms.

PubMed

Horemans, Benjamin; Breugelmans, Philip; Hofkens, Johan; Springael, Dirk

2017-03-01

Organic pollutant degrading biofilms in natural ecosystems and water treatment systems are often exposed to other carbon sources in addition to the pollutant. The availability of auxiliary carbon sources can lead to surplus biomass growth, changes in biofilm structure and carbon catabolite repression (CCR) which together will affect pollutant degradation rate and efficiency of the system. To understand the interplay between these processes, continuous biofilms of the 3,4-dichloroaniline (3,4-DCA) degrading Comamonas testosteroni WDL7-RFP were grown in single- and dual-substrate conditions with 3,4-DCA and/or citrate and reciprocal effects on 3,4-DCA/citrate degradation, biofilm biomass and biofilm structure were examined. The main mechanism affecting 3,4-DCA degradation in biofilms in dual-substrate conditions was citrate-mediated CCR as reflected by a decrease in specific 3,4-DCA degrading activity. Growth on citrate partially compensated for the lowered specific 3,4-DCA degradation activity under dual substrate conditions but not to the extent expected from growth observed under single-substrate conditions with citrate. This was explained by higher residual 3,4-DCA concentrations in the presence of citrate that increased cell dispersal in the biofilms. Our results show hampered pollutant removal in biofilms due to a complex interplay of auxiliary organic C source utilization for growth affecting the specific pollutant degradation rate and changes in cell physiology due to increased exposure to the pollutant as a result of lowered pollutant degradation rates. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Detection of Metabolism Function of Microbial Community of Corpses by Biolog-Eco Method.

PubMed

Jiang, X Y; Wang, J F; Zhu, G H; Ma, M Y; Lai, Y; Zhou, H

2016-06-01

To detect the changes of microbial community functional diversity of corpses with different postmortem interval （PMI） and to evaluate forensic application value for estimating PMI. The cultivation of microbial community from the anal swabs of a Sus scrofa and a human corpse placed in field environment from 0 to 240 h after death was performed using the Biolog-Eco Microplate and the variations of the absorbance values were also monitored. Combined with the technology of forensic pathology and flies succession, the metabolic characteristics and changes of microbial community on the decomposed corpse under natural environment were also observed. The diversity of microbial metabolism function was found to be negatively correlated with the number of maggots in the corpses. The freezing processing had the greatest impact on average well color development value at 0 h and the impact almost disappeared after 48 h. The diversity of microbial metabolism of the samples became relatively unstable after 192 h. The principal component analysis showed that 31 carbon sources could be consolidated for 5 principal components （accumulative contribution ratio >90%）.The carbon source tsquare-analysis showed that N -acetyl- D -glucosamine and L -serine were the dominant carbon sources for estimating the PMI （0=240 h） of the Sus scrofa and human corpse. The Biolog-Eco method can be used to reveal the metabolic differences of the carbon resources utilization of the microbial community on the corpses during 0-240 h after death, which could provide a new basis for estimating the PMI. Copyright© by the Editorial Department of Journal of Forensic Medicine

Toward Sustainable Amino Acid Production.

PubMed

Usuda, Yoshihiro; Hara, Yoshihiko; Kojima, Hiroyuki

Because the global amino acid production industry has been growing steadily and is expected to grow even more in the future, efficient production by fermentation is of great importance from economic and sustainability viewpoints. Many systems biology technologies, such as genome breeding, omics analysis, metabolic flux analysis, and metabolic simulation, have been employed for the improvement of amino acid-producing strains of bacteria. Synthetic biological approaches have recently been applied to strain development. It is also important to use sustainable carbon sources, such as glycerol or pyrolytic sugars from cellulosic biomass, instead of conventional carbon sources, such as glucose or sucrose, which can be used as food. Furthermore, reduction of sub-raw substrates has been shown to lead to reduction of environmental burdens and cost. Recently, a new fermentation system for glutamate production under acidic pH was developed to decrease the amount of one sub-raw material, ammonium, for maintenance of culture pH. At the same time, the utilization of fermentation coproducts, such as cells, ammonium sulfate, and fermentation broth, is a useful approach to decrease waste. In this chapter, further perspectives for future amino acid fermentation from one-carbon compounds are described.

Combining Observations in the Reflective Solar and Thermal Domains for Improved Mapping of Carbon, Water and Energy FLuxes

NASA Technical Reports Server (NTRS)

Houborg, Rasmus; Anderson, Martha; Kustas, Bill; Rodell, Matthew

2011-01-01

This study investigates the utility of integrating remotely sensed estimates of leaf chlorophyll (C(sub ab)) into a thermal-based Two-Source Energy Balance (TSEB) model that estimates land-surface CO2 and energy fluxes using an analytical, light-use-efficiency (LUE) based model of canopy resistance. Day to day variations in nominal LUE (LUE(sub n)) were assessed for a corn crop field in Maryland U.S.A. through model calibration with CO2 flux tower observations. The optimized daily LUE(sub n) values were then compared to estimates of C(sub ab) integrated from gridded maps of chlorophyll content weighted over the tower flux source area. Changes in Cab exhibited a curvilinear relationship with corresponding changes in daily calibrated LUE(sub n) values derived from the tower flux data, and hourly water, energy and carbon flux estimation accuracies from TSEB were significantly improved when using C(sub ab) for delineating spatio-temporal variations in LUE(sub n). The results demonstrate the synergy between thermal infrared and shortwave reflective wavebands in producing valuable remote sensing data for monitoring of carbon and water fluxes.

Agricultural Residues and Other Carbon-Based Resources as Feedstocks for Supercapacitor Electrodes

NASA Astrophysics Data System (ADS)

Wang, Yong

Agricultural residues are generally considered as renewable, economical and environmental-friendly sources to produce carbon-based nanomaterials with many advanced applications. Agricultural residues and by-products generated from the agricultural industry, such as distiller's dried grains with solubles (DDGS), are produced every year on a large scale but lack of proper utilization. As a result, seeking high-value applications based on agricultural residues is essential for the promotion of the economy in agricultural producing states like North Dakota, USA. With the fast development of nanotechnology in recent years, carbon-based nanomaterials have attracted intense research interests in the fields of chemistry, materials science and condensed matter physics due to many unique properties (e.g., chemical and thermal stability, electrical conductivity, mechanical strength, etc.). The development of low-cost nanomaterials using agricultural residues as feedstocks can be a promising route for the sustainable development of the agricultural industry. In this dissertation, the preparation of carbon-based materials from agricultural residues is explored. Many advanced applications are investigated, especially in the field of energy storage devices. The development of porous activate carbons were investigated in detail, and their application as electrode materials of supercapacitors was demonstrated. Hydrothermal carbonization of biomass to produce carbonaceous materials was also covered in this dissertation. In addition to traditional raw materials such as cellulose produced from wood industry, novel material sources such as bacterial cellulose were used to prepare nanocomposites that can be used for the electrodes of supercapacitors. This dissertation contributes to the sustainable development of the agricultural industry in North Dakota.

RNAi assisted genome evolution unveils yeast mutants with improved xylose utilization.

PubMed

HamediRad, Mohammad; Lian, Jiazhang; Li, Hejun; Zhao, Huimin

2018-06-01

Xylose is a major component of lignocellulosic biomass, one of the most abundant feedstocks for biofuel production. Therefore, efficient and rapid conversion of xylose to ethanol is crucial in the viability of lignocellulosic biofuel plants. In this study, RNAi Assisted Genome Evolution (RAGE) was used to improve the xylose utilization rate in SR8, one of the most efficient publicly available xylose utilizing Saccharomyces cerevisiae strains. To identify gene targets for further improvement, we created a genome-scale library consisting of both genetic over-expression and down-regulation mutations in SR8. Followed by screening in media containing xylose as the sole carbon source, yeast mutants with 29% faster xylose utilization, and 45% higher ethanol productivity were obtained relative to the parent strain. Two known and two new effector genes were identified in these mutant strains. Notably, down-regulation of CDC11, an essential gene, resulted in faster xylose utilization, and this gene target cannot be identified in genetic knock-out screens. © 2018 Wiley Periodicals, Inc.

Relationship between starch and lipid accumulation induced by nutrient depletion and replenishment in the microalga Parachlorella kessleri.

PubMed

Fernandes, Bruno; Teixeira, José; Dragone, Giuliano; Vicente, António A; Kawano, Shigeyuki; Bišová, Kateřina; Přibyl, Pavel; Zachleder, Vilém; Vítová, Milada

2013-09-01

Photosynthetic carbon partitioning into starch and neutral lipids, as well as the influence of nutrient depletion and replenishment on growth, pigments and storage compounds, were studied in the microalga, Parachlorella kessleri. Starch was utilized as a primary carbon and energy storage compound, but nutrient depletion drove the microalgae to channel fixed carbon into lipids as secondary storage compounds. Nutrient depletion inhibited both cellular division and growth and caused degradation of chlorophyll. Starch content decreased from an initial value of 25, to around 10% of dry weight (DW), while storage lipids increased from almost 0 to about 29% of DW. After transfer of cells into replenished mineral medium, growth, reproductive processes and chlorophyll content recovered within 2 days, while the content of both starch and lipids decreased markedly to 3 or less % of DW; this suggested that they were being used as a source of energy and carbon. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synthesizing and characterization of titanium diboride for composite bipolar plates in PEM fuel cell

NASA Astrophysics Data System (ADS)

Duddukuri, Ramesh

This research deals with the synthesis and characterization of titanium diboride (TiB2) from novel carbon coated precursors. This work provides information on using different boron sources and their effect on the resulting powders of TiB2. The process has two steps in which the oxide powders were first coated with carbon by cracking of a hydrocarbon gas, propylene (C3H6) and then, mixed with boron carbide and boric acid powders in a stoichiometric ratio. These precursors were treated at temperatures in the range of 1200--1400° C for 2 h in flowing Argon atmosphere to synthesize TiB2. The process utilizes a carbothermic reduction reaction of novel carbon coated precursor that has potential of producing high-quality powders (sub-micrometer and high purity). Single phase TiB2 powders produced, were compared with commercially available titanium diboride using X-ray diffraction and Transmission electron microscopy obtained from boron carbide and boric acid containing carbon coated precursor.

Photosynthetic carbon metabolism in Enteromorpha compressa (Chlorophyta)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beer, S.; Shragge, B.

1987-12-01

The intertidal macroalga Enteromorpha compressa showed the ability to use HCO/sub 3//sup -/, as an exogenous inorganic carbon (Ci) source for photosynthesis. However, although the natural sea water concentration of this carbon form was saturating, additional CO/sub 2/ above ambient Ci levels doubled net photosynthetic rates. Therefore, the productivity of this alga, when submerged, is likely to be limited by Ci. When plants were exposed to air, photosynthetic rates saturated at air-levels of CO/sub 2/ during mild desiccation. Based on carbon fixing enzyme activities and Ci pulse-chase incorporation patterns, it was found that Enteromorpha is a C/sub 3/ plant. However,more » this alga did not show O/sub 2/ inhibited photosynthetic rates at natural sea water Ci conditions. It is suggested that such a C/sub 4/-like gas exchange response is due to the HCO/sub 3//sup -/ utilization system concentrating CO/sub 2/ intracellularly, thus alleviating apparent photorespiration.« less

Phase-Change Aminopyridines as Carbon Dioxide Capture Solvents

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malhotra, Deepika; Page, Jordan P.; Bowden, Mark E.

Carbon dioxide is the main atmospheric greenhouse gas released from industrial point sources. In order to mitigate adverse environmental effects of these emissions, carbon capture, storage and utilization is required. To this end, several CO2 capture technologies are being developed for application in carbon capture, which include aqueous amines and water-lean solvents. Herein we report new aminopyridine solvents with the potential for CO2 capture from coal-fired power plants. These four solvents 2-picolylamine, 3-picolylamine, 4-picolylamine and N’-(pyridin-4-ylmethyl)ethane-1,2-diamine are liquids that rapidly bind CO2 to form crystalline solids at standard room temperature and pressure. These solvents have displayed high CO2 capture capacitymore » (11 - 20 wt%) and can be regenerated at temperatures in the range of 120 - 150 C. The advantage of these primary aminopyridine solvents is that crystalline salt product can be separated, making it possible to regenerate only the CO2-rich solid ultimately resulting in reduced energy penalty.« less

Evidence of a dynamic microbial community structure and predation through combined microbiological and stable isotope characterization

NASA Astrophysics Data System (ADS)

Druhan, J. L.; Bill, M.; Lim, H. C.; Wu, C.; Conrad, M. E.; Williams, K. H.; DePaolo, D. J.; Brodie, E.

2014-12-01

The speciation, reactivity and mobility of carbon in the near surface environment is intimately linked to the prevalence, diversity and dynamics of native microbial populations. We utilize this relationship by introducing 13C-labeled acetate to sediments recovered from a shallow aquifer system to track both the cycling of carbon through multiple redox pathways and the associated spatial and temporal evolution of bacterial communities in response to this nutrient source. Results demonstrate a net loss of sediment organic carbon over the course of the amendment experiment. Furthermore, these data demonstrated a source of isotopically labeled inorganic carbon that was not attributable to primary metabolism by acetate-oxidizing microorganisms. Fluid samples analyzed weekly for microbial composition by pyrosequencing of ribosomal RNA genes showed a transient microbial community structure, with distinct occurrences of Azoarcus, Geobacter and multiple sulfate reducing species over the course of the experiment. In combination with DNA sequencing data, the anomalous carbon cycling process is shown to occur exclusively during the period of predominant Geobacter species growth. Pyrosequencing indicated, and targeted cloning and sequencing confirmed the presence of several bacteriovorous protozoa, including species of the Breviata, Planococcus and Euplotes genera. Cloning and qPCR analysis demonstrated that Euplotes species were most abundant and displayed a growth trajectory that closely followed that of the Geobacter population. These results suggest a previously undocumented secondary turnover of biomass carbon related to protozoan grazing that was not sufficiently prevalent to be observed in bulk concentrations of carbon species in the system, but was clearly identifiable in the partitioning of carbon isotopes. The impact of predator-prey relationships on subsurface microbial community dynamics and therefore the flux of carbon through a system via the microbial biomass pool suggests a diversity of processes that should be considered for inclusion in reactive transport models that aim to predict carbon turnover, nutrient flux, and redox reactions in natural and stimulated subsurface systems.

Determination of microbial carbon sources and cycling during remediation of petroleum hydrocarbon impacted soil using natural abundance (14)C analysis of PLFA.

PubMed

Cowie, Benjamin R; Greenberg, Bruce M; Slater, Gregory F

2010-04-01

In a petroleum impacted land-farm soil in Sarnia, Ontario, compound-specific natural abundance radiocarbon analysis identified biodegradation by the soil microbial community as a major pathway for hydrocarbon removal in a novel remediation system. During remediation of contaminated soils by a plant growth promoting rhizobacteria enhanced phytoremediation system (PEPS), the measured Delta(14)C of phospholipid fatty acid (PLFA) biomarkers ranged from -793 per thousand to -897 per thousand, directly demonstrating microbial uptake and utilization of petroleum hydrocarbons (Delta(14)C(PHC) = -1000 per thousand). Isotopic mass balance indicated that more than 80% of microbial PLFA carbon was derived from petroleum hydrocarbons (PHC) and a maximum of 20% was obtained from metabolism of more modern carbon sources. These PLFA from the contaminated soils were the most (14)C-depleted biomarkers ever measured for an in situ environmental system, and this study demonstrated that the microbial community in this soil was subsisting primarily on petroleum hydrocarbons. In contrast, the microbial community in a nearby uncontaminated control soil maintained a more modern Delta(14)C signature than total organic carbon (Delta(14)C(PLFA) = +36 per thousand to -147 per thousand, Delta(14)C(TOC) = -148 per thousand), indicating preferential consumption of the most modern plant-derived fraction of soil organic carbon. Measurements of delta(13)C and Delta(14)C of soil CO(2) additionally demonstrated that mineralization of PHC contributed to soil CO(2) at the contaminated site. The CO(2) in the uncontaminated control soil exhibited substantially more modern Delta(14)C values, and lower soil CO(2) concentrations than the contaminated soils, suggesting increased rates of soil respiration in the contaminated soils. In combination, these results demonstrated that biodegradation in the soil microbial community was a primary pathway of petroleum hydrocarbon removal in the PEPS system. This study highlights the power of natural abundance radiocarbon for determining microbial carbon sources and identifying biodegradation pathways in complex remediation systems.

Quantitative iTRAQ-based secretome analysis reveals species-specific and temporal shifts in carbon utilization strategies among manganese(II)-oxidizing Ascomycete fungi

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zeiner, Carolyn A.; Purvine, Samuel O.; Zink, Erika M.

Fungi generate a wide range of extracellular hydrolytic and oxidative enzymes and reactive metabolites, collectively known as the secretome, that synergistically drive plant litter decomposition in the environment. While secretome studies of model organisms have greatly expanded our knowledge of these enzymes, few have extended secretome characterization to environmental isolates, particularly filamentous Ascomycetes, or directly compared temporal patterns of enzyme utilization among diverse species. Thus, the mechanisms of carbon (C) degradation by many ubiquitous soil fungi remain poorly understood. Here in this study we use a combination of iTRAQ proteomics and extracellular enzyme activity assays to compare the protein compositionmore » of the secretomes of four manganese(II)-oxidizing Ascomycete fungi over a three-week time course. We demonstrate that the fungi exhibit striking differences in the regulation of extracellular lignocellulose-degrading enzymes among species and over time, revealing species-specific and temporal shifts in C utilization strategies as they degrade the same substrate. Specifically, our findings suggest that Alternaria alternata SRC1lrK2f and Paraconiothyrium sporulosum AP3s5-JAC2a employ sequential enzyme secretion patterns concomitant with decreasing resource availability. Stagonospora sp. SRC1lsM3a preferentially degrades proteinaceous substrate before switching to carbohydrates, and Pyrenochaeta sp. DS3sAY3a utilizes primarily peptidases to aggressively attack carbon sources in a concentrated burst. In conclusion, this work highlights the diversity of operative metabolic strategies among understudied yet ubiquitous cellulose-degrading Ascomycetes, enhancing our understanding of their contribution to C turnover in the environment.« less

Quantitative iTRAQ-based secretome analysis reveals species-specific and temporal shifts in carbon utilization strategies among manganese(II)-oxidizing Ascomycete fungi

DOE PAGES

Zeiner, Carolyn A.; Purvine, Samuel O.; Zink, Erika M.; ...

2017-07-01

Fungi generate a wide range of extracellular hydrolytic and oxidative enzymes and reactive metabolites, collectively known as the secretome, that synergistically drive plant litter decomposition in the environment. While secretome studies of model organisms have greatly expanded our knowledge of these enzymes, few have extended secretome characterization to environmental isolates, particularly filamentous Ascomycetes, or directly compared temporal patterns of enzyme utilization among diverse species. Thus, the mechanisms of carbon (C) degradation by many ubiquitous soil fungi remain poorly understood. Here in this study we use a combination of iTRAQ proteomics and extracellular enzyme activity assays to compare the protein compositionmore » of the secretomes of four manganese(II)-oxidizing Ascomycete fungi over a three-week time course. We demonstrate that the fungi exhibit striking differences in the regulation of extracellular lignocellulose-degrading enzymes among species and over time, revealing species-specific and temporal shifts in C utilization strategies as they degrade the same substrate. Specifically, our findings suggest that Alternaria alternata SRC1lrK2f and Paraconiothyrium sporulosum AP3s5-JAC2a employ sequential enzyme secretion patterns concomitant with decreasing resource availability. Stagonospora sp. SRC1lsM3a preferentially degrades proteinaceous substrate before switching to carbohydrates, and Pyrenochaeta sp. DS3sAY3a utilizes primarily peptidases to aggressively attack carbon sources in a concentrated burst. In conclusion, this work highlights the diversity of operative metabolic strategies among understudied yet ubiquitous cellulose-degrading Ascomycetes, enhancing our understanding of their contribution to C turnover in the environment.« less

The Vulcan Project: Recent advances and emissions estimation for the NACP mid-continent intensive campaign region

NASA Astrophysics Data System (ADS)

Gurney, K. R.; Zhou, Y.; Geethakumar, S.; Godbole, A.; Mendoza, D. L.; Vaidhyanathan, M.; Sahni, N.

2009-12-01

The Vulcan Project has quantified 2002 fossil fuel CO2 for the US at the sub-county/hourly scale and is a key component of attributing CO2 fluxes within the North American Carbon Program. Vulcan approached quantification of CO2 emissions by leveraging information already contained within regulatory and monitoring agencies including the US EPA’s Acid Rain Program, the EPA’s National Emissions Inventory for the assessment of nationally regulated air pollution, the Department of Energy, the U.S. Census and the Department of Transportation. By utilizing the inventory emissions of carbon monoxide combined with fuel/device-specific emission factors, we have calculated CO2 emissions for industrial point sources, power plants, mobile sources, residential and commercial sectors with information on fuel used and source classification information. In this presentation, I provide critical recent advances in the Vulcan Project with particular emphasis on our contribution to the NACP mid-continent intensive campaign. Version 1.2 of the Vulcan fossil fuel CO2 emissions inventory includes the 2008 US Census road atlas, overcoming many of the missing roads and links that were prevalent in previous road atlas releases. This offers better spatial allocation of the onroad emissions. Figure 1 shows the improved road layer density for the MCI study region. Furthermore the temporal dimension of onroad emissions have been improved through the use of hourly traffic monitoring data at roughly 6000 monitoring locations across the US. The residential and commercial sector emissions now have hourly time structure via a spatially explicit heating degree day calculation utilizing the North American Regional Reanalysis temperature output. Finally, we have generated a multiyear (1997-2008) data product for the MCI region through use of Energy Information Administration state-level fuel sales data. Figure 1. improved road density via utilization of the new 2008 US census road layer. Left: previous Vulcan release road density; Right: latest Vulcan release road density

An Ocean Acidification Acclimatised Green Tide Alga Is Robust to Changes of Seawater Carbon Chemistry but Vulnerable to Light Stress

PubMed Central

Li, Xinshu; Feng, Zhihua; Xu, Juntian

2016-01-01

Ulva is the dominant genus in the green tide events and is considered to have efficient CO2 concentrating mechanisms (CCMs). However, little is understood regarding the impacts of ocean acidification on the CCMs of Ulva and the consequences of thalli’s acclimation to ocean acidification in terms of responding to environmental factors. Here, we grew a cosmopolitan green alga, Ulva linza at ambient (LC) and elevated (HC) CO2 levels and investigated the alteration of CCMs in U. linza grown at HC and its responses to the changed seawater carbon chemistry and light intensity. The inhibitors experiment for photosynthetic inorganic carbon utilization demonstrated that acidic compartments, extracellular carbonic anhydrase (CA) and intracellular CA worked together in the thalli grown at LC and the acquisition of exogenous carbon source in the thalli could be attributed to the collaboration of acidic compartments and extracellular CA. Contrastingly, when U. linza was grown at HC, extracellular CA was completely inhibited, acidic compartments and intracellular CA were also down-regulated to different extents and thus the acquisition of exogenous carbon source solely relied on acidic compartments. The down-regulated CCMs in U. linza did not affect its responses to changes of seawater carbon chemistry but led to a decrease of net photosynthetic rate when thalli were exposed to increased light intensity. This decrease could be attributed to photodamage caused by the combination of the saved energy due to the down-regulated CCMs and high light intensity. Our findings suggest future ocean acidification might impose depressing effects on green tide events when combined with increased light exposure. PMID:28033367

An Ocean Acidification Acclimatised Green Tide Alga Is Robust to Changes of Seawater Carbon Chemistry but Vulnerable to Light Stress.

PubMed

Gao, Guang; Liu, Yameng; Li, Xinshu; Feng, Zhihua; Xu, Juntian

2016-01-01

Ulva is the dominant genus in the green tide events and is considered to have efficient CO2 concentrating mechanisms (CCMs). However, little is understood regarding the impacts of ocean acidification on the CCMs of Ulva and the consequences of thalli's acclimation to ocean acidification in terms of responding to environmental factors. Here, we grew a cosmopolitan green alga, Ulva linza at ambient (LC) and elevated (HC) CO2 levels and investigated the alteration of CCMs in U. linza grown at HC and its responses to the changed seawater carbon chemistry and light intensity. The inhibitors experiment for photosynthetic inorganic carbon utilization demonstrated that acidic compartments, extracellular carbonic anhydrase (CA) and intracellular CA worked together in the thalli grown at LC and the acquisition of exogenous carbon source in the thalli could be attributed to the collaboration of acidic compartments and extracellular CA. Contrastingly, when U. linza was grown at HC, extracellular CA was completely inhibited, acidic compartments and intracellular CA were also down-regulated to different extents and thus the acquisition of exogenous carbon source solely relied on acidic compartments. The down-regulated CCMs in U. linza did not affect its responses to changes of seawater carbon chemistry but led to a decrease of net photosynthetic rate when thalli were exposed to increased light intensity. This decrease could be attributed to photodamage caused by the combination of the saved energy due to the down-regulated CCMs and high light intensity. Our findings suggest future ocean acidification might impose depressing effects on green tide events when combined with increased light exposure.

Status of ion sources at National Institute of Radiological Sciences.

PubMed

Kitagawa, A; Fujita, T; Goto, A; Hattori, T; Hamano, T; Hojo, S; Honma, T; Imaseki, H; Katagiri, K; Muramatsu, M; Sakamoto, Y; Sekiguchi, M; Suda, M; Sugiura, A; Suya, N

2012-02-01

The National Institute of Radiological Sciences (NIRS) maintains various ion accelerators in order to study the effects of radiation of the human body and medical uses of radiation. Two electrostatic tandem accelerators and three cyclotrons delivered by commercial companies have offered various life science tools; these include proton-induced x-ray emission analysis (PIXE), micro beam irradiation, neutron exposure, and radioisotope tracers and probes. A duoplasmatron, a multicusp ion source, a penning ion source (PIG), and an electron cyclotron resonance ion source (ECRIS) are in operation for these purposes. The Heavy-Ion Medical Accelerator in Chiba (HIMAC) is an accelerator complex for heavy-ion radiotherapy, fully developed by NIRS. HIMAC is utilized not only for daily treatment with the carbon beam but also for fundamental experiments. Several ECRISs and a PIG at HIMAC satisfy various research and clinical requirements.

Status of ion sources at National Institute of Radiological Sciencesa)

NASA Astrophysics Data System (ADS)

Kitagawa, A.; Fujita, T.; Goto, A.; Hattori, T.; Hamano, T.; Hojo, S.; Honma, T.; Imaseki, H.; Katagiri, K.; Muramatsu, M.; Sakamoto, Y.; Sekiguchi, M.; Suda, M.; Sugiura, A.; Suya, N.

2012-02-01

The National Institute of Radiological Sciences (NIRS) maintains various ion accelerators in order to study the effects of radiation of the human body and medical uses of radiation. Two electrostatic tandem accelerators and three cyclotrons delivered by commercial companies have offered various life science tools; these include proton-induced x-ray emission analysis (PIXE), micro beam irradiation, neutron exposure, and radioisotope tracers and probes. A duoplasmatron, a multicusp ion source, a penning ion source (PIG), and an electron cyclotron resonance ion source (ECRIS) are in operation for these purposes. The Heavy-Ion Medical Accelerator in Chiba (HIMAC) is an accelerator complex for heavy-ion radiotherapy, fully developed by NIRS. HIMAC is utilized not only for daily treatment with the carbon beam but also for fundamental experiments. Several ECRISs and a PIG at HIMAC satisfy various research and clinical requirements.

Reading the Tea Leaves: How Utilities in the West Are Managing Carbon Regulatory Risk in their Resource Plans

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbose, Galen; Wiser, Ryan; Phadke, Amol

2008-02-01

The long economic lifetime and development lead-time of many electric infrastructure investments requires that utility resource planning consider potential costs and risks over a lengthy time horizon. One long-term -- and potentially far-reaching -- risk currently facing the electricity industry is the uncertain cost of future carbon dioxide (CO2) regulations. Recognizing the importance of this issue, many utilities (sometimes spurred by state regulatory requirements) are beginning to actively assess carbon regulatory risk within their resource planning processes, and to evaluate options for mitigating that risk. However, given the relatively recent emergence of this issue and the rapidly changing political landscape,more » methods and assumptions used to analyze carbon regulatory risk, and the impact of this analysis on the selection of a preferred resource portfolio, vary considerably across utilities. In this study, we examine the treatment of carbon regulatory risk in utility resource planning, through a comparison of the most-recent resource plans filed by fifteen investor-owned and publicly-owned utilities in the Western U.S. Together, these utilities account for approximately 60percent of retail electricity sales in the West, and cover nine of eleven Western states. This report has two related elements. First, we compare and assess utilities' approaches to addressing key analytical issues that arise when considering the risk of future carbon regulations. Second, we summarize the composition and carbon intensity of the preferred resource portfolios selected by these fifteen utilities and compare them to potential CO2 emission benchmark levels.« less

Designing overall stoichiometric conversions and intervening metabolic reactions

DOE PAGES

Chowdhury, Anupam; Maranas, Costas D.

2015-11-04

Existing computational tools for de novo metabolic pathway assembly, either based on mixed integer linear programming techniques or graph-search applications, generally only find linear pathways connecting the source to the target metabolite. The overall stoichiometry of conversion along with alternate co-reactant (or co-product) combinations is not part of the pathway design. Therefore, global carbon and energy efficiency is in essence fixed with no opportunities to identify more efficient routes for recycling carbon flux closer to the thermodynamic limit. Here, we introduce a two-stage computational procedure that both identifies the optimum overall stoichiometry (i.e., optStoic) and selects for (non-)native reactions (i.e.,more » minRxn/minFlux) that maximize carbon, energy or price efficiency while satisfying thermodynamic feasibility requirements. Implementation for recent pathway design studies identified non-intuitive designs with improved efficiencies. Specifically, multiple alternatives for non-oxidative glycolysis are generated and non-intuitive ways of co-utilizing carbon dioxide with methanol are revealed for the production of C 2+ metabolites with higher carbon efficiency.« less

Glassy carbon/multi walled carbon nanotube/cadmium sulphide photoanode for light energy storage in vanadium photoelectrochemical cell

NASA Astrophysics Data System (ADS)

Peimanifard, Zahra; Rashid-Nadimi, Sahar

2015-12-01

The aim of this study is utilizing the artificial photosynthesis, which is an attractive and challenging theme in the photoelectrocatalytic water splitting, to charge the vanadium redox flow battery (VRFB). In this work multi walled carbon nanotube/cadmium sulphide hybrid is employed as a photoanode material to oxidize VO2+ toVO2+ for charging the positive vanadium redox flow battery's half-cell. Characterization studies are also described using the scanning electron microscopic-energy-dispersive X-ray spectroscopy (SEM-EDS), inductively coupled plasma atomic emission spectroscopy (ICP-AES) and UV-Visible methods. The phtoelectrochemical performance is characterized by cyclic voltammetry and chronoamperometry. Applied bias photon-to-current efficiency (ABPE) is achieved for both two and three-electrode configurations. The glassy carbon/multi walled carbon nanotube/cadmium sulphide yields high maximum ABPE of 2.6% and 2.12% in three and two-electrode setups, respectively. These results provide a useful guideline in designing photoelectrochemical cells for charging the vanadium redox flow batteries by sunlight as a low cost, free and abundant energy source, which does not rely on an external power input.

Rebar Graphene

PubMed Central

2015-01-01

As the cylindrical sp2-bonded carbon allotrope, carbon nanotubes (CNTs) have been widely used to reinforce bulk materials such as polymers, ceramics, and metals. However, both the concept demonstration and the fundamental understanding on how 1D CNTs reinforce atomically thin 2D layered materials, such as graphene, are still absent. Here, we demonstrate the successful synthesis of CNT-toughened graphene by simply annealing functionalized CNTs on Cu foils without needing to introduce extraneous carbon sources. The CNTs act as reinforcing bar (rebar), toughening the graphene through both π–π stacking domains and covalent bonding where the CNTs partially unzip and form a seamless 2D conjoined hybrid as revealed by aberration-corrected scanning transmission electron microscopy analysis. This is termed rebar graphene. Rebar graphene can be free-standing on water and transferred onto target substrates without needing a polymer-coating due to the rebar effects of the CNTs. The utility of rebar graphene sheets as flexible all-carbon transparent electrodes is demonstrated. The in-plane marriage of 1D nanotubes and 2D layered materials might herald an electrical and mechanical union that extends beyond carbon chemistry. PMID:24694285

Bacterial Utilization of Ether Glycols

PubMed Central

Fincher, Edward L.; Payne, W. J.

1962-01-01

A soil bacterium capable of using oligo- and polyethylene glycols and ether alcohols as sole sources of carbon for aerobic growth was isolated. The effects of substituent groups added to the ether bonds on the acceptability of the compounds as substrates were studied. Mechanisms for the incorporation of two-carbon compounds were demonstrated by the observation that acetate, glyoxylate, ethylene glycol, and a number of the tricarboxylic acid cycle intermediates served as growth substrates in minimal media. The rate of oxidation of the short-chained ethylene glycols by adapted resting cells varied directly with increasing numbers of two-carbon units in the chains from one to four. The amount of oxygen consumed per carbon atom of oligo- and polyethylene glycols was 100% of theoretical, but only 67% of theoretical for ethylene glycol. Resting cells oxidized oligo- and polyethylene glycols with 2 to 600 two-carbon units in the chains. Longer chained polyethylene glycols (up to 6,000) were oxidized at a very slow rate by these cells. Dehydrogenation of triethylene glycol by adapted cells was observed, coupling the reaction with methylene blue reduction. PMID:13945208

A hierarchically honeycomb-like carbon via one-step surface and pore adjustment with superior capacity for lithium-oxygen batteries

NASA Astrophysics Data System (ADS)

Li, Jing; Zhang, Yining; Zhou, Wei; Nie, Hongjiao; Zhang, Huamin

2014-09-01

Li-O2 batteries have attracted considerable attention due to their high energy density. The critical challenges that limit the practical applications include effective utilization of electrode space for solid products deposition and acceptable cycling performance. In the present work, a nitrogen-doped micron-sized honeycomb-like carbon is developed for use as a cathode material for Li-O2 batteries. This novel material is obtained by using nano-CaCO3 particles as hard template and sucrose as the carbon source, followed by thermal annealing at 800 °C in ammonia. With one-step ammonia activation, surface nitrogenation and further pore structure optimization are realized simultaneously. The material exhibits enhanced activity for oxygen reduction reaction and oxygen transfer ability. Surprisingly, an improved cycling stability is also obtained. As a result, a superior discharge capacity up to 12,600 mAh g-1 is achieved, about 4 times that of commercial Ketjenblack carbon. The results provide a novel route to construct effective non-metal carbon-based cathodes for high performance of Li-O2 batteries.

Utilization of the gypsum from a wet limestone flue gas desulfurization process

USGS Publications Warehouse

Chou, I.-Ming; Patel, V.; Lytle, J.M.; Chou, S.J.; Carty, R.H.

1999-01-01

The authors have been developing a process which converts FGD-gypsum to ammonium sulfate fertilizer with precipitated calcium carbonate as a by-product during the conversion. Preliminary cost estimates suggest that the process is economically feasible when ammonium sulfate crystals are produced in a granular size (1.2 to 3.3 mm), instead of a powder form. However, if additional revenue from the sale of the PCC for higher-value commercial application is applicable, this could further improve the economics of the process. Ammonium sulfate is known to be an excellent source of nitrogen and sulfur in fertilizer for corn and wheat production. It was not known what impurities might co-exist in ammonium sulfate derived from scrubber gypsum. Before the product could be recommended for use on farm land, the impurities and their impact on soil productivity had to be assessed. The objectives of this phase of the study were to evaluate the chemical properties of ammonium sulfate made from the FGD-gypsum, to estimate its effects on soil productivity, and to survey the marketability of the two products. The results of this phase of the study indicated that the impurities in the ammonium sulfate produced would not impose any practical limitations on its use at application levels used by farmers. The market survey showed that the sale price of solid ammonium sulfate fertilizer increased significantly from 1974 at $110/ton to 1998 at $187/ton. Utilities currently pay $16 to $20/ton for the calcium carbonate they use in their flue gas scrubber system. The industries making animal-feed grade calcium supplement pay $30/ton to $67/m-ton for their source of calcium carbonate. Paper, paint, and plastic industries pay as much as $200 to $300/ton for their calcium carbonate filers. The increased sale price of solid ammonium sulfate fertilizer and the possible additional revenue from the sale of the PCC by-product could further improve the economics of producing ammonium sulfate from FGD-gypsum.

Proteomic analysis of carbon concentrating chemolithotrophic bacteria Serratia sp. for sequestration of carbon dioxide.

PubMed

Bharti, Randhir K; Srivastava, Shaili; Thakur, Indu Shekhar

2014-01-01

A chemolithotrophic bacterium enriched in the chemostat in presence of sodium bicarbonate as sole carbon source was identified as Serratia sp. by 16S rRNA sequencing. Carbon dioxide sequestering capacity of bacterium was detected by carbonic anhydrase enzyme and ribulose-1, 5- bisphosphate carboxylase/oxygenase (RuBisCO). The purified carbonic anhydrase showed molecular weight of 29 kDa. Molecular weight of RuBisCO was 550 kDa as determined by fast protein liquid chromatography (FPLC), however, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed presence of two subunits whose molecular weights were 56 and 14 kDa. The Western blot analysis of the crude protein and purified sample cross reacted with RuBisCO large-subunit polypeptides antibodies showed strong band pattern at molecular weight around 56 kDa regions. Whole cell soluble proteins of Serratia sp. grown under autotrophic and heterotrophic conditions were resolved by two-dimensional gel electrophoresis and MALDI-TOF/MS for differential expression of proteins. In proteomic analysis of 63 protein spots, 48 spots were significantly up-regulated in the autotrophically grown cells; seven enzymes showed its utilization in autotrophic carbon fixation pathways and other metabolic activities of bacterium including lipid metabolisms indicated sequestration potency of carbon dioxide and production of biomaterials.

Proteomic Analysis of Carbon Concentrating Chemolithotrophic Bacteria Serratia sp. for Sequestration of Carbon Dioxide

PubMed Central

Bharti, Randhir K.; Srivastava, Shaili; Thakur, Indu Shekhar

2014-01-01

A chemolithotrophic bacterium enriched in the chemostat in presence of sodium bicarbonate as sole carbon source was identified as Serratia sp. by 16S rRNA sequencing. Carbon dioxide sequestering capacity of bacterium was detected by carbonic anhydrase enzyme and ribulose-1, 5- bisphosphate carboxylase/oxygenase (RuBisCO). The purified carbonic anhydrase showed molecular weight of 29 kDa. Molecular weight of RuBisCO was 550 kDa as determined by fast protein liquid chromatography (FPLC), however, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed presence of two subunits whose molecular weights were 56 and 14 kDa. The Western blot analysis of the crude protein and purified sample cross reacted with RuBisCO large-subunit polypeptides antibodies showed strong band pattern at molecular weight around 56 kDa regions. Whole cell soluble proteins of Serratia sp. grown under autotrophic and heterotrophic conditions were resolved by two-dimensional gel electrophoresis and MALDI-TOF/MS for differential expression of proteins. In proteomic analysis of 63 protein spots, 48 spots were significantly up-regulated in the autotrophically grown cells; seven enzymes showed its utilization in autotrophic carbon fixation pathways and other metabolic activities of bacterium including lipid metabolisms indicated sequestration potency of carbon dioxide and production of biomaterials. PMID:24619032

Identifying Aerosol Type/Mixture from Aerosol Absorption Properties Using AERONET

NASA Technical Reports Server (NTRS)

Giles, D. M.; Holben, B. N.; Eck, T. F.; Sinyuk, A.; Dickerson, R. R.; Thompson, A. M.; Slutsker, I.; Li, Z.; Tripathi, S. N.; Singh, R. P.;

Modeling Atmospheric CO2 Processes to Constrain the Missing Sink

NASA Technical Reports Server (NTRS)

Kawa, S. R.; Denning, A. S.; Erickson, D. J.; Collatz, J. C.; Pawson, S.

2005-01-01

We report on a NASA supported modeling effort to reduce uncertainty in carbon cycle processes that create the so-called missing sink of atmospheric CO2. Our overall objective is to improve characterization of CO2 source/sink processes globally with improved formulations for atmospheric transport, terrestrial uptake and release, biomass and fossil fuel burning, and observational data analysis. The motivation for this study follows from the perspective that progress in determining CO2 sources and sinks beyond the current state of the art will rely on utilization of more extensive and intensive CO2 and related observations including those from satellite remote sensing. The major components of this effort are: 1) Continued development of the chemistry and transport model using analyzed meteorological fields from the Goddard Global Modeling and Assimilation Office, with comparison to real time data in both forward and inverse modes; 2) An advanced biosphere model, constrained by remote sensing data, coupled to the global transport model to produce distributions of CO2 fluxes and concentrations that are consistent with actual meteorological variability; 3) Improved remote sensing estimates for biomass burning emission fluxes to better characterize interannual variability in the atmospheric CO2 budget and to better constrain the land use change source; 4) Evaluating the impact of temporally resolved fossil fuel emission distributions on atmospheric CO2 gradients and variability. 5) Testing the impact of existing and planned remote sensing data sources (e.g., AIRS, MODIS, OCO) on inference of CO2 sources and sinks, and use the model to help establish measurement requirements for future remote sensing instruments. The results will help to prepare for the use of OCO and other satellite data in a multi-disciplinary carbon data assimilation system for analysis and prediction of carbon cycle changes and carbodclimate interactions.

Evaluation of Ten Wild Nigerian Mushrooms for Amylase and Cellulase Activities

PubMed Central

Adeoyo, Olusegun Richard

2011-01-01

Amylases and cellulases are important enzymes that can be utilized for various biological activities. Ten different wild Nigerian mushrooms (Agaricus blazei, Agaricus sp., Corilopsis occidentalis, Coriolus versicolor, Termitomyces clypeatus, Termitomyces globulus, Pleurotus tuber-regium, Podoscypha bolleana, Pogonomyces hydnoides, and Nothopanus hygrophanus) were assayed for production of these secondary metabolites. The results revealed that most of the tested wild fungi demonstrated very good amylase and cellulase activities. With the incorporation of carboxymethyl-cellulose (a carbon source) into the culture medium, Agaricus blazei had the highest amylolytic activity of 0.60 unit/mL (at 25℃, pH 6.8). This was followed in order by P. tuber-regium and Agaricus sp. with 0.42 and 0.39 unit/mL, respectively (p ≤ 0.05). Maltose and sucrose supplementation into the submerged liquid medium made N. hygrophanus and P. hydnoides to exhibit very low amylase activities of 0.09 and 0.11 unit/mL, respectively. Introducing peptone (an organic nitrogen source) into the basal medium enhanced the ability of C. versicolor to produce a cellulase value of 0.74 unit/mL. Other organic nitrogen sources that supported good cellulase activities were yeast extract and urea. Sodium nitrate (inorganic nitrogen source) generally inhibited cellulase production in all mushrooms. The best carbon source was carboxymethyl-cellulose, which promoted very high cellulase activity of 0.67 unit/mL in C. versicolor, which was followed in order by P. tuber-regium, T. chypeatus, and C. occidentalis (p ≤ 0.05). Sucrose was the poorest carbon compound, supporting the lowest values of 0.01, 0.01, and 0.14 unit/mL in P. hydnoides, A. blazei, and Agaricus sp., respectively. PMID:22783085

Biodegradation of cypermethrin by Micrococcus sp. strain CPN 1.

PubMed

Tallur, Preeti N; Megadi, Veena B; Ninnekar, Harichandra Z

2008-02-01

A bacterium capable of utilizing pyrethroid pesticide cypermethrin as sole source of carbon was isolated from soil and identified as a Micrococcus sp. The organism also utilized fenvalerate, deltamethrin, perimethrin, 3-phenoxybenzoate, phenol, protocatechuate and catechol as growth substrates. The organism degraded cypermethrin by hydrolysis of ester linkage to yield 3-phenoxybenzoate, leading to loss of its insecticidal activity. 3-Phenoxybenzoate was further metabolized by diphenyl ether cleavage to yield protocatechuate and phenol as evidenced by isolation and identification of metabolites and enzyme activities in the cell-free extracts. Protocatechuate and phenol were oxidized by ortho-cleavage pathway. Thus, the organism was versatile in detoxification and complete mineralization of pyrethroid cypermethrin.

A common bacterial metabolite elicits prion-based bypass of glucose repression

PubMed Central

Garcia, David M; Dietrich, David; Clardy, Jon; Jarosz, Daniel F

2016-01-01

Robust preference for fermentative glucose metabolism has motivated domestication of the budding yeast Saccharomyces cerevisiae. This program can be circumvented by a protein-based genetic element, the [GAR+] prion, permitting simultaneous metabolism of glucose and other carbon sources. Diverse bacteria can elicit yeast cells to acquire [GAR+], although the molecular details of this interaction remain unknown. Here we identify the common bacterial metabolite lactic acid as a strong [GAR+] inducer. Transient exposure to lactic acid caused yeast cells to heritably circumvent glucose repression. This trait had the defining genetic properties of [GAR+], and did not require utilization of lactic acid as a carbon source. Lactic acid also induced [GAR+]-like epigenetic states in fungi that diverged from S. cerevisiae ~200 million years ago, and in which glucose repression evolved independently. To our knowledge, this is the first study to uncover a bacterial metabolite with the capacity to potently induce a prion. DOI: http://dx.doi.org/10.7554/eLife.17978.001 PMID:27906649

The genome and phenome of the green alga Chloroidium sp. UTEX 3007 reveal adaptive traits for desert acclimatization

PubMed Central

Nelson, David R; Khraiwesh, Basel; Fu, Weiqi; Alseekh, Saleh; Jaiswal, Ashish; Chaiboonchoe, Amphun; Hazzouri, Khaled M; O’Connor, Matthew J; Butterfoss, Glenn L; Drou, Nizar; Rowe, Jillian D; Harb, Jamil; Fernie, Alisdair R; Gunsalus, Kristin C; Salehi-Ashtiani, Kourosh

2017-01-01

To investigate the phenomic and genomic traits that allow green algae to survive in deserts, we characterized a ubiquitous species, Chloroidium sp. UTEX 3007, which we isolated from multiple locations in the United Arab Emirates (UAE). Metabolomic analyses of Chloroidium sp. UTEX 3007 indicated that the alga accumulates a broad range of carbon sources, including several desiccation tolerance-promoting sugars and unusually large stores of palmitate. Growth assays revealed capacities to grow in salinities from zero to 60 g/L and to grow heterotrophically on >40 distinct carbon sources. Assembly and annotation of genomic reads yielded a 52.5 Mbp genome with 8153 functionally annotated genes. Comparison with other sequenced green algae revealed unique protein families involved in osmotic stress tolerance and saccharide metabolism that support phenomic studies. Our results reveal the robust and flexible biology utilized by a green alga to successfully inhabit a desert coastline. DOI: http://dx.doi.org/10.7554/eLife.25783.001 PMID:28623667

Synthesis and biological evaluation of aryl-oxadiazoles as inhibitors of Mycobacterium tuberculosis.

PubMed

Martinez-Grau, Maria Angeles; Valcarcel, Isabel C Gonzalez; Early, Julie V; Gessner, Richard Klaus; de Melo, Candice Soares; de la Nava, Eva Maria Martin; Korkegian, Aaron; Ovechkina, Yulia; Flint, Lindsay; Gravelle, Anisa; Cramer, Jeff W; Desai, Prashant V; Street, Leslie J; Odingo, Joshua; Masquelin, Thierry; Chibale, Kelly; Parish, Tanya

2018-06-01

Despite increased research efforts to find new treatments for tuberculosis in recent decades, compounds with novel mechanisms of action are still required. We previously identified a series of novel aryl-oxadiazoles with anti-tubercular activity specific for bacteria using butyrate as a carbon source. We explored the structure activity relationship of this series. Structural modifications were performed in all domains to improve potency and physico-chemical properties. A number of compounds displayed sub-micromolar activity against M. tuberculosis utilizing butyrate, but not glucose as the carbon source. Compounds showed no or low cytotoxicity against eukaryotic cells. Three compounds were profiled in mouse pharmacokinetic studies. Plasma clearance was low to moderate but oral exposure suggested solubility-limited drug absorption in addition to first pass metabolism. The presence of a basic nitrogen in the linker slightly increased solubility, and salt formation optimized aqueous solubility. Our findings suggest that the 1,3,4-oxadiazoles are useful tools and warrant further investigation. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Production and characterization of rhamnolipid using palm oil agricultural refinery waste.

PubMed

Radzuan, Mohd Nazren; Banat, Ibrahim M; Winterburn, James

2017-02-01

In this research we assess the feasibility of using palm oil agricultural refinery waste as a carbon source for the production of rhamnolipid biosurfactant through fermentation. The production and characterization of rhamnolipid produced by Pseudomonas aeruginosa PAO1 grown on palm fatty acid distillate (PFAD) under batch fermentation were investigated. Results show that P. aeruginosa PAO1 can grow and produce 0.43gL -1 of rhamnolipid using PFAD as the sole carbon source. Identification of the biosurfactant product using mass spectrometry confirmed the presence of monorhamnolipid and dirhamnolipid. The rhamnolipid produced from PFAD were able to reduce surface tension to 29mNm -1 with a critical micelle concentration (CMC) 420mgL -1 and emulsify kerosene and sunflower oil, with an emulsion index up to 30%. Results demonstrate that PFAD could be used as a low-cost substrate for rhamnolipid production, utilizing and transforming it into a value added biosurfactant product. Copyright © 2016 Elsevier Ltd. All rights reserved.

Engineering xylose metabolism for production of polyhydroxybutyrate in the non-model bacterium Burkholderia sacchari.

PubMed

Guamán, Linda P; Barba-Ostria, Carlos; Zhang, Fuzhong; Oliveira-Filho, Edmar R; Gomez, José Gregório C; Silva, Luiziana F

2018-05-15

Despite its ability to grow and produce high-value molecules using renewable carbon sources, two main factors must be improved to use Burkholderia sacchari as a chassis for bioproduction at an industrial scale: first, the lack of molecular tools to engineer this organism and second, the inherently slow growth rate and poly-3-hydroxybutyrate [P(3HB)] production using xylose. In this work, we have addressed both factors. First, we adapted a set of BglBrick plasmids and showed tunable expression in B. sacchari. Finally, we assessed growth rate and P(3HB) production through overexpression of xylose transporters, catabolic or regulatory genes. Overexpression of xylR significantly improved growth rate (55.5% improvement), polymer yield (77.27% improvement), and resulted in 71% of cell dry weight as P(3HB). These values are unprecedented for P(3HB) accumulation using xylose as a sole carbon source and highlight the importance of precise expression control for improving utilization of hemicellulosic sugars in B. sacchari.

Accelerated weathering of limestone for CO2 mitigation opportunities for the stone and cement industries

USGS Publications Warehouse

Langer, W.H.; Juan, C.A.S.; Rau, G.H.; Caldeira, K.

2009-01-01

Large amounts of limestone fines coproduced during the processing of crushed limestone may be useful in the sequestration of carbon dioxide (CO 2). Accelerated weathering of limestone (AWL) is proposed as a low-tech method to capture and sequester CO2 from fossil fuel-fired power plants and other point-sources such as cement manufacturing. AWL reactants are readily available, inexpensive, and environmentally benign. Waste CO 2 is hydrated with water to produce carbonic acid, which then reacts with and is neutralized by limestone fines, thus converting CO2 gas to dissolved calcium bicarbonate. AWL waste products can be disposed of in the ocean. Feasibility requires access to an inexpensive source of limestone and to seawater, thus limiting AWL facilities within about 10 km of the coastline. The majority of U.S. coastal power generating facilities are within economical transport distance of limestone resources. AWL presents opportunities for collaborative efforts among the crushed stone industry, electrical utilities, cement manufactures, and research scientists.

Two enzymes with redundant fructose bisphosphatase activity sustain gluconeogenesis and virulence in Mycobacterium tuberculosis.

PubMed

Ganapathy, Uday; Marrero, Joeli; Calhoun, Susannah; Eoh, Hyungjin; de Carvalho, Luiz Pedro Sorio; Rhee, Kyu; Ehrt, Sabine

2015-08-10

The human pathogen Mycobacterium tuberculosis (Mtb) likely utilizes host fatty acids as a carbon source during infection. Gluconeogenesis is essential for the conversion of fatty acids into biomass. A rate-limiting step in gluconeogenesis is the conversion of fructose 1,6-bisphosphate to fructose 6-phosphate by a fructose bisphosphatase (FBPase). The Mtb genome contains only one annotated FBPase gene, glpX. Here we show that, unexpectedly, an Mtb mutant lacking GLPX grows on gluconeogenic carbon sources and has detectable FBPase activity. We demonstrate that the Mtb genome encodes an alternative FBPase (GPM2, Rv3214) that can maintain gluconeogenesis in the absence of GLPX. Consequently, deletion of both GLPX and GPM2 is required for disruption of gluconeogenesis and attenuation of Mtb in a mouse model of infection. Our work affirms a role for gluconeogenesis in Mtb virulence and reveals previously unidentified metabolic redundancy at the FBPase-catalysed reaction step of the pathway.

Two enzymes with redundant fructose bisphosphatase activity sustain gluconeogenesis and virulence in Mycobacterium tuberculosis

PubMed Central

Ganapathy, Uday; Marrero, Joeli; Calhoun, Susannah; Eoh, Hyungjin; de Carvalho, Luiz Pedro Sorio; Rhee, Kyu; Ehrt, Sabine

2015-01-01

The human pathogen Mycobacterium tuberculosis (Mtb) likely utilizes host fatty acids as a carbon source during infection. Gluconeogenesis is essential for the conversion of fatty acids into biomass. A rate-limiting step in gluconeogenesis is the conversion of fructose 1,6-bisphosphate to fructose 6-phosphate by a fructose bisphosphatase (FBPase). The Mtb genome contains only one annotated FBPase gene, glpX. Here we show that, unexpectedly, an Mtb mutant lacking GLPX grows on gluconeogenic carbon sources and has detectable FBPase activity. We demonstrate that the Mtb genome encodes an alternative FBPase (GPM2, Rv3214) that can maintain gluconeogenesis in the absence of GLPX. Consequently, deletion of both GLPX and GPM2 is required for disruption of gluconeogenesis and attenuation of Mtb in a mouse model of infection. Our work affirms a role for gluconeogenesis in Mtb virulence and reveals previously unidentified metabolic redundancy at the FBPase-catalysed reaction step of the pathway. PMID:26258286

Dehydrogenase GRD1 Represents a Novel Component of the Cellulase Regulon in Trichoderma reesei (Hypocrea jecorina) ▿ † §

PubMed Central

Schuster, André; Kubicek, Christian P.; Schmoll, Monika

2011-01-01

Trichoderma reesei (Hypocrea jecorina) is nowadays the most important industrial producer of cellulase and hemicellulase enzymes, which are used for pretreatment of cellulosic biomass for biofuel production. In this study, we introduce a novel component, GRD1 (glucose-ribitol dehydrogenase 1), which shows enzymatic activity on cellobiose and positively influences cellulase gene transcription, expression, and extracellular endo-1,4-β-d-glucanase activity. grd1 is differentially transcribed upon growth on cellulose and the induction of cellulase gene expression by sophorose. The transcription of grd1 is coregulated with that of cel7a (cbh1) under inducing conditions. GRD1 is further involved in carbon source utilization on several carbon sources, such as those involved in lactose and d-galactose catabolism, in several cases in a light-dependent manner. We conclude that GRD1 represents a novel enhancer of cellulase gene expression, which by coregulation with the major cellulase may act via optimization of inducing mechanisms. PMID:21602376

Enhanced biofuel production potential with nutritional stress amelioration through optimization of carbon source and light intensity in Scenedesmus sp. CCNM 1077.

PubMed

Pancha, Imran; Chokshi, Kaumeel; Mishra, Sandhya

2015-03-01

Microalgal mixotrophic cultivation is one of the most potential ways to enhance biomass and biofuel production. In the present study, first of all ability of microalgae Scenedesmus sp. CCNM 1077 to utilize various carbon sources under mixotrophic growth condition was evaluated followed by optimization of glucose concentration and light intensity to obtain higher biomass, lipid and carbohydrate contents. Under optimized condition i.e. 4 g/L glucose and 150 μmol m(-2) s(-1) light intensity, Scenedesmus sp. CCNM 1077 produced 1.2g/L dry cell weight containing 23.62% total lipid and 42.68% carbohydrate. Addition of glucose shown nutritional stress ameliorating effects and around 70% carbohydrate and 25% total lipid content was found with only 21% reduction in dry cell weight under nitrogen starved condition. This study shows potential application of mixotrophically grown Scenedesmus sp. CCNM 1077 for bioethanol and biodiesel production feed stock. Copyright © 2014 Elsevier Ltd. All rights reserved.

Leaf-architectured 3D Hierarchical Artificial Photosynthetic System of Perovskite Titanates Towards CO2 Photoreduction Into Hydrocarbon Fuels

PubMed Central

Zhou, Han; Guo, Jianjun; Li, Peng; Fan, Tongxiang; Zhang, Di; Ye, Jinhua

2013-01-01

The development of an “artificial photosynthetic system” (APS) having both the analogous important structural elements and reaction features of photosynthesis to achieve solar-driven water splitting and CO2 reduction is highly challenging. Here, we demonstrate a design strategy for a promising 3D APS architecture as an efficient mass flow/light harvesting network relying on the morphological replacement of a concept prototype-leaf's 3D architecture into perovskite titanates for CO2 photoreduction into hydrocarbon fuels (CO and CH4). The process uses artificial sunlight as the energy source, water as an electron donor and CO2 as the carbon source, mimicking what real leaves do. To our knowledge this is the first example utilizing biological systems as “architecture-directing agents” for APS towards CO2 photoreduction, which hints at a more general principle for APS architectures with a great variety of optimized biological geometries. This research would have great significance for the potential realization of global carbon neutral cycle. PMID:23588925