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Sample records for microbially promoted solubilization

  1. Microbial solubilization of coal

    DOEpatents

    Strandberg, G.W.; Lewis, S.N.

    1988-01-21

    The present invention relates to a cell-free preparation and process for the microbial solubilization of coal into solubilized coal products. More specifically, the present invention relates to bacterial solubilization of coal into solubilized coal products and a cell-free bacterial byproduct useful for solubilizing coal. 5 tabs.

  2. Microbial solubilization of phosphate

    DOEpatents

    Rogers, Robert D.; Wolfram, James H.

    1993-01-01

    A process is provided for solubilizing phosphate from phosphate containing ore by treatment with microorganisms which comprises forming an aqueous mixture of phosphate ore, microorganisms operable for solubilizing phosphate from the phosphate ore and maintaining the aqueous mixture for a period of time and under conditions operable to effect the microbial solubilization process. An aqueous solution containing soluble phosphorous can be separated from the reacted mixture by precipitation, solvent extraction, selective membrane, exchange resin or gravity methods to recover phosphate from the aqueous solution.

  3. Microbial solubilization of phosphate

    DOEpatents

    Rogers, R.D.; Wolfram, J.H.

    1993-10-26

    A process is provided for solubilizing phosphate from phosphate containing ore by treatment with microorganisms which comprises forming an aqueous mixture of phosphate ore, microorganisms operable for solubilizing phosphate from the phosphate ore and maintaining the aqueous mixture for a period of time and under conditions operable to effect the microbial solubilization process. An aqueous solution containing soluble phosphorus can be separated from the reacted mixture by precipitation, solvent extraction, selective membrane, exchange resin or gravity methods to recover phosphate from the aqueous solution. 6 figures.

  4. Microbial solubilization of coals

    SciTech Connect

    Campbell, J.A.; Fredrickson, J.K.; Stewart, D.L.; Thomas, B.L.; McCulloch, M.; Wilson, B.W.; Bean, R.M.

    1988-11-01

    Microbial solubilization of coal may serve as a first step in a process to convert low-rank coals or coal-derived products to other fuels or products. For solubilization of coal to be an economically viable technology, a mechanistic understanding of the process is essential. Leonardite, a highly oxidized, low-rank coal, has been solubilized by the intact microorganism, cell-free filtrate, and cell-free enzyme of /ital Coriolus versicolor/. A spectrophotometric conversion assay was developed to quantify the amount of biosolubilized coal. In addition, a bituminous coal, Illinois No. 6, was solubilized by a species of /ital Penicillium/, but only after the coal had been preoxidized in air. Model compounds containing coal-related functionalities have been incubated with the leonardite-degrading fungus, its cell-free filtrate, and purified enzyme. The amount of degradation was determined by gas chromatography and the degradation products were identified by gas chromatography/mass spectrometry. We have also separated the cell-free filtrate of /ital C. versicolor/ into a <10,000 MW and >10,000 MW fraction by ultrafiltration techniques. Most of the coal biosolubilization activity is contained in the <10,000 MW fraction while the model compound degradation occurs in the >10,000 MW fraction. The >10,000 MW fraction appears to contain an enzyme with laccase-like activity. 10 refs., 8 figs., 5 tabs.

  5. Microbial solubilization of coal

    DOEpatents

    Strandberg, Gerald W.; Lewis, Susan N.

    1990-01-01

    This invention deals with the solubilization of coal using species of Streptomyces. Also disclosed is an extracellular component from a species of Streptomyces, said component being able to solubilize coal.

  6. Plant growth promotion induced by phosphate solubilizing endophytic Pseudomonas isolates

    PubMed Central

    Oteino, Nicholas; Lally, Richard D.; Kiwanuka, Samuel; Lloyd, Andrew; Ryan, David; Germaine, Kieran J.; Dowling, David N.

    2015-01-01

    The use of plant growth promoting bacterial inoculants as live microbial biofertilizers provides a promising alternative to chemical fertilizers and pesticides. Inorganic phosphate solubilization is one of the major mechanisms of plant growth promotion by plant associated bacteria. This involves bacteria releasing organic acids into the soil which solubilize the phosphate complexes converting them into ortho-phosphate which is available for plant up-take and utilization. The study presented here describes the ability of endophytic bacteria to produce gluconic acid (GA), solubilize insoluble phosphate, and stimulate the growth of Pisum sativum L. plants. This study also describes the genetic systems within three of these endophyte strains thought to be responsible for their effective phosphate solubilizing abilities. The results showed that many of the endophytic strains produced GA (14–169 mM) and have moderate to high phosphate solubilization capacities (~400–1300 mg L−1). When inoculated into P. sativum L. plants grown in soil under soluble phosphate limiting conditions, the endophytes that produced medium-high levels of GA displayed beneficial plant growth promotion effects. PMID:26257721

  7. Fixed-bed bioreactor system for the microbial solubilization of coal

    DOEpatents

    Scott, C.D.; Strandberg, G.W.

    1987-09-14

    A fixed-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fixed-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the large scale production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fixed-bed bioreactor. 1 fig., 1 tab.

  8. Fluidized-bed bioreactor system for the microbial solubilization of coal

    DOEpatents

    Scott, C.D.; Strandberg, G.W.

    1987-09-14

    A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor. 2 figs.

  9. Characterization and subsequent utilization of microbially solubilized coal: Preliminary studies

    SciTech Connect

    Davison, B.H.; Nicklaus, D.M.; Woodward, C.A.; Lewis, S.N.; Faison, B.D.

    1989-01-01

    The solubilization of low-ranked coals by fungi, such as Paecilomyces and Candida, in defined submerged culture systems has been demonstrated. Current efforts focus on the characterization of the aqueous solubilized coal products and the development of technologies for their subsequent utilization. Solubilized coal products have been fractionated, and preliminary characterizations performed. Differences in product composition have been detected with respect to the organism used in culture duration. Prospects for the conversion of the aerobically-solubilized coal into less-oxidized products have been developed which can remain active and viable in the presence of the aqueous coal product or vanillin, a coal model compound. The results suggest that a methanogenic consortium was able to produce methane and carbon dioxide from the product of coal biosolubilization by Paecilomyces as a sole carbon source. Work continues on the development of cultures able to convert the aqueous coal product and its various fractions into methane or fuel alcohols. 17 refs., 8 figs.

  10. Optimizations of particle size and pulp density for solubilization of rock phosphate by a microbial consortium from activated sludge.

    PubMed

    Xiao, Chunqiao; Wu, Xiaoyan; Liu, Tingting; Xu, Guang; Chi, Ruan

    2016-12-29

    Microbial solubilization of rock phosphate is getting more and more attention recently. However, the microorganisms used in previous studies were mostly single or known species, and seldom studies focused on the mixed microorganisms or microbial consortia from natural environments. In this study, a microbial consortium taken from activated sludge was used to solubilize two different mid-low-grade rock phosphates. The results showed that the microbial consortium could effectively solubilize the rock phosphates in National Botanical Research Institute's phosphate growth medium and released soluble phosphorus in the broth. The biomass increased gradually, whereas the pH decreased sharply during the solubilizing process. The maximum phosphorus solubilization was recorded at particle size of 150 µm. Higher or lower than this optimal particle size, the phosphorus solubilization decreased. The phosphorus solubilization gradually decreased with a larger pulp density from 1 to 5%, and the optimal pulp density was 1%. The solubilization level of microbial consortium varied with different rock phosphates. The results revealed that the soluble phosphorus released from high-silicon ore was higher than which from high-magnesium ore. A strong positive correlation between biomass and phosphorus solubilization in the broth was observed from regression analysis results, and the phosphorus solubilization also had a significant negative correlation with pH in the broth.

  11. Metal solubilization from powdered printed circuit boards by microbial consortium from bauxite and pyrite ores.

    PubMed

    Adhapure, N N; Waghmare, S S; Hamde, V S; Deshmukh, A M

    2013-01-01

    With the current rapid developments in technology, there is an increasing accumulation of outdated electronic equipment. The primary reason for this increase is the low rate of recycling due to the complex nature of such waste. Bioleaching offers a promising solution for this problem. Study was conducted on the solubilization of heavy metals from electronic waste (e-waste). For this purpose, a microbial consortium from bauxite and pyrite ore samples was obtained using a simple "top down" approach. Essentially, printed circuit boards (PCB) were obtained and used as representative samples of e-waste. Various concentrations (1-5%) of PCB powder were subjected to bioleaching, and the effects on metal solubilization, changes in pH and concentration of ferrous iron produced were assessed. It was observed that a maximum of 96.93% Cu and 93.33% Zn was solubilized by microbial consortium from 10 g/l of PCB powder, whereas only 10.26% Ni was solubilized from 30 g/l of PCB powder. For lead, only 0.58% solubilization was achieved from 20 g/l of PCB powder. An analysis of the precipitate formed during bioleaching using scanning electron microscopy with energy dispersive x-ray analysis revealed the presence of Tin (59.96%), Cu (23.97%), Pb (9.30%) and Fe (5.92%).

  12. Gluconic acid production and phosphate solubilization by the plant growth-promoting bacterium Azospirillum spp.

    NASA Astrophysics Data System (ADS)

    Rodriguez, Hilda; Gonzalez, Tania; Goire, Isabel; Bashan, Yoav

    2004-11-01

    In vitro gluconic acid formation and phosphate solubilization from sparingly soluble phosphorus sources by two strains of the plant growth-promoting bacteria A. brasilense (Cd and 8-I) and one strain of A. lipoferum JA4 were studied. Strains of A. brasilense were capable of producing gluconic acid when grown in sparingly soluble calcium phosphate medium when their usual fructose carbon source is amended with glucose. At the same time, there is a reduction in pH of the medium and release of soluble phosphate. To a greater extent, gluconic acid production and pH reduction were observed for A. lipoferum JA4. For the three strains, clearing halos were detected on solid medium plates with calcium phosphate. This is the first report of in vitro gluconic acid production and direct phosphate solubilization by A. brasilense and the first report of P solubilization by A. lipoferum. This adds to the very broad spectrum of plant growth-promoting abilities of this genus.

  13. Value added phytoremediation of metal stressed soils using phosphate solubilizing microbial consortium.

    PubMed

    Gupta, Pratishtha; Kumar, Vipin

    2017-01-01

    The presence of heavy metals in the soil is a matter of growing concern due to their toxic and non-biodegradable nature. Lack of effectiveness of various conventional methods due to economic and technical constraints resulted in the search for an eco-friendly and cost-effective biological techniques for heavy metal removal from the environment. Until now, phytoremediation has emerged as an innovative technique to address the problem. However, the efficiency of phytoremediation process is hindered under the high metal concentration conditions. Hence, phosphate solubilizing microbes (PSM) assisted phytoremediation technique is gaining more insight as it can reduce the contamination load even under elevated metal stressed conditions. These microbes convert heavy metals into soluble and bioavailable forms, which consequently facilitate phytoremediation. Several studies have reported that the use of microbial consortium for remediation is considered more effective as compared to single strain pure culture. Therefore, this review paper focuses on the current trends in research related to PSM mediated uptake of heavy metal by plants. The efficiency of PSM consortia in enhancing the phytoremediation process has also been reviewed. Moreover, the role of phosphatase enzymes in the mineralization of organic forms of phosphate in soil is further discussed. Biosurfactant mediated bioremediation of metal polluted soils is a matter of extensive research nowadays. Hence, the recent advancement of using biosurfactants in enhanced phytoremediation of metal stressed soils is also described.

  14. Synthetic promoter design for new microbial chassis

    PubMed Central

    Gilman, James; Love, John

    2016-01-01

    The judicious choice of promoter to drive gene expression remains one of the most important considerations for synthetic biology applications. Constitutive promoter sequences isolated from nature are often used in laboratory settings or small-scale commercial production streams, but unconventional microbial chassis for new synthetic biology applications require well-characterized, robust and orthogonal promoters. This review provides an overview of the opportunities and challenges for synthetic promoter discovery and design, including molecular methodologies, such as saturation mutagenesis of flanking regions and mutagenesis by error-prone PCR, as well as the less familiar use of computational and statistical analyses for de novo promoter design. PMID:27284035

  15. Survival of introduced phosphate-solubilizing bacteria (PSB) and their impact on microbial community structure during the phytoextraction of Cd-contaminated soil.

    PubMed

    Jeong, Seulki; Moon, Hee Sun; Shin, Doyun; Nam, Kyoungphile

    2013-12-15

    This study was conducted to investigate whether or not phosphate-solubilizing bacteria (PSB) as a kind of plant growth promoting rhizobacteria enhance the uptake of Cd by plants. In addition, the effect of PSB augmentation during phytoextraction on the microbial community of indigenous soil bacteria was also studied. In the initial Cd-contaminated soil, the major phyla were Proteobacteria (35%), Actinobacteria (38%) and Firmicutes (8%). While Proteobacteria were dominant at the second and sixth week (41 and 54%, respectively) in inoculated soil, Firmicutes (mainly belonging to the Bacilli class-61%), dramatically increased in the eight-week soil. For the uninoculated soil, the proportion of α-Proteobacteria increased after eight weeks (32%). Interestingly, Actinobacteria class, which was originally present in the soil (37%), seemed to disappear during phytoremediation, irrespective of whether PSB was inoculated or not. Cluster analysis and Principal Component Analysis revealed that the microbial community of eight-week inoculated soil was completely separated from the other soil samples, due to the dramatic increase of Bacillus aryabhattai. These findings revealed that it took at least eight weeks for the inoculated Bacillus sp. to functionally adapt to the introduced soil, against competition with indigenous microorganisms in soil. An ecological understanding of interaction among augmented bacteria, plant and indigenous soil bacteria is needed, for proper management of phytoextraction.

  16. Bacteria with Phosphate Solubilizing Capacity Alter Mycorrhizal Fungal Growth Both Inside and Outside the Root and in the Presence of Native Microbial Communities

    PubMed Central

    Lara, Lidia Susana; Rodriguez, Alia; Uribe-Vélez, Daniel; Sanders, Ian R.

    2016-01-01

    Arbuscular mycorrhizal fungi (AMF) and phosphate solubilizing Pseudomonas bacteria (PSB) could potentially interact synergistically because PSB solubilize phosphate into a form that AMF can absorb and transport to the plant. However, very little is known about the interactions between these two groups of microorganisms and how they influence the growth of each other. We tested whether different strains of bacteria, that have the capacity to solubilize phosphate, are able to grow along AMF hyphae and differentially influence the growth of AMF both outside the roots of carrot in in vitro conditions and inside the roots of potato in the presence of a microbial community. We found strong effects of AMF on the growth of the different bacterial strains. Different bacterial strains also had very strong effects on the growth of AMF extraradical hyphae outside the roots of carrot and on colonization of potato roots by AMF. The differential effects on colonization occurred in the presence of a microbial community. Our results show that these two important groups of rhizosphere microorganisms indeed interact with each other. Such interactions could potentially lead to synergistic effects between the two groups but this could depend on whether the bacteria truly solubilize phosphate in the rhizosphere in the presence of microbial communities. PMID:27253975

  17. Maize yield response to a phosphorus-solubilizing microbial inoculant in field trials.

    PubMed

    Leggett, M; Newlands, N K; Greenshields, D; West, L; Inman, S; Koivunen, M E

    2015-11-01

    Findings from multi-year, multi-site field trial experiments measuring maize yield response to inoculation with the phosphorus-solubilizing fungus, Penicillium bilaiae Chalabuda are presented. The main objective was to evaluate representative data on crop response to the inoculant across a broad set of different soil, agronomic management and climate conditions. A statistical analysis of crop yield response and its variability was conducted to guide further implementation of a stratified trial and sampling plan. Field trials, analysed in the present study, were conducted across the major maize producing agricultural cropland of the United States (2005-11) comprising 92 small (with sampling replication) and 369 large (without replication) trials. The multi-plot design enabled both a determination of how sampling area affects the estimation of maize yield and yield variance and an estimation of the ability of inoculation with P. bilaiae to increase maize yield. Inoculation increased maize yield in 66 of the 92 small and 295 of the 369 large field trials (within the small plots, yield increased significantly at the 95% confidence level, by 0·17 ± 0·044 t/ha or 1·8%, while in the larger plots, yield increases were higher and less variable (i.e., 0·33 ± 0·026 t/ha or 3·5%). There was considerable inter-annual variability in maize yield response attributed to inoculation compared to the un-inoculated control, with yield increases varying from 0·7 ± 0·75 up to 3·7 ± 0·73%. No significant correlation between yield response and soil acidity (i.e., pH) was detected, and it appears that pH reduction (through organic acid or proton efflux) was unlikely to be the primary pathway for better phosphorus availability measured as increased yield. Seed treatment and granular or dribble band formulations of the inoculant were found to be equally effective. Inoculation was most effective at increasing maize yield in fields that had low or very low soil phosphorus status

  18. Efficiency of plant growth-promoting P-solubilizing Bacillus circulans CB7 for enhancement of tomato growth under net house conditions.

    PubMed

    Mehta, Preeti; Walia, Abhishek; Kulshrestha, Saurabh; Chauhan, Anjali; Shirkot, Chand Karan

    2015-01-01

    P-solubilizing bacterial isolate CB7 isolated from apple rhizosphere soil of Himachal Pradesh, India was identified as Bacillus circulans on the basis of phenotypic characteristics, biochemical tests, fatty acid methyl esters analysis, and 16S rRNA gene sequence. The isolate exhibited plant growth-promoting traits of P-solubilization, auxin, 1-aminocyclopropane-1-carboxylate deaminase activity, siderophore, nitrogenase activity, and antagonistic activity against Dematophora necatrix. In vitro studies revealed that P-solubilization and other plant growth-promoting traits were dependent on the presence of glucose in PVK medium and removal of yeast extract had no significant effect on plant growth-promoting traits. Plant growth-promoting traits of isolate CB7 were repressed in the presence of KH2 PO4 . P-solubilization activity was associated with the release of organic acids and a drop in the pH of the Pikovskaya's medium. HPLC analysis detected gluconic and citric acid as major organic acids in the course of P-solubilization. Remarkable increase was observed in seed germination (22.32%), shoot length (15.91%), root length (25.10%), shoot dry weight (52.92%) and root dry weight (31.4%), nitrogen (18.75%), potassium (57.69%), and phosphorus (22.22%) content of shoot biomass over control. These results demonstrate that isolate CB7 has the promising PGPR attributes to be developed as a biofertilizer to enhance soil fertility and promote plant growth.

  19. Toxicological effects of selective herbicides on plant growth promoting activities of phosphate solubilizing Klebsiella sp. strain PS19.

    PubMed

    Ahemad, Munees; Saghir Khan, Md

    2011-02-01

    This study examines the effect of four herbicides, quizalafop-p-ethyl, clodinafop, metribuzin and glyphosate, on plant growth promoting activities like phosphate solubilization, siderophores, indole acetic acid, exo-polysaccharides, hydrogen cyanide and ammonia production by herbicide tolerant Klebsiella sp. strain PS19. The strain was isolated from mustard rhizosphere. The selected herbicides were applied two to three times at the recommended rates. Klebsiella sp. strain PS19 tolerated a concentration of 1600 μg/ml each of quizalafop-p-ethyl and clodinafop, and 3200 and 2800 μg/ml of metribuzin and glyphosate, respectively. The activities of Klebsiella sp. strain PS19 observed under in vitro environment were persistent in the presence of all herbicides at lower rates. The plant growth promoting activities even-though decreased regularly, but was not lost completely, as the concentration of each herbicide was increased from the recommended to three times of higher doses. Among all herbicides, quizalafop-p-ethyl, generally, showed maximum toxicity to plant growth promoting activities of Klebsiella sp. strain PS19. As an example, 40, 80 and 120 μg/l of quizalafop-p-ethyl added to liquid culture Pikovskaya medium, decreased phosphate solubilizing activity of strain PS19 by 93, 95 and 97%, respectively over untreated control. The study revealed that the higher rates of herbicides though decreased the plant growth promoting activity but it did not completely inhibit the metabolic activities of strain PS19. The herbicide tolerance together with growth promoting activities observed under herbicide stress suggests that Klebsiella sp. strain PS19 could be used as bacterial preparation for facilitating the growth and yields of crops even in soils polluted with herbicides.

  20. Modestobacter lacusdianchii sp. nov., a Phosphate-Solubilizing Actinobacterium with Ability to Promote Microcystis Growth

    PubMed Central

    Cheng, Juan; Li, Han-Quan; Yang, Jian-Yuan; Zha, Dai-Ming; Zhang, Yu-Qin; Ai, Meng-Jie; Hozzein, Wael N.; Li, Wen-Jun

    2016-01-01

    A novel actinobacterium, designated strain JXJ CY 19T, was isolated from a culture mat of Microcystis aeruginosa FACHB-905 collected from Dianchi Lake, South-west China. 16S rRNA gene sequences comparison of strain JXJ CY 19T and the available sequences in the GenBank database showed that the strain was closely related to Modestobacter marinus 42H12-1T (99.1% similarity) and Modestobacter roseus KLBMP 1279T (99.0%). The isolate had meso-diaminopimelic in the cell wall with whole-cell sugars of mannose, rhamnose, ribose, glucose, galactose, and arabinose. The menaquinone detected was MK-9(H4), while the major cellular fatty acids include C17:1 ω8c, C15:0 iso, C15:1 iso G and C16:0 iso. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified phospholipid. The DNA-DNA hybridization values between strains JXJ CY 19T and the closely related type strains Modestobacter marinus CGMCC 4.5581T and Modestobacter roseus NBRC 108673T were determined to be 50.8 ± 0.8% and 44.1 ± 1.7%, respectively. The DNA G+C content was 71.9 mol%. On the basis of the above taxonomic data and differences in physiological characters from the closely related type strains, strain JXJ CY 19T was recognized as a novel species of the genus Modestobacter, for which the name Modestobacter lacusdianchii sp. nov. (JXJ CY 19T = KCTC 39600T = CPCC 204352T) is proposed. The type strain JXJ CY 19T can solubilize calcium phosphate tribasic (Ca3(PO4)2), phytin and L-α-phosphatidylcholine. The phosphate-solubilizing property of the novel actinobacterium could be a possible factor for the increase in growth of Microcystis aeruginosa FACHB-905 in ecosystem where the amount of available soluble phosphate is limited such as Dianchi Lake. PMID:27537546

  1. Plant growth promoting traits of phosphate-solubilizing rhizobacteria isolated from apple trees in trans Himalayan region of Himachal Pradesh.

    PubMed

    Mehta, Preeti; Walia, Abhishek; Chauhan, Anjali; Shirkot, C K

    2013-05-01

    Two hundred and six phosphate-solubilizing rhizobacteria (PSB) were isolated from rhizosphere soil (RS) and root endosphere (ER) of apple trees from different sites of four locations viz., Chamba, Shimla, Kinnaur and Kullu of Himachal Pradesh, Northern India, and were screened for plant growth promoting traits (PGPTs) by using culture dependent procedures. Indole acetic acid (IAA) production was detected in 50 isolates (24.2 %), siderophore synthesis in 53 isolates (25.7 %), hydrocyanic acid (HCN) in 40 isolates (19.4 %) and percentage growth inhibition against Dematophora necatrix in 61 isolates (29.6 %). Overall, 54.3 % of PSB isolates from RS and 64.4 % from ER showed none of the PGPTs tested. Among the PSB showing PGPTs, 10.6 % had single trait and 30.6 % had multiple traits showing two (10.7 %), three (14.1 %) and four (5.8 %) types of PGPTs. The Shannon-Weaver diversity index (H') revealed that PGPT-possessing PSBs in RS were more abundant than ER. Clustering analysis by principal component analysis showed that ER was most important factor influencing the ecological distribution and physiological characterization of PGPT-possessing PSB. There was a positive correlation (0.94, p < 0.05) between HCN and antifungal activity producers, and IAA and antifungal activity producers (0.99, p < 0.05). Significant positive correlation (0.42, p < 0.05) between HCN producers and altitude was also noted.

  2. Root colonization and growth promotion of sunflower (Helianthus annuus L.) by phosphate solubilizing Enterobacter sp. Fs-11.

    PubMed

    Shahid, Muhammad; Hameed, Sohail; Imran, Asma; Ali, Saira; van Elsas, Jan Dirk

    2012-08-01

    An Enterobacter sp. Fs-11 was isolated from sunflower rhizosphere, identified on the basis of 16S rRNA gene sequence analysis (GeneBank accession no. GQ179978) and studied for its root colonization and growth promotion ability in sunflower. Morphologically, it was rod shaped Gram-negative, motile bacterium, producing 4.5 μg mL(-1) indole acetic acid in tryptophan-supplemented medium. It utilized 27 out of 95 substrates in BIOLOG GN2 micro plate system. It was able to convert insoluble tri-calcium phosphate to soluble phosphorus up to 43.5 μg mL(-1) with decrease in pH of the medium up to 4.5 after 10 days incubation at 28 ± 2 °C in the Pikovskaya's broth. High performance liquid chromatography of cell free supernatant showed that Fs-11 produced malic acid and gluconic acid (2.43 and 16.64 μg mL(-1), respectively) in Pikovskaya's broth. Analysis of 900 bp fragment of pyrroloquinoline quinine pqqE gene sequence showed 98 % homology with that of E. cloacae pqqE gene. Confocal laser scanning microscope revealed strong colonization of fluorescently labeled Fs-11 with sunflower roots. Sunflower inoculation with Fs-11 and its rifampicin resistant derivative in sterile sand and natural soil showed that Fs-11 colonized sunflower roots up to 30 days after transplanting in both sterile sand as well as natural soil. Moreover, Fs-11 inoculation resulted in increased plant height, fresh weight, dry weight and total phosphorus contents as compared to un-inoculated plants. The data showed that Enterobacter sp. Fs-11 is an efficient phosphate solubilizing and plant growth promoting rhizobacterium and has great potential to be used as bio-inoculant for sunflower under phosphorus deficient conditions.

  3. Transformation of inorganic P fractions of soil and plant growth promotion by phosphate-solubilizing ability of Penicillium oxalicum I1.

    PubMed

    Gong, Mingbo; Du, Peng; Liu, Xue; Zhu, Changxiong

    2014-12-01

    The solubilization of tricalcium phosphate is often considered as the standard for screening of most phosphate-solubilizing microorganisms (PSMs). However, usually the effect of large-scale application of PSM on the promotion of crop growth varies. This study presents an efficient method for screening and testing phosphate-solubilizing fungus that enhance plant growth. A fungus Penicillium oxalicum I1 (P-I1) was isolated and identified that had high ability of phosphate-solubilization and could utilize maize root exudates as sources, and propagate well in vitro and in soil. P-I1 excreted oxalic acid and reached 593.9 μg/ml, and the pH value was decreased from 6.90 to 1.65 in 26 h. The amount of P-I1 increased by 48-fold in 28 d and was maintained for 49 d in soil. PSM showed selectivity on the transformation of the different forms of phosphorus, a wide range of insoluble phosphates, such as Ca₈H₂(PO₄)₆·5H₂O, AlPO₄, FePO₄, and Ca10(PO₄)₆(OH)₂, were converted to soluble CaHPO₄in soil, and CaHPO₄was also inhibited from being converted into insoluble phosphate by P-I1. The Ca₂-P content reached 27.11 μg/g soil on day 28 at 20°C, which increased by 110.32%, and plant growth promotion was tested and verified, the results showed that maize yield increased remarkably than control after inoculated P-I1, maize yield increased maximum by 14.47%. The data presented that P-I1 appear attractive for exploring their plant growth-promoting activity and potential field application.

  4. Microbially Promoted Solubilization of Steel Corrosion Products and Fate of Associated Actinides

    SciTech Connect

    Yyri A. Gorby; Gill G. Geesey; Frank Caccavo, Jr.; James K. Fredrickson

    2003-02-28

    The ultimate goal of this project was to demonstrate that metal-reducing bacteria could be used to remove heavy metal and radionuclide contaminants from the surfaces of corroding steel surfaces. Toward this end, fundamental scientific issues regarding (1) factors influencing the adhesion and colonization of DIB on mineral surfaces, (2) the enzymatic activity of cells once they have adhered to mineral surfaces, (3) and (4) methods for recovering bacteria and attendant radionuclides following release from mineral surfaces were addressed. The fate of radionuclides (plutonium) contaminants following reduction by DIRB.

  5. Cancer-promoting effects of microbial dysbiosis.

    PubMed

    Sheflin, Amy M; Whitney, Alyssa K; Weir, Tiffany L

    2014-10-01

    Humans depend on our commensal bacteria for nutritive, immune-modulating, and metabolic contributions to maintenance of health. However, this commensal community exists in careful balance that, if disrupted, enters dysbiosis; this has been shown to contribute to the pathogenesis of colon, gastric, esophageal, pancreatic, laryngeal, breast, and gallbladder carcinomas. This development is closely tied to host inflammation, which causes and is aggravated by microbial dysbiosis and increases vulnerability to pathogens. Advances in sequencing technology have increased our ability to catalog microbial species associated with various cancer types across the body. However, defining microbial biomarkers as cancer predictors presents multiple challenges, and existing studies identifying cancer-associated bacteria have reported inconsistent outcomes. Combining metabolites and microbiome analyses can help elucidate interactions between gut microbiota, metabolism, and the host. Ultimately, understanding how gut dysbiosis impacts host response and inflammation will be critical to creating an accurate picture of the role of the microbiome in cancer.

  6. Cancer-Promoting Effects of Microbial Dysbiosis

    PubMed Central

    Sheflin, Amy M.; Whitney, Alyssa K.; Weir, Tiffany L.

    2014-01-01

    Humans depend upon our commensal bacteria for nutritive, immune-modulating and metabolic contributions to maintenance of health. However, this commensal community exists in careful balance that, if disrupted, enters dysbiosis; which has been shown to contribute to the etiology of colon, gastric, esophageal, pancreatic, laryngeal, breast and gallbladder carcinomas. This etiology is closely tied to host inflammation, which causes and is aggravated by microbial dysbiosis while increasing vulnerability to pathogens. Advances in sequencing technology have increased our ability to catalog microbial species associated with various cancer types across the body. However, defining microbial biomarkers as cancer predictors presents multiple challenges and existing studies identifying cancer-associated bacteria have reported inconsistent outcomes. Combining metabolites and microbiome analyses can help elucidate interactions between gut microbiota, metabolism and the host. Ultimately, understanding how gut dysbiosis impacts host response and inflammation will be critical to creating an accurate picture of the role of the microbiome in cancer. PMID:25123079

  7. Tricalcium phosphate solubilization and nitrogen fixation by newly isolated Aneurinibacillus aneurinilyticus CKMV1 from rhizosphere of Valeriana jatamansi and its growth promotional effect.

    PubMed

    Chauhan, Anjali; Guleria, Shiwani; Balgir, Praveen P; Walia, Abhishek; Mahajan, Rishi; Mehta, Preeti; Shirkot, Chand Karan

    Aneurinibacillus aneurinilyticus strain CKMV1 was isolated from rhizosphere of Valeriana jatamansi and possessed multiple plant growth promoting traits like production of phosphate solubilization (260mg/L), nitrogen fixation (202.91nmolethylenemL(-1)h(-1)), indole-3-acetic acid (IAA) (8.1μg/mL), siderophores (61.60%), HCN (hydrogen cyanide) production and antifungal activity. We investigated the ability of isolate CKMV1 to solubilize insoluble P via mechanism of organic acid production. High-performance liquid chromatography (HPLC) study showed that isolate CKMV1 produced mainly gluconic (1.34%) and oxalic acids. However, genetic evidences for nitrogen fixation and phosphate solubilization by organic acid production have been reported first time for A. aneurinilyticus strain CKMV1. A unique combination of glucose dehydrogenase (gdh) gene and pyrroloquinoline quinone synthase (pqq) gene, a cofactor of gdh involved in phosphate solubilization has been elucidated. Nitrogenase (nif H) gene for nitrogen fixation was reported from A. aneurinilyticus. It was notable that isolate CKMV1 exhibited highest antifungal against Sclerotium rolfsii (93.58%) followed by Fusarium oxysporum (64.3%), Dematophora necatrix (52.71%), Rhizoctonia solani (91.58%), Alternaria sp. (71.08%) and Phytophthora sp. (71.37%). Remarkable increase was observed in seed germination (27.07%), shoot length (42.33%), root length (52.6%), shoot dry weight (62.01%) and root dry weight (45.7%) along with NPK (0.74, 0.36, 1.82%) content of tomato under net house condition. Isolate CKMV1 possessed traits related to plant growth promotion, therefore, could be a potential candidate for the development of biofertiliser or biocontrol agent and this is the first study to include the Aneurinibacillus as PGPR.

  8. Organic acid production and plant growth promotion as a function of phosphate solubilization by Acinetobacter rhizosphaerae strain BIHB 723 isolated from the cold deserts of the trans-Himalayas.

    PubMed

    Gulati, Arvind; Sharma, Natasha; Vyas, Pratibha; Sood, Swati; Rahi, Praveen; Pathania, Vijaylata; Prasad, Ramdeen

    2010-11-01

    An efficient phosphate-solubilizing plant growth-promoting Acinetobacter rhizosphaerae strain BIHB 723 exhibited significantly higher solubilization of tricalcium phosphate (TCP) than Udaipur rock phosphate (URP), Mussoorie rock phosphate (MRP) and North Carolina rock phosphate (NCRP). Qualitative and quantitative differences were discerned in the gluconic, oxalic, 2-keto gluconic, lactic, malic and formic acids during the solubilization of various inorganic phosphates by the strain. Gluconic acid was the main organic acid produced during phosphate solubilization. Formic acid production was restricted to TCP solubilization and oxalic acid production to the solubilization of MRP, URP and NCRP. A significant increase in plant height, shoot fresh weight, shoot dry weight, root length, root dry weight, and root, shoot and soil phosphorus (P) contents was recorded with the inoculated treatments over the uninoculated NP(0)K or NP(TCP)K treatments. Plant growth promotion as a function of phosphate solubilization suggested that the use of bacterial strain would be a beneficial addition to the agriculture practices in TCP-rich soils in reducing the application of phosphatic fertilizers.

  9. Prospecting cold deserts of north western Himalayas for microbial diversity and plant growth promoting attributes.

    PubMed

    Yadav, Ajar Nath; Sachan, Shashwati Ghosh; Verma, Priyanka; Saxena, Anil Kumar

    2015-06-01

    Microbial communities in different samples collected from cold deserts of north western Himalayas, India, were analyzed using 16S rRNA gene sequencing and phospholipid fatty acids (PLFA) analysis. A total of 232 bacterial isolates were characterized employing 16S rDNA-Amplified Ribosomal DNA Restriction Analysis with the three restriction endonucleases Alu I, Msp I and Hae III, which led to formation of 29-54 groups for the different sites, adding up to169 groups. 16S rRNA gene based phylogenetic analysis, revealed that 82 distinct species of 31 different genera, belonged to four phyla Actinobacteria, Bacteroidetes, Firmicutes and Proteobacteria. PLFA profiling was performed for concerned samples which gave an estimate of microbial communities without cultivating the microorganisms. PLFA analysis led to characterization of diverse group of microbes in different samples such as gram-negative, gram-positive bacteria, actinomycetes, cyanobacteria, anaerobic bacteria, sulphate reducing bacteria and fungi. The representative strains were screened for their plant growth promoting attributes, which included production of ammonia, HCN, gibberellic acid, IAA and siderophore; solubilization of phosphorus and activity of ACC deaminase. In vitro antifungal activity assay was performed against Rhizoctonia solani and Macrophomina phaseolina. Cold adapted microorganisms may serve as inoculants for crops growing under cold climatic conditions. To our knowledge, this is the first report for the presence of Arthrobacter nicotianae, Brevundimonas terrae, Paenibacillus tylopili and Pseudomonas cedrina in cold deserts and exhibit multifunctional PGP attributes at low temperatures.

  10. Phosphate Solubilizing Bacillus megaterium mj1212 Regulates Endogenous Plant Carbohydrates and Amino Acids Contents to Promote Mustard Plant Growth.

    PubMed

    Kang, Sang-Mo; Radhakrishnan, Ramalingam; You, Young-Hyun; Joo, Gil-Jae; Lee, In-Jung; Lee, Ko-Eun; Kim, Jin-Ho

    2014-12-01

    The current study was conducted to explore the potential of a phosphate solubilizing soil bacterium, Bacillus megaterium mj1212 for enhancing the growth of mustard plants. The newly isolated bacterial strain mj1212 was identified as B. megaterium using phylogenetic analysis and, its phosphate solubilization ability was shown by the clear zone formation on National Botanical Research Institute's Phosphate medium. Moreover, the phosphate solubilization ability of B. megaterium mj1212 was enhanced by optimal culture conditions at pH 7.0 and 35 °C which might be due to the presence of malic and quinic acid in the culture medium. The beneficial effect of B. megaterium mj1212 in mustard plants was determined by an increasing shoot length, root length and fresh weight of plants. In the biochemical analysis revealed that chlorophyll, sucrose, glucose, fructose and amino acids (Asp, Thr, Ser, Glu, Gly, Ala, Cys, Val, Met, Ilu, Leu, Tyr, Phe, Lys, His, Arg and Pro) were higher in B. megaterium mj1212 treated plants, when compared to their control. The result of present study suggests that B. megaterium mj1212 treatment could be act as phosphate biofertilizer to improve the plant growth.

  11. Allele surfing promotes microbial adaptation from standing variation.

    PubMed

    Gralka, Matti; Stiewe, Fabian; Farrell, Fred; Möbius, Wolfram; Waclaw, Bartlomiej; Hallatschek, Oskar

    2016-08-01

    The coupling of ecology and evolution during range expansions enables mutations to establish at expanding range margins and reach high frequencies. This phenomenon, called allele surfing, is thought to have caused revolutions in the gene pool of many species, most evidently in microbial communities. It has remained unclear, however, under which conditions allele surfing promotes or hinders adaptation. Here, using microbial experiments and simulations, we show that, starting with standing adaptive variation, range expansions generate a larger increase in mean fitness than spatially uniform population expansions. The adaptation gain results from 'soft' selective sweeps emerging from surfing beneficial mutations. The rate of these surfing events is shown to sensitively depend on the strength of genetic drift, which varies among strains and environmental conditions. More generally, allele surfing promotes the rate of adaptation per biomass produced, which could help developing biofilms and other resource-limited populations to cope with environmental challenges.

  12. Promoting uranium immobilization by the activities of microbial phophatases

    SciTech Connect

    Sobecky, Patricia A.; Martial Taillefert

    2006-06-01

    The following is a summary of progress in our project ''Promoting uranium immobilization by the activities of microbial phosphatases'' during the second year of the project. (1). Assignment of microbial phosphatases to molecular classes. One objective of this project is to determine the relationship of phosphatase activity to metal resistance in subsurface strains and possible contributions of horizontal gene transfer (HGT) to the dissemination of nonspecific acid phosphatase genes. Non-specific acid phosphohydrolases are a broad group of secreted microbial phosphatases that function in acidic-to-neutral pH ranges and utilize a wide range of organophosphate substrates. To address this objective we have designed a collection of PCR primer sets based on known microbial acid phosphatase sequences. Genomic DNA is extracted from subsurface FRC isolates and amplicons of the expected sizes are sequenced and searched for conserved signature motifs. During this reporting period we have successfully designed and tested a suite of PCR primers for gram-positive and gram-negative groups of the following phosphatase classes: (1) Class A; (2) Class B; and (3) Class C (gram negative). We have obtained specific PCR products for each of the classes using the primers we have designed using control strains as well as with subsurface isolates.

  13. Performance of calcium peroxide for removal of endocrine-disrupting compounds in waste activated sludge and promotion of sludge solubilization.

    PubMed

    Zhang, Ai; Wang, Jie; Li, Yongmei

    2015-03-15

    Removal of six phenolic endocrine disrupting compounds (EDCs) (estrone, 17β-estradiol, 17α-ethinylestradiol, estriol, bisphenol A, and 4-nonylphenols) from waste activated sludge (WAS) was investigated using calcium peroxide (CaO2) oxidation. Effects of initial pH and CaO2 dosage were investigated. The impacts of CaO2 treatment on sludge solubilization and anaerobic digestion were also evaluated. Specifically, the role of reactive oxygen species (ROS) in EDC degradation during CaO2 oxidation was tested. Effects of 6 metal ions contained in the sludge matrix on EDC degradation were also evaluated. The results showed that CaO2 treatment can be a promising technology for EDC removal and facilitating sludge reuse. The EDC removal efficiencies increased with the increase in CaO2 dosage. At CaO2 doses of more than 0.34 g per gram of total solid (g g(-1) TS), more than 50% of EDCs were removed in a wide pH range of 2-12. Higher removal efficiencies were achieved at initial pH values of 12 and 2. The products of EDCs during CaO2 oxidation had less estrogenic activity than the originals. Under the conditions of neutral pH and CaO2 dosage = 0.34 g g(-1) TS, the sludge solubilization can be improved by increasing the soluble total organic carbon (STOC) and volatile suspended solids (VSS) reduction by 25% and 27% in 7 d, respectively; the volatile fatty acid (VFA) production was enhanced by 96% in the 15 d following anaerobic digestion. The ROS released by CaO2 are the main factors contributing to EDC removal, among which, hydroxyl radicals (OH) play the most important role. Metal ions contained in the sludge matrix also affected EDC removal. For most cases, Fe, Cu, and Zn had positive effects; Mn and Ag had negative effects; and Mg had an insignificant effect on EDC removal.

  14. Promoting Effect of Sodium Chloride on the Solubilization and Depolymerization of Cellulose from Raw Biomass Materials in Water.

    PubMed

    Jiang, Zhicheng; Yi, Jian; Li, Jianmei; He, Ting; Hu, Changwei

    2015-06-08

    The development of a green system to solubilize cellulose from raw biomass is important, yet it is challenging because of the insolubility of cellulose in most solvents. Herein, a green NaCl-H2 O system is developed in which NaCl significantly enhances the dissolution and depolymerisation of cellulose from raw biomass. Nearly all the cellulose in the selected biomass types was dissolved and degraded into oligomers with molecular weights of 200-400 Da under relatively mild conditions. Cl(-) could interact strongly with the end OH group of the glucose unit in a 1:1 ratio, which resulted in the enhanced breaking of both inter- and intramolecular hydrogen bonds. In particular, the intermolecular hydrogen bond with an FTIR band at approximately v=3200 cm(-1) was disrupted significantly by Cl(-) . The FTIR band for a hydrogen bond between hemicellulose and lignin might appear at v=1636 cm(-1) , whereas this bond could be almost totally broken under hydrothermal conditions at 220 °C.

  15. Phosphate solubilization and promotion of maize growth by Penicillium oxalicum P4 and Aspergillus niger P85 in a calcareous soil.

    PubMed

    Yin, Zhongwei; Shi, Fachao; Jiang, Hongmei; Roberts, Daniel P; Chen, Sanfeng; Fan, Bingquan

    2015-12-01

    Alternative tactics for improving phosphorus nutrition in crop production are needed in China and elsewhere, as the overapplication of phosphatic fertilizers can adversely impact agricultural sustainability. Penicillium oxalicum P4 and Aspergillus niger P85 were isolated from a calcareous soil in China that had been exposed to excessive application of phosphatic fertilizer for decades. Each isolate excreted a number of organic acids into, acidified, and solubilized phosphorus in a synthetic broth containing insoluble tricalcium phosphate or rock phosphate. Isolate P4, applied as a seed treatment, increased maize fresh mass per plant when rock phosphate was added to the calcareous soil in greenhouse pot studies. Isolate P85 did not increase maize fresh mass per plant but did significantly increase total phosphorus per plant when rock phosphate was added. Significant increases in 7 and 4 organic acids were detected in soil in association with isolates P4 and P85, respectively, relative to the soil-only control. The quantity and (or) number of organic acids produced by these isolates increased when rock phosphate was added to the soil. Both isolates also significantly increased available phosphorus in soil in the presence of added rock phosphate and effectively colonized the maize rhizosphere. Studies reported here indicate that isolate P4 is adapted to and capable of promoting maize growth in a calcareous soil. Plant-growth promotion by this isolate is likely due, at least in part, to increased phosphorus availability resulting from the excretion of organic acids into, and the resulting acidification of, this soil.

  16. Promoting Uranium Immobilization by the Activities of Microbial Phosphatases

    SciTech Connect

    Martinez, Robert J.; Beazley, Melanie J.; Wilson, Jarad J.; Taillefert, Martial; Sobecky, Patricia A.

    2005-04-05

    The overall goal of this project is to examine the role of nonspecific phosphohydrolases present in naturally occurring subsurface microorganisms for the purpose of promoting the immobilization of radionuclides through the production of uranium [U(VI)] phosphate precipitates. Specifically, we hypothesize that the precipitation of U(VI) phosphate minerals may be promoted through the microbial release and/or accumulation of PO{sub 4}{sup 3-}. During this phase of the project we have been conducting assays to determine the effects of pH, inorganic anions and organic ligands on U(VI) mineral formation and precipitation when FRC bacterial isolates were grown in simulated groundwater medium. The molecular characterization of FRC isolates has also been undertaken during this phase of the project. Analysis of a subset of gram-positive FRC isolates cultured from FRC soils (Areas 1, 2 and 3) and background sediments have indicated a higher percentage of isolates exhibiting phosphatase phenotypes (i.e., in particular those surmised to be PO{sub 4}{sup 3-}-irrepressible) relative to isolates from the reference site. A high percentage of strains that exhibited such putatively PO{sub 4}{sup 3-}-irrepressible phosphatase phenotypes were also resistant to the heavy metals lead and cadmium. Previous work on FRC strains, including Arthrobacter, Bacillus and Rahnella spp., has demonstrated differences in tolerance to U(VI) toxicity (200 {micro}M) in the absence of organophosphate substrates. For example, Arthrobacter spp. exhibited the greatest tolerance to U(VI) while the Rahnella spp. have been shown to facilitate the precipitation of U(VI) from solution and the Bacillus spp. demonstrate the greatest sensitivity to acidic conditions and high concentrations of U(VI). PCR-based detection of FRC strains are being conducted to determine if non-specific acid phosphatases of the known molecular classes [i.e., classes A, B and C] are present in these FRC isolates. Additionally, these

  17. Promoting Uranium Immobilization by the Activities of Microbial Phosphatases

    SciTech Connect

    Robert J. Martinez; Melanie J. Beazley; Samuel M. Webb; Martial Taillefert; and Patricia A. Sobecky

    2007-04-19

    The overall objective of this project is to examine the activity of nonspecific phosphohydrolases present in naturally occurring subsurface microorganisms for the purpose of promoting the immobilization of radionuclides through the production of uranium [U(VI)] phosphate precipitates. Specifically, we hypothesize that the precipitation of U(VI) phosphate minerals may be promoted through the microbial release and/or accumulation of PO4 3- as a means to detoxify radionuclides and heavy metals. An experimental approach was designed to determine the extent of phosphatase activity in bacteria previously isolated from contaminated subsurface soils collected at the ERSP Field Research Center (FRC) in Oak Ridge, TN. Screening of 135 metal resistant isolates for phosphatase activity indicated the majority (75 of 135) exhibited a phosphatase-positive phenotype. During this phase of the project, a PCR based approach has also been designed to assay FRC isolates for the presence of one or more classes of the characterized non-specific acid phophastase (NSAP) genes likely to be involved in promoting U(VI) precipitation. Testing of a subset of Pb resistant (Pbr) Arthrobacter, Bacillus and Rahnella strains indicated 4 of the 9 Pbr isolates exhibited phosphatase phenotypes suggestive of the ability to bioprecipitate U(VI). Two FRC strains, a Rahnella sp. strain Y9602 and a Bacillus sp. strain Y9-2, were further characterized. The Rahnella sp. exhibited enhanced phosphatase activity relative to the Bacillus sp. Whole-cell enzyme assays identified a pH optimum of 5.5, and inorganic phosphate accumulated in pH 5.5 synthetic groundwater (designed to mimic FRC conditions) incubations of both strains in the presence of a model organophosphorus substrate provided as the sole C and P source. Kinetic experiments showed that these two organisms can grow in the presence of 200 μM dissolved uranium and that Rahnella is much more efficient in precipitating U(VI) than Bacillus sp. The

  18. Role of phosphate solubilizing Burkholderia spp. for successful colonization and growth promotion of Lycopodium cernuum L. (Lycopodiaceae) in lateritic belt of Birbhum district of West Bengal, India.

    PubMed

    Ghosh, Ranjan; Barman, Soma; Mukherjee, Rajib; Mandal, Narayan C

    2016-02-01

    Profuse growth of Lycpodium cernuum L. was found in phosphate deficient red lateritic soil of West Bengal, India. Interaction of vesicular-arbuscular mycorrhiza (VAM) with Lycopodium rhizoids were described earlier but association of PGPR with their rhizoids were not studied. Three potent phosphate solubilizing bacterial strains (P4, P9 and P10) associated with L. cernuum rhizoids were isolated and identified by 16S rDNA homologies on Ez-Taxon database as Burkholderia tropica, Burkholderia unamae and Burkholderia cepacia respectively. Day wise kinetics of phosphate solubilization against Ca3(PO4)2 suggested P4 (580.56±13.38 μg ml(-1)) as maximum mineral phosphate solubilizer followed by P9 (517.12±17.15 μg ml(-1)) and P10 (485.18±14.23 μg ml(-1)) at 28 °C. Release of bound phosphates by isolated strains from ferric phosphate (FePO4), aluminum phosphate (AlPO4) and four different complex rock phosphates indicated their very good phosphate solubilizng efficacy. Nitrogen independent solubilizition also supports their nitrogen fixing capabilities. Inhibition of P solubilization by calcium salts and induction by EDTA suggested pH dependent chelation of metal cations by all of the isolates. Rhizoidal colonization potentials of Burkholderia spp. were confirmed by in planta experiment and also using scanning electron microscope (SEM). Increases of total phosphate content in Lycopodium plants upon soil treatment with these isolates were also recorded. In addition siderophore production on CAS agar medium, tryptophan dependent IAA production and antifungal activities against pathogenic fungi by rhizospheric isolates deep-rooted that they have definite role in nutrient mobilization for successful colonization of L. cernuum in nutrient deficient lateritic soil.

  19. Microbial recovery of metals from spent coal liquefaction catalysts. Final and quarterly report, July 1994--September 1994

    SciTech Connect

    Sandbeck, K.A.; Cleveland, D.

    1995-08-01

    Research is reported on the recovery of molybdenum and nickel from spent coal liquefaction catalysts. Mo release from spent coal liquefaction catalysts has been shown to be dependent upon many parameters, but release is dominated by microbial growth. The microbial Mo release is a rapid process requiring less than one week for 90% of the releaseable Mo to be solubilized from whole washed (THF) catalyst. It could be expected that the rates would be even greater with crushed catalyst. Efforts were centered on optimizing the parameters that stimulate microbial growth and action and further efforts centered on catalyst pre-treatment prior to microbial bio-leaching. Recent experiments suggest that hydrogen peroxide promises to be an effective pre-treatment wash. Hydrogen peroxide was also found to be an effective and economical agent for metals solubilization per se and could promote solubilization without subjecting the catalyst to microbial growth.

  20. Research and engineering assessment of biological solubilization of phosphate

    SciTech Connect

    Rogers, R.D.; McIlwain, M.E.; Losinski, S.J.; Taylor, D.D.

    1993-03-01

    This research and engineering assessment examined a microbial phosphate solubilization process as a method of recovering phosphate from phosphorus containing ore compared to the existing wet acid and electric arc methods. A total of 860 microbial isolates, collected from a range of natural environments were tested for their ability to solubilize phosphate from rock phosphate. A bacterium (Pseudomonas cepacia) was selected for extensive characterization and evaluation of the mechanism of phosphate solubilization and of process engineering parameters necessary to recover phosphate from rock phosphate. These studies found that concentration of hydrogen ion and production of organic acids arising from oxidation of the carbon source facilitated microbial solubilization of both pure chemical insoluble phosphate compounds and phosphate rock. Genetic studies found that phosphate solubilization was linked to an enzyme system (glucose dehydrogenase). Process-related studies found that a critical solids density of 1% by weight (ore to liquid) was necessary for optimal solubilization. An engineering analysis evaluated the cost and energy requirements for a 2 million ton per year sized plant, whose size was selected to be comparable to existing wet acid plants.

  1. Microbial exudate promoted dissolution and transformation of chromium containing minerals

    NASA Astrophysics Data System (ADS)

    Saad, E. M.; Sun, J.; Tang, Y.

    2015-12-01

    Because of its utility in many industrial processes, chromium has become the second most common metal contaminant in the United States. The two most common oxidation states of chromium in nature are Cr(III), which is highly immobile, and Cr(VI), which is highly mobile and toxic. In both natural and engineered environments, the most common remediation of Cr(VI) is through reduction, which results in chromium sequestration in the low solubility mixed Cr(III)-Fe(III) (oxy)hydroxide phases. Consequently, the stability of these minerals must be examined to assess the fate of chromium in the subsurface. We examined the dissolution of mixed Cr(III)-Fe(III) (oxy)hydroxides in the presence of common microbial exudates, including the siderophore desferrioxamine B (DFOB; a common organic ligand secreted by most microbes with high affinity for ferric iron and other trivalent metal ions) and oxalate (a common organic acid produced by microbes). The solids exhibited incongruent dissolution with preferential leaching of Fe from the solid phase. Over time, this leads to a more Cr rich mineral, which is known to be more soluble than the corresponding mixed mineral phase. We are currently investigating the structure of the reacted mineral phases and soluble Cr(III) species, as well as the potential oxidation and remobilization of the soluble Cr species. Results from this study will provide insights regarding the long term transport and fate of chromium in the natural environment in the presence of microbial activities.

  2. Promoting uranium immobilization by the activities of microbial phophatases

    SciTech Connect

    Sobecky, Patricia A.

    2005-06-01

    The first objective of this project is to determine the relationship of phosphatase activity to metal resistance in subsurface strains and the role of lateral gene transfer (LGT) in dissemination of nonspecific acid phosphatase genes. Nonspecific acid phosphohydrolases are a broad group of secreted microbial phosphatases that function in acidic-to-neutral pH ranges and utilize a wide range of organophosphate substrates. We have previously shown that PO43- accumulation during growth on a model organophosphorus compound was attributable to the overproduction of alkaline phosphatase by genetically modified subsurface pseudomonads [Powers et al. (2002) FEMS Microbiol. Ecol. 41:115-123]. During this report period, we have extended these results to include indigenous metal resistant subsurface microorganisms cultivated from the Field Research Center (FRC), in Oak Ridge Tennessee.

  3. Inhibition of Aspergillus niger phosphate solubilization by fluoride released from rock phosphate.

    PubMed

    Mendes, Gilberto de Oliveira; Vassilev, Nikolay Bojkov; Bonduki, Victor Hugo Araújo; da Silva, Ivo Ribeiro; Ribeiro, José Ivo; Costa, Maurício Dutra

    2013-08-01

    The simultaneous release of various chemical elements with inhibitory potential for phosphate solubilization from rock phosphate (RP) was studied in this work. Al, B, Ba, Ca, F, Fe, Mn, Mo, Na, Ni, Pb, Rb, Si, Sr, V, Zn, and Zr were released concomitantly with P during the solubilization of Araxá RP (Brazil), but only F showed inhibitory effects on the process at the concentrations detected in the growth medium. Besides P solubilization, fluoride decreased fungal growth, citric acid production, and medium acidification by Aspergillus niger. At the maximum concentration found during Araxá RP solubilization (22.9 mg F(-) per liter), fluoride decreased P solubilization by 55%. These findings show that fluoride negatively affects RP solubilization by A. niger through its inhibitory action on the fungal metabolism. Given that fluoride is a common component of RPs, the data presented here suggest that most of the microbial RP solubilization systems studied so far were probably operated under suboptimal conditions.

  4. Isolation of phosphate-solubilizing fungus and its application in solubilization of rock phosphates.

    PubMed

    Wu, Yingben; He, Yuelin; Yin, Hongmei; Chen, Wei; Wang, Zhen; Xu, Lijuan; Zhang, Aiqun

    2012-12-01

    Microorganisms have been obtained to improve the agronomic value of rock phosphates (RPs), but the phosphorus solubilizing rate by these approaches is very slow. It is important to explore a high-efficient phosphate-solubilizing approach with a kind of microorganisms. This study aimed to isolate a high-efficient level of phosphate-solubilizing fungus from rhizosphere soil samples phosphate mines (Liuyang County, Hunan province, China) and apply it in solubilization of RPs. The experiments were carried out by the conventional methodology for morphological and biochemical fungus characterization and the analysis of 18s rRNA sequence. Then the effects of time, temperature, initial pH, phosphorus (P) sources, RPs concentration, shaking speed and silver ion on the content of soluble P released by this isolate were investigated. The results showed this isolate was identified as Galactomyces geotrichum P14 (P14) in GeneBank and the maximum amount of soluble P was 1252.13 mg L(-1) within 40 h in a modified phosphate growth agar's medium (without agar) where contained tricalcium phosphate (TCP) as sole phosphate source. At the same time, it could release phosphate and solubilize various rock phosphates. The isolated fungus can convert RPs from insoluble form into plant available form and therefore it hold great potential for biofertilizers to enhance soil fertility and promote plant growth.

  5. Biological management of Sclerotinia sclerotiorum in pea using plant growth promoting microbial consortium.

    PubMed

    Jain, Akansha; Singh, Akanksha; Singh, Surendra; Singh, Harikesh Bahadur

    2015-08-01

    The beneficial plant-microbe interactions play crucial roles in protection against large number of plant pathogens causing disease. The present study aims to investigate the growth promoting traits induced by beneficial microbes namely Pseudomonas aeruginosa PJHU15, Trichoderma harzianum TNHU27, and Bacillus subtilis BHHU100 treated singly and in combinations under greenhouse and field conditions to control Sclerotinia sclerotiorum. Plants treated with three microbe consortium enhanced plant growth maximally both in the presence and absence of the pathogen. Increase in plant length, total biomass, number of leaves, nodules and secondary roots, total chlorophyll and carotenoid content, and yield were recorded in plants treated with microbial consortia. Also, a decrease in plant mortality was observed in plants treated with microbial consortia in comparison to untreated control plants challenged with S. sclerotiorum. Furthermore, the decrease in disease of all the treatments can be associated with differential improvement of growth induced in pea.

  6. Biomineralization of U(VI) phosphate promoted by microbially-mediated phytate hydrolysis in contaminated soils

    NASA Astrophysics Data System (ADS)

    Salome, Kathleen R.; Beazley, Melanie J.; Webb, Samuel M.; Sobecky, Patricia A.; Taillefert, Martial

    2017-01-01

    The bioreduction of uranium may immobilize a significant fraction of this toxic contaminant in reduced environments at circumneutral pH. In oxic and low pH environments, however, the low solubility of U(VI)-phosphate minerals also makes them good candidates for the immobilization of U(VI) in the solid phase. As inorganic phosphate is generally scarce in soils, the biomineralization of U(VI)-phosphate minerals via microbially-mediated organophosphate hydrolysis may represent the main immobilization process of uranium in these environments. In this study, contaminated sediments were incubated aerobically in two pH conditions to examine whether phytate, a naturally-occurring and abundant organophosphate in soils, could represent a potential phosphorous source to promote U(VI)-phosphate biomineralization by natural microbial communities. While phytate hydrolysis was not evident at pH 7.0, nearly complete hydrolysis was observed both with and without electron donor at pH 5.5, suggesting indigenous microorganisms express acidic phytases in these sediments. While the rate of hydrolysis of phytate generally increased in the presence of uranium, the net rate of inorganic phosphate production in solution was decreased and inositol phosphate intermediates were generated in contrast to similar incubations conducted without uranium. These findings suggest uranium stress enhanced the phytate-metabolism of the microbial community, while simultaneously inhibiting phosphatase production and/or activity by the indigenous population. Finally, phytate hydrolysis drastically decreased uranium solubility, likely due to formation of ternary sorption complexes, U(VI)-phytate precipitates, and U(VI)-phosphate minerals. Overall, the results of this study provide evidence for the ability of natural microbial communities to liberate phosphate from phytate in acidic sediments, possibly as a detoxification mechanism, and demonstrate the potential utility of phytate-promoted uranium

  7. Biochar enhances Aspergillus niger rock phosphate solubilization by increasing organic acid production and alleviating fluoride toxicity.

    PubMed

    Mendes, Gilberto de Oliveira; Zafra, David Lopez; Vassilev, Nikolay Bojkov; Silva, Ivo Ribeiro; Ribeiro, José Ivo; Costa, Maurício Dutra

    2014-05-01

    During fungal rock phosphate (RP) solubilization, a significant quantity of fluoride (F(-)) is released together with phosphorus (P), strongly inhibiting the process. In the present study, the effect of two F(-) adsorbents [activated alumina (Al2O3) and biochar] on RP solubilization by Aspergillus niger was examined. Al2O3 adsorbed part of the F(-) released but also adsorbed soluble P, which makes it inappropriate for microbial RP solubilization systems. In contrast, biochar adsorbed only F(-) while enhancing phosphate solubilization 3-fold, leading to the accumulation of up to 160 mg of P per liter. By comparing the values of F(-) measured in solution at the end of incubation and those from a predictive model, it was estimated that up to 19 mg of F(-) per liter can be removed from solution by biochar when added at 3 g liter(-1) to the culture medium. Thus, biochar acted as an F(-) sink during RP solubilization and led to an F(-) concentration in solution that was less inhibitory to the process. In the presence of biochar, A. niger produced larger amounts of citric, gluconic, and oxalic acids, whether RP was present or not. Our results show that biochar enhances RP solubilization through two interrelated processes: partial removal of the released F(-) and increased organic acid production. Given the importance of organic acids for P solubilization and that most of the RPs contain high concentrations of F(-), the proposed solubilization system offers an important technological improvement for the microbial production of soluble P fertilizers from RP.

  8. Solubilized xenon 133 lung scintigraphy

    SciTech Connect

    Oates, E.; Sarno, R.C.

    1988-11-01

    Lung scanning using solubilized xenon 133 can provide important information concerning both pulmonary perfusion and ventilation. This technique proved valuable in establishing the diagnosis of congenital lobar emphysema in a 7-month-old baby.

  9. Potential of wheat bran to promote indigenous microbial enhanced oil recovery.

    PubMed

    Zhan, Yali; Wang, Qinghong; Chen, Chunmao; Kim, Jung Bong; Zhang, Hongdan; Yoza, Brandon A; Li, Qing X

    2017-02-11

    Microbial enhanced oil recovery (MEOR) is an emerging oil extraction technology that utilizes microorganisms to facilitate recovery of crude oil in depleted petroleum reservoirs. In the present study, effects of wheat bran utilization were investigated on stimulation of indigenous MEOR. Biostimulation conditions were optimized with the response surface methodology. The co-application of wheat bran with KNO3 and NH4H2PO4 significantly promoted indigenous MEOR (IMEOR) and exhibited sequential aerobic (O-), facultative (An-) and anaerobic (A0-) metabolic stages. The surface tension of fermented broth decreased by approximately 35%, and the crude oil was highly emulsified. Microbial community structure varied largely among and in different IMEOR metabolic stages. Pseudomonas sp., Citrobacter sp., and uncultured Burkholderia sp. dominated the O-, An- and early A0-stages. Bacillus sp., Achromobacter sp., Rhizobiales sp., Alcaligenes sp. and Clostridium sp. dominated the later A0-stage. This study illustrated occurrences of microbial community succession driven by wheat bran stimulation and its industrial potential.

  10. Microbial shifts in the swine distal gut in response to the treatment with antimicrobial growth promoter, tylosin.

    PubMed

    Kim, Hyeun Bum; Borewicz, Klaudyna; White, Bryan A; Singer, Randall S; Sreevatsan, Srinand; Tu, Zheng Jin; Isaacson, Richard E

    2012-09-18

    Antimicrobials have been used extensively as growth promoters (AGPs) in agricultural animal production. However, the specific mechanism of action for AGPs has not yet been determined. The work presented here was to determine and characterize the microbiome of pigs receiving one AGP, tylosin, compared with untreated pigs. We hypothesized that AGPs exerted their growth promoting effect by altering gut microbial population composition. We determined the fecal microbiome of pigs receiving tylosin compared with untreated pigs using pyrosequencing of 16S rRNA gene libraries. The data showed microbial population shifts representing both microbial succession and changes in response to the use of tylosin. Quantitative and qualitative analyses of sequences showed that tylosin caused microbial population shifts in both abundant and less abundant species. Our results established a baseline upon which mechanisms of AGPs in regulation of health and growth of animals can be investigated. Furthermore, the data will aid in the identification of alternative strategies to improve animal health and consequently production.

  11. Effect of heavy metal-solubilizing microorganisms on zinc and cadmium extractions from heavy metal contaminated soil with Tricholoma lobynsis.

    PubMed

    Ji, Ling-yun; Zhang, Wei-wei; Yu, Dong; Cao, Yan-ru; Xu, Heng

    2012-01-01

    The macrofungus, Tricholoma lobynsis, was chosen to remedy Zn-Cd-Pb contaminated soil. To enhance its metal-extracting efficiency, two heavy metal resistant microbes M6 and K1 were applied owing to their excellent abilities to solubilize heavy metal salts. The two isolated microbial strains could also produce indole acetic acid (IAA), siderophore and solubilize inorganic phosphate, but neither of them showed 1-aminocyclopropane-1-carboxylate deaminase activity. The strains M6 and K1 were identified as Serratia marcescens and Rhodotorula mucilaginosa based on 16S rDNA and ITS sequence analysis respectively. Pot experiment showed that spraying to T. lobynsis-inoculated soil with M6 and K1 respectively could increase total Cd accumulations of this mushroom by 216 and 61%, and Zn by 153 and 49% compared to the uninoculated control. Pb accumulation however, was too low (<1 mg kg(-1)) to be determined. The results illustrated that special microbes and macrofungi can work together to remedy polluted soil as plant and plant growth promoting microbes do, probably because of excellent metal-accumulating abilities of macrofungi and IAA-siderophore production, phosphate solubilization abilities of the assisted-microbes. This kind of macrofungi-microbe interaction can be developed into a novel bioremediation strategy.

  12. Fluoride-tolerant mutants of Aspergillus niger show enhanced phosphate solubilization capacity.

    PubMed

    Silva, Ubiana de Cássia; Mendes, Gilberto de Oliveira; Silva, Nina Morena R M; Duarte, Josiane Leal; Silva, Ivo Ribeiro; Tótola, Marcos Rogério; Costa, Maurício Dutra

    2014-01-01

    P-solubilizing microorganisms are a promising alternative for a sustainable use of P against a backdrop of depletion of high-grade rock phosphates (RPs). Nevertheless, toxic elements present in RPs, such as fluorine, can negatively affect microbial solubilization. Thus, this study aimed at selecting Aspergillus niger mutants efficient at P solubilization in the presence of fluoride (F-). The mutants were obtained by exposition of conidia to UV light followed by screening in a medium supplemented with Ca3(PO4)2 and F-. The mutant FS1-555 showed the highest solubilization in the presence of F-, releasing approximately 70% of the P contained in Ca3(PO4)2, a value 1.7 times higher than that obtained for the wild type (WT). The mutant FS1-331 showed improved ability of solubilizing fluorapatites, increasing the solubilization of Araxá, Catalão, and Patos RPs by 1.7, 1.6, and 2.5 times that of the WT, respectively. These mutants also grew better in the presence of F-, indicating that mutagenesis allowed the acquisition of F- tolerance. Higher production of oxalic acid by FS1-331 correlated with its improved capacity for RP solubilization. This mutant represents a significant improvement and possess a high potential for application in solubilization systems with fluoride-rich phosphate sources.

  13. Fluoride-Tolerant Mutants of Aspergillus niger Show Enhanced Phosphate Solubilization Capacity

    PubMed Central

    Silva, Ubiana de Cássia; Mendes, Gilberto de Oliveira; Silva, Nina Morena R. M.; Duarte, Josiane Leal; Silva, Ivo Ribeiro; Tótola, Marcos Rogério; Costa, Maurício Dutra

    2014-01-01

    P-solubilizing microorganisms are a promising alternative for a sustainable use of P against a backdrop of depletion of high-grade rock phosphates (RPs). Nevertheless, toxic elements present in RPs, such as fluorine, can negatively affect microbial solubilization. Thus, this study aimed at selecting Aspergillus niger mutants efficient at P solubilization in the presence of fluoride (F−). The mutants were obtained by exposition of conidia to UV light followed by screening in a medium supplemented with Ca3(PO4)2 and F−. The mutant FS1-555 showed the highest solubilization in the presence of F−, releasing approximately 70% of the P contained in Ca3(PO4)2, a value 1.7 times higher than that obtained for the wild type (WT). The mutant FS1-331 showed improved ability of solubilizing fluorapatites, increasing the solubilization of Araxá, Catalão, and Patos RPs by 1.7, 1.6, and 2.5 times that of the WT, respectively. These mutants also grew better in the presence of F−, indicating that mutagenesis allowed the acquisition of F− tolerance. Higher production of oxalic acid by FS1-331 correlated with its improved capacity for RP solubilization. This mutant represents a significant improvement and possess a high potential for application in solubilization systems with fluoride-rich phosphate sources. PMID:25310310

  14. Is artificial recharge promoting microbial activity and biodegradation processes in groundwater systems?

    NASA Astrophysics Data System (ADS)

    Barba Ferrer, Carme; Folch, Albert; Gaju, Núria; Martínez-Alonso, Maira; Carrasquilla, Marc; Grau-Martínez, Alba; Sanchez-Vila, Xavier

    2016-04-01

    Managed Artificial Recharge (MAR) represents a strategic tool for managing water resources, especially during scarce periods. On one hand, it can increase water stored in aquifers and extract it when weather conditions do not permit exclusive exploitation of surface resources. On the other, it allows improve water quality due the processes occurring into the soil whereas water crosses vadose zone. Barcelona (Catalonia, Spain) conurbation is suffering significant quantitative and qualitative groundwater disturbances. For this reason, Sant Vicenç MAR system, constituted by a sedimentation and an infiltration pond, was constructed in 2009 as the strategic water management infrastructure. Compared with other MAR facilities, this infiltration pond has a reactive bed formed by organic compost and local material. The objective is to promote different redox states allowing more and different degradation of chemical compounds than regular MAR systems. In previous studies in the site, physical and hydrochemical parameters demonstrated that there was indeed a degradation of different pollutants. However, to go a step further understanding the different biogeochemical processes and the related degradation processes occurring in the system, we studied the existing microbial communities. So, molecular techniques were applied in water and soil samples in two different scenarios; the first one, when the system was fully operating and the second when the system was not operating during some months. We have specifically compared microbial diversity and richness indexes and both cluster dendrograms obtained from DGGEs analysis made in each sampling campaign.

  15. Increased plant productivity and decreased microbial respiratory C loss by plant growth-promoting rhizobacteria under elevated CO2

    NASA Astrophysics Data System (ADS)

    Nie, Ming; Bell, Colin; Wallenstein, Matthew D.; Pendall, Elise

    2015-03-01

    Increased plant productivity and decreased microbial respiratory C loss can potentially mitigate increasing atmospheric CO2, but we currently lack effective means to achieve these goals. Soil microbes may play critical roles in mediating plant productivity and soil C/N dynamics under future climate scenarios of elevated CO2 (eCO2) through optimizing functioning of the root-soil interface. By using a labeling technique with 13C and 15N, we examined the effects of plant growth-promoting Pseudomonas fluorescens on C and N cycling in the rhizosphere of a common grass species under eCO2. These microbial inoculants were shown to increase plant productivity. Although strong competition for N between the plant and soil microbes was observed, the plant can increase its capacity to store more biomass C per unit of N under P. fluorescens addition. Unlike eCO2 effects, P. fluorescens inoculants did not change mass-specific microbial respiration and accelerate soil decomposition related to N cycling, suggesting these microbial inoculants mitigated positive feedbacks of soil microbial decomposition to eCO2. The potential to mitigate climate change by optimizing soil microbial functioning by plant growth-promoting Pseudomonas fluorescens is a prospect for ecosystem management.

  16. Increased plant productivity and decreased microbial respiratory C loss by plant growth-promoting rhizobacteria under elevated CO₂.

    PubMed

    Nie, Ming; Bell, Colin; Wallenstein, Matthew D; Pendall, Elise

    2015-03-18

    Increased plant productivity and decreased microbial respiratory C loss can potentially mitigate increasing atmospheric CO₂, but we currently lack effective means to achieve these goals. Soil microbes may play critical roles in mediating plant productivity and soil C/N dynamics under future climate scenarios of elevated CO₂ (eCO₂) through optimizing functioning of the root-soil interface. By using a labeling technique with (13)C and (15)N, we examined the effects of plant growth-promoting Pseudomonas fluorescens on C and N cycling in the rhizosphere of a common grass species under eCO₂. These microbial inoculants were shown to increase plant productivity. Although strong competition for N between the plant and soil microbes was observed, the plant can increase its capacity to store more biomass C per unit of N under P. fluorescens addition. Unlike eCO₂ effects, P. fluorescens inoculants did not change mass-specific microbial respiration and accelerate soil decomposition related to N cycling, suggesting these microbial inoculants mitigated positive feedbacks of soil microbial decomposition to eCO₂. The potential to mitigate climate change by optimizing soil microbial functioning by plant growth-promoting Pseudomonas fluorescens is a prospect for ecosystem management.

  17. Increased plant productivity and decreased microbial respiratory C loss by plant growth-promoting rhizobacteria under elevated CO2

    PubMed Central

    Nie, Ming; Bell, Colin; Wallenstein, Matthew D.; Pendall, Elise

    2015-01-01

    Increased plant productivity and decreased microbial respiratory C loss can potentially mitigate increasing atmospheric CO2, but we currently lack effective means to achieve these goals. Soil microbes may play critical roles in mediating plant productivity and soil C/N dynamics under future climate scenarios of elevated CO2 (eCO2) through optimizing functioning of the root-soil interface. By using a labeling technique with 13C and 15N, we examined the effects of plant growth-promoting Pseudomonas fluorescens on C and N cycling in the rhizosphere of a common grass species under eCO2. These microbial inoculants were shown to increase plant productivity. Although strong competition for N between the plant and soil microbes was observed, the plant can increase its capacity to store more biomass C per unit of N under P. fluorescens addition. Unlike eCO2 effects, P. fluorescens inoculants did not change mass-specific microbial respiration and accelerate soil decomposition related to N cycling, suggesting these microbial inoculants mitigated positive feedbacks of soil microbial decomposition to eCO2. The potential to mitigate climate change by optimizing soil microbial functioning by plant growth-promoting Pseudomonas fluorescens is a prospect for ecosystem management. PMID:25784647

  18. Inhibition of Aspergillus niger Phosphate Solubilization by Fluoride Released from Rock Phosphate

    PubMed Central

    Mendes, Gilberto de Oliveira; Vassilev, Nikolay Bojkov; Bonduki, Victor Hugo Araújo; da Silva, Ivo Ribeiro; Ribeiro, José Ivo

    2013-01-01

    The simultaneous release of various chemical elements with inhibitory potential for phosphate solubilization from rock phosphate (RP) was studied in this work. Al, B, Ba, Ca, F, Fe, Mn, Mo, Na, Ni, Pb, Rb, Si, Sr, V, Zn, and Zr were released concomitantly with P during the solubilization of Araxá RP (Brazil), but only F showed inhibitory effects on the process at the concentrations detected in the growth medium. Besides P solubilization, fluoride decreased fungal growth, citric acid production, and medium acidification by Aspergillus niger. At the maximum concentration found during Araxá RP solubilization (22.9 mg F− per liter), fluoride decreased P solubilization by 55%. These findings show that fluoride negatively affects RP solubilization by A. niger through its inhibitory action on the fungal metabolism. Given that fluoride is a common component of RPs, the data presented here suggest that most of the microbial RP solubilization systems studied so far were probably operated under suboptimal conditions. PMID:23770895

  19. Microbial culture collections as pillars for promoting fungal diversity, conservation and exploitation.

    PubMed

    Sette, Lara Durães; Pagnocca, Fernando Carlos; Rodrigues, André

    2013-11-01

    Fungi are a diverse group of organisms with an overall global number of 1.5M up to 3.3M species on Earth. Besides their ecological roles as decomposers, fungi are important in several aspects of applied research. Here, we review how culture collections may promote the knowledge on diversity, conservation and biotechnological exploitation of fungi. The impact of fungi diversity on biotechnological studies is discussed. We point out the major roles of microbial repositories, including fungal preservation, prospecting, identification, authentication and supply. A survey on the World Data Center for Microorganisms (WDCM) powered by the World Federation for Culture Collections and on the Genetic Heritage Management Council (CGEN) database revealed that 46 Brazilian culture collections registered in these databases are dedicate to preserving fungi. Most of these culture collections are located in the Southeast of Brazil. This scenario also demonstrates that Brazil has many collections focused on fungal strains, but the lack of up-to-date information in WDCM as well as of a solid national platform for culture collections registration do not allow accurate assessment of fungal preservation.

  20. Linking the Belowground Microbial Composition, Diversity and Activity to Soilborne Disease Suppression and Growth Promotion of Tomato Amended with Biochar

    PubMed Central

    Jaiswal, Amit K.; Elad, Yigal; Paudel, Indira; Graber, Ellen R.; Cytryn, Eddie; Frenkel, Omer

    2017-01-01

    Biochar, in addition to sequestering carbon, ameliorating soil, and improving plant performance, can impact foliar and soilborne plant diseases. Nevertheless, the mechanisms associated with suppression of soilborne diseases and improved plant performances are not well understood. This study is designed to establish the relationships between biochar-induced changes in rhizosphere microbial community structure, taxonomic and functional diversity, and activity with soilborne disease suppression and enhanced plant performance in a comprehensive fashion. Biochar suppressed Fusarium crown and root-rot of tomato and simultaneously improved tomato plant growth and physiological parameters. Furthermore, biochar reduced Fusarium root colonization and survival in soil, and increased the culturable counts of several biocontrol and plant growth promoting microorganisms. Illumina sequencing analyses of 16S rRNA gene revealed substantial differences in rhizosphere bacterial taxonomical composition between biochar-amended and non-amended treatments. Moreover, biochar amendment caused a significant increase in microbial taxonomic and functional diversity, microbial activities and an overall shift in carbon-source utilization. High microbial taxonomic and functional diversity and activity in the rhizosphere has been previously associated with suppression of diseases caused by soilborne pathogens and with plant growth promotion, and may collectively explain the significant reduction of disease and improvement in plant performance observed in the presence of biochar. PMID:28287177

  1. Linking the Belowground Microbial Composition, Diversity and Activity to Soilborne Disease Suppression and Growth Promotion of Tomato Amended with Biochar.

    PubMed

    Jaiswal, Amit K; Elad, Yigal; Paudel, Indira; Graber, Ellen R; Cytryn, Eddie; Frenkel, Omer

    2017-03-13

    Biochar, in addition to sequestering carbon, ameliorating soil, and improving plant performance, can impact foliar and soilborne plant diseases. Nevertheless, the mechanisms associated with suppression of soilborne diseases and improved plant performances are not well understood. This study is designed to establish the relationships between biochar-induced changes in rhizosphere microbial community structure, taxonomic and functional diversity, and activity with soilborne disease suppression and enhanced plant performance in a comprehensive fashion. Biochar suppressed Fusarium crown and root-rot of tomato and simultaneously improved tomato plant growth and physiological parameters. Furthermore, biochar reduced Fusarium root colonization and survival in soil, and increased the culturable counts of several biocontrol and plant growth promoting microorganisms. Illumina sequencing analyses of 16S rRNA gene revealed substantial differences in rhizosphere bacterial taxonomical composition between biochar-amended and non-amended treatments. Moreover, biochar amendment caused a significant increase in microbial taxonomic and functional diversity, microbial activities and an overall shift in carbon-source utilization. High microbial taxonomic and functional diversity and activity in the rhizosphere has been previously associated with suppression of diseases caused by soilborne pathogens and with plant growth promotion, and may collectively explain the significant reduction of disease and improvement in plant performance observed in the presence of biochar.

  2. Desert Farming Benefits from Microbial Potential in Arid Soils and Promotes Diversity and Plant Health

    PubMed Central

    Köberl, Martina; Müller, Henry; Ramadan, Elshahat M.; Berg, Gabriele

    2011-01-01

    Background To convert deserts into arable, green landscapes is a global vision, and desert farming is a strong growing area of agriculture world-wide. However, its effect on diversity of soil microbial communities, which are responsible for important ecosystem services like plant health, is still not known. Methodology/Principal Findings We studied the impact of long-term agriculture on desert soil in one of the most prominent examples for organic desert farming in Sekem (Egypt). Using a polyphasic methodological approach to analyse microbial communities in soil as well as associated with cultivated plants, drastic effects caused by 30 years of agriculture were detected. Analysing bacterial fingerprints, we found statistically significant differences between agricultural and native desert soil of about 60%. A pyrosequencing-based analysis of the 16S rRNA gene regions showed higher diversity in agricultural than in desert soil (Shannon diversity indices: 11.21/7.90), and displayed structural differences. The proportion of Firmicutes in field soil was significantly higher (37%) than in the desert (11%). Bacillus and Paenibacillus play the key role: they represented 96% of the antagonists towards phytopathogens, and identical 16S rRNA sequences in the amplicon library and for isolates were detected. The proportion of antagonistic strains was doubled in field in comparison to desert soil (21.6%/12.4%); disease-suppressive bacteria were especially enriched in plant roots. On the opposite, several extremophilic bacterial groups, e.g., Acidimicrobium, Rubellimicrobium and Deinococcus-Thermus, disappeared from soil after agricultural use. The N-fixing Herbaspirillum group only occurred in desert soil. Soil bacterial communities were strongly driven by the a-biotic factors water supply and pH. Conclusions/Significance After long-term farming, a drastic shift in the bacterial communities in desert soil was observed. Bacterial communities in agricultural soil showed a higher

  3. A biomaterial composed of collagen and solubilized elastin enhances angiogenesis and elastic fiber formation without calcification.

    PubMed

    Daamen, Willeke F; Nillesen, Suzan T M; Wismans, Ronnie G; Reinhardt, Dieter P; Hafmans, Theo; Veerkamp, Jacques H; van Kuppevelt, Toin H

    2008-03-01

    Elastin is the prime protein in elastic tissues that contributes to elasticity of, for example, lung, aorta, and skin. Upon injury, elastic fibers are not readily replaced, which hampers tissue regeneration. Incorporation of solubilized elastin (hydrolyzed insoluble elastin fibers or elastin peptides) in biomaterials may improve regeneration, because solubilized elastin is able to promote proliferation as well as elastin synthesis. Porous biomaterials composed of highly purified collagen without and without elastin fibers or solubilized elastin were prepared by freezing and lyophilization. Solubilized elastin formed spherical structures that were incorporated in the collagenous part of the scaffolds and that persisted after chemical crosslinking of the scaffolds. Crosslinked scaffolds were subcutaneously implanted in young Sprague Dawley rats. Collagen-solubilized elastin and collagen scaffolds showed no calcification in this sensitive calcification model, in contrast to scaffolds containing elastin fibers. Collagen-solubilized elastin scaffolds also induced angiogenesis, as revealed by type IV collagen staining, and promoted elastic fiber synthesis, as shown with antibodies against rat elastin and fibrillin-1. It is concluded that scaffolds produced from collagen and solubilized elastin present a non-calcifying biomaterial with a capacity for soft-tissue regeneration, especially in relation to elastic fiber synthesis.

  4. Isolation and partial characterization of phosphate solubilizing bacteria isolated from soil and marine samples.

    PubMed

    Mujahid, Talat Yasmeen; Siddiqui, Khaizran; Ahmed, Rifat; Kazmi, Shahana U; Ahmed, Nuzhat

    2014-09-01

    In the present study the potential of indigenous bacterial isolates from soil rhizosphere and marine environment to promote plant growth was determined. Eight bacterial strains isolated from soil and marine samples were characterized for the phosphate solubilizing activity. Qualitative and quantitative estimation of phosphate solubilization is done. MIC of antibiotic and heavy metals were checked for these strains. Strains show a diverse pattern of antibiotic and heavy metals resistance.

  5. Fluidized-bed bioreactor process for the microbial solubiliztion of coal

    DOEpatents

    Scott, Charles D.; Strandberg, Gerald W.

    1989-01-01

    A fluidized-bed bioreactor system for the conversion of coal into microbially solubilized coal products. The fluidized-bed bioreactor continuously or periodically receives coal and bio-reactants and provides for the production of microbially solubilized coal products in an economical and efficient manner. An oxidation pretreatment process for rendering coal uniformly and more readily susceptible to microbial solubilization may be employed with the fluidized-bed bioreactor.

  6. MyD88 Adaptor-Dependent Microbial Sensing by Regulatory T Cells Promotes Mucosal Tolerance and Enforces Commensalism.

    PubMed

    Wang, Sen; Charbonnier, Louis-Marie; Noval Rivas, Magali; Georgiev, Peter; Li, Ning; Gerber, Georg; Bry, Lynn; Chatila, Talal A

    2015-08-18

    Commensal microbiota promote mucosal tolerance in part by engaging regulatory T (Treg) cells via Toll-like receptors (TLRs). We report that Treg-cell-specific deletion of the TLR adaptor MyD88 resulted in deficiency of intestinal Treg cells, a reciprocal increase in T helper 17 (Th17) cells and heightened interleukin-17 (IL-17)-dependent inflammation in experimental colitis. It also precipitated dysbiosis with overgrowth of segmented filamentous bacteria (SFB) and increased microbial loads in deep tissues. The Th17 cell dysregulation and bacterial dysbiosis were linked to impaired anti-microbial intestinal IgA responses, related to defective MyD88 adaptor- and Stat3 transcription factor-dependent T follicular regulatory and helper cell differentiation in the Peyer's patches. These findings establish an essential role for MyD88-dependent microbial sensing by Treg cells in enforcing mucosal tolerance and maintaining commensalism by promoting intestinal Treg cell formation and anti-commensal IgA responses.

  7. The Distribution of Solubilized Molecules among Micelles.

    ERIC Educational Resources Information Center

    Miller, Dennis J.

    1978-01-01

    Conflicting views have been put forward on the derivation of the distribution of solubilized molecules among micelles. This stems from failure to consider the arrangement of the solubilized molecules in the micelles. In the treatment presented enthalpy effects are ignored as they are not amenable to a simple general theory. (Author/BB)

  8. Analysis of the abilities of endophytic bacteria associated with banana tree roots to promote plant growth.

    PubMed

    Andrade, Leandro Fernandes; de Souza, Gleika Larisse Oliveira Dorasio; Nietsche, Silvia; Xavier, Adelica Aparecida; Costa, Marcia Regina; Cardoso, Acleide Maria Santos; Pereira, Marlon Cristian Toledo; Pereira, Débora Francine Gomes Silva

    2014-01-01

    A total of 40 endophytic bacterial isolates obtained from banana tree roots were characterized for their biotechnological potential for promoting banana tree growth. All isolates had at least one positive feature. Twenty isolates were likely diazotrophs and formed pellicles in nitrogen-free culture medium, and 67% of these isolates belonged to the genus Bacillus sp. The isolates EB-04, EB-169, EB-64, and EB-144 had N fixation abilities as measured by the Kjeldahl method and by an acetylene reduction activity assay. Among the 40 isolates, 37.5% were capable of solubilizing inorganic phosphate and the isolates EB-47 and EB-64 showed the highest solubilization capacity. The isolate EB-53 (Lysinibacillus sp.) had a high solubilization index, whereas 73% of the isolates had low solubilization indices. The synthesis of indole-3-acetic acid (IAA) in the presence of L-tryptophan was detected in 40% of the isolates. The isolate EB-40 (Bacillus sp.) produced the highest amount of IAA (47.88 μg/ml) in medium supplemented with L-tryptophan and was able to synthesize IAA in the absence of L-tryptophan. The isolates EB-126 (Bacillus subtilis) and EB-47 (Bacillus sp.) were able to simultaneously fix nitrogen, solubilize phosphate and produce IAA in vitro. The results of this study demonstrated that the isolates analyzed here had diverse abilities and all have the potential to be used as growth-promoting microbial inoculants for banana trees.

  9. In situ stable isotope probing of phosphate-solubilizing bacteria in the hyphosphere

    PubMed Central

    Wang, Fei; Shi, Ning; Jiang, Rongfeng; Zhang, Fusuo; Feng, Gu

    2016-01-01

    This study used a [13C]DNA stable isotope probing (SIP) technique to elucidate a direct pathway for the translocation of 13C-labeled photoassimilate from maize plants to extraradical mycelium-associated phosphate-solubilizing bacteria (PSB) that mediate the mineralization and turnover of soil organic phosphorus (P) in the hyphosphere. Inoculation with PSB alone did not provide any benefit to maize plants but utilized the added phytate-P to their own advantage, while inoculation with Rhizophagus irregularis alone significantly promoted shoot biomass and P content compared with the control. However, compared with both sole inoculation treatments, combined inoculation with PSB and R. irregularis in the hyphosphere enhanced organic P mineralization and increased microbial biomass P in the soil. There was no extra benefit to plant P uptake but the hyphal growth of R. irregularis was reduced, suggesting that PSB benefited from the arbuscular mycorrhizal (AM) fungal mycelium and competed for soil P with the fungus. The combination of T-RFLP (terminal restriction fragment length polymorphism) analysis with a clone library revealed that one of the bacteria that actively assimilated carbon derived from pulse-labeled maize plants was Pseudomonas alcaligenes (Pseudomonadaceae) that was initially inoculated into the hyphosphere soil. These results provide the first in situ demonstration of the pathway underlying the carbon flux from plants to the AM mycelium-associated PSB, and the PSB assimilated the photosynthates exuded by the fungus and promoted mineralization and turnover of organic P in the soil. PMID:26802172

  10. Maize endophytic bacteria as mineral phosphate solubilizers.

    PubMed

    de Abreu, C S; Figueiredo, J E F; Oliveira, C A; Dos Santos, V L; Gomes, E A; Ribeiro, V P; Barros, B A; Lana, U G P; Marriel, I E

    2017-02-16

    In the present study, we demonstrated the in vitro activity of endophytic phosphate-solubilizing bacteria (PSB). Fifty-five endophytic PSB that were isolated from sap, leaves, and roots of maize were tested for their ability to solubilize tricalcium phosphate and produce organic acid. Partial sequencing of the 16S rRNA-encoding gene showed that the isolates were from the genus Bacillus and different species of Enterobacteriaceae. The phosphate solubilization index on solid medium and phosphate solubilization in liquid medium varied significantly among the isolates. There was a statistically significant difference (P ≤ 0.05) for both, the values of phosphate-solubilizing activity and pH of the growth medium, among the isolates. Pearson correlation was statistically significant (P ≤ 0.05) between P-solubilization and pH (R = -0.38), and between the gluconic acid production and the lowering of the pH of the liquid medium at 6 (R = 0.28) and 9 days (R = 0.39). Gluconic acid production was prevalent in all the PSB studied, and Bacillus species were most efficient in solubilizing phosphate. This is the first report on the characterization of bacterial endophytes from maize and their use as potential biofertilizers. In addition, this may provide an alternative strategy for improving the phosphorus acquisition efficiency of crop plants in tropical soils.

  11. High-melting lipid mixtures and the origin of detergent-resistant membranes studied with temperature-solubilization diagrams.

    PubMed

    Sot, Jesús; Manni, Marco M; Viguera, Ana R; Castañeda, Verónica; Cano, Ainara; Alonso, Cristina; Gil, David; Valle, Mikel; Alonso, Alicia; Goñi, Félix M

    2014-12-16

    The origin of resistance to detergent solubilization in certain membranes, or membrane components, is not clearly understood. We have studied the solubilization by Triton X-100 of binary mixtures composed of egg sphingomyelin (SM) and either ceramide, diacylglycerol, or cholesterol. Solubilization has been assayed in the 4-50°C range, and the results are summarized in a novel, to our knowledge, form of plots, that we have called temperature-solubilization diagrams. Despite using a large detergent excess (lipid/detergent 1:20 mol ratio) and extended solubilization times (24-48 h) certain mixtures were not amenable to Triton X-100 solubilization at one or more temperatures. DSC of all the lipid mixtures, and of all the lipid + detergent mixtures revealed that detergent resistance was associated with the presence of gel domains at the assay temperature. Once the system melted down, solubilization could occur. In general adding high-melting lipids limited the solubilization, whereas the addition of low-melting lipids promoted it. Lipidomic analysis of Madin-Darby canine kidney cell membranes and of the corresponding detergent-resistant fraction indicated a large enrichment of the nonsolubilized components in saturated diacylglycerol and ceramide. SM-cholesterol mixtures were special in that detergent solubilization was accompanied, for certain temperatures and compositions, by an independent phenomenon of reassembly of the partially solubilized lipid bilayers. The temperature at which lysis and reassembly prevailed was ∼25°C, thus for some SM-cholesterol mixtures solubilization occurred both above and below 25°C, but not at that temperature. These observations can be at the origin of the detergent resistance effects observed with cell membranes, and they also mean that cholesterol-containing detergent-resistant membrane remnants cannot correspond to structures existing in the native membrane before detergent addition.

  12. Mobilization and micellar solubilization of NAPL contaminants in aquifer rocks

    NASA Astrophysics Data System (ADS)

    Javanbakht, Gina; Goual, Lamia

    2016-02-01

    Surfactant-enhanced aquifer remediation is often performed to overcome the capillary forces that keep residual NAPL phases trapped within contaminated aquifers. The surfactant selection and displacement mechanism usually depend on the nature of NAPL constituents. For example, micellar solubilization is often used to cleanup DNAPLs from aquifers whereas mobilization is desirable in aquifers contaminated by LNAPLs. Although the majority of crude oils are LNAPLs, they often contain heavy organic macromolecules such as asphaltenes that are classified as DNAPLs. Asphaltenes contain surface-active components that tend to adsorb on rocks, altering their wettability. Previous studies revealed that surfactants that formed Winsor type III microemulsions could promote both mobilization and solubilization. However the extent by which these two mechanisms occur is still unclear, particularly in oil-contaminated aquifers. In this study we investigated the remediation of oil-contaminated aquifers using an environmentally friendly surfactant such as n-Dodecyl β-D-maltoside. Focus was given on asphaltenes to better understand the mechanisms of surfactant cleanup. Through phase behavior, spontaneous imbibition, dynamic interfacial tension and contact angle measurements, we showed that microemulsions formed by this surfactant are able to mobilize bulk NAPL (containing 9 wt.% asphaltenes) in the porous rock and solubilize DNAPL (i.e., 4-6 wt.% adsorbed asphaltenes) from the rock surface. Spontaneous imbibition tests, in particular, indicated that the ratio of mobilized to solubilized NAPL is about 6:1. Furthermore, aging the cores in NAPL beyond 3 days allowed for more NAPL to be trapped in the large pores of the rock but did not alter the amount of asphaltenes adsorbed on the mineral surface.

  13. Mobilization and micellar solubilization of NAPL contaminants in aquifer rocks.

    PubMed

    Javanbakht, Gina; Goual, Lamia

    2016-01-01

    Surfactant-enhanced aquifer remediation is often performed to overcome the capillary forces that keep residual NAPL phases trapped within contaminated aquifers. The surfactant selection and displacement mechanism usually depend on the nature of NAPL constituents. For example, micellar solubilization is often used to cleanup DNAPLs from aquifers whereas mobilization is desirable in aquifers contaminated by LNAPLs. Although the majority of crude oils are LNAPLs, they often contain heavy organic macromolecules such as asphaltenes that are classified as DNAPLs. Asphaltenes contain surface-active components that tend to adsorb on rocks, altering their wettability. Previous studies revealed that surfactants that formed Winsor type III microemulsions could promote both mobilization and solubilization. However the extent by which these two mechanisms occur is still unclear, particularly in oil-contaminated aquifers. In this study we investigated the remediation of oil-contaminated aquifers using an environmentally friendly surfactant such as n-Dodecyl β-D-maltoside. Focus was given on asphaltenes to better understand the mechanisms of surfactant cleanup. Through phase behavior, spontaneous imbibition, dynamic interfacial tension and contact angle measurements, we showed that microemulsions formed by this surfactant are able to mobilize bulk NAPL (containing 9wt.% asphaltenes) in the porous rock and solubilize DNAPL (i.e., 4-6wt.% adsorbed asphaltenes) from the rock surface. Spontaneous imbibition tests, in particular, indicated that the ratio of mobilized to solubilized NAPL is about 6:1. Furthermore, aging the cores in NAPL beyond 3days allowed for more NAPL to be trapped in the large pores of the rock but did not alter the amount of asphaltenes adsorbed on the mineral surface.

  14. Cocrystal solubilization in biorelevant media and its prediction from drug solubilization

    PubMed Central

    Lipert, Maya P.; Roy, Lilly; Childs, Scott L.

    2015-01-01

    This work examines cocrystal solubility in biorelevant media, (FeSSIF, fed state simulated intestinal fluid), and develops a theoretical framework that allows for the simple and quantitative prediction of cocrystal solubilization from drug solubilization. The solubilities of four hydrophobic drugs and seven cocrystals containing these drugs were measured in FeSSIF and in acetate buffer at pH 5.00. In all cases, the cocrystal solubility (Scocrystal) was higher than the drug solubility (Sdrug) in both buffer and FeSSIF; however, the solubilization ratio of drug, SRdrug = (SFeSSIF/Sbuffer)drug, was not the same as the solubilization ratio of cocrystal, SRcocrystal = (SFeSSIF/Sbuffer)cocrystal, meaning drug and cocrystal were not solubilized to the same extent in FeSSIF. This highlights the potential risk of anticipating cocrystal behavior in biorelevant media based on solubility studies in water. Predictions of SRcocrystal from simple equations based only on SRdrug were in excellent agreement with measured values. For 1:1 cocrystals, the cocrystal solubilization ratio can be obtained from the square root of the drug solubilization ratio. For 2:1 cocrystals, SRcocrystal is found from (SRdrug)2/3. The findings in FeSSIF can be generalized to describe cocrystal behavior in other systems involving preferential solubilization of a drug such as surfactants, lipids, and other drug solubilizing media. PMID:26390213

  15. Molecular Model for the Solubilization of Membranes into Nanodisks by Styrene Maleic Acid Copolymers

    PubMed Central

    Scheidelaar, Stefan; Koorengevel, Martijn C.; Pardo, Juan Dominguez; Meeldijk, Johannes D.; Breukink, Eefjan; Killian, J. Antoinette

    2015-01-01

    A recent discovery in membrane research is the ability of styrene-maleic acid (SMA) copolymers to solubilize membranes in the form of nanodisks allowing extraction and purification of membrane proteins from their native environment in a single detergent-free step. This has important implications for membrane research because it allows isolation as well as characterization of proteins and lipids in a near-native environment. Here, we aimed to unravel the molecular mode of action of SMA copolymers by performing systematic studies using model membranes of varying compositions and employing complementary biophysical approaches. We found that the SMA copolymer is a highly efficient membrane-solubilizing agent and that lipid bilayer properties such as fluidity, thickness, lateral pressure profile, and charge density all play distinct roles in the kinetics of solubilization. More specifically, relatively thin membranes, decreased lateral chain pressure, low charge density at the membrane surface, and increased salt concentration promote the speed and yield of vesicle solubilization. Experiments using a native membrane lipid extract showed that the SMA copolymer does not discriminate between different lipids and thus retains the native lipid composition in the solubilized particles. A model is proposed for the mode of action of SMA copolymers in which membrane solubilization is mainly driven by the hydrophobic effect and is further favored by physical properties of the polymer such as its relatively small cross-sectional area and rigid pendant groups. These results may be helpful for development of novel applications for this new type of solubilizing agent, and for optimization of the SMA technology for solubilization of the wide variety of cell membranes found in nature. PMID:25606677

  16. Improvement of Arbuscular Mycorrhiza Development by Inoculation of Soil with Phosphate-Solubilizing Rhizobacteria To Improve Rock Phosphate Bioavailability ((sup32)P) and Nutrient Cycling

    PubMed Central

    Toro, M.; Azcon, R.; Barea, J.

    1997-01-01

    The interactive effect of phosphate-solubilizing bacteria and arbuscular mycorrhizal (AM) fungi on plant use of soil P sources of low bioavailability (endogenous or added as rock phosphate [RP] material) was evaluated by using soil microcosms which integrated (sup32)P isotopic dilution techniques. The microbial inocula consisted of the AM fungus Glomus intraradices and two phosphate-solubilizing rhizobacterial isolates: Enterobacter sp. and Bacillus subtilis. These rhizobacteria behaved as "mycorrhiza helper bacteria" promoting establishment of both the indigenous and the introduced AM endophytes despite a gradual decrease in bacterial population size, which dropped from 10(sup7) at planting to 10(sup3) CFU g(sup-1) of dry rhizosphere soil at harvest. Dual inoculation with G. intraradices and B. subtilis significantly increased biomass and N and P accumulation in plant tissues. Regardless of the rhizobacterium strain and of the addition of RP, AM plants displayed lower specific activity ((sup32)P/(sup31)P) than their comparable controls, suggesting that the plants used P sources not available in their absence. The inoculated rhizobacteria may have released phosphate ions ((sup31)P), either from the added RP or from the less-available indigenous P sources, which were effectively taken up by the external AM mycelium. Soluble Ca deficiency in the test soil may have benefited P solubilization. At least 75% of the P in dually inoculated plants derived from the added RP. It appears that these mycorrhizosphere interactions between bacterial and fungal plant associates contributed to the biogeochemical P cycling, thus promoting a sustainable nutrient supply to plants. PMID:16535730

  17. Phosphorus release capacity of soluble P fertilizers and insoluble rock phosphate in response to phosphate solubilizing bacteria and poultry manure and their effect on plant growth promotion and P utilization efficiency of chilli (Capsicum annuum L.)

    NASA Astrophysics Data System (ADS)

    Abbasi, M. K.; Musa, N.; Manzoor, M.

    2015-01-01

    The ability of soil microorganisms and organic manures to convert insoluble phosphorus (P) to an accessible form offers a biological rescue system for improving P solubilization and utilization in soil-plant systems. Our objective was to examine the P supplying capacity of soluble P fertilizers (SPF) i.e. single super phosphate (SSP) and di-ammonium phosphate (DAP) and insoluble rock phosphate (RP) after adding phosphate solubilizing bacteria (PSB) and poultry manure (PM) and their subsequent effect on the growth, yield and P-utilization efficiency (PUE) of chill (Capsicum annuum L.). An incubation study was carried-out on a sandy loam neutral soil with twelve treatments including T0: control; T1: RP; T2: SSP; T3: DAP; T4: PM; T5: 1/2 RP + 1/2 SSP; T6: 1/2 RP + 1/2 DAP; T7: 1/2 RP + 1/2 PM; T8: RP + PSB; T9: 1/2 RP + 1/2 SSP + PSB; T10: 1/2 RP + 1/2 DAP + PSB; T11: 1/2 RP + 1/2 PM + PSB. Phosphorus release capacity of added amendments was measured by analyzing extractable P from the amended soil incubated under controlled condition at 25 °C for 0, 5, 15, 25, 35, 60 days period. To complement the incubation study, a greenhouse experiment was conducted in pots with chilli (Capsicum annuum L.) used as a test crop. Growth, yield, P-uptake and PUE of the chilli was determined during the study. Results indicated that P release capacity of soil amended with RP varied between 6.0 and 11.5 mg kg-1 while the soluble P fertilizers i.e. SSP and DAP displayed a maximum of 73 and 68 mg P kg-1 at the start of the experiment (day 0). However, the P released tendency from SSP and DAP declined during incubation and at the end 82 and 79% of P initially present had been lost from the mineral pool. Integrated use of PSB and PM with RP in 1/2 RP + 1/2 PM + PSB treatment stimulated P mineralization by releasing a maximum of 25 mg P kg-1 that was maintained at high levels without any loss. Application of PSB tended to decrease pH showing an acidifying effect on soil. In the greenhouse

  18. Effect of silica nanoparticles on microbial biomass and silica availability in maize rhizosphere.

    PubMed

    Rangaraj, Suriyaprabha; Gopalu, Karunakaran; Rathinam, Yuvakkumar; Periasamy, Prabu; Venkatachalam, Rajendran; Narayanasamy, Kannan

    2014-01-01

    The effect of silica nanoparticles and conventional silica sources on the changes in microbial biomass and silica availability to pure soil and maize rhizosphere was studied. Nanosilica (20-40 nm) was synthesized from rice husk and comprehensively characterized. The efficiency of nanosilica was evaluated in terms of its effects on beneficial microbial population such as phosphate solubilizers, nitrogen fixers, silicate solubilizers, microbial biomass carbon and nitrogen content, and silica content in comparison with other silica sources such as microsilica, sodium silicate, and silicic acid. Nanosilica significantly (P < 0.05) enhanced microbial populations, total biomass content (C = 1508 μg g(-1) and N = 178 μg g(-1) ), and silica content (14.75 mg mL(-1) ). Although microsilica sources enhanced factors associated with soil fertility, their use by maize roots and silicification in soil was found to be less. The results show that nanosilica plays a vital role in influencing soil nutrient content and microbial biota and, hence, may promote the growth of maize crop.

  19. The potential for solubilizing agents to enhance the remediation of hydrophobic organic solutes in soil-water suspensions. [Quarterly report

    SciTech Connect

    Laha, S.; Liu, Z.; Edwards, D.; Luthy, R.G.

    1991-02-01

    This paper discusses the feasibility for use of surfactant solubilizing agents to enhance the solubility and the rate of microbial degradation of hydrophobic organic solutes in soil-water suspensions. Hydrophobic organic contaminants are strongly sorbed to soil or sediment material, and as a consequence the rate of microbial degradation may depend greatly on the desorption of the sorbed-phase contaminant and the accessibility of the contaminant to soil microorganisms. Chemical solubilizing agents may enhance the rate of hydrophobic organic solute degradation by increasing the rate of solute desorption from soil and the extent of solute partitioning to the aqueous phase. The presentation will review on-going research on: surfactant solubilization of polycyclic aromatic hydrocarbon (PAH) compounds in clean water, and in soil-water suspensions; and experiments to assess if the addition of surfactant to soil-water suspension results in faster rate of mineralization of PAH compounds in soil.

  20. The potential for solubilizing agents to enhance the remediation of hydrophobic organic solutes in soil-water suspensions

    SciTech Connect

    Laha, S.; Liu, Z.; Edwards, D.; Luthy, R.G.

    1991-02-01

    This paper discusses the feasibility for use of surfactant solubilizing agents to enhance the solubility and the rate of microbial degradation of hydrophobic organic solutes in soil-water suspensions. Hydrophobic organic contaminants are strongly sorbed to soil or sediment material, and as a consequence the rate of microbial degradation may depend greatly on the desorption of the sorbed-phase contaminant and the accessibility of the contaminant to soil microorganisms. Chemical solubilizing agents may enhance the rate of hydrophobic organic solute degradation by increasing the rate of solute desorption from soil and the extent of solute partitioning to the aqueous phase. The presentation will review on-going research on: surfactant solubilization of polycyclic aromatic hydrocarbon (PAH) compounds in clean water, and in soil-water suspensions; and experiments to assess if the addition of surfactant to soil-water suspension results in faster rate of mineralization of PAH compounds in soil.

  1. Rates of solubilization and biodegradation of PAH compounds in porous media

    SciTech Connect

    Luthy, R.G.

    1991-11-01

    Microbial degradation of hydrophobic organic compounds in soils and aquifer media is dependent on rates of desorption of these compounds from solids and rates of solubilization from residual nonaqueous phase liquids (NAPLs). The couples processes involving microbial degradation and hydrophobic compound availability are not well understood. The proposed research effort explores certain physicochemical phenomena that may have a significant affect on the rate of microbial degradation of hydrophobic organic compounds in porous media. The investigation will examine rates of biomineralization of polycyclic aromatic hydrocarbon (PAH) compounds that are leached from a residual saturation of coal tar. Batch and continuously-stirred reactor studies will be used to measure solute equilibrium concentrations and rates of solubilization of PAH compounds from coal tar imbided into microporous silica media. These rates will be compared with rates of mineralization of {sup 14}C-labeled compounds in similar systems inoculated with a culture of PAH degrading microorganisms. Column experiments will also be conducted to assess the rates of solubilization and mass transfer coefficients from coal tar entrapped in a sandy aquifer material by capillary forces.

  2. Rates of solubilization and biodegradation of PAH compounds in porous media. [Quarterly report

    SciTech Connect

    Luthy, R.G.

    1991-11-01

    Microbial degradation of hydrophobic organic compounds in soils and aquifer media is dependent on rates of desorption of these compounds from solids and rates of solubilization from residual nonaqueous phase liquids (NAPLs). The couples processes involving microbial degradation and hydrophobic compound availability are not well understood. The proposed research effort explores certain physicochemical phenomena that may have a significant affect on the rate of microbial degradation of hydrophobic organic compounds in porous media. The investigation will examine rates of biomineralization of polycyclic aromatic hydrocarbon (PAH) compounds that are leached from a residual saturation of coal tar. Batch and continuously-stirred reactor studies will be used to measure solute equilibrium concentrations and rates of solubilization of PAH compounds from coal tar imbided into microporous silica media. These rates will be compared with rates of mineralization of {sup 14}C-labeled compounds in similar systems inoculated with a culture of PAH degrading microorganisms. Column experiments will also be conducted to assess the rates of solubilization and mass transfer coefficients from coal tar entrapped in a sandy aquifer material by capillary forces.

  3. Plant growth promoting potential of the fungus Discosia sp. FIHB 571 from tea rhizosphere tested on chickpea, maize and pea.

    PubMed

    Rahi, P; Vyas, P; Sharma, S; Gulati, Ashu; Gulati, Arvind

    2009-06-01

    The ITS region sequence of a phosphate-solubilizing fungus isolated from the rhizosphere of tea growing in Kangra valley of Himachal Pradesh showed 96% identity with Discosia sp. strain HKUCC 6626 ITS 1, 5.8S rRNA gene and ITS 2 complete sequence, and 28S rRNA gene partial sequence. The fungus exhibited the multiple plant growth promoting attributes of solubilization of inorganic phosphate substrates, production of phytase and siderophores, and biosynthesis of indole acetic acid (IAA)-like auxins. The fungal inoculum significantly increased the root length, shoot length and dry matter in the test plants of maize, pea and chickpea over the uninoculated control under the controlled environment. The plant growth promoting attributes have not been previously studied for the fungus. The fungal strain with its multiple plant growth promoting activities appears attractive towards the development of microbial inoculants.

  4. An ELISA for screening hybridoma cultures for monoclonal antibodies against a detergent solubilized integral membrane protein.

    PubMed

    Noteboom, W D; Knurr, K E; Kim, H S; Richmond, W G; Martin, A P; Vorbeck, M L

    1984-12-14

    A method is described for the binding of a detergent solubilized integral membrane protein to polystyrene immunoassay plates. Addition of Bouin's fluid, a histochemical fixative, to wells of plates containing the detergent solubilized antigen, followed by low speed centrifugation, is sufficient to promote binding of antigen in the presence of Triton X-100 concentrations as high as 1.75%. The binding of antigen is rapid and the entire binding procedure, including removal of fixative and washing of the plates, can be accomplished in less than 15 min. Immunological specificity of the bound antigen is retained. This method has been used to effectively screen hybridoma cultures for specific antibodies.

  5. Field studies on two rock phosphate solubilizing actinomycete isolates as biofertilizer sources

    NASA Astrophysics Data System (ADS)

    Mba, Caroline C.

    1994-03-01

    Recently biotechnology is focusing attention on utilization of biological resources to solve a number of environmental problems such as soil fertility management. Results of microbial studies on earthworm compost in the University of Nigeria farm identified a number of rock phosphate solubilizing actinomycetes. Two of these, isclates 02 and 13, were found to be efficient rock phosphate (RP) solubilizers and fast-growing cellulolytic microbes producing extracellular hydrolase enzymes. In this preliminary field study the two microbial isolates were investigated with respect to their effects on the growth of soybean and egusi as well as their effect on the incidence of toxicity of poultry droppings. Application of these isolates in poultry manure-treated field plots, as microbial fertilizers, brought about yield increases of 43% and 17% with soybeans and 19% and 33% with egusi, respectively. Soil properties were also improved. With isolates 02 and 13, the soil available phosphorus increased at the five-leaf stage, while N-fixation in the soil increased by 45% or 11% relative to control. It was further observed that air-dried poultry manure after four days of incubation was still toxic to soybean. The toxic effect of the applied poultry manure was reduced or eliminated with microbial fertilizers 02 or 13, respectively. The beneficial effects of the microbial organic fertilizer are discussed. Justification for more intensive research on rock phosphate organic fertilizer is highlighted.

  6. Amphiphiles for protein solubilization and stabilization

    DOEpatents

    Gellman, Samuel Helmer; Chae, Pil Seok; Laible, Philip D.; Wander, Marc J.

    2012-09-11

    The invention provides amphiphiles for manipulating membrane proteins. The amphiphiles can feature carbohydrate-derived hydrophilic groups and branchpoints in the hydrophilic moiety and/or in a lipophilic moiety. Such amphiphiles are useful as detergents for solubilization and stabilization of membrane proteins, including photosynthetic protein superassemblies obtained from bacterial membranes.

  7. Amphiphiles for protein solubilization and stabilization

    DOEpatents

    Gellman, Samuel Helmer; Chae, Pil Seok; Laible, Phillip D; Wander, Marc J

    2014-11-04

    The invention provides amphiphiles for manipulating membrane proteins. The amphiphiles can feature carbohydrate-derived hydrophilic groups and branchpoints in the hydrophilic moiety and/or in a lipophilic moiety. Such amphiphiles are useful as detergents for solubilization and stabilization of membrane proteins, including photosynthetic protein superassemblies obtained from bacterial membranes.

  8. Kinetics of degradation of surfactant-solubilized fluoranthene by a Sphingomonas paucimobilis

    SciTech Connect

    Willumsen, P.A. . Dept. of Marine Ecology and Microbiology); Arvin, E. . Dept. of Environmental Science and Engineering)

    1999-08-01

    To achieve a better quantitative understanding of the stimulating or inhibiting effect of surfactants on the metabolism of polycyclic aromatic hydrocarbons (PAHs), a biodegradation model describing solubilization, bioavailability, and biodegradation of crystalline fluoranthene is proposed and used to model experimental data. The degradation was investigated in batch systems containing the PAH-degrading bacterium Sphingomonas paucimobilis strain EPA505, the nonionic surfactant Triton X-100, and a fluoranthene-amended liquid mineral salts medium. Surfactant-enhanced biodegradation is complex; however, the biodegradation model predicted fluoranthene disappearance and the initial mineralization well. Surfactant-amendment did increase fluoranthene mineralization rates by strain EPA505; however, the increases were not proportional to the rates of fluoranthene solubilization. The surfactant clearly influenced the microbial PAH metabolism as indicated by a rapid accumulation of colored products and by a surfactant -related decreased in the overall extent of fluoranthene mineralization. Model estimations of the bioavailability of micelle-solubilized fluoranthene, the relatively fast fluoranthene disappearance, and the accumulation of extracellular compounds in the degradation system suggest that low availability of micellar fluoranthene is not the only factor controlling surfactant-enhanced biodegradation. Also factors such as the extent of accumulation and bioavailability of the PAH metabolites and the crystalline solubilization rate in the presence of surfactants may determine the overall effect of surfactant-enhanced biodegradation of high molecular weight PAHs.

  9. Lung protection by inhalation of exogenous solubilized extracellular matrix

    PubMed Central

    Wu, Jinglei; Ravikumar, Priya; Nguyen, Kytai T.; Hsia, Connie C. W.

    2017-01-01

    Decellularized extracellular matrix (ECM) contains complex tissue-specific components that work in concert to promote tissue repair and constructive remodeling and has been used experimentally and clinically to accelerate epithelial wound repair, leading us to hypothesize that lung-derived ECM could mitigate acute lung injury. To explore the therapeutic potential of ECM for noninvasive delivery to the lung, we decellularized and solubilized porcine lung ECM, then characterized the composition, concentration, particle size and stability of the preparation. The ECM preparation at 3.2 mg/mL with average particle size <3 μm was tested in vitro on human A549 lung epithelial cells exposed to 95% O2 for 24 hours, and in vivo by tracheal instillation or nebulization into the lungs of rats exposed intermittently or continuously to 90% O2 for a cumulative 72 hours. Our results showed that the preparation was enriched in collagen, reduced in glycosaminoglycans, and contained various bioactive molecules. Particle size was concentration-dependent. Compared to the respective controls treated with cell culture medium in vitro or saline in vivo, ECM inhalation normalized cell survival and alveolar morphology, and reduced hyperoxia-induced apoptosis and oxidative damage. This proof-of-concept study established the methodology, feasibility and therapeutic potential of exogenous solubilized ECM for pulmonary cytoprotection, possibly as an adjunct or potentiator of conventional therapy. PMID:28151947

  10. Microbial activity promoted with organic carbon accumulation in macroaggregates of paddy soils under long-term rice cultivation

    NASA Astrophysics Data System (ADS)

    Liu, Yalong; Wang, Ping; Ding, Yuanjun; Lu, Haifei; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Filley, Timothy; Zhang, Xuhui; Zheng, Jinwei; Pan, Genxing

    2016-12-01

    sharply but the diversity gently, with decreasing size of the aggregate fractions. The soil respiration quotient (ratio of respired CO2-C to SOC) was the highest in the silt fraction, followed by the fine-sand fraction, but the lowest in coarse-sand and clay fractions in the rice soils cultivated over 100 years, whereas the microbial metabolic quotient was lower in coarse-sand-sized fractions than in other fractions. Soil respiration was higher in the silt fraction than in other fractions for the rice soils. For the size fractions other than the clay fraction, enzyme activity was increased with prolonged rice cultivation, whereas soil respiration appeared to have a decreasing trend. Only in the coarse-sand fraction was both microbial gene abundance and enzyme activity well correlated to SOC and LOC content, although the chemical stability and respiratory of SOC were similar between coarse-sand and clay fractions. Thus, biological activity was generally promoted with LOC accumulation in the coarse-sand-sized macroaggregates of the rice soils, positively responding to prolonged rice cultivation management. The finding here provides a mechanistic understanding of soil organic carbon turnover and microbial community succession at fine scale of soil aggregates that have evolved along with anthropogenic activity of rice cultivation in the field.

  11. Bacteria as growth-promoting agents for citrus rootstocks.

    PubMed

    Giassi, Valdionei; Kiritani, Camila; Kupper, Katia Cristina

    2016-09-01

    The microbial community plays an essential role in maintaining the ecological balance of soils. Interactions between microorganisms and plants have a major influence on the nutrition and health of the latter, and growth-promoting rhizobacteria can be used to improve plant development through a wide range of mechanisms. Therefore, the objective of the present study was to evaluate bacteria as growth-promoting agents for citrus rootstocks. A total of 30 bacterial isolates (11 of Bacillus spp., 11 actinobacteria, and 8 lactic acid bacteria) were evaluated in vitro for indoleacetic acid production, phosphate solubilization, and nitrogen (N) fixation. In vivo testing consisted of growth promotion trials of the bacterial isolates that yielded the best results on in vitro tests with three rootstocks: Swingle citrumelo [Citrus×paradisi Macfad cv. Duncan×Poncirus trifoliata (L.) Raf.], Sunki mandarin (Citrus sunki Hort. ex Tan), and rangpur (Citrus×limonia Osbeck). The parameters of interest were height, number of leaves, stem diameter, shoot and root dry mass, and total dry mass at 150days after germination. The results showed that most bacterial isolates were capable of IAA production. Only one lactic acid bacterium isolate (BL06) solubilized phosphate, with a high solubilization index (PSI>3). In the actinobacteria group, isolates ACT01 (PSI=2.09) and ACT07 (PSI=2.01) exhibited moderate phosphate-solubilizing properties. Of the Bacillus spp. isolates, only CPMO6 and BM17 solubilized phosphate. The bacterial isolates that most fixated nitrogen were BM17, ACT11, and BL24. In the present study, some bacteria were able to promote growth of citrus rootstocks; however, this response was dependent on plant genotype and isolate. Bacillus spp. BM16 and CPMO4 were able to promote growth of Swingle citrumelo. In Sunki mandarin plants, the best treatment results were obtained with BM17 (Bacillus sp.) and ACT11 (actinobacteria). For Rangpur lime rootstock, only BM05 (Bacillus sp

  12. H. hepaticus-induced liver tumor promotion is associated with increased serum bile acid and a persistent microbial-induced immune response

    PubMed Central

    García, Alexis; Zeng, Yu; Muthupalani, Sureshkumar; Ge, Zhongming; Potter, Amanda; Mobley, Melissa W.; Boussahmain, Chakib; Feng, Yan; Wishnok, John S.; Fox, James G.

    2011-01-01

    Chronic microbial infection influence cancer progression but the mechanisms that link them remain unclear. Constitutive androstane receptor (CAR) is a nuclear receptor that regulates enzymes involved in endobiotic and xenobiotic metabolism. CAR activation is a mechanism of xenobiotic tumor promotion, however, the effects of chronic microbial infection on tumor promotion have not been studied in the context of CAR function. Here we report that CAR limits the effects of chronic infection-associated progression of liver cancer. CAR knockout (KO) and wild-type (WT) male mice were treated or not with the tumor initiator diethylnitrosamine (DEN) at 5 weeks of age and then orally inoculated with Helicobacter hepaticus (Hh) or sterile media at 8 weeks of age. At 50 weeks postinoculation mice were euthanized for histopathological, microbiological, molecular, and metabolomic analyses. Hh infection induced comparable hepatitis in WT and KO mice with or without DEN that correlated with significant upregulation of Tnfα and toll receptor Tlr2. Notably, DEN-treated Hh-infected KO mice exhibited increased numbers of liver lobes with dysplasia and neoplasia, as well as increased multiplicity of neoplasia, relative to similarly treated WT mice. Enhanced tumor promotion was associated with decreased hepatic expression of P450 enzymes Cyp2b10 and Cyp3a11, increased expression of Camp, and increased serum concentrations of chenodeoxycholic acid. Together, our findings suggest that liver tumor promotion is enhanced by an impaired metabolic detoxification of endobiotics and a persistent microbial-induced immune response. PMID:21335546

  13. Prediction of inclusion body solubilization from shaken to stirred reactors.

    PubMed

    Walther, Cornelia; Mayer, Sabrina; Trefilov, Alexandru; Sekot, Gerhard; Hahn, Rainer; Jungbauer, Alois; Dürauer, Astrid

    2014-01-01

    Inclusion bodies (IBs) were solubilized in a µ-scale system using shaking microtiter plates or a stirred tank reactor in a laboratory setting. Characteristic dimensionless numbers for mixing, the Phase number Ph and Reynolds number Re did not correlate with the kinetics and equilibrium of protein solubilization. The solubilization kinetics was independent of the mixing system, stirring or shaking rate, shaking diameter, and energy input. Good agreement was observed between the solubilization kinetics and yield on the µ-scale and laboratory setting. We show that the IB solubilization process is controlled predominantly by pore diffusion. Thus, for the process it is sufficient to keep the IBs homogeneously suspended, and additional power input will not improve the process. The high-throughput system developed on the µ-scale can predict solubilization in stirred reactors up to a factor of 500 and can therefore be used to determine optimal solubilization conditions on laboratory and industrial scale.

  14. Solubilization of Australian lignites by microorganisms

    SciTech Connect

    Catcheside, D.E.A.; Mallett, K.J.; Cox, R.E.

    1988-01-01

    Australia has substantial lignite deposits, particularly in the Latrobe Valley in Victoria where 4.10/sup 10/ tons are accessible with available technologies. The authors have investigated the susceptibility of these coal to solubilization by microorganisms, including species additional to those already identified as active on North American lignites. The data presented here show that acid oxidized lignites from the Latrobe Valley are solubilized by each of seven species of microorganisms previously found to be active on Leonardite and oxidized North American lignites. These are the wood rot fungi: Trametes versicolor, Poria placenta and Phanerochaete chrysosporium, the lignin degrading prokaryote Streptomyces viridosporus and three fungi isolated from lignite in Mississippi: Candida ML-13, Cunninghamelia YML-1 and Penicillium waksmanii.

  15. Differential Precipitation and Solubilization of Proteins.

    PubMed

    Ryan, Barry J; Kinsella, Gemma K

    2017-01-01

    Differential protein precipitation is a rapid and economical step in protein purification and is based on exploiting the inherent physicochemical properties of the polypeptide. Precipitation of recombinant proteins, lysed from the host cell, is commonly used to concentrate the protein of choice before further polishing steps with more selective purification columns (e.g., His-Tag, Size Exclusion, etc.). Recombinant proteins can also precipitate naturally as inclusion bodies due to various influences during overexpression in the host cell. Although this phenomenon permits easier initial separation from native proteins, these inclusion bodies must carefully be differentially solubilized so as to reform functional, correctly folded proteins. Here, appropriate bioinformatics tools to aid in understanding a protein's propensity to aggregate and solubilize are explored as a backdrop for a typical protein extraction, precipitation, and selective resolubilization procedure, based on a recombinantly expressed protein.

  16. Large scale solubilization of coal and bioconversion to utilizable energy. Third quarterly technical progress report, April 1, 1994--June 30, 1994

    SciTech Connect

    Mishra, N.C.

    1994-08-01

    In order to develop a system for a large scale coal solubilization and its bioconversion to utilizable fuel, the investigators plan to clone the genes encoding Neurospora protein that facilitate depolymerization of coal. They also plan to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms. In addition the product of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein. Main objectives are: (1) cloning of Neurospora gene for coal depolymerization protein controlling solubilization in different host cells, utilizing Neurospora plasmid and other vector(s); (2) (a) development of a large scale electrophoretic separation of coal drived products obtained after microbial solubilization; (b) identification of the coal derived products obtained after biosolubilization by Neurospora cultures or obtained after Neurospora enzyme catalyzed reaction in in vitro by the wildtype and mutant enzymes; (3) bioconversion of coal drived products into utilizable fuel; and (4) characterization of Neurospora wildtype and mutant CSA protein(s) involved in solubilization of coal in order to assess the nature of the mechanism of solubilization and the role of Neurospora proteins in this process.

  17. Stress-tolerant P-solubilizing microorganisms.

    PubMed

    Vassilev, N; Eichler-Löbermann, B; Vassileva, M

    2012-08-01

    Drought, high/low temperature, and salinity are abiotic stress factors accepted as the main reason for crop yield losses in a world with growing population and food price increases. Additional problems create nutrient limitations and particularly low P soil status. The problem of phosphate fertilizers, P plant nutrition, and existing phosphate bearing resources can also be related to the scarcity of rock phosphate. The modern agricultural systems are highly dependent on the existing fertilizer industry based exclusively of this natural, finite, non-renewable resource. Biotechnology offers a number of sustainable solutions that can mitigate these problems by using plant beneficial, including P-solubilizing, microorganisms. This short review paper summarizes the current and future trends in isolation, development, and application of P-solubilizing microorganisms in stress environmental conditions bearing also in mind the imbalanced cycling and unsustainable management of P. Special attention is devoted to the efforts on development of biotechnological strategies for formulation of P-solubilizing microorganisms in order to increase their protection against adverse abiotic factors.

  18. Promotion

    PubMed Central

    Alam, Hasan B.

    2013-01-01

    This article gives an overview of the promotion process in an academic medical center. A description of different promotional tracks, tenure and endowed chairs, and the process of submitting an application is provided. Finally, some practical advice about developing skills and attributes that can help with academic growth and promotion is dispensed. PMID:24436683

  19. Formation of single domain magnetite by green rust oxidation promoted by microbial anaerobic nitrate-dependent iron oxidation

    NASA Astrophysics Data System (ADS)

    Miot, Jennyfer; Li, Jinhua; Benzerara, Karim; Sougrati, Moulay Tahar; Ona-Nguema, Georges; Bernard, Sylvain; Jumas, Jean-Claude; Guyot, François

    2014-08-01

    Biomineralization of magnetite is a central geomicrobiological process that might have played a primordial role over Earth’s history, possibly leaving traces of life in the geological record or controlling trace metal(loid)s and organic pollutants mobility in modern environments. Magnetite biomineralization has been attributed to two main microbial pathways to date (namely magnetotactic bacteria and dissimilatory iron-reducing bacteria). Here, we uncover a new route of magnetite biomineralization involving the anaerobic nitrate-reducing iron(II) oxidizing bacterium Acidovorax sp. strain BoFeN1. Using transmission electron microscopy, scanning transmission X-ray microscopy, transmission Mössbauer spectroscopy and rock magnetic analyses, this strain is shown to promote the transformation of hydroxychloride green rust in equilibrium with dissolved Fe(II) to (1) periplasmic lepidocrocite (γ-FeOOH) and (2) extracellular magnetite, thus leading to strong redox heterogeneities at the nanometer scale. On the one hand, lepidocrocite was associated with protein moieties and exhibited an anisotropic texture, with the elongated axis parallel to the cell wall. On the other hand, magnetite crystals exhibited grain sizes and magnetic properties consistent with stable single domain particles. By comparison, abiotic controls led to a very slow (4 months vs. 2 days in BoFeN1 cultures) and incomplete oxidation of hydroxychloride green rust towards magnetite. As this abiotic magnetite exhibited the same size and magnetic properties (stable single domain particles) as magnetite produced in BoFeN1 cultures, only the co-occurrence of textured Fe(III)-oxides and magnetite, associated with the persistence of organic carbon molecules, might constitute valuable biosignatures to be looked for in the geological record. Our results furthermore contribute to a more complex picture of Fe redox cycling in the environment, providing an additional process of Fe(II)-bearing phase

  20. Metal solubilization from metal-containing solid materials by cyanogenic Chromobacterium violaceum.

    PubMed

    Faramarzi, Mohammad A; Stagars, Marion; Pensini, Enrico; Krebs, Walter; Brandl, Helmut

    2004-09-30

    Different cyanogenic bacterial strains (Chromobacterium violaceum, Pseudomonas fluorescens, Bacillus megaterium) were cultivated under cyanide-forming conditions in the presence of metal-containing solids such as nickel powder or electronic scrap. All microorganisms were able to form water-soluble metal cyanides, however, with different efficiencies. C. violaceum was able to mobilize nickel as tetracyanonickelate [Ni(CN)4(2-)] from fine-grained nickel powder. Gold was microbially solubilized as dicyanaoaurate [Au(CN)2-] from electronic waste. Additionally, cyanide-complexed copper was detected during biological treatment of shredded printed circuit boards scrap. Regarding the formation of tetracyanonickelate, C. violaceum was more effective than P. fluorescens or B. megaterium. Besides a few previous reports on gold solubilization from gold-containing ores or native gold by C. violaceum, the findings demonstrate for the first time the microbial mobilization of metals other than gold from solid materials and represent a novel type of microbial metal mobilization based on the ability of certain microbes to form HCN. The results might have the potential for industrial applications (biorecovery, bioremediation) regarding the treatment of metal-containing solids since metal cyanides can easily be separated by chromatographic means and be recovered by sorption onto activated carbon.

  1. Solubilization and biodegradation of polycyclic aromatic hydrocarbon compounds in soil-water suspensions with surfactants

    SciTech Connect

    Laha, S.

    1992-01-01

    Hydrophobic organic compounds (HOCs) sorb strongly onto soil and sediment material, and the effectiveness of microbial treatment can be diminished by HOC phase partitioning and decreased substrate accessibility to microorganisms. Surfactant addition has been suggested as a technique for decreasing the interfacial tension and partitioning of the HOC with soil, and thereby increasing HOC mobility and bioavailability. However, this study indicates that nonionic surfactant solubilization of HOCs from soil may not be beneficial for the enhancement of soil bioremediation. The solubilization and microbial degradation of phenanthrene, a three-ring polycyclic aromatic hydrocarbon (PAH) compound, was examined in various soil-water systems with commercially-available surface-active agents. This was accomplished by a series of batch tests using radiolabeled techniques. The purpose of surfactant addition was to assess the effect of surfactant solubilization of PAHs on their biodegradation. For soil-water suspensions without surfactant approximately 50-60% of the phenanthrene was mineralized over the course of ten weeks. The addition of nonionic surface-active agents was observed not to be beneficial for microbial mineralization of phenanthrene in the soil-water systems, and for supra-CMC surfactant doses phenanthrene mineralization was completely inhibited for all the surfactants tested. Sub-CMC levels of surfactant in the soil-water systems generally did not have an inhibitory effect on phenanthrene mineralization, but neither did such doses serve to enhance the rate of degradation, which proceeded most rapidly in the absence of any surfactant. Companion tests suggest that the supra-CMC inhibitory effect is not a toxicity phenomenon, per se, of the surfactant or micellized PAH. An assessment of the results from the various experiments suggest that the inhibitory effect is probably related to a reversible physiological surfactant micelle-bacteria interaction.

  2. Solubilization of herbicides by single and mixed commercial surfactants.

    PubMed

    Galán-Jiménez, M C; Gómez-Pantoja, E; Morillo, E; Undabeytia, T

    2015-12-15

    The solubilization capabilities of micellar solutions of three single surfactants, two alcohol alkoxylates B048 and B266, and the tallow alkyl ethoxylated amine ET15, and their equimolar mixed solutions toward the herbicides flurtamone (FL), metribuzin (MTZ) and mesotrione (MST) were investigated. The solubilization capacity was quantified in terms of the molar solubilization ratio (MSR), critical micellar concentration (CMC), micelle-water partition coefficient (Kmc), binding constant (K1), number of aggregation (Nagg) and Stern-Volmer constant (Ksv). The herbicides were greatly solubilized into different loci of the micelles: FL within the inner hydrophobic core, MST at the micelle/water interface and MTZ in the palisade region. Equimolar binary surfactant mixtures did not improve the solubilization of herbicides over those of single components, with the exception of MTZ by the B266/ET15 system which enhanced solubilization by 10-20%. This enhanced solubilization of MTZ was due to an increased number of micelles that arise from both the intermediate Nagg relative to that of the single surfactants and the lower CMC. The use of Ksv values was a better predictor of the solubilization of polar molecules within binary mixtures of these surfactants than the interaction parameter β(M) from regular solution theory (RST). The results herein suggest that the use of mixed surfactant systems for the solubilization of polar molecules in environmental remediation technologies may be very limited in scope, without clear advantages over the use of single surfactant systems.

  3. Solubilizing excipients in oral and injectable formulations.

    PubMed

    Strickley, Robert G

    2004-02-01

    A review of commercially available oral and injectable solution formulations reveals that the solubilizing excipients include water-soluble organic solvents (polyethylene glycol 300, polyethylene glycol 400, ethanol, propylene glycol, glycerin, N-methyl-2-pyrrolidone, dimethylacetamide, and dimethylsulfoxide), non-ionic surfactants (Cremophor EL, Cremophor RH 40, Cremophor RH 60, d-alpha-tocopherol polyethylene glycol 1000 succinate, polysorbate 20, polysorbate 80, Solutol HS 15, sorbitan monooleate, poloxamer 407, Labrafil M-1944CS, Labrafil M-2125CS, Labrasol, Gellucire 44/14, Softigen 767, and mono- and di-fatty acid esters of PEG 300, 400, or 1750), water-insoluble lipids (castor oil, corn oil, cottonseed oil, olive oil, peanut oil, peppermint oil, safflower oil, sesame oil, soybean oil, hydrogenated vegetable oils, hydrogenated soybean oil, and medium-chain triglycerides of coconut oil and palm seed oil), organic liquids/semi-solids (beeswax, d-alpha-tocopherol, oleic acid, medium-chain mono- and diglycerides), various cyclodextrins (alpha-cyclodextrin, beta-cyclodextrin, hydroxypropyl-beta-cyclodextrin, and sulfobutylether-beta-cyclodextrin), and phospholipids (hydrogenated soy phosphatidylcholine, distearoylphosphatidylglycerol, L-alpha-dimyristoylphosphatidylcholine, L-alpha-dimyristoylphosphatidylglycerol). The chemical techniques to solubilize water-insoluble drugs for oral and injection administration include pH adjustment, cosolvents, complexation, microemulsions, self-emulsifying drug delivery systems, micelles, liposomes, and emulsions.

  4. Microbial reduction of structural Fe3+ in nontronite by a thermophilic bacterium and its role in promoting the smectite to illite reaction

    USGS Publications Warehouse

    Zhang, G.; Dong, H.; Kim, J.; Eberl, D.D.

    2007-01-01

    The illitization process of Fe-rich smectite (nontronite NAu-2) promoted by microbial reduction of structural Fe3+ was investigated by using a thermophilic metal-reducing bacterium, Thermoanaerobacter ethanolicus, isolated from the deep subsurface. T. ethanolicus was incubated with lactate as the sole electron donor and structural Fe3+ in nontronite as the sole electron acceptor, and anthraquinone-2, 6-disulfonate (AQDS) as an electron shuttle in a growth medium (pH 6.2 and 9.2, 65 ??C) with or without an external supply of Al and K sources. With an external supply of Al and K, the extent of reduction of Fe3+ in NAu-2 was 43.7 and 40.4% at pH 6.2 and 9.2, respectively. X-ray diffraction and scanning and transmission electron microscopy revealed formation of discrete illite at pH 9.2 with external Al and K sources, while mixed layers of illite/smectite or highly charged smectite were detected under other conditions. The morphology of biogenic illite evolved from lath and flake to pseudo-hexagonal shape. An external supply of Al and K under alkaline conditions enhances the smectite-illite reaction during microbial Fe3+ reduction of smectite. Biogenic SiO2 was observed as a result of bioreduction under all conditions. The microbially promoted smectite-illite reaction proceeds via dissolution of smectite and precipitation of illite. Thermophilic iron reducing bacteria have a significant role in promoting the smectite to illite reaction under conditions common in sedimentary basins.

  5. Plant growth-promoting and rhizosphere-competent Acinetobacter rhizosphaerae strain BIHB 723 from the cold deserts of the Himalayas.

    PubMed

    Gulati, Arvind; Vyas, Pratibha; Rahi, Praveen; Kasana, Ramesh Chand

    2009-04-01

    A phosphate-solubilizing bacterial strain BIHB 723 isolated from the rhizosphere of Hippophae rhamnoides was identified as Acinetobacter rhizosphaerae on the basis of phenotypic characteristics, carbon source utilization pattern, fatty acid methyl esters analysis, and 16S rRNA gene sequence. The strain exhibited the plant growth-promoting attributes of inorganic and organic phosphate solubilization, auxin production, 1-aminocyclopropane-1-carboxylate deaminase activity, ammonia generation, and siderophore production. A significant increase in the growth of pea, chickpea, maize, and barley was recorded for inoculations under controlled conditions. Field testing with the pea also showed a significant increment in plant growth and yield. The rifampicin mutant of the bacterial strain effectively colonized the pea rhizosphere without adversely affecting the resident microbial populations.

  6. Statistical Optimization of Medium Components for Mass Production of Plant Growth-Promoting Microbial Inoculant Pseudomonas trivialis BIHB 745 (MTCC5336).

    PubMed

    Vyas, Pratibha; Rahi, Praveen; Chadha, B S; Gulati, Arvind

    2014-06-01

    Optimizing nutritional requirements for mass production of microbial inoculants in shortened time has relevance for their economical field application. Therefore, the present study aimed at selecting suitable growth medium, optimizing its components, and up-scaling inoculum production for plant growth-promoting Pseudomonas trivialis BIHB 745. Of the different media tested, the culture exhibited maximal viable colony count in trypticase soya broth with 17.6 % increased biomass on optimizing levels of carbon source, nitrogen source, and NaCl using response surface methodology. A twofold higher biomass with 9 h shorter incubation period was obtained in optimized medium in a bioreactor in comparison to shake flasks.

  7. Haloarchaea Endowed with Phosphorus Solubilization Attribute Implicated in Phosphorus Cycle

    PubMed Central

    Yadav, Ajar Nath; Sharma, Divya; Gulati, Sneha; Singh, Surender; Dey, Rinku; Pal, Kamal Krishna; Kaushik, Rajeev; Saxena, Anil Kumar

    2015-01-01

    Archaea are unique microorganisms that are present in ecological niches of high temperature, pH and salinity. A total of 157 archaea were obtained from thirteen sediment, water and rhizospheric soil samples collected from Rann of Kutch, Gujarat, India. With an aim to screen phosphate solubilizing archaea, a new medium was designed as Haloarchaea P Solubilization (HPS) medium. The medium supported the growth and P solubilization activity of archaea. Employing the HPS medium, twenty isolates showed the P-solubilization. Phosphate solubilizing archaea were identified as seventeen distinct species of eleven genera namely Haloarcula, Halobacterium, Halococcus, Haloferax, Halolamina, Halosarcina, Halostagnicola, Haloterrigena, Natrialba, Natrinema and Natronoarchaeum. Natrinema sp. strain IARI-WRAB2 was identified as the most efficient P-solubilizer (134.61 mg/L) followed by Halococcus hamelinensis strain IARI-SNS2 (112.56 mg/L). HPLC analysis detected seven different kinds of organic acids, namely: gluconic acid, citric acid, formic acid, fumaric acid succinic acid, propionic acid and tartaric acid from the cultures of these isolates. These phosphate solubilizing halophilic archaea may play a role in P nutrition to vegetation growing in these hypersaline soils. This is the first report for these haloarchaea to solubilize considerable amount of P by production of organic acids and lowering of pH. PMID:26216440

  8. Association of endogenous substrate with solubilized bovine brain sialidase.

    PubMed

    Schengrund, C L; Repman, M A

    1986-01-01

    Nonidet P40 solubilized up to 90% of the sialidase, active towards added ganglioside substrate, that was associated with the total membrane fraction prepared from gray matter of bovine brains. Solubilized sialidase acted upon endogenous substrate (sialic acid containing compounds solubilized with the enzyme), hydrolyzing approximately 50% of the readily available sialosyl residues within 20 min. During a 2-hr reaction time 80% of the polysialylated gangliosides solubilized with the enzyme were acted upon. A 20-min lag was observed before sialidase acted upon added ganglioside substrate. The lag could be reduced to less than 2 min when the enzyme was allowed to act on endogenous substrate prior to exposure to exogenous substrate, suggesting that the solubilized enzyme acted preferentially on endogenous substrate. A protease inhibitor prevented much of the 86% loss of activity towards added substrate that was seen when the enzyme was stored at 4 degrees C for 6 days; activity towards endogenous substrate decreased only 34%.

  9. Biochemical and molecular characterization of potential phosphate-solubilizing bacteria in acid sulfate soils and their beneficial effects on rice growth.

    PubMed

    Panhwar, Qurban Ali; Naher, Umme Aminun; Shamshuddin, Jusop; Jusop, Shamshuddin; Othman, Radziah; Latif, Md Abdul; Ismail, Mohd Razi

    2014-01-01

    A study was conducted to determine the total microbial population, the occurrence of growth promoting bacteria and their beneficial traits in acid sulfate soils. The mechanisms by which the bacteria enhance rice seedlings grown under high Al and low pH stress were investigated. Soils and rice root samples were randomly collected from four sites in the study area (Kelantan, Malaysia). The topsoil pH and exchangeable Al ranged from 3.3 to 4.7 and 1.24 to 4.25 cmol(c) kg(-1), respectively, which are considered unsuitable for rice production. Total bacterial and actinomycetes population in the acidic soils were found to be higher than fungal populations. A total of 21 phosphate-solubilizing bacteria (PSB) including 19 N2-fixing strains were isolated from the acid sulfate soil. Using 16S rRNA gene sequence analysis, three potential PSB strains based on their beneficial characteristics were identified (Burkholderia thailandensis, Sphingomonas pituitosa and Burkholderia seminalis). The isolated strains were capable of producing indoleacetic acid (IAA) and organic acids that were able to reduce Al availability via a chelation process. These PSB isolates solubilized P (43.65%) existing in the growth media within 72 hours of incubation. Seedling of rice variety, MR 219, grown at pH 4, and with different concentrations of Al (0, 50 and 100 µM) was inoculated with these PSB strains. Results showed that the bacteria increased the pH with a concomitant reduction in Al concentration, which translated into better rice growth. The improved root volume and seedling dry weight of the inoculated plants indicated the potential of these isolates to be used in a bio-fertilizer formulation for rice cultivation on acid sulfate soils.

  10. Soil Microbial Activity Benchmarks (Provisional) for Ecological Risk Assessments at Explosives-Contaminated Sites: Promoting Range Sustainability

    DTIC Science & Technology

    2008-12-01

    identifiable phospholipid fatty acids (PLFAs) from 34 to 14 (Fuller and Manning, 2004). Actinomycetes were reported to have a substantially lower EC50... actinomycetes is unclear at the present time. Sensitive techniques routinely detected differences in generic microbial community functions at low TNT

  11. Solubilization of nutraceuticals into reverse hexagonal mesophases.

    PubMed

    Amar-Yuli, Idit; Aserin, Abraham; Garti, Nissim

    2008-08-21

    The solubilization of four bioactive molecules with different polarities, in three reverse hexagonal (HII) systems has been investigated. The three HII systems were a typical reverse hexagonal composed of glycerol monooleate (GMO)/tricaprylin/water and two fluid hexagonal systems containing either 2.75 wt % Transcutol or ethanol as a fourth component. The phase behavior of the liquid crystalline phases in the presence of ascorbic acid, ascorbyl palmitate, D-alpha-tocopherol and D-alpha-tocopherol acetate were determined by small-angle X-ray scattering (SAXS) and optical microscopy. Differential scanning calorimetry (DSC) and Fourier-transform infrared (FT-IR) techniques were utilized to follow modifications in the thermal behavior and in the vibrations of different functional groups upon solubilizing the bioactive molecules. The nature of each guest molecule (in both geometry and polarity) together with the different HII structures (typical and fluids) determined the corresponding phase behavior, swelling or structural transformations and its location in the HII structures. Ascorbic acid was found to act as a chaotropic guest molecule, localized in the water-rich core and at the interface. The AP was also a chaotropic guest molecule with its head located in the vicinity of the GMO headgroup while its tail embedded close to the surfactant tail. D-alpha-tocopherol and D-alpha-tocopherol acetate were incorporated between the GMO tails; however, the D-alpha-tocopherol was located closer to the interface. Once Transcutol or ethanol was present and upon guest molecule incorporation, partial migration was detected.

  12. Isolation and characterization of a heavy metal-resistant Burkholderia sp. from heavy metal-contaminated paddy field soil and its potential in promoting plant growth and heavy metal accumulation in metal-polluted soil.

    PubMed

    Jiang, Chun-yu; Sheng, Xia-fang; Qian, Meng; Wang, Qing-ya

    2008-05-01

    A heavy metal-resistant bacterial strain was isolated from heavy metal-contaminated soils and identified as Burkholderia sp. J62 based on the 16S rDNA gene sequence analysis. The heavy metal- and antibiotic resistance, heavy metal solubilization of the isolate were investigated. The isolate was also evaluated for promoting plant growth and Pb and Cd uptakes of the plants from heavy metal-contaminated soils in pot experiments. The isolate was found to exhibit different multiple heavy metal and antibiotic resistance characteristics. Atomic absorption spectrometer analysis showed increased bacterial solubilization of lead and cadmium in solution culture and in soils. The isolate produced indole acetic acid, siderophore and 1-aminocyclopropane-1-carboxylate deaminase. The isolate also solubilized inorganic phosphate. Inoculation with the isolate was found to significantly (p<0.05) increase the biomass of maize and tomato plants. Increase in tissue Pb and Cd contents varied from 38% to 192% and from 5% to 191% in inoculated plants growing in heavy metal-contaminated soils compared to the uninoculated control, respectively. These results show that heavy metal-solubilizing and plant growth promoting bacteria are important for plant growth and heavy metal uptake which may provide a new microbial enhanced-phytoremediation of metal-polluted soils.

  13. Solubilization and purification of melatonin receptors from lizard brain

    SciTech Connect

    Rivkees, S.A.; Conron, R.W. Jr.; Reppert, S.M. )

    1990-09-01

    Melatonin receptors in lizard brain were identified and characterized using {sup 125}I-labeled melatonin (({sup 125}I)MEL) after solubilization with the detergent digitonin. Saturation studies of solubilized material revealed a high affinity binding site, with an apparent equilibrium dissociation constant of 181 +/- 45 pM. Binding was reversible and inhibited by melatonin and closely related analogs, but not by serotonin or norepinephrine. Treatment of solubilized material with the non-hydrolyzable GTP analog, guanosine 5'-(3-O-thiotriphosphate) (GTP-gamma-S), significantly reduced receptor affinity. Gel filtration chromatography of solubilized melatonin receptors revealed a high affinity, large (Mr 400,000) peak of specific binding. Pretreatment with GTP-gamma-S before solubilization resulted in elution of a lower affinity, smaller (Mr 150,000) peak of specific binding. To purify solubilized receptors, a novel affinity chromatography resin was developed by coupling 6-hydroxymelatonin with Epoxy-activated Sepharose 6B. Using this resin, melatonin receptors were purified approximately 10,000-fold. Purified material retained the pharmacologic specificity of melatonin receptors. These results show that melatonin receptors that bind ligand after detergent treatment can be solubilized and substantially purified by affinity chromatography.

  14. Phosphate Solubilization Potentials of Rhizosphere Isolates from Central Anatolia (Turkey)

    NASA Astrophysics Data System (ADS)

    Ogut, M.; Er, F.

    2009-04-01

    Plant available-phosphorus (P) is usually low in Anatolian soils due mainly to the precipitation as calcium (Ca) and magnesium (Mg) phosphates in alkaline conditions. Phosphate solubilizing microorganisms (PSM) can enhance plant P-availability by dissolving the hardly soluble-P within the rhizosphere, which is the zone that surrounds the plant roots. PSM's can be used as seed- or soil-inocula to increase plant P-uptake and the overall growth. A total of 162 PSM's were isolated from the rhizosphere of wheat plants excavated from different fields located along a 75 km part of a highway in Turkey. The mean, the standart deviation, and the median for solubilized-P (ppm) in a 24 h culture in a tricalcium phosphate broth were 681, 427, and 400 for glucose; 358, 266, and 236 for sucrose; and 102, 117, and 50 for starch, respectively. There was not a linear relationship between the phosphate solubilized in the liquid cultures and the solubilization index obtained in the Pikovskaya's agar. Nine isolates representing both weak and strong solubilizers [Bacillus megaterium (5), Bacillus pumilis (1), Pseudomonas syringae pv. phaseolica (1), Pseudomonas fluorescens (1), Arthrobacter aurescens (1) as determined by the 16S rRNA gene sequence analysis] were further studied in a five day incubation. Pseudomonas syringae pv. phaseolica solubilized statistically (P<0.05) higher phosphate (409 ppm) than all the other strains did. There was not a statistically significant (P<0.05) difference in solubilized-P among the Bacillus strains. The pH of the medium fell to the levels between 4 and 5 from the initial neutrality. The phosphate solubilizing strains variably produced gluconic, 2-keto-D-gluconic, glycolic, acetic and butyric acids. The organic acids produced by these microorganisms seem to be the major source of phosphate solubilization in vitro.

  15. Solubilization of proteins: the importance of lysis buffer choice.

    PubMed

    Peach, Mandy; Marsh, Noelle; Miskiewicz, Ewa I; MacPhee, Daniel J

    2015-01-01

    The efficient extraction of proteins of interest from cells and tissues is not always straightforward. Here we demonstrate the differences in extraction of the focal adhesion protein Kindlin-2 from choriocarcinoma cells using NP-40 and RIPA lysis buffer. Furthermore, we demonstrate the use of a more denaturing urea/thiourea lysis buffer for solubilization, by comparing its effectiveness for solubilization of small heat-shock proteins from smooth muscle with the often utilized RIPA lysis buffer. Overall, the results demonstrate the importance of establishing the optimal lysis buffer for specific protein solubilization within the experimental workflow.

  16. Pesticide tolerant and phosphorus solubilizing Pseudomonas sp. strain SGRAJ09 isolated from pesticides treated Achillea clavennae rhizosphere soil.

    PubMed

    Rajasankar, R; Manju Gayathry, G; Sathiavelu, A; Ramalingam, C; Saravanan, V S

    2013-05-01

    In this study, an attempt was made to identify an effective phosphate solubilizing bacteria from pesticide polluted field soil. Based on the formation of solubilization halo on Pikovskaya's agar, six isolates were selected and screened for pesticide tolerance and phosphate (P) solubilization ability through liquid assay. The results showed that only one strain (SGRAJ09) obtained from Achillea clavennae was found to tolerate maximum level of the pesticides tested and it was phylogenetically identified as Pseudomonas sp. It possessed a wide range of pesticide tolerance, ranging from 117 μg mL(-1) for alphamethrin to 2,600 μg mL(-1) for endosulfan. The available P concentrations increased with the maximum and double the maximum dose of monocrotophos and imidacloprid, respectively. On subjected to FT-IR and HPLC analysis, the presence of organic acids functional group in the culture broth and the production of gluconic acid as dominant acid aiding the P solubilization were identified. On comparison with control broth, monocrotophos and imidacloprid added culture broth showed quantitatively high organic acids production. In addition to gluconic acid production, citric and acetic acids were also observed in the pesticide amended broth. Furthermore, the Pseudomonas sp. strain SGRAJ09 possessed all the plant growth promoting traits tested. In presence of monocrotophos and imidacloprid, its plant growth promoting activities were lower than that of the pesticides unamended treatment.

  17. Cold-adapted and rhizosphere-competent strain of Rahnella sp. with broad-spectrum plant growth-promotion potential.

    PubMed

    Vyas, Pratibha; Joshi, Robin; Sharma, K C; Rahi, Praveen; Gulati, Ashu; Gulati, Arvind

    2010-12-01

    A phosphate-solubilizing bacterial strain isolated from Hippophae rhamnoides rhizosphere was identified as Rahnella sp. based on its phenotypic features and 16S rRNA gene sequence. The bacterial strain showed the growth characteristics of a cold-adapted psychrotroph, with the multiple plant growth-promoting traits of inorganic and organic phosphate solubilization, 1-aminocyclopropane-1- carboxylate-deaminase activity, ammonia generation, and siderophore production. The strain also produced indole- 3-acetic acid, indole-3-acetaldehyde, indole-3-acetamide, indole-3-acetonitrile, indole-3-lactic acid, and indole-3- pyruvic acid in tryptophan-supplemented nutrient broth. Gluconic, citric and isocitric acids were the major organic acids detected during tricalcium phosphate solubilization. A rifampicin-resistant mutant of the strain exhibited high rhizosphere competence without disturbance to the resident microbial populations in pea rhizosphere. Seed bacterization with a charcoal-based inoculum significantly increased growth in barley, chickpea, pea, and maize under the controlled environment. Microplot testing of the inoculum at two different locations in pea also showed significant increase in growth and yield. The attributes of coldtolerance, high rhizosphere competence, and broad-spectrum plant growth-promoting activity exhibited the potential of Rahnella sp. BIHB 783 for increasing agriculture productivity.

  18. Optimization of inclusion body solubilization and renaturation of recombinant human growth hormone from Escherichia coli.

    PubMed

    Patra, A K; Mukhopadhyay, R; Mukhija, R; Krishnan, A; Garg, L C; Panda, A K

    2000-03-01

    Recombinant human growth hormone (r-hGH) was expressed in Escherichia coli as inclusion bodies. In 10 h of fed-batch fermentation, 1.6 g/L of r-hGH was produced at a cell concentration of 25 g dry cell weight/L. Inclusion bodies from the cells were isolated and purified to homogeneity. Various buffers with and without reducing agents were used to solubilize r-hGH from the inclusion bodies and the extent of solubility was compared with that of 8 M urea as well as 6 M Gdn-HCl. Hydrophobic interactions as well as ionic interactions were found to be the dominant forces responsible for the formation of r-hGH inclusion bodies during its high-level expression in E. coli. Complete solubilization of r-hGH inclusion bodies was observed in 100 mM Tris buffer at pH 12.5 containing 2 M urea. Solubilization of r-hGH inclusion bodies in the presence of low concentrations of urea helped in retaining the existing native-like secondary structures of r-hGH, thus improving the yield of bioactive protein during refolding. Solubilized r-hGH in Tris buffer containing 2 M urea was found to be less susceptible to aggregation during buffer exchange and thus was refolded by simple dilution. The r-hGH was purified by use of DEAE-Sepharose ion-exchange chromatography and the pure monomeric r-hGH was finally obtained by using size-exclusion chromatography. The overall yield of the purified monomeric r-hGH was approximately 50% of the initial inclusion body proteins and was found to be biologically active in promoting growth of rat Nb2 lymphoma cell lines.

  19. Solubilization of 2-phenylethanol by dodecyldimethylamine oxide in aqueous solution

    SciTech Connect

    Uchiyama, Hirotaka; Christian, S.D.; Scamehorn, J.F. ); Abe, Masahiko; Ogino, Keizo )

    1991-01-01

    The solubilization of 2-phenylethanol (PEA) was measured over a wide range of solute activities and pH values by using dodecyldimethylamine oxide (DDAO) as the surfactant. The DDAO in micellar form is all cationic (protonated) at low pH and all nonionic at high pH. At intermediate pH levels, the DDAO forms mixed micelles containing both the cationic and nonionic forms of surfactant. Thus, measurement of the solubilization of PEA as a function of pH produces solubilization data as a function of mixed micelle composition for this amphoteric surfactant. The solubilization equilibrium constant was found to decrease with increasing mole fraction of PEA in the micelle for all pH values and to be less in the mixed micelles than in either pure cationic or pure nonionic micelles. This latter effect could be due to the hydrophilic region of the mixed micelle being more compact than that of the single-component micelles.

  20. Polydopamine as a new modification material to accelerate startup and promote anode performance in microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Du, Qing; An, Jingkun; Li, Junhui; Zhou, Lean; Li, Nan; Wang, Xin

    2017-03-01

    The bacterial anode material is important to the performance of microbial fuel cells (MFCs) because its characteristics affect the biofilm formation and extracellular electron transfer. Here we find that a superhydrophilic semiconductor, polydopamine (PDA), is an effective modification material for the anode to accelerate startup and improve power density. When the activated carbon anode is added with 50% (wt.) PDA, the startup time is 14% shorter than the control (from 88 h to 76 h), with a 31% increase in maximum power density from 613 ± 9 to 803 ± 6 mW m-2, and the Columbic efficiency increases from 19% to 48%. These can be primarily attributed to the abundant functional groups (such as amino group, and catechol functions) introduced by PDA that improve hydrophilicity and extracellular electron transfer. PDA also increases proportions of Proteobacteria and Firmicutes families, indicating that PDA has a selective effect on anode microbial community. Our findings provide a new approach to accelerate anode biofilm formation and enhance MFC power output by modification of biocompatible PDA.

  1. Microbial Community Dynamics and Response to Plant Growth-Promoting Microorganisms in the Rhizosphere of Four Common Food Crops Cultivated in Hydroponics.

    PubMed

    Sheridan, C; Depuydt, P; De Ro, M; Petit, C; Van Gysegem, E; Delaere, P; Dixon, M; Stasiak, M; Aciksöz, S B; Frossard, E; Paradiso, R; De Pascale, S; Ventorino, V; De Meyer, T; Sas, B; Geelen, D

    2017-02-01

    Plant growth promoting microorganisms (PGPMs) of the plant root zone microbiome have received limited attention in hydroponic cultivation systems. In the framework of a project aimed at the development of a biological life support system for manned missions in space, we investigated the effects of PGPMs on four common food crops (durum and bread wheat, potato and soybean) cultivated in recirculating hydroponic systems for a whole life cycle. Each crop was inoculated with a commercial PGPM mixture and the composition of the microbial communities associated with their root rhizosphere, rhizoplane/endosphere and with the recirculating nutrient solution was characterised through 16S- and ITS-targeted Illumina MiSeq sequencing. PGPM addition was shown to induce changes in the composition of these communities, though these changes varied both between crops and over time. Microbial communities of PGPM-treated plants were shown to be more stable over time. Though additional development is required, this study highlights the potential benefits that PGPMs may confer to plants grown in hydroponic systems, particularly when cultivated in extreme environments such as space.

  2. Microbial acquisition of iron from ferric iron bearing minerals

    SciTech Connect

    Hersman, L.E.; Sposito, G.

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Iron is a universal requirement for all life forms. Although the fourth most abundant element in the geosphere, iron is virtually insoluble at physiological pH in oxidizing environments, existing mainly as very insoluble oxides and hydroxides. Currently it is not understood how iron is solubilized and made available for biological use. This research project addressed this topic by conducting a series of experiments that utilized techniques from both soil microbiology and mineral surface geochemistry. Microbiological analysis consisted of the examination of metabolic and physiological responses to mineral iron supplements. At the same time mineral surfaces were examined for structural changes brought about by microbially mediated dissolution. The results of these experiments demonstrated that (1) bacterial siderophores were able to promote the dissolution of iron oxides, (2) that strict aerobic microorganisms may use anaerobic processes to promote iron oxide dissolution, and (3) that it is possible to image the surface of iron oxides undergoing microbial dissolution.

  3. Mechanisms for solubilization of various insoluble phosphates and activation of immobilized phosphates in different soils by an efficient and salinity-tolerant Aspergillus niger strain An2.

    PubMed

    Li, Xiaolong; Luo, Lijin; Yang, Jinshui; Li, Baozhen; Yuan, Hongli

    2015-03-01

    Mechanisms for solubilization of different types of phosphates and activation of immobilized phosphates in different types of soils by an efficient fungal strain An2 were explored and evaluated in this study. An2 was isolated from a Chinese cabbage rhizosphere soil and identified as Aspergillus niger. It could fast release up to 1722, 2066, and 2356 mg L(-1) of soluble phosphorus (P) from 1 % Ca3(PO4)2, Mg3(PO4)2, and AlPO4 (Ca-P, Mg-P, and Al-P) and 215 and 179 mg L(-1) from 0.5 % FePO4 and rock phosphate (Fe-P and RP), respectively. HPLC assay demonstrated that An2 mainly secreted oxalic acid to solubilize Ca-P, Mg-P, Al-P, and Fe-P whereas secreted tartaric acid to solubilize RP. Furthermore, An2 could tolerate salinity up to 4 % NaCl without impairing its phosphate-solubilizing ability. The simulation experiments validated that An2 was able to effectively activate immobilized phosphates in general calcareous, acidic, as well as saline-alkali soils with high total P content. This study shows new insights into the mechanisms for microbial solubilization of different types of phosphates and supports the future application of strain An2 in different types of soils to effectively activate P for plants.

  4. Auxins as one of the factors of plant growth improvement by plant growth promoting rhizobacteria.

    PubMed

    Ahmed, Ambreen; Hasnain, Shahida

    2014-01-01

    Plant growth promoting rhizobacteria (PGPR) promote plant growth by various mechanisms such as phytohormone production, enhanced water and nutrient uptake, improved nitrogen availability in the soil, production of ACC-deaminase for ethylene breakdown, phosphate solubilization, siderophore production etc. Microbial auxin production is the major factor not only responsible for strengthening the plant-microbe relationship but it also promotes plant growth and development in a positive manner. Thus, bacterial auxin production potential can be exploited for plant growth improvement that may be effective in reducing the hazardous effects of chemical fertilizers on the ecosystem used to obtain higher yields. The present review gives a better understanding of various factors and mechanisms involved in auxin production by PGPR that may be helpful in proper exploitation of these natural resources in a beneficial way.

  5. Solubilization of a dendrimer into a microemulsion.

    PubMed

    Nir, Ido; Aserin, Abraham; Libster, Dima; Garti, Nissim

    2010-12-23

    The present work investigates, for the first time, a system comprising a dendrimer incorporated into the water core of water-in-oil (W/O) microemulsion (ME). A second generation (G-2) poly(propyleneimine) dendrimer (PPI) was solubilized into W/O ME composed of AOT (sodium bis(2-ethylhexyl)sulfosuccinate), heptane, and water. Such a model system possessing the benefits of both dendrimers and ME, can potentially offer superior control of drug administration. The localization of PPI within the system, its specific interactions with the components of the carrier, and its effect on the ME structure was explored by SAXS, DSC, ATR-FTIR, and electrical conductivity measurements. Considerable water binding by PPI, accompanied by partial dehydration of AOT polar heads, was detected by ATR-FTIR and DSC analysis, suggesting that PPI acted as a "water pump". In addition, SAXS measurements showed periodicity increase and disordering of the droplets. Hence, localization of PPI within the core and interfacial regions of the droplets was assumed. Direct electrostatic interactions between PPI and the sulfonate group were not noticed, since the dendrimer molecules were mostly not protonated in the current basic environment at pH 12. However, slight hydrogen bonding between PPI and the S=O groups allowed the dendrimer to behave as a "spacer" between sodium and sulfonate ions. This affected the electrical conductivity behavior of the system, revealing that PPI favored the percolation process. Most likely, PPI decreased the rigidity of the interfacial layer, facilitating the diffusion of sodium ions through the channels. The characterized model system can be advantageously utilized to design specific delivery vehicles, allowing administration of dendrimers as a therapeutic agent from host MEs.

  6. Solubilization and fractionation of paired helical filaments.

    PubMed

    González, P J; Correas, I; Avila, J

    1992-09-01

    Paired helical filaments isolated from brains of two different patients with Alzheimer's disease were extensively treated with the ionic detergent, sodium dodecyl sulphate. Filaments were solubilized at different extents, depending on the brain examined, thus suggesting the existence of two types of paired helical filaments: sodium dodecyl sulphate-soluble and insoluble filaments. In the first case, the number of structures resembling paired helical filaments greatly decreased after the detergent treatment, as observed by electron microscopy. Simultaneously, a decrease in the amount of sedimentable protein was also observed upon centrifugation of the sodium dodecyl sulfate-treated paired helical filaments. A sodium dodecyl sulphate-soluble fraction was isolated as a supernatant after low-speed centrifugation of the sodium dodecyl sulphate-treated paired helical filaments. The addition of the non-ionic detergent Nonidet-P40 to this fraction resulted in the formation of paired helical filament-like structures. When the sodium dodecyl sulphate-soluble fraction was further fractionated by high-speed centrifugation, three subfractions were observed: a supernatant, a pellet and a thin layer between these two subfractions. No paired helical filaments were observed in any of these subfractions, even after addition of Nonidet P-40. However, when they were mixed back together, the treatment with Nonidet P-40 resulted in the visualization of paired helical filament-like structures. These results suggest that at least two different components are needed for the reconstitution of paired helical filaments as determined by electron microscopy. The method described here may allow the study of the components involved in the formation of paired helical filaments and the identification of possible factors capable of blocking this process.

  7. Using pig manure to promote fermentation of sugarcane molasses alcohol wastewater and its effects on microbial community structure.

    PubMed

    Shen, Peihong; Han, Fei; Su, Shuquan; Zhang, Junya; Chen, Zhineng; Li, Junfang; Gan, Jiayi; Feng, Bin; Wu, Bo

    2014-03-01

    Molasses alcohol wastewater (MAW) is difficult to be bio-treated and converted into biogas. In this study, MAW mixed with pig manure (PM) in different ratios was co-digested. Biogas production, chemical oxygen demand (COD) removal and the structure of microbial communities were monitored in the process. Our results showed that under the optimal COD ratio of PM:MAW (1.0:1.5), CODremoval and biogas yield were the highest. And in fermentation tanks with different PM to MAW ratios, the structure and composition of bacterial communities varied in the early and late stage. Furthermore, the type of main bacterial operational taxonomic units (OTUs) have no differences, yet the relative abundance of OTUs varied. The current research showed that there was a good potential to the use of PM as a co-digested material to anaerobic treatment of MAW and provided references for further improving bio-treatment of MAW.

  8. Discarded oranges and brewer's spent grains as promoting ingredients for microbial growth by submerged and solid state fermentation of agro-industrial waste mixtures.

    PubMed

    Aggelopoulos, Theodoros; Bekatorou, Argyro; Pandey, Ashok; Kanellaki, Maria; Koutinas, Athanasios A

    2013-08-01

    The exploitation of various agro-industrial wastes for microbial cell mass production of Kluyveromyces marxianus, kefir, and Saccharomyces cerevisiae is reported in the present investigation. Specifically, the promotional effect of whole orange pulp on cell growth in mixtures consisting of cheese whey, molasses, and potato pulp in submerged fermentation processes was examined. A 2- to 3-fold increase of cell mass was observed in the presence of orange pulp. Likewise, the promotional effect of brewer's spent grains on cell growth in solid state fermentation of mixtures of whey, molasses, potato pulp, malt spent rootlets, and orange pulp was examined. The cell mass was increased by 3-fold for K. marxianus and 2-fold for S. cerevisiae in the presence of these substrates, proving their suitability for single-cell protein production without the need for extra nutrients. Cell growth kinetics were also studied by measurements of cell counts at various time intervals at different concentrations of added orange pulp. The protein content of the fermented substrates was increased substantially, indicating potential use of mixed agro-industrial wastes of negligible cost, as protein-enriched livestock feed, achieving at the same time creation of added value and waste minimization.

  9. Trace heavy metal ions promoted extracellular electron transfer and power generation by Shewanella in microbial fuel cells.

    PubMed

    Xu, Yu-Shang; Zheng, Tao; Yong, Xiao-Yu; Zhai, Dan-Dan; Si, Rong-Wei; Li, Bing; Yu, Yang-Yang; Yong, Yang-Chun

    2016-07-01

    Although microbial fuel cells (MFCs) is considered as one of the most promising technology for renewable energy harvesting, low power output still accounts one of the bottlenecks and limits its further development. In this work, it is found that Cu(2+) (0.1μgL(-1)-0.1mgL(-1)) or Cd(2+) (0.1μgL(-1)-1mgL(-1)) significantly improve the electricity generation in MFCs. The maximum power output achieved with trace level of Cu(2+) (∼6nM) or Cd(2+) (∼5nM) is 1.3 times and 1.6 times higher than that of the control, respectively. Further analysis verifies that addition of Cu(2+) or Cd(2+) effectively improves riboflavin production and bacteria attachment on the electrode, which enhances bacterial extracellular electron transfer (EET) in MFCs. These results unveil the mechanism for power output enhancement by Cu(2+) or Cd(2+) addition, and suggest that metal ion addition should be a promising strategy to enhance EET as well as power generation of MFCs.

  10. Solubilization and biodegradation of hydrophobic organic compounds in soil/aqueous systems with nonionic surfactants

    SciTech Connect

    Edwards, D.A.; Laha, S.; Liu, Zhongbao; Luthy, R.G.

    1992-01-01

    Nonionic surfactants may strongly interact with hydrophobic organic compounds (HOCs), soil, and microorganisms in soil/aqueous systems. These interactions affect the potential for surfactant-facilitated HOC transport in soil and groundwater systems, and the feasibility of engineered surfactant cleanup of contaminated sites (McCarthy and Wober, 1991). At sufficiently high bulk liquid concentrations at 25 C, most nonionic surfactants form regular micelles in single-phase solutions, whereas certain surfactants, such as C{sub 12}E{sub 4}, may form bilayer lamellae or other types of aggregates in more complex two-phase solutions. The critical concentrations for the onset of micelle and aggregate formation are termed the critical micelle concentration (CMC) and the critical aggregation concentration (CAC), respectively. Important changes occur in surfactant sorption, surfactant solubilization of HOCs, and microbial mineralization of HOCs in the presence of nonionic surfactants at or near these critical surfactant concentrations.

  11. Solubilization and biodegradation of hydrophobic organic compounds in soil/aqueous systems with nonionic surfactants

    SciTech Connect

    Edwards, D.A.; Laha, S.; Liu, Zhongbao; Luthy, R.G.

    1992-05-01

    Nonionic surfactants may strongly interact with hydrophobic organic compounds (HOCs), soil, and microorganisms in soil/aqueous systems. These interactions affect the potential for surfactant-facilitated HOC transport in soil and groundwater systems, and the feasibility of engineered surfactant cleanup of contaminated sites (McCarthy and Wober, 1991). At sufficiently high bulk liquid concentrations at 25 C, most nonionic surfactants form regular micelles in single-phase solutions, whereas certain surfactants, such as C{sub 12}E{sub 4}, may form bilayer lamellae or other types of aggregates in more complex two-phase solutions. The critical concentrations for the onset of micelle and aggregate formation are termed the critical micelle concentration (CMC) and the critical aggregation concentration (CAC), respectively. Important changes occur in surfactant sorption, surfactant solubilization of HOCs, and microbial mineralization of HOCs in the presence of nonionic surfactants at or near these critical surfactant concentrations.

  12. Solubilization and reconstitution of vesicular stomatitis virus envelope using octylglucoside.

    PubMed Central

    Paternostre, M; Viard, M; Meyer, O; Ghanam, M; Ollivon, M; Blumenthal, R

    1997-01-01

    Reconstituted vesicular stomatitis virus envelopes or virosomes are formed by detergent removal from solubilized intact virus. We have monitored the solubilization process of the intact vesicular stomatitis virus by the nonionic surfactant octylglucoside at various initial virus concentrations by employing turbidity measurements. This allowed us to determine the phase boundaries between the membrane and the mixed micelles domains. We have also characterized the lipid and protein content of the solubilized material and of the reconstituted envelope. Both G and M proteins and all of the lipids of the envelope were extracted by octylglucoside and recovered in the reconstituted envelope. Fusion activity of the virosomes tested either on Vero cells or on liposomes showed kinetics and pH dependence similar to those of the intact virus. Images FIGURE 4 PMID:9083672

  13. Expression, Solubilization, and Purification of Bacterial Membrane Proteins.

    PubMed

    Jeffery, Constance J

    2016-02-02

    Bacterial integral membrane proteins play many important roles, including sensing changes in the environment, transporting molecules into and out of the cell, and in the case of commensal or pathogenic bacteria, interacting with the host organism. Working with membrane proteins in the lab can be more challenging than working with soluble proteins because of difficulties in their recombinant expression and purification. This protocol describes a standard method to express, solubilize, and purify bacterial integral membrane proteins. The recombinant protein of interest with a 6His affinity tag is expressed in E. coli. After harvesting the cultures and isolating cellular membranes, mild detergents are used to solubilize the membrane proteins. Protein-detergent complexes are then purified using IMAC column chromatography. Support protocols are included to help select a detergent for protein solubilization and for use of gel filtration chromatography for further purification.

  14. Carrageenans solubilize asymmetric acetylcholinesterase from nicotinic cholinergic synapses.

    PubMed

    von Bernhardi, R; Ayal, H; Inestrosa, N C

    1990-01-01

    1. Acetylcholinesterase (AChE) catalyzes the hydrolysis of acetylcholine at cholinergic synapses in both vertebrate and invertebrates organisms. 2. The asymmetric synaptic AChE is attached to the extracellular matrix (ECM) of the neuromuscular junction through heparin sulphate proteoglycans (HSPGs). 3. It has been shown previously that heparin-like glycosaminoglycans (GAGs) can solubilize this enzyme from the cholinergic synapses. 4. The present paper describes the solubilization of asymmetric AChE by different marine macroalgal polysaccharides, called carrageenans. 5. Important differences were found among all the carrageenans tested; they released 15-50% of the total AChE activity normally solubilized by heparin. 6. Carrageenans extracted from tetrasporic stages of Iridaea ciliata and I. membranacea were always better extracting agents than those from the cystocarpic stages of these algae, suggesting that lambda-like carrageenans are involved. 7. This hypothesis was confirmed by extracting AChE with purified carrageenans.

  15. Solubilization of a membrane protein by combinatorial supercharging.

    PubMed

    Hajduczki, Agnes; Majumdar, Sudipta; Fricke, Marie; Brown, Isola A M; Weiss, Gregory A

    2011-04-15

    Hydrophobic and aggregation-prone, membrane proteins often prove too insoluble for conventional in vitro biochemical studies. To engineer soluble variants of human caveolin-1, a phage-displayed library of caveolin variants targeted the hydrophobic intramembrane domain with substitutions to charged residues. Anti-selections for insolubility removed hydrophobic variants, and positive selections for binding to the known caveolin ligand HIV gp41 isolated functional, folded variants. Assays with several caveolin binding partners demonstrated the successful folding and functionality by a solubilized, full-length caveolin variant selected from the library. This caveolin variant allowed assay of the direct interaction between caveolin and cavin. Clustered along one face of a putative helix, the solubilizing mutations suggest a structural model for the intramembrane domain of caveolin. The approach provides a potentially general method for solubilization and engineering of membrane-associated proteins by phage display.

  16. Artificial citrate operon and Vitreoscilla hemoglobin gene enhanced mineral phosphate solubilizing ability of Enterobacter hormaechei DHRSS.

    PubMed

    Yadav, Kavita; Kumar, Chanchal; Archana, G; Kumar, G Naresh

    2014-10-01

    Mineral phosphate solubilization by bacteria is mediated through secretion of organic acids, among which citrate is one of the most effective. To overproduce citrate in bacterial systems, an artificial citrate operon comprising of genes encoding NADH-insensitive citrate synthase of E. coli and Salmonella typhimurium sodium-dependent citrate transporter was constructed. In order to improve its mineral phosphate solubilizing (MPS) ability, the citrate operon was incorporated into E. hormaechei DHRSS. The artificial citrate operon transformant secreted 7.2 mM citric acid whereas in the native strain, it was undetectable. The transformant released 0.82 mM phosphate in flask studies in buffered medium containing rock phosphate as sole P source. In fermenter studies, similar phenotype was observed under aerobic conditions. However, under microaerobic conditions, no citrate was detected and P release was not observed. Therefore, an artificial citrate gene cluster containing Vitreoscilla hemoglobin (vgb) gene under its native promoter, along with artificial citrate operon under constitutive tac promoter, was constructed and transformed into E. hormaechei DHRSS. This transformant secreted 9 mM citric acid under microaerobic conditions and released 1.0 mM P. Thus, incorporation of citrate operon along with vgb gene improves MPS ability of E. hormaechei DHRSS under buffered, microaerobic conditions mimicking rhizospheric environment.

  17. Center of Microbial Oceanography Research and Education (C-MORE) Initiatives Toward Promoting Diversity in the Ocean Sciences

    NASA Astrophysics Data System (ADS)

    Bruno, B. C.

    2007-05-01

    The ocean sciences suffer from a lack of diversity, particularly among indigenous peoples, despite the fact that indigenous peoples often have deep, cultural knowledge about the marine environment. Nowhere is this inequity more glaring than in Hawaii. Traditional knowledge in marine science enabled Native Hawaiians and Pacific Islanders (NHPI) to become world leaders in transpacific canoe voyaging, aquaculture, and fisheries. Yet today, NHPI are severely underrepresented in the ocean sciences (and in STEM fields in general) at all levels of education and employment. When compared to other ethnic and racial groups in Hawaii, NHPI students as a group have among the poorest educational performance, indicated in part by underrepresentation in college enrolment and pre-college gifted and talented programs, as well as overrepresentation in eligibility for special education and free and reduced lunch programs. The Center of Microbial Oceanography Research and Education (C-MORE), a NSF-funded, multi-institutional Science and Technology Center based at the University of Hawai (UH), is determined to address this inequity. C- MORE is committed to increasing diversity in the ocean sciences, particularly among NHPI, at all levels of education and research. Our approach is to work with existing programs with a track record of increasing diversity among NHPI. We are currently developing culturally relevant materials including educational games for K-12 students, mentorships for high school and community college students, and laboratory and shipboard experiences for teachers and undergraduates in partnership with minority-serving organizations. Some of our main partners are EPSCoR (Experimental Program to Stimulate Competitive Research), Ka `Imi `Ike (an NSF- funded program to recruit and retain NHPI undergraduates in geosciences), Upward Bound (an enrichment program for economically disadvantaged high school students which includes intensive summer courses), the UH Center on

  18. T(H)17 cells promote microbial killing and innate immune sensing of DNA via interleukin 26.

    PubMed

    Meller, Stephan; Di Domizio, Jeremy; Voo, Kui S; Friedrich, Heike C; Chamilos, Georgios; Ganguly, Dipyaman; Conrad, Curdin; Gregorio, Josh; Le Roy, Didier; Roger, Thierry; Ladbury, John E; Homey, Bernhard; Watowich, Stanley; Modlin, Robert L; Kontoyiannis, Dimitrios P; Liu, Yong-Jun; Arold, Stefan T; Gilliet, Michel

    2015-09-01

    Interleukin 17-producing helper T cells (T(H)17 cells) have a major role in protection against infections and in mediating autoimmune diseases, yet the mechanisms involved are incompletely understood. We found that interleukin 26 (IL-26), a human T(H)17 cell-derived cytokine, is a cationic amphipathic protein that kills extracellular bacteria via membrane-pore formation. Furthermore, T(H)17 cell-derived IL-26 formed complexes with bacterial DNA and self-DNA released by dying bacteria and host cells. The resulting IL-26-DNA complexes triggered the production of type I interferon by plasmacytoid dendritic cells via activation of Toll-like receptor 9, but independently of the IL-26 receptor. These findings provide insights into the potent antimicrobial and proinflammatory function of T(H)17 cells by showing that IL-26 is a natural human antimicrobial that promotes immune sensing of bacterial and host cell death.

  19. Water-solubilization and functionalization of semiconductor quantum dots.

    PubMed

    Tyrakowski, Christina M; Isovic, Adela; Snee, Preston T

    2013-01-01

    Semiconductor quantum dots (QDs) are highly fluorescent nanocrystals that have abundant potential for uses in biological imaging and sensing. However, the best materials are synthesized in hydrophobic surfactants that prevent direct aqueous solubilization. While several methods have been developed to impart water-solubility, an aqueous QD dispersion has no inherent useful purpose and must be functionalized further. Due to the colloidal nature of QD dispersions, traditional methods of chemical conjugation in water either have low yields or cause irreversible precipitation of the sample. Here, we describe several methods to water-solubilize QDs and further functionalize the materials with chemical and/or biological vectors.

  20. [Solubilization Specificities Interferon beta-1b from Inclusion Bodies].

    PubMed

    Zhuravko, A S; Kononova, N V; Bobruskin, A I

    2015-01-01

    A new solubilization method of recombinant interferon beta-1b (IFNβ-1b) from the inclusion bodies was developed. This method allows to extract the target protein selectively in the solutions of different alcohols, such as ethanol, propanol and isopropanol. It was shown that the more effective IFNβ-1b solubilization was achieved in the 55% propanol solution. This method allowed to extract the target protein from inclusion bodies around 85-90%, and significantly reduced Escherichia coli content in the solubilizate, in comparison with standard methods.

  1. Cosolvent-induced solubilization of hydrophobic compounds into water

    SciTech Connect

    Banerjee, S.; Yalkowsky, S.H.

    1988-10-01

    The solubilization of toluene into water by propylene glycol and methanol was measured by a novel liquid chromatographic procedure. The relationship between solubilization and cosolvent content is linear up to 10-20 vol % of cosolvent, beyond which conventional logarithmic behavior is observed. The point of departure from linearity is believed to signal the onset of interaction between the extended hydration shells of the cosolvent. For propylene glycol, the volume of this shell is about 500 mL/mol, and the solubility of toluene within the shell is about 1.3 times its solubility in pure water.

  2. Fermentation characteristics and microbial growth promoted by diets including two-phase olive cake in continuous fermenters.

    PubMed

    Moumen, A; Yáñez-Ruiz, D R; Martín-García, I; Molina-Alcaide, E

    2008-02-01

    Two-phase olive cake (2POC) is the by-product obtained from the so called 'two-phase' procedure to extract olive oil by mechanical methods. After the mechanical extraction the 2POC is dried and most of the remaining oil extracted by chemical means. The production of the crude by-product may reach more than 4 millions t/year in Spain (MAPA, 2003), most of it in areas (Southeast) with shortage of pastures and conventional feeds for ruminants. Six continuous fermenters, inoculated with ruminal liquor from wethers or goats, were fed lucerne hay (LH); LH plus a concentrate including dried two-phase olive cake (LHCO) and; diet LHCO added with polyethylene glycol (LHCOP). The highest pH values and ammonia N (NH(3)-N) output were found in fermenters fed diet LH (6.19 and 6.35 for pH, and 53.7 and 68.9 mg NH(3)N/day, respectively, in fermentes inoculated with rumen liquor from sheep and goats) without differences due to the inoculum origin. The digestibility of carbohydrates (CHO) was affected (p < 0.001) by inoculum (67.0 and 58.8%, respectively, for goats and wethers) the lowest values being for diet LHCO (53.2 and 57.0% with inoculum from wethers and goats, respectively). The main volatile fatty acid (VFA) was acetic acid with higher (p < 0.01) values in fermenters with inoculum from goats than from wethers (80.2 and 63.0 mmol/day respectively). The efficiency of bacterial protein synthesis (EBS) was not different (p > 0.05) with inoculum from wethers and goats [26.4 and 28.1 and 35.2 and 33.5 g bacterial N/kg digested CHO, respectively, obtained by using diamino pimelic acid (DAPA) and purine bases (PB) as microbial markers]. The lowest (p < 0.05) values were found in fermenters fed diets LHCOP and LH, estimated, respectively, from DAPA and PB (21.9 and 29.0 g bacterial N/kg digested CHO). The substitution of a part of lucerne hay by a concentrate including dried 2POC does not seem to cause important differences in efficiency of VFA production. Results concerning

  3. Microbial conversion of coal

    SciTech Connect

    Bean, R.M. )

    1989-10-01

    The objectives of this project were to describe in detail the degradation of coals by fungi and microbes, to expand the range of applicability of the process to include new microbes and other coal types, to identify the means by which biosolubilization of coal is accomplished, and to explore means to enhance the rates and extent of coal bioconversion. The project was initiated in a response to the discovery by Dr. Martin Cohen at the University of Hartford, of a fungal strain of Coriolus versicolor that would render a solid coal substance, leonardite, into a liquid product. The project has identified the principal agent of leonardite solubilization as a powerful metal chelator, most likely a fungal-produced siderophore. Another nonlaccase enzyme has also been identified as a unique biosolubilizing agent produced by C. versicolor. Assays were developed for the quantitative determination of biological coal conversion, and for the determination of potency of biosolubilizing agent. Screening studies uncovered several microbial organisms capable of coal biodegradation, and led to the discovery that prolonged heating in air at the moderate temperature of 150{degree}C allowed the biodegradation of Illinois {number sign}6 coal to material soluble in dilute base. Chemical studies showed that leonardite biosolubilization was accompanied by relatively small change in composition, while solubilization of Illinois {number sign}6 coal involves considerable oxidation of the coal. 24 refs., 32 figs., 27 tabs.

  4. Survival of Listeria innocua in rainbow trout protein recovered by isoelectric solubilization and precipitation with acetic and citric acids.

    PubMed

    Otto, R A; Paker, I; Bane, L; Beamer, S; Jaczynski, J; Matak, K E

    2011-08-01

    During mechanical fish processing, a substantial amount of protein is discarded as by-products. Isoelectric solubilization and precipitation (ISP) is a process that uses extreme pH shifts to solubilize and precipitate protein from by-products to recover previously discarded protein. Typically, strong acids are used for pH reduction, but these acids do not have a pasteurization effect (6 log reduction) on bacterial load; therefore, organic acids were used during ISP processing to test the impact on Listeria innocua concentrations. Headed and gutted rainbow trout (Oncorhynchus mykiss) were inoculated with L. innocua, homogenized, and brought to the target pH with granular citric acid (pH 2.0 and 2.5) or glacial acetic acid (pH 3.0 and 3.5). Proteins were solubilized for 10 min at 4°C, and insoluble components (e.g., skin and insoluble protein) were removed by centrifugation. The remaining solution was pH shifted to the protein isoelectric point (pH 5.5) with sodium hydroxide, and precipitated protein was separated from the water. Microbial cells for each component (proteins, insolubles, and water) were enumerated on modified Oxford agar (MOX) and tryptic soy agar with 6% yeast extract (TSAYE). The sums of the surviving cells from each component were compared with the initial inoculum levels. No significant differences were observed between results obtained from TSAYE and from MOX (P > 0.05). Significant reductions in microbial populations were detected, regardless of pH or acid type (P < 0.05). The greatest reduction was at pH 3.0 with glacial acetic acid, resulting in a mean reduction of 6.41 log CFU/g in the recovered protein and 5.88 log CFU/g in the combined components. These results demonstrate the antimicrobial potential of organic acids in ISP processing.

  5. Synergism between Phyllobacterium sp. (N(2)-fixer) and Bacillus licheniformis (P-solubilizer), both from a semiarid mangrove rhizosphere.

    PubMed

    Rojas, A; Holguin, G; Glick, B R.; Bashan, Y

    2001-04-01

    Mangrove seedlings were treated with a mixture of two bacterial species, the slow-growing, N(2)-fixing bacterium Phyllobacterium sp. and the fast-growing, phosphate-solubilizing bacterium Bacillus licheniformis, both isolated from the rhizosphere from black, white, and red mangroves of a semiarid zone. Nitrogen fixation and phosphate solubilization increased when the mixture was used compared to the effects observed when adding individual cultures, notwithstanding that there was no increase in bacterial multiplication under these conditions. Inoculation of black mangrove seedlings in artificial seawater showed the mixture performed somewhat better than inoculation of the individual bacterium; more leaves were developed and higher levels of (15)N were incorporated into the leaves, although the total nitrogen level decreased. This study demonstrates that interactions between individual components of the rhizosphere of mangroves should be considered when evaluating these bacteria as plant growth promoters.

  6. Solubilized cytochrome c oxidase from Paracoccus denitrificans is a monomer.

    PubMed

    Ludwig, B; Grabo, M; Gregor, I; Lustig, A; Regenass, M; Rosenbusch, J P

    1982-05-25

    Cytochrome c oxidase purified from the bacterium Paracoccus denitrificans was analyzed by analytical ultracentrifugation. In the detergent octyltetra/pentaoxyethylene (C8E45), the isolated enzyme exhibits a molecular weight of 79,000 to 84,000. The detergent-solubilized enzyme is thus a monomer which contains one copy of each of the two subunits.

  7. Food volatile compounds facilitating HII mesophase formation: solubilization and stability.

    PubMed

    Amar-Zrihen, Natali; Aserin, Abraham; Garti, Nissim

    2011-05-25

    Four lipophilic food volatile molecules of different chemical characteristics, phenylacetaldehyde, 2,6-dimethyl-5-heptenal, linalool, and trans-4-decenal, were solubilized into binary mixtures of monoolein/water, facilitating the formation of reverse hexagonal (H(II)) mesophases at room temperature without the need of solvents or triglycerides. Some of the flavor compounds are important building blocks of the hexagonal mesostructure, preventing phase transition with aging. The solubilization loads were relatively high: 12.6, 10.0, 12.6, and 10.0 wt % for phenylacetaldehyde, 2,6-dimethyl-5-heptenal, linalool, and trans-4-decenal, respectively. Phenylacetaldehyde formed mixtures of lamellar and cubic phases. Linalool, 2,6-dimethyl-5-heptenal, and trans-4-decenal induced structural shift from lamellar directly to H(II) mesophase, remaining stable at room temperature. Lattice parameters were found to increase with water content and to decrease with temperature and/or food volatile content. trans-4-Decenal produces more stable H(II) mesophase compared to linalool-loaded mesophase. At 40-60 °C, depending on the chemical structure and on the solubilization location of the food volatile compounds, the H(II) mesophase transforms to isotropic micellar phase, facilitating the release of the food volatile compounds. Molecular interactions suggest the existence of two consecutive stages in the solubilization process.

  8. Mechanisms for chelator stimulation of microbial Fe(III) -oxide reduction

    USGS Publications Warehouse

    Lovley, D.R.; Woodward, J.C.

    1996-01-01

    The mechanisms by which nitrilotriacetic acid (NTA) stimulated Fe(III) reduction in sediments from a petroleum-contaminated aquifer were investigated in order to gain insight into how added Fe(III) chelators stimulate the activity of hydrocarbon-degrading, Fe(III)-reducing microorganisms in these sediments, and how naturally occurring Fe(III) chelators might promote Fe(III) reduction in aquatic sediments. NTA solubilized Fe(III) from the aquifer sediments. NTA stimulation of microbial Fe(III) reduction did not appear to be the result of making calcium, magnesium, potassium, or trace metals more available to the microorganisms. Stimulation of Fe(III) reduction could not be attributed to NTA serving as a source of carbon or fixed nitrogen for Fe(III)-reducing bacteria as NTA was not degraded in the sediments. Studies with the Fe(III)-reducing microorganism, Geobacter metallireducens, and pure Fe(III)-oxide forms, demonstrated that NTA stimulated the reduction of a variety of Fe(III) forms, including highly crystalline Fe(III)-oxides such as goethite and hematite. The results suggest that NTA solubilization of insoluble Fe(III)-oxide is an important mechanism for the stimulation of Fe(III) reduction by NTA in aquifer sediments.

  9. Solubilization of simvastatin and phytosterols in a dilutable microemulsion system.

    PubMed

    Fisher, Sarah; Wachtel, Ellen J; Aserin, Abraham; Garti, Nissim

    2013-07-01

    The usual treatment of hypercholesterolemia includes a class of drugs known as statins (simvastatin among them), which inhibit the production of cholesterol. Another way of reducing cholesterol levels is with the use of phytosterols, which reduce the transport of exogenic cholesterol from the intestine into the blood stream. The two treatments can be combined, achieving an additive effect. However, both simvastatin and phytosterols are practically insoluble in water, and therefore their absorption and activity are low. Nanosized self-assembled structured liquid systems are modified microemulsions that present an alternative pathway for improving the bioavailability of poorly water-soluble drugs. The goal of this study was to solubilize the maximal quantity of both simvastatin and phytosterols in a single, fully dilutable microemulsion system. We constructed a water-dilutable liquid drug delivery system that includes sucrose monolaurate, propylene glycol, and oleyl lactate. This system exhibits high solubilization capacity for both simvastatin (7.0 wt%) and phytosterols (3.5 wt%) when each is solubilized separately in a water-free concentrate. When simvastatin and phytosterols were solubilized together at a wt ratio of 2.5:1, maximum solubilization was obtained with 4.7 wt% simvastatin and 1.9 wt% phytosterols. Structural and analytical methods were applied including rheology, DSC, SD-NMR, SAXS, and cryo-TEM. The water-free "concentrate" consisted of direct micelles for which propylene glycol served as the hydrophilic phase. Upon water dilution, the direct micelles appear to form "lipophilic compounds dispersed in hydrophilic continuous phase". The solubilizates are located in the droplet core and/or at the interface.

  10. Application of Potential Phosphate-Solubilizing Bacteria and Organic Acids on Phosphate Solubilization from Phosphate Rock in Aerobic Rice

    PubMed Central

    Jusop, Shamshuddin; Naher, Umme Aminun; Othman, Radziah; Razi, Mohd Ismail

    2013-01-01

    A study was conducted at Universiti Putra Malaysia to determine the effect of phosphate-solubilizing bacteria (PSB) and organic acids (oxalic & malic) on phosphate (P) solubilization from phosphate rock (PR) and growth of aerobic rice. Four rates of each organic acid (0, 10, 20, and 30 mM), and PSB strain (Bacillus sp.) were applied to aerobic rice. Total bacterial populations, amount of P solubilization, P uptake, soil pH, and root morphology were determined. The results of the study showed significantly high P solubilization in PSB with organic acid treatments. Among the two organic acids, oxalic acid was found more effective compared to malic acid. Application of oxalic acid at 20 mM along with PSB16 significantly increased soluble soil P (28.39 mg kg−1), plant P uptake (0.78 P pot−1), and plant biomass (33.26 mg). Addition of organic acids with PSB and PR had no influence on soil pH during the planting period. A higher bacterial population was found in rhizosphere (8.78 log10 cfu g−1) compared to the nonrhizosphere and endosphere regions. The application of organic acids along with PSB enhanced soluble P in the soil solution, improved root growth, and increased plant biomass of aerobic rice seedlings without affecting soil pH. PMID:24288473

  11. Artificial citrate operon confers mineral phosphate solubilization ability to diverse fluorescent pseudomonads.

    PubMed

    Adhikary, Hemanta; Sanghavi, Paulomi B; Macwan, Silviya R; Archana, Gattupalli; Naresh Kumar, G

    2014-01-01

    Citric acid is a strong acid with good cation chelating ability and can be very efficient in solubilizing mineral phosphates. Only a few phosphate solubilizing bacteria and fungi are known to secrete citric acids. In this work, we incorporated artificial citrate operon containing NADH insensitive citrate synthase (gltA1) and citrate transporter (citC) genes into the genome of six-plant growth promoting P. fluorescens strains viz., PfO-1, Pf5, CHAO1, P109, ATCC13525 and Fp315 using MiniTn7 transposon gene delivery system. Comprehensive biochemical characterization of the genomic integrants and their comparison with plasmid transformants of the same operon in M9 minimal medium reveals the highest amount of ∼7.6±0.41 mM citric and 29.95±2.8 mM gluconic acid secretion along with ∼43.2±3.24 mM intracellular citrate without affecting the growth of these P. fluorescens strains. All genomic integrants showed enhanced citric and gluconic acid secretion on Tris-Cl rock phosphate (TRP) buffered medium, which was sufficient to release 200-1000 µM Pi in TRP medium. This study demonstrates that MPS ability could be achieved in natural fluorescent pseudomonads by incorporation of artificial citrate operon not only as plasmid but also by genomic integration.

  12. Characterization of mineral phosphate solubilization traits from a barley rhizosphere soil functional metagenome.

    PubMed

    Chhabra, Sagar; Brazil, Dina; Morrissey, John; Burke, James I; O'Gara, Fergal; N Dowling, David

    2013-10-01

    Mineral phosphate solubilization (MPS) microorganisms are important for their provision of orthophosphate anions for plant growth promotion activity in soil. In this study, we applied a functional metagenomic approach to identify this trait directly from the microbiome in barley rhizosphere soil that had not received P fertilizer over a 15-year period. A fosmid system was used to clone the metagenome of which 18,000 clones (~666 Mb of DNA) was screened for MPS. Functional assays and High Performance Liquid Chromatography analysis recognized gluconic acid production and MPS activity in the range 24.8-77.1 mmol/L and 27.6-38.16 μg/mL, respectively, when screened in an Escherichia coli host (at frequency of one MPS-positive clone hit per 114 Mb DNA tested). The MPS clones (with average insert size of ~37 kb) were analysed by 454 Roche sequencing and annotated. A number of genes/operons with homology to Phosphorous (P) uptake, regulatory and solubilization mechanisms were identified, linking the MPS function to the uncultivated microbiome present in barley rhizosphere soil.

  13. Microbial recovery of metals from spent coal liquefaction catalysts. Quarterly report, January 1994--March 1994

    SciTech Connect

    Sandbeck, K.A.; Cleveland, D.H.

    1994-07-01

    Mo release from spent coal liquefaction catalysts has been shown to be dependent upon many parameters, but release is dominated by microbial growth. The microbial Mo release is a rapid process requiring less than one week for 90% of the releaseable Mo to be solubilized from whole washed (THF) catalyst. It could be expected that the rates would be even greater with crushed catalyst. Efforts are now centering on optimizing the parameters that stimulate microbial growth and action.

  14. Phosphate solubilization potential and stress tolerance of Eupenicillium parvum from tea soil.

    PubMed

    Vyas, Pratibha; Rahi, Praveen; Chauhan, Anjali; Gulati, Arvind

    2007-08-01

    Eupenicillium parvum was recorded for first time during isolation of phosphate-solubilizing microorganisms from the tea rhizosphere. The fungus developed a phosphate solubilization zone on modified Pikovskaya agar, supplemented with tricalcium phosphate. Quantitative estimation of phosphate solubilization in Pikovskaya broth showed high solubilization of tricalcium phosphate and aluminium phosphate. The fungus also solubilized North Carolina rock phosphate and Mussoorie rock phosphate, and exhibited high levels of tolerance against desiccation, acidity, salinity, aluminium, and iron. Solubilization of inorganic phosphates by the fungus was also observed under high stress levels of aluminium, iron, and desiccation, though the significant decline in phosphate solubilization was marked in the presence of aluminium than iron. The fungal isolate showed 100% identity with E. parvum strain NRRL 2095 ITS 1, 5.8S rRNA gene and ITS 2, complete sequence; and 28S rRNA gene, partial sequence.

  15. Hydrotropic Solubilization of Lipophilic Drugs for Oral Delivery: The Effects of Urea and Nicotinamide on Carbamazepine Solubility–Permeability Interplay

    PubMed Central

    Beig, Avital; Lindley, David; Miller, Jonathan M.; Agbaria, Riad; Dahan, Arik

    2016-01-01

    Hydrotropy refers to increasing the water solubility of otherwise poorly soluble compound by the presence of small organic molecules. While it can certainly increase the apparent solubility of a lipophilic drug, the effect of hydrotropy on the drugs’ permeation through the intestinal membrane has not been studied. The purpose of this work was to investigate the solubility–permeability interplay when using hydrotropic drug solubilization. The concentration-dependent effects of the commonly used hydrotropes urea and nicotinamide, on the solubility and the permeability of the lipophilic antiepileptic drug carbamazepine were studied. Then, the solubility–permeability interplay was mathematically modeled, and was compared to the experimental data. Both hydrotropes allowed significant concentration-dependent carbamazepine solubility increase (up to ∼30-fold). A concomitant permeability decrease was evident both in vitro and in vivo (∼17-fold for nicotinamide and ∼9-fold for urea), revealing a solubility–permeability tradeoff when using hydrotropic drug solubilization. A relatively simplified simulation approach based on proportional opposite correlation between the solubility increase and the permeability decrease at a given hydrotrope concentration allowed excellent prediction of the overall solubility–permeability tradeoff. In conclusion, when using hydrotropic drug solubilization it is prudent to not focus solely on solubility, but to account for the permeability as well; achieving optimal solubility–permeability balance may promote the overall goal of the formulation to maximize oral drug exposure. PMID:27826241

  16. Recovery Act - Large Scale SWNT Purification and Solubilization

    SciTech Connect

    Michael Gemano; Dr. Linda B. McGown

    2010-10-07

    The goal of this Phase I project was to establish a quantitative foundation for development of binary G-gels for large-scale, commercial processing of SWNTs and to develop scientific insight into the underlying mechanisms of solubilization, selectivity and alignment. In order to accomplish this, we performed systematic studies to determine the effects of G-gel composition and experimental conditions that will enable us to achieve our goals that include (1) preparation of ultra-high purity SWNTs from low-quality, commercial SWNT starting materials, (2) separation of MWNTs from SWNTs, (3) bulk, non-destructive solubilization of individual SWNTs in aqueous solution at high concentrations (10-100 mg/mL) without sonication or centrifugation, (4) tunable enrichment of subpopulations of the SWNTs based on metallic vs. semiconductor properties, diameter, or chirality and (5) alignment of individual SWNTs.

  17. Effect of rhamnolipid biosurfactant on solubilization of polycyclic aromatic hydrocarbons.

    PubMed

    Li, Shudong; Pi, Yongrui; Bao, Mutai; Zhang, Cong; Zhao, Dongwei; Li, Yiming; Sun, Peiyan; Lu, Jinren

    2015-12-15

    Rhamnolipid biosurfactant-producing bacteria, Bacillus Lz-2, was isolated from oil polluted water collected from Dongying Shengli oilfield, China. The factors that influence PAH solubilization such as biosurfactant concentration, pH, ionic strength and temperature were discussed. The results showed that the solubilities of naphthalene, phenanthrene and pyrene increased linearly with the rise of rhamnolipid biosurfactant dose above the biosurfactant critical micelle concentration (CMC). Furthermore, the molar solubilization ratio (MSR) values decreased in the following order: naphthalene>phenanthrene>pyrene. However, the solubility percentage increased and followed the opposite order: pyrene>phenanthrene>naphthalene. The solubilities of PAHs in rhamnolipid biosurfactant solution increased with the rise of pH and ionic strength, and reached the maximum values under the conditions of pH11 and NaCl concentration 8 g · L(-1). The solubility of phenanthrene and pyrene increased with the rise of temperature.

  18. Detergent solubilization of the EGF receptor from A431 cells

    NASA Technical Reports Server (NTRS)

    Dayanidhi, R.; Rintoul, D. A.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    Functional reconstitution of purified preparations of human epidermal growth factor receptor (EGFR) requires dissociation of the protein from its plasma membrane lipid environment. Solubilization of membrane proteins in this manner requires the use of detergents, which are known to disrupt plasma membrane lipid/protein interactions. We have investigated the ability of three nonionic detergents to solubilize the human EGFR selectively, and have also analyzed the effect of these various treatments on the intrinsic tyrosyl kinase activity of the receptor. The nonionic detergent known as n-octyl glucoside (n-octyl beta-D-glucopyranoside) was found to give the best combination of selectivity, yield, and maintenance of enzymatic activity of the human EGFR.

  19. The mechanism of detergent solubilization of lipid bilayers.

    PubMed

    Lichtenberg, Dov; Ahyayauch, Hasna; Goñi, Félix M

    2013-07-16

    Multiple data are available on the self-assembly of mixtures of bilayer-forming amphiphiles, particularly phospholipids and micelle-forming amphiphiles, commonly denoted detergents. The structure of such mixed assemblies has been thoroughly investigated, described in phase diagrams, and theoretically rationalized in terms of the balance between the large spontaneous curvature of the curvophilic detergent and the curvophobic phospholipids. In this critical review, we discuss the mechanism of this process and try to explain the actual mechanism involved in solubilization. Interestingly, membrane solubilization by some detergents is relatively slow and the common attribute of these detergents is that their trans-bilayer movement, commonly denoted flip-flop, is very slow. Only detergents that can flip into the inner monolayer cause relatively rapid solubilization of detergent-saturated bilayers. This occurs via the following sequence of events: 1), relatively rapid penetration of detergent monomers into the outer monolayer; 2), trans-membrane equilibration of detergent monomers between the two monolayers; 3), saturation of the bilayer by detergents and consequent permeabilization of the membrane; and 4), transition of the whole bilayer to thread-like mixed micelles. When the detergent cannot flip to the inner monolayer, the outer monolayer becomes unstable due to mass imbalance between the monolayers and inclusion of the curvophilic detergent molecules in a flat surface. Consequently, the outer monolayer forms mixed micellar structures within the outer monolayer. Shedding of these micelles into the aqueous solution results in partial solubilization. The consequent leakage of detergent into the liposome results in trans-membrane equilibration of detergent and subsequent micellization through the rapid bilayer-saturation mechanism.

  20. Fungal attack on rock: solubilization and altered infrared spectra.

    PubMed

    Silverman, M P; Munoz, E F

    1970-09-04

    Penicillium simplicissimum, isolated from weathering basalt, produced citric acid when grown in a glucose-mineral salts medium with basalt, granite, granodiorite, rhyolite, andesite, peridotite, dunite, or quartzite. After 7 days' growth as much as 31 percent of the silicon, 11 percent of the aluminum, 64 percent of the iron, and 59 percent of the magnesium in some of the rocks were solubilized, and a number of rocks showed altered infrared absorption in the silicon-oxygen vibration region.

  1. Phosphate solubilization potential and modeling of stress tolerance of rhizobacteria from rice paddy soil in northern Iran.

    PubMed

    Bakhshandeh, Esmaeil; Rahimian, Heshmatollah; Pirdashti, Hematollah; Nematzadeh, Ghorban Ali

    2014-09-01

    The purposes of this study were to evaluate the phosphate solubilization activity of bacteria isolated from the rhizosphere of rice paddy soil in northern Iran, and to study the effect of temperature, NaCl and pH on the growth of these isolates by modeling. Three of the most effective strains from a total of 300 isolates were identified and a phylogenetic analysis was carried out by 16S rDNA sequencing. The isolates were identified as Pantoea ananatis (M36), Rahnella aquatilis (M100) and Enterobacter sp. (M183). These isolates showed multiple plant growth-promoting attributes such as phosphate solubilization activity and indole-3-acetic acid (IAA) production. The M36, M100 and M183 isolates were able to solubilize 172, 263 and 254 µg ml(-1) of Ca3(PO4)2 after 5 days of growth at 28 °C and pH 7.5, and to produce 8.0, 2.0 and 3.0 μg ml(-1) of IAA when supplemented with L-tryptophan (1 mg ml(-1)) for 72 h, at 28 °C and pH 7.0, respectively. The solubilization of insoluble phosphate was associated with a drop in the pH of the culture medium and there was an inverse relationship between pH and solubilized P (r = -0.98, P < 0.0952). There were no significant differences among isolates in terms of acidity tolerance based on their confidence limits as assessed by segmented model analysis and all isolates were able to grow at pH 4.3-11 (with optimum at 7.0-7.5). Based on a sigmoidal trend of a three-parameter logistic model, the salt concentration required for 50 % inhibition was 8.15, 6.30 and 8.23 % NaCl for M36, M100 and M183 isolates, respectively. Moreover, the minimum and maximum growth temperatures estimated by the segmented model were 5.0 and 42.75 °C for M36, 12.76 and 40.32 °C for M100, and 10.63 and 43.66 °C for M183. The three selected isolates could be deployed as inoculants to promote plant growth in an agricultural environment.

  2. Solubilization of dibutyltin dichloride with surfactant solutions in single and mixed oil systems.

    PubMed

    Damrongsiri, S; Tongcumpou, C; Weschayanwiwat, P; Sabatini, D A

    2010-09-15

    The harmful effects of organometallic compounds and their metabolites on the environment and human health require the development of more effective remediation methods. Surfactant enhanced remediation has been considered as a potential method for the removal of organometallic compounds; however, additional understanding is needed about the solubilization processes of these compounds. The surfactant enhanced solubilization of dibutyltin dichloride (DBT), an organometallic compound, was the focus of this research. In addition, the synergistic effects of DBT solubilization in perchloroethylene (PCE) and decane mixtures were evaluated. The results indicate that PCE and decane were solubilized into the core of these surfactant micelles in both single and mixed oil systems. DBT solubilization was limited when DBT alone was present (single oil system), and the nature of the solubilization isotherm suggests that DBT solubilization tended to occur near the micelle surface in a single oil system. DBT solubilization was found to increase when present in the PCE and decane oil mixture. PCE and decane may have facilitated the solubilization of DBT because they were solubilized in the micelle core. From this study, it may be concluded that the DBT behaves like polar oil such as dodecanol, having properties of a polar organic compound.

  3. Dielectric properties of solutions of oil materials solubilized by sodium dodecyl sulfate in aqueous solutions

    SciTech Connect

    Abe, M.; Shimizu, A.; Ogino, K.

    1982-08-01

    One of the most important properties of micellar systems is their ability to solubilize a variety of species. For aqueous micelles, solubilization is related closely to the hydrophobic and hydrophilic properties of the solubilizate. Different sites of solubilization and orientations may be involved, depending on the structure of the solubilizate. A number of studies on solubilization have been performed experimentally and theoretically. Dielectric constant measurement has proved to be a powerful tool for the investigation of permanent dipole moments of various molecules and of the behavior in solution of various substances, and has been applied in various fields. This technique has been used to determine the chemical structure of surfactants, but not to investigate the solubilization of oily materials in aqueous solution. The dielectric constants and ac electric conductivities observed when a solubilizate is added to an aqueous solution of an anionic surfactant and the differences in the solubilizing behavior due to different kinds of polar groups are discussed. 30 references.

  4. Actions of taurine on the GABA-benzodiazepine receptor complex solubilized from rat brain.

    PubMed

    Malminen, O; Kontro, P

    1987-01-01

    The actions of taurine on the solubilized GABA-benzodiazepine receptor complex were investigated, and the results compared to those obtained with detergent-treated membrane-bound receptors. The receptor complex of adult rat brain was solubilized with Triton X-100 or CHAPS (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulphonate). The properties of the solubilized GABA and flunitrazepam binding sites were similar to those in washed brain membranes. Taurine displaced GABA from its receptor sites and inhibited GABA stimulation of flunitrazepam binding to receptor complexes solubilized with Triton X-100. Thus the modulatory action of taurine on the receptor complex in washed membrane preparations was well preserved after this solubilization. No specific taurine binding to either Triton- or CHAPS-solubilized sample could be demonstrated.

  5. Evaluation of the ultrasonic method for solubilizing Daphnia magna before liquid scintillation counting

    SciTech Connect

    Dauble, D.D.; Hanf, R.W. Jr.; Carlile, D.W.

    1984-11-01

    Adult Daphnia magna were exposed to /sup 14/C-labeled phenol and tissues analyzed for /sup 14/C uptake by three methods: (1) tissue solubilizer, (2) tissue solubilizer plus sonication, and (3) sonication alone. Analysis by liquid scintillation counting revealed that measurements of total activity among treatments were not significantly different (..cap alpha.. less than or equal to 0.10) at two count levels. Sonicated samples showed less variation than tissue samples that were solubilized. 5 references, 1 table.

  6. Biochemical solubilization of toxic salts from residual geothermal brines and waste waters

    DOEpatents

    Premuzic, E.T.; Lin, M.S.

    1994-11-22

    A method of solubilizing metal salts such as metal sulfides in a geothermal sludge using mutant Thiobacilli selected for their ability to metabolize metal salts at high temperature is disclosed. The method includes the introduction of mutated Thiobacillus ferrooxidans and Thiobacillus thiooxidans to a geothermal sludge or brine. The microorganisms catalyze the solubilization of metal salts. For instance, in the case of metal sulfides, the microorganisms catalyze the solubilization to form soluble metal sulfates. 54 figs.

  7. Biochemical solubilization of toxic salts from residual geothermal brines and waste waters

    DOEpatents

    Premuzic, Eugene T.; Lin, Mow S.

    1994-11-22

    A method of solubilizing metal salts such as metal sulfides in a geothermal sludge using mutant Thiobacilli selected for their ability to metabolize metal salts at high temperature is disclosed, The method includes the introduction of mutated Thiobacillus ferrooxidans and Thiobacillus thiooxidans to a geothermal sludge or brine. The microorganisms catalyze the solubilization of metal salts, For instance, in the case of metal sulfides, the microorganisms catalyze the solubilization to form soluble metal sulfates.

  8. Biodegradation kinetics of phenanthrene solubilized in surfactant micelles

    SciTech Connect

    Grimberg, S.J.; Aitken, M.D.

    1995-12-31

    The biodegradation of phenanthrene solubilized in surfactant micelles was studied using a simple, well-defined laboratory system. The system was designed to evaluate whether phenanthrene present in micelles of the nonionic surfactant Tergitol NP-10 was available to a phenanthrene-degrading bacterium. Results indicate that micellized phenanthrene is essentially unavailable to the microorganism, so that only the phenanthrene present in the aqueous phase is degraded. A modified Michaelis-Menten equation was developed to quantify the effects of surfactant concentration on phenanthrene uptake rates. Experimental data were described well with this equation.

  9. Localized Metal Solubilization in the Rhizosphere of Salix smithiana upon Sulfur Application

    PubMed Central

    2015-01-01

    A metal-accumulating willow was grown under greenhouse conditions on a Zn/Cd-polluted soil to investigate the effects of sulfur (S0) application on metal solubility and plant uptake. Soil porewater samples were analyzed 8 times during 61 days of growth, while DGT-measured metal flux and O2 were chemically mapped at selected times. Sulfur oxidation resulted in soil acidification and related mobilization of Mn, Zn, and Cd, more pronounced in the rooted compared to bulk soil. Chemical imaging revealed increased DGT-measured Zn and Cd flux at the root-soil interface. Our findings indicated sustained microbial S0 oxidation and associated metal mobilization close to root surfaces. The localized depletion of O2 along single roots upon S0 addition indicated the contribution of reductive Mn (oxy)hydoxide dissolution with Mn eventually becoming a terminal electron acceptor after depletion of O2 and NO3–. The S0 treatments increased the foliar metal concentrations (mg kg–1 dwt) up to 10-fold for Mn, (5810 ± 593), 3.3-fold for Zn (3850 ± 87.0), and 1.7-fold for Cd (36.9 ± 3.35), but had no significant influence on biomass production. Lower metal solubilization in the bulk soils should translate into reduced leaching, offering opportunities for using S0 as environmentally favorable amendment for phytoextraction of metal-polluted soils. PMID:25782052

  10. An optimized regulating method for composting phosphorus fractions transformation based on biochar addition and phosphate-solubilizing bacteria inoculation.

    PubMed

    Wei, Yuquan; Zhao, Yue; Wang, Huan; Lu, Qian; Cao, Zhenyu; Cui, Hongyang; Zhu, Longji; Wei, Zimin

    2016-12-01

    The study was conducted to investigate the influence of biochar and/or phosphate-solubilizing bacteria (PSB) inoculants on microbial biomass, bacterial community composition and phosphorus (P) fractions during kitchen waste composting amended with rock phosphate (RP). There were distinct differences in the physic-chemical parameters, the proportion of P fractions and bacterial diversity in different treatments. The contribution of available P fractions increased during composting especially in the treatment with the addition of PSB and biochar. Redundancy analysis showed that bacterial compositions were significantly influenced by P content, inoculation and biochar. Variance partitioning further showed that synergy of inoculated PSB and indigenous bacterial communities and the joint effect between biochar and bacteria explained the largest two proportion of the variation in P fractions. Therefore, the combined application of PSB and biochar to improve the inoculation effect and an optimized regulating method were suggested based on the distribution of P fractions.

  11. Solubilization of insoluble inorganic phosphate by Burkholderia cepacia DA23 isolated from cultivated soil

    PubMed Central

    Song, Ok-Ryul; Lee, Seung-Jin; Lee, Yong-Seok; Lee, Sang-Cheol; Kim, Keun-Ki; Choi, Yong-Lark

    2008-01-01

    A mineral phosphate solubilizing bacterium, Burkholderia cepacia DA23 has been isolated from cultivated soils. Phosphate-solubilizing activities of the strain against three types of insoluble phosphate were quantitatively determined. When 3% of glucose concentration was used for carbon source, the strain had a marked mineral phosphate-solubilizing activity. Mineral phosphate solubilization was directly related to the pH drop by the strain. Analysis of the culture medium by high pressure liquid chromatography identified gluconic acid as the main organic acid released by Burkholderia cepacia DA23. Gluconic acid production was apparently the result of the glucose dehydrogenase activity and glucose dehydrogenase was affected by phosphate regulation. PMID:24031195

  12. Complete solubilization of pectins from cotton suspension culture cell walls with retention of most structural features

    SciTech Connect

    Mort, A.J.; Oiu, Feng; Otiko, G.; Maness, N.O.; West, P. ); An, Jinhua Univ. of Georgia, Athens ); Oi, Xiaoyang Univ. of Cincinnati, OH )

    1993-05-01

    Cotton suspension culture cell walls contain four major pectin substructures: (1) rhamnogalacturonan I (RGI), (2) rhamnogalacturonan II, (3) highly methyl esterified homogalacturonan, and (4) homogalacturonan of low degree of methyl esterification. Methods are described to solubilize and isolate each of the four major substructures from the cell walls in high yields. RGII is completely solubilized by an easily purified endopolygalacturonase (EPG). Around 40% of RGI can be solubilized by the sequential action of this EPG and a commercially available cellulase. Almost all of the RGI along with xyloglucan can be solubilized after the EPG treatment using strong alkali. Highly methyl esterified homogalacturonan (degree of methyl esterification [approximately]40%) is solubilized into water after HF treatment of the untreated walls, at [minus]23[degrees], and homogalacturonans with a very low degree of methyl esterification ([approximately]10%) can subsequently be solubilized into 500 mM imidazole buffer. the highly methyl esterified homogalacturonan co-solubilizes with the RGI during several extraction procedures and co-chromatographs with it, indicating that they are covalently attached to each other in the cell walls. Little of the RGI is solubilized from cotton walls by EPG digestion without a subsequent treatment that co-solubilizes the xyloglucan or degrades the xyloglucan, indicating crosslinks exist between the RGI and much of the xyloglucan.

  13. Solubilization of high affinity corticotropin-releasing factor receptors from rat brain: Characterization of an active digitonin-solubilized receptor complex

    SciTech Connect

    Grigoriadis, D.E.; Zaczek, R.; Pearsall, D.M.; De Souza, E.B. )

    1989-12-01

    The binding characteristics of CRF receptors in rat frontal cerebral cortex membranes solubilized in 1% digitonin were determined. The binding of (125I)Tyro-ovine CRF ((125I)oCRF) to solubilized membrane proteins was dependent on incubation time, temperature, and protein concentration, was saturable and of high affinity, and was absent in boiled tissue. The solubilized receptors retained their high affinity for (125I) oCRF in the solubilized state, exhibiting a dissociation constant (KD) of approximately 200 pM, as determined by direct binding saturation isotherms. Solubilized CRF receptors maintained the rank order of potencies for various related and unrelated CRF peptides characteristic of the membrane CRF receptor: rat/human CRF congruent to ovine CRF congruent to Nle21,38-rat CRF greater than alpha-helical oCRF-(9-41) greater than oCRF-(7-41) much greater than vasoactive intestinal peptide, arginine vasopressin, or the substance-P antagonist. Furthermore, the absolute potencies (Ki values) for the various CRF-related peptides in solubilized receptors were almost identical to those observed in the membrane preparations, indicating that the CRF receptor retained its high affinity binding capacity in the digitonin-solubilized state. Chemical affinity cross-linking of digitonin-solubilized rat cortical membrane proteins revealed a specifically labeled protein with an apparent mol wt of 58,000 which was similar to the labeled protein in native membrane homogenates. Although solubilized CRF receptors retained their high affinity for agonists, their sensitivity for guanine nucleotide was lost. Size exclusion chromatography substantiated these results, demonstrating that in the presence or absence of guanine nucleotides, (125I)oCRF labeled the same size receptor complex.

  14. Solubilization and electrophoretic characterization of select edible nut seed proteins.

    PubMed

    Sathe, Shridhar K; Venkatachalam, Mahesh; Sharma, Girdhari M; Kshirsagar, Harshal H; Teuber, Suzanne S; Roux, Kenneth H

    2009-09-09

    The solubility of almond, Brazil nut, cashew nut, hazelnut, macadamia, pecan, pine nut, pistachio, walnut, and peanut proteins in several aqueous solvents was qualitatively and quantitatively assessed. In addition, the effects of extraction time and ionic strength on protein solubility were also investigated. Electrophoresis and protein determination (Lowry, Bradford, and micro-Kjeldahl) methods were used for qualitative and quantitative assessment of proteins, respectively. Depending on the seed, buffer type and ionic strength significantly affected protein solubility. The results suggest that buffered sodium borate (BSB; 0.1 M H(3)BO(3), 0.025 M Na(2)B(4)O(7), 0.075 M NaCl, pH 8.45) optimally solubilizes nut seed proteins. Qualitative differences in seed protein electrophoretic profiles were revealed. For a specific seed type, these differences were dependent on the solvent(s) used to solubilize the seed proteins. SDS-PAGE results suggest the polypeptide molecular mass range for the tree nut seed proteins to be 3-100 kDa. The results of native IEF suggested that the proteins were mainly acidic, with a pI range from >4.5 to <7.0. Western immunoblotting experiments indicated that rabbit polyclonal antibodies recognized substantially the same polypeptides as those recognized by the corresponding pooled patient sera IgE.

  15. Ozone solubilizes elastin and increases its susceptibility to elastase

    SciTech Connect

    Winters, R.S.; Johnson, D.A. )

    1991-03-11

    Ozone is a powerful oxidant gas that may contribute to lung diseases such as emphysema. Because the hallmark of emphysema is destruction of the elastin rich alveoli of the lung, ozonization of elastin was studied in vitro to examine the effects of ozone on elastin structure and susceptibility to proteolysis. Samples of bovine ligamentum nuchae elastin were suspended in 15 ml PBS and bubbled with 13.7 ppm ozone in argon at a flow rate of 3.5 ml/min. Ozone treatment resulted in the solubilization of elastin as evidenced by a visual decrease in turbidity and an increase in the 225 nm absorbance of the supernatant fraction after centrifugation to pellet the insoluble elastin. Insoluble elastin recovered from exposed suspensions was examined for proteolytic susceptibility with human neutrophil elastase (HNE), by incubating 600 {mu}g samples in 1 ml of 50 mM Tris-HCl, 200 mM NaCl, pH 8.0 with 3 {mu}g HNE for various times at room temp. Elastin proteolysis was followed by measuring the 225 nm absorbance of solubilized peptides in supernatant fractions. Ozone exposed elastin, which had been previously ozonized to 5% solubility was found to be approximately twice as susceptible to proteolysis as native elastin.

  16. Transfer Specificity of Detergent-Solubilized Fenugreek Galactomannan Galactosyltransferase

    PubMed Central

    Edwards, Mary E.; Marshall, Elaine; Gidley, Michael J.; Reid, J.S. Grant

    2002-01-01

    The current experimental model for galactomannan biosynthesis in membrane-bound enzyme systems from developing legume-seed endosperms involves functional interaction between a GDP-mannose (Man) mannan synthase and a UDP-galactose (Gal) galactosyltransferase. The transfer specificity of the galactosyltransferase to the elongating mannan chain is critical in regulating the distribution and the degree of Gal substitution of the mannan backbone of the primary biosynthetic product. Detergent solubilization of the galactosyltransferase of fenugreek (Trigonella foenum-graecum) with retention of activity permitted the partial purification of the enzyme and the cloning and sequencing of the corresponding cDNA with proof of functional identity. We now document the positional specificity of transfer of (14C)Gal from UDP-(14C)Gal to manno-oligosaccharide acceptors, chain lengths 5 to 8, catalyzed by the detergent-solubilized galactosyltransferase. Enzymatic fragmentation analyses of the labeled products showed that a single Gal residue was transferred per acceptor molecule, that the linkage was (1→6)-α, and that there was transfer to alternative Man residues within the acceptor molecules. Analysis of the relative frequencies of transfer to alternative Man residues within acceptor oligosaccharides of different chain length allowed the deduction of the substrate subsite recognition requirement of the galactosyltransferase. The enzyme has a principal recognition sequence of six Man residues, with transfer of Gal to the third Man residue from the nonreducing end of the sequence. These observations are incorporated into a refined model for enzyme interaction in galactomannan biosynthesis. PMID:12114592

  17. Improving the aqueous solubility of triclosan by solubilization, complexation, and in situ salt formation.

    PubMed

    Grove, Christine; Liebenberg, Wilna; du Preez, Jan L; Yang, Wenzhan; de Villiers, Melgardt M

    2003-01-01

    Triclosan, an antimicrobial, although widely incorporated into many skin care products, toothpastes, and liquid soaps, presents formulation difficulties because it is practically insoluble in water. The objective of this study was to improve the aqueous solubility of triclosan through solubilization, complexation, and salt formation. The solubility of triclosan in distilled water and in phosphate buffers (pH 7.4) was determined at 30 degrees C. The order of solubilizing performance of the solubilizers was: N-methylglucamine> or =L-arginine>sodium lauryl sulfate>beta-cyclodextrin> or =hydroxypropyl-beta-cyclodextrin>ethanolamine>sodium benzoate>sodium methyl 4-hydroxybenzoate>triethanolamine> or =diethanolamine. These solubilizers increased the solubility of triclosan from 80- to 6000-fold. Micellar solubilization and the formation of either salts or complexes are postulated as possible mechanisms for the increase in the solubility of triclosan by the surfactant sodium lauryl sulphate, the cyclic sugar derivatives beta-cyclodextrin and 2-hydropropyl-beta-cyclodextrin, the amino acid L-arginine, and the amino sugar alcohol N-methylglucamine. Furthermore, although the bacteriostatic efficacy of triclosan was significantly increased when solubilized with N-methylglucamine, L-arginine, and ethanolamine, increased solubilization did not increase the effectiveness of triclosan for all solubilizers tested.

  18. Carbon and Nitrogen Sources Influence Tricalcium Phosphate Solubilization and Extracellular Phosphatase Activity by Talaromyces flavus.

    PubMed

    Stefanoni Rubio, P J; Godoy, M S; Della Mónica, I F; Pettinari, M J; Godeas, A M; Scervino, J M

    2016-01-01

    The aim of this work was to study phosphate (P) solubilization (and the processes involved in this event) by Talaromyces flavus (BAFC 3125) as a function of carbon and/or nitrogen sources. P solubilization was evaluated in NBRIP media supplemented with different carbon (glucose, sorbitol, sucrose, and fructose) and nitrogen (L-asparagine, urea, ammonium sulfate (AS), and ammonium nitrate (AN) combinations. The highest P solubilization was related to the highest organic acid production (especially gluconic acid) and pH drop for those treatments where glucose was present. Also P solubilization was higher when an inorganic nitrogen source was supplemented to the media when compared to an organic one. Although not being present an organic P source, phosphatase activity was observed. This shows that P mineralization and P solubilization can occur simultaneously, and that P mineralization is not induced by the enzyme substrate. The combination that showed highest P solubilization was for AN-glucose. The highest acid phosphatase activity was for AS-fructose, while for alkaline phosphatase were for AS-fructose and AN-fructose. Acid phosphatase activity was higher than alkaline. P solubilization and phosphatase activity (acid and alkaline) were influenced by the different carbon-nitrogen combinations. A better understanding of phosphate-solubilizing fungi could bring a better use of soil P.

  19. Direct solubilization of enzyme aggregates with enhanced activity in nonaqueous media.

    PubMed

    Akbar, Umar; Aschenbrenner, Carl D; Harper, Michael R; Johnson, Harvey R; Dordick, Jonathan S; Clark, Douglas S

    2007-04-15

    A protein solubilization method has been developed to directly solubilize protein clusters into organic solvents containing small quantities of surfactant and trace amounts of water. Termed "direct solubilization," this technique was shown to solubilize three distinct proteins - subtilisin Carlsberg, lipase B from Candida antarctica, and soybean peroxidase - with much greater efficiencies than extraction of the protein from aqueous solution into surfactant-containing organic solvents (referred to as extraction). More significant, however, was the dramatic increase in directly solubilized enzyme activity relative to extracted enzyme activity, particularly for subtilisin and lipase in polar organic solvents. For example, in THF the initial rate towards bergenin transesterification was ca. 70 times higher for directly solubilized subtilisin than for the extracted enzyme. Furthermore, unlike their extracted counterparts, the directly solubilized enzymes yielded high product conversions across a spectrum of non-polar and polar solvents. Structural characterization of the solubilized enzymes via light scattering and atomic force microscopy revealed soluble proteins consisting of active enzyme aggregates containing approximately 60 and 100 protein molecules, respectively, for subtilisin and lipase. Formation of such clusters appears to provide a microenvironment conducive to catalysis and, in polar organic solvents at least, may protect the enzyme from solvent-induced inactivation.

  20. Cocrystal Transition Points: Role of Cocrystal Solubility, Drug Solubility, and Solubilizing Agents.

    PubMed

    Lipert, Maya P; Rodríguez-Hornedo, Naír

    2015-10-05

    In this manuscript we bring together concepts that are relevant to the solubilization and thermodynamic stability of cocrystals in the presence of drug solubilizing agents. Simple equations are derived that allow calculation of cocrystal solubilization and transition point solubility. Analysis of 10 cocrystals in 6 different solubilizing agents shows that cocrystal solubilization is quantitatively predicted from drug solubilization. Drug solubilizing agents such as surfactants and lipid-based media are also shown to induce cocrystal transition points, where drug and cocrystal solubilities are equal, and above which the cocrystal solubility advantage over drug is eliminated. We have discovered that cocrystal solubility at the transition point (S*) is independent of solubilizing agent, and can be predicted from knowledge of only the aqueous solubilities of drug and cocrystal. For 1:1 cocrystals, S* = (Scocrystal,aq)(2)/Sdrug,aq. S* is a key indicator of cocrystal thermodynamic stability and establishes the upper solubility limit below which cocrystal is more soluble than the constituent drug. These findings have important implications to tailor cocrystal solubility and stability in pharmaceutical formulations from commonly available drug solubility descriptors.

  1. Effect of an organophosphate pesticide, monocrotophos, on phosphate-solubilizing efficiency of soil fungal isolates.

    PubMed

    Jain, Rachna; Garg, Veena; Saxena, Jyoti

    2015-01-01

    Soil is a sink of pesticide residues as well as microorganisms. Fungi are well known for solubilization of inorganic phosphates, and this activity of fungal isolates may be affected by the presence of pesticide residues in the soil. In the present study, five generically different fungal isolates, viz. Aspergillus niger JQ660373, Aspergillus flavus, Penicillium aculeatum JQ660374, Fusarium pallidoroseum and Macrophomina sp., were tested and compared for their phosphate-solubilizing ability in the absence and presence of monocrotophos (500 mg L(-1)). After 168 h of incubation, four times high amount of tricalcium phosphate was solubilized by isolates in the growth medium containing monocrotophos in comparison to control (without monocrotophos). Concurrently, 78 % of the applied monocrotophos was degraded by these fungal isolates. Kinetics of phosphate solubilization shifted from logarithmic to power model in the presence of monocrotophos. Similarly, the phosphatase activity was also found significantly high in the presence of monocrotophos. The combined order of phosphate solubilization as well as monocrotophos degradation was found to be A. niger JQ660373 > P. aculeatum JQ660374 > A. flavus > F. pallidoroseum > Macrophomina sp. On the contrary, phosphate solubilization negatively correlated with the pH of the growth medium. Hence, it could be concluded that these fungal species efficiently solubilize inorganic phosphates and monocrotophos poses a positive effect on their ability and in turn degraded by them. To the best of our knowledge, this is the first report on P solubilization by Macrophomina sp. and F. pallidoroseum.

  2. Iron(III) reduction and phosphorous solubilization in humid tropical forest soils

    NASA Astrophysics Data System (ADS)

    Peretyazhko, Tanya; Sposito, Garrison

    2005-07-01

    gases (CO 2, H 2 and CH 4). The same positive correlation was found between soluble P release and soluble Fe(II) production throughout incubation, implying that reduction of Fe(III) solubilized P. The Fe(II) produced was mainly particulate, evidently due to the formation of Fe(II) solid phases. Thermodynamic calculations indicated that precipitation of siderite and, in the presence of AQDS, vivianite was favored under the anoxic conditions that developed rapidly in the soil suspensions. Inorganic soluble P released during incubation was very small, indicating that the soluble P produced was mainly in organic form, which is consistent with the hypothesis that P accumulates in soil humus. Our net CO 2 production, H 2 consumption, and Fe(II) production data all suggested that reductive dissolution of Fe(III) (hydr)oxides was a terminal electron-accepting process coupled both to H 2 consumption and organic C oxidation by the native population of microorganisms in the soil. Addition of AQDS accelerated the production of Fe(II) and the release of soluble P, while hastening the decline in H 2 gas levels and suppressing CH 4 production. However, throughout incubation, the same quantitative relationships between soluble Fe(II) and P, and between pE and pH, were found, irrespective of AQDS addition. Thus we conclude that, in our soil incubation experiments, added AQDS functioned with the native microbial population solely as an electron shuttle catalyzing Fe(III) reduction. Whether humic substances in the soil also can act as electron shuttles in this way is a matter for future investigation.

  3. Visualization of surfactant enhanced NAPL mobilization and solubilization in a two-dimensional micromodel

    SciTech Connect

    ZHONG,LIRONG; MAYER,ALEX; GLASS JR.,ROBERT J.

    2000-03-08

    Surfactant-enhanced aquifer remediation is an emerging technology for aquifers contaminated with nonaqueous phase liquids (NAPLs). A two-dimensional micromodel and image capture system were applied to observe NAPL mobilization and solubilization phenomena. In each experiment, a common residual NAPL field was established, followed by a series of mobilization and solubilization experiments. Mobilization floods included pure water floods with variable flow rates and surfactant floods with variations in surfactant formulations. At relatively low capillary numbers (N{sub ca}<10{sup {minus}3}), the surfactant mobilization floods resulted in higher NAPL saturations than for the pure water flood, for similar N{sub ca}.These differences in macroscopic saturations are explained by differences in micro-scale mobilization processes. Solubilization of the residual NAPL remaining after the mobilization stage was dominated by the formation of dissolution fingers, which produced nonequilibrium NAPL solubilization. A macroemulsion phase also as observed to form spontaneously and persist during the solubilization stage of the experiments.

  4. Strategy for large scale solubilization of coal - characterization of Neurospora protein and gene

    SciTech Connect

    Patel, A.; Chen, Y.P.; Mishra, N.C.

    1995-12-31

    Low grade coal placed on mycelial mat of Neurospora crassa growing on Petri plate was found to be solubilized by this fungus. A heat stable protein has been purified to near homogeneity which can solubilize low grade coal in in vitro. The biochemical properties of the Neurospora protein will be presented. The nature of the product obtained after solubilization of coal by Neurospora protein in vivo and in vitro will also be presented. The N-terminus sequence of the amino acids of this protein will be used to design primer for possible cloning of gene for Neurospora protein capable of solubilization of coal in order to develop methodology for coal solubilization on a large scale.

  5. Isolation of Plant Photosystem II Complexes by Fractional Solubilization

    PubMed Central

    Haniewicz, Patrycja; Floris, Davide; Farci, Domenica; Kirkpatrick, Joanna; Loi, Maria C.; Büchel, Claudia; Bochtler, Matthias; Piano, Dario

    2015-01-01

    Photosystem II (PSII) occurs in different forms and supercomplexes in thylakoid membranes. Using a transplastomic strain of Nicotiana tabacum histidine tagged on the subunit PsbE, we have previously shown that a mild extraction protocol with β-dodecylmaltoside enriches PSII characteristic of lamellae and grana margins. Here, we characterize residual granal PSII that is not extracted by this first solubilization step. Using affinity purification, we demonstrate that this PSII fraction consists of PSII-LHCII mega- and supercomplexes, PSII dimers, and PSII monomers, which were separated by gel filtration and functionally characterized. Our findings represent an alternative demonstration of different PSII populations in thylakoid membranes, and they make it possible to prepare PSII-LHCII supercomplexes in high yield. PMID:26697050

  6. Solubilization of poorly water-soluble drugs using solid dispersions.

    PubMed

    Tran, Thao T-D; Tran, Phuong H-L; Khanh, Tran N; Van, Toi V; Lee, Beom-Jin

    2013-08-01

    Many new drugs have been discovered in pharmaceutical industry and exposed their surprised potential therapeutic effects. Unfortunately, these drugs possess low absorption and bioavailability since their solubility limitation in water. Solid dispersion (SD) is the current technique gaining so many attractions from scientists due to its effect on improving solubility and dissolution rate of poorly water-soluble drugs. A number of patents including the most recent inventions have been undertaken in this review to address various respects of this strategy in solubilization of poorly watersoluble drugs including type of carriers, preparation methods and view of technologies used to detect SD properties and mechanisms with the aim to accomplish a SD not only effective on enhanced bioavailability but also overcome difficulties associated with stability and production. Future prospects are as well discussed with an only hope that many developments and researches in this field will be successfully reached and contributed to commercial use for treatment as much as possible.

  7. Enhanced solubilization of curcumin in mixed surfactant vesicles.

    PubMed

    Kumar, Arun; Kaur, Gurpreet; Kansal, S K; Chaudhary, Ganga Ram; Mehta, S K

    2016-05-15

    Self-assemblies of equimolar double and single chain mixed ionic surfactants, with increasing numbers of carbon atoms of double chain surfactant, were analyzed on the basis of fluorescence and conductivity results. Attempts were also made to enhance the solubilization of curcumin in aqueous equimolar mixed surfactant systems. Mixed surfactant assembly was successful in retarding the degradation of curcumin in alkaline media (only 25-28 40% degraded in 10h at pH 13). Fluorescence spectroscopy and fluorescence quenching methods were employed to predict the binding position and mechanism of curcumin with self-assemblies. Results indicate that the interactions take place according to both dynamic and static quenching mechanisms and curcumin was distributed in a palisade layer of mixed aggregates. Antioxidant activity (using DPPH radical) and biocompatibility (using calf-thymus DNA) of curcumin-loaded mixed surfactant formulations were also evaluated. The prepared systems improved the stability, solubility and antioxidant activity of curcumin and additionally are biocompatible.

  8. Marine actinobacteria showing phosphate-solubilizing efficiency in Chorao Island, Goa, India.

    PubMed

    Dastager, Syed G; Damare, Samir

    2013-05-01

    The occurrence and distribution of an actinobacteria group of bacteria capable of dissolving insoluble phosphates were investigated in this study in marine environments, especially in sediments of Chorao Island, Goa Province, India. A total of 200 bacterial isolates of actinobacteria was isolated. All isolates were screened for phosphate-solubilizing activity on Pikovskaya's agar. Thirteen different isolates exhibiting maximum formation of halos (zone of solubilization) around the bacterial colonies were selected for quantitative estimations of P-solubilization. Quantitative estimations for P-solubilization were analyzed for up to 10 days at intervals of 24 h. Maximum solubilization from 89.3 ± 3.1 to 164.1 ± 4.1 μg ml(-1) was observed after 6 days of incubation in six of all isolates, while the isolate NII-1020 showed maximum P-solubilization. The increase in solubilization coincided with the drop in pH. Many of these species showed wide range of tolerance to temperature, pH, and salt concentrations. Further, 16S rRNA gene sequence analyses were carried to identify the bacterial groups which are actively solubilized phosphate in vitro. Gene sequencing results reveal that all isolates were clustered into six different actinobacterial genera: Streptomyces, Microbacterium, Angustibacter, Kocuria, Isoptericola, and Agromyces. The presence of phosphate-solubilizing microorganisms and their ability to solubilize phosphate were indicative of the important role played by bacteria in the biogeochemical cycle of phosphorus and the plant growth in coastal ecosystems.

  9. An In vitro Study of Bio-Control and Plant Growth Promotion Potential of Salicaceae Endophytes.

    PubMed

    Kandel, Shyam L; Firrincieli, Andrea; Joubert, Pierre M; Okubara, Patricia A; Leston, Natalie D; McGeorge, Kendra M; Mugnozza, Giuseppe S; Harfouche, Antoine; Kim, Soo-Hyung; Doty, Sharon L

    2017-01-01

    Microbial communities in the endosphere of Salicaceae plants, poplar (Populus trichocarpa) and willow (Salix sitchensis), have been demonstrated to be important for plant growth promotion, protection from biotic and abiotic stresses, and degradation of toxic compounds. Our study aimed to investigate bio-control activities of Salicaceae endophytes against various soil borne plant pathogens including Rhizoctonia solani AG-8, Fusarium culmorum, Gaeumannomyces graminis var. tritici, and Pythium ultimum. Additionally, different plant growth promoting traits such as biological nitrogen fixation (BNF), indole-3-acetic acid (IAA) biosynthesis, phosphate solubilization, and siderophore production were assessed in all bio-control positive strains. Burkholderia, Rahnella, Pseudomonas, and Curtobacterium were major endophyte genera that showed bio-control activities in the in-vitro assays. The bio-control activities of Burkholderia strains were stronger across all tested plant pathogens as compared to other stains. Genomes of sequenced Burkholderia strains WP40 and WP42 were surveyed to identify the putative genes involved in the bio-control activities. The ocf and hcnABC gene clusters responsible for biosynthesis of the anti-fungal metabolites, occidiofungin and hydrogen cyanide, are present in the genomes of WP40 and WP42. Nearly all endophyte strains showing the bio-control activities produced IAA, solubilized tricalcium phosphate, and synthesized siderophores in the culture medium. Moreover, some strains reduced acetylene into ethylene in the acetylene reduction assay, a common assay used for BNF. Salicaceae endophytes could be useful for bio-control of various plant pathogens, and plant growth promotion possibly through the mechanisms of BNF, IAA production, and nutrient acquisition.

  10. Isolation and characterization of plant growth promoting traits of a rhizobacteria: Pantoea agglomerans lma2.

    PubMed

    Silini-Chérif, H; Silini, A; Ghoul, M; Yadav, S

    2012-03-15

    The use of microbial technology in agriculture is expanding quickly with the identification of new bacterial strains which are more effective in promoting the growth of plants. The rhizobacteria that promote the growth of plants can have a positive effect on the productivity of crops especially when subjected to salt stress. A nitrogen-fixing bacterium was isolated from the wheat rhizosphere of an arid region. The strain was identified on the basis of tests API20E and 16S rRNA sequencing, as Pantoea agglomerans lma2. This strain degraded several carbon sources: sugars (fructose, ribose, dextrin, salicin...), lipids (lecithin, tributyrin and tween 80), proteins (gelatin, casein), grew on KCN and could grow from pH 4 to 8 and had an optimum at pH 7. The growth temperature showed a maximum at 30 degrees C and the bacteria could tolerate from 4 to 41 degrees C and the growth rate was higher when the NaCl concentration was between 100 and 300 mM. The performance of activities enhancing the growth of plants of P. agglomerans lma2 was significantly better in the presence of salt. Rates of Indole Acetic Acid (IAA), siderophores production and solubilization of phosphate increased between 100 and 400 mM NaCl compared to the control without salt. The maximum values were saved to 300 mM for the production of siderophores (18.32%) and solubilization of phosphate (1061.49 microg mL(-1)) and 100 mM for the production of IAA (161 microg mL(-1)). A significant correlation existed between these three activities. These results showed that P. agglomerans lma2 with its Plant Growth Promoting Rhizobacteria (PGPR) and halophilic properties could constitute a good fertilizer in arid and saline zone.

  11. An In vitro Study of Bio-Control and Plant Growth Promotion Potential of Salicaceae Endophytes

    PubMed Central

    Kandel, Shyam L.; Firrincieli, Andrea; Joubert, Pierre M.; Okubara, Patricia A.; Leston, Natalie D.; McGeorge, Kendra M.; Mugnozza, Giuseppe S.; Harfouche, Antoine; Kim, Soo-Hyung; Doty, Sharon L.

    2017-01-01

    Microbial communities in the endosphere of Salicaceae plants, poplar (Populus trichocarpa) and willow (Salix sitchensis), have been demonstrated to be important for plant growth promotion, protection from biotic and abiotic stresses, and degradation of toxic compounds. Our study aimed to investigate bio-control activities of Salicaceae endophytes against various soil borne plant pathogens including Rhizoctonia solani AG-8, Fusarium culmorum, Gaeumannomyces graminis var. tritici, and Pythium ultimum. Additionally, different plant growth promoting traits such as biological nitrogen fixation (BNF), indole-3-acetic acid (IAA) biosynthesis, phosphate solubilization, and siderophore production were assessed in all bio-control positive strains. Burkholderia, Rahnella, Pseudomonas, and Curtobacterium were major endophyte genera that showed bio-control activities in the in-vitro assays. The bio-control activities of Burkholderia strains were stronger across all tested plant pathogens as compared to other stains. Genomes of sequenced Burkholderia strains WP40 and WP42 were surveyed to identify the putative genes involved in the bio-control activities. The ocf and hcnABC gene clusters responsible for biosynthesis of the anti-fungal metabolites, occidiofungin and hydrogen cyanide, are present in the genomes of WP40 and WP42. Nearly all endophyte strains showing the bio-control activities produced IAA, solubilized tricalcium phosphate, and synthesized siderophores in the culture medium. Moreover, some strains reduced acetylene into ethylene in the acetylene reduction assay, a common assay used for BNF. Salicaceae endophytes could be useful for bio-control of various plant pathogens, and plant growth promotion possibly through the mechanisms of BNF, IAA production, and nutrient acquisition. PMID:28348550

  12. Geochemical hosts of solubilized radionuclides in uranium mill tailings

    USGS Publications Warehouse

    Landa, E.R.; Bush, C.A.

    1990-01-01

    The solubilization and subsequent resorption of radionuclides by ore components or by reaction products during the milling of uranium ores may have both economic and environmental consequences. Particle-size redistribution of radium during milling has been demonstrated by previous investigators; however, the identification of sorbing components in the tailings has received little experimental attention. In this study, uranium-bearing sandstone ore was milled, on a laboratory scale, with sulfuric acid. At regular intervals, filtrate from this suspension was placed in contact with mixtures of quartz sand and various potential sorbents which occur as gangue in uranium ores; the potential sorbents included clay minerals, iron and aluminum oxides, feldspar, fluorspar, barite, jarosite, coal, and volcanic glass. After equilibration, the quartz sand-sorbent mixtures were separated from the filtrate and radioassayed by gamma-spectrometry to determine the quantities of 238U, 230Th, 226Ra, and 210Pb sorbed, and the radon emanation coefficients. Sorption of 238U was low in all cases, with maximal sorptions of 1-2% by the bentonite- and coal-bearing samples. 230Th sorption also was generally less than 1%; maximal sorption here was observed in the fluorspar-bearing sample and appears to be associated with the formation of gypsum during milling. 226Ra and 210 Pb generally showed higher sorption than the other nuclides - more than 60% of the 26Ra solubilized from the ore was sorbed on the barite-bearing sample. The mechanism (s) for this sorption by a wide variety of substrates is not yet understood. Radon emanation coefficients of the samples ranged from about 5 to 30%, with the coal-bearing samples clearly demonstrating an emanating power higher than any of the other materials. ?? 1990.

  13. Excellent N-fixing and P-solubilizing traits in earthworm gut-isolated bacteria: A vermicompost based assessment with vegetable market waste and rice straw feed mixtures.

    PubMed

    Hussain, Nazneen; Singh, Archana; Saha, Sougata; Venkata Satish Kumar, Mattaparthi; Bhattacharyya, Pradip; Bhattacharya, Satya Sundar

    2016-12-01

    Vermicomposting is a dependable waste recycling technology which greatly augments N and P levels mainly through microbial action. This paper aims to identify efficient N-fixing (NFB) and P-solubilizing (PSB) bacteria from earthworm intestines. Various combinations of vegetable market waste, rice straw, and cowdung were fed to two earthworm species (Eisenia fetida and Perionyx excavatus). Total organic C decreased, pH shifted towards neutrality, and NPK availability, and microbial (NFB, PSB, and total bacteria) population increased remarkably during vermicomposting with E. fetida. Therefore, 45 NFB and 34 PSB strains isolated from Eisenia gut were initially screened, their inter-dominance assessed, and 8 prolific strains were identified through 16SrRNA sequencing. Interestingly, two novel N-fixing strains of Kluyvera ascorbata emerged as an efficient biofertilizer candidate. Moreover, both N-fixing and P-solubilizing strains of Serratia and Bacillus were isolated from earthworm gut. All the isolated strains significantly improved soil health and facilitated crop growth as compared to commercial biofertilizers.

  14. Synergistic effect of beneficial rhizosphere microflora in biocontrol and plant growth promotion.

    PubMed

    Kannan, Vijayaragahavan; Sureendar, Raman

    2009-04-01

    Biological systems are getting more relevance than chemical control of plant pathogens as they are not only eco-friendly and economic in approach but are also involved in improving the soil consistency and maintenance of natural soil flora. Plant growth promoting rhizosphere microorganisms were isolated from three different tree rhizospheres using selective culture media. Five microorganisms were selected from each rhizosphere soil based on their efficiency and screened for their ability to promote plant growth as a consortium. Each of the developed consortium has a phosphate solubilizer, nitrogen fixer, growth hormone producer, heterotrophic member and an antagonist. The plant growth promoting ability of the microbial members present in the consortium was observed by estimating the IAA production level and also by the nitrogenase activity of the nitrogen fixers. The biocontrol potentiality of the consortium and the antagonist present in the consortium were checked by both dual plate assay and cross-streaking technique. Consortial treatments effected very good growth promotion in Lycopersicon esculentum Mill and the treated plants also developed resistance against wilt pathogen, Fusarium oxysporum f. sp. lycopersici though the effect was well pronounced with consortium developed from Santalum album.

  15. Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence.

    PubMed

    Wang, Ping; Liu, Yalong; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Joseph, Stephen; Pan, Genxing

    2015-10-27

    Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist.

  16. Long-term rice cultivation stabilizes soil organic carbon and promotes soil microbial activity in a salt marsh derived soil chronosequence

    PubMed Central

    Wang, Ping; Liu, Yalong; Li, Lianqing; Cheng, Kun; Zheng, Jufeng; Zhang, Xuhui; Zheng, Jinwei; Joseph, Stephen; Pan, Genxing

    2015-01-01

    Soil organic carbon (SOC) sequestration with enhanced stable carbon storage has been widely accepted as a very important ecosystem property. Yet, the link between carbon stability and bio-activity for ecosystem functioning with OC accumulation in field soils has not been characterized. We assessed the changes in microbial activity versus carbon stability along a paddy soil chronosequence shifting from salt marsh in East China. We used mean weight diameter, normalized enzyme activity (NEA) and carbon gain from straw amendment for addressing soil aggregation, microbial biochemical activity and potential C sequestration, respectively. In addition, a response ratio was employed to infer the changes in all analyzed parameters with prolonged rice cultivation. While stable carbon pools varied with total SOC accumulation, soil respiration and both bacterial and fungal diversity were relatively constant in the rice soils. Bacterial abundance and NEA were positively but highly correlated to total SOC accumulation, indicating an enhanced bio-activity with carbon stabilization. This could be linked to an enhancement of particulate organic carbon pool due to physical protection with enhanced soil aggregation in the rice soils under long-term rice cultivation. However, the mechanism underpinning these changes should be explored in future studies in rice soils where dynamic redox conditions exist. PMID:26503629

  17. Effects of L-arginine on solubilization and purification of plant membrane proteins.

    PubMed

    Arakawa, Junji; Uegaki, Masamichi; Ishimizu, Takeshi

    2011-11-01

    Biochemical analysis of membrane proteins is problematic at the level of solubilization and/or purification because of their hydrophobic nature. Here, we developed methods for efficient solubilization and purification of membrane proteins using L-arginine. The addition of 100 mM of basic amino acids (L-arginine, L-lysine, and L-ornithine) to a detergent-containing solubilization buffer enhanced solubilization (by 2.6-4.3 fold) of a model membrane protein-polygalacturonic acid synthase. Of all the amino acids, arginine was the most effective additive for solubilization of this membrane protein. Arginine addition also resulted in the best solubilization of other plant membrane proteins. Next, we examined the effects of arginine on purification of a model membrane protein. In anion-exchange chromatography, the addition of arginine to the loading and elution buffers resulted in a greater recovery of a membrane protein. In ultrafiltration, the addition of arginine to a protein solution significantly improved the recovery of a membrane protein. These results were thought to be due to the properties of arginine that prevent aggregation of hydrophobic proteins. Taken together, the results of our study showed that arginine is useful for solubilization and purification of aggregate-prone membrane proteins.

  18. Solubilization of lipids and lipid phases by the styrene-maleic acid copolymer.

    PubMed

    Dominguez Pardo, Juan J; Dörr, Jonas M; Iyer, Aditya; Cox, Ruud C; Scheidelaar, Stefan; Koorengevel, Martijn C; Subramaniam, Vinod; Killian, J Antoinette

    2017-01-01

    A promising tool in membrane research is the use of the styrene-maleic acid (SMA) copolymer to solubilize membranes in the form of nanodiscs. Since membranes are heterogeneous in composition, it is important to know whether SMA thereby has a preference for solubilization of either specific types of lipids or specific bilayer phases. Here, we investigated this by performing partial solubilization of model membranes and analyzing the lipid composition of the solubilized fraction. We found that SMA displays no significant lipid preference in homogeneous binary lipid mixtures in the fluid phase, even when using lipids that by themselves show very different solubilization kinetics. By contrast, in heterogeneous phase-separated bilayers, SMA was found to have a strong preference for solubilization of lipids in the fluid phase as compared to those in either a gel phase or a liquid-ordered phase. Together the results suggest that (1) SMA is a reliable tool to characterize native interactions between membrane constituents, (2) any solubilization preference of SMA is not due to properties of individual lipids but rather due to properties of the membrane or membrane domains in which these lipids reside and (3) exploiting SMA resistance rather than detergent resistance may be an attractive approach for the isolation of ordered domains from biological membranes.

  19. Physical characterization and antioxidant activity of thymol solubilized Tween 80 micelles

    NASA Astrophysics Data System (ADS)

    Deng, Ling-Li; Taxipalati, Maierhaba; Que, Fei; Zhang, Hui

    2016-12-01

    Attempts were made to solubilize thymol in Tween 80 micelle to study the solubilization mechanism of thymol and the effect of solubilization on its antioxidant activity. The maximum solubilized concentration of thymol in a 2.0% (w/v) Tween 80 micelle solution is 0.2 wt%. There was no significant difference in Z-average diameter between the empty micelles and thymol solubilized micelles. 1H NMR spectra indicated that 3-H and 4-H on the benzene ring of thymol interacted with the ester group between the hydrophilic head group and the hydrophobic tail group of Tween 80 by Van der Waals’ force. Ferric reducing antioxidant potential (FRAP) and cupric ion reducing antioxidant capacity (CUPRAC) assays showed that the reducing antioxidant activity of free thymol did not change after solubilized in Tween 80 micelles. Compared to free thymol, the solubilized thymol showed higher activities to scavenge DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl radicals. The present study suggested a possible preparation of thymol-carrying micelles with enhanced antioxidant activities that could be applied in food beverages.

  20. Physical characterization and antioxidant activity of thymol solubilized Tween 80 micelles

    PubMed Central

    Deng, Ling-Li; Taxipalati, Maierhaba; Que, Fei; Zhang, Hui

    2016-01-01

    Attempts were made to solubilize thymol in Tween 80 micelle to study the solubilization mechanism of thymol and the effect of solubilization on its antioxidant activity. The maximum solubilized concentration of thymol in a 2.0% (w/v) Tween 80 micelle solution is 0.2 wt%. There was no significant difference in Z-average diameter between the empty micelles and thymol solubilized micelles. 1H NMR spectra indicated that 3-H and 4-H on the benzene ring of thymol interacted with the ester group between the hydrophilic head group and the hydrophobic tail group of Tween 80 by Van der Waals’ force. Ferric reducing antioxidant potential (FRAP) and cupric ion reducing antioxidant capacity (CUPRAC) assays showed that the reducing antioxidant activity of free thymol did not change after solubilized in Tween 80 micelles. Compared to free thymol, the solubilized thymol showed higher activities to scavenge DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl radicals. The present study suggested a possible preparation of thymol-carrying micelles with enhanced antioxidant activities that could be applied in food beverages. PMID:27905567

  1. Phosphate Solubilization Potential of Rhizosphere Fungi Isolated from Plants in Jimma Zone, Southwest Ethiopia

    PubMed Central

    Elias, Firew

    2016-01-01

    Phosphorus (P) is one of the major bioelements limiting agricultural production. Phosphate solubilizing fungi play a noteworthy role in increasing the bioavailability of soil phosphates for plants. The present study was aimed at isolating and characterizing phosphate solubilizing fungi from different rhizospheres using both solid and liquid Pikovskaya (PVK) medium. A total of 359 fungal isolates were obtained from 150 rhizosphere soil samples of haricot bean, faba bean, cabbage, tomato, and sugarcane. Among the isolates, 167 (46.52%) solubilized inorganic phosphate. The isolated phosphate solubilizing fungi belonged to genera of Aspergillus (55.69%), Penicillium spp. (23.35%), and Fusarium (9.58%). Solubilization index (SI) ranged from 1.10 to 3.05. Isolates designated as JUHbF95 (Aspergillus sp.) and JUFbF59 (Penicillium sp.) solubilized maximum amount of P 728.77 μg·mL−1 and 514.44 μg mL−1, respectively, from TCP (tricalcium phosphate) after 15 days of incubation. The highest (363 μg mL−1) soluble-P was released from RP with the inoculation of JUHbF95 in the PVK broth after 10 days of incubation. The present study indicated the presence of diverse plant associated P-solubilizing fungi that may serve as potential biofertilizers. PMID:27688771

  2. Physical characterization and antioxidant activity of thymol solubilized Tween 80 micelles.

    PubMed

    Deng, Ling-Li; Taxipalati, Maierhaba; Que, Fei; Zhang, Hui

    2016-12-01

    Attempts were made to solubilize thymol in Tween 80 micelle to study the solubilization mechanism of thymol and the effect of solubilization on its antioxidant activity. The maximum solubilized concentration of thymol in a 2.0% (w/v) Tween 80 micelle solution is 0.2 wt%. There was no significant difference in Z-average diameter between the empty micelles and thymol solubilized micelles. (1)H NMR spectra indicated that 3-H and 4-H on the benzene ring of thymol interacted with the ester group between the hydrophilic head group and the hydrophobic tail group of Tween 80 by Van der Waals' force. Ferric reducing antioxidant potential (FRAP) and cupric ion reducing antioxidant capacity (CUPRAC) assays showed that the reducing antioxidant activity of free thymol did not change after solubilized in Tween 80 micelles. Compared to free thymol, the solubilized thymol showed higher activities to scavenge DPPH (2,2-diphenyl-1-picrylhydrazyl) and hydroxyl radicals. The present study suggested a possible preparation of thymol-carrying micelles with enhanced antioxidant activities that could be applied in food beverages.

  3. Empigen BB: a useful detergent for solubilization and biochemical analysis of keratins.

    PubMed

    Lowthert, L A; Ku, N O; Liao, J; Coulombe, P A; Omary, M B

    1995-01-05

    Intermediate filament (IF) proteins make up some of the most insoluble proteins known, and within the IF protein family, keratins are the least soluble. We compared the efficiency of nonionic, cationic, mixed nonionic and anionic, and zwitterionic detergents in solubilizing keratins from insect cells that express recombinant human keratins and from human colonic cell lines and normal keratinocytes. The cationic detergent cetyltrimethylammonium bromide was similar to the zwitterionic detergent Empigen BB in its ability to efficiently solubilize keratins, but the latter detergent was superior in that it maintained antibody reactivity and allowed for immunoprecipitation of the keratins. Although Nonidet-P40 partially solubilizes keratins, Empigen BB solubilizes a significant amount of keratins not solubilized by Nonidet-P40. In the case of vimentin, differences in solubilization efficiency among the detergents was not as dramatic as with keratins. Our results show that Empigen BB solubilizes a significant amount of epidermal and glandular keratins while preserving antigenicity. This detergent should prove useful for carrying out biochemical and molecular studies on these proteins and may be similarly beneficial for other IF proteins.

  4. Derepression of Mineral Phosphate Solubilization Phenotype by Insertional Inactivation of iclR in Klebsiella pneumoniae

    PubMed Central

    Pandya, Maharshi; Jog, Rahul; G, Naresh Kumar; Rajkumar, Shalini

    2015-01-01

    The mode of succinate mediated repression of mineral phosphate solubilization and the role of repressor in suppressing phosphate solubilization phenotype of two free-living nitrogen fixing Klebsiella pneumoniae strains was studied. Organic acid mediated mineral phosphate solubilization phenotype of oxalic acid producing Klebsiella pneumoniae SM6 and SM11 were transcriptionally repressed by IclR in presence of succinate as carbon source. Oxalic acid production and expression of genes of the glyoxylate shunt (aceBAK) was found only in glucose but not in succinate- and glucose+succinate-grown cells. IclR, repressor of aceBAK operon, was inactivated using an allelic exchange system resulting in derepressed mineral phosphate solubilization phenotype through constitutive expression of the glyoxylate shunt. Insertional inactivation of iclR resulted in increased activity of the glyoxylate shunt enzymes even in succinate-grown cells. An augmented phosphate solubilization up to 54 and 59% soluble phosphate release was attained in glucose+succinate-grown SM6Δ and SM11Δ strains respectively, compared to glucose-grown cells, whereas phosphate solubilization was absent or negligible in wildtype cells grown in glucose+succinate. Both wildtype and iclR deletion strains showed similar indole-3-acetic acid production. Wheat seeds inoculated with wildtype SM6 and SM11 improved both root and shoot length by 1.2 fold. However, iclR deletion SM6Δ and SM11Δ strains increased root and shoot length by 1.5 and 1.4 folds, respectively, compared to uninoculated controls. The repressor inactivated phosphate solubilizers better served the purpose of constitutive phosphate solubilization in pot experiments, where presence of other carbon sources (e.g., succinate) might repress mineral phosphate solubilization phenotype of wildtype strains. PMID:26381651

  5. Effect of surfactant solubilization on biodegradation of polychlorinated biphenyl congeners by Pseudomonas LB400.

    PubMed

    Billingsley, K A; Backus, S M; Ward, O P

    1999-08-01

    A variety of commercial surfactants were tested to determine their effect on polychlorinated biphenyl (PCB) transformation by Pseudomonas LB400. Initial tests determined that most surfactants were fully or partially able to solubilize the PCB congeners 2,5,2'-chlorobiphenyl (CBP), 2,4,2',4'-CBP, 2,3,5,2',5'-CBP and 2,4,5,2',4',5'-CBP, at concentrations above the surfactants' critical micelle concentration (CMC). Surfactants were also found to have no negative effect on bacterial survival, as cell numbers were the same or higher after incubation in the presence of surfactants than after incubation without surfactants. A comparison of the extent of biotransformation of single PCB congeners by the bacterium revealed that, at surfactant concentrations above the CMC, the presence of an anionic surfactant promoted while nonionic surfactants inhibited PCB transformation, compared to a control with no surfactant. The rates of transformation of PCB congeners were also higher in the presence of the anionic surfactant compared to the control. The inhibitory effects of a nonionic surfactant, Igepal CO-630 at a concentration above its CMC, on transformation of 2,4,5,2',5'-CBP could be eliminated by diluting the surfactant/PCB solution to a concentration close to the surfactant CMC.

  6. Solubilization Behavior of Polyene Antibiotics in Nanomicellar System: Insights from Molecular Dynamics Simulation of the Amphotericin B and Nystatin Interactions with Polysorbate 80.

    PubMed

    Mobasheri, Meysam; Attar, Hossein; Rezayat Sorkhabadi, Seyed Mehdi; Khamesipour, Ali; Jaafari, Mahmoud Reza

    2015-12-24

    -core compatibility in detergent micelles. Based on the obtained results, the dearth of water at interior sites of micelle and the large lateral occupation space of PAs lead to shallow insertion, broad radial distribution, and lack of core interactions of the amphiphilic drugs. Hence, controlled promotion of micelle permeability and optimization of chain crowding in palisade layer may help to achieve more efficient solubilization of the PAs.

  7. Effects of temperature and glucose limitation on coal solubilization by Candida ML13

    SciTech Connect

    Evans, B. )

    1991-04-01

    Biological processing has received considerable attention in recent years as a technology for the utilization of low-ranked coals. Several fungi and actinomycetes have been shown to liquefy highly oxidized coal in pure culture under aerobic conditions. This report describes the optimization of cultural conditions for coal solubilization by Candida sp. ML13, an organism originally isolated from a naturally weathered coal seam. Coal solubilization by surface cultures of Candida sp. has previously been demonstrated. The author describes here the elicitation of the activity in submerged cultures as well as the effect of carbohydrate concentration, carbon source, temperature, and agitation rate on coal solubilization by this organism.

  8. Antibiotics in microbial coculture.

    PubMed

    Ueda, Kenji; Beppu, Teruhiko

    2017-04-01

    Today, the frequency of discovery of new antibiotics in microbial culture is significantly decreasing. The evidence from whole-genome surveys suggests that many genes involved in the synthesis of unknown metabolites do exist but are not expressed under conventional cultivation conditions. Therefore, it is urgently necessary to study the conditions that make otherwise silent genes active in microbes. Here we overview the knowledge on the antibiotic production promoted by cocultivation of multiple microbial strains. Accumulating evidence indicates that cocultivation can be an effective way to stimulate the production of substances that are not formed during pure cultivation. Characterization of the promotive factors produced by stimulator strains is expected to give clues to the development of effective cultivation conditions for drug discovery.

  9. DNA damage primes the type I interferon system via the cytosolic DNA sensor STING to promote anti-microbial innate immunity.

    PubMed

    Härtlova, Anetta; Erttmann, Saskia F; Raffi, Faizal Am; Schmalz, Anja M; Resch, Ulrike; Anugula, Sharath; Lienenklaus, Stefan; Nilsson, Lisa M; Kröger, Andrea; Nilsson, Jonas A; Ek, Torben; Weiss, Siegfried; Gekara, Nelson O

    2015-02-17

    Dysfunction in Ataxia-telangiectasia mutated (ATM), a central component of the DNA repair machinery, results in Ataxia Telangiectasia (AT), a cancer-prone disease with a variety of inflammatory manifestations. By analyzing AT patient samples and Atm(-/-) mice, we found that unrepaired DNA lesions induce type I interferons (IFNs), resulting in enhanced anti-viral and anti-bacterial responses in Atm(-/-) mice. Priming of the type I interferon system by DNA damage involved release of DNA into the cytoplasm where it activated the cytosolic DNA sensing STING-mediated pathway, which in turn enhanced responses to innate stimuli by activating the expression of Toll-like receptors, RIG-I-like receptors, cytoplasmic DNA sensors, and their downstream signaling partners. This study provides a potential explanation for the inflammatory phenotype of AT patients and establishes damaged DNA as a cell intrinsic danger signal that primes the innate immune system for a rapid and amplified response to microbial and environmental threats.

  10. Dietary green-plant thylakoids decrease gastric emptying and gut transit, promote changes in the gut microbial flora, but does not cause steatorrhea.

    PubMed

    Stenblom, Eva-Lena; Weström, Björn; Linninge, Caroline; Bonn, Peter; Farrell, Mary; Rehfeld, Jens F; Montelius, Caroline

    2016-01-01

    Green-plant thylakoids increase satiety by affecting appetite hormones such as ghrelin, cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1). The objective of this study was to investigate if thylakoids also affect gastrointestinal (GI) passage and microbial composition. To analyse the effects on GI passage, 16 rats were gavage-fed a control or thylakoid-supplemented high-fat diet (HFD) 30 min before receiving Evans blue. Another 16 rats were fed a control HFD or thylakoid HFD for two weeks prior to the intragastric challenge with Evans blue. The amount of Evans blue in the stomach and the distance of migration in the intestines after 30 min were used as a measurement of gastric emptying and intestinal transit. These were reduced by thylakoid supplementation in the acute study, and however not significantly also after the two-week diet study. The second aim of the study was to investigate if thylakoid-supplementation affects the gut microbiota and amount of faecal fat in healthy human volunteers (n = 34) receiving thylakoid or placebo treatments for three months. Microbiota was analysed using 16S rRNA gene sequencing and qPCR, and faecal fat was extracted by dichloromethane. The total bacteria, and specifically the Bacteriodes fragilis group, were increased by thylakoid treatment versus placebo, while thylakoids did not cause steatorrhea. Dietary supplementation with thylakoids thus affects satiety both via appetite hormones and GI fullness, and affects the microbial composition without causing GI adverse effects such as steatorrhea. This suggests thylakoids as a novel agent in prevention and treatment of obesity.

  11. Human plasma enhances the expression of Staphylococcal microbial surface components recognizing adhesive matrix molecules promoting biofilm formation and increases antimicrobial tolerance In Vitro

    PubMed Central

    2014-01-01

    Background Microbial biofilms have been associated with the development of chronic human infections and represent a clinical challenge given their increased antimicrobial tolerance. Staphylococcus aureus is a major human pathogen causing a diverse range of diseases, of which biofilms are often involved. Staphylococcal attachment and the formation of biofilms have been shown to be facilitated by host factors that accumulate on surfaces. To better understand how host factors enhance staphylococcal biofilm formation, we evaluated the effect of whole human plasma on biofilm formation in clinical isolates of S. aureus and the expression of seven microbial surface components recognizing adhesive matrix molecules (MSCRAMMs) known to be involved in biofilm formation by quantitative real-time PCR. We also evaluated whether plasma augmented changes in S. aureus biofilm morphology and antimicrobial resistance. Results Exposure of clinical isolates of S. aureus to human plasma (10%) within media, and to a lesser extent when coated onto plates, significantly enhanced biofilm formation in all of the clinical isolates tested. Compared to biofilms grown under non-supplemented conditions, plasma-augmented biofilms displayed significant changes in both the biofilm phenotype and cell morphology as determined by confocal scanning laser microscopy (CLSM) and scanning electron microscopy (SEM), respectively. Exposure of bacteria to plasma resulted in a significant fold-increase in MSCRAMM expression in both a time and isolate-dependent manner. Additionally, plasma-augmented biofilms displayed an increased tolerance to vancomycin compared to biofilms grown in non-supplemented media. Conclusions Collectively, these studies support previous findings demonstrating a role for host factors in biofilm formation and provide further insight into how plasma, a preferred growth medium for staphylococcal biofilm formation enhances as well as augments other intrinsic properties of S. aureus biofilms

  12. Recent Food Applications of Microbial Surfactants.

    PubMed

    Nitschke, Marcia; Silva, Sumária Sousa E

    2016-07-20

    During last years the interest on microbial surfactants or biosurfactants has gained attention due to their natural origin and environmental compatibility. These characteristics fulfill the demand of regulatory agencies and society to use of more sustained and green chemicals. Microbial-derived surfactants can replace synthetic surfactants in a great variety of industrial applications as detergents, foaming, emulsifiers, solubilizers and wetting agents. Change in trend of consumers to natural from synthetic additives and also the increasing health and environmental concerns creating demand for new "green" additives in food. Apart from their inherent surface-active properties, BS have been shown antimicrobial and antibiofilm activity against food pathogens; therefore, BS can be versatile additives or ingredients for food processing. These interesting applications will be discussed in this review.

  13. Solubilized placental membrane protein inhibits insulin receptor tyrosine kinase activity

    SciTech Connect

    Strout, H.V. Jr.; Slater, E.E.

    1987-05-01

    Regulation of insulin receptor (IR) tyrosine kinase (TK) activity may be important in modulating insulin action. Utilizing an assay which measures IR phosphorylation of angiotensin II (AII), the authors investigated whether fractions of TX-100 solubilized human placental membranes inhibited IR dependent AII phosphorylation. Autophosphorylated IR was incubated with membrane fractions before the addition of AII, and kinase inhibition measured by the loss of TSP incorporated in AII. An inhibitory activity was detected which was dose, time, and temperature dependent. The inhibitor was purified 200-fold by sequential chromatography on wheat germ agglutinin, DEAE, and hydroxyapatite. This inhibitory activity was found to correlate with an 80 KD protein which was electroeluted from preparative slab gels and rabbit antiserum raised. Incubation of membrane fractions with antiserum before the IRTK assay immunoprecipitated the inhibitor. Protein immunoblots of crude or purified fractions revealed only the 80 KD protein. Since IR autophosphorylation is crucial to IRTK activity, the authors investigated the state of IR autophosphorylation after treatment with inhibitor; no change was detected by phosphoamino acid analysis.

  14. Production of humic substances through coal-solubilizing bacteria

    PubMed Central

    Valero, Nelson; Gómez, Liliana; Pantoja, Manuel; Ramírez, Ramiro

    2014-01-01

    In this paper, the production of humic substances (HS) through the bacterial solubilization of low rank coal (LRC) was evaluated. The evaluation was carried out by 19 bacterial strains isolated in microenvironments with high contents of coal wastes. The biotransformed LRC and the HS produced were quantified in vitro in a liquid growth medium. The humic acids (HA) obtained from the most active bacterial strain were characterized via elemental composition (C, H, N, O), IR analyses, and the E4/E6 ratio; they were then compared with the HA extracted chemically using NaOH. There was LRC biotransformation ranged from 25 to 37%, and HS production ranged from 127 to 3100 mg.L−1. More activity was detected in the isolated strains of Bacillus mycoides, Microbacterium sp, Acinetobacter sp, and Enterobacter aerogenes. The HA produced by B. mycoides had an IR spectrum and an E4/E6 ratio similar to those of the HA extracted with NAOH, but their elemental composition and their degree of aromatic condensation was different. Results suggest that these bacteria can be used to exploit the LRC resulting from coal mining activities and thus produce HS in order to improve the content of humified organic matter in soils. PMID:25477925

  15. Solubilization of leonardite by an extracellular fraction from Coriolus versicolor

    SciTech Connect

    Pyne, J.W. Jr.; Stewart, D.L.; Fredrickson, J.; Wilson, B.W.

    1987-12-01

    Coriolus versicolor has previously been shown to degrade leonardite, an oxidized form of lignite. An extracellular fraction containing protein purified from a C. versicolor culture solubilized leonardite in vitro. Expression of the activity did not require the presence of leonardite and appeared during idiophase. During ion-exchange and gel filtration column chromatography, leonardite-biosolubilizing activity eluted with syringaldazine oxidase activity and with protein, as measured by A//sub 280/ and the biuret protein assay. Syringaldazine is a substrate of the polyphenol oxidase formed by C. versicolor. Comparison of leonardite-biosolubilizing activity with the effects of chelators and surface-active agents on leonardite showed that biosolubilization was not due to either surfactant or chelating ability. Heat treatment of the preparation at 60/sup 0/C for 30 min significantly reduced both syringaldazine oxidase and leonardite-biosolubilizing activities. Cyanide, azide, and thioglycolate, which are know inhibitors of syringaldazine oxidase activity of C. versicolor, also inhibited leonardite biosolubilization. From these data, we conclude that the purified protein fraction from C. versicolor contains a syringaldazine oxidase activity that participates in leonardite biosolubilization by enzymatic action.

  16. [Phosphate solubilization of Aureobasidium pullulan F4 and its mechanism].

    PubMed

    Wang, Dan; Zhan, Jing; Sun, Qing-Ye

    2014-07-01

    The Aureobasidium pullulans F4 was isolated from the rhizosphere of Hippochaete ramosissimum in Tongguanshan mine wasteland in Tongling City, Anhui Province. Liquid culture was conducted with four kinds of phosphorus sources, calcium phosphate, aluminum phosphate, ferric phosphate and rock phosphate to determine the pH, dissolved phosphorus, phosphorus in the bacteria and organic acid in the solution. The results showed that the phosphate solubilization by A. pullulans F4 varied with phosphorus sources, which decreased in order of aluminum phosphate > ferric phosphate, calcium phosphate > rock phosphate. The amounts of dissolved phosphorus in the different treatments were all higher than 200 mg x L(-1). The pH of the medium dropped immediately in 48 h, and the aluminum phosphate and ferric phosphate treatments showed a greater decrease in pH than the calcium phosphate and rock phosphate treatments. The organic acid synthesized by A. pullulans F4 included oxalic acid, citric acid and tartaric acid, and oxalic acid, among which oxalic acid was the dominated component. The phosphate dissolving capacity of A. pullulans F4 showed no significant correlation with organic acid, but significantly correlated with the pH. The available phosphorus was significantly improved with the combined application of A. pullulans F4 and glucose, suggesting A. pullulans F4 was a potent candidate for remediation of copper mine wastelands.

  17. Solubilization, Solution Equilibria, and Biodegradation of PAH's under Thermophilic Conditions

    SciTech Connect

    Viamajala, S.; Peyton, B. M.; Richards, L. A.; Petersen, J. N.

    2007-01-01

    Biodegradation rates of PAHs are typically low at mesophilic conditions and it is believed that the kinetics of degradation is controlled by PAH solubility and mass transfer rates. Solubility tests were performed on phenanthrene, fluorene and fluoranthene at 20 C, 40 C and 60 C and, as expected, a significant increase in the equilibrium solubility concentration and of the rate of dissolution of these polycyclic aromatic hydrocarbons (PAHs) was observed with increasing temperature. A first-order model was used to describe the PAH dissolution kinetics and the thermodynamic property changes associated with the dissolution process (enthalpy, entropy and Gibb's free energy of solution) were evaluated. Further, other relevant thermodynamic properties for these PAHs, including the activity coefficients at infinite dilution, Henry's law constants and octanol-water partition coefficients, were calculated in the temperature range 20-60 C. In parallel with the dissolution studies, three thermophilic Geobacilli were isolated from compost that grew on phenanthrene at 60 C and degraded the PAH more rapidly than other reported mesophiles. Our results show that while solubilization rates of PAHs are significantly enhanced at elevated temperatures, the biodegradation of PAHs under thermophilic conditions is likely mass transfer limited due to enhanced degradation rates.

  18. Co-solubilization of hydroxyproline and pectin. Is there a direct link between the two

    SciTech Connect

    Oi, Xiaoyang; Mort, A.J. )

    1990-05-01

    Extensin, a major hydroxyproline (hyp) rich glycoprotein in walls of cultured cells of dicots, is known to be very difficult to solubilize. It has been suggested that this may be because of covalent crosslinks to cell wall polysaccharides, or more recently, crosslinks between tyrosine residues of different extensin molecules to form isodityrosine. Neither of thee hypotheses has strong evidence to support it. We are attempting to solubilize fragments of extensin which contain crosslinks for subsequent characterization. Cotton suspension culture cell walls were digested with endopolygalacturonase followed by cellulase to remove homogalacturonan, and xyloglucan and cellulose, respectively. Very little extensin (as indicated by hyp) was released by those or a subsequent trypsin digestion. Treatment of the residue with anhydrous HF at {minus}73{degree}C selectively removed the arabinofuranose residues from the hydroxyproline residues and allowed trypsin to solubilize {approximately}50% of the hyp as peptides and glycopeptides. Sugars characteristic of pectin co-solubilized with hyp during the trypsin digestion.

  19. SOLUBILIZATION OF DODECANE, TETRACHLOROETHYLENE, AND 1,2-DICHLOROBENZENE IN MICELLAR SOLUTIONS OF ETHOXYLATED NONIONIC SURFACTANTS

    EPA Science Inventory

    Although surfactants have received considerable attention as a potential means for enhancing the recovery of organic compounds from the subsurface, only limited information is available regarding the micellar solubilization of common groundwater contaminants by nonionic surfactan...

  20. Isolation and characterization of phosphate-solubilizing bacteria from seagrass rhizosphere soil

    NASA Astrophysics Data System (ADS)

    Ghosh, Upasana; Subhashini, Ponnambalam; Dilipan, Elangovan; Raja, Subramanian; Thangaradjou, Thirunavukarassu; Kannan, Lakshmanan

    2012-03-01

    Phosphate-solubilizing bacterial strains (6 Nos.) were isolated from the rhizosphere soils of two seagrasses ( Halophila ovalis (R. Br.) Hook and Halodule pinifolia (Miki) Hartog) in the Vellar estuary. Experimental studies found that the strain PSSG6 was effective in phosphate solubilization with Phosphate Solubilization efficiency index E = 375 ± 8.54, followed by the strain PSSG5 with Phosphate Solubilization efficiency index E = 275 ± 27.3. Of the 6 strains isolated, the strains PSSG4 and PSSG5 belonged to the genus Bacillus, and PSSG1, PSSG2 and PSSG3 were identified as Citrobacter sp., Shigella sp., and Klebsiella sp., respectively, by conventional method, and PSSG6 was identified as Bacillus circulans using conventional and molecular methods.

  1. SURFACTANT-ENHANCED SOLUBILIZATION OF RESIDUAL DODECANE IN SOIL COLUMNS - 1. EXPERIMANTAL INVESTIGATION

    EPA Science Inventory

    The solubilization of dodecane by polyoxyethylene (20) sorbitan monooleate, a nonionic surfactant, was investigated as a potential means of recoveringnonaqueous-phase liquids from contaminated aquifers. Residual saturations of dodecane were established by injecting 14C...

  2. Changes in labeling of soluble and solubilized hippocampus proteins after a learning experiment in rats.

    PubMed

    Popov, N; Schulzeck, S; Matthies, H

    1976-01-01

    At various intervals after acquisition of a brightness discrimination in rats labeled leucine was intraventricularly applied. Hippocampus tissue was fractionated in soluble and solubilized insoluble protein fractions. Protein content and labeling of several electrophoretically resolved bands showed a biphasic time course: a first increase was observed 20 minutes after training including preferably soluble proteins, whereas a second increase (about eight hours after training) was mainly related to solubilized insoluble proteins.

  3. Microwave-assisted protein solubilization for mass spectrometry-based shotgun proteome analysis.

    PubMed

    Ye, Xiaoxia; Li, Liang

    2012-07-17

    Protein solubilization is a key step in mass spectrometry-based shotgun proteome analysis. We describe a microwave-assisted protein solubilization (MAPS) method to dissolve proteins in reagents, such as NH(4)HCO(3) and urea, with high efficiency and with an added benefit that the solubilized proteins are denatured to become more susceptible to trypsin digestion, compared to other conventional protein solubilization techniques. In this method, a sample vial containing proteins suspended in a solubilization reagent is placed inside a domestic microwave oven and subjected to microwave irradiation for 30 s, followed by cooling the sample on ice to room temperature (~40 s) and then intermittent homogenization by vortex for 2 min. This cycle of microwave irradiation, cooling, and homogenization is repeated six times. In this way, sample overheating can be avoided, and a maximum amount of protein can be dissolved. It was shown that in the case of trypsin digestion of bovine serum albumen (BSA) more peptides and higher sequence coverage could be obtained from the protein dissolved by the MAPS method than the conventional heating, sonication, or vortex method. Compared to the most commonly used vortex-assisted protein solubilization method, MAPS reduces the solubilization time significantly, increases the amount of protein dissolvable in a reagent, and increases the number of proteins and peptides identified from a proteome sample. For example, in the proteome analysis of an Escherichia coli K-12 integral membrane protein extract, the MAPS method in combination with sequential protein solubilization and shotgun two-dimensional liquid chromatography tandem mass spectrometry analysis identified a total of 1291 distinct proteins and 10363 peptides, compared to 1057 proteins and 6261 peptides identified using the vortex method. Because MAPS can be done using an inexpensive microwave oven, this method can be readily adopted.

  4. Solubilization of lipid bilayers by myristyl sucrose ester: effect of cholesterol and phospholipid head group size.

    PubMed

    Toro, C; Sanchez, S A; Zanocco, A; Lemp, E; Gratton, E; Gunther, G

    2009-02-01

    The solubilization of biological membranes by detergents has been used as a major method for the isolation and purification of membrane proteins and other constituents. Considerable interest in this field has resulted from the finding that different components can be solubilized selectively. Certain membrane constituents are incorporated into small micelles, whereas others remain in the so-called detergent-resistant membrane domains that are large enough to be separated by centrifugation. The detergent-resistant fractions contain an elevated percentage of cholesterol, and thus its interaction with specific lipids and proteins may be key for membrane organization and regulation of cellular signaling events. This report focuses on the solubilization process induced by the sucrose monoester of myristic acid, beta-D-fructofuranosyl-6-O-myristyl-alpha-D-glucopyranoside (MMS), a nonionic detergent. We studied the effect of the head group and the cholesterol content on the process. 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and dioctadecyl-dimethyl-ammonium chloride (DODAC) vesicles were used, and the solubilization process was followed using Laurdan (6-dodecanoyl-2-dimethylaminonaphthalene) generalized polarization (GP) measurements, carried out in the cuvette and in the 2-photon microscope. Our results indicate that: (i) localization of the MMS moieties in the lipid bilayer depends on the characteristics of the lipid polar head group and influences the solubilization process. (ii) Insertion of cholesterol molecules into the lipid bilayer protects it from solubilizaton and (iii) the microscopic mechanism of solubilization by MMS implies the decrease in size of the individual liposomes.

  5. Solubilization of lipid bilayers by myristyl sucrose ester: effect of cholesterol and phospholipid head group size

    PubMed Central

    Toro, C.; Sanchez, S. A.; Zanocco, A.; Lemp, E.; Gratton, E.

    2010-01-01

    The solubilization of biological membranes by detergents has been used as a major method for the isolation and purification of membrane proteins and other constituents. Considerable interest in this field has resulted from the finding that different components can be solubilized selectively. Certain membrane constituents are incorporated into small micelles, whereas others remain in the so-called detergent-resistant membrane domains that are large enough to be separated by centrifugation. The detergent resistant fractions contain an elevated percentage of cholesterol, and thus its interaction with specific lipids and proteins may be key for membrane organization and regulation of cellular signaling events. This report focuses on the solubilization process induced by the sucrose monoester of myristic acid, β-D-Fructofuranosyl-6-O-myristyl-α-D-glucopyranoside (MMS), a nonionic detergent. We studied the effect of the head group and the cholesterol content on the process. 1-Palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and Dioctadecyl dimethylammonium chloride (DODAC) vesicles were used, and the solubilization process was followed using Laurdan (6-Dodecanoyl-2-dimethylaminonaphthalene) Generalized Polarization (GP) measurements, carried out in the cuvette and in the 2-photon microscope. Our results indicate that: (i) Localization of the MMS moieties in the lipid bilayer depend on the characteristics of the lipid polar head group and influence the solubilization process. (ii) Insertion of cholesterol molecules into the lipid bilayer protects it from solubilizaton and (iii) the microscopic mechanism of solubilization by MMS implies the decrease in size of the individual liposomes. PMID:19071100

  6. Solubilization of two structurally related anticancer drugs: XK-469 and PPA.

    PubMed

    He, Yan; Tabibi, S Esmail; Yalkowsky, Samuel H

    2006-01-01

    The efficiency of a solubilization technique is determined by the physical-chemical properties of the drug. This study investigates the solubilization on two structurally related anticancer drugs, XK-469 and PPA. XK-469 is much less polar than PPA with an intrinsic solubility of 0.000274 mg/mL, which is about 10,000 fold less than that of PPA. Fortunately, its physical-chemical properties make it much more formulatable. An ionizable drug can be solubilized by pH adjustment with cosolvency, micellization, or complexation. Both XK-469 and PPA are weak acids with pKa values of 2.7 and 2.9, respectively. Thus, they can be solubilized by pH adjustment. At pH 4.55, neither cosolvency, micellization nor complexation has much effect on the solubility of PPA. However, these techniques can significantly increase the solubility of XK-469. In fact, the solubility of XK-469 in 20% HPbetaCD at pH 4.55 is 5.85 mg/mL, which is more than 20,000 times greater than its intrinsic solubility. With the solubilization descriptors obtained from the experimental data for both unionized and ionized drug species at pH 1.0 and pH 4.55, the solubility of each drug at any pH and excipient concentration can be estimated. Then, a solubilization technique can be chosen for preparing a desired final drug concentration.

  7. Dissolution, Cyclodextrin-Enhanced Solubilization, and Mass Removal of an Ideal Multicomponent Organic Liquid

    PubMed Central

    Carroll, Kenneth C.; Brusseau, Mark L.

    2010-01-01

    Laboratory experiments and mathematical modeling were conducted to examine the influence of a hydroxypropyl-beta-cyclodextrin (HPCD) solution on the dissolution of single- and three-component organic liquids. The results of batch experiments showed that HPCD-enhanced solubilization of the organic-liquid mixtures was ideal (describable using Raoult’s Law), and that solubilization-enhancement factors were independent of mixture composition. Addition of the HPCD solution to columns containing residual saturations of the organic liquid enhanced the dissolution and removal of all three compounds in the mixture. The results of the column experiments and multicomponent rate-limited dissolution modeling suggest that solubilization was ideal for both water and cyclodextrin flushing. Concomitantly, the mass-flux reduction versus mass removal behavior was ideal for all experiments. Mass transfer was increased for HPCD solubilization relative to the water flushing due to solubility and concentration-gradient enhancement. Organic-liquid composition did not significantly impact mass transfer coefficients, and fractional mass removal behavior during HPCD solubilization was nearly identical for each compound whether present as a single component or in a mixture. Additionally, mass transfer coefficients for aqueous and HPCD solubilization for single and multicomponent mixtures were not statistically different upon normalizing by the solubility enhancement factor. PMID:19233508

  8. Binding of (/sup 3/H)forskolin to solubilized preparations of adenylate cyclase

    SciTech Connect

    Nelson, C.A.; Seamon, K.B.

    1988-01-01

    The binding of (/sup 3/H)forskolin to proteins solubilized from bovine brain membranes was studied by precipitating proteins with polyethylene glycol and separating (/sup 3/H)forskolin bound to protein from free (/sup 3/H)forskolin by rapid filtration. The K/sub d/ for (/sup 3/H)forskolin binding to solubilized proteins was 14 nM which was similar to that for (/sup 3/H)forskolin binding sites in membranes from rat brain and human platelets. Forskolin analogs competed for (/sup 3/H)forskolin binding sites with the same rank potency in both brain membranes and in proteins solubilized from brain membranes. (/sup 3/H)forskolin bound to proteins solubilized from membranes with a Bmax of 38 fmolmg protein which increased to 94 fmolmg protein when GppNHp was included in the binding assay. In contrast, GppNHp had no effect on (/sup 3/H)forskolin binding to proteins solubilized from membranes preactivated with GppNHp. Solubilized adenylate cyclase from non-preactivated membranes had a basal activity of 130 pmolmgmin which was increased 7-fold by GppNHp. In contrast, adenylate cyclase from preactivated membranes had a basal activity of 850 pmolmgmin which was not stimulated by GppNHp or forskolin

  9. Solubilizing effects caused by the nonionic surfactant dodecylmaltoside in phosphatidylcholine liposomes.

    PubMed Central

    de la Maza, A; Parra, J L

    1997-01-01

    The interaction of the nonionic surfactant dodecylmaltoside (DM) with phosphatidylcholine liposomes was investigated. Permeability alterations were detected as a change in 5(6)-carboxyfluorescein released from the interior of vesicles and bilayer solubilization as a decrease in the static light scattered by liposome suspensions. This surfactant showed higher capacity to saturate and solubilize PC liposomes and greater affinity with these structures than those reported for the octyl glucoside. At subsolubilizing level an initial maximum in the bilayer/water partitioning (K) followed by an abrupt decrease of this parameter occurred as the effective molar ratio of surfactant to phospholipid in bilayers (Re) rose. However, at solubilizing level a direct dependence was established between both parameters. A direct correlation took place in the initial interaction steps (Re up to 0.28) between the growth of vesicles, their fluidity, and Re. A similar direct dependence was established during solubilization (Re range from 0.9 to 1.7) between the decrease in both the surfactant-PC aggregate size, the light scattering of the system, and Re (composition of aggregates). The fact that the free DM concentration at subsolubilizing and solubilizing levels showed values lower than and similar to its critical micelle concentration indicates that permeability alterations and solubilization were determined, respectively, by the action of surfactant monomer and by the formation of mixed micelles. Images FIGURE 3 PMID:9083670

  10. Solubilization of Waste Activated Sludge and Nitrogenous Compounds Transformation During Solubilization by Thermophilic Enzyme (S-TE) Process.

    PubMed

    Yang, Qi; Luo, Kun; Li, Xiao-ming; Zhong, Yu; Chen, Hong-bo; Yang, Guo-jing; Shi, Yan-wei; Zeng, Guang-ming

    2015-06-01

    A representative thermophilic bacterial strain (AT06-1) capable of secreting protease was isolated from thermophilic aerobic digestion reactor, and 16S rRNA gene analysis indicated that it was Bacillus sp. The isolated strain was inoculated in waste activated sludge (WAS) to evaluate the performance of solubilization by thermophilic enzyme (S-TE) process under aerobic or microaerobic conditions at different temperatures (55-70 °C). Results showed that the inoculation of specific thermophilic strain significantly affected the volatile suspended solids (VSS) removal. At the optimal temperature of 65 °C, the maximum VSS removal of 43.6 % and highest SCOD of 4475 mg/L was achieved during microaerobic S-TE process. Compared to the noninoculation, more soluble protein was released during S-TE process due to the higher protease activity associated with the protein hydrolysis originated from cell lysis. The protease activity at aerobic and microaerobic S-TE process was respectively 1.73 and 1.88 times that of the noninoculation. Ammonia was the end nitrogenous compound of protein hydrolysis during S-TE process, which was stripped from the digestion system through continuous aeration.

  11. Solubilization of an arabinan arabinosyltransferase activity from mung bean hypocotyls.

    PubMed

    Nunan, Kylie Joy; Scheller, Henrik Vibe

    2003-05-01

    The biosynthesis of polysaccharides destined for the plant cell wall and the subsequent assembly of the cell wall are poorly understood processes that are currently the focus of much research. Arabinan, a component of the pectic polysaccharide rhamnogalacturonan I, is composed of arabinosyl residues connected via various glycosidic linkages, and therefore, the biosynthesis of arabinan is likely to involve more than one arabinosyltransferase. We have studied the transfer of [(14)C]arabinose (Ara) from UDP-L-arabinopyranose onto polysaccharides using microsomal membranes isolated from mung bean (Vigna radiata) hypocotyls. [(14)C]arabinosyl and [(14)C]xylosyl residues were incorporated into endogenous products due to the presence of UDP-Xyl-4-epimerase activity. Enzymatic digestion of endogenous products with endo-arabinanase released very little radiolabeled sugars, whereas digestion with arabinofuranosidase released some [(14)C]Ara. Microsomal membranes solubilized with the detergent octyl glucoside were able to add a single [(14)C]Ara residue onto (1-->5)-linked alpha-L-arabino-oligosaccharide acceptors. The reaction had a pH optimum of 6.5 and a requirement for manganese ions. However, enzymatic digestion of the radiolabeled oligosaccharides with endo-arabinanase and arabinofuranosidases could not fully release the radiolabeled Ara residue, indicating that the [(14)C]Ara residue was not a (1-->2)-, (1-->3)-, or (1-->5)-linked alpha-L-arabinofuranosyl residue. Rather, mild acid treatment of the product suggested that the radiolabeled Ara residue was in a pyranose conformation, and this result was confirmed by thin-layer chromatography of radiolabeled partially methylated sugars. Using microsomal membranes separated on a discontinuous sucrose gradient, the arabinosyltransferase activity appears to be mainly localized to Golgi membranes.

  12. Solubilization of active (H+ + K+)-ATPase from gastric membrane.

    PubMed

    Soumarmon, A; Grelac, F; Lewin, M J

    1983-08-10

    (H+ + K+)-ATPase-enriched membranes were prepared from hog gastric mucosa by sucrose gradient centrifugation. These membranes contained Mg2+-ATPase and p-nitrophenylphosphatase activities (68 +/- 9 mumol Pi and 2.9 +/- 0.6 mumol p-nitrophenol/mg protein per h) which were insensitive to ouabain and markedly stimulated by 20 mM KCl (respectively, 2.2- and 14.8-fold). Furthermore, the membranes autophosphorylated in the absence of K+ (up to 0.69 +/- 0.09 nmol Pi incorporated/mg protein) and dephosphorylated by 85% in the presence of this ion. Membrane proteins were extracted by 1-2% (w/v) n-octylglucoside into a soluble form, i.e., which did not sediment in a 100 000 X g X 1 h centrifugation. This soluble form precipitated upon further dilution in detergent-free buffer. Extracted ATPase represented 32% (soluble form) and 68% (precipitated) of native enzyme and it displayed the same characteristic properties in terms of K+-stimulated ATPase and p-nitrophenylphosphatase activities and K+-sensitive phosphorylation: Mg2+-ATPase (mumol Pi/mg protein per h) 32 +/- 9 (basal) and 86 +/- 20 (K+-stimulated); Mg2+-p-nitrophenylphosphatase (mumol p-nitrophenol/mg protein per h) 2.6 +/- 0.5 (basal) and 22.2 +/- 3.2 (K+-stimulated); Mg2+-phosphorylation (nmol Pi/mg protein) 0.214 +/- 0.041 (basal) and 0.057 +/- 0.004 (in the presence of K+). In glycerol gradient centrifugation, extracted enzyme equilibrated as a single peak corresponding to an apparent 390 000 molecular weight. These findings provide the first evidence for the solubilization of (H+ + K+)-ATPase in a still active structure.

  13. Plant growth promotion traits of phosphobacteria isolated from Puna, Argentina.

    PubMed

    Viruel, Emilce; Lucca, María E; Siñeriz, Faustino

    2011-07-01

    The ability of soil microorganisms to solubilize phosphate is an important trait of plant growth-promoting bacteria leading to increased yields and smaller use of fertilizers. This study presents the isolation and characterization of phosphobacteria from Puna, northwestern Argentina and the ability to produce phosphate solubilization, alkaline phosphatase, siderophores, and indole acetic acid. The P-solubilizing activity was coincidental with a decrease in pH values of the tricalcium phosphate medium for all strains after 72 h of incubation. All the isolates showed the capacity to produce siderophores and indoles. Identification by 16S rDNA sequencing and phylogenetic analysis revealed that these strains belong to the genera Pantoea, Serratia, Enterobacter, and Pseudomonas. These isolates appear attractive for exploring their plant growth-promoting activity and potential field application.

  14. The fate of P solubilization during decomposition of soil organic matter as regulated by drying-rewetting and freeze - thawing events

    NASA Astrophysics Data System (ADS)

    Yevdokimov, llya; Blagodatskaya, Evgenia

    2015-04-01

    Drying-rewetting and freeze-thawing events are known to provoke solubilization of nutrients in soil. However, immobilization-mineralization cycles of such an important nutrient as phosphorus under these abiotic perturbations are still poorly understandable, mainly because the P pulses are often disguised by fast processes of P sorption on soil particles. Our research aimed to elucidate the P release and its uptake by soil microorganisms depending on drying-rewetting and freeze-thawing events. The effect of abiotic factors was studied in incubation experiments with soil sampled from four soil types: Podzol (Corg 3.3%, pHH2O 3.5), Phaeozem (Corg 1.4%, pHH2O 5.6), Chernozem (Corg 3.4%, pHH2O 6.9), and Calcisol (Corg 1.9%, pHH2O 8.3). Three treatments were used: control (soil incubated at 22oC and 70% WHC), drying-rewetting (DRW) and freeze-thawing (FTH). Air-drying in DRW treatment was provided at 22oC temperature during 12 h, followed by 6 d exposition at this temperature, rewetting to 70% WHC and measuring water-extractable and microbial P pools 12 h after rewetting. Soil in FTH treatment was exposed to freezing at -10oC, 6 d exposition at the same temperature and 12 h thawing at 4oC followed by the same analytical procedures as for DRW treatment. Microbial and water extractable P pools were analyzed in control soil in parallel with those in DRW and FTH. Soil in all the treatments was labeled with a spike of 33P- orthophosphate. Microbial P was determined using the "direct" fumigation-extraction where 24 h exposition of soil to chloroform vapors was substituted by direct water/chloroform extraction; both water extractable and microbial P were analyzed after sorption on anion-exchange membranes. Despite the variability of soil pH and Corg content, all the soil types tested demonstrated similar trends: freeze-thawing led to increase in water extractable 33P, while soil in DRW treatments had lower 33P values compare to control. Microbial 33P followed the pattern FTH

  15. Solubilization of Polycyclic Aromatic Hydrocarbons by Single and Binary Mixed Rhamnolipid-Sophorolipid Biosurfactants.

    PubMed

    Song, Dandan; Liang, Shengkang; Yan, Lele; Shang, Yujun; Wang, Xiuli

    2016-07-01

    Biosurfactants are promising additives for surfactant enhanced remediation (SER) technologies due to their low toxicity and high biodegradability. To develop green and efficient additives for SER, the aqueous solubility enhancements of polycyclic aromatic hydrocarbons (PAHs; naphthalene, phenanthrene, and pyrene) by rhamnolipid (RL) and sophorolipid (SL) biosurfactants were investigated in single and binary mixed systems. The solubilization capacities were quantified in terms of the solubility enhancement factor, molar solubilization ratio (MSR), and micelle-water partition coefficient (). Rughbin's model was applied to evaluate the interaction parameters (β) in the mixed RL-SL micelles. The solubility of the PAHs increased linearly with the glycolipid concentration above the critical micelle concentration (CMC) in both single and mixed systems. Binary RL-SL mixtures exhibited greater solubilization than individual glycolipids. At a SL molar fraction of 0.7 to 0.8, the solubilization capacity was the greatest, and the MSR and reached their maximum values, and β values became positive. These results suggest that the two biosurfactants act synergistically to increase the solubility of the PAHs. The solubilization capacity of the RL-SL mixtures increased with increasing temperature and decreased with increasing salinity. The aqueous solubility of phenanthrene reached a maximum value at pH of 5.5. Moreover, the mixed RL-SL systems exhibited a strong ability to solubilize PAHs, even in the presence of heavy metal ions. These mixed biosurfactant systems have the potential to improve the performance of SER technologies using biosurfactants to solubilize hydrophobic organic contaminants by decreasing the applied biosurfactant concentration, which reduces the costs of remediation.

  16. Extractive microbial fermentation in cloud point system.

    PubMed

    Wang, Zhilong; Dai, Zewen

    2010-05-05

    Extractive microbial fermentation of organic compounds in liquid-liquid two-phase systems is a potential strategy to overcome the limitations of microbial fermentation in an aqueous solution, such as low substrate solubility, substrate/product inhibition and product further degradation. A conventional aqueous-organic solvent two-phase system is inaccessible to extractive fermentation of a relatively high polar bioproduct as the confliction between the biocompatibility and the extraction ability of the corresponding organic solvent. An exploitation of cloud point system as a novel medium engineering method for extractive microbial fermentation is reviewed in present work. The relationship between phase separation of nonionic surfactant aqueous solution forming cloud point system and its corresponding biocompatibility to microorganisms, and the relationship between solubilization and bioavailability of organic compounds in a cloud point system are discussed. Paradigms of extractive microbial fermentation in cloud point system are highlighted with some cases in our lab. The downstream processing for nonionic surfactant recovery and product separation with microemulsion extraction is also presented.

  17. Surfactant-enhanced solubilization of tetrachloroethylene and degradation products in pump-and-treat remediation. Book chapter

    SciTech Connect

    West, C.C.

    1992-01-01

    Experiments were conducted to investigate the enhanced solubilization of tetrachloroethylene (PCE), trichloroethylene (TCE), and 1,2-dichloroethylene (DCE) in nonionic surfactant solutions of Triton X-100, Brij-30, Igepal CA-720, and Tergitol NP-10 (alkylpolyoxyethylenes). Surfactant solubilization is being considered as a means to enhance mobile phase solubilities of ground-water contaminants for the purpose of improving the efficiency of pump and treat remediation. The primary objectives of the study were to observe the solubilization of relatively hydrophilic organic solutes at system temperatures similar to ground-water conditions and to determine if solubilization can be linearly correlated to the octanol/water partition coefficient, as has been observed by others for hydrophobic organic solutes. The results of the study show that surfactant solubilization of hydrophilic solutes is highly correlated with their octanol/water partition coefficient when corrected for temperature effects. It was also observed that there appears to be little difference in solubilizing efficiency between the four surfactants.

  18. The microbial ecology of permafrost.

    PubMed

    Jansson, Janet K; Taş, Neslihan

    2014-06-01

    Permafrost constitutes a major portion of the terrestrial cryosphere of the Earth and is a unique ecological niche for cold-adapted microorganisms. There is a relatively high microbial diversity in permafrost, although there is some variation in community composition across different permafrost features and between sites. Some microorganisms are even active at subzero temperatures in permafrost. An emerging concern is the impact of climate change and the possibility of subsequent permafrost thaw promoting microbial activity in permafrost, resulting in increased potential for greenhouse-gas emissions. This Review describes new data on the microbial ecology of permafrost and provides a platform for understanding microbial life strategies in frozen soil as well as the impact of climate change on permafrost microorganisms and their functional roles.

  19. Microbial Infection and Rheumatoid Arthritis

    PubMed Central

    Li, Song; Yu, Yangsheng; Yue, Yinshi; Zhang, Zhixin; Su, Kaihong

    2014-01-01

    Rheumatoid arthritis (RA) is a complex autoimmune disease affecting 1–2% of general worldwide population. The etiopathogenesis of RA involves the interplay of multiple genetic risk factors and environmental triggers. Microbial infections are believed to play an important role in the initiation and perpetuation of RA. Recent clinical studies have shown the association of microbial infections with RA. Accumulated studies using animal models have also found that microbial infections can induce and/or exaggerate the symptoms of experimental arthritis. In this review, we have identified the most common microbial infections associated with RA in the literature and summarized the current evidence supporting their pathogenic role in RA. We also discussed the potential mechanisms whereby infection may promote the development of RA, such as generation of neo-autoantigens, induction of loss of tolerance by molecular mimicry, and bystander activation of the immune system. PMID:25133066

  20. Human erythrocytes inhibit complement-mediated solubilization of immune complexes by human serum

    SciTech Connect

    Dorval, B.L.

    1987-01-01

    The aim of this study was to develop an autologus human system to evaluate the effects of human erythrocytes on solubilization of immune complex precipitates (IC) by human serum. Incubation of IC with fresh human serum or guinea pig serum resulted in solubilization of IC. When packed erythrocytes were added to human serum or guinea pig serum binding of IC to the erythrocyte occurred and IC solubilization was inhibited significantly (p <.025). Sheep erythrocytes did not bind IC or inhibit IC solubilization. To evaluate the role of human erythrocyte complement receptor (CR1) on these findings, human erythrocytes were treated with trypsin or anti-CR1 antibodies. Both treatments abrogated IC binding to human erythrocytes but did not affect the ability of the human erythrocyte to inhibit IC solubilization. Radioimmunoassay was used to measure C3, C4 and C5 activation in human serum after incubation with IC, human erythrocytes, human erythrocytes plus IC, whole blood or in whole blood plus IC.

  1. Solubilization properties of polycyclic aromatic hydrocarbons by saponin, a plant-derived biosurfactant.

    PubMed

    Zhou, Wenjun; Yang, Juanjuan; Lou, Linjie; Zhu, Lizhong

    2011-05-01

    The enhanced solubilization of polycyclic aromatic hydrocarbons (PAHs) by saponin, a plant-derived non-ionic biosurfactant, was investigated. The results indicated that the solubilization capabilities of saponin for PAHs were greater than some representative synthetic non-ionic surfactants and showed strong dependence on solution pH and ionic strength. The molar solubilization ratio (MSR) of saponin for phenanthrene was about 3-6 times of those of the synthetic non-ionic surfactants, and decreased by about 70% with the increase of solution pH from 4.0 to 8.0, but increased by approximately 1 times with NaCl concentration increased from 0.01 to 1.0 M. Heavy metal ions can enhance saponin solubilization for phenanthrene and the corresponding MSR values increased by about 25% with the presence of 0.01 M of Cd2+ or Zn2+. Saponin is more effective in enhancing PAHs solubilization than synthetic non-ionic surfactants and has potential application in removing organic pollutants from contaminated soils.

  2. Protein recovery from inclusion bodies of Escherichia coli using mild solubilization process.

    PubMed

    Singh, Anupam; Upadhyay, Vaibhav; Upadhyay, Arun Kumar; Singh, Surinder Mohan; Panda, Amulya Kumar

    2015-03-25

    Formation of inclusion bodies in bacterial hosts poses a major challenge for large scale recovery of bioactive proteins. The process of obtaining bioactive protein from inclusion bodies is labor intensive and the yields of recombinant protein are often low. Here we review the developments in the field that are targeted at improving the yield, as well as quality of the recombinant protein by optimizing the individual steps of the process, especially solubilization of the inclusion bodies and refolding of the solubilized protein. Mild solubilization methods have been discussed which are based on the understanding of the fact that protein molecules in inclusion body aggregates have native-like structure. These methods solubilize the inclusion body aggregates while preserving the native-like protein structure. Subsequent protein refolding and purification results in high recovery of bioactive protein. Other parameters which influence the overall recovery of bioactive protein from inclusion bodies have also been discussed. A schematic model describing the utility of mild solubilization methods for high throughput recovery of bioactive protein has also been presented.

  3. Phosphate solubilizing ability of Emericella nidulans strain V1 isolated from vermicompost.

    PubMed

    Bhattacharya, Satya Sunder; Barman, Soma; Ghosh, Ranjan; Duary, Raj Kumar; Goswami, Linee; Mandal, Narayan C

    2013-10-01

    Phosphorus is one of the key factors that regulate soil fertility. Its deficiencies in soil are largely replenished by chemical fertilizers. The present study was aimed to isolate efficient phosphate solubilizing fungal strains from Eisenia fetida vermicompost. Out of total 30 fungal strains the most efficient phosphate solubilizing one was Emericella (Aspergillus) nidulans V1 (MTCC 11044), identified by custom sequencing of beta-tubulin gene and BLAST analysis. This strain solubilized 13 to 36% phosphate from four different rock phosphates. After three days of incubation of isolated culture with black Mussorie phosphate rock, the highest percentage of phosphate solubilization was 35.5 +/- 1.01 with a pH drop of 4.2 +/- 0.09. Kinetics of solubilization and acid production showed a linear relationship until day five of incubation. Interestingly, from zero to tenth day of incubation, solubility of soil phosphate increased gradually from 4.31 +/- 1.57 to 13.65 +/- 1.82 (mg kg(-1)) recording a maximum of 21.23 +/- 0.54 on day 45 in respect of the V1 isolate. Further, enhanced phosphorus uptake by Phaseolus plants with significant pod yield due to soil inoculation of Emericella nidulans V1 (MTCC 11044), demonstrated its prospect as an effective biofertilizer for plant growth.

  4. Phosphorus solubilization and plant growth enhancement by arsenic-resistant bacteria.

    PubMed

    Ghosh, Piyasa; Rathinasabapathi, Bala; Ma, Lena Q

    2015-09-01

    Phosphorus is an essential nutrient, which is limited in most soils. The P solubilization and growth enhancement ability of seven arsenic-resistant bacteria (ARB), which were isolated from arsenic hyperaccumulator Pteris vittata, was investigated. Siderophore-producing ARB (PG4, 5, 6, 9, 10, 12 and 16) were effective in solubilizing P from inorganic minerals FePO4 and phosphate rock, and organic phytate. To reduce bacterial P uptake we used filter-sterilized Hoagland medium containing siderophores or phytase produced by PG12 or PG6 to grow tomato plants supplied with FePO4 or phytate. To confirm that siderophores were responsible for P release, we compared the mutants of siderophore-producing bacterium Pseudomonas fluorescens Pf5 (PchA) impaired in siderophore production with the wild type and test strains. After 7d of growth, mutant PchA solubilized 10-times less P than strain PG12, which increased tomato root biomass by 1.7 times. For phytate solubilization by PG6, tomato shoot biomass increased by 44% than control bacterium Pseudomonas chlororaphis. P solubilization by ARB from P. vittata may be useful in enhancing plant growth and nutrition in other crop plants.

  5. Ecology, Microbial

    SciTech Connect

    Konopka, Allan

    2009-03-19

    Microbial ecology is a relatively young discipline within the field of microbiology. Its modern history spans just the past 60 years, and the field is defined by its emphasis on understanding the interactions of microbes with their environment, rather than their behavior under artificial laboratory conditions. Because microbes are ubiquitous, microbial ecologists study a broad diversity of habitats that range from aquatic to terrestrial to plant- or animal-associated. This has made it a challenge to identify unifying principles within the field. One approach is to recognize that although the activity of microbes in nature have effects at the macroscale, they interact with their physical, chemical and biological milieu at a scale of micrometers. At this scale, several different microbial ecosystems can be defined, based upon association with particles, the presence of environmental gradients and the continuous availability of water. Principles applicable to microbial ecology reflect not only their population ecology and physiological ecology, but also their broad versatility and quantitative importance in the biosphere as biogeochemical catalysts and capacity for rapid physiological and evolutionary responses.

  6. Ecology, Microbial

    SciTech Connect

    Konopka, Allan

    2009-05-15

    Microbial ecology is a relatively young discipline within the field of microbiology. Its modern history spans just the past 60 years, and the field is defined by its emphasis on understanding the interactions of microbes with their environment, rather than their behavior under artificial laboratory conditions. Because microbes are ubiquitous, microbial ecologists study a broad diversity of habitats that range from aquatic to terrestrial to plant- or animal-associated. This has made it a challenge to identify unifying principles within the field. One approach is to recognize that although the activity of microbes in nature have effects at the macroscale, they interact with their physical, chemical and biological milieu at a scale of micrometers. At this scale, several different microbial ecosystems can be defined, based upon association with particles, the presence of environmental gradients and the continuous availability of water. Principles applicable to microbial ecology reflect not only their population ecology and physiological ecology, but also their broad versatility and quantitative importance in the biosphere as biogeochemical catalysts and capacity for rapid physiological and evolutionary responses.

  7. Rapid room temperature solubilization and depolymerization of polymeric lignin at high loadings

    SciTech Connect

    Sun, Jian; Dutta, Tanmoy; Parthasarathi, Ramakrishnan; Kim, Kwang Ho; Tolic, Nikola; Chu, Rosalie K.; Isern, Nancy G.; Cort, John R.; Simmons, Blake A.; Singh, Seema

    2016-01-01

    The relatively poor solubility of lignin in most pretreatment solvents remains one of the biggest challegnes in lignin valorization to improve overall biorefinery economics. In this work, rapid room temperature solubilization of lignin at high solid loadings (>30 wt%) can be easily achieved in a single step using ethylene glycol (EG). The solubilized lignin can be rapidly and quantitively recovered with the addtion of ethanol. The computational and nuclear magnetic resonance (NMR) spectroscopic studies confirm that strong hydrogen bond interactions between EG and the free hydroxyl groups present in lignin contribute to the lignin dissolution. In addition, hydrogen peroxide mediated depolymerization of dissolved lignin at low temperature (80 oC) was tested and the effect of EG molecules on depolymerization of ligin was also theoritically studied. The findings of this work provide mechanistic insights of hydrogen bond interactions in high lignin solubilization and valorization.

  8. Arginine-assisted solubilization system for drug substances: solubility experiment and simulation.

    PubMed

    Hirano, Atsushi; Kameda, Tomoshi; Arakawa, Tsutomu; Shiraki, Kentaro

    2010-10-28

    The poor aqueous solubility of drug substances hampers their broader applications. This paper describes a de novo strategy to increase the aqueous solubility of drug substances using an arginine-assisted solubilization system (AASS) with alkyl gallates as model drug substances. Solubility experiments of alkyl gallates showed that arginine greatly increases the aqueous solubility of different alkyl gallates, whose aqueous solubilities differ widely. In contrast, lysine showed marginal effects on alkyl gallates solubility. Molecular dynamic simulation indicated a greater interaction of arginine with alkyl gallates than that of lysine, which reflects favorable interaction between the guanidinium group of arginine and the aromatic ring of alkyl gallates. Such interaction apparently disrupts association of alkyl gallate molecules, leading to solubilization. These results indicate AASS as a promising approach to solubilize poorly soluble drug substances containing aromatic ring structures.

  9. Characterization of solubilized human and rat brain US -endorphin-receptor complex

    SciTech Connect

    Helmeste, D.M.; Li, C.H.

    1986-01-01

    Opioid receptors have been solubilized from human striatal and rat whole-brain membranes by use of 3-((3-cholamidopropyl)dimethylammonio)-1-propanesulfonate (CHAPS). Tritiated human US -endorphin (TH-US /sub h/-EP) binding revealed high-affinity competition by morphine, naloxone, and various US -EP analogues. Lack of high-affinity competition by (+/-)-3,4-dichloro-N-methyl-N-(2-(1-pyrrolidinyl)cyclohexyl)benzeneacetamide methanesulfonate (U50-488, Upjohn) indicated that k sites were not labeled by TH-US -/sub h/-EP under these conditions. Affinities were similar in both soluble and membrane preparations except for (Met)enkephalin, which appears to be rapidly degraded by the solubilized extract. Size differences between human and rat solubilized TH-US /sub h/-EP-receptor complexes were revealed by exclusion chromatography.

  10. Solubilization and Interaction Studies of Bile Salts with Surfactants and Drugs: a Review.

    PubMed

    Malik, Nisar Ahmad

    2016-05-01

    In this review, bile salt, bile salt-surfactant, and bile salt-drug interactions and their solubilization studies are mainly focused. Usefulness of bile salts in digestion, absorption, and excretion of various compounds and their rare properties in ordering the shape and size of the micelles owing to the presence of hydrophobic and hydrophilic faces are taken into consideration while compiling this review. Bile salts as potential bio-surfactants to solubilize drugs of interest are also highlighted. This review will give an insight into the selection of drugs in different applications as their properties get modified by interaction with bile salts, thus influencing their solution behavior which, in turn, modifies the phase-forming behavior, microemulsion, and clouding phenomenon, besides solubilization. Finally, their future perspectives are taken into consideration to assess their possible uses as bio-surfactants without side effects to human beings.

  11. Microcalorimetric investigation of the solubilization of water in reversed micelles and water-in-oil microemulsions

    SciTech Connect

    Haandrikman, G.; Daane, G.J.R.; Kerkhof, F.J.M.; Os, N.M. van; Rupert, L.A.M.

    1992-10-29

    Microcalorimetry has been used to study the solubilization of water in reversed micelles and water-in-oil (w/o) microemulsions. The systems were based on Aerosol OT (AOT) and two isomerically pure sodium alkylarenesulfonates as surfactants. The solubilization of water can be described in terms of hydration of the head group (ca. three H{sub 2}O molecules per AOT), swelling of the water droplet, and phase separation. All steps are endothermic, indicating that a gain in entropy is the driving forcing for solubilization. Above 60 {degrees}C the hydration energy for AOT is strongly affected by temperature. The swelling of alkylarenesulfonate w/o microemulsions droplets in n-heptane is more endothermic than that of AOT w/o microemulsion droplets in n-heptane, indicating a significant influence of surfactant structure. 57 refs., 7 figs., 1 tab.

  12. Solubilization of phenanthrene above cloud point of Brij 30: a new application in biodegradation.

    PubMed

    Pantsyrnaya, T; Delaunay, S; Goergen, J L; Guseva, E; Boudrant, J

    2013-06-01

    In the present study a new application of solubilization of phenanthrene above cloud point of Brij 30 in biodegradation was developed. It was shown that a temporal solubilization of phenanthrene above cloud point of Brij 30 (5wt%) permitted to obtain a stable increase of the solubility of phenanthrene even when the temperature was decreased to culture conditions of used microorganism Pseudomonas putida (28°C). A higher initial concentration of soluble phenanthrene was obtained after the cloud point treatment: 200 against 120μM without treatment. All soluble phenanthrene was metabolized and a higher final concentration of its major metabolite - 1-hydroxy-2-naphthoic acid - (160 against 85μM) was measured in the culture medium in the case of a preliminary cloud point treatment. Therefore a temporary solubilization at cloud point might have a perspective application in the enhancement of biodegradation of polycyclic aromatic hydrocarbons.

  13. New spectrophotometric estimation of indomethacin capsules with niacinamide as hydrotropic solubilizing agent

    PubMed Central

    Maheshwari, R. K.; Rathore, Amit; Agrawal, Archana; Gupta, Megha A.

    2011-01-01

    Background: Hydrotropic solubilization process involves cooperative intermolecular interaction with several balancing molecular forces, rather than either a specific complexation event or a process dominated by a medium effect, such as co-solvency or salting-in. Materials and Methods: In the present investigation, hydrotropic solution of 2 M niacinamide was employed as the solubilizing agent to solubilize the poorly water-soluble drug, indomethacin, from the capsule dosage form for spectrophotometric determination in ultraviolet region. Results: Hydrotropic agent used did not interfere in the spectrophotometric analysis. In preliminary solubility studies, it was found that there was more than fivefold enhancement in the aqueous solubility of indomethacin (poorly water-soluble drug) in 2 M niacinamide solution as compared to its aqueous solubility at 28 ± 1°C. Conclusion: The proposed method is new, simple, safe, environmentally friendly, economic, accurate and cost-effective and can be successfully employed in routine analysis. PMID:23781453

  14. Dopamine transporter; solubilization and characterization of ( sup 3 H) GBR-12935 binding in canine caudate

    SciTech Connect

    Sallee, F.R.

    1988-01-01

    The dopamine (DA) transporter protein, as indexed by ({sup 3}H)GBR-12935 binding, was solubilized from canine striatal membranes with the detergent digitonin. This solubilized protein retained the same pharmacological characteristics as membrane attached uptake sites. The binding of ({sup 3}H)GBR-12935 to solubilized preparations was specific, saturable and reversible with an equilibrium dissociation constant of approximately 3 nM and a maximum ligand binding (B{sub max}) of 3.4 pmol/mg protein. ({sup 3}H)GBR-12935 also bound to solubilized sites in a sodium-independent manner with a K{sub D} of approximately 6 nM and a B{sub max} of 1.2 {plus minus} 0.2 pmol/mg protein. Dopamine uptake inhibitors and substrates of DA uptake inhibited ({sup 3}H)GBR-12935 binding in a stereoselective and concentration dependent manner. For these compounds rank order of potency for inhibition of ({sup 3}H)GBR-12935 binding correlated with their potency for inhibition of dopamine uptake. K{sub D} values for DA uptake inhibitors in solubilized preparations correlated with those obtained on ({sup 3}H)GBR-12935 binding in the native state. The dopamine transporter appears to be a transmembrane glycoprotein by virtue of its absorption and specific elution from wheat germ agglutinin (WGA)-lectin column. Solubilization of the putative dopamine transporter with full retention of binding activity now allows for the purification and biochemical characterization of this important membrane protein.

  15. Solubilization of pentanol by cationic surfactants and binary mixtures of cationic surfactants

    SciTech Connect

    Morgan, M.E.

    1993-12-31

    The research reported here has included studies of the solubilization of pentanol in hexadecylpyridinium chloride (CPC), trimethyletetradecylammonium chloride (C{sub 14}Cl), benzyldimethyltetradecylammonium chloride (C{sub 14}BzCl), benzyldimethylhexadecylpyridinium chloride (C{sub 16}BzCl), hexadecyltrimethylammonium bromide (CTAB), and binary mixtures of CPC + C{sub 16}BzCl and C{sub 14}Cl + C{sub 14}BzCl. Rather than using calorimetric methods, this project will employ headspace chromatography to measure solubilization of pentanol over a wide range of solute concentrations. While not yielding as much thermodynamic data as calorimetry, headspace chromatography is a more direct measure of the extent of solubilization. Using headspace chromatography, is a more direct measure of the extent of solubilization. Using headspace chromatography, this study will seek to determine whether strongly synergistic mixture ratios exist in the case of binary cationic surfactant systems. There are two equilibria in the pentanol-water-surfactant system: (1) The pentanol solubilized in micelles is in equilibrium with the monomeric pentanol in solution, and (2) the monomeric pentanol is in equilibrium with the pentanol in the vapor above the solution. To establish the link between the two equilibria, a sample of the vapor above pure liquid pentanol must be collected, in order to find the activity of pentanol in solution. Also, a calibration curve for various concentrations of pentanol in solution. From this type of data it is possible to infer both the concentration of pentanol solubilized in micelles and the concentrations of pentanol in the ``bulk`` solution outside the micelles. The method is equally applicable to systems containing a single surfactant as well as mixtures of surfactants.

  16. Presenilin 1 is linked with γ-secretase activity in the detergent solubilized state

    PubMed Central

    Li, Yue-Ming; Lai, Ming-Tain; Xu, Min; Huang, Qian; DiMuzio-Mower, Jillian; Sardana, Mohinder K.; Shi, Xiao-Ping; Yin, Kuo-Chang; Shafer, Jules A.; Gardell, Stephen J.

    2000-01-01

    γ-Secretase is a membrane-associated protease that cleaves within the transmembrane region of amyloid precursor protein to generate the C termini of the two Aβ peptide isoforms, Aβ40 and Aβ42. Here we report the detergent solubilization and partial characterization of γ-secretase. The activity of solubilized γ-secretase was measured with a recombinant substrate, C100Flag, consisting largely of the C-terminal fragment of amyloid precursor protein downstream of the β-secretase cleavage site. Cleavage of C100Flag by γ-secretase was detected by electrochemiluminescence using antibodies that specifically recognize the Aβ40 or Aβ42 termini. Incubation of C100Flag with HeLa cell membranes or detergent-solubilized HeLa cell membranes generates both the Aβ40 and Aβ42 termini. Recovery of catalytically competent, soluble γ-secretase critically depends on the choice of detergent; CHAPSO (3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulfonate) but not Triton X-100 is suitable. Solubilized γ-secretase activity is inhibited by pepstatin and more potently by a novel aspartyl protease transition-state analog inhibitor that blocks formation of Aβ40 and Aβ42 in mammalian cells. Upon gel exclusion chromatography, solubilized γ-secretase activity coelutes with presenilin 1 (PS1) at an apparent relative molecular weight of approximately 2.0 × 106. Anti-PS1 antibody immunoprecipitates γ-secretase activity from the solubilized γ-secretase preparation. These data suggest that γ-secretase activity is catalyzed by a PS1-containing macromolecular complex. PMID:10801983

  17. The solubilization of fatty acids in systems based on block copolymers and nonionic surfactants

    NASA Astrophysics Data System (ADS)

    Mirgorodskaya, A. B.; Yatskevich, E. I.; Zakharova, L. Ya.

    2010-12-01

    The solubilizing action of micellar, microemulsion, and polymer-colloid systems formed on the basis of biologically compatible amphiphilic polymers and nonionic surfactants on capric, lauric, palmitic, and stearic acids was characterized quantitatively. Systems based on micelle forming oxyethyl compounds increased the solubility of fatty acids by more than an order of magnitude. Acid molecules incorporated into micelles increased their size and caused structural changes. Solubilization was accompanied by complete or partial destruction of intrinsic acid associates and an increase in their p K a by 1.5-2 units compared with water.

  18. Improving solubilization in microemulsions with additives. 1. The lipophilic linker role

    SciTech Connect

    Graciaa, A.; Lachaise, J.; Cucuphat, C. ); Bourrel, M. ); Salager, J.L. )

    1993-03-01

    Very lipophilic additives are able to substantially improve the solubilization in surfactant-oil-water microemulsions. The so-called lipophilic linker effect is studied, and its role is discussed. It is shown that the presence of a very lipophilic amphiphilic additive may improve substantially the solubilization in microemulsions. This substance is called a lipophilic linker because its preferential orientation in the oil layers next to the interface might provide some ordering of the oil molecules as well as an additional link with the surfactant. Both effects result in a higher interaction on the oil side of the interface. 21 refs., 5 figs., 1 tab.

  19. Evaluation for rock phosphate solubilization in fermentation and soil-plant system using a stress-tolerant phosphate-solubilizing Aspergillus niger WHAK1.

    PubMed

    Xiao, Chunqiao; Zhang, Huaxiang; Fang, Yujuan; Chi, Ruan

    2013-01-01

    A strain WHAK1, identified as Aspergillus niger, was isolated from Yichang phosphate mines in Hubei province of China. The fungus developed a phosphate solubilization zone on modified National Botanical Research Institute's phosphate growth (NBRIP) agar medium, supplemented with tricalcium phosphate. The fungus was applied in a repeated-batch fermentation process in order to test its effect on solubilization of rock phosphate (RP). The results showed that A. niger WHAK1 could effectively solubilize RP in NBRIP liquid medium and released soluble phosphate in the broth, which can be illustrated by the observation of scanning electron microscope, energy-dispersive X-ray microanalysis, and Fourier transform infrared spectroscopy. Acidification of the broth seemed to be the major mechanism for RP solubilization by the fungus. Indeed, multiple organic acids (mainly gluconic acid) were detected in the broth by high-performance liquid chromatography analysis. These organic acids caused a significant drop of pH and an obvious rise of titratable acidity in the broth. The fungus also exhibited high levels of tolerance against temperature, pH, salinity, and desiccation stresses, although a significant decline in the fungal growth and release of soluble phosphate was marked under increasing intensity of stress parameters. Further, the fungus was introduced into the soil supplemented with RP to analyze its effect on plant growth and phosphate uptake of wheat plants. The result revealed that inoculation of A. niger WHAK1 significantly increased the growth and phosphate uptake of wheat plants in the RP-amended soil compared to the control soil.

  20. Synthesis of a Disulfonated Derivative of Cucurbit[7]uril and Investigations of its Ability to Solubilize Insoluble Drugs

    PubMed Central

    Robinson, Elizabeth L.; Zavalij, Peter Y.; Isaacs, Lyle

    2015-01-01

    Cucurbit[7]uril (CB[7]) is currently being investigated as a solubilizing agent for insoluble drugs. We recently found that acyclic CB[n]-type receptors that bear sulfonate solubilizing groups are well suited for this application. Herein, we report cucurbit[7]uril derivative (1) that bears two sulfonate groups on its convex face that we hypothesized would be a superior solubilizing excipient for insoluble drugs. Before using 1 for drug solubilization experiments we showed that 1 does not self-associate and that it retained its ability to bind to diammonium compounds as common guests for CB[7] sized cavities. X-ray crystallography shows that 1 maintains the key structural features of CB[7] with only minor ellipsoidal deformations at the equator and carbonyl portals of 1. Unfortunately, the aqueous solubility of 1 (20 mM) is slightly lower than CB[7] (20-30 mM) which limits its potential as a solubilizing excipient for insoluble drugs. We created phase solubility diagrams for the solubilization of three drugs (camptothecin, albendazole, cinnarizine) with two different containers (1 and CB[7]). CB[7] and 1 exhibit comparable solubilization abilities (e.g. Ka and maximum solubility) toward camptothecin and albendazole but 1 is an inferior solubilizing agent for cinnarizine because of the low solubility exhibited by the 1•cinnarizine complex. PMID:25937787

  1. Microbial biosurfactants as additives for food industries.

    PubMed

    Campos, Jenyffer Medeiros; Stamford, Tânia Lúcia Montenegro; Sarubbo, Leonie Asfora; de Luna, Juliana Moura; Rufino, Raquel Diniz; Banat, Ibrahim M

    2013-01-01

    Microbial biosurfactants with high ability to reduce surface and interfacial surface tension and conferring important properties such as emulsification, detergency, solubilization, lubrication and phase dispersion have a wide range of potential applications in many industries. Significant interest in these compounds has been demonstrated by environmental, bioremediation, oil, petroleum, food, beverage, cosmetic and pharmaceutical industries attracted by their low toxicity, biodegradability and sustainable production technologies. Despite having significant potentials associated with emulsion formation, stabilization, antiadhesive and antimicrobial activities, significantly less output and applications have been reported in food industry. This has been exacerbated by uneconomical or uncompetitive costing issues for their production when compared to plant or chemical counterparts. In this review, biosurfactants properties, present uses and potential future applications as food additives acting as thickening, emulsifying, dispersing or stabilising agents in addition to the use of sustainable economic processes utilising agro-industrial wastes as alternative substrates for their production are discussed.

  2. DIRECT AND PHOTOACTIVATED TOXICITY OF A COMPLEX PETROLEUM MIXTURE: A COMPARISON OF SOLUBILIZATION METHODS

    EPA Science Inventory

    This work addresses several issues associated with the toxicity of a complex petroleum mixture (combined kerosene/diesel and crude oil), including developmental effects and early lifestage mortality, method of solubilization, and potential photo-activated and photo-modified toxic...

  3. Sub-CMC solubilization of dodecane by rhamnolipid in saturated porous media

    NASA Astrophysics Data System (ADS)

    Zhong, Hua; Zhang, Hui; Liu, Zhifeng; Yang, Xin; Brusseau, Mark L.; Zeng, Guangming

    2016-09-01

    Experiments were conducted with a two-dimensional flow cell to examine the effect of monorhamnolipid surfactant at sub-CMC concentrations on solubilization of dodecane in porous media under dynamic flow conditions. Quartz sand was used as the porous medium and artificial groundwater was used as the background solution. The effectiveness of the monorhamnolipid was compared to that of SDBS, Triton X-100, and ethanol. The results demonstrated the enhancement of dodecane solubility by monorhamnolipid surfactant at concentrations lower than CMC. The concentrations (50–210 μM) are sufficiently low that they do not cause mobilization of the dodecane. Retention of rhamnolipid in the porous medium and detection of nano-size aggregates in the effluent show that the solubilization is based on a sub-CMC aggregate-formation mechanism, which is significantly stronger than the solubilization caused by the co-solvent effect. The rhamnolipid biosurfactant is more efficient for the solubilization compared to the synthetic surfactants. These results indicate a strategy of employing low concentrations of rhamnolipid for surfactant-enhanced aquifer remediation (SEAR), which may overcome the drawbacks of using surfactants at hyper-CMC concentrations.

  4. Biorelevant media simulating fed state intestinal fluids: colloid phase characterization and impact on solubilization capacity.

    PubMed

    Kleberg, Karen; Jacobsen, Freja; Fatouros, Dimitris G; Müllertz, Anette

    2010-08-01

    The purpose of the present study was to study the impact of free fatty acid and monoglyceride level and ratio on the nanostructural composition and solubilizing capacity of media simulating fed state intestinal fluids (SIFs). SIFs, without or with oleic acid/monoolein (OA/MO) in ratios of 2:1 or 6:1 were composed and characterized by surface tension, dynamic light scattering, and cryogenic transmission electron microscopy. Additionally solubilizing capacities towards three poorly water-soluble compounds: danazol, fenofibrate, and cinnarizine, were assessed. The surface tension of the media was not affected by the OA/MO ratio but only determined by the total surfactant concentration. The media with no lipolysis products only contained micelles, whereas media with lipolysis products also contained vesicles and other colloidal structures. The structures in the 6:1 media were more numerous and more well-defined regarding shape and size. The nanostructural composition of the media did influence the solubilizing capacity toward fenofibrate and cinnarizine, but not toward danazol. The relative composition of SIFs is important for the solubilizing capacity of some drug compounds. The findings in this study suggest that the affinity of the drug to the different colloidal structures is determining for the solubility of the compound in the media.

  5. Phagocytosis and solubilization of fixed cells by metastatic hamster embryo fibroblasts, Nil2C2

    SciTech Connect

    Sakiyama, H.; Nishino, Y.; Nishimura, K.; Noda, Y.; Otsu, H.

    1984-05-01

    When Nil2C2, a metastatic clone derived from hamster embryo fibroblasts (Nil), was inoculated over (/sup 3/H)leucine-labeled fixed cells, Nil2C2 cells solubilized and phagocytosed fixed cells, and the radioactivity was released into the culture medium as trichloroacetic acid-soluble fragments. The solubilization of fixed cells was dependent on both the time of incubation of living cells with fixed cells and the number of living cells inoculated. Nil2C2 cells were shown by autoradiographic and electron microscopic studies to peel off fixed cells and ingest them as large fragments. The solubilization of fixed cells was significantly decreased when plasminogen was depleted from the culture medium. Protease inhibitors such as leupeptin, epsilon-aminocaproic acid, and soybean trypsin inhibitor partially inhibited the proteolysis and phagocytosis of Nil2C2 cells. Mouse peritoneal macrophages activated by Salmonella typhimurium solubilized fixed cells after the addition of 12-O-tetradecanoylphorbol-13-acetate. However, they did not phagocytose fixed cells as large fragments.

  6. Different behaviours in the solubilization of polycyclic aromatic hydrocarbons in water induced by mixed surfactant solutions.

    PubMed

    Sales, Pablo S; de Rossi, Rita H; Fernández, Mariana A

    2011-09-01

    Water solubility of polycyclic aromatic hydrocarbons (PAHs), viz, naphthalene and phenanthrene, in micellar solutions at 25°C was investigated, using two series of different binary mixtures of anionic and nonionic surfactants. Tween 80 and Brij-35 were used as nonionic surfactants whereas fatty acids or amphiphilic cyclodextrins (Mod-β-CD) synthesized in our laboratory were used as anionic ones. Solubilization capacity has been quantified in terms of the molar solubilization ratio and the micelle-water partition coefficient, using UV-visible spectrophotometry. Anionic surfactants exhibited less solubilization capacity than nonionics. The mixtures between Tween 80 and Mod-β-CD did not show synergism to increase the solubilization of PAHs. On the other hand, the mixtures formed by Tween 80 and fatty acids at all mole fractions studied produced higher enhancements of the solubility of naphthalene than the individual surfactants. The critical micellar concentration of the mixtures of Tween 80/sodium laurate was determined by surface tension measurements and spectrofluorimetry using pyrene as probe. The system is characterized by a negative interaction parameter (β) indicating attractive interactions between both surfactants in the range of the compositions studied.

  7. The apparent solubilizing capacity of simulated intestinal fluids for poorly water-soluble drugs.

    PubMed

    Schwebel, Hervé J; van Hoogevest, Peter; Leigh, Mathew L S; Kuentz, Martin

    2011-06-01

    Drug solubility testing in biorelevant media has become an indispensable tool in pharmaceutical development. Despite this importance, there is still an incomplete understanding of how poorly soluble compounds interact with these media. The aim of this study was to apply the concept of the apparent solubilization capacity to fasted and fed state simulated intestinal fluid (FaSSIF and FeSSIF, respectively). A set of non-ionized poorly soluble compounds was studied in biorelevant media prepared from an instantly dissolving complex (SIF(™) Powder) at 37°C. The values of the solubilization capacity were different between FaSSIF and FeSSIF but correlated. Drug inclusion into the mixed micelles was highly specific for a given compound. The ratio of the FeSSIF to FaSSIF solubility was in particular considered and discussed in terms of the apparent solubilizing capacity. The apparent solubilization concept appears to be useful for the interpretation of biorelevant solubility tests. Further studies are needed to explore acidic and basic drugs.

  8. Exploring the Arabidopsis proteome: influence of protein solubilization buffers on proteome coverage.

    PubMed

    Marondedze, Claudius; Wong, Aloysius; Groen, Arnoud; Serrano, Natalia; Jankovic, Boris; Lilley, Kathryn; Gehring, Christoph; Thomas, Ludivine

    2014-12-31

    The study of proteomes provides new insights into stimulus-specific responses of protein synthesis and turnover, and the role of post-translational modifications at the systems level. Due to the diverse chemical nature of proteins and shortcomings in the analytical techniques used in their study, only a partial display of the proteome is achieved in any study, and this holds particularly true for plant proteomes. Here we show that different solubilization and separation methods have profound effects on the resulting proteome. In particular, we observed that the type of detergents employed in the solubilization buffer preferentially enriches proteins in different functional categories. These include proteins with a role in signaling, transport, response to temperature stimuli and metabolism. This data may offer a functional bias on comparative analysis studies. In order to obtain a broader coverage, we propose a two-step solubilization protocol with first a detergent-free buffer and then a second step utilizing a combination of two detergents to solubilize proteins.

  9. A class-A GPCR solubilized under high hydrostatic pressure retains its ligand binding ability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of high hydrostatic pressure (HHP) on the solubilization of a class-A G protein-coupled receptor, the silkmoth pheromone biosynthesis-activating neuropeptide receptor (PBANR), was investigated. PBANR was expressed in expresSF+ insect cells as a C-terminal fusion protein with EGFP. The mem...

  10. Sub-CMC solubilization of dodecane by rhamnolipid in saturated porous media

    PubMed Central

    Zhong, Hua; Zhang, Hui; Liu, Zhifeng; Yang, Xin; Brusseau, Mark L.; Zeng, Guangming

    2016-01-01

    Experiments were conducted with a two-dimensional flow cell to examine the effect of monorhamnolipid surfactant at sub-CMC concentrations on solubilization of dodecane in porous media under dynamic flow conditions. Quartz sand was used as the porous medium and artificial groundwater was used as the background solution. The effectiveness of the monorhamnolipid was compared to that of SDBS, Triton X-100, and ethanol. The results demonstrated the enhancement of dodecane solubility by monorhamnolipid surfactant at concentrations lower than CMC. The concentrations (50–210 μM) are sufficiently low that they do not cause mobilization of the dodecane. Retention of rhamnolipid in the porous medium and detection of nano-size aggregates in the effluent show that the solubilization is based on a sub-CMC aggregate-formation mechanism, which is significantly stronger than the solubilization caused by the co-solvent effect. The rhamnolipid biosurfactant is more efficient for the solubilization compared to the synthetic surfactants. These results indicate a strategy of employing low concentrations of rhamnolipid for surfactant-enhanced aquifer remediation (SEAR), which may overcome the drawbacks of using surfactants at hyper-CMC concentrations. PMID:27619361

  11. Cytotoxic and anti-angiogenic paclitaxel solubilized and permeation-enhanced by natural product nanoparticles

    PubMed Central

    Liu, Zhijun; Zhang, Fang; Koh, Gar Yee; Dong, Xin; Hollingsworth, Javoris; Zhang, Jian; Russo, Paul S.; Yang, Peiying; Stout, Rhett W.

    2014-01-01

    Paclitaxel (PTX) is one of the most potent intravenous chemotherapeutic agents to date, yet an oral formulation has been problematic due to its low solubility and permeability. Using the recently discovered solubilizing properties of rubusoside (RUB), we investigated this unique PTX-RUB formulation. Paclitaxel was solubilized by RUB in water to levels of 1.6 to 6.3 mg/mL at 10 to 40% weight/volume. These, nanomicellar, PTX-RUB complexes were dried to a powder which was subsequently reconstituted in physiologic solutions. After 2.5 hrs in gastric fluid 85 to 99% of PTX-RUB remained soluble, while 79 to 96% remained soluble in intestinal fluid. The solubilization of PTX was mechanized by the formation of water-soluble spherical nanomicelles between PTX and RUB with an average diameter of 6.6 nm. Compared with Taxol®, PTX-RUB nanoparticles were nearly four times more permeable in Caco-2 cell monocultures. In a side-by-side comparison with DMSO-solubilized PTX, PTX-RUB maintained the same level of cytotoxicity against three human cancer cell lines with IC50 values ranging from 4 nM to 20 nM. Additionally, tubular formation and migration of HUVECs were inhibited at levels as low as 5 nM. These chemical and biological properties demonstrated by the PTX-RUB nanoparticles may improve oral bioavailability and enable further pharmacokinetic, toxicologic, and efficacy investigations. PMID:25243454

  12. Functional reconstitution of the bovine brain GABA sub A receptor from solubilized components

    SciTech Connect

    Dunn, S.M.J.; Martin, C.R.; Agey, M.W.; Miyazaki, R. )

    1989-03-21

    The GABA{sub A}/benzodiazepine receptor has been solubilized from membrane preparations of bovine cerebral cortex and has been reconstituted, in a functionally active form, into phospholipid vesicles. In preliminary experiments, the receptor was labeled with the photoactive benzodiazepine ({sup 3}H)flunitrazepam prior to solubilization. A peptide of apparent molecular weight 53,500 was specifically labeled by this method, and this was used as a marker for the receptor during the reconstitution procedures. The labeled protein was solubilized with approximately 40% efficiency by 1% {beta}-octyl glucoside. Reconstitution was achieved by mixing the solubilized proteins with a 4:1 mixture of soybean asolectin and bovine brain phospholipids, followed by chromatography on Sephadex G-50-80 to remove detergent. The incorporation of the GABA{sub A} receptor into membrane vesicles has been verified by sucrose gradient centrifugation in which the ({sup 3}H)-flunitrazepam-labeled peptide comigrated with ({sup 14}C)phosphatidylcholine used as a lipid marker. Vesicles prepared without labeled markers retained the ability to bind both ({sup 3}H)flunitrazepam and the GABA analogue ({sup 3}H)muscimol. A novel fluorescence technique has been used to measure chloride transport mediated by the GABA{sub A} receptor in reconstituted vesicles. Flux was also blocked by pretreatment with the competitive GABA{sub A} receptor blocker bicuculline or with the noncompetitive GABA{sub A} receptor antagonist picrotoxin.

  13. SURFACTANT-ENHANCED SOLUBILIZATION OF RESIDUAL DODECANE IN SOIL COLUMNS - 2. MATHEMATICAL MODELING

    EPA Science Inventory

    A mathematical model is developed to describe surfactant-enhanced solubilization of nonaqueous-phase liquids (NAPLs) in porous media. The model incorporates aqueous-phase transport equations for organic and surfactant components as well as a mass balance for the organic phase. Ra...

  14. Enhancement of clover growth by inoculation of P-solubilizing fungi and arbuscular mycorrhizal fungi.

    PubMed

    Souchie, Edson L; Azcón, Rosario; Barea, Jose M; Silva, Eliane M R; Saggin-Júnior, Orivaldo J

    2010-09-01

    This study evaluated the synergism between several P-solubilizing fungi isolates and arbuscular mycorrhizal fungi to improve clover ( Trifolium pratense) growth in the presence of Araxá apatite. Clover was sown directly in plastic pots with 300g of sterilized washed sand, vermiculite and sepiolite 1:1:1 (v:v:v) as substrate, and grown in a controlled environment chamber. The substrate was fertilized with 3 g L(-1) of Araxá apatite. A completely randomized design, in 8×2 factorial scheme (eight P-solubilizing fungi treatments with or without arbuscular mycorrhizal fungi)and four replicates were used. The P-solubilizing fungi treatments consisted of five Brazilian P-solubilizing fungi isolates (PSF 7, 9, 20, 21 and 22), two Spanish isolates ( Aspergillus niger and the yeast Yarowia lipolytica) and control (non-inoculated treatment). The greatest clover growth rate was recorded when Aspergillus niger and PSF 21 were co-inoculated with arbuscular mycorrhizal fungi. Aspergillus niger, PSF 7 and PSF 21 were the most effective isolates on increasing clover growth in the presence of arbuscular mycorrhizal fungi. Greater mycorrhizal colonization resulted in greater clover growth rate in most PSF treatments. PSF 7 was the best isolate to improve the establishment of mycorrhizal and rhizobia symbiosis.

  15. Structural analysis of bacteriorhodopsin solubilized by lipid-like phosphocholine biosurfactants with varying micelle concentrations.

    PubMed

    Wang, Xiaoqiang; Huang, Haihong; Sun, Chenghao; Huang, Fang

    2015-01-01

    Surfactants that can provide a more natural substitute for lipid bilayers are important in the purification and in vitro study of membrane proteins. Here we investigate the structural response of a model membrane protein, bacteriorhodopsin (BR), to phosphocholine biosurfactants. Phosphocholine biosurfactants are a type of biomimetic amphiphile that are similar to phospholipids, in which membrane proteins are commonly embedded. Multiple spectroscopic and zeta potential measurements are employed to characterize the conformational change, secondary and tertiary structure, oligomeric status, surface charge distribution and the structural stability of BR solubilized with phosphocholine biosurfactants of varying tail length. The process of phosphocholine micelle formation is found to facilitate the solubilization of BR, and for long-chain phosphocholines, concentrations much higher than their critical micelle concentrations achieve good solubilization. Phosphocholine biosurfactants are shown to be mild compared with the ionic surfactant SDS or CTAB, and tend to preserve membrane protein structure during solubilization, especially at low micelle concentrations, by virtue of their phospholipid-like zwitterionic head groups. The increase of alkyl chain length is shown to obviously enhance the capability of phosphocholine biosurfactants to stabilize BR. The underlying mechanism for the favorable actions of phosphocholine biosurfactant is also discussed.

  16. Applying solubilization treatment to reverse clogging in laboratory-scale vertical flow constructed wetlands.

    PubMed

    Guofen, Hua; Wei, Zhu; Lianfang, Zhao; Yunhui, Zhang

    2010-01-01

    Substrate clogging is characterized as a frequently occurring operational problem for subsurface-flow constructed wetlands. The application of solubilization treatment to reduce clogging was tested in lab-scaled setups to provide a promising solution. The performance of solubilization treatment on reducing clogging and the related effects on plants and biofilms in the wetland system were investigated in this paper. The results showed that the infiltration rate and available porosity of wetland substrate increased as a function of increased dosage of NaOH, HCl, NaClO, and detergent, respectively. Among the four solvents, it appeared that NaClO had the most obvious effects on reducing clogging and the infiltration rate and effective porosity recovered to 69% of the original condition. The two possible reasons for solubilization were the flocculents' structure of the clogs was broken up or parts of the organic clogs were dissolved. The function of adding NaOH and NaClO was to dissolve the protein and polysaccharides of the organic clogs; the function of adding HCl was to release the anaerobic gas wrapped in the organic clogs. Furthermore, experiments results also showed that the solubilized solvents did not demonstrate a long-term negative effect on plants and biofilms.

  17. Isolation and characterization of Chilembwe and Sinda Rock Phosphate solubilizing soil microorganisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was conducted to isolate and characterize soil microorganisms capable of solubilizing Chilembwe and Sinda rock phosphates readily available in Zambia. Single isolates were obtained by direct plating and enrichment cultures with succinate, cellulose and glucose as the carbon sources. Isola...

  18. Cytotoxic and antiangiogenic paclitaxel solubilized and permeation-enhanced by natural product nanoparticles.

    PubMed

    Liu, Zhijun; Zhang, Fang; Koh, Gar Yee; Dong, Xin; Hollingsworth, Javoris; Zhang, Jian; Russo, Paul S; Yang, Peiying; Stout, Rhett W

    2015-02-01

    Paclitaxel (PTX) is one of the most potent intravenous chemotherapeutic agents to date, yet an oral formulation has been problematic because of its low solubility and permeability. Using the recently discovered solubilizing properties of rubusoside (RUB), we investigated the unique PTX-RUB formulation. PTX was solubilized by RUB in water to levels of 1.6-6.3 mg/ml at 10-40% weight/volume. These nanomicellar PTX-RUB complexes were dried to a powder, which was subsequently reconstituted in physiologic solutions. After 2.5 h, 85-99% of PTX-RUB remained soluble in gastric fluid, whereas 79-96% remained soluble in intestinal fluid. The solubilization of PTX was mechanized by the formation of water-soluble spherical nanomicelles between PTX and RUB, with an average diameter of 6.6 nm. Compared with Taxol, PTX-RUB nanoparticles were nearly four times more permeable in Caco-2 cell monocultures. In a side-by-side comparison with dimethyl sulfoxide-solubilized PTX, PTX-RUB maintained the same level of cytotoxicity against three human cancer cell lines with IC50 values ranging from 4 to 20 nmol/l. In addition, tubule formation and migration of human umbilical vein endothelial cells were inhibited at levels as low as 5 nmol/l. These chemical and biological properties demonstrated by the PTX-RUB nanoparticles may improve oral bioavailability and enable further pharmacokinetic, toxicologic, and efficacy investigations.

  19. FIELD DEMONSTRATION STUDIES OF SURFACTANT-ENHANCED SOLUBILIZATION AND MOBILIZATION AT HILL AIR FORCE BASE, UTAH

    EPA Science Inventory

    Surfactant-enhanced subsurface remediation can dramatically improve contaminant removal rates compared to the traditional pump-and-treat technology. Surfactants can be used to significantly enhance the solubilization of non-aqueous phase liquids (NAPL) constituents, or they can b...

  20. Solubilization of Mixed Non-aqueous Phase Liquids (NAPLs) by Tween-80

    NASA Astrophysics Data System (ADS)

    Kang, S.; Jeong, H. Y.

    2011-12-01

    Groundwater contamination by organic pollutants is a widespread problem. Due to the low water solubility of many organic pollutants, conventional pump-and-treat technology has had little success in the remediation of contaminated groundwater. Thus, surfactant- enhanced aquifer remediation (SEAR) is under investigation to enhance the performance of conventional pump-and-treat technologies. Surfactants have the ability to increase apparent aqueous solubility of many insoluble organic compounds. To date, most SEAR works have been focused on the examination of the pure non-aqueous phase liquid (NAPL)-contaminated sites. However, a discharge into groundwater is usually not composed of a single component, but rather a mixture of several NAPLs. In this study, ternary mixtures of organic compounds with a range of hydrophobicity were investigated to assess the micellar solubilization behavior of each component in mixed NAPLs using Tween-80, a non-ionic surfactant. The experimental results reveal that the micellar solubilization behavior in the mixed NAPLS differs significantly from that in the corresponding single component systems. Compared with the pure NAPLs, less hydrophobic constituents in the mixed NAPLs show the decreased solubilization, while more hydrophobic components exhibit the elevated solubilization. Acknowledgement: This subject is supported by Korea Ministry of Environment as "The GAIA Project No. 173-092-011."

  1. [Solubilization of nitrobenzene in micellar solutions of Tween 80 and inorganic salts].

    PubMed

    Li, Sui; Zhao, Yong-sheng; Xu, Wei; Dai, Ning

    2008-04-01

    The solubilization of nitrobenzene by a nonionic surfactant Tween 80 was investigated at 10 degrees C. Experimental results indicated that the solubility of nitrobenzene in water was greatly enhanced by Tween 80 at surfactant concentration above CMC(critical micelle concentration) and a linear relationship was obtained between surfactant concentration and nitrobenzene concentration from the solubility curve. The molar solubilization ratio (MSR) value was 5.093 and IgKm was 3.499. The solubilization was attributed to the ethoxylation group in Tween 80 micellar. Effect of four inorganic salts such as NaCl, KCl, CaCl2 , MgCl2 on water solubilities of nitrobenzene in Tween 80 micellar solutions was also investigated by a matrix of batch experiments. Mix the Tween 80-inorganic salts at the total mass ratios of 2:1, 5:1 and 10:1. The results show that the inorganic salts at a high concentration( > or = 500 mg x L(-1)) can enhance the solubilization capacities of Tween 80 micellar solution and increase the value of MSR and IgKm . Because of the salting-out effect between the micellar of Tween 80 and inorganic salts, the volume of micelle turns bigger, which may provide larger solubility volume for nitrobenzene. The mixture of nonionic surfactant and inorganic salts can be used in subsurface remediation as a flushing solution.

  2. Characterization of (/sup 3/H)pirenzepine binding to muscarinic cholinergic receptors solubilized from rat brain

    SciTech Connect

    Luthin, G.R.; Wolfe, B.B.

    1985-07-01

    Membranes prepared from rat cerebral cortex were solubilized in buffer containing 1% digitonin. Material present in the supernatant after centrifugation at 147,000 X g was shown to contain binding sites for both (/sup 3/H)quinuclidinyl benzilate ((/sup 3/H)QNB) and (/sup 3/H)pirenzepine ((/sup 3/H)PZ). Recovery of binding sites was approximately 25% of the initial membrane-bound (/sup 3/H)QNB binding sites. The Kd values for (/sup 3/H)QNB and (/sup 3/H)PZ binding to solubilized receptors were 0.3 nM and 0.1 microM, respectively. As has been observed previously in membrane preparations, (/sup 3/H)PZ appeared to label fewer solubilized binding sites than did (/sup 3/H)QNB. Maximum binding values for (/sup 3/H)PZ and (/sup 3/H)QNB binding to solubilized receptors were approximately 400 and 950 fmol/mg of protein, respectively. Competition curves for PZ inhibiting the binding of (/sup 3/H)QNB, however, had Hill slopes of 1, with a Ki value of 0.24 microM. The k1 and k-1 for (/sup 3/H)PZ binding were 3.5 X 10(6) M-1 min-1 and 0.13 min-1, respectively. The muscarinic receptor antagonists atropine, scopolamine and PZ inhibited the binding of (/sup 3/H)QNB and (/sup 3/H)PZ to solubilized receptors with Hill slopes of 1, as did the muscarinic receptor agonist oxotremorine. The muscarinic receptor agonist carbachol competed for (/sup 3/H)QNB and (/sup 3/H)PZ binding with a Hill slope of less than 1 in cerebral cortex, but not in cerebellum. GTP did not alter the interactions of carbachol or oxotremorine with the solubilized receptor. Together, these data suggest that muscarinic receptor sites solubilized from rat brain retain their abilities to interact selectively with muscarinic receptor agonists and antagonists.

  3. Solubilization and stabilization of isolated photosystem I complex with lipopeptide detergents.

    PubMed

    Wang, Xiaoqiang; Huang, Guihong; Yu, Daoyong; Ge, Baosheng; Wang, Jiqian; Xu, Fengxi; Huang, Fang; Xu, Hai; Lu, Jian R

    2013-01-01

    It is difficult to maintain a target membrane protein in a soluble and functional form in aqueous solution without biological membranes. Use of surfactants can improve solubility, but it remains challenging to identify adequate surfactants that can improve solubility without damaging their native structures and biological functions. Here we report the use of a new class of lipopeptides to solubilize photosystem I (PS-I), a well known membrane protein complex. Changes in the molecular structure of these surfactants affected their amphiphilicity and the goal of this work was to exploit a delicate balance between detergency and biomimetic performance in PS-I solubilization via their binding capacity. Meanwhile, the effects of these surfactants on the thermal and structural stability and functionality of PS-I in aqueous solution were investigated by circular dichroism, fluorescence spectroscopy, SDS-PAGE analysis and O2 uptake measurements, respectively. Our studies showed that the solubility of PS-I depended on both the polarity and charge in the hydrophilic head of the lipopeptides and the length of its hydrophobic tail. The best performing lipopeptides in favour of PS-I solubility turned out to be C14DK and C16DK, which were comparable to the optimal amphiphilicity of the conventional chemical surfactants tested. Lipopeptides showed obvious advantages in enhancing PS-I thermostability over sugar surfactant DDM and some full peptide amphiphiles reported previously. Fluorescence spectroscopy along with SDS-PAGE analysis demonstrated that lipopeptides did not undermine the polypeptide composition and conformation of PS-I after solubilization; instead they showed better performance in improving the structural stability and integrity of this multi-subunit membrane protein than conventional detergents. Furthermore, O2 uptake measurements indicated that PS-I solubilized with lipopeptides maintained its functionality. The underlying mechanism for the favorable actions of

  4. Comparison in toxicity and solubilizing capacity of hydroxypropyl-β-cyclodextrin with different degree of substitution.

    PubMed

    Li, Pengyu; Song, Jia; Ni, Xiaomin; Guo, Qin; Wen, Hui; Zhou, Qiuyun; Shen, Yuanna; Huang, Yijun; Qiu, Pengxin; Lin, Suizhen; Hu, Haiyan

    2016-11-20

    Hydroxypropyl-β-cyclodextrin (HP-β-CD) has been widely used as an effective solubilizing agent in pharmaceutical industry for many years. However, the effect of degree of substitution (D.S.) of HP-β-CD on solubilizing capacity and toxicity has not been concerned. In this study, solubilizing capacity of HP-β-CDs with three different D.S. (4.55, 6.16 and 7.76) for 16 drugs were measured and their toxicities were compared by a 7-day i.v. administration (q.d.) study in rats. Generally, HP-β-CD with high D.S. (7.76) showed weaker solubilizing capacity for steroids and BCS class II drugs, but lower hemolytic activity, compared with that of HP-β-CD with low (4.55) or medium (6.16) D.S. HP-β-CD with low D.S. resulted in more changes in hematological and biochemical parameters, but the effects were reversible after a 7-day recovery. Moreover, HP-β-CD with medium D.S. may have slightly greater nephrotoxicity than the other two HP-β-CDs. HP-β-CDs with different D.S. had similar urine excretion percentage after i.v. administration and none of them was found to affect glomerular filtration function of rats. The results suggest that HP-β-CD with low D.S. would be a better choice considering both the solubilizing capacity and toxicity. However, comparison in toxicity of HP-β-CDs with different D.S. should be carried out in human in view of its species-dependence property.

  5. Microbial Metalloproteomics

    PubMed Central

    Hagedoorn, Peter-Leon

    2015-01-01

    Metalloproteomics is a rapidly developing field of science that involves the comprehensive analysis of all metal-containing or metal-binding proteins in a biological sample. The purpose of this review is to offer a comprehensive overview of the research involving approaches that can be categorized as inductively coupled plasma (ICP)-MS based methods, X-ray absorption/fluorescence, radionuclide based methods and bioinformatics. Important discoveries in microbial proteomics will be reviewed, as well as the outlook to new emerging approaches and research areas. PMID:28248278

  6. Microbial Metabolomics

    PubMed Central

    Tang, Jane

    2011-01-01

    Microbial metabolomics constitutes an integrated component of systems biology. By studying the complete set of metabolites within a microorganism and monitoring the global outcome of interactions between its development processes and the environment, metabolomics can potentially provide a more accurate snap shot of the actual physiological state of the cell. Recent advancement of technologies and post-genomic developments enable the study and analysis of metabolome. This unique contribution resulted in many scientific disciplines incorporating metabolomics as one of their “omics” platforms. This review focuses on metabolomics in microorganisms and utilizes selected topics to illustrate its impact on the understanding of systems microbiology. PMID:22379393

  7. The role of mycorrhizae and plant growth promoting rhizobacteria (PGPR) in improving crop productivity under stressful environments.

    PubMed

    Nadeem, Sajid Mahmood; Ahmad, Maqshoof; Zahir, Zahir Ahmad; Javaid, Arshad; Ashraf, Muhammad

    2014-01-01

    Both biotic and abiotic stresses are major constrains to agricultural production. Under stress conditions, plant growth is affected by a number of factors such as hormonal and nutritional imbalance, ion toxicity, physiological disorders, susceptibility to diseases, etc. Plant growth under stress conditions may be enhanced by the application of microbial inoculation including plant growth promoting rhizobacteria (PGPR) and mycorrhizal fungi. These microbes can promote plant growth by regulating nutritional and hormonal balance, producing plant growth regulators, solubilizing nutrients and inducing resistance against plant pathogens. In addition to their interactions with plants, these microbes also show synergistic as well as antagonistic interactions with other microbes in the soil environment. These interactions may be vital for sustainable agriculture because they mainly depend on biological processes rather than on agrochemicals to maintain plant growth and development as well as proper soil health under stress conditions. A number of research articles can be deciphered from the literature, which shows the role of rhizobacteria and mycorrhizae alone and/or in combination in enhancing plant growth under stress conditions. However, in contrast, a few review papers are available which discuss the synergistic interactions between rhizobacteria and mycorrhizae for enhancing plant growth under normal (non-stress) or stressful environments. Biological interactions between PGPR and mycorrhizal fungi are believed to cause a cumulative effect on all rhizosphere components, and these interactions are also affected by environmental factors such as soil type, nutrition, moisture and temperature. The present review comprehensively discusses recent developments on the effectiveness of PGPR and mycorrhizal fungi for enhancing plant growth under stressful environments. The key mechanisms involved in plant stress tolerance and the effectiveness of microbial inoculation for

  8. Effect of an arbuscular mycorrhizal fungus, Glomus mosseae, and a rock-phosphate-solubilizing fungus, Penicillium thomii, on Mentha piperita growth in a soilless medium.

    PubMed

    Cabello, Marta; Irrazabal, Gabriela; Bucsinszky, Ana Maria; Saparrat, Mario; Schalamuk, Santiago

    2005-01-01

    Rock phosphate effect on English mint (Mentha piperita L.) grown on steamed perlite:vermiculite (1:1, v:v) substrate, with and without rock phosphate, was evaluated in greenhouse experiments. Five treatments were carried out by inoculation with an arbuscular mycorrhizal fungus Glomus mosseae and a phosphorus solubilizing microorganism Penicillium thomii. Plant aerial biomass, phosphorus concentration in plant tissue, and P available in the substrate, were evaluated upon two harvests. After the first harvest, plant aerial biomass did not show significant differences between treatments using rock phosphate as fertilizer, although P content in plants inoculated with P. thomii was higher. The second harvest revealed a higher biomass and plant tissue P content in treatments inoculated with G. mosseae. P. thomii increased P available in the substrate, whereas in the absence of G. mosseae, it did not enhance plant tissue P content. Mycorrhizal colonization was not affected by P. thomii. Microbial inoculation effect on English mint growth was also evaluated. The microbial effect was positive in all treatments when compared with the control without rock phosphate.

  9. Effective detergent/chlorophyll ratio and detergent concentration in the aqueous phase during solubilization of Phormidium laminosum membranes.

    PubMed

    Ochoa de Alda, J A; Llama, M J; Serra, J L

    1995-12-13

    Experiments of turbidity decrease induced by detergents were systematically performed to characterize the solubilization of Phormidium laminosum membrane fragments. SDS, Triton X-100 and a mixture of octyl glucoside/decyl maltoside/lithium dodecyl sulfate (OG/DM/LiDS, in a molar ratio of 4.19:2.54:1) were used. The detergent concentration in the aqueous phase (DW) and the effective detergent/chlorophyll ratio in mixed aggregates (Re) were determined. Both parameters increased during the solubilization and in an exponential way in the range from 10 to 90% solubilization. At detergent concentrations which caused the complete solubilization, Dw values were close to the described critical micellar concentrations (cmc), but solubilization started at concentrations well below the cmc. At the onset of solubilization five molecules of SDS, one of Triton X-100 and three of the mixture OG/DM/LiDS, per chlorophyll molecule, saturated the membrane fragments. The increase of Dw and Re values was characterized by two constants. This permits the design of a model to predict the detergent concentration which produces a desired solubilization of thylakoid membrane fragments for a given chlorophyll concentration.

  10. Impact of thermo-chemo-sonic pretreatment in solubilizing waste activated sludge for biogas production: Energetic analysis and economic assessment.

    PubMed

    Kavitha, S; Rajesh Banu, J; Subitha, G; Ushani, U; Yeom, Ick Tae

    2016-11-01

    The objective of this study was to determine the impact of solubilization during thermo-chemo-sonic pretreatment of waste activated sludge (WAS) on anaerobic biodegradability and cost for biogas production. The results revealed that it was possible to achieve 40-50% of solubilization of WAS when ultrasonic energy input was doubled (11,520-27,000kJ/kgTS). The cost to achieve 30-35% of solubilization of WAS was calculated to be 0.22-0.24USD/L, which was relatively lower than the cost of 0.53-0.8USD/L when 40-50% of solubilisation of WAS was achieved. There was no significant difference in biodegradability (0.60-0.64gCOD/gCOD) for samples with solubilization efficiency of 35-50%. Comparing energetic balance and economic assessment of samples with different solubilization percentages, the results showed that samples with 30-35% of solubilization had lower net cost (7.98-2.33USD/Ton of sludge) and negative energy balance compared to samples with other percentages of solubilization.

  11. Plant growth promoting properties of Halobacillus sp. and Halomonas sp. in presence of salinity and heavy metals.

    PubMed

    Desale, Prithviraj; Patel, Bhargav; Singh, Sukrit; Malhotra, Aakshi; Nawani, Neelu

    2014-08-01

    Salinity and heavy metal stress are challenging problems in agriculture. Here we report the plant growth promoting ability of three moderate halophiles, Halobacillus sp. ADN1, Halomonas sp. MAN5, and Halobacillus sp. MAN6, in presence of both salinity and heavy metal stress. Halobacillus sp. ADN1, Halomonas sp. MAN5, and Halobacillus sp. MAN6 can tolerate 25, 21, and 29% NaCl, respectively and grow in presence of 1 mM cobalt, cadmium, and nickel and 0.04 mM mercury and 0.03 mM silver. Halobacillus sp. ADN1, Halomonas sp. MAN5, and Halobacillus sp. MAN6 produced 152.5, 95.3, and 167.3 µg/ml indole acetic acid (IAA) and could solubilize 61, 53, and 75 parts per million (ppm) phosphate, respectively in the presence of 15% NaCl. The production of IAA and solubilization of phosphate was well retained in the presence of salinity and heavy metals like 1 mM cadmium, 0.7 mM nickel, 0.04 mM mercury, and 0.03 mM silver. Besides, the strains showed amylase and protease activities and could produce hydrogen cyanide and ammonia in presence of salinity and heavy metals. A mixture of three strains enhanced the root growth of Sesuvium portulacastrum under saline and heavy metal stress, where the root length increased nearly 4.5 ± 0.6 times and root dry weight increased 5.4 ± 0.5 times as compared to control. These strains can thus be useful in microbial assisted phytoremediation of polluted saline soils.

  12. A Complex Inoculant of N2-Fixing, P- and K-Solubilizing Bacteria from a Purple Soil Improves the Growth of Kiwifruit (Actinidia chinensis) Plantlets

    PubMed Central

    Shen, Hong; He, Xinhua; Liu, Yiqing; Chen, Yi; Tang, Jianming; Guo, Tao

    2016-01-01

    Limited information is available if plant growth promoting bacteria (PGPB) can promote the growth of fruit crops through improvements in soil fertility. This study aimed to evaluate the capacity of PGPB, identified by phenotypic and 16S rRNA sequencing from a vegetable purple soil in Chongqing, China, to increase soil nitrogen (N), phosphorus (P), and potassium (K) availability and growth of kiwifruit (Actinidia chinensis). In doing so, three out of 17 bacterial isolates with a high capacity of N2-fixation (Bacillus amyloliquefaciens, XD-N-3), P-solubilization (B. pumilus, XD-P-1) or K-solubilization (B. circulans, XD-K-2) were mixed as a complex bacterial inoculant. A pot experiment then examined its effects of this complex inoculant on soil microflora, soil N2-fixation, P- and K-solubility and kiwifruit growth under four treatments. These treatments were (1) no-fertilizer and no-bacterial inoculant (Control), (2) no-bacterial inoculant and a full-rate of chemical NPK fertilizer (CF), (3) the complex inoculant (CI), and (4) a half-rate CF and full CI (1/2CF+CI). Results indicated that significantly greater growth of N2-fixing, P- and K-solubilizing bacteria among treatments ranked from greatest to least as under 1/2CF+CI ≈ CI > CF ≈ Control. Though generally without significant treatment differences in soil total N, P, or K, significantly greater soil available N, P, or K among treatments was, respectively, patterned as under 1/2CF+CI ≈ CI > CF ≈ Control, under 1/2CF+CI > CF > CI > Control or under 1/2CF+CI > CF ≈ CI > Control, indicating an improvement of soil fertility by this complex inoculant. In regards to plant growth, significantly greater total plant biomass and total N, P, and K accumulation among treatments were ranked as 1/2CF+CI ≈ CI > CF > Control. Additionally, significantly greater leaf polyphenol oxidase activity ranked as under CF > 1/2CF+CI ≈ Control ≈ CI, while leaf malondialdehyde contents as under Control > CI ≈ CF > 1/2CF

  13. A Complex Inoculant of N2-Fixing, P- and K-Solubilizing Bacteria from a Purple Soil Improves the Growth of Kiwifruit (Actinidia chinensis) Plantlets.

    PubMed

    Shen, Hong; He, Xinhua; Liu, Yiqing; Chen, Yi; Tang, Jianming; Guo, Tao

    2016-01-01

    Limited information is available if plant growth promoting bacteria (PGPB) can promote the growth of fruit crops through improvements in soil fertility. This study aimed to evaluate the capacity of PGPB, identified by phenotypic and 16S rRNA sequencing from a vegetable purple soil in Chongqing, China, to increase soil nitrogen (N), phosphorus (P), and potassium (K) availability and growth of kiwifruit (Actinidia chinensis). In doing so, three out of 17 bacterial isolates with a high capacity of N2-fixation (Bacillus amyloliquefaciens, XD-N-3), P-solubilization (B. pumilus, XD-P-1) or K-solubilization (B. circulans, XD-K-2) were mixed as a complex bacterial inoculant. A pot experiment then examined its effects of this complex inoculant on soil microflora, soil N2-fixation, P- and K-solubility and kiwifruit growth under four treatments. These treatments were (1) no-fertilizer and no-bacterial inoculant (Control), (2) no-bacterial inoculant and a full-rate of chemical NPK fertilizer (CF), (3) the complex inoculant (CI), and (4) a half-rate CF and full CI (1/2CF+CI). Results indicated that significantly greater growth of N2-fixing, P- and K-solubilizing bacteria among treatments ranked from greatest to least as under 1/2CF+CI ≈ CI > CF ≈ Control. Though generally without significant treatment differences in soil total N, P, or K, significantly greater soil available N, P, or K among treatments was, respectively, patterned as under 1/2CF+CI ≈ CI > CF ≈ Control, under 1/2CF+CI > CF > CI > Control or under 1/2CF+CI > CF ≈ CI > Control, indicating an improvement of soil fertility by this complex inoculant. In regards to plant growth, significantly greater total plant biomass and total N, P, and K accumulation among treatments were ranked as 1/2CF+CI ≈ CI > CF > Control. Additionally, significantly greater leaf polyphenol oxidase activity ranked as under CF > 1/2CF+CI ≈ Control ≈ CI, while leaf malondialdehyde contents as under Control > CI ≈ CF > 1/2CF

  14. The effect of using citric or acetic acid on survival of Listeria monocytogenes during fish protein recovery by isoelectric solubilization and precipitation process.

    PubMed

    Otto, R A; Beamer, S; Jaczynski, J; Matak, K E

    2011-10-01

    Isoelectric solubilization and precipitation (ISP) is a protein recovery process effective at reducing Listeria innocua, a nonpathogenic bacterium typically used as a surrogate for L. monocytogenes in recovered trout protein. The response of L. monocytogenes to ISP processing was determined and compared to the response of L. innocua. Headed and gutted rainbow trout were inoculated with L. monocytogenes (10.16 log CFU/g), homogenized, and pH-adjusted with granular citric acid (pH 2.0 and 2.5) or glacial acetic acid (pH 3.0 and 3.5). Proteins were solubilized and centrifugation was used to remove insoluble components (skin, insoluble protein, so on). The supernatant was returned to the protein isoelectric point (pH 5.5) with NaOH and centrifuged to remove precipitated protein. Microbial load was enumerated on both growth and selective media; recovery was not significantly different (P > 0.05). Surviving cells from each component (protein, insoluble, and water) were compared to initial inoculum numbers. Significant reductions were detected at all pH (P < 0.05). The greatest reductions were at pH 3.0 with acetic acid, with a mean log reduction of 3.03 in the combined components, and a 3.53 log reduction in the protein portion. Data were compared to results from a previous study using L. innocua. Significant differences (P < 0.05) in recovery were found between the 2 species at pH 2.0 and 3.0 with greater recovery of L. monocytogenes, regardless of processing pH or acid type. These results demonstrate the variability in resistance between species and indicate that L. innocua is not an appropriate surrogate for L. monocytogenes for ISP processing with organic acids.

  15. Optimization of Aspergillus niger rock phosphate solubilization in solid-state fermentation and use of the resulting product as a P fertilizer

    PubMed Central

    Mendes, Gilberto de Oliveira; da Silva, Nina Morena Rêgo Muniz; Anastácio, Thalita Cardoso; Vassilev, Nikolay Bojkov; Ribeiro, José Ivo; da Silva, Ivo Ribeiro; Costa, Maurício Dutra

    2015-01-01

    A biotechnological strategy for the production of an alternative P fertilizer is described in this work. The fertilizer was produced through rock phosphate (RP) solubilization by Aspergillus niger in a solid-state fermentation (SSF) with sugarcane bagasse as substrate. SSF conditions were optimized by the surface response methodology after an initial screening of factors with significant effect on RP solubilization. The optimized levels of the factors were 865 mg of biochar, 250 mg of RP, 270 mg of sucrose and 6.2 ml of water per gram of bagasse. At this optimal setting, 8.6 mg of water-soluble P per gram of bagasse was achieved, representing an increase of 2.4 times over the non-optimized condition. The optimized SSF product was partially incinerated at 350°C (SB-350) and 500°C (SB-500) to reduce its volume and, consequently, increase P concentration. The post-processed formulations of the SSF product were evaluated in a soil–plant experiment. The formulations SB-350 and SB-500 increased the growth and P uptake of common bean plants (Phaseolus vulgaris L.) when compared with the non-treated RP. Furthermore, these two formulations had a yield relative to triple superphosphate of 60% (on a dry mass basis). Besides increasing P concentration, incineration improved the SSF product performance probably by decreasing microbial immobilization of nutrients during the decomposition of the remaining SSF substrate. The process proposed is a promising alternative for the management of P fertilization since it enables the utilization of low-solubility RPs and relies on the use of inexpensive materials. PMID:26112323

  16. Optimization of Aspergillus niger rock phosphate solubilization in solid-state fermentation and use of the resulting product as a P fertilizer.

    PubMed

    Mendes, Gilberto de Oliveira; da Silva, Nina Morena Rêgo Muniz; Anastácio, Thalita Cardoso; Vassilev, Nikolay Bojkov; Ribeiro, José Ivo; da Silva, Ivo Ribeiro; Costa, Maurício Dutra

    2015-11-01

    A biotechnological strategy for the production of an alternative P fertilizer is described in this work. The fertilizer was produced through rock phosphate (RP) solubilization by Aspergillus niger in a solid-state fermentation (SSF) with sugarcane bagasse as substrate. SSF conditions were optimized by the surface response methodology after an initial screening of factors with significant effect on RP solubilization. The optimized levels of the factors were 865 mg of biochar, 250 mg of RP, 270 mg of sucrose and 6.2 ml of water per gram of bagasse. At this optimal setting, 8.6 mg of water-soluble P per gram of bagasse was achieved, representing an increase of 2.4 times over the non-optimized condition. The optimized SSF product was partially incinerated at 350°C (SB-350) and 500°C (SB-500) to reduce its volume and, consequently, increase P concentration. The post-processed formulations of the SSF product were evaluated in a soil-plant experiment. The formulations SB-350 and SB-500 increased the growth and P uptake of common bean plants (Phaseolus vulgaris L.) when compared with the non-treated RP. Furthermore, these two formulations had a yield relative to triple superphosphate of 60% (on a dry mass basis). Besides increasing P concentration, incineration improved the SSF product performance probably by decreasing microbial immobilization of nutrients during the decomposition of the remaining SSF substrate. The process proposed is a promising alternative for the management of P fertilization since it enables the utilization of low-solubility RPs and relies on the use of inexpensive materials.

  17. Calcium Alginate and Calcium Alginate-Chitosan Beads Containing Celecoxib Solubilized in a Self-Emulsifying Phase

    PubMed Central

    Segale, Lorena; Giovannelli, Lorella; Mannina, Paolo; Pattarino, Franco

    2016-01-01

    In this work alginate and alginate-chitosan beads containing celecoxib solubilized into a self-emulsifying phase were developed in order to obtain a drug delivery system for oral administration, able to delay the drug release in acidic environment and to promote it in the intestinal compartment. The rationale of this work was linked to the desire to improve celecoxib therapeutic effectiveness reducing its gastric adverse effects and to favor its use in the prophylaxis of colon cancer and as adjuvant in the therapy of familial polyposis. The systems were prepared by ionotropic gelation using needles with different diameters (400 and 600 μm). Morphology, particle size, swelling behavior, and in vitro drug release performance of the beads in aqueous media with different pH were investigated. The experimental results demonstrated that the presence of chitosan in the formulation caused an increase of the mechanical resistance of the bead structure and, as a consequence, a limitation of the bead swelling ability and a decrease of the drug release rate at neutral pH. Alginate-chitosan beads could be a good tool to guarantee a celecoxib colon delivery. PMID:27127680

  18. Enhanced biodegradation of hydrocarbons in soil by microbial biosurfactant, sophorolipid.

    PubMed

    Kang, Seok-Whan; Kim, Young-Bum; Shin, Jae-Dong; Kim, Eun-Ki

    2010-03-01

    Effectiveness of a microbial biosurfactant, sophorolipid, was evaluated in washing and biodegradation of model hydrocarbons and crude oil in soil. Thirty percent of 2-methylnaphthalene was effectively washed and solubilized with 10 g/L of sophorolipid with similar or higher efficiency than that of commercial surfactants. Addition of sophorolipid in soil increased biodegradation of model compounds: 2-methylnaphthalene (95% degradation in 2 days), hexadecane (97%, 6 days), and pristane (85%, 6 days). Also, effective biodegradation method of crude oil in soil was observed by the addition of sophorolipid, resulting in 80% biodegradation of saturates and 72% aromatics in 8 weeks. These results showed the potentials of the microbial biosurfactant, sophorolipid, as an effective surfactant for soil washing and as an in situ biodegradation enhancer.

  19. Large scale solubilization of coal and bioconversion to utilizable energy. Quarterly technical progress report, January-March 1994

    SciTech Connect

    Mishra, N.C.

    1994-06-01

    In order to develop a system for large scale coal solubilization and its bioconversion to utilizable fuel, the authors plan to clone the genes encoding Neurospora protein that facilitate depolymerization of coal. They also plan to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms (Faison). In addition the product of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein.

  20. Large scale solubilization of coal and bioconversion to utilizable energy. Fifth quarterly technical report, January 1, 1995--March 31, 1995

    SciTech Connect

    Mishra, N.C.

    1995-12-01

    In order to develop a system for a large scale coal solubilization and its bioconversion to utilizable fuel, we plan to clone the genes encoding Neurospora protein that facilitate depolymerization of coal. We also plan to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms. In addition the product of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein.

  1. An Economic Framework of Microbial Trade

    PubMed Central

    Mee, Michael T.

    2015-01-01

    A large fraction of microbial life on earth exists in complex communities where metabolic exchange is vital. Microbes trade essential resources to promote their own growth in an analogous way to countries that exchange goods in modern economic markets. Inspired by these similarities, we developed a framework based on general equilibrium theory (GET) from economics to predict the population dynamics of trading microbial communities. Our biotic GET (BGET) model provides an a priori theory of the growth benefits of microbial trade, yielding several novel insights relevant to understanding microbial ecology and engineering synthetic communities. We find that the economic concept of comparative advantage is a necessary condition for mutualistic trade. Our model suggests that microbial communities can grow faster when species are unable to produce essential resources that are obtained through trade, thereby promoting metabolic specialization and increased intercellular exchange. Furthermore, we find that species engaged in trade exhibit a fundamental tradeoff between growth rate and relative population abundance, and that different environments that put greater pressure on group selection versus individual selection will promote varying strategies along this growth-abundance spectrum. We experimentally tested this tradeoff using a synthetic consortium of Escherichia coli cells and found the results match the predictions of the model. This framework provides a foundation to study natural and engineered microbial communities through a new lens based on economic theories developed over the past century. PMID:26222307

  2. Solubilization of Fe(III) oxide-bound trace metals by a dissimilatory Fe(III) reducing bacterium

    NASA Astrophysics Data System (ADS)

    Zachara, John M.; Fredrickson, Jim K.; Smith, Steven C.; Gassman, Paul L.

    2001-01-01

    Trace metals associate with Fe(III) oxides as adsorbed or coprecipitated species, and consequently, the biogeochemical cycles of iron and the trace metals are closely linked. This communication investigated the solubilization of coprecipitated Co(III) and Ni(II) from goethite (α-FeOOH) during dissimilatory bacterial iron reduction to provide insights on biogeochemical factors controlling trace-element fluxes in anoxic environments. Suspensions of homogeneously substituted Co-FeOOH (50 mmol/L as Co 0.01Fe 0.99OOH; 57Co-labeled) in eight different buffer/media solutions were inoculated with a facultative, metal-reducing bacteria isolated from groundwater ( Shewanella putrefacians CN32), and incubated under strictly anaerobic conditions for periods up to 32 days. Lactate (30 mmol/L) was provided as an electron donor. Growth and non-growth promoting conditions were established by adding or withholding PO 4 and/or trace metals ( 60Co-labeled) from the incubation media. Anthraquinone disulfonate (AQDS; 100 μmol/L) was added to most suspensions as an electron shuttle to enhance bacterial reduction. Solutions were buffered at circumneutral pH with either PIPES or bicarbonate buffers. Solid and liquid samples were analyzed at intermediate and final time points for aqueous and sorbed/precipitated (by HCl extraction) Fe(II) and Co(II). The bioreduced solids were analyzed by X-ray diffraction and field-emission electron microscopy at experiment termination. Ni-FeOOH (Ni 0.01Fe 0.99OOH) was used for comparison in select experiments. Up to 45% of the metal containing FeOOH was bioreduced; growth-supporting conditions did not enhance reduction. The biogenic Fe(II) strongly associated with the residual Fe(III) oxide as an undefined sorbed phase at low fractional reduction in PIPES buffer, and as siderite (FeCO 3) in bicarbonate buffer or as vivianite [Fe 3(PO 4) 2 · 8H 2O] when P was present. Cobalt(III) was reduced to Co(II) in proportion to its mole ratio in the solid. The

  3. Mechanistic insights into solubilization of rice protein isolates by freeze-milling combined with alkali pretreatment.

    PubMed

    Wang, Tao; Zhang, Hao; Wang, Li; Wang, Ren; Chen, Zhengxing

    2015-07-01

    The solubilization of rice protein isolates (RPIs) has been regarded as one of the critical and challenging processes affecting commercial availability. Simultaneous treatment with freezing and milling (freeze-milling) combined with alkali pretreatment can remarkably increase the maximum achievable amounts of soluble RPIs by up to 42 times. This study investigates the mechanism of solubilization of RPIs by freeze-milling (RPI(fm)). Structural analyses reveal that milling causes proteins to unfold with ice crystals formed inside protein bodies. Fluorescent and Fourier transform infrared spectra show that RPI(fm) possesses disrupted hydrophobic surface and exposed hydrophilic inner groups. Size exclusion chromatography results reveal that RPI(fm) exhibits disaggregation and strong water-protein interactions. These results indicate that freeze-milling may be a promising manufacturing technique in food industry.

  4. Molecular size and amino acid composition of H-2d antigen solubilized in Nonidet P-40.

    PubMed

    Rossowski, W; Kloczewiak, M; Radzikowski, C; Strzadala, L

    1976-01-01

    H-2d antigenic material solubilized by the detergent Nonidet P-40 from L-1210 mouse leukemia cells was isolated by gel filtration on Bio-Gel P-100. A single peak eluted in the void volume consisted of about 90% protein, 8% hexose and traces of sialic acids. In sedimentation velocity runs, the antigen sedimented as a single peak of 3-1 S. Molecular weight determined by sedimentation equilibrium as well as calculated from amino acid composition was found to be in the range of 53,000 daltons and approx. 45,000-51,000 when calculated from sodium dodecyl sulfate polyacrylamide gel electrophoresis. Secondary structure of H-2d glycoprotein was predicted from the amino acid composition. For NP-40-solubilized H-2d antigen, about 34% of helix, 13% beta sheet and 41% turns was found.

  5. Identification of the Cardiac Beta-Adrenergic Receptor Protein: Solubilization and Purification by Affinity Chromatography

    PubMed Central

    Lefkowitz, Robert J.; Haber, Edgar; O'Hara, Donald

    1972-01-01

    A protein that binds catecholamines with a specificity parallel to that of their in vivo effects on cardiac contractility (isoproterenol > epinephrine or norepinephrine > dopamine > dihydroxyphenylalanine) was solubilized from a microsomal fraction of canine ventricular myocardium. The binding protein was purified 500 to 800-fold by solubilization and subsequent affinity chromatography with conjugates of norepinephrine linked to agarose beads. Purified β-adrenergic binding protein exists in two forms, corresponding to molecular weights of 40,000 and 160,000. The purified material has a single association constant, 2.3 × 105 liters/mol (as compared to two association constants, 107 and 106 liters/mol, for the binding protein in particulate form) but retains the identical binding specificity for β-adrenergic drugs and antagonists. Images PMID:4507606

  6. Solubilization and renaturation of overexpressed aggregates of mutant tryptophan synthase alpha-subunits.

    PubMed Central

    Lim, W K; Smith-Somerville, H E; Hardman, J K

    1989-01-01

    Certain Escherichia coli tryptophan synthase mutant alpha-subunits encoded from mutagenized trpA-containing plasmids were overexpressed as insoluble aggregates which were seen as large, intracellular inclusion bodies. The insoluble aggregates were solubilized to various degrees by several neutral, chaotropic salts. The order of effectiveness of these salts (KSCN, NaI greater than NaNO3, LiBr greater than CaCl2) followed that for the Hofmeister series. Optimum conditions for the use of KSCN resulted in a maximum 70 to 75% solubilization of the aggregate forms for all mutant alpha-subunits examined. Removal of KSCN by dialysis resulted in the recovery of biological activity and of certain characteristic structural properties. Such salts may be a useful alternative for other recombinant protein aggregates which resist complete renaturation by commonly used treatments with guanidine or urea. Images PMID:2547334

  7. Alkali-solubilized organic matter from sludge and its degradability in the anaerobic process.

    PubMed

    Li, Dongzhe; Zhou, Yan; Tan, Youming; Pathak, Santosh; Majid, Maszenan Bin Abdul; Ng, Wun Jern

    2016-01-01

    This study investigates alkali-solubilized dissolved organic matter (DOM) and its fate in the anaerobic treatment process. DOM was fractionated into high molecular weight (HMW) protein-like substances (PL), HMW saccharide-like substances (SL), low molecular weight (LMW) PL, LMW SL, and humic acid-like substances (HAL). The results indicate alkali-solubilized DOM is primarily composed of LMW PL, HMW SL, and HAL. Alkaline pretreatment improved the overall anaerobic degradability of DOM in sludge (removal efficiency of total DOM increased by 28.4%). However, certain DOM fractions (mainly HMW PL and HAL) exhibited low degradability during anaerobic treatment, primarily caused by the low degradability of aromatic groups (such as aromatic amine groups from tryptophan-like PL). Alkaline pretreatment also resulted in an increase of residual DOM, which is mainly composed of HAL (52.9%) and HMW SL (49.9%).

  8. Influence of physical state of β-carotene (crystallized versus solubilized) on bioaccessibility.

    PubMed

    Xia, Ziyuan; McClements, David Julian; Xiao, Hang

    2015-01-28

    β-Carotene has potentially beneficial biological effects. However, its use is currently limited because of its low water-solubility, high melting point, and low oral bioavailability. This study investigated the influence of physical state (crystalline versus solubilized) on the bioaccessibility of β-carotene using a simulated gastrointestinal tract (GIT) model. Three delivery systems were compared: (1) β-carotene predissolved in a nanoemulsion; (2) β-carotene crystals mixed with a nanoemulsion; and (3) β-carotene crystals mixed with a phosphate-buffered saline (PBS). The changes in the microstructure of the delivery systems were characterized after each stage of the GIT model. The β-carotene bioaccessibility decreased in the order of delivery system 1 ≫ 2 > 3, which indicated that carotenoids solubilized within a oil phase were much more bioaccessible than those that formed crystals. This study provides important information for developing effective delivery systems for lipophilic bioactive components in food and beverage applications.

  9. Alkali and Acid Solubilization Effects on Rheological Properties of Horse Mackerel Muscle Proteins

    NASA Astrophysics Data System (ADS)

    Campo-Deaño, L.; Tovar, C. A.

    2008-07-01

    Influence of the acid (Type A) and alkali (Type B) solubilization of muscle proteins in the viscoelastic properties of surimi and surimi gels made from horse mackerel (Trachurus trachurus) muscle were evaluated. Stress and frequency sweep tests showed that surimi from method B presents higher viscoelastic moduli, lowest values of phase angle and minimum viscoelastic moduli dependence with frequency than surimi A. These results show a high inicial protein aggregation in surimi B, that could explain the greater firmness and hardness of this sample, showing a more compact network structure. From static and dynamic tests, gel developed from alkali solubilization resulted in higher gel strength and more rigid network than that from acidic pH, despite the incial protein aggregation of surimi B its protein keeps better gelation capacity. The less structural quality of GA gel is likely due to the more lipid content on the surimi as compared to alkali treatment.

  10. Plant growth promoting bacteria Enterobacter asburiae JAS5 and Enterobacter cloacae JAS7 in mineralization of endosulfan.

    PubMed

    Abraham, Jayanthi; Silambarasan, Sivagnanam

    2015-04-01

    Endosulfan and their metabolites can be detected in soils with a history of endosulfan application. Microbial degradation offers an effective approach to remove toxicants, and in this study, Enterobacter asburiae JAS5 and Enterobacter cloacae JAS7 were isolated through enrichment technique. The biodegradation of endosulfan and its metabolites rate constant (k) and DT50 were determined through first-order kinetic models. E. asburiae JAS5 degraded the endosulfan, and its metabolites in liquid medium was characterized by the k which was 0.382 day(-1) (α-endosulfan), 0.284 day(-1) (β-endosulfan) and 0.228 day(-1) (endosulfan sulphate), and DT50 was 1.8 day (α-endosulfan), 2.4 days (β-endosulfan) and 3.0 days (endosulfan sulphate). The α-endosulfan, β-endosulfan and endosulfan sulphate metabolites were present in the liquid medium that was degraded by E. cloacae JAS7 which was characterized by the k of 0.391, 0.297 day(-1) and 0.273 day(-1), and DT50 was 1.7, 2.3 and 2.5 days, respectively. The infrared spectrum of endosulfan degraded sample in the aqueous medium by E. asburiae JAS5 and E. cloacae JAS7 showed a band at 1402 cm(-1) which is the characteristics of COOH group. E. asburiae JAS5 and E. cloacae JAS7 strains also showed the ability of plant growth promoting traits such as indole-3-acetic acid (IAA) production, organic acids production and solubilization of various inorganic phosphates. E. asburiae JAS5 solubilized 324 ± 2 μg ml(-1) of tricalcium phosphate, 296 ± 6 μg ml(-1) of dicalcium phosphate and 248 ± 5 μg ml(-1) of zinc phosphate, whereas E. cloacae JAS7 solubilized 338 ± 5, 306 ± 4 and 268 ± 3 μg ml(-1) of tricalcium phosphate, dicalcium phosphate and zinc phosphate, respectively. The IAA production by JAS5 and JAS7 strains were estimated to be 38.6 ± 0.3 and 46.6 ± 0.5 μg ml(-1), respectively. These bacterial strains form a potential candidate for bioremediation of pesticide-contaminated agricultural

  11. Microbial siderophores and root exudates enhanced goethite dissolution and Fe/As uptake by As-hyperaccumulator Pteris vittata.

    PubMed

    Liu, Xue; Fu, Jing-Wei; Da Silva, Evandro; Shi, Xiao-Xia; Cao, Yue; Rathinasabapathi, Bala; Chen, Yanshan; Ma, Lena Q

    2017-04-01

    Arsenic (As) in soils is often adsorbed on Fe-(hydro)oxides surface, rendering them more resistant to dissolution, which is undesirable for phytoremediation of As-contaminated soils. Arsenic hyperaccumulator Pteris vittata prefers to grow in calcareous soils where available Fe and As are low. To elucidate its mechanisms of acquiring Fe and As from insoluble sources in soils, we investigated dissolution of goethite with pre-adsorbed arsenate (AsV; As-goethite) in presence of four organic ligands, including two root exudates (oxalate and phytate, dominant in P. vittata) and two microbial siderophores (PG12-siderophore and desferrioxamine B). Their presence increased As solubilization from As-goethite from 0.03 to 0.27-5.33 mg L(-1) compared to the control. The siderophore/phytate bi-ligand treatment released 7.42 mg L(-1) soluble Fe, which was 1.2-fold that of the sum of siderophore and phytate, showing a synergy in promoting As-goethite dissolution. In the ligand-mineral-plant system, siderophore/phytate was most effective in releasing As and Fe from As-goethite. Moreover, the continuous plant uptake induced more As-goethite dissolution. The continued release of As and Fe significantly enhanced their plant uptake (from 0.01 to 0.43 mg plant(-1) As and 2.7-14.8 mg plant(-1) Fe) and plant growth (from 1.2 to 3.1 g plant(-1) fw) in P. vittata. Since microbial siderophores and root exudates often coexist in soil rhizosphere, their synergy in enhancing dissolution of insoluble As-Fe minerals may play an important role in efficient phytoremediation of As-contaminated soils.

  12. Solubilization, partial purification and properties of N-methylglutamate dehydrogenase from Pseudomonas aminovorans.

    PubMed Central

    Bamforth, C W; Large, P J

    1977-01-01

    1. Extracts of amine-grown Pseudomonas aminovorans contained a particle-bound N-methylglutamate dehydrogenase (EC 1.5.99.5). The enzyme was not present in succinate-grown cells, and activity appeared before growth began in succinate-grown cells which had been transferred to methylamine growth medium. 2. Membrane-containing preparations from methylamine-grown cells catalysed an N-methylglutamate-dependent uptake of O2 or reduction of cytochrome c, which was sensitive to inhibitors of the electron-transport chain. 3. N-Methylglutamate dehydrogenase activity with phenazine methosulphate or 2,6-dichlorophenol-indophenol as electron acceptor could be solubilized with 1% (w/v) Triton X-100. The solubilized enzyme was much less active with cytochrome c as electron acceptor and did not sediment in 1 h at 150000g. Solubilization was accompanied by a change in the pH optimum for activity. 4. The solubilized enzyme was partially purified by Sepharose 4B and hydroxyapatite chromatograpy to yield a preparation 22-fold increased in specific activity over the crude extract. 5. The partially-purified enzyme was active with sarcosine, N-methylalanine and N-methylaspartate as well as with N-methylglutamate. Evidence suggesting activity with N-methyl D-amino acids as well as with the L-forms was obtained. 6. The enzyme was inhibited by p-chloromercuribenzoate, iodoacetamide and by both ionic and non-ionic detergents. 2-Oxoglutarate and formaldehyde were also inhibitors. 7. Kinetic analysis confirmed previous workers' observations of a group transfer (Ping Pong) mechanism. 8. Spectral observations suggested that the partially purified preparation contained flavoprotein and a b-type cytochrome. 9. The role of the enzyme in the oxidation of methylamine is discussed. PMID:15545

  13. Effects of ethanol addition on micellar solubilization and plume migration during surfactant enhanced recovery of tetrachloroethene

    NASA Astrophysics Data System (ADS)

    Taylor, Tammy P.; Rathfelder, Klaus M.; Pennell, Kurt D.; Abriola, Linda M.

    2004-03-01

    Alcohol addition has been suggested for use in combination with surfactant flushing to enhance solubilization kinetics and permit density control of dense non-aqueous phase liquid (DNAPL)-laden surfactant plumes. This study examined the effects of adding ethanol (EtOH) to a 4% Tween 80 (polyoxyethylene (20) sorbitan monooleate) solution used to flush tetrachloroethene (PCE)-contaminated porous media. The influence of EtOH concentration, subsurface layering and scale on flushing solution delivery and PCE recovery was investigated through a combination of experimental and mathematical modeling studies. Results of batch experiments demonstrated that the addition of 2.5%, 5% and 10% (wt.) EtOH incrementally increased the PCE solubilization capacity and viscosity of the surfactant solution, while reducing solution density from 1.002 to 0.986 g/cm 3. Effluent concentration data obtained from one-dimensional (1-D) column experiments were used to characterize rate-limited micellar solubilization of residual PCE, which was strongly dependent upon flow velocity and weakly dependent upon EtOH concentration. Two-dimensional (2-D) box studies illustrated that minor differences (0.008 g/cm 3) between flushing and resident solution density can strongly influence surfactant front propagation. A two-dimensional multiphase simulator, MISER, was used to model the influence of EtOH composition on the aqueous flow field and PCE mass recovery. The ability of the numerical simulator to predict effluent concentrations and front propagation was demonstrated for both 1-D columns and 2-D boxes flushed with EtOH-amended Tween 80 solutions. Results of this study quantify the potential influence of alcohol addition on surfactant solution properties and solubilization capacity, and demonstrate the importance of considering small density variations in remedial design.

  14. Binding properties of solubilized gonadotropin-releasing hormone receptor: role of carboxylic groups

    SciTech Connect

    Hazum, E.

    1987-11-03

    The interaction of /sup 125/I-buserelin, a superactive agonist of gonadotropin-releasing hormone (GnRH), with solubilized GnRH receptor was studied. The highest specific binding of /sup 125/I-buserelin to solubilized GnRH receptor is evident at 4/sup 0/C, and equilibrium is reached after 2 h of incubation. The soluble receptor retained 100% of the original binding activity when kept at 4 or 22/sup 0/C for 60 min. Mono- and divalent cations inhibited, in a concentration-dependent manner, the binding of /sup 125/I-buserelin to solubilized GnRH receptor. Monovalent cations require higher concentrations than divalent cations to inhibit the binding. Since the order of potency with the divalent cations was identical with that of their association constants to dicarboxylic compounds, it is suggested that there are at least two carboxylic groups of the receptor that participate in the binding of the hormone. The carboxyl groups of sialic acid residues are not absolutely required for GnRH binding since the binding of /sup 125/I-buserelin to solubilized GnRH receptor was only slightly affected by pretreatment with neuraminidase and wheat germ agglutinin. The finding that polylysines stimulate luteinizing hormone (LH) release from pituitary cell cultures with the same efficacy as GnRH suggest that simple charge interactions can induce LH release. According to these results, the authors propose that the driving force for the formation of the hormone-receptor complex is an ionic interaction between the positively charged amino acid arginine in position 8 and the carboxyl groups in the binding site.

  15. Solubilization and reconstitution of the formylmethionylleucylphenylalanine receptor coupled to guanine nucleotide regulatory protein

    SciTech Connect

    Williamson, K.; Dickey, B.F.; Pyun, H.Y.; Navarro, J.

    1988-07-12

    The authors describe the solubilization, resolution, and reconstitution of the formylmethionylleucylphenylalanine (fMet-Leu-Phe) receptor and guanine nucleotide regulatory proteins (G-proteins). The receptor was solubilized with 3-((3-cholamidopropyl)dimethylammonio)-1-propanesulfonate. Guanine nucleotides decreased the number of high-affinity binding sites and accelerated the rate of dissociation of the receptor-ligand complex, suggesting that the solubilized receptor remained coupled to endogenous G-proteins. The solubilized receptor was resolved from endogenous G-proteins by fractionation on a wheat germ agglutinin (WGA)-Sepharose 4B column. High-affinity (/sup 3/H)fMet-Leu-Phe binding to the WGA-purified receptor was diminished and exhibited reduced guanine nucleotide sensitivity. High-affinity (/sup 3/H)fMET-Leu-Phe binding and guanine nucleotide sensitivity were reconstituted upon the addition of purified brain G-proteins. Similar results were obtained when the receptor was reconstituted with brain G-proteins into phospholipid vesicles by gel filtration chromatography. In addition, they also demonstrated fMET-Leu-Phe-dependent GTP hydrolysis in the reconstituted vesicles. The results of this work indicate that coupling of the fMet-Leu-Phe receptor to G-proteins converts the receptor to a high-affinity binding state and that agonist produces activation of G-proteins. The resolution and functional reconstitution of this receptor should provide an important step toward the elucidation of the molecular mechanism of the fMet-Leu-Phe transduction system in neutrophils.

  16. High temperature flow-through device for rapid solubilization and analysis

    SciTech Connect

    West, Jason A. A.; Hukari, Kyle W.; Patel, Kamlesh D.; Peterson, Kenneth A.; Renzi, Ronald F.

    2009-09-22

    Devices and methods for thermally lysing of biological material, for example vegetative bacterial cells and bacterial spores, are provided. Hot solution methods for solubilizing bacterial spores are described. Systems for direct analysis are disclosed including thermal lysers coupled to sample preparation stations. Integrated systems capable of performing sample lysis, labeling and protein fingerprint analysis of biological material, for example, vegetative bacterial cells, bacterial spores and viruses are provided.

  17. High temperature flow-through device for rapid solubilization and analysis

    DOEpatents

    West, Jason A. A.; Hukari, Kyle W.; Patel, Kamlesh D.; Peterson, Kenneth A.; Renzi, Ronald F.

    2013-04-23

    Devices and methods for thermally lysing of biological material, for example vegetative bacterial cells and bacterial spores, are provided. Hot solution methods for solubilizing bacterial spores are described. Systems for direct analysis are disclosed including thermal lysers coupled to sample preparation stations. Integrated systems capable of performing sample lysis, labeling and protein fingerprint analysis of biological material, for example, vegetative bacterial cells, bacterial spores and viruses are provided.

  18. Initial pH of medium affects organic acids production but do not affect phosphate solubilization

    PubMed Central

    Marra, Leandro M.; de Oliveira-Longatti, Silvia M.; Soares, Cláudio R.F.S.; de Lima, José M.; Olivares, Fabio L.; Moreira, Fatima M.S.

    2015-01-01

    The pH of the culture medium directly influences the growth of microorganisms and the chemical processes that they perform. The aim of this study was to assess the influence of the initial pH of the culture medium on the production of 11 low-molecular-weight organic acids and on the solubilization of calcium phosphate by bacteria in growth medium (NBRIP). The following strains isolated from cowpea nodules were studied: UFLA03-08 (Rhizobium tropici), UFLA03-09 (Acinetobacter sp.), UFLA03-10 (Paenibacillus kribbensis), UFLA03-106 (Paenibacillus kribbensis) and UFLA03-116 (Paenibacillus sp.). The strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 solubilized Ca3(PO4)2 in liquid medium regardless of the initial pH, although without a significant difference between the treatments. The production of organic acids by these strains was assessed for all of the initial pH values investigated, and differences between the treatments were observed. Strains UFLA03-09 and UFLA03-10 produced the same acids at different initial pH values in the culture medium. There was no correlation between phosphorus solubilized from Ca3(PO4)2 in NBRIP liquid medium and the concentration of total organic acids at the different initial pH values. Therefore, the initial pH of the culture medium influences the production of organic acids by the strains UFLA03-08, UFLA03-09, UFLA03-10 and UFLA03-106 but it does not affect calcium phosphate solubilization. PMID:26273251

  19. Nanolipoprotein particles and related methods and systems for protein capture, solubilization, and/or purification

    DOEpatents

    Chromy, Brett A; Henderson, Paul; Hoeprich, Jr., Paul D

    2014-12-09

    Provided herein are methods and systems for assembling, solubilizing and/or purifying a membrane associated protein in a nanolipoprotein particle, which comprise a temperature transition cycle performed in presence of a detergent, wherein during the temperature transition cycle the nanolipoprotein components are brought to a temperature above and below the gel to liquid crystalling transition temperature of the membrane forming lipid of the nanolipoprotein particle.

  20. Nanolipoprotein particles and related methods and systems for protein capture, solubilization, and/or purification

    DOEpatents

    Chromy, Brett A.; Henderson, Paul; Hoeprich, Jr, Paul D.

    2016-10-04

    Provided herein are methods and systems for assembling, solubilizing and/or purifying a membrane associated protein in a nanolipoprotein particle, which comprise a temperature transition cycle performed in presence of a detergent, wherein during the temperature transition cycle the nanolipoprotein components are brought to a temperature above and below the gel to liquid crystalling transition temperature of the membrane forming lipid of the nanolipoprotein particle.

  1. Real-time detection of lipid bilayer assembly and detergent-initiated solubilization using optical cavities

    NASA Astrophysics Data System (ADS)

    Sun, V.; Armani, A. M.

    2015-02-01

    The cellular membrane governs numerous fundamental biological processes. Therefore, developing a comprehensive understanding of its structure and function is critical. However, its inherent biological complexity gives rise to numerous inter-dependent physical phenomena. In an attempt to develop a model, two different experimental approaches are being pursued in parallel: performing single cell experiments (top down) and using biomimetic structures (bottom up), such as lipid bilayers. One challenge in many of these experiments is the reliance on fluorescent probes for detection which can create confounds in this already complex system. In the present work, a label-free detection method based on an optical resonant cavity is used to detect one of the fundamental physical phenomena in the system: assembly and solubilization of the lipid bilayer. The evanescent field of the cavity strongly interacts with the lipid bilayer, enabling the detection of the bilayer behavior in real-time. Two independent detection mechanisms confirm the formation and detergent-assisted solubilization of the lipid bilayers: (1) a refractive index change and (2) a material loss change. Both mechanisms can be monitored in parallel, on the same device, thus allowing for cross-confirmation of the results. To verify the proposed method, we have detected the formation of self-assembled phosphatidylcholine lipid bilayers from small unilamellar vesicles on the device surface in real-time. Subsequently, we exposed the bilayers to two different detergents (non-ionic Triton X-100 and anionic sodium dodecyl sulfate) to initiate solubilization, and this process was also detected in real-time. After the bilayer solubilization, the device returned to its initial state, exhibiting minimal hysteresis. The experimental wash-off was also collected and analyzed using dynamic light scattering.

  2. Reduction of tomato polygalacturonase beta subunit expression affects pectin solubilization and degradation during fruit ripening.

    PubMed Central

    Watson, C F; Zheng, L; DellaPenna, D

    1994-01-01

    The developmental changes that accompany tomato fruit ripening include increased solubilization and depolymerization of pectins due to the action of polygalacturonase (PG). Two PG isoenzymes can be extracted from ripe fruit: PG2, which is a single catalytic PG polypeptide, and PG1, which is composed of PG2 tightly associated with a second noncatalytic protein, the beta subunit. Previous studies have correlated ripening-associated increases in pectin solubilization and depolymerization with the presence of extractable PG1 activity, prior to the appearance of PG2, suggesting a functional role for the beta subunit and PG1 in pectin metabolism. To assess the function of the beta subunit, we produced and characterized transgenic tomatoes constitutively expressing a beta subunit antisense gene. Fruit from antisense lines had greatly reduced levels of beta subunit mRNA and protein and accumulated < 1% of their total extractable PG activity in ripe fruit as PG1, as compared with 25% for wild type. Inhibition of beta subunit expression resulted in significantly elevated levels of EDTA-soluble polyuronides at all stages of fruit ripening and a significantly higher degree of depolymerization at later ripening stages. Decreased beta subunit protein and extractable PG1 enzyme activity and increased pectin solubility and depolymerization all cosegregated with the beta subunit antisense transgene in T2 progeny. These results indicate (1) that PG2 is responsible for pectin solubilization and depolymerization in vivo and (2) that the beta subunit protein is not required for PG2 activity in vivo but (3) does play a significant role in regulating pectin metabolism in wild-type fruit by limiting the extent of pectin solubilization and depolymerization that can occur during ripening. Whether this occurs by direct interaction of the beta subunit with PG2 or indirectly by interaction of the beta subunit with the pectic substrate remains to be determined. PMID:7827495

  3. On the mechanism of solubilization of drugs in the presence of poorly soluble additives.

    PubMed

    Boldyrev, V V; Shakhtshneider, T P; Chizhik, S A

    2005-05-13

    A model is proposed which describes the solubilization of a poorly soluble drug in the presence of an insoluble excipient which forms an easily soluble compound with the drug. For sulfathiazole-calcium carbonate system as an example, it is demonstrated using sulfathiazole single crystals and powdered samples that the presence of insoluble additive causes an increase in dissolution rate and solubility of the drug.

  4. Molecular identification of phosphate-solubilizing native bacteria isolated from the rhizosphere of Prosopis glandulosa in Mexicali valley.

    PubMed

    Moreno-Ramírez, L; González-Mendoza, D; Cecena-Duran, C; Grimaldo-Juarez, O

    2015-03-31

    One of the main limitations in intensive crop production in Northwestern Mexico is the dependence on the use of phosphate fertilizer. In this study, we isolated indigenous microorganisms with phosphate solubilization capacities from mesquite (Prosopis glandulosa) present in the Mexicali valley. In total, 4 bacteria were isolated from the rhizosphere of mesquite, including ICA01, ICA02Ba, ICA03Bs, and ICA04Ma. The bacterial isolates were identified based on their phenotypic and 16S rRNA gene sequencing data to be Acinetobacter calcoaceticus. The results showed that ICA01 was the most efficient in solubilizing phosphate, followed by ICA02Ba and ICA03Bs, while ICA04Ma showed the lowest phosphate-solubilizing activity. The pH value of the culture medium decreased with bacterial growth, suggesting that these strains produce organic acids that solubilize phosphorus. These results will be useful for biotechnological studies and A. calcoaceticus may be employed for biofertilization programs in northwest Mexico.

  5. Solubilization of Tea Seed Oil in a Food-Grade Water-Dilutable Microemulsion

    PubMed Central

    Deng, Lingli; Que, Fei; Wei, Hewen; Xu, Guangwei; Dong, Xiaowei; Zhang, Hui

    2015-01-01

    Food-grade microemulsions containing oleic acid, ethanol, Tween 20, and water were formulated as a carrier system for tea seed oil (Camellia oleifera Abel.). The effect of ethanol on the phase behavior of the microemulsion system was clearly reflected in pseudo-ternary diagrams. The solubilization capacity and solubilization efficiency of tea seed oil dispersions were measured along the dilution line at a 70/30 surfactant/oil mass ratio with Tween 20 as the surfactant and oleic acid and ethanol (1:3, w/w) as the oil phase. The dispersed phase of the microemulsion (1.5% weight ratio of tea seed oil to the total amount of oil, surfactant, and tea seed oil) could be fully diluted with water without phase separation. Differential scanning calorimetry and viscosity measurements indicated that both the carrier and solubilized systems underwent a similar microstructure transition upon dilution. The dispersion phases gradually inverted from the water-in-oil phase (< 35% water) to the bicontinuous phase (40–45% water) and finally to the oil-in-water phase (> 45% water) along the dilution line. PMID:25996147

  6. Comparison of solubilized and purified plasma membrane and nuclear insulin receptors

    SciTech Connect

    Wong, K.Y.; Hawley, D.; Vigneri, R.; Goldfine, I.D.

    1988-01-12

    Prior studies have detected biochemical and immunological differences between insulin receptors in plasma membranes and isolated nuclei. To further investigate these receptors, they were solubilized in Triton X-100 partially purified by wheat germ agglutinin-agarose chromatography. In these preparations, the nuclear and plasma membrane receptors had very similar pH optima (pH 8.0) and reactivities to a group of polyclonal antireceptor antibodies. Further, both membrane preparations had identical binding activities when labeled insulin was competed for by unlabeled insulin (50% inhibition at 800 pM). Next, nuclear and plasma membranes were solubilized and purified to homogeneity by wheat germ agglutinin-agarose and insulin-agarose chromatography. In both receptors, labeled insulin was covalently cross-linked to a protein of 130 kilodaltons representing the insulin receptor ..cap alpha.. subunit. When preparations of both receptors were incubated with insulin and then adenosine 5'-(..gamma..-/sup 32/P)triphosphate, a protein of 95 kilodaltons representing the insulin receptor ..beta.. subunit was phosphorylated in a dose-dependent manner. These studies indicate, therefore, that solubilized plasma membrane and nuclear insulin receptors have similar structures and biochemical properties, and they suggest that they are the same (or very similar) proteins.

  7. Phase behavior of TXs/toluene/water microemulsion systems for solubilization absorption of toluene.

    PubMed

    Liu, Lian; Tian, Senlin; Ning, Ping

    2010-01-01

    Triton Xs (TXs) surfactants/cosurfactant/water/oil (toluene) microemulsion systems for enhancing toluene solubilization were proposed and its potential was investigated for toluene removal from gas stream. The results indicated that TX-100 was superior to other TXs surfactants in removing toluene without cosurfactant. The efficiency of cosurfactants for improving toluene solubilization capacity follows the order: amine > alcohol > acid. According to the factor analysis, the linear cosurfactants are better than the branched ones. The effects of hydrophile-lipophile balance (HLB), salt (NaCl) concentration and temperature on the formation of microemulsion system were also discussed. The results suggested that the optimum value of HLB was 15, the effect of NaCl concentration on the system was inconspicuous and the lower temperature enhanced the solubilization capacity. Nonionic surfactant-based microemulsions had a significant absorption enhancement for toluene, indicated by as much as 82.72% of toluene in phase composition diagram, which will have a great prospect in air pollution treatment.

  8. Effect of solubilizing agents on mupirocin loading into and release from PEGylated nanoliposomes.

    PubMed

    Cern, Ahuva; Nativ-Roth, Einat; Goldblum, Amiram; Barenholz, Yechezkel

    2014-07-01

    Mupirocin was identified by quantitative structure property relationship models as a good candidate for remote liposomal loading. Mupirocin is an antibiotic that is currently restricted to topical administration because of rapid hydrolysis in vivo to its inactive metabolite. Formulating mupirocin in PEGylated nanoliposomes may potentially expand its use to parenteral administration by protecting it from degradation in the circulation and target it (by the enhanced permeability effect) to the infected tissue. Mupirocin is slightly soluble in aqueous medium and its solubility can be increased using solubilizing agents. The effect of the solubilizing agents on mupirocin remote loading was studied when the solubilizing agents were added to the drug loading solution. Propylene glycol was found to increase mupirocin loading, whereas polyethylene glycol 400 showed no effect. Hydroxypropyl-β-cyclodextrin (HPCD) showed a concentration-dependent effect on mupirocin loading; using the optimal HPCD concentration increased loading, but higher concentrations inhibited it. The inclusion of HPCD in the liposome aqueous phase while forming the liposomes resulted in increased drug loading and substantially inhibited drug release in serum.

  9. Polysorbate 80 and Cremophor EL micelles deaggregate and solubilize nystatin at the core-corona interface.

    PubMed

    Croy, Scott R; Kwon, Glen S

    2005-11-01

    The extent and the location of nystatin solubilization by nonionic surfactant micelles were determined. The critical aggregation concentrations (CAC) of nystatin in 4 x 10(-3) M surfactant were determined by dynamic light scattering. The resulting CAC values for nystatin in Cremophor EL (CrEL), Tween 80 (T80), and Nofable ESO-9920 (NOF) were 150, 150, and 300 microM compared to 10 microM for the phosphate-buffered saline (PBS) control. The surfactants were able to solubilize and deaggregate nystatin from 50 to 75 times more than the PBS control. The core polarity of CrEL micelles, determined by pyrene fluorescence, was significantly lower than T80 and NOF micelles. The micelle-water partition coefficients (P) of nystatin and pyrene were determined by fluorescence spectroscopy. The partition coefficient values of 7.5 microM nystatin in CrEL and NOF micelles were 1100 +/- 60 and 1000 +/- 110, an insignificant difference (p > 0.1). However, there was a significant increase in pyrene partitioning in micelles with lower core polarity. Additionally, the P of nystatin decreased when the nystatin concentration was increased, whereas the pyrene P did not. The unusual partitioning behavior of nystatin revealed a good fit with the Langmuir adsorption isotherm, indicating solubilization at the micellar core-corona interface.

  10. Silica nanoparticle stabilization of liquid crystalline lipid dispersions: impact on enzymatic digestion and drug solubilization.

    PubMed

    Bhatt, Achal B; Barnes, Timothy J; Prestidge, Clive A

    2015-01-01

    The high internal surface area and drug solubilizing capacity of liquid crystal lipids makes them promising oral drug delivery systems. Pluronic F127 is typically used to disperse highly viscous cubic liquid crystal lipids into cubosomes; however, such copolymers alter the internal structure and provide little control over enzymatic digestion. This study aimed to use hydrophilic silica nanoparticles to stabilize glyceryl monooleate (GMO) cubosomes prepared by ultrasonication. We investigate the influence of silica nanoparticles size and concentration on the physical (colloidal) and chemical (enzymatic digestion) stability, as well as in vitro solubilization of cinnarizine as a poorly soluble model drug. Silica stabilized nanostructured liquid crystal dispersions (120 nm to150 nm in diameter and zeta potentials of-30 mV to -60 mV) were successfully prepared with excellent long-term stability (<10% size change after 30 days). Silica stabilized GMO cubosomes demonstrated reduced enzymatic digestion compared to pluronic F127 stabilized cubosomes. This reduced digestion was attributed to a combination of adsorbed silica nanoparticles acting as a physical barrier and excess dispersed silica adsorbing/scavenging the lipase enzyme. Under simulated intestinal digestion conditions, silica stabilized GMO cubosomes showed a greater solubilization capacity for cinnarizine, which precipitated in non-crystalline form, in comparison to pure drug suspensions or pluronic F127 stabilized GMO cubosomes. Silica nanoparticle stabilized GMO liquid crystal dispersions are a promising oral delivery vehicle.

  11. Oral Solubilized Ursodeoxycholic Acid Therapy in Amyotrophic Lateral Sclerosis: A Randomized Cross-Over Trial

    PubMed Central

    Min, Ju-Hong; Hong, Yoon-Ho; Sung, Jung-Joon; Kim, Sung-Min; Lee, Jung Bok

    2012-01-01

    To evaluate the efficacy and safety of ursodeoxycholic acid (UDCA) with oral solubilized formula in amyotrophic lateral sclerosis (ALS) patients, patients with probable or definite ALS were randomized to receive oral solubilized UDCA (3.5 g/140 mL/day) or placebo for 3 months after a run-in period of 1 month and switched to receive the other treatment for 3 months after a wash-out period of 1 month. The primary outcome was the rate of progression, assessed by the Appel ALS rating scale (AALSRS), and the secondary outcomes were the revised ALS functional rating scale (ALSFRS-R) and forced vital capacity (FVC). Fifty-three patients completed either the first or second period of study with only 16 of 63 enrolled patients given both treatments sequentially. The slope of AALSRS was 1.17 points/month lower while the patients were treated with UDCA than with placebo (95% CI for difference 0.08-2.26, P = 0.037), whereas the slopes of ALSFRS-R and FVC did not show significant differences between treatments. Gastrointestinal adverse events were more common with UDCA (P < 0.05). Oral solubilized UDCA seems to be tolerable in ALS patients, but we could not make firm conclusion regarding its efficacy, particularly due to the high attrition rate in this cross-over trial. PMID:22323869

  12. Solubilizing properties of new surface-active agents, products of catalytic oxyethylation of cholic acid.

    PubMed

    Kołodziejczyk, Michał Krzysztof; Nachajski, Michal Jakub; Lukosek, Marek; Zgoda, Marian Mikołaj

    2013-01-01

    Solubilizing properties of aqueous solutions of a series of surface-active agents, products of oxyethylation of cholic acid, were examined in the present study. The content of oxyethylated segments determined by means of the 1H NMR method enabled the verification of the molecular mass of surfactants along with the calculation of the structural hydrophilic-lipophilic balance (HLB), the solubility parameter delta1/2, and the required solubility level of balance HLB(R). Viscosimetric measurements enabled the calculation of the limiting viscosity number, the content-average molecular mass, the effective volume, the hydrodynamic radius of the surfactant micelle and their equilibrium adducts with rutin, diclofenac and loratadine (BCS Class II and III). By means of the spectrophotometric method (UV) the amount of the solubilized diclofenac, loratadine and rutin (rutoside) was determined in the equilibrium system (saturated solution) in the environment of aqueous solutions of cholic acid derivatives of n(TE) = 20-70. The obtained results serve as a basis for determining the solubilization mechanism of lipophilic therapeutic products and indirectly for estimating the influence of the above process on pharmaceutical as well as biological availability of a micellar adduct from model drug forms (Lindbladt lithogenolitic index).

  13. Arsenic-hyperaccumulator Pteris vittata efficiently solubilized phosphate rock to sustain plant growth and As uptake.

    PubMed

    Fu, Jing-Wei; Liu, Xue; Han, Yong-He; Mei, Hanyi; Cao, Yue; de Oliveira, Letuzia M; Liu, Yungen; Rathinasabapathi, Bala; Chen, Yanshan; Ma, Lena Q

    2017-01-31

    Phosphorus (P) is one of the most important nutrients for phytoremediation of arsenic (As)-contaminated soils. In this study, we demonstrated that As-hyperaccumulator Pteris vittata was efficient in acquiring P from insoluble phosphate rock (PR). When supplemented with PR as the sole P source in hydroponic systems, P. vittata accumulated 49% and 28% higher P in the roots and fronds than the -P treatment. In contrast, non-hyperaccumulator Pteris ensiformis was unable to solubilize P from PR. To gain insights into PR solubilization by plants, organic acids in plant root exudates were analyzed by HPLC. The results showed that phytic acid was the predominant (>90%) organic acid in P. vittata root exudates whereas only oxalic acid was detected in P. ensiformis. Moreover, P. vittata secreted more phytic acid in -P and PR treatments. Compared to oxalic acid, phytic acid was more effective in solubilizing PR, suggesting that phytic acid was critical for PR utilization. Besides, secretion of phytic acid by P. vittata was not inhibited by arsenate. Our data indicated that phytic acid played an important role in efficient use of insoluble PR by P. vittata, shedding light on using insoluble PR to enhance phytoremediation of As-contaminated soils.

  14. Solubilization of trace organics in block copolymer micelles for environmental separation using membrane extraction principles

    SciTech Connect

    Hatton, T.A.

    1992-12-01

    The solubilization of a range of polycyclic aromatic hydrocarbons in block copolymer micelles has been studied as a function of polymer composition, architecture, and temperature. Micelle formation is favored at high temperatures, leading to significant enhancements in solubilization capacity. At low temperatures, however, micelles do not form and the solubilization capacity of the block copolymer solution for the organics is low; this provides a convenient method for the regeneration of micellar solutions used as solvents'' in the treatment of contaminated feed streams using membrane extraction principles. It has also been shown (in collaboration with K.P. Johnston of University of Texas, Austin) that supercritical CO[sub 2] can be used effectively for micelle regeneration. Theoretical calculations of the structure of block copolymer micelles in the presence and absence of solutes using self-consistent mean-field lattice theories have successfully captured the trends observed with changing polymer composition and architecture, often quantitatively. The temperature and composition dependence of the micellar properties were determined by allowing the individual polymer segments to assume both polar and non-polar conformations.

  15. Biosurfactant-producing strains in enhancing solubilization and biodegradation of petroleum hydrocarbons in groundwater.

    PubMed

    Liu, Hong; Wang, Hang; Chen, Xuehua; Liu, Na; Bao, Suriguge

    2014-07-01

    Three biosurfactant-producing strains designated as BS-1, BS-3, and BS-4 were screened out from crude oil-contaminated soil using a combination of surface tension measurement and oil spreading method. Thin layer chromatography and infrared analysis indicated that the biosurfactants produced by the three strains were lipopeptide, glycolipid, and phospholipid. The enhancement of solubilization and biodegradation of petroleum hydrocarbons in groundwater employing biosurfactant-producing strains was investigated. The three strain mixtures led to more solubilization of petroleum hydrocarbons in groundwater, and the solubilization rate was 10.5 mg l−1. The combination of biosurfactant-producing strains and petroleum-degrading strains exhibited a higher biodegradation efficiency of 85.4 % than the petroleum-degrading strains (71.2 %). Biodegradation was enhanced the greatest with biosurfactant-producing strains and petroleum-degrading strains in a ratio of 1:1. Fluorescence microscopy images illustrate that the oil dispersed into smaller droplets and emulsified in the presence of biosurfactant-producing strains, which attached to the oil. Thus, the biodegradation of petroleum hydrocarbons in groundwater was enhanced.

  16. Solubilization sites and acid-base forms of dibucaine-hydrochloride in neutral and charged micellar solutions.

    PubMed

    Mertz, C J; Lin, C T

    1991-03-01

    Steady-state and time-resolved emission spectroscopic techniques have been employed to characterize the drug species of dibucaine and to identify its location in micellar Triton X-100 (neutral), hexadecyltrimethyl ammonium bromide (cationic) and lithium dodecyl sulfate (anionic) solutions at 77 K. Under physiological conditions, the dibucaine is shown to exist in the free base form (D) while solubilized in the hydrocarbon core of neutral micelles. In cationic micellar solution, dibucaine exists as the monocation species (DH+) where the anesthetic is solubilized in the extramicellar aqueous solution and D is solubilized in the hydrophobic region with close proximity to the micellar interface. In the anionic micelles, interfacial solubilization is most consistent with a site in which the tertiary amino group of the monocation dibucaine (DH+) is anchored at the micellar interface with its quinoline analog penetrating the hydrophobic region. The distinct properties observed for the drug species (i.e. D and DH+) and their solubilization sites in micelles are consistent with a balance between hydrophobic forces, surface polarity and the interfacial electrostatic potential present in the micellar solubilization sites. These observations could lend insight into the molecular basis of pharmacological action, in particular the mechanism of local anesthetic drug transport across membranes.

  17. Recovery of active N-acetyl-D-glucosamine 2-epimerase from inclusion bodies by solubilization with non-denaturing buffers.

    PubMed

    Lu, Shih-Chin; Lin, Sung-Chyr

    2012-01-05

    Overexpression of recombinant N-acetyl-D-glucosamine 2-epimerase, one of the key enzymes for the synthesis of N-acetylneuraminic acid, in E. coli led to the formation of protein inclusion bodies. In this study we report the recovery of active epimerase from inclusion bodies by direct solubilization with Tris buffer. At pH 7.0, 25% of the inclusion bodies were solubilized with Tris buffer. The specific activity of the solubilized proteins, 2.08±0.02 U/mg, was similar to that of the native protein, 2.13±0.01 U/mg. The result of circular dichroism spectroscopy analysis indicated that the structure of the solubilized epimerase obtained with pH 7.0 Tris buffer was similar to that of the native epimerase purified from the clarified cell lysate. As expected, the extent of deviation in CD spectra increased with buffer pH. The total enzyme activity recovered by solubilization from inclusion bodies, 170.41±10.06 U/l, was more than 2.5 times higher than that from the clarified cell lysate, 67.32±5.53 U/l. The results reported in this study confirm the hypothesis that the aggregation of proteins into inclusion bodies is reversible and suggest that direct solubilization with non-denaturing buffers is a promising approach for the recovery of active proteins from inclusion bodies, especially for aggregation-prone multisubunit proteins.

  18. Generally recognized as safe (GRAS) Lactococcus lactis strains associated with Lippia sidoides Cham. are able to solubilize/mineralize phosphate.

    PubMed

    de Lacerda, Jackeline Rossetti Mateus; da Silva, Thais Freitas; Vollú, Renata Estebanez; Marques, Joana Montezano; Seldin, Lucy

    2016-01-01

    Eight strains isolated from the stems of Lippia sidoides were identified as belonging to Lactococcus lactis, a bacterial species considered as "generally recognized as safe". Their capacity to solubilize/mineralize phosphate was tested in vitro with different inorganic and organic phosphorus (P) sources. All strains were able to solubilize calcium phosphate as an inorganic P source, and the best result was observed with strain 003.41 which solubilized 31 % of this P source. Rock phosphate, a mined rock containing high amounts of phosphate bearing minerals, was solubilized by five strains. When calcium phytate was the organic P source used, the majority of the strains tested showed phosphate mineralization activity. Moreover, all strains were able to solubilize/mineralize phosphate from poultry litter, a complex P source containing inorganic and predominantly organic P. The presence of genes coding for phytase and alkaline phosphatase was searched within the strains studied. However, only gene sequences related to alkaline phosphatase (phoA and phoD) could be detected in the majority of the strains (excepting strain 006.29) with identities varying from 67 to 88 %. These results demonstrate for the first time the potential of L. lactis strains for phosphate solubilization/mineralization activity using a broad spectrum of P sources; therefore, they are of great importance for the future development of more safe bioinoculants with possible beneficial effects for agriculture.

  19. The removal characteristics of natural organic matter in the recycling of drinking water treatment sludge: Role of solubilized organics.

    PubMed

    Zhou, Zhiwei; Yang, Yanling; Li, Xing; Ji, Siyang; Zhang, Hao; Wang, Shuai; Zeng, Qingping; Han, Xinghang

    2016-01-01

    To clarify the role of solubilized organics derived from drinking water treatment sludge (DWTS) in the elimination of natural organic matter (NOM) in the DWTS recycling process, a probe sonoreactor at a frequency of 25 kHz was used to solubilize the organics at varied specific energies. The coagulation behavior related to NOM removal in recycling the sonicated DWTS with and without solubilized organics was evaluated, and the effect on organic fractionations in coagulated water was determined. The study results could provide useful implications in designing DWTS recycling processes that avoid the enrichment of organic matter. Our results indicate that DWTS was disrupted through a low release of soluble chemical oxygen demand (SCOD) and proteins, which could deteriorate the coagulated water quality under the specific energy of 37.87-1212.1 kW h/kg TS. The optimal coagulation behavior for NOM removal was achieved by recycling the sonicated DWTS without solubilized organics at 151.5 kW h/kg TS specific energy. Recycling the sonicated DWTS could increase the enrichment potential of weakly hydrophobic acid, hydrophilic matter, and <3 kDa fractions; the enrichment risks could be reduced by discharging the solubilized organics. Fluorescent characteristic analysis indicated that when recycling the sonicated DWTS without solubilized organics, the removal of humic-like substances was limited, whereas removal of protein-like substances was enhanced, lowering the enrichment potential of protein-like substances.

  20. Solubilization and purification of the ATPase from the tonoplast of Hevea.

    PubMed

    Marin, B; Preisser, J; Komor, E

    1985-08-15

    The tonoplast-bound ATPase of Hevea brasiliensis (caoutchouc tree) was solubilized with dichloromethan and purified 100-fold with two ammonium sulfate precipitation steps and a G-200 gel filtration step. The resulting ATPase activity eluted according to a molecular mass of approximately 200 kDa and chromatographed at an isoelectric pH of 5.3. Subunits of molecular mass 110 kDa, 68 kDa, 24 kDa and 12 kDa appeared after treatment with 1% sodium dodecyl sulfate or spontaneously during storage of the solubilized ATPase. Dodecyl sulfate/polyacrylamide gel electrophoresis yielded four polypeptides of molecular mass 54 kDa, 66 kDa, 23 kDa and 13 kDa. From protein determination by ultraviolet absorption and Coomassie stain it appears that the 54-kDa and the 66-kDa polypeptides exist in multiple copies. No close resemblance to the membrane-bound ATPase of mitochondria, plastids, plasmalemma, chromaffin granules and synaptic vesicles is seen. No antibody cross-reaction to F1 of bacteria is observed. Therefore it is concluded that the vacuolar ATPase represents a novel type of ATPase. Many properties of the tonoplast-bound ATPase such as pH-dependence, substrate specificity, ion-dependence and inhibitor sensitivity did not change when the enzyme had been solubilized and purified. The phosphatase activity was lost during the purification procedure. The stimulation of ATP-hydrolysis in tonoplast vesicles by uncouplers and ionophores was absent in the solubilized ATPase, and also the stimulation by chloride was significantly reduced. Anion channel blockers, such as triphenyltin and 4,4'-diisothiocyano-2,2'-disulfonic acid stilbene, which are strong inhibitors of membrane-bound ATPase, fully or partly lost their inhibiting effect after solubilization of the ATPase. These results are interpreted to indicate that ionophores do not directly affect the ATPase molecule, whereas chloride might have a small direct effect on the ATPase besides its effect as a permeating anion.

  1. Pretreatment of piggery wastewater by a stable constructed microbial consortium for improving the methane production.

    PubMed

    Cai, Jian; Mo, Xiwei; Cheng, Guojun; Du, Dongyun

    2015-01-01

    A stable aerobic microbial consortium, established by successive subcultivation, was employed to solubilize the solid organic fraction in swine wastewater. In the 30 days' successive biological pretreatments, 30-38% of volatile solids and 19-28% total solids in raw slurry were solubilized after 10 hours at 37 °C. Meanwhile, soluble chemical oxygen demand (COD) and volatile fatty acid increased by 48%-56% and 600%-750%, respectively. Furthermore, the molecular microbial profile of the consortium in successive pretreatment was conducted by denaturing gradient gel electrophoresis (DGGE). The results indicated that bacterial species of the consortium rapidly overgrew the indigenous microbial community of raw water, and showed a stable predominance at the long-term treatment. As a consequence of biological pretreatment, pretreatment shortened digestion time by 50% and increased biogas production by 45% compared to raw water in the anaerobic process. The microbial consortium constructed herein is a potential candidate consortium for biological pretreatment of swine wastewater to enhance biogas production.

  2. Matrix Effects and Measuring Microbial Responses to Xenobiotics in Soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Compartmentalization due to tortuous pore space promotes great diversity and functional redundancy in unsaturated soils. It is difficult to simultaneously expose discontiguous pore space (and organisms therein) to the same substance, which creates some challenges in measuring microbial responses to ...

  3. Complete Genome of the Plant Growth-Promoting Rhizobacterium Pseudomonas putida BIRD-1

    SciTech Connect

    Matilla, M.A.; van der Lelie, D.; Pizarro-Tobias, P.; Roca, A.; Fernandez, M.; Duque, E.; Molina, L.; Wu, X.; Gomez, M. J.; Segura, A.; Ramos, J.-L.

    2011-03-01

    We report the complete sequence of the 5.7-Mbp genome of Pseudomonas putida BIRD-1, a metabolically versatile plant growth-promoting rhizobacterium that is highly tolerant to desiccation and capable of solubilizing inorganic phosphate and iron and of synthesizing phytohormones that stimulate seed germination and plant growth.

  4. Ileal and cecal microbial populations in broilers given specific essential oil blends and probiotics in two consecutive grow-outs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Digestive microbial populations (MP) are key components for sustained healthy broiler production. Specific essential oil (EO) blends and probiotics used as feed additives have shown to promote healthy digestive microbials, resulting in improved poultry production. Two consecutive experiments were ...

  5. Microbial starch-binding domain.

    PubMed

    Rodríguez-Sanoja, Romina; Oviedo, Norma; Sánchez, Sergio

    2005-06-01

    Glucosidic bonds from different non-soluble polysaccharides such as starch, cellulose and xylan are hydrolyzed by amylases, cellulases and xylanases, respectively. These enzymes are produced by microorganisms. They have a modular structure that is composed of a catalytic domain and at least one non-catalytic domain that is involved in polysaccharide binding. Starch-binding modules are present in microbial enzymes that are involved in starch metabolism; these are classified into several different families on the basis of their amino acid sequence similarities. Such binding domains promote attachment to the substrate and increase its concentration at the active site of the enzyme, which allows microorganisms to degrade non-soluble starch. Fold similarities are better conserved than sequences; nevertheless, it is possible to notice two evolutionary clusters of microbial starch-binding domains. These domains have enormous potential as tags for protein immobilization, as well as for the tailoring of enzymes that play a part in polysaccharide metabolism.

  6. Decreased solubilization of Pu(IV) polymers by humic acids under anoxic conditions

    NASA Astrophysics Data System (ADS)

    Xie, Jinchuan; Lin, Jianfeng; Liang, Wei; Li, Mei; Zhou, Xiaohua

    2016-11-01

    Pu(IV) polymer has a very low solubility (log[Pu(IV)aq]total = -10.4 at pH 7.2 and I = 0). However, some aspects of their environmental fate remain unclear. Humic acids are able to complex with Pu4+ ions and their dissolved species (<10 kD) in the groundwater (neutral to alkaline pH) may cause solubilization of the polymers. Also, humic acids have the native reducing capacity and potentially reduce the polymeric Pu(IV) to Pu(III)aq (log[Pu(III)aq]total = -5.3 at pH 7.2 and I = 0). Solubilization and reduction of the polymers can enhance their mobility in subsurface environments. Nevertheless, humic acids readily coat the surfaces of metal oxides via electrostatic interaction and ligand exchange mechanisms. The humic coatings are expected to prevent both solubilization and reduction of the polymers. Experiments were conducted under anoxic and slightly alkaline (pH 7.2) conditions in order to study whether humic acids have effects on stability of the polymers. The results show that the polymeric Pu(IV) was almost completely transformed into aqueous Pu(IV) in the presence of EDTA ligands. In contrast, the dissolved humic acids did not solubilize the polymers but in fact decreased their solubility by one order of magnitude. The humic coatings were responsible for the decreased solubilization. Such coatings limited the contact between the polymers and EDTA ligands, especially at the relatively high concentrations of humic acids (>0.57 mg/L). Solubilization of the humic-coated polymers was thus inhibited to a significant extent although EDTA, having the great complexation ability, was present in the humic solutions. Reduction of Pu(IV) polymers by the humic acids was also not observed in the absence of EDTA. In the presence of EDTA, the polymers were partially reduced to Pu(III)aq by the humic acids of 0.57 mg/L and the percentage of Pu(III)aq accounted for 51.7% of the total aqueous Pu. This demonstrates that the humic acids were able to reduce the aqueous Pu

  7. Expression, detergent solubilization, and purification of a membrane transporter, the MexB multidrug resistance protein.

    PubMed

    Bhatt, Forum H; Jeffery, Constance J

    2010-12-03

    Multidrug resistance (MDR), the ability of a cancer cell or pathogen to be resistant to a wide range of structurally and functionally unrelated anti-cancer drugs or antibiotics, is a current serious problem in public health. This multidrug resistance is largely due to energy-dependent drug efflux pumps. The pumps expel anti-cancer drugs or antibiotics into the external medium, lowering their intracellular concentration below a toxic threshold. We are studying multidrug resistance in Pseudomonas aeruginosa, an opportunistic bacterial pathogen that causes infections in patients with many types of injuries or illness, for example, burns or cystic fibrosis, and also in immuno-compromised cancer, dialysis, and transplantation patients. The major MDR efflux pumps in P. aeruginosa are tripartite complexes comprised of an inner membrane proton-drug antiporter (RND), an outer membrane channel (OMF), and a periplasmic linker protein (MFP). The RND and OMF proteins are transmembrane proteins. Transmembrane proteins make up more than 30% of all proteins and are 65% of current drug targets. The hydrophobic transmembrane domains make the proteins insoluble in aqueous buffer. Before a transmembrane protein can be purified, it is necessary to find buffer conditions containing a mild detergent that enable the protein to be solubilized as a protein detergent complex (PDC). In this example, we use an RND protein, the P. aeruginosa MexB transmembrane transporter, to demonstrate how to express a recombinant form of a transmembrane protein, solubilize it using detergents, and then purify the protein detergent complexes. This general method can be applied to the expression, purification, and solubilization of many other recombinantly expressed membrane proteins. The protein detergent complexes can later be used for biochemical or biophysical characterization including X-ray crystal structure determination or crosslinking studies.

  8. Macrophage solubilization and cytotoxicity of indium-containing particles in vitro.

    PubMed

    Gwinn, William M; Qu, Wei; Shines, Cassandra J; Bousquet, Ronald W; Taylor, Genie J; Waalkes, Michael P; Morgan, Daniel L

    2013-10-01

    Indium-containing particles (ICPs) are used extensively in the microelectronics industry. Pulmonary toxicity is observed after inhalation exposure to ICPs; however, the mechanism(s) of pathogenesis is unclear. ICPs are insoluble at physiological pH and are initially engulfed by alveolar macrophages (and likely airway epithelial cells). We hypothesized that uptake of ICPs by macrophages followed by phagolysosomal acidification results in the solubilization of ICPs into cytotoxic indium ions. To address this, we characterized the in vitro cytotoxicity of indium phosphide (InP) or indium tin oxide (ITO) particles with macrophages (RAW cells) and lung-derived epithelial (LA-4) cells at 24h using metabolic (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide) and membrane integrity (lactate dehydrogenase) assays. InP and ITO were readily phagocytosed by RAW and LA-4 cells; however, the particles were much more cytotoxic to RAW cells and cytotoxicity was dose dependent. Treatment of RAW cells with cytochalasin D (CytoD) blocked particle phagocytosis and reduced cytotoxicity. Treatment of RAW cells with bafilomycin A1, a specific inhibitor of phagolysosomal acidification, also reduced cytotoxicity but did not block particle uptake. Based on direct indium measurements, the concentration of ionic indium was increased in culture medium from RAW but not LA-4 cells following 24-h treatment with particles. Ionic indium derived from RAW cells was significantly reduced by treatment with CytoD. These data implicate macrophage uptake and solubilization of InP and ITO via phagolysosomal acidification as requisite for particle-induced cytotoxicity and the release of indium ions. This may apply to other ICPs and strongly supports the notion that ICPs require solubilization in order to be toxic.

  9. Solubilization and Partial Purification of the Adenosine Triphosphatase from a Corn Root Plasma Membrane Fraction

    PubMed Central

    Dupont, Frances M.; Leonard, Robert T.

    1980-01-01

    The K+-stimulated ATPase was partially purified from a plasma membrane fraction from corn roots (WF9 × Mo 17) by solubilization with 30 millimolar octyl-β-d-glucopyranoside followed by precipitation with dilute ammonium sulfate. The specific activity of the enzyme was increased about five times by this procedure. The molecular weight of the detergent-extracted ATPase complex was estimated to be at least 500,000 daltons by chromatography on a Bio-Gel A-5m column. Negative staining electron microscopy indicated that the detergent-extracted material consisted of amorphous particles, while the ammonium sulfate precipitate was composed of uniform vesicles with an average diameter of 100 nanometers. The protein composition of the ammonium sulfate precipitate was significantly different from that of the plasma membrane fraction when compared by sodium dodecyl sulfate gel electrophoresis. The characteristics of the partially purified ATPase resembled those of the plasma membrane associated enzyme. The ATPase required Mg2+, was further stimulated by K+, was almost completely inhibited by 0.1 millimolar diethylstilbestrol, and was not affected by 5.0 micrograms per milliliter oligomycin. Although the detergents sodium cholate, deoxycholate, Triton X-100 and Lubrol WX also solubilized some membrane protein, none solubilized the K+-stimulated ATPase activity. Low concentrations of each detergent, including octyl-β-d-glucopyranoside, activated the ATPase and higher concentrations inactivated the enzyme. These results suggest that the plasma membrane ATPase is a large, integral membrane protein or protein complex that requires lipids to maintain its activity. Images PMID:16661309

  10. Solubilization of the chromatin-bound estrogen receptor from chicken liver and fractionation on hydroxylapatite.

    PubMed

    Gschwendt, M

    1976-08-16

    1. High-affinity estrogen-binding sites can be solubilized from the liver chromatin of estrogenized chickens by treatment of the chromatin with 2 M KCL/5 M urea and fractionation on hydroxylapatite. Two estrogen-binding proteins are eluted from hydroxylapatite columns by 20mM phosphate (binding protein I) and 200mMphosphate (binding protein II), respectively. 2. The binding protein I is part of a non-histone protein fraction containing acid-soluble and insoluble proteins, whereas the binding protein II elutes together with high molecular weight nonhistone proteins containing acid insoluble proteins only. Both binding proteins exhibit the smae affinity for estradiol (Kd approximately 10(-9) M). 3. From chromatin of untreated chickens very small amounts of binding protein I (0.1 pmol/mg protein compared to 1.9 pmol/mg protein from estrogenized chickens) with the smae affinity for estradiol as that from estrogenized animals can be solubilized. Binding protein II is not detectable. 4. The "soluble nuclear estrogen receptor" extracted from crude liver nucleir of estrogenized chickens by 0.5 M KCL behaves on hydroxylapatite very similarly to salt/urea-dissociated chromatin with respect to the binding protein I. No binding protein II, however, can be demonstrated. 5. Chromatography of various preparations on Bio-Gel A-1.5 m indicates that the binding protein II is a residual chromatin fragment containing an unseparated binding protein-DNA complex, whereas the binding protein I represents the solubilized nucleic-acid-free chromosomal estrogen receptor. The "soluble nuclear receptor" and the binding protein I, however, are not identical with respect to their chromatographic behaviour on Bio-Gel A-1.5m, even though their estrogen binding entity remaining after trypsin treatment seems to be very similar.

  11. Solubilization of pig lymphocyte plasma membrane and fractionation of some of the components

    PubMed Central

    Allan, D.; Crumpton, M. J.

    1971-01-01

    The degree of solubilization of pig lymphocyte plasma membrane by sodium deoxycholate was determined at a variety of temperatures and detergent concentrations. Approx. 95% of the membrane protein was soluble in 2% deoxycholate at 23°C. Some of the biological activities of the membrane survived this treatment. The leucine β-naphthylamidase activity was more readily soluble than the 5′-nucleotidase and these enzymes could be separated by extraction with 0.5% deoxycholate at 0°C. Membrane solubilized in 2% deoxycholate at 23°C was fractionated by sucrose-density-gradient centrifugation in 1% deoxycholate. The phospholipid was separated from the protein, which formed a fairly symmetrical peak that sedimented slightly slower than ovalbumin; the leucine naphthylamidase and 5′-nucleotidase activities were resolved from each other and from the main protein peak. Similar separations were achieved by elution from Sephadex G-200 and Sepharose 6B in 1% deoxycholate. The main proteins, however, appeared to possess much higher molecular weights than those indicated by sucrose-density-gradient centrifugation. This disparity suggests that many of the membrane proteins have a rod-like shape, especially since the results of experiments with [14C]deoxycholate revealed that the proteins did not bind significant amounts of deoxycholate. In contrast, 5′-nucleotidase and leucine naphthylamidase appeared to be globular. Polyacrylamide-gel electrophoresis of membrane solubilized in sodium dodecyl sulphate gave a similar distribution of protein to that achieved by sucrose-density-gradient centrifugation. Trace amounts only of polypeptides of molecular weight less than 10000 were detected. ImagesPLATE 1 PMID:4256533

  12. Binding of (/sup 3/H)forskolin to platelet membranes and solubilized proteins from bovine brain

    SciTech Connect

    Nelson, C.A.; Seamon, K.B.

    1986-05-01

    (/sup 3/H)Forskolin ((/sup 3/H)FSK) bound to platelet membranes with a Kd of 20 nM and a Bmax of 125 fmol/mg protein. The Bmax was increased to 400 fmol/mg protein in the presence of GppNHp (or NaF) and MgCl/sub 2/ with no change in Kd. PGE/sub 1/ decreased the EC50 of GppNHp to increase the Bmax for (/sup 3/H)FSK binding from 600 nM to 35 nM. In contrast, PGE/sub 1/ had no effect on the EC50 of NaF to increase (/sup 3/H)FSK binding. (/sup 3/H)FSK binding increased slowly over 60 min when forskolin and GppNHp were added to membranes simultaneously at 20/sup 0/C. Preincubation of membranes with GppNHp at 20/sup 5/C also caused a linear increase in adenylate cyclase specific activity over 60 minutes. (/sup 3/H)FSK bound to solubilized protein from bovine brain membrane with a Kd of 22 nM. GppNHp increased the number of binding sites in solubilized proteins only if membranes were not preincubated with GppNHp prior to solubilization. In conclusion the number of binding sites for (/sup 3/H)FSK is increased by agents that activate adenylate cyclase through the Ns protein. These sites appear to be associated with an activated complex of the Ns protein and adenylate cyclase.

  13. Reconstitution of hormone-responsive detergent-solubilized follicle stimulating hormone receptors into liposomes

    SciTech Connect

    Grasso, P.; Dattatreyamurty, B.; Reichert, L.E. Jr.

    1988-05-01

    An FSH receptor-enriched fraction that responds to exogenous FSH by activation of adenylate cyclase was prepared by ultrafiltration of sucrose density gradient-purified light membranes derived from bovine calf testes homogenates and solubilized with Triton X-100. To further confirm the functional nature of the detergent-solubilized FSH receptor, the extract was incorporated by lipid hydration into large multilamellar vesicles composed of dioleoyl phosphatidylcholine and cholesterol, 2:1 molar ratio. Receptor incorporation was determined by measurement of specific binding of (125I) human FSH ((125I) hFSH). Substitution of dioleoyl phosphatidylcholine with dipalmitoyl phosphatidylcholine or increasing the cholesterol concentration of the vesicles reduced specific binding of (125I)hFSH. Under conditions favoring optimal incorporation of the receptor, specific binding of (125I)hFSH was time and temperature dependent and saturable when increasing concentrations of radioligand were added to a constant amount of proteoliposomes. Reconstituted proteoliposomes bound 1600 fmol FSH/mg protein with an affinity of 3.54 x 10(9) M-1. Inhibition of (125I) hFSH binding by hFSH was comparable to that seen with the membrane-bound receptor (ED50 = 10 ng). Equilibrium binding studies with (3H)Gpp(NH)p indicated that a single class of high affinity GTP binding sites with an association constant (Ka) of 3.33 x 10(7) m-1 which bound 2.19 fmol (3H)Gpp(NH)p/mg protein had also been incorporated into the proteoliposomes. Addition of FSH induced a 2-fold stimulation of (3H)Gpp(NH)p binding, supporting our earlier studies suggesting that the detergent-solubilized FSH receptor is complexed to the G protein. Of particular significance in the present study was the observation that both NaF and FSH stimulated cAMP production in the reconstituted system.

  14. Application of peptide gemini surfactants as novel solubilization surfactants for photosystems I and II of cyanobacteria.

    PubMed

    Koeda, Shuhei; Umezaki, Katsunari; Noji, Tomoyasu; Ikeda, Atsushi; Kawakami, Keisuke; Kondo, Masaharu; Yamamoto, Yasushi; Shen, Jian-Ren; Taga, Keijiro; Dewa, Takehisa; Ito, Shigeru; Nango, Mamoru; Tanaka, Toshiki; Mizuno, Toshihisa

    2013-09-17

    We designed novel peptide gemini surfactants (PG-surfactants), DKDKC12K and DKDKC12D, which can solubilize Photosystem I (PSI) of Thermosynecoccus elongatus and Photosystem II (PSII) of Thermosynecoccus vulcanus in an aqueous buffer solution. To assess the detailed effects of PG-surfactants on the original supramolecular membrane protein complexes and functions of PSI and PSII, we applied the surfactant exchange method to the isolated PSI and PSII. Spectroscopic properties, light-induced electron transfer activity, and dynamic light scattering measurements showed that PSI and PSII could be solubilized not only with retention of the original supramolecular protein complexes and functions but also without forming aggregates. Furthermore, measurement of the lifetime of light-induced charge-separation state in PSI revealed that both surfactants, especially DKDKC12D, displayed slight improvement against thermal denaturation below 60 °C compared with that using β-DDM. This degree of improvement in thermal resistance still seems low, implying that the peptide moieties did not interact directly with membrane protein surfaces. By conjugating an electron mediator such as methyl viologen (MV(2+)) to DKDKC12K (denoted MV-DKDKC12K), we obtained derivatives that can trap the generated reductive electrons from the light-irradiated PSI. After immobilization onto an indium tin oxide electrode, a cathodic photocurrent from the electrode to the PSI/MV-DKDKC12K conjugate was observed in response to the interval of light irradiation. These findings indicate that the PG-surfactants DKDKC12K and DKDKC12D provide not only a new class of solubilization surfactants but also insights into designing other derivatives that confer new functions on PSI and PSII.

  15. Nanostructures in water-in-CO2 microemulsions stabilized by double-chain fluorocarbon solubilizers.

    PubMed

    Sagisaka, Masanobu; Iwama, Shuho; Ono, Shinji; Yoshizawa, Atsushi; Mohamed, Azmi; Cummings, Stephen; Yan, Ci; James, Craig; Rogers, Sarah E; Heenan, Richard K; Eastoe, Julian

    2013-06-25

    High-pressure small-angle neutron scattering (HP-SANS) studies were conducted to investigate nanostructures and interfacial properties of water-in-supercritical CO2 (W/CO2) microemulsions with double-fluorocarbon-tail anionic surfactants, having different fluorocarbon chain lengths and linking groups (glutarate or succinate). At constant pressure and temperature, the microemulsion aqueous cores were found to swell with an increase in water-to-surfactant ratio, W0, until their solubilizing capacities were reached. Surfactants with fluorocarbon chain lengths of n = 4, 6, and 8 formed spherical reversed micelles in supercritical CO2 even at W0 over the solubilizing powers as determined by phase behavior studies, suggesting formation of Winsor-IV W/CO2 microemulsions and then Winsor-II W/CO2 microemulsions. On the other hand, a short C2 chain fluorocarbon surfactant analogue displayed a transition from Winsor-IV microemulsions to lamellar liquid crystals at W0 = 25. Critical packing parameters and aggregation numbers were calculated by using area per headgroup, shell thickness, the core/shell radii determined from SANS data analysis: these parameters were used to help understand differences in aggregation behavior and solubilizing power in CO2. Increasing the microemulsion water loading led the critical packing parameter to decrease to ~1.3 and the aggregation number to increase to >90. Although these parameters were comparable between glutarate and succinate surfactants with the same fluorocarbon chain, decreasing the fluorocarbon chain length n reduced the critical packing parameter. At the same time, reducing chain length to 2 reduced negative interfacial curvature, favoring planar structures, as demonstrated by generation of lamellar liquid crystal phases.

  16. Cholate-solubilized erythrocyte glucose transporters exist as a mixture of homodimers and homotetramers.

    PubMed

    Hebert, D N; Carruthers, A

    1991-05-14

    The molecular size of purified, human erythrocyte glucose transport protein (GLUT1) solubilized in cholic acid was determined by size-exclusion chromatography (SEC) and sucrose gradient ultracentrifugation. GLUT1 purified in the presence of dithiothreitol (GLUT1 + DTT) is resolved as a complex of average Stokes' radius 5.74 nm by SEC. This complex displays D-glucose-inhibitable cytochalasin B binding and, upon reconstitution into proteoliposomes, catalyzes cytochalasin B inhibitable D-glucose transport. GLUT1 purified in the absence of dithiothreitol (GLUT1-DTT) is resolved by SEC as at least two particles of average Stokes' radii 5.74 (minor component) and 7.48 nm (major component). Solubilization of GLUT1-DTT in the presence of dithiothreitol reduces the amount of 7.48-nm complex and increases the amount of 5.74-nm complex resolved by SEC. GLUT1-DTT displays D-glucose-inhibitable cytochalasin B binding and, upon reconstitution into proteoliposomes, catalyzes cytochalasin B inhibitable D-glucose transport. Sucrose gradient ultracentrifugation of GLUT1 + DTT in cholate resolves GLUT1 into two components of 4.8 and 7.6 S. The 4.8S complex is the major component of GLUT1 + DTT. The reverse profile is observed upon sucrose gradient ultracentrifugation of GLUT1-DTT. SEC of human erythrocyte membrane proteins resolves GLUT1 as a major broad peak of average Stokes' radius 7.48 nm and a minor component of 5.74 nm. Both components are characterized by D-glucose-inhibitable cytochalasin B binding. Purified GLUT1 is associated with approximately 26 tightly bound lipid molecules per monomer of transport protein. These data suggest that purified GLUT1 exists as a mixture of homodimers and homotetramers in cholate-lipid micelles and that the presence of reductant during solubilization favors dimer formation.

  17. A novel solubilization of phenanthrene using Winsor I microemulsion-based sodium castor oil sulfate.

    PubMed

    Zhao, Baowei; Zhu, Lizhong; Gao, Yanzheng

    2005-03-17

    Problems associated with polycyclic aromatic hydrocarbons (PAHs) contaminated site in environmental media have received increasing attention. Ex situ soil washing is commonly used for treating contaminated soils by separating the most contaminated fraction of the soil for disposal. Surfactant-enhanced soil washing is being considered with increasing frequency to actually achieve soil-contaminant separation. In this research, a novel solubilization of phenanthrene and extraction of phenanthrene from spiked soil by sodium castor oil sulfate (SCOS) microemulsion was presented and compared with the conventional surfactants, Triton X-100 (TX100), Tween 80 (TW80), Brij35, sodium dodecylbenzene sulfonate (SDBS) and sodium dodecyl sulfate (SDS). Unlike conventional surfactants, SCOS forms stable microemulsion in water and thus behaves much like a separate bulk phase in concentrating organic solutes. The extent of solubility enhancement is linearly proportional to the concentration of SCOS microemulsion, in contrast with the effect of a conventional surfactant in which a sharp inflection occurs in the vicinity of the measured critical micelle concentration. SCOS microemulsion exhibits the largest mass solubilization ratio among the selected surface active agents (SAAs) in both soil-free system and soil-water system. The partitioning coefficients of phenanthrene between the emulsified phase and the aqueous phase, Kem, is slightly larger than those between the micellar pseudo phase and the aqueous phase, Kmc. The extraction experiments demonstrate high and fast desorption of phenanthrene from spiked soil by SCOS microemulsion perhaps due to its high solubilization capacity compared with the conventional surfactant solutions. The results show that SCOS could be an attractive alternative to synthetic surfactants in ex situ washing for PAH-contaminated soils.

  18. Impact of sediments resuspension on metal solubilization and water quality during recurrent reservoir sluicing management.

    PubMed

    Frémion, Franck; Courtin-Nomade, Alexandra; Bordas, François; Lenain, Jean-François; Jugé, Philippe; Kestens, Tim; Mourier, Brice

    2016-08-15

    In dam contexts, sluicing operations can be performed to reestablish sediments continuity, as proposed by the EU Water Framework Directive, as well as to preserve the reservoirs' water storage capacity. Such management permits the rapid release of high quantities of reservoir sediments through the opening of dam bottom valves. This work aims to study the impact of such operation on the evolution of environmental physicochemical conditions notably changes in dissolved metallic elements concentrations (Al, As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn) through field and laboratory investigations. Results were interpreted in terms of concentrations and fluxes, and compared with data collected on an annual basis regarding both suspended matter and metallic elements. The release of high quantities of sediments (4,500tons dry weight in 24h), with concentrations representing up to 300 times the inter-annual mean suspended sediments discharge, significantly modified water parameters, notably solid/liquid (S/L) ratio, pH and redox conditions. Despite the fact that they are mainly trapped in stable phases, a clear increase of the solubilized metals content was measured, representing up to 60 times the maximum values of current exploitation. This solubilization is related to desorption phenomena from sediments through changes in chemical equilibriums as highlighted by laboratory characterizations and experiments. These chemical modifications are mainly attributed to S/L ratio variations. Indeed, the low S/L ratios (≤1.3g·L(-1)) measured in situ are typically the ones for which metals solubilization is the highest, as shown by laboratory experiments. Additional thermodynamic modeling highlighted that the decrease in pH measured during the operation favors the release of the free forms of metallic elements (Al and Cu), and decreases the OM complexation influence. These changes, either in term of physical conditions or speciation, increasing metals long term bioavailability notably

  19. Efficient solubilization and purification of the gastric H+, K+-ATPase for functional and structural studies.

    PubMed Central

    Lacapère, J J; Robert, J C; Thomas-Soumarmon, A

    2000-01-01

    When gastric H(+),K(+)-ATPase-containing microsomes are solubilized by detergents, a rapid loss of ATPase activity is generally observed. In this article, SDS/PAGE of octa(ethylene glycol)dodecyl monoether (C(12)E(8))- and n-dodecyl beta-d-maltoside-solubilized microsomes and their purifications by affinity chromatography on Reactive Red column reveal that inactivation is due to two main effects. (i) Solubilization activates an aspartic protease that cleaves down the alpha-subunit of the H(+),K(+)-ATPase. Addition of pepstatin A at slightly acidic pH and at low temperature prevents the proteolysis. (ii) A too-harsh delipidation inactivates the ATPase. When n-dodecyl-beta-d-maltoside is the detergent, the soluble H(+), K(+)-ATPase is highly active (2.5 micromol/mg per h at pH 6.0 and 5 degrees C) as long as ATP is added. When C(12)E(8) is used, the detergent induces an inactivation due to delipidation, since addition of lipids restores activity. The two subunits of the H(+), K(+)-ATPase are present in equimolar ratio in the n-dodecyl beta-d-maltoside-purified complex. Moreover, two main types of complex (330 and 660 kDa) were resolved in non-denaturing gels and should be the dimeric (alphabeta)(2) and tetrameric (alphabeta)(4) heterodimers respectively. In conclusion, purification of active, stable, soluble complexes of H(+),K(+)-ATPase with few lipids (a lipid/protein ratio of 0.25, w/w) has been achieved. This material should be useful for further structural studies. PMID:10620500

  20. Study of microbial community and biodegradation efficiency for single- and two-phase anaerobic co-digestion of brown water and food waste.

    PubMed

    Lim, J W; Chen, C-L; Ho, I J R; Wang, J-Y

    2013-11-01

    The objective of this work was to study the microbial community and reactor performance for the anaerobic co-digestion of brown water and food waste in single- and two-phase continuously stirred tank reactors (CSTRs). Bacterial and archaeal communities were analyzed after 150 days of reactor operation. As compared to single-phase CSTR, methane production in two-phase CSTR was found to be 23% higher. This was likely due to greater extent of solubilization and acidification observed in the latter. These findings could be attributed to the predominance of Firmicutes and greater bacterial diversity in two-phase CSTR, and the lack of Firmicutes in single-phase CSTR. Methanosaeta was predominant in both CSTRs and this correlated to low levels of acetate in their effluent. Insights gained from this study would enhance the understanding of microorganisms involved in co-digestion of brown water and food waste as well as the complex biochemical interactions promoting digester stability and performance.

  1. Specific immunization of mice against Leishmania mexicana amazonensis using solubilized promastigotes

    NASA Technical Reports Server (NTRS)

    Barral-Netto, M.; Sadigursky, M.; Reed, S. G.; Sonnenfeld, G.

    1987-01-01

    In this work, it was demonstrated that mice (BALB/c strain) highly susceptible to Leishmania mexicana amazonensis can be protected against infection by this parasite by being preimmunized with whole solubilized (in a buffer that contained EDTA, NP-40, and SDS) promastigotes; the use of adjuvant or intact inactivated parasite cells is shown to be not necessary. The best immunization schedule consisted of three intravenous injections of 5 x 10 to the 7th parasite equivalents, administered one to eight weeks before infection. Immunized mice exhibited a marked inhibition of primary lesion development, reduced numbers of parasites in the spleen, and reduced death rate.

  2. Effect of glycoamphiphiles on the solubilization and dendritic cell uptake of a lipopeptide: a preliminary study.

    PubMed

    Bonnet, Dominique; Angyalosi, Gerhild; Demory, Alexandra; Santraine, Valérie; Boulet, Arnaud; Spriet, Corentin; Héliot, Laurent; Gras-Masse, Hélène; Grandjean, Cyrille

    2005-01-01

    The selective delivery of antigens to professional antigen-presenting cells represents a promising approach to improve vaccine efficacy. Addition of a glycoamphiphile to a lipopeptide, whose interest for vaccination is now well-established, greatly favors its solubilization in aqueous solutions through the formation of mixed vesicles. Flow cytometry experiments indicate that this formulation does not diminish the uptake of the lipopeptide by the dendritic cells (DCs). These preliminary results suggest a possible straightforward, noncovalent targeting of cocktail-lipopeptide vaccines to the DCs via carbohydrate receptor-mediated endocytosis.

  3. Biological lignocellulose solubilization: Comparative evaluation of biocatalysts and enhancement via cotreatment

    DOE PAGES

    Paye, Julie M. D.; Guseva, Anna; Hammer, Sarah K.; ...

    2016-01-12

    Feedstock recalcitrance is the most important barrier impeding cost-effective production of cellulosic biofuels. Pioneer commercial cellulosic ethanol facilities employ thermochemical pretreatment and addition of fungal cellulase, reflecting the main research emphasis in the field. However, it has been suggested that it may be possible to process cellulosic biomass without thermochemical pretreatment using thermophilic, cellulolytic bacteria. Thus, to further explore this idea, we examine the ability of various biocatalysts to solubilize autoclaved but otherwise unpretreated cellulosic biomass under controlled but not industrial conditions.

  4. Solubilization and functionalization of sulfuric acid lignin generated during bioethanol production from woody biomass.

    PubMed

    Matsushita, Yasuyuki; Inomata, Toyoki; Hasegawa, Tatsuya; Fukushima, Kazuhiko

    2009-01-01

    Sulfuric acid lignin (SAL), which is formed as a by-product during the production of bioethanol from woody biomass, was solubilized and functionalized by hydrothermal reaction. SAL could be easily dissolved in an alkaline medium, especially sodium hydroxide solution, by this reaction. The soluble part of the reaction products (S-HSAL) could be dissolved at neutral pH. IR spectrometric analysis of SAL revealed that hydrophilic groups were introduced in it during the reaction. The dispersibility of S-HSAL was increased by sulfonation (SS-HSAL), and it was found to be an effective dispersant for gypsum paste.

  5. Solubilization of water in water-in-oil microemulsions of kerosene

    SciTech Connect

    Andheria, A.P.; Bhagwat, S.S.

    1995-04-01

    The incorporation of water into fuels formulated as microemulsions can offer several advantages such as fire resistance, increased flash point, and improved air-fuel contact. To this end, phase equilibria of kerosene microemulsions employing ionic and nonionic surfactants such as sodium di-(2-ethylhexyl) sulfosuccinate (AOT), lauryl diethanolamide (LDEA), nonylphenol EO-4.5 (NPEO-4.5), sorbitan monolaurate (Span-20), and cetyltrimethylammonium bromide (CTAB), as well as cosurfactants such as n-pentanol, n-hexanol, and n-heptanol, were studied. The effect of the aromaticity of the oil phase on the solubilization of water was also investigated.

  6. Microfluidics and microbial engineering.

    PubMed

    Kou, Songzi; Cheng, Danhui; Sun, Fei; Hsing, I-Ming

    2016-02-07

    The combination of microbial engineering and microfluidics is synergistic in nature. For example, microfluidics is benefiting from the outcome of microbial engineering and many reported point-of-care microfluidic devices employ engineered microbes as functional parts for the microsystems. In addition, microbial engineering is facilitated by various microfluidic techniques, due to their inherent strength in high-throughput screening and miniaturization. In this review article, we firstly examine the applications of engineered microbes for toxicity detection, biosensing, and motion generation in microfluidic platforms. Secondly, we look into how microfluidic technologies facilitate the upstream and downstream processes of microbial engineering, including DNA recombination, transformation, target microbe selection, mutant characterization, and microbial function analysis. Thirdly, we highlight an emerging concept in microbial engineering, namely, microbial consortium engineering, where the behavior of a multicultural microbial community rather than that of a single cell/species is delineated. Integrating the disciplines of microfluidics and microbial engineering opens up many new opportunities, for example in diagnostics, engineering of microbial motors, development of portable devices for genetics, high throughput characterization of genetic mutants, isolation and identification of rare/unculturable microbial species, single-cell analysis with high spatio-temporal resolution, and exploration of natural microbial communities.

  7. High pH solubilization and chromatography-based renaturation and purification of recombinant human granulocyte colony-stimulating factor from inclusion bodies.

    PubMed

    Li, Ming; Fan, Hua; Liu, Jiahua; Wang, Minhong; Wang, Lili; Wang, Chaozhan

    2012-03-01

    Recombinant human granulocyte colony-stimulating factor (rhG-CSF) is a very efficient therapeutic protein drug which has been widely used in human clinics to treat cancer patients suffering from chemotherapy-induced neutropenia. In this study, rhG-CSF was solubilized from inclusion bodies by using a high-pH solution containing low concentration of urea. It was found that solubilization of the rhG-CSF inclusion bodies greatly depended on the buffer pH employed; alkalic pH significantly favored the solubilization. In addition, when small amount of urea was added to the solution at high pH, the solubilization was further enhanced. After solubilization, the rhG-CSF was renatured with simultaneous purification by using weak anion exchange, strong anion exchange, and hydrophobic interaction chromatography, separately. The results indicated that the rhG-CSF solubilized by the high-pH solution containing low concentration of urea had much higher mass recovery than the one solubilized by 8 M urea when using anyone of the three refolding methods employed in this work. In the case of weak anion exchange chromatography, the high pH solubilized rhG-CSF could get a mass recovery of 73%. The strategy of combining solubilization of inclusion bodies at high pH with refolding of protein using liquid chromatography may become a routine method for protein production from inclusion bodies.

  8. Pseudomonas corrugata (NRRL B-30409) Mutants Increased Phosphate Solubilization, Organic Acid Production, and Plant Growth at Lower Temperatures.

    PubMed

    Trivedi, Pankaj; Sa, Tongmin

    2008-02-01

    A study for screening and selection of mutants of Pseudomonas corrugata (NRRL B-30409) based on their phosphate solubilization ability, production of organic acids, and subsequent effect on plant growth at lower temperatures under in vitro and in situ conditions was conducted. Of a total 115 mutants tested, two (PCM-56 and PCM-82) were selected based on their greater phosphate solubilization ability at 21 degrees C in Pikovskaya's broth. The two mutants were found more efficient than wild-type strain for phosphate solubilization activity across a range of temperature from psychotropic (4 degrees C) to mesophilic (28 degrees C) in aerated GPS medium containing insoluble rock phosphate. High-performance liquid chromatography analysis showed that phosphate solubilization potential of wild-type and mutant strains were mediated by production of organic acids in the culture medium. The two efficient mutants and the wild strain oxidized glucose to gluconic acid and sequentially to 2-ketogluconic acid. Under in vitro conditions at 10 degrees C, the mutants exhibited increased plant growth as compared to wild type, indicating their functionality at lower temperatures. In greenhouse trials using sterilized soil amended with either soluble or rock phosphate, inoculation with mutants showed greater positive effect on all of the growth parameters and soil enzymatic activities. To the best of our knowledge, this is the first report on the development of phosphate solubilizing mutants of psychotropic wild strain of P. corrugata, native to the Indian Himalayan region.

  9. Solubilization of menthol by platycodin D in aqueous solution: an integrated study of classical experiments and dissipative particle dynamics simulation.

    PubMed

    Ding, Haiou; Yin, Qianqian; Wan, Guang; Dai, Xingxing; Shi, Xinyuan; Qiao, Yanjiang

    2015-03-01

    Menthol (M) and platycodin D (PD) are the main active ingredients in Mentha haplocalyx and Platycodon grandiflorum A. DC., respectively. They are commonly used in combination in traditional Chinese medicine. In this study, laboratory experiments and computer simulations were used to investigate the solubilization of M by PD, which was believed to be one of the main causes of the synergistic effect of M. haplocalyx and P. grandiflorum A. DC. Results showed that both the method by which M was added and the concentration of PD had significant effects on the solubilization efficiency of M, and these influences were closely associated with each other. Temperature, an important environmental condition, was also found to have a significant effect on the solubilization effect of PD. These findings not only clarify the molecular basis of the solubilization effect, including amount solubilized at the macroscale and the structures of the micelles, and the drug loading mechanisms and processing at the mesoscale. This work may provide some guidance for the further development of saponins and fundamental research in the drug delivery system.

  10. Preferential solubilization behaviours and stability of some phenolic-bearing essential oils formulated in different microemulsion systems.

    PubMed

    Edris, A E; Malone, C F R

    2012-10-01

    The solubilization behaviour of a number of essential oils (EOs) containing volatile phenolic constituents was investigated in five different micellar solutions. These oils include clove bud (Eugenia caryophyllata), thyme (Thymus serpyllum) and oregano (Thymus capitatus). Ternary and pseudo-ternary phase diagrams were constructed to assess the ability for microemulsion formation and dilutability of each system using non-ionic surfactants. Results showed that Tween 20 (T20) was more suitable to solubilize these oils compared with Tween 80 (T80). Clove EO was found to be easily microemulsifiable compared with the other EOs, whereas oregano showed the least tendency to form a microemulsion. Particle sizes measured at different dilution lines ranged between 5.9 and 16.9 nm. The chemical composition of each EO was revealed by gas chromatography and was correlated with the observed solubilization behaviour. The presence of solubilization enhancers like poly-ols and short-chain alcohols improved solubilization of all EOs; however, establishment of new dilution lines was controlled by EO type. Physical stability assessment showed that all microemulsions were stable against alternate freeze/thaw cycles which extended for 1 week. On the contrary, each system showed different temperature sensitivity in the thermal stress assessment. The results of this investigation can be useful in fabrication of thermodynamically stable aqueous system carrying aromatic and bioactive phenolics for different applications in personal hygiene, cosmetic, fragrance and pharmaceutical products.

  11. Effect of synthetic surfactants on the solubilization and distribution of PAHs in water/soil-water systems.

    PubMed

    Cheng, K Y; Wong, J W C

    2006-08-01

    The present study examined the effects of four surfactants, including three non-ionic surfactants (Tween 80, Triton X-100 and Brij 35) and an anionic surfactant SDS on the solubilization and distribution of phenanthrene (Phe) and pyrene (Pyr) in soil-water systems. All four surfactants could enhance the solubilization of Phe and Pyr in aqueous phase linearly when surfactant concentrations exceeded their respective critical micelle concentrations (CMC). Molar solubilization ratio (MSR) which indicated surfactant's solubilization capacity for Phe and Pyr, was highest for Tween 80 for both PAHs, and SDS had the lowest among the four surfactants, while Triton X-100 and Brij 35 had about the same MSR for both PAHs. Moreover, all the surfactants could provide a strong micelle partitioning phase for the more hydrophobic Pyr than Phe as revealed by their high micelle--aqueous phase partition coefficient, K(mc). Batch desorption studies also demonstrated that Tween 80 had the best capacity for the desorption of both Phe and Pyr in the soil-water systems, and followed by Triton X-100 and Brij 35, while SDS seems to have no positive effect on the desorption of PAHs probably due to its relatively high CMC value. Therefore, from the application standpoint, the results obtained in this study suggest that Tween 80 would be the most suitable candidate among the four surfactants in improving solubilization and desorption of PAHs in soil-water system, which are believed to be the prerequisites for successful bioremediation technology for PAH contaminated soil.

  12. Lignin solubilization and aqueous phase reforming for the production of aromatic chemicals and hydrogen.

    PubMed

    Zakzeski, Joseph; Weckhuysen, Bert M

    2011-03-21

    The solubilization and aqueous phase reforming of lignin, including kraft, soda, and alcell lignin along with sugarcane bagasse, at low temperatures (T≤498 K) and pressures (P≤29 bar) is reported for the first time for the production of aromatic chemicals and hydrogen. Analysis of lignin model compounds and the distribution of products obtained during the lignin aqueous phase reforming revealed that lignin was depolymerized through disruption of the abundant β-O-4 linkages and, to a lesser extent, the 5-5' carbon-carbon linkages to form monomeric aromatic compounds. The alkyl chains contained on these monomeric compounds were readily reformed to produce hydrogen and simple aromatic platform chemicals, particularly guaiacol and syringol, with the distribution of each depending on the lignin source. The methoxy groups present on the aromatic rings were subject to hydrolysis to form methanol, which was also readily reformed to produce hydrogen and carbon dioxide. The composition of the isolated yields of monomeric aromatic compounds and overall lignin conversion based on these isolated yields varied from 10-15% depending on the lignin sample, with the balance consisting of gaseous products and residual solid material. Furthermore, we introduce the use of a high-pressure autoclave with optical windows and an autoclave with ATR-IR sentinel for on-line in situ spectroscopic monitoring of biomass conversion processes, which provides direct insight into, for example, the solubilization process and aqueous phase reforming reaction of lignin.

  13. In vivo behavior of detergent-solubilized purified rabbit thrombomodulin on intravenous injection into rabbits

    SciTech Connect

    Ehrlich, H.J.; Esmon, N.L.; Bang, N.U. )

    1990-02-01

    Thrombomodulin is a thrombin endothelial cell membrane receptor. The thrombomodulin-thrombin complex rapidly activates protein C resulting in anticoagulant activity. We investigated the anticoagulant effects and pharmacokinetic behavior of detergent-solubilized purified rabbit thrombomodulin labeled with iodine 125 when intravenously injected into rabbits. Thrombomodulin half-life (t1/2) was determined by tracking the 125I-radiolabeled protein and the biologic activity as determined by the prolongation of the activated partial thromboplastin time (APTT) and thrombin clotting time (TCT). When 200 micrograms/kg 125I-thrombomodulin was injected into rabbits, the APTT and TCT were immediately prolonged, whereas no effect on the prothrombin time was seen. In vitro calibration curves enabled us to convert the prolongations of the clotting times into micrograms per milliliter thrombomodulin equivalents. The best fit (r greater than 0.99) for the disappearance curves was provided by a two-compartment model with mean t1/2 alpha (distribution phase) of 18 minutes for 125I, 12 minutes for APTT, and 20 minutes for TCT, and mean t1/2 beta (elimination phase) of 385 minutes for 125I, 460 for APTT, and 179 for TCT. The administration of two doses of endotoxin (50 micrograms/kg) 24 hours apart did not accelerate the turnover rate of 125I-thrombomodulin as measured by the disappearance of 125I from the circulation. Thus, detergent-solubilized purified thrombomodulin administered intravenously circulates in a biologically active form for appreciable time periods.

  14. Rapid directed evolution of stabilized proteins with cellular high-throughput encapsulation solubilization and screening (CHESS).

    PubMed

    Yong, K J; Scott, D J

    2015-03-01

    Directed evolution is a powerful method for engineering proteins towards user-defined goals and has been used to generate novel proteins for industrial processes, biological research and drug discovery. Typical directed evolution techniques include cellular display, phage display, ribosome display and water-in-oil compartmentalization, all of which physically link individual members of diverse gene libraries to their translated proteins. This allows the screening or selection for a desired protein function and subsequent isolation of the encoding gene from diverse populations. For biotechnological and industrial applications there is a need to engineer proteins that are functional under conditions that are not compatible with these techniques, such as high temperatures and harsh detergents. Cellular High-throughput Encapsulation Solubilization and Screening (CHESS), is a directed evolution method originally developed to engineer detergent-stable G proteins-coupled receptors (GPCRs) for structural biology. With CHESS, library-transformed bacterial cells are encapsulated in detergent-resistant polymers to form capsules, which serve to contain mutant genes and their encoded proteins upon detergent mediated solubilization of cell membranes. Populations of capsules can be screened like single cells to enable rapid isolation of genes encoding detergent-stable protein mutants. To demonstrate the general applicability of CHESS to other proteins, we have characterized the stability and permeability of CHESS microcapsules and employed CHESS to generate thermostable, sodium dodecyl sulfate (SDS) resistant green fluorescent protein (GFP) mutants, the first soluble proteins to be engineered using CHESS.

  15. Membrane solubilization in erythrocytes as a measure of radiation exposure to fast neutrons

    NASA Astrophysics Data System (ADS)

    Soltan Monem, A.; Ali, Fadel M.; Al-thani, Noura J. J.; Ali, Samira A.

    1999-02-01

    Membrane solubilization and osmotic fragility of rat erythrocytes irradiated in vivo with fast neutron fluences ranging from to using a source were measured instantaneously using a light scattering technique. The solubilization of erythrocyte membrane by a non-ionic detergent, octylglucoside (OG), was found to exhibit a two stage transition from vesicular form to mixed micellar form in the range of detergent concentrations 1.5-7.8 mM. The coexistence phase, vesicular/mixed micellar, was shifted towards higher detergent concentrations with increase in the neutron fluence, indicating increasing membrane resistance to the detergent and hence change in the natural membrane permeation properties. The technique shows an adequate sensitivity in detecting membrane damage in erythrocytes and has potential as a biophysical marker of radiation exposure. The osmotic fragility of irradiated erythrocytes shows a decreasing trend with increasing irradiation fluence measured directly and two weeks post-irradiation. Blood films photographed two weeks post-irradiation show developed elliptocytosis and crenated cell anaemia.

  16. Effect of cations on the solubilization/deposition of triclosan in sediment-water-rhamnolipid system.

    PubMed

    Chen, Yuanbo; Hu, Yongyou; Guo, Qian; Yan, Jia; Wu, Wenjin

    2016-09-01

    Cations had great influence on the self-assembly of rhamnolipid, which in turn affected the fate of triclosan. The migration of triclosan from sediment to water benefited its biodegradation but it could be transformed into more toxic compounds. To regulate the fate of triclosan and reduce environmental risks extremely, the effect of four common cations in surface water (Na(+)/K(+)/Ca(2+)/Mg(2+)) on the solubilization/deposition of triclosan in sediment-water-rhamnolipid system was investigated. The interaction among cations, triclosan and rhamnolipid was explored based on self-assembly of rhamnolipid and water solubility of triclosan in rhamnolipid solutions. Results showed that cations had little influence on the fate of triclosan in the absence of rhamnolipid. Cations, especially Ca(2+)/Mg(2+), reduced the critical micelle concentration, micellar size and zeta potential of rhamnolipid solutions. The changes in self-assembly of rhamnolipid with different cations led to the difference of residual rhamnolipid concentration in water, which was nearly invariant with 0.01 M Na(+)/K(+) while decreased significantly with 0.01 M Ca(2+)/Mg(2+). Consequently, water solubility of triclosan in rhamnolipid solutions increased with the addition of Na(+)/K(+) whereas decreased with Ca(2+)/Mg(2+). In sediment-water- rhamnolipid system, triclosan was slightly solubilized from sediment to water with Na(+)/K(+) while deposited in sediment with Ca(2+)/Mg(2+). These findings provided an alternative application of rhamnolipid for the remediation of triclosan-polluted sediment.

  17. High-resolution crystal structures of the solubilized domain of porcine cytochrome b{sub 5}

    SciTech Connect

    Hirano, Yu; Kimura, Shigenobu; Tamada, Taro

    2015-06-30

    Crystal structures of the solubilized domain of cytochrome b{sub 5} from porcine liver were determined at sub-angstrom resolution in two crystal forms for both the oxidized and reduced states. The high-resolution structures provided information about the factors that are important for regulating the electronic properties of the haem group of cytochrome b{sub 5}. Mammalian microsomal cytochrome b{sub 5} has multiple electron-transfer partners that function in various electron-transfer reactions. Four crystal structures of the solubilized haem-binding domain of cytochrome b{sub 5} from porcine liver were determined at sub-angstrom resolution (0.76–0.95 Å) in two crystal forms for both the oxidized and reduced states. The high-resolution structures clearly displayed the electron density of H atoms in some amino-acid residues. Unrestrained refinement of bond lengths revealed that the protonation states of the haem propionate group may be involved in regulation of the haem redox properties. The haem Fe coordination geometry did not show significant differences between the oxidized and reduced structures. However, structural differences between the oxidized and reduced states were observed in the hydrogen-bond network around the axial ligand His68. The hydrogen-bond network could be involved in regulating the redox states of the haem group.

  18. Rate of carotenoid triplet formation in solubilized light-harvesting complex II (LHCII) from spinach.

    PubMed Central

    Schödel, R; Irrgang, K D; Voigt, J; Renger, G

    1998-01-01

    In the present study the rate of triplet transfer from chlorophyll to carotenoids in solubilized LHCII was investigated by flash spectroscopy using laser pulses of approximately 2 ns for both pump and probe. Special attention has been paid to calibration of the experimental setup and to avoid saturation effects. Carotenoid triplets were identified by the pronounced positive peak at approximately 507 nm in the triplet-singlet difference spectra. DeltaOD (507 nm) exhibits a monoexponential relaxation kinetics with characteristic lifetimes of 2-9 micros (depending on the oxygen content) that was found to be independent of the pump pulse intensity. The rise of DeltaOD (507 nm) was resolved via a pump probe technique where an optical delay of up to 20 ns was used. A thorough analysis of these experimental data leads to the conclusion that the kinetics of carotenoid triplet formation in solubilized LHCII is almost entirely limited by the lifetime of the excited singlet state of chlorophyll but neither by the pulse width nor by the rate constant of triplet-triplet transfer. Within the experimental error the rate constant of triplet-triplet transfer from chlorophyll to carotenoids was estimated to be kTT > (0.5 ns)-1. This value exceeds all data reported so far by at least one order of magnitude. The implications of this finding are briefly discussed. PMID:9826635

  19. Animal Bones Char Solubilization by Gel-Entrapped Yarrowia lipolytica on Glycerol-Based Media

    PubMed Central

    Vassileva, Maria; Eichler-Lobermann, Bettina; Reyes, Antonia; Vassilev, Nikolay

    2012-01-01

    Citric acid was produced with free and k-carrageenan-entrapped cells of the yeast Yarrowia lipolytica in single and repeated batch-shake-flask fermentations on glycerol-based media. Simultaneous solubilization of hydroxyapatite of animal bone origin (HABO) was tested in all experiments. The highest citric acid production by free yeast cells of 20.4 g/L and 18.7 g/L was reached after 96 h of fermentation in the absence and presence of 3 g/L HABO, respectively. The maximum values for the same parameter achieved by gel-entrapped cells in conditions of single batch and repeated-batch fermentation processes were 18.7 g/L and 28.1 g/L registered after 96 h and the 3d batch cycle, respectively. The highest citric acid productivity of 0.58 g L−1 h−1 was obtained with immobilized cells in repeated batch mode of fermentation when the added hydroxyapatite of 3 g/L was solubilized to 399 mg/L whereas the maximum efficiency of 89.0% was obtained with 1 g/L of HABO. PMID:22645462

  20. The Effective Solubilization of Hydrophobic Drugs Using Epigallocatechin Gallate or Tannic Acid-Based Formulations.

    PubMed

    Jackson, John K; Letchford, Kevin

    2016-10-01

    Hydrotropic solubilization of hydrophobic drugs requires supramolar amounts of hydrotropes with potential toxicity issues. We investigated the use of epigallocatechin gallate (EGCG) and tannic acid at millimolar concentrations, as hydrotrope-like solubilizing agents. Paclitaxel, docetaxel, amphotherecin B, curcumin, or rapamycin were dried down with EGCG or tannic acid from ethanol and then redissolved in aqueous media. Following centrifugation and filtration, the drug solubility was measured using HPLC. The uptake of docetaxel into cells from EGCG-based solutions was measured using radiolabeled drugs. Both EGCG and tannic acid effectively increased the aqueous solubility of all drugs from low levels (μg/mL) to high levels (mg/mL) in a concentration-dependent fashion at millimolar concentrations. Solutions were generally stable at room temperature over 24 h. Compared with micellar formulations, EGCG-based solutions of docetaxel demonstrated markedly improved drug uptake or transport levels in all cell lines. The use of these additives may provide improved formulation of various hydrophobic drugs using oral, parenteral, localized, or device-associated delivery systems.

  1. Supramolecular aggregates of water soluble dendritic polyglycerol architectures for the solubilization of hydrophobic compounds.

    PubMed

    Kurniasih, Indah N; Liang, Hua; Rabe, Jürgen P; Haag, Rainer

    2010-09-01

    Dendritic core-shell architectures which are based on hyperbranched polyglycerol for the solubilization of hydrophobic drugs have been synthesized and characterized. The core of hyperbranched polyglycerol has been modified with hydrophobic biphenyl groups or perfluorinated chains to increase the core hydrophobicity of the macromolecules. These amphiphilic core-shell type architectures were then used to solubilize pyrene, nile red, and a perfluoro tagged diazo dye, as well as the drug nimodipine in water. Specific host-guest interactions such as fluorous-fluorous interactions could be tailored by this flexible core design and determined by UV spectroscopy. The transport capacity increased 450-fold for nile red, 47-fold for nimodipine, and 37-fold for pyrene at a polymer concentration of only 0.1 wt.-%. Surface tension measurements and scanning force microscopy (SFM) were used to reveal the aggregation properties of these complexes. The formation of supramolecular aggregates with diameters of ≈20 nm and critical aggregate concentrations of 2 × 10(-6)  mol · L(-1) have been observed. This indicates the controlled self-assembly of the presented amphiphilic dendritic core-shell type architectures.

  2. Restitution of infectivity to spikeless vesicular stomatitis virus by solubilized viral components.

    PubMed

    Bishop, D H; Repik, P; Obijeski, J F; Moore, N F; Wagner, R R

    1975-07-01

    Noninfectious spikeless particles have been obtained from vesicular stomatitis virus (VSV, Indiana serotype) by bromelain or Pronase treatment. They lack the viral glycoprotein (G) but contain all the other viral components (RNA, lipid, and other structural proteins). Triton-solubilized VSV-Indiana glycoprotein preparations, containing the viral G protein as well as lipids (including phospholipids), have been extracted from whole virus preparations, freed from the majority of the detergent, and used to restore infectivity to spikeless VSV. The infectivity of such particles has been found to be enhanced by poly-L-ornithine but inhibited by Trition or homologous antiserum pretreatment. Heat-denatured glycoprotein preparations were not effective in restoring the infectivity to spikeless VSV. Heterologous glycoprotein preparations from the serologically distinct VSV-New Jersey serotype were equally capable of making infectious entities with VSV-Indiana spikeless particles, and the infectivity of these structures was inhibited by VSV-New Jersey antiserum but not by VSV-Indiana antiserum. Purified, detergent-free glycoprotein selectively solubilized from VSV-Indiana by the dialyzable detergent, octylglucoside, also restored infectivity of spikeless virions of VSV-Indiana and VSV-New Jersey.

  3. Permeability assessment of poorly water-soluble compounds under solubilizing conditions: the reciprocal permeability approach.

    PubMed

    Katneni, Kasiram; Charman, Susan A; Porter, Christopher J H

    2006-10-01

    The objective of this study was to develop a general method to assess the intestinal permeability of poorly water-soluble drugs where low-aqueous drug solubility requires conduct of experiments under solubilizing experimental conditions. The permeability (Papp) of diazepam (DIA) was assessed across excised rat jejunum in the absence (Pappcontrol) and presence (Pappuncorr) of polysorbate-80 (PS-80). The micellar association constant (Ka) of DIA, estimated via equilibrium solubility studies, was used to correct Pappuncorr data and obtain an estimate of the true permeability coefficient (Pappcorr). An alternate approach was also developed (the reciprocal permeability approach) to allow direct estimation of Pappcorr without the need for independent estimation of Ka. The approach was further examined experimentally using a range of model drugs. DIA Pappcorr values obtained using the Ka from equilibrium solubility studies deviated from Papp(control) values, especially at PS-80 concentrations above 0.1% w/v. In contrast, data obtained using the reciprocal permeability method were consistent with Pappcontrol across the PS-80 concentration range. Similar trends were observed with propranolol (PRO), antipyrine (ANT), naproxen (NAP), and cinnarizine (CIN). The reciprocal permeability approach therefore provides a simple and accurate method by which the permeability of poorly water-soluble compounds may be estimated under solubilizing conditions.

  4. Enhancing radium solubilization in soils by citrate, EDTA, and EDDS chelating amendments.

    PubMed

    Prieto, C; Lozano, J C; Blanco Rodríguez, P; Tomé, F Vera

    2013-04-15

    The effect of three chelating agents (citrate, EDTA, and EDDS) on the solubilization of radium from a granitic soil was studied systematically, considering different soil pH values, chelating agent concentrations, and leaching times. For all the chelating agents tested, the amount of radium leached proved to be strongly dependent on the pH of the substrate: only for acidic conditions did the amount of radium released increase significantly relative to the controls. Under the best conditions, the radium released from the amended soil was greater by factors of 20 in the case of citrate, 18 for EDTA, and 14 for EDDS. The greatest improvement in the release of radium was obtained for the citrate amendment at the highest concentration tested (50 mmol kg(-1)). A slightly lower amount of radium was leached with EDTA at 5 mmol kg(-1) soil, but the solubilization over time was very different from that observed with citrate or EDDS. With EDTA, a maximum in radium leaching was reached on the first day after amendment, while with citrate, the maximum was attained on the fourth day. With EDDS, radium leaching increased slightly but steadily with time (until the sixth day), but the net effect for the period tested was the lowest of the three reagents.

  5. Mechanistic Analysis of Cocrystal Dissolution as a Function of pH and Micellar Solubilization

    PubMed Central

    2016-01-01

    The purpose of this work is to provide a mechanistic understanding of the dissolution behavior of cocrystals under the influence of ionization and micellar solubilization. Mass transport models were developed by applying Fick’s law of diffusion to dissolution with simultaneous chemical reactions in the hydrodynamic boundary layer adjacent to the dissolving cocrystal surface to predict the pH at the dissolving solid–liquid interface (i.e., interfacial pH) and the flux of cocrystals. To evaluate the predictive power of these models, dissolution studies of carbamazepine–saccharin (CBZ-SAC) and carbamazepine–salicylic acid (CBZ-SLC) cocrystals were performed at varied pH and surfactant concentrations above the critical stabilization concentration (CSC), where the cocrystals were thermodynamically stable. The findings in this work demonstrate that the pH dependent dissolution behavior of cocrystals with ionizable components is dependent on interfacial pH. This mass transport analysis demonstrates the importance of pH, cocrystal solubility, diffusivity, and micellar solubilization on the dissolution rates of cocrystals. PMID:26877267

  6. Solubilization and reconstitution of the oat root vacuole H sup + /Ca sup 2+ exchanger

    SciTech Connect

    Schumaker, K.S.; Sze, H. )

    1990-02-01

    Calcium is sequestered into vacuoles of oat (Avena sativa L.) root cells via a H{sup +}/Ca{sup 2+} antiporter, and vesicles derived from the vacuolar membrane (tonoplast) catalyze an uptake of calcium which is dependent on protons (pH gradient ({Delta}pH) dependent). The first step toward purification and identification of the H{sup +}/Ca{sup 2+} antiporter is to solubilize and reconstitute the transport activity in liposomes. The vacuolar H{sup +}/Ca{sup 2+} antiporter was solubilized with octylglucoside in the presence of soybean phospholipids and glycerol. After centrifugation, the soluble proteins were reconstituted into liposomes by detergent dilution. A {Delta}pH (acid inside) was generated in the proteoliposomes with an NH{sub 4}Cl gradient (NH{sub 4}{sup +}{sub in} {much gt} NH{sub 4}{sup +}{sub out}) as determined by methylamine uptake. Fundamental properties of {Delta}pH dependent calcium uptake such as the K{sub m} for calcium ({approximately}15 micromolar) and the sensitivity to inhibitors such as N,N{prime}-dicyclohexylcarbodiimide, ruthenium red, and lanthanum, were similar to those found in membrane vesicles, indicating that the H{sup +}/Ca{sup 2+} antiporter has been reconstituted in active form.

  7. Membrane solubilization by a hydrophobic polyelectrolyte: surface activity and membrane binding.

    PubMed Central

    Thomas, J L; Barton, S W; Tirrell, D A

    1994-01-01

    We have previously observed that the hydrophobic polyelectrolyte poly(2-ethylacrylic acid) solubilizes lipid membranes in a pH-dependent manner, and we have exploited this phenomenon to prepare lipid vesicles that release their contents in response to pH, light, or glucose (Thomas, J. L., and D. A. Tirrell. Acc. Chem. Res. 25:336-342, 1992). The physical basis for the interaction between poly(2-ethylacrylic acid) and lipid membranes has been explored using surface tensiometry and fluorimetry. Varying the polymer concentration results in changes in surface activity and membrane binding that correlate with shifts in the critical pH for membrane solubilization. Furthermore, the binding affinity is reduced as the amount of bound polymer increases. These results are consistent with a hydrophobically driven micellization process, similar to those observed with apolipoproteins, melittin, and other amphiphilic alpha-helix-based polypeptides. The absence of specific secondary structure in the synthetic polymer suggests that amphiphilicity, rather than structure, is the most important factor in membrane micellization by macromolecules. PMID:7811920

  8. Microbial enhanced oil recovery: Entering the log phase

    SciTech Connect

    Bryant, R.S.

    1995-12-31

    Microbial enhanced oil recovery (MEOR) technology has advanced internationally since 1980 from a laboratory-based evaluation of microbial processes to field applications. In order to adequately support the decline in oil production in certain areas, research on cost-effective technologies such as microbial enhanced oil recovery processes must focus on both near-term and long-term applications. Many marginal wells are desperately in need of an inexpensive improved oil recovery technology today that can assist producers in order to prevent their abandonment. Microbial enhanced waterflooding technology has also been shown to be an economically feasible technology in the United States. Complementary environmental research and development will also be required to address any potential environmental impacts of microbial processes. In 1995 at this conference, the goal is to further document and promote microbial processes for improved oil recovery and related technology for solving environmental problems.

  9. Solubilization capacity of nonionic surfactant micelles exhibiting strong influence on export of intracellular pigments in Monascus fermentation.

    PubMed

    Kang, Biyu; Zhang, Xuehong; Wu, Zhenqiang; Qi, Hanshi; Wang, Zhilong

    2013-09-01

    In this study, perstractive fermentation of intracellular Monascus pigments in nonionic surfactant micelle aqueous solution had been studied. The permeability of cell membrane modified by nonionic surfactant might have influence on the rate of export of intracellular pigments into its extracellular broth while nearly no effect on the final extracellular pigment concentration. However, the solubilization of pigments in nonionic surfactant micelles strongly affected the final extracellular pigment concentration. The solubilization capacity of micelles depended on the kind of nonionic surfactant, the super-molecule assembly structure of nonionic surfactant in an aqueous solution, and the nonionic surfactant concentration. Elimination of pigment degradation by export of intracellular Monascus pigments and solubilizing them into nonionic surfactant micelles was also confirmed experimentally. Thus, nonionic surfactant micelle aqueous solution is potential for replacement of organic solvent for perstractive fermentation of intracellular product.

  10. Solubilization capacity of nonionic surfactant micelles exhibiting strong influence on export of intracellular pigments in Monascus fermentation

    PubMed Central

    Kang, Biyu; Zhang, Xuehong; Wu, Zhenqiang; Qi, Hanshi; Wang, Zhilong

    2013-01-01

    Summary In this study, perstractive fermentation of intracellular Monascus pigments in nonionic surfactant micelle aqueous solution had been studied. The permeability of cell membrane modified by nonionic surfactant might have influence on the rate of export of intracellular pigments into its extracellular broth while nearly no effect on the final extracellular pigment concentration. However, the solubilization of pigments in nonionic surfactant micelles strongly affected the final extracellular pigment concentration. The solubilization capacity of micelles depended on the kind of nonionic surfactant, the super-molecule assembly structure of nonionic surfactant in an aqueous solution, and the nonionic surfactant concentration. Elimination of pigment degradation by export of intracellular Monascus pigments and solubilizing them into nonionic surfactant micelles was also confirmed experimentally. Thus, nonionic surfactant micelle aqueous solution is potential for replacement of organic solvent for perstractive fermentation of intracellular product. PMID:23425092

  11. Large scale solubilization of coal and bioconversion to utilizable energy. Technical progress report, January 1--March 31, 1996

    SciTech Connect

    Mishra, N.C.

    1996-05-01

    In order develop a system for a large scale coal solubilization and its bioconversion to utilizable fuel, the authors plan to clone the genes encoding Neurospora protein that facilitates depolymerization of coal. They also plan to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms. In addition the products of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein. Results are presented for the cloning of genes for Neurospora CSA-protein.

  12. Endophytic bacteria isolated from orchid and their potential to promote plant growth.

    PubMed

    Faria, Deise Cristina; Dias, Armando Cavalcante Franco; Melo, Itamar Soares; de Carvalho Costa, Francisco Eduardo

    2013-02-01

    Twelve endophytic bacteria were isolated from the meristem of in vitro Cymbidium eburneum orchid, and screened according to indole yield quantified by colorimetric assay, in vitro phosphate solubilization, and potential for plant growth promotion under greenhouse conditions. Eight strains with positive results were classified into the genus Paenibacillus by FAME profile, and evaluated for their ability to increase survival and promote the growth of in vitro germinated Cattleya loddigesii seedlings during the acclimatization process. The obtained results showed that all strains produced detectable indole levels and did not exhibit potential for solubilizing inorganic phosphate. Particularly, an increase of the total biomass and number of leaves was observed. Two strains of Paenibacillus macerans promoted plant growth under greenhouse conditions. None of the treatments had a deleterious effect on growth of inoculated plants. These results suggest that these bacterial effects could be potentially useful to promote plant growth during seedling acclimatization in orchid species other than the species of origin.

  13. Repression of oxalic acid-mediated mineral phosphate solubilization in rhizospheric isolates of Klebsiella pneumoniae by succinate.

    PubMed

    Rajput, Mahendrapal Singh; Naresh Kumar, G; Rajkumar, Shalini

    2013-02-01

    Two strains of Klebsiella (SM6 and SM11) were isolated from rhizospheric soil that solubilized mineral phosphate by secretion of oxalic acid from glucose. Activities of enzymes for periplasmic glucose oxidation (glucose dehydrogenase) and glyoxylate shunt (isocitrate lyase and glyoxylate oxidase) responsible for oxalic acid production were estimated. In presence of succinate, phosphate solubilization was completely inhibited, and the enzymes glucose dehydrogenase and glyoxylate oxidase were repressed. Significant activity of isocitrate lyase, the key enzyme for carbon flux through glyoxylate shunt and oxalic acid production during growth on glucose suggested that it could be inducible in nature, and its inhibition by succinate appeared to be similar to catabolite repression.

  14. [Kinetic characteristics of microsomal NAD-glycohydrolase natural and solubilized with a non-ionic surface-active substance].

    PubMed

    Sestini, S; Cinci, G; Ricci, C

    1982-04-30

    Microsomal rat spleen NAD-glycohydrolase was solubilized by Nonidet P40. The solubilized enzyme shows Nicotinamide inhibition and pH dependence at the same extent as unsolubilized microsomal one. It differs from the latter in having a higher affinity for NAD and NADP, and in showing two peaks, instead of one, on electrofocusing: the former with a pH 5 pI without any activity, the latter with a pH 4, 1 pI with a high NAD-ase activity.

  15. Chlorine stress mediates microbial surface attachment in drinking water systems.

    PubMed

    Liu, Li; Le, Yang; Jin, Juliang; Zhou, Yuliang; Chen, Guowei

    2015-03-01

    Microbial attachment to drinking water pipe surfaces facilitates pathogen survival and deteriorates disinfection performance, directly threatening the safety of drinking water. Notwithstanding that the formation of biofilm has been studied for decades, the underlying mechanisms for the origins of microbial surface attachment in biofilm development in drinking water pipelines remain largely elusive. We combined experimental and mathematical methods to investigate the role of environmental stress-mediated cell motility on microbial surface attachment in chlorination-stressed drinking water distribution systems. Results show that at low levels of disinfectant (0.0-1.0 mg/L), the presence of chlorine promotes initiation of microbial surface attachment, while higher amounts of disinfectant (>1.0 mg/L) inhibit microbial attachment. The proposed mathematical model further demonstrates that chlorination stress (0.0-5.0 mg/L)-mediated microbial cell motility regulates the frequency of cell-wall collision and thereby controls initial microbial surface attachment. The results reveal that transport processes and decay patterns of chlorine in drinking water pipelines regulate microbial cell motility and, thus, control initial surface cell attachment. It provides a mechanistic understanding of microbial attachment shaped by environmental disinfection stress and leads to new insights into microbial safety protocols in water distribution systems.

  16. Biogeochemistry of Microbial Mats

    NASA Technical Reports Server (NTRS)

    DesMarais, David J.; DeVincenizi, D. (Technical Monitor)

    2002-01-01

    The hierarchical organization of microbial ecosystems determines the rates of processes that shape Earth's environment, define the stage upon which major evolutionary events occurred, and create biosignatures in sediments and atmospheres. In cyanobacterial mats, oxygenic photosynthesis provides energy, organic substrates and oxygen to the ecosystem. Incident light changes with depth in the mat, both in intensity and spectral composition, and counteracting gradients of oxygen and sulfide shape the chemical microenvironment. A combination of benefits and hazards of light, oxygen and sulfide promotes the allocation of the various essential mat processes between light and dark periods and to various depths in the mat. Microliters produce hydrogen, small organic acids, nitrogen and sulfur species. Such compounds fuel a flow of energy and electrons in these ecosystems and thus shape interactions between groups of microorganisms. Coordinated observations of population distribution, abundance, and activity for an entire community are making fundamental questions in ecology accessible. These questions address those factors that sustain the remarkable diversity of microorganisms that are now being revealed by molecular techniques. These questions also target the processes that shape the various kinds of biosignatures that we will seek, both in ancient rocks from Earth and Mars, and in atmospheres of distant planets beyond our Solar System.

  17. Chaperonins as potential gene regulatory factors. In vitro interaction and solubilization of NifA, the nif transcriptional activator, with GroEL.

    PubMed

    Govezensky, D; Bochkareva, E S; Zamir, A; Girshovich, A S

    1994-05-13

    A previous study (Govezensky, D., Greener, T., and Zamir, A. (1991) J. Bacteriol. 20, 6339-6346) indicated that the chaperonin GroEL was required for maximal expression from nif promoters in Klebsiella pneumoniae and nif-transformed Escherichia coli. That this requirement stemmed from the ability of GroEL to properly fold NifA, the nif transcriptional activator, was first supported by co-immunoprecipitation of NifA in K. pneumoniae extracts with anti-GroEL antibodies. In the present in vitro study, NifA, partially purified from E. coli overexpressing the protein, was diluted from a 6 M urea solution into a refolding buffer in the presence or absence of GroEL. Dilution in the absence of GroEL caused the complete precipitation of NifA. When present in the dilution buffer, GroEL bound NifA and maintained it in a soluble state. GroEL was also found to bind NifA newly synthesized in an in vitro translation system. For both NifA preparations, cochaperonin GroES and ATP promoted release of NifA from GroEL. These results provide evidence for the association of NifA with GroEL and for the role of both GroEL and GroES in the solubilization and thereby folding of the nif transcriptional activator.

  18. Removal of mercury from coal via a microbial pretreatment process

    DOEpatents

    Borole, Abhijeet P.; Hamilton, Choo Y.

    2011-08-16

    A process for the removal of mercury from coal prior to combustion is disclosed. The process is based on use of microorganisms to oxidize iron, sulfur and other species binding mercury within the coal, followed by volatilization of mercury by the microorganisms. The microorganisms are from a class of iron and/or sulfur oxidizing bacteria. The process involves contacting coal with the bacteria in a batch or continuous manner. The mercury is first solubilized from the coal, followed by microbial reduction to elemental mercury, which is stripped off by sparging gas and captured by a mercury recovery unit, giving mercury-free coal. The mercury can be recovered in pure form from the sorbents via additional processing.

  19. Relating nanomaterial properties and microbial toxicity

    SciTech Connect

    Suresh, Anil K; Pelletier, Dale A; Doktycz, Mitchel John

    2013-01-01

    Nanomaterials are meeting diverse needs in consumer and industrial products. Metal and metal oxide nanoparticles are among the most commonly used materials and their potential for adversely affecting environmental systems raises concern. Complex microbial consortia underlie environmental processes, and the potential toxicity of nanoparticles to microbial systems, and the consequent impacts on trophic balances, is particularly worrisome. The diverse array of metal and metal oxides, the different sizes and shapes that can be prepared and the variety of possible surface coatings complicate toxicity assessments. Further complicating toxicity interpretations are the diversity of microbial systems and their metabolic capabilities. Here, we review various studies focused on nanoparticle-microbial interactions in an effort to correlate the physical-chemical properties of engineered metal and metal oxide nanoparticles to their biological response. Gaining a predictive understanding of nanoparticle toxicity, based on the physical-chemical properties of the material, will be key to the design and responsible use of nanotechnologies. General conclusions regarding the parent material of the nanoparticle and nanoparticle s size and shape on potential toxicity can be made. However, the surface coating of the material, which can be altered significantly by environmental conditions, can ameliorate or promote microbial toxicity. Understanding nanoparticle transformations and how the nanoparticle surface can be designed to control toxicity represents a key area for further study. Additionally, the vast array of microbial species and their intrinsic metabolic capabilities complicates extrapolations of nanoparticle toxicity. A molecular-based understanding of the various microbial responses to nanoparticle-induced stress is needed. Ultimately, to interpret the effect and eventual fate of engineered materials in the environment, an understanding of the relationship between nanoparticle

  20. Microbial Mineral Weathering for Nutrient Acquisition Releases Arsenic

    NASA Astrophysics Data System (ADS)

    Mailloux, B. J.; Alexandrova, E.; Keimowitz, A.; Wovkulich, K.; Freyer, G.; Stolz, J.; Kenna, T.; Pichler, T.; Polizzotto, M.; Dong, H.; Radloff, K. A.; van Geen, A.

    2008-12-01

    Tens of millions of people in Southeast Asia drink groundwater contaminated with naturally occurring arsenic. The process of arsenic release from the sediment to the groundwater remains poorly understood. Experiments were performed to determine if microbial mineral weathering for nutrient acquisition can serve as a potential mechanism for arsenic mobilization. We performed microcosm experiments with Burkholderia fungorum, phosphate free artificial groundwater, and natural apatite. Controls included incubations with no cells and with killed cells. Additionally, samples were treated with two spikes - an arsenic spike, to show that arsenic release is independent of the initial arsenic concentration, and a phosphate spike to determine whether release occurs at field relevant phosphate conditions. We show in laboratory experiments that phosphate-limited cells of Burkholderia fungorum mobilize ancillary arsenic from apatite as a by-product of mineral weathering for nutrient acquisition. The released arsenic does not undergo a redox transformation but appears to be solubilized from the apatite mineral lattice as arsenate during weathering. Apatite has been shown to be commonly present in sediment samples from Bangladesh aquifers. Analysis of apatite purified from the Ganges, Brahamputra, Meghna drainage basin shows 210 mg/kg of arsenic, which is higher than the average crustal level. Finally, we demonstrate the presence of the microbial phenotype that releases arsenic from apatite in Bangladesh sediments. These results suggest that microbial weathering for nutrient acquisition could be an important mechanism for arsenic mobilization.

  1. Anaerobic microbial transformations of radioactive wastes in subsurface environments

    SciTech Connect

    Francis, A.J.

    1984-01-01

    Radioactive wastes disposed of in subsurface environments contain a variety of radionuclides and organic compounds. Microorganisms play a major role in the transformation of organic and inorganic constituents of the waste and are partly responsible for the problems encountered at the waste disposal sites. These include microbial degradation of waste forms resulting in trench cover subsidence, migration of radionuclides, and production of radioactive gases such as /sup 14/CO/sub 2/, /sup 14/CH/sub 4/, HT, and CH/sub 3/T. Microbial processes involved in solubilization, mobilization, and immobilization of toxic metals under aerobic and anaerobic conditions are reviewed. Complexing agents and several organic acids produced by microbial action affect mobilization of radionuclides and heavy metals from the wastes. Microorganisms play a significant role in the transformation and cycling of tritium in the environment by (i) oxidation of tritium and tritiated methane under aerobic conditions and (ii) production of tritium and tritiated methane from wastes containing tritiated water and organic compounds under anaerobic conditions. 23 references, 2 figures, 2 tables.

  2. Siderophore-promoted dissolution of smectite by fluorescent Pseudomonas.

    PubMed

    Ferret, Claire; Sterckeman, Thibault; Cornu, Jean-Yves; Gangloff, Sophie; Schalk, Isabelle J; Geoffroy, Valérie A

    2014-10-01

    Siderophores are organic chelators produced by microorganisms to fulfil their iron requirements. Siderophore-promoted dissolution of iron-bearing minerals has been clearly documented for some siderophores, but few studies have addressed metabolizing siderophore-producing bacteria. We investigated iron acquisition from clays by fluorescent Pseudomonads, bacteria that are ubiquitous in the environment. We focused on the interactions between smectite and Pseudomonas aeruginosa, a bacterium producing two structurally different siderophores: pyoverdine and pyochelin. The presence of smectite in iron-limited growth media promoted planktonic growth of P. aeruginosa and biofilm surrounding the smectite aggregates. Chemical analysis of the culture media indicated increases in the dissolved silicon, iron and aluminium concentrations following smectite supplementation. The use of P. aeruginosa mutants unable to produce either one or both of the two siderophores indicated that pyoverdine, the siderophore with the higher affinity for iron, was involved in iron and aluminium solubilization by the wild-type strain. However, in the absence of pyoverdine, pyochelin was also able to solubilize iron but with a twofold lower efficiency. In conclusion, pyoverdine and pyochelin, two structurally different siderophores, can solubilize structural iron from smectite and thereby make it available for bacterial growth.

  3. Diversity and seasonal fluctuation of predominant microbial communities in Bhitarkanika, a tropical mangrove ecosystem in India.

    PubMed

    Mishra, Rashmi Ranjan; Swain, Manas Ranjan; Dangar, Tushar Kanti; Thatoi, Hrudayanath

    2012-06-01

    Different groups of microorganisms are present in mangrove areas, and they perform complex interactions for nutrient and ecological balances. Since little is known about microbial populations in mangroves, this study analyzed the microbial community structure and function in relation to soil physico-chemical properties in Bhitarkanika, a tropical mangrove ecosystem in India. Spatial and seasonal fluctuations of thirteen important groups of microorganisms were evaluated from the mangrove forest sediments during different seasons, along with soil physico-chemical parameters. The overall microbial load (x10(5)cfu/g soil) in soil declined in the order of heterotrophic, free living N2 fixing, Gram-negative nitrifying, sulphur oxidizing, Gram-positive, spore forming, denitrifying, anaerobic, phosphate solubilizing, cellulose degrading bacteria, fungi and actinomycetes. Populations of the heterotrophic, phosphate solubilizing, sulphur oxidizing bacteria and fungi were more represented in the rainy season, while, Gram-negative, Gram-positive, nitrifying, denitrifying, cellulose decomposing bacteria and actinomycetes in the winter season. The pool size of most of other microbes either declined or maintained throughout the season. Soil nutrients such as N, P, K (Kg/ha) and total C (%) contents were higher in the rainy season and they did not follow any common trend of changes throughout the study period. Soil pH and salinity (mS/cm) varied from 6-8 and 6.4-19.5, respectively, and they normally affected the microbial population dynamics. Determination of bacterial diversity in Bhitarkanika mangrove soil by culture method showed the predominance of bacterial genera such as Bacillus, Pseudomonas, Desulfotomaculum, Desulfovibrio, Desulfomonas, Methylococcus, Vibrio, Micrococcus, Klebsiella and Azotobacter. Principal component analysis (PCA) revealed a correlation among local environmental variables with the sampling locations on the microbial community in the mangrove soil.

  4. Microbial Inactivation by Ultrasound Assisted Supercritical Fluids

    NASA Astrophysics Data System (ADS)

    Benedito, Jose; Ortuño, Carmen; Castillo-Zamudio, Rosa Isela; Mulet, Antonio

    A method combining supercritical carbon dioxide (SC-CO2) and high power ultrasound (HPU) has been developed and tested for microbial/enzyme inactivation purposes, at different process conditions for both liquid and solid matrices. In culture media, using only SC-CO2, the inactivation rate of E. coli and S. cerevisiae increased with pressure and temperature; and the total inactivation (7-8 log-cycles) was attained after 25 and 140 min of SC-CO2 (350 bar, 36 °C) treatment, respectively. Using SC-CO2+HPU, the time for the total inactivation of both microorganisms was reduced to only 1-2 min, at any condition selected. The SC-CO2+HPU inactivation of both microorganisms was slower in juices (avg. 4.9 min) than in culture media (avg. 1.5 min). In solid samples (chicken, turkey ham and dry-cured pork cured ham) treated with SC-CO2 and SC-CO2+HPU, the inactivation rate of E. coli increased with temperature. The application of HPU to the SC-CO2 treatments accelerated the inactivation rate of E. coli and that effect was more pronounced in treatments with isotonic solution surrounding the solid food samples. The application of HPU enhanced the SC-CO2 inactivation mechanisms of microorganisms, generating a vigorous agitation that facilitated the CO2 solubilization and the mass transfer process. The cavitation generated by HPU could damage the cell walls accelerating the extraction of vital constituents and the microbial death. Thus, using the combined technique, reasonable industrial processing times and mild process conditions could be used which could result into a cost reduction and lead to the minimization in the food nutritional and organoleptic changes.

  5. Microbial Properties Database Editor Tutorial

    EPA Science Inventory

    A Microbial Properties Database Editor (MPDBE) has been developed to help consolidate microbial-relevant data to populate a microbial database and support a database editor by which an authorized user can modify physico-microbial properties related to microbial indicators and pat...

  6. Why Microbial Communities?

    ScienceCinema

    Fredrickson, Jim (PNNL)

    2016-07-12

    The Microbial Communities Initiative is a 5-year investment by Pacific Northwest National Laboratory that integrates biological/ecological experimentation, analytical chemistry, and simulation modeling. The objective is to create transforming technologies, elucidate mechanistic forces, and develop theoretical frameworks for the analysis and predictive understanding of microbial communities. Dr. Fredrickson introduces the symposium by defining microbial communities and describing their scientific relevance as they relate to solving problems in energy, climate, and sustainability.

  7. A Solubilized Elastin Substrate for Continuous Fluorimetric Assay of Kinetics of Elastases

    PubMed Central

    Palmier, Mark O.; Fulcher, Yan G.; Van Doren, Steven R.

    2010-01-01

    Elastolysis is central to progression of emphysema and aortic aneurysms. Characterization of steady-state enzyme kinetics of elastolysis is fettered by the insolubility of mature elastin and polydispersity of solubilized elastin. We prepared a fluor-tagged, 100 kDa fraction (fEln-100) from commercial α-elastin. It is soluble, less heterogenous in mass, cross-linked like mature elastin, and likely to retain the capacity of α-elastin to self assemble. fEln-100 has introduced the ability to compare quantitatively the apparent kcat and Km of elastases. For example, metalloelastase (MMP-12) displays higher apparent affinity for fEln-100, while MMP-2 displays faster catalytic turnover. PMID:20828532

  8. Combined effect of pH and polysorbates with cyclodextrins on solubilization of naringenin.

    PubMed

    Tommasini, S; Calabrò, M L; Raneri, D; Ficarra, P; Ficarra, R

    2004-10-29

    pH control and inclusion complex formation are commonly used as solubilization techniques in formulating ionizable drugs. Naringenin is a weakly acid compound with a low water solubility. The role of both ionized and unionized species of naringenin in solution by complexation with beta-cyclodextrin, 2-hydroxypropyl-beta-cyclodextrin and methyl-beta-cyclodextrin was investigated. This combined use of ionization and complexation increases not only the solubility of the unionized naringenin, but also that of the ionized one. This study puts on evidence the role of pH, pKa and complexation constants in increasing drug total aqueous solubility, determined by the single components in solution, as ionized and unionized naringenin both in free and complexed forms. Moreover, the presence of non-ionic surfactants in the media of complexation gives a positive contribution to the improvement of the solubility of naringenin, alone or in combination with beta-cyclodextrin.

  9. The role of ionic surfactants on the solubilization of cyclohexenone compounds in aqueous media.

    PubMed

    Nisar, Jan; Khan, Muhammad Anas; Badshah, Amir; Ilyas, Mohammad; Khan, Gul Tiaz

    2014-01-01

    The solubilization and partitioning study of five newly synthesized organic compounds (Cyclohexenone Carboxylates) with ionic surfactants, sodium dodecylsulphate (SDS) and cetyltrimethylammonium bromide (CTAB) was studied using ultraviolet-visible absorption spectroscopy technique. The differential spectroscopic technique was employed to study the partition coefficient (K(x)) of organic molecules between bulk water phase and the miceller phase. The values of partitioning coefficient were in the range 29.714 × 10(3) to 5.46 × 10(6). The standard free energy of partitioning (ΔG(op)) was also determined, which was found out in the range of -25 to -38 kJ /mole and shows the stability of the system. The results show that the cyclohexenone carboxylate compounds have great interactions with CTAB as compared to SDS.

  10. [Solubilizing effect and inclusion reaction of cyclic bisdesmosides from tubers of Bolbostemma paniculatum].

    PubMed

    Miyakoshi, M; Kasai, R; Nishioka, M; Ochiai, H; Tanaka, O

    1990-12-01

    Tubeimosides I, II and III (cyclic bisdesmosides) have been isolated from Chinese cucurbitaceous crude drug Tu-bei-mu, a tuber of Bolbostemma paniculatum (Maxim.) Franquet. Solubilizing effects of these cyclic bisdesmosides on water insoluble or less-soluble compounds were examined. It was revealed that cyclic bisdesmosides were effective on increasing the solubility of Yellow OB, dl-alpha-tocopherol and saponin A from Sapindus mukurossi. The critical micell concentration (cmc) and association number as well as diameter of micell of tubeimoside I in water were also measured. The interaction of tubeimoside I with 1-anilino-8-naphthalene-sulfonate (ANS) in aqueous solution was investigated photometrically. It was observed that tubeimoside I strongly enhanced the intensity of fluorescence of ANS, suggesting the significant formation of inclusion complex.

  11. Advanced oxidation process using hydrogen peroxide/microwave system for solubilization of phosphate.

    PubMed

    Liao, Ping Huang; Wong, Wayne T; Lo, Kwang Victor

    2005-01-01

    An advanced oxidation process (AOP) combining hydrogen peroxide and microwave heating was used for the solubilization of phosphate from secondary municipal sludge from an enhanced biological phosphorus removal process. The microwave irradiation is used as a generator agent of oxidizing radicals as well as a heating source in the process. This AOP process could facilitate the release of a large amount of the sludge-bound phosphorus from the sewage sludge. More than 84% of the total phosphorous could be released at a microwave heating time of 5 min at 170 degrees C. This innovative process has the potential of being applied to simple sludge treatment processes in domestic wastewater treatment and to the recovery of phosphorus from the wastewater.

  12. The electric dipole moment of rhodopsin solubilized in Triton X-100.

    PubMed Central

    Petersen, D C; Cone, R A

    1975-01-01

    The electric dipole moment of solubilized rhodopsin was determined with dielectric dispersion measurements. Rhodopsin was extracted from disc membranes of cattle rod outer segments with the nonionic detergent Triton X-100. The dipole moment of rhodopsin at its isoionic point in the detergent micelle is 720 D (150 charge-A). This value is comparable to dipole moments of nonmembrane proteins, especially those which tend to aggregate or polymerize. Flash irradiation of the rhodopsin results in an increase in the dipole moment of about 25 D (5 charge-A). The light-induced increase in dipole moment appears to be composed of two parts--a faster component related to a change in the number of protons bound by rhodopsin and a slower component apparently independent of the change in proton binding. PMID:1203446

  13. Membrane solubilization technique for spectrophotometric determination of trace formaldehyde in rainwater.

    PubMed

    Murai, Keita; Okano, Mayumi; Kuramitz, Hideki; Hata, Noriko; Kawakami, Takanori; Taguchi, Shigeru

    2008-01-01

    A simple and sensitive spectrophotometry for formaldehyde in water by membrane solubilization technique was proposed. Formaldehyde was converted into a blue cationic dye with 3-methyl-2-benzothiazolinone hydrazone, and the dye was retained on a membrane filter as an ion-associate with tetraphenylborate anion. The filter retaining the blue dye was dissolved in 2-methoxyethanol containing sulfuric acid, and the absorbance of the solution was measured at 670 nm against the reagent blank. The formaldehyde from 0.007 to 0.2 mg L(-1) was determined with an RSD of less than 5%, and the detection limit was 0.002 mg L(-1). The proposed method was very simple and rapid. Twenty minutes was sufficient for the entire analytical procedure. When the method was applied to rainwater, the analytical results were in good agreement with those obtained by GC/MS.

  14. Evaluation of surfactants as solubilizing agents in microsomal metabolism reactions with lipophilic substrates.

    PubMed

    Randall, Kathleen; Cheng, Shun Wen; Kotchevar, Anne Therese

    2011-10-01

    Solubilizing agents are routinely added when investigating the biotransformation of lipophilic substrates using hepatic microsomes. For highly lipophilic compounds, the concentration of solvent or surfactant necessary for dissolution can be detrimental to enzyme activity. This study evaluates the effect of 12 surfactants on microsomal metabolism and the ability of the same surfactants to improve the aqueous solubility of the pentabrominated diphenyl ether BDE-100, a lipophilic environmental contaminant previously found to be recalcitrant to in vitro metabolism. Of the surfactants investigated, Cremophor EL and Tween 80 displayed the best combination of increased BDE-100 solubility and minimal inhibition of microsomal metabolism. However, a comparison of the in vitro metabolism products of BDE-100 in the presence of the two surfactants revealed varying amounts of metabolites depending on the surfactant used.

  15. Overview of differences between microbial feed additives and probiotics for food regarding regulation, growth promotion effects and health properties and consequences for extrapolation of farm animal results to humans.

    PubMed

    Bernardeau, M; Vernoux, J-P

    2013-04-01

    For many years, microbial adjuncts have been used to supplement the diets of farm animals and humans. They have evolved since the 1990s to become known as probiotics, i.e. functional food with health benefits. After the discovery of a possible link between manipulation of gut microflora in mice and obesity, a focus on the use of these beneficial microbes that act on gut microflora in animal farming was undertaken and compared with the use of probiotics for food. Beneficial microbes added to feed are classified at a regulatory level as zootechnical additives, in the category of gut flora stabilizers for healthy animals and are regulated up to strain level in Europe. Intended effects are improvement of performance characteristics, which are strain dependent and growth enhancement is not a prerequisite. In fact, increase of body weight is not commonly reported and its frequency is around 25% of the published data examined here. However, when a Body Weight Gain (BWG) was found in the literature, it was generally moderate (lower than or close to 10%) and this over a reduced period of their short industrial life. When it was higher than 10%, it could be explained as an indirect consequence of the alleviation of the weight losses linked to stressful intensive rearing conditions or health deficiency. However, regulations on feed do not consider the health effects because animals are supposed to be healthy, so there is no requirement for reporting healthy effects in the standard European dossier. The regulations governing the addition of beneficial microorganisms to food are less stringent than for feed and no dossier is required if a species has a Qualified Presumption of Safety status. The microbial strain marketed is not submitted to any regulation and its properties (including BWG) do not need to be studied. Only claims for functional or healthy properties are regulated and again growth effect is not included. However, recent studies on probiotic effects showed that BWG

  16. Potential Application of Biohydrogen Production Liquid Waste as Phosphate Solubilizing Agent-A Study Using Soybean Plants.

    PubMed

    Sarma, Saurabh Jyoti; Brar, Satinder Kaur; LeBihan, Yann; Buelna, Gerardo

    2016-03-01

    With CO2 free emission and a gravimetric energy density higher than gasoline, diesel, biodiesel, and bioethanol, biohydrogen is a promising green renewable energy carrier. During fermentative hydrogen production, 60-70 % of the feedstock is converted to different by-products, dominated by organic acids. In the present investigation, a simple approach for value addition of hydrogen production liquid waste (HPLW) containing these compounds has been demonstrated. In soil, organic acids produced by phosphate solubilizing bacteria chelate the cations of insoluble inorganic phosphates (e.g., Ca3 (PO4)2) and make the phosphorus available to the plants. Organic acid-rich HPLW, therefore, has been evaluated as soil phosphate solubilizer. Application of HPLW as soil phosphate solubilizer was found to improve the phosphorus uptake of soybean plants by 2.18- to 2.74-folds. Additionally, 33-100 % increase in seed germination rate was also observed. Therefore, HPLW has the potential to be an alternative for phosphate solubilizing biofertilizers available in the market. Moreover, the strategy can be useful for phytoremediation of phosphorus-rich soil.

  17. Pulmonary surfactant suppressed phenanthrene adsorption on carbon nanotubes through solubilization and competition as examined by passive dosing technique.

    PubMed

    Zhao, Jian; Wang, Zhenyu; Mashayekhi, Hamid; Mayer, Philipp; Chefetz, Benny; Xing, Baoshan

    2012-05-15

    Adsorption of phenanthrene on carbon nanotubes (CNTs) was examined in the presence of pulmonary surfactant (Curosurf) and its main components, dipalmitoyl phosphatidylcholine (DPPC) and bovine serum albumin (BSA). A passive-dosing method based on equilibrium partitioning from a preloaded polymer was successfully employed to measure phenanthrene binding and speciation at controlled freely dissolved concentrations while avoiding phase separation steps. Curosurf, DPPC, and BSA could all linearly solubilize phenanthrene, and phenanthrene solubilization by Curosurf was 4 times higher than individual components (DPPC or BSA). In the presence of Curosurf, DPPC or BSA, adsorption of phenanthrene by multiwalled CNTs (MWCNTs) was suppressed, showing competitive adsorption between pulmonary surfactant (or DPPC, BSA) and phenanthrene. Competitive adsorption between Curosurf and phenanthrene was the strongest. Therefore, when phenanthrene-adsorbed CNTs enter the respiratory tract, phenanthrene can be desorbed due to both solubilization and competition. The bioaccessibility of phenanthrene adsorbed on three MWCNTs in the respiratory tract would be positively related to the size of their outer diameters. Moreover, the contribution of solubilization and competition to desorption of phenanthrene from MWCNTs was successfully separated for the first time. These findings demonstrate the two mechanisms on how pulmonary surfactants can enhance desorption and thus possibly biological absorption of phenanthrene adsorbed on CNTs.

  18. Profiling and trend analysis of food effects on oral drug absorption considering micelle interaction and solubilization by bile micelles.

    PubMed

    Kawai, Yukinori; Fujii, Yoshimine; Tabata, Fumiko; Ito, Junko; Metsugi, Yukiko; Kameda, Atsuko; Akimoto, Katsuya; Takahashi, Masayuki

    2011-01-01

    Correlation analysis between food effects on oral drug absorption (food effect) and physicochemical properties is important for efficient drug discovery and contributes to drug design. This study focused on micelle binding and solubilization considering bile micelles in the intestinal fluid. Profiling using about 40 launched drugs demonstrated that those in a high solubilization area (area 1) tended to have a positive food effect, and that drugs exhibiting negative/no food effect tended to coexist in a no/low solubilization area (area 2). In area 1, the solubilization effect by bile micelles was demonstrated quantitatively as an important factor that indicates a positive food effect. In area 2, the relative and quantitative relationships among the membrane permeation rate, dissolution rate, micelle binding and food effect could be clarified by simulation. The improvement of membrane permeability and the suppression of micelle binding are considered to be required to avoid a negative food effect. In conclusion, important factors contributing to the food effect were clarified relatively and quantitatively. Data generated from this profiling may be beneficial to find a solution for negative food effects. Furthermore, this risk assessment of food effects is considered to be a useful tool in rational drug design for drug discovery.

  19. Intestinal solubilization of particle-associated organic and inorganic mercury as a measure of bioavailability to benthic invertebrates

    SciTech Connect

    Lawrence, A.L.; McAloon, K.M.; Mason, R.P.; Mayer, L.M.

    1999-06-01

    The bioavailability of particle-associated inorganic mercury (Hg{sub I}) and monomethylmercury (MMHg) was evaluated in vitro using digestive fluid of the deposit feeding lugworm, Arenicola marina. Digestive fluid, removed from the midgut of the polychaete, was incubated with contaminated sediment, and the proportion of Hg{sub I} or MMHg solubilized by the digestive fluid was determined. Digestive fluid was found to be a more effective solvent than seawater in solubilizing particle-associated Hg{sub I} or MMHg. A greater percentage of MMHg than Hg{sub I} was solubilized from most sediments, suggesting that sediment-associated MMHg is generally more readily available from sediment for biological uptake. The proportion of MMHg released from the sediment was inversely correlated with sediment organic matter content, decreasing exponentially with increasing organic matter content of the sediment. The results for Hg{sub I} were equivocal. MMHg bioaccumulation factors (BAFs) from previous studies showed a similar trend with organic content of sediment, suggesting that solubilization may be the process limiting the bioaccumulation of particle-bound MMHg. It is concluded that in vitro extraction with a deposit feeder`s digestive fluid provides a potential tool to study the process of Hg bioaccumulation via ingestion routes, although its application to various sediments and organisms needs further investigation.

  20. Photoacoustic analysis of the solubilization kinetics of pulmonary secretions from cystic fibrosis patients - secretor and non-secretor phenotypes

    NASA Astrophysics Data System (ADS)

    Barja, P. R.; Coelho, C. C.; Paiva, R. F.; Barboza, M. A.; Matos, L. C.; Matos, C. C. B.; Oliveira, L. V. F.

    2010-03-01

    Cystic fibrosis (CF) is an autosomal recessive inherited disease that increases viscoelasticity of pulmonary secretions. Affected patients are required to use therapeutic aerosols continuously. The expression of ABH glycoconjugates in exocrine secretions determines the nature of part of the carbohydrates present in these secretions, allowing the classification of individuals into the so-called "secretor" and "non secretor" phenotypes. The aim of this work was to employ photoacoustic (PA) measurements to monitor the solubilization kinetics of pulmonary secretions from CF patients, analyzing the influence of the secretor status in the solubilization kinetics of samples nebulized with different therapeutic aerosols. Sputum samples were obtained by spontaneous expectoration from positive and negative secretor CF patients. Each sample was nebulized with i) tobramycin, ii) alpha dornase, and iii) N-acetylcysteine in a PA cell; fitting of the data with the Boltzmann equation led to the determination of t0 (typical interaction time) and Δt (solubilization interval) for each curve. Differences between the secretor and non-secretor phenotypes were statistically significant in the groups for tobramycin and alpha dornase, but not for N-acetylcysteine. Results show that the secretor status influences the solubilization of pulmonary mucus of CF patients nebulized with tobramycin and alpha dornase.

  1. Fine-tuning Nanocarriers Specifically toward Cargo: A Competitive Study on Solubilizing Related Photosensitizers for Photodynamic Therapy.

    PubMed

    Wieczorek, Sebastian; Remmler, Dario; Masini, Tiziana; Kochovski, Zdravko; Hirsch, Anna K H; Börner, Hans G

    2017-03-15

    Tailor-made drug solubilizers are studied based on peptide-poly(ethylene glycol) conjugates, which exhibit peptide segments constituting binding motifs for the small-molecule drugs of interest to render them water-soluble. Suitable 7mer peptides are selected via combinatorial means by screening large one-bead-one-compound (OBOC) peptide libraries. The capability of the screening method to read out structural detail of the drugs is investigated by comparing three related photosensitizers (Chlorin E6 (Ce6), Pheophorbide A (Pba) and meta-tetra(hydroxyphenyl)chlorin (m-THPC), which are applicable for photodynamic cancer therapy. The screening procedure delivers de novo solubilizers that show the best solubilization efficiency for the drug the screening is performed with. While molecular recognition events between peptide and drug are not expected to be found, significant binding capacity differences of, e.g., the Ce6-solubilizer for Pba are suggesting selectivity in drug binding, even among structurally closely related drugs. Cyro-Electron microscopy revealed the formation of colloidal aggregates between drug moieties and peptide conjugates. Insights into relevant amino acids in the identified peptide sequences are gained by studying capacities of systematic point mutations (alanine scans), enabling understanding of drug-binding motifs. These reveal the importance of sequence positioning of appropriate H-bonding between polar functional groups of the peptide and the drugs, which agrees well with computational binding studies performed on drug/peptide model complexes.

  2. Pirenzepine binding to membrane-bound, solubilized and purified muscarinic receptor subtypes

    SciTech Connect

    Baumgold, J.

    1986-05-01

    Muscarinic receptors were purified to near-homogeneity from bovine cortex, an area rich in the putative M1 subtype, and from bovine pons/medulla, an area rich in the putative M2 subtype. In both cases, the receptors were solubilized in digitonin and purified over an affinity column. Both the cortical and pons/medulla preparations yielded receptor proteins of 70,000 daltons. Pirenzepine binding was deduced from its competition with /sup 3/H-N-methyl scopolamine. The binding of pirenzepine to membrane-bound receptors from cortex was best described by a two site model, with approximately half the sites having a Ki of 6.4 x 10/sup -9/ M and the remaining sites having a Ki of 3.5 x 10/sup -7/ M. Membrane-bound receptors from pons/medulla bound pirenzepine according to a one-site model with a Ki of 1.1 x 10/sup -7/ M. After solubilization the two-site binding of cortical receptors became a one-site binding, Ki = 1.1 x 10/sup -7/M. This value was still five-fold lower than that of soluble receptors from pons/medulla. After purification however the affinity of pirenzepine for the pons/medulla receptor increased so that the two putative subtypes bound pirenzepine with approximately the same affinity. These findings suggest that the different pirenzepine binding characteristics used to define muscarinic receptor subtypes are not inherent in the receptor protein itself but may be due to coupling factors associated with the receptor.

  3. Solubilization and Reconstitution of Ca2+ Pump from Corn Leaf Plasma Membrane 1

    PubMed Central

    Kasai, Minobu; Muto, Shoshi

    1991-01-01

    The Ca2+ transport system of corn (Zea mays) leaf plasma membrane is composed of Ca2+ pump and Ca2+/H+ antiporter driven by H+ gradient imposed by a H+ pump (M Kasai, S Muto [1990] J Membr Biol 114: 133-142). It is necessary for characterization of these Ca2+ transporters to establish the procedure for their solubilization, isolation, and reconstitution into liposomes. We attempted to solubilize and reconstitute the Ca2+ pump in the present study. A nonionic detergent octaethyleneglycol monododecyl ether (C12E8) was the most effective detergent for a series of extraction and functional reconstitution of the Ca2+ pump among seven detergents examined. This was judged from activities of ATP-dependent 45Ca2+ uptake into liposomes reconstituted with the respective detergent-extract of the plasma membrane by the detergent dilution method. C12E8-extract of the plasma membrane was subjected to high performance liquid chromatography using a DEAE anion exchange column. Ca2+-ATPase was separated from VO43−-sensitive Mg2+-ATPase. These ATPases were separately reconstituted into liposomes, and their ATP-dependent Ca2+ uptake was measured. The liposomes reconstituted with the Ca2+-ATPase, but not with the VO43−-sensitive Mg2+-ATPase, showed ATP-dependent Ca2+ uptake. Nigericin-induced pH gradient (acid inside) caused only a little Ca2+ uptake into liposomes reconstituted with the Ca2+-ATPase, suggesting that the Ca2+/H+ antiporter was not present in the preparation. These results indicate that the Ca2+-ATPase actually functions as Ca2+ pump in the corn leaf plasma membrane. PMID:16668222

  4. Lignin-solubilizing ability of actinomycetes isolated from termite (Termitidae) gut. [Streptomyces viridosporus

    SciTech Connect

    Pasti, M.B.; Crawford, D.L. ); Pometto, A.L., III ); Nuti, M.P. )

    1990-07-01

    The lignocellulose-degrading abilities of 11 novel actinomycete strains isolated from termite gut were determined and compared with that of the well-characterized actinomycete, Streptomyces viridosporus T7A. Lignocellulose bioconversion was followed by (i) monitoring the degradation of ({sup 14}C)lignin- and ({sup 14}C)cellulose-labeled phloem of Abies concolor to {sup 14}CO{sub 2} and {sup 14}C-labeled water-soluble products, (ii) determining lignocellulose, lignin, and carbohydrate losses resulting from growth on a lignocellulose substrate prepared from corn stalks (Zea mays), and (iii) quantifying production of a water-soluble lignin degradation intermediate (acid-precipitable polymeric lignin). Of the assays used, total lignocellulose weight loss was most useful in determining overall bioconversion ability but not in identifying the best lignin-solubilizing strains. A screening procedure based on {sup 14}CO{sub 2} evolution from ({sup 14}C-lignin)lignocellulose combined with measurement of acid-precipitable polymeric lignin yield was the most effective in identifying lignin-solubilizing strains. For the termite gut strains, the pH of the medium showed no increase after 3 weeks of growth on lignocellulose. This is markedly different from the pattern observed with S. viridosporus T7A, which raises the medium pH considerably. Production of extracellular peroxidases by the 11 strains and S. viridosporus T7A was followed for 5 days in liquid cultures. On the basis of an increase of specific peroxidase activity in the presence of lignocellulose in the medium, the actinomycetes could be placed into the same three groups.

  5. Enhanced self-assembly for the solubilization of cholesterol in molecular solvent/ionic liquid mixtures.

    PubMed

    Jin, Wenbin; Ke, Yuqi; Liu, Xianxian; Yang, Qiwei; Bao, Zongbi; Su, Baogen; Ren, Qilong; Yang, Yiwen; Xing, Huabin

    2017-04-07

    The development of new solvents combining greatly enhanced solubility for sparingly soluble compounds and good kinetic properties is challenging. In this study, we constructed a family of new molecular solvent/ionic liquid (IL) mixtures with amphiphilic, anionic functional long-chain carboxylate ionic liquids (LCC-ILs) as a key component for the solubilization of sparingly soluble compounds, using cholesterol as a model solute. Polarized optical microscopy (POM), wide angle X-ray diffraction (WAXD), Fourier-transform infrared (FTIR) spectra and (1)H NMR showed that ordered mesoscopic structures, such as liquid crystals (LCs), were formed when cholesterol was dissolved in the mixtures, presenting a self-assembly induced dissolution mechanism driven by H-bond interaction and van der Waals forces in the mixtures. A synergistic effect between the molecular solvents and LCC-ILs was revealed, which contributed to enhanced solute-solvent self-assembly in dissolution over pure LCC-ILs and thus elevated solubility. Additionally, the effect of IL concentration, solvent type and anionic alkyl-chain length on self-assembly and solubility was investigated. These mixtures showed unparalleled solubilities for cholesterol, while maintaining a low viscosity. The quantitative solubilities (g g(-1)) of cholesterol were as high as 0.70, 0.84 and 0.82, respectively, at 25 °C in ethyl acetate/[P4444][C15H31COO] (50 wt%), n-heptane/[P4444][C15H31COO] (40 wt%) and ethyl acetate/[P4444][C17H35COO] (50 wt%) mixtures, which were the highest solubilities of cholesterol ever reported, six- to 980-fold higher than traditional molecular solvents and even one- to seven-fold higher compared to pure LCC-ILs. These results demonstrated the considerable potential of molecular solvent/LCC-ILs mixtures as promising solvents for solubilization and advanced separation processes.

  6. Solubilization and characterization of the VIP receptor on a human lymphoblastic cell line

    SciTech Connect

    O'Dorisio, M.S.; Compolito, L.B.; Vassalo, L.M.

    1986-03-01

    The neuropeptide, vasoactive intestinal peptide (VIP), has been shown to modulate several immune functions including lymphocyte trafficking, lymphoblastic transformation and natural killer cell activity. These actions of VIP appear to be mediated via specific, VIP preferring, receptors. Functional VIP receptors have been demonstrated on human T lymphocytes, pre B cell (CALLA+) leukemia cells and a Molt 4b lymphoblastic cell line. In this study, plasma membranes were prepared from Molt 4b lymphoblasts. The membrane fraction contained a function VIP receptor as determined by activation of adenylate cyclase which was potentiated by both guanine nucleotide and forskolin. /sup 125/I-VIP was covalently crosslinked to its receptor in membranes using the bifunctional reagent disuccinimidyl suberate. A 50,000 M/sub r/ protein comprising or associated with the VIP receptor was identified. Treatment of crosslinked membranes with endo-..beta..-N-acetylglucosaminidase F did not alter the mobility of the putative VIP receptor indicating no significant high mannose or complex glycosyl residues on the receptor molecule. Similarly, treatment of crosslinked membranes with neuroaminidase resulted in no change in mobility suggesting the absence of sialic acid residues on the putative receptor molecule. The VIP receptor was solubilized by treatment of membranes with 50 mM (3-((3-Cholamidopropyl)dimethylammonio)-1-propane sulfonate) CHAPS followed by centrifugation at 48,000 g. The crosslinked solubilized receptor again migrated at M/sur r/ = 50,000 indicating a 47K (50,000 - MW of VIP) protein. Further characterization of this receptor will allow for development of therapeutic modalities to modulate lymphocyte proliferation and function in vivo.

  7. Solubilization of a guanyl nucleotide-sensitive alpha/sub 1/ adrenergic receptor from liver membranes

    SciTech Connect

    Harris, S.I.; Moss, J.

    1987-05-01

    Rat liver membranes incubated with norepinephrine before solubilization with digitonin yielded a soluble hormone-receptor complex from which the release of tightly bound norepinephrine was facilitated by guanyl nucleotides. Binding of the alpha/sub 1/-adrenergic receptor antagonist, (/sup 3/H)-prazosin, to the soluble preparation was utilized as a gauge of guanyl nucleotide-induced release of receptor-bound agonist. The following potency series was obtained with regard to the ability of guanyl nucleotides to facilitate (/sup 3/H)-prazosin binding to the solubilized preparation: guanosine 5'-0-(3-thiotriphosphate)(K/sub 1/2/ = 2.5 nM), guanylyl-imidodiphosphate (K/sub 1/2/ = 10 nM), guanosine triphosphate (K/sub 1/2/ = 34 nM) and adenylyl-imidodiphosphate (K/sub 1/2/ > 1 mM). In the presence of guanylyl-imidodiphosphate (0.4 mM), the receptor population displayed monotonic binding parameters with a K/sub d/ for (/sup 3/H)-prazosin of 1.16 nM by Scatchard analysis. Competition curves against (/sup 3/H)-prazosin with the antagonists phentolamine and yohimbine revealed respective K/sub i/'s of .089 ..mu..M and 1.8 ..mu..M; curves with the agonists norepinephrine and isoproterenol yielded respective K/sub i/'s of 6.2..mu..M and 360 ..mu..M. Competition curves performed in the absence of guanyl nucleotide were complex demonstrating an apparent increase in affinity for agonists and an apparent decrease in affinity for antagonists. These curve shifts are consistent with the conversion of receptor to and from the guanyl nucleotide-sensitive state as a function of competing ligand concentration.

  8. Polymeric micelles for the solubilization and delivery of STAT3 inhibitor cucurbitacins in solid tumors

    PubMed Central

    Molavi, Ommoleila; Ma, Zengshuan; Mahmud, Abdullah; Alshamsan, Aws; Samuel, John; Lai, Raymond; Kwon, Glen S.; Lavasanifar, Afsaneh

    2009-01-01

    Poly(ethylene oxide)-block-poly(ε-caprolactone) (PEO-b-PCL) and newly developed poly(ethylene oxide)-block-poly(α-benzyl carboxylate ε-caprolactone) (PEO-b-PBCL) micelles were evaluated for the solubilization and delivery of cucurbitacin I and B, poorly water soluble inhibitors of signal transducer and activator of transcription 3 (STAT3). Encapsulation of cucurbitacins in PEO-b-PCL and PEO-b-PBCL by co-solvent evaporation technique resulted in polymeric micelles <90 nm in diameter. The aqueous solubility of both derivatives increased from less than 0.05 mg/mL in the absence of the copolymer to around 0.30–0.44 and 0.65–0.68 mg/mL in the presence of 5000–5000 and 5000–24,000 PEO-b-PCL micelles, respectively. Maximum cucurbitacin solubilization was achieved with PEO-b-PBCL micelles for both derivatives. PEO-b-PCL micelles having longer PCL block were found to be more efficient in sustaining the rate of release for cucurbitacins. The anti-cancer and STAT3 inhibitory activity of polymeric micellar cucurbitacins were comparable with free drugs in B16.F10 melanoma cell line in vitro. Intratumoral injection of 1 mg/kg/day cucurbitacin I resulted in the regression of established B16.F10 mouse melanoma tumors in vivo. In comparison to free cucurbitacin I, PEO-b-PBCL micellar cucurbitacin I was found to provide comparable anti-cancer effects against B16.F10 tumors and limit drug levels in animal serum while maintaining high drug levels in tumor following intratumoral administration. The results indicate the potential of polymeric micelles as suitable vehicles for the delivery of cucurbitacin- I and B. PMID:17681440

  9. Water solubilization capacity of mixed reverse micelles: effect of surfactant component, the nature of the oil, and electrolyte concentration.

    PubMed

    Paul, Bidyut K; Mitra, Rajib K

    2005-08-01

    Solubilization of water in mixed reverse micellar systems with anionic surfactant (AOT) and nonionic surfactants (Brijs, Spans, Tweens, Igepal CO 520), cationic surfactant (DDAB)-nonionic surfactants (Brijs, Spans, Igepal CO 520), and nonionic (Igepal CO 520)-nonionics (Brijs, Spans) in oils of different chemical structures and physical properties (isopropyl myristate, isobutyl benzene, cyclohexane) has been studied at 303 K. The enhancement in water solubilization has been evidenced in these systems with some exceptions. The maximum water solubilization capacity (omega(0,max)) in mixed reverse micellar systems occurred at a certain mole fraction of a nonionic surfactant, which is indicated as X(nonionic,max). The addition of electrolyte (NaCl or NaBr) in these systems tends to enhance their solubilization capacities further both at a fixed composition of nonionic (X(nonionic); 0.1) and at X(nonionic,max) at 303 K. The maximum in solubilization capacity of electrolyte (omega(max)) was obtained at an optimal electrolyte concentration (designated as [NaCl](max) or [NaBr](max)). All these parameters, omega(0,max) vis-a-vis X(nonionic,max) and omega(max) vis-a-vis [NaCl](max), have been found to be dependent on the surfactant component (content, EO chains, and configuration of the polar head group, and the hydrocarbon moiety of the nonionic surfactants) and type of oils. The conductance behavior of these systems has also been investigated, focusing on the influences of water content (omega), content of nonionics (X(nonionic)), concentration of electrolyte ([NaCl] or [NaBr]), and oil. Percolation of conductance has been observed in some of these systems and explained by considering the influences of the variables on the rigidity of the oil/water interface and attractive interactions of the surfactant aggregates. Percolation zones have been depicted in the solubilization capacity vs X(nonionic) or [electrolyte] curves in order to correlate with maximum in water or

  10. Quantification of Cholesterol Solubilized in Dietary Micelles: Dependence on Human Bile Salt Variability and the Presence of Dietary Food Ingredients.

    PubMed

    Coreta-Gomes, Filipe M; Vaz, Winchil L C; Wasielewski, Emeric; Geraldes, Carlos F G; Moreno, Maria João

    2016-05-10

    The solubility of cholesterol in bile salt (BS) micelles is important to understand the availability of cholesterol for absorption in the intestinal epithelium and to develop strategies to decrease cholesterol intake from the intestinal lumen. This has been the subject of intense investigation, due to the established relation between the development of diseases such as atherosclerosis and high levels of cholesterol in the blood. In this work we quantify the effect of BS variability on the amount of cholesterol solubilized. The effect of some known hypocholesterolemic agents usually found in the diet is also evaluated, as well as some insight regarding the mechanisms involved. The results show that, depending on the bile salt composition, the average value of sterol per micelle is equal to or lower than 1. The amount of cholesterol solubilized in the BS micelles is essentially equal to its total concentration until the solubility limit is reached. Altogether, this indicates that the maximum cholesterol solubility in the BS micellar solution is the result of saturation of the aqueous phase and depends on the partition coefficient of cholesterol between the aqueous phase and the micellar pseudophase. The effect on cholesterol maximum solubility for several food ingredients usually encountered in the diet was characterized using methodology developed recently by us. This method allows the simultaneous quantification of both cholesterol and food ingredient solubilized in the BS micelles even in the presence of larger aggregates, therefore avoiding their physical separation with possible impacts on the overall equilibrium. The phytosterols stigmasterol and stigmastanol significantly decreased cholesterol solubility with a concomitant reduction in the total amount of sterol solubilized, most pronounced for stigmasterol. Those results point toward coprecipitation being the major cause for the decrease in cholesterol solubilization by the BS micelles. The presence of

  11. The binding of cyanide to cytochrome d in intact cells, spheroplasts, membrane fragments and solubilized enzyme from Salmonella typhimurium.

    PubMed

    Keyhani, E; Minai-Tehrani, D

    2001-07-02

    This investigation focused on the kinetics of cyanide binding to oxidized and reduced cytochrome d in Salmonella typhimurium intact cells, spheroplasts, membrane fragments and solubilized enzyme, and on the effect of pH on this binding. Cyanide bound to the oxidized form of cytochrome d under all experimental conditions, inducing a trough at 649 nm in the oxidized-cyanide-minus-oxidized difference absorption spectra. V(max) of cyanide binding to oxidized cytochrome d at pH 7.0 was 14.0+/-2.0 pmol/min/mg protein (prot.) in intact cells, 37.0+/-3.5 pmol/min/mg prot. in spheroplasts, 125.0+/-6.0 pmol/min/mg prot. in membrane fragments, and 538.0+/-8.5 pmol/min/mg prot. in solubilized cytochrome d. The pseudo-first order rate constants were 0.004 s(-1) for intact cells, 0.005 s(-1) for spheroplasts, 0.007 s(-1) for membrane fragments and 0.025 s(-1) for the solubilized enzyme. The V(max) value was highest at pH 7.0 for intact cells and solubilized cytochrome d and at pH 8.0 for both spheroplasts and membrane fragments. The K(s) of binding at pH 7.0 was around 4 mM in intact cells, spheroplasts and membrane fragments, but was 10.5 mM in solubilized cytochrome d. This difference between the K(s) values suggested a change in conformation, upon solubilization, leading to a decrease in the affinity of cyanide for the solubilized enzyme. The K(s) value was nearly the same at all pH investigated (pH 5-10). Cyanide was found to also bind to the reduced form of cytochrome d in membrane fragments (K(s)=18+/-3 mM, V(max)=377+/-28 pmol/min/mg prot. at pH 7) and the solubilized enzyme (K(s)=18+/-1.2 mM, V(max)=649+/-45 pmol/min/mg prot. at pH 7) with a lower affinity of cyanide for the reduced cytochrome d than for the oxidized enzyme. Pseudo-first order rate constants were 0.025 s(-1) and 0.042 s(-1) respectively for membrane fragments and solubilized enzyme. The value of V(max) for cyanide binding to the reduced cytochrome d, whether membrane-bound or solubilized, increased

  12. Complementarity among plant growth promoting traits in rhizospheric bacterial communities promotes plant growth.

    PubMed

    Singh, Mangal; Awasthi, Ashutosh; Soni, Sumit K; Singh, Rakshapal; Verma, Rajesh K; Kalra, Alok

    2015-10-27

    An assessment of roles of rhizospheric microbial diversity in plant growth is helpful in understanding plant-microbe interactions. Using random combinations of rhizospheric bacterial species at different richness levels, we analysed the contribution of species richness, compositions, interactions and identity on soil microbial respiration and plant biomass. We showed that bacterial inoculation in plant rhizosphere enhanced microbial respiration and plant biomass with complementary relationships among bacterial species. Plant growth was found to increase linearly with inoculation of rhizospheric bacterial communities with increasing levels of species or plant growth promoting trait diversity. However, inoculation of diverse bacterial communities having single plant growth promoting trait, i.e., nitrogen fixation could not enhance plant growth over inoculation of single bacteria. Our results indicate that bacterial diversity in rhizosphere affect ecosystem functioning through complementary relationship among plant growth promoting traits and may play significant roles in delivering microbial services to plants.

  13. Investigating the Response of Microbial Communities to Cyclodextrin

    NASA Astrophysics Data System (ADS)

    Szponar, N.; Slater, G.; Smith, J.

    2009-05-01

    Recent studies have found applications of hydroxypropyl-β-cyclodextrin (HPβCD) to be highly effective in removing DDT from soils in situ. However, the persistence of HPβCD within the soil and its impact on soil microbial communities is still unclear. It has been suggested that cyclodextrin might provide a substrate for microbial communities resulting in changes in the ongoing effectiveness of remediation and/or soil hydraulic properties. The potential exists that stimulation of the soil microbial community may contribute to removal of DDT, along with the solubilization effects normally associated with cyclodextrin treatment. This study investigated the response of soil microbial communities from a site undergoing remediation of DDT with HPβCD through microcosm and bench scale column studies. Phospholipid fatty acid (PLFA) analysis and their natural abundance 13C signatures can be used to identify in situ microbial metabolism of HPβCD. Heterotrophic organisms have PLFA with 13C signatures 3 to 6‰ depleted from their carbon source. Cyclodextrin was found to have a δ13C of -16‰ resulting from its formation via enzymatic degradation of cornstarch. In contrast, soil organic matter, had a predominantly C3 plant derived signature and a δ13C of -25‰. Incorporation of HPβCD by soil microbial communities would therefore cause a shift to a more enriched isotopic value. While microcosm studies demonstrated no noticeable change in biomass and few changes in PLFA distribution, column studies treated with a 10% solution of HPβCD demonstrated an approximate doubling of microbial biomass after 6 weeks of application based on PLFA concentrations. Concurrent changes in PLFA distribution further indicated a response to cyclodextrin. Changes in PLFA concentration and distribution were concurrent with isotopic enrichment of PLFA in treated columns. This isotopic enrichment provided direct evidence for microbial consumption of cyclodextrin. Incorporation of 13C enriched

  14. Macrophage solubilization and cytotoxicity of indium-containing particles as in vitro correlates to pulmonary toxicity in vivo.

    PubMed

    Gwinn, William M; Qu, Wei; Bousquet, Ronald W; Price, Herman; Shines, Cassandra J; Taylor, Genie J; Waalkes, Michael P; Morgan, Daniel L

    2015-03-01

    Macrophage-solubilized indium-containing particles (ICPs) were previously shown in vitro to be cytotoxic. In this study, we compared macrophage solubilization and cytotoxicity of indium phosphide (InP) and indium-tin oxide (ITO) with similar particle diameters (∼ 1.5 µm) and then determined if relative differences in these in vitro parameters correlated with pulmonary toxicity in vivo. RAW 264.7 macrophages were treated with InP or ITO particles and cytotoxicity was assayed at 24 h. Ionic indium was measured in 24 h culture supernatants. Macrophage cytotoxicity and particle solubilization in vitro were much greater for InP compared with ITO. To correlate changes in vivo, B6C3F1 mice were treated with InP or ITO by oropharyngeal aspiration. On Days 14 and 28, bronchoalveolar lavage (BAL) and pleural lavage (PL) fluids were collected and assayed for total leukocytes. Cell differentials, lactate dehydrogenase activity, and protein levels were also measured in BAL. All lavage parameters were greatly increased in mice treated with InP compared with ITO. These data suggest that macrophage solubilization and cytotoxicity of some ICPs in vitro are capable of predicting pulmonary toxicity in vivo. In addition, these differences in toxicity were observed despite the two particulate compounds containing similar amounts of indium suggesting that solubilization, not total indium content, better reflects the toxic potential of some ICPs. Soluble InCl3 was shown to be more cytotoxic than InP to macrophages and lung epithelial cells in vitro further suggesting that ionic indium is the primary cytotoxic component of InP.

  15. Macrophage Solubilization and Cytotoxicity of Indium-Containing Particles as in vitro Correlates to Pulmonary Toxicity in vivo

    PubMed Central

    Gwinn, William M.; Qu, Wei; Bousquet, Ronald W.; Price, Herman; Shines, Cassandra J.; Taylor, Genie J.; Waalkes, Michael P.; Morgan, Daniel L.

    2015-01-01

    Macrophage-solubilized indium-containing particles (ICPs) were previously shown in vitro to be cytotoxic. In this study, we compared macrophage solubilization and cytotoxicity of indium phosphide (InP) and indium-tin oxide (ITO) with similar particle diameters (∼1.5 µm) and then determined if relative differences in these in vitro parameters correlated with pulmonary toxicity in vivo. RAW 264.7 macrophages were treated with InP or ITO particles and cytotoxicity was assayed at 24 h. Ionic indium was measured in 24 h culture supernatants. Macrophage cytotoxicity and particle solubilization in vitro were much greater for InP compared with ITO. To correlate changes in vivo, B6C3F1 mice were treated with InP or ITO by oropharyngeal aspiration. On Days 14 and 28, bronchoalveolar lavage (BAL) and pleural lavage (PL) fluids were collected and assayed for total leukocytes. Cell differentials, lactate dehydrogenase activity, and protein levels were also measured in BAL. All lavage parameters were greatly increased in mice treated with InP compared with ITO. These data suggest that macrophage solubilization and cytotoxicity of some ICPs in vitro are capable of predicting pulmonary toxicity in vivo. In addition, these differences in toxicity were observed despite the two particulate compounds containing similar amounts of indium suggesting that solubilization, not total indium content, better reflects the toxic potential of some ICPs. Soluble InCl3 was shown to be more cytotoxic than InP to macrophages and lung epithelial cells in vitro further suggesting that ionic indium is the primary cytotoxic component of InP. PMID:25527823

  16. Siderophores are not involved in Fe(III) solubilization during anaerobic Fe(III) respiration by Shewanella oneidensis MR-1.

    PubMed

    Fennessey, Christine M; Jones, Morris E; Taillefert, Martial; DiChristina, Thomas J

    2010-04-01

    Shewanella oneidensis MR-1 respires a wide range of anaerobic electron acceptors, including sparingly soluble Fe(III) oxides. In the present study, S. oneidensis was found to produce Fe(III)-solubilizing organic ligands during anaerobic Fe(III) oxide respiration, a respiratory strategy postulated to destabilize Fe(III) and produce more readily reducible soluble organic Fe(III). In-frame gene deletion mutagenesis, siderophore detection assays, and voltammetric techniques were combined to determine (i) if the Fe(III)-solubilizing organic ligands produced by S. oneidensis during anaerobic Fe(III) oxide respiration were synthesized via siderophore biosynthesis systems and (ii) if the Fe(III)-siderophore reductase was required for respiration of soluble organic Fe(III) as an anaerobic electron acceptor. Genes predicted to encode the siderophore (hydroxamate) biosynthesis system (SO3030 to SO3032), the Fe(III)-hydroxamate receptor (SO3033), and the Fe(III)-hydroxamate reductase (SO3034) were identified in the S. oneidensis genome, and corresponding in-frame gene deletion mutants were constructed. DeltaSO3031 was unable to synthesize siderophores or produce soluble organic Fe(III) during aerobic respiration yet retained the ability to solubilize and respire Fe(III) at wild-type rates during anaerobic Fe(III) oxide respiration. DeltaSO3034 retained the ability to synthesize siderophores during aerobic respiration and to solubilize and respire Fe(III) at wild-type rates during anaerobic Fe(III) oxide respiration. These findings indicate that the Fe(III)-solubilizing organic ligands produced by S. oneidensis during anaerobic Fe(III) oxide respiration are not synthesized via the hydroxamate biosynthesis system and that the Fe(III)-hydroxamate reductase is not essential for respiration of Fe(III)-citrate or Fe(III)-nitrilotriacetic acid (NTA) as an anaerobic electron acceptor.

  17. G-protein coupled receptor solubilization and purification for biophysical analysis and functional studies, in the total absence of detergent

    PubMed Central

    Jamshad, Mohammed; Charlton, Jack; Lin, Yu-Pin; Routledge, Sarah J.; Bawa, Zharain; Knowles, Timothy J.; Overduin, Michael; Dekker, Niek; Dafforn, Tim R.; Bill, Roslyn M.; Poyner, David R.; Wheatley, Mark

    2015-01-01

    G-protein coupled receptors (GPCRs) constitute the largest class of membrane proteins and are a major drug target. A serious obstacle to studying GPCR structure/function characteristics is the requirement to extract the receptors from their native environment in the plasma membrane, coupled with the inherent instability of GPCRs in the detergents required for their solubilization. In the present study, we report the first solubilization and purification of a functional GPCR [human adenosine A2A receptor (A2AR)], in the total absence of detergent at any stage, by exploiting spontaneous encapsulation by styrene maleic acid (SMA) co-polymer direct from the membrane into a nanoscale SMA lipid particle (SMALP). Furthermore, the A2AR–SMALP, generated from yeast (Pichia pastoris) or mammalian cells, exhibited increased thermostability (∼5°C) compared with detergent [DDM (n-dodecyl-β-D-maltopyranoside)]-solubilized A2AR controls. The A2AR–SMALP was also stable when stored for prolonged periods at 4°C and was resistant to multiple freeze-thaw cycles, in marked contrast with the detergent-solubilized receptor. These properties establish the potential for using GPCR–SMALP in receptor-based drug discovery assays. Moreover, in contrast with nanodiscs stabilized by scaffold proteins, the non-proteinaceous nature of the SMA polymer allowed unobscured biophysical characterization of the embedded receptor. Consequently, CD spectroscopy was used to relate changes in secondary structure to loss of ligand binding ([3H]ZM241385) capability. SMALP-solubilization of GPCRs, retaining the annular lipid environment, will enable a wide range of therapeutic targets to be prepared in native-like state to aid drug discovery and understanding of GPCR molecular mechanisms. PMID:25720391

  18. Native plant growth promoting bacteria Bacillus thuringiensis and mixed or individual mycorrhizal species improved drought tolerance and oxidative metabolism in Lavandula dentata plants.

    PubMed

    Armada, E; Probanza, A; Roldán, A; Azcón, R

    2016-03-15

    This study evaluates the responses of Lavandula dentata under drought conditions to the inoculation with single autochthonous arbuscular mycorrhizal (AM) fungus (five fungal strains) or with their mixture and the effects of these inocula with a native Bacillus thuringiensis (endophytic bacteria). These microorganisms were drought tolerant and in general, increased plant growth and nutrition. Particularly, the AM fungal mixture and B. thuringiensis maximized plant biomass and compensated drought stress as values of antioxidant activities [superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase APX)] shown. The AMF-bacteria interactions highly reduced the plant oxidative damage of lipids [malondialdehyde (MDA)] and increased the mycorrhizal development (mainly arbuscular formation representative of symbiotic functionality). These microbial interactions explain the highest potential of dually inoculated plants to tolerate drought stress. B. thuringiensis "in vitro" under osmotic stress does not reduce its PGPB (plant growth promoting bacteria) abilities as indole acetic acid (IAA) and ACC deaminase production and phosphate solubilization indicating its capacity to improve plant growth under stress conditions. Each one of the autochthonous fungal strains maintained their particular interaction with B. thuringiensis reflecting the diversity, intrinsic abilities and inherent compatibility of these microorganisms. In general, autochthonous AM fungal species and particularly their mixture with B. thuringiensis demonstrated their potential for protecting plants against drought and helping plants to thrive in semiarid ecosystems.

  19. Biofilms: A microbial home

    PubMed Central

    Chandki, Rita; Banthia, Priyank; Banthia, Ruchi

    2011-01-01

    Microbial biofilms are mainly implicated in etiopathogenesis of caries and periodontal disease. Owing to its properties, these pose great challenges. Continuous and regular disruption of these biofilms is imperative for prevention and management of oral diseases. This essay provides a detailed insight into properties, mechanisms of etiopathogenesis, detection and removal of these microbial biofilms. PMID:21976832

  20. Inflight microbial analysis technology

    NASA Technical Reports Server (NTRS)

    Pierson, Duane L.; Brown, Harlan D.

    1987-01-01

    This paper provides an assessment of functional characteristics needed in the microbial water analysis system being developed for Space Station. Available technology is reviewed with respect to performing microbial monitoring, isolation, or identification functions. An integrated system composed of three different technologies is presented.

  1. Metagenomics and Bioinformatics in Microbial Ecology: Current Status and Beyond

    PubMed Central

    Hiraoka, Satoshi; Yang, Ching-chia; Iwasaki, Wataru

    2016-01-01

    Metagenomic approaches are now commonly used in microbial ecology to study microbial communities in more detail, including many strains that cannot be cultivated in the laboratory. Bioinformatic analyses make it possible to mine huge metagenomic datasets and discover general patterns that govern microbial ecosystems. However, the findings of typical metagenomic and bioinformatic analyses still do not completely describe the ecology and evolution of microbes in their environments. Most analyses still depend on straightforward sequence similarity searches against reference databases. We herein review the current state of metagenomics and bioinformatics in microbial ecology and discuss future directions for the field. New techniques will allow us to go beyond routine analyses and broaden our knowledge of microbial ecosystems. We need to enrich reference databases, promote platforms that enable meta- or comprehensive analyses of diverse metagenomic datasets, devise methods that utilize long-read sequence information, and develop more powerful bioinformatic methods to analyze data from diverse perspectives. PMID:27383682

  2. Solubilization and bio-conjugation of quantum dots and bacterial toxicity assays by growth curve and plate count.

    PubMed

    Park, Soonhyang; Chibli, Hicham; Nadeau, Jay

    2012-07-11

    Quantum dots (QDs) are fluorescent semiconductor nanoparticles with size-dependent emission spectra that can be excited by a broad choice of wavelengths. QDs have attracted a lot of interest for imaging, diagnostics, and therapy due to their bright, stable fluorescence. QDs can be conjugated to a variety of bio-active molecules for binding to bacteria and mammalian cells. QDs are also being widely investigated as cytotoxic agents for targeted killing of bacteria. The emergence of multiply-resistant bacterial strains is rapidly becoming a public health crisis, particularly in the case of Gram negative pathogens. Because of the well-known antimicrobial effect of certain nanomaterials, especially Ag, there are hundreds of studies examining the toxicity of nanoparticles to bacteria. Bacterial studies have been performed with other types of semiconductor nanoparticles as well, especially TiO(2), but also ZnO and others including CuO. Some comparisons of bacterial strains have been performed in these studies, usually comparing a Gram negative strain with a Gram positive. With all of these particles, mechanisms of toxicity are attributed to oxidation: either the photogeneration of reactive oxygen species (ROS) by the particles or the direct release of metal ions that can cause oxidative toxicity. Even with these materials, results of different studies vary greatly. In some studies the Gram positive test strain is reportedly more sensitive than the Gram negative; in others it is the opposite. These studies have been well reviewed. In all nanoparticle studies, particle composition, size, surface chemistry, sample aging/breakdown, and wavelength, power, and duration of light exposure can all dramatically affect the results. In addition, synthesis byproducts and solvents must be considered. High-throughput screening techniques are needed to be able to develop effective new nanomedicine agents. CdTe QDs have anti-microbial effects alone or in combination with antibiotics. In a

  3. Inoculation with Metal-Mobilizing Plant-Growth-Promoting Rhizobacterium Bacillus sp. SC2b and Its Role in Rhizoremediation.

    PubMed

    Ma, Ying; Oliveira, Rui S; Wu, Longhua; Luo, Yongming; Rajkumar, Mani; Rocha, Inês; Freitas, Helena

    2015-01-01

    A plant growth-promoting bacterial (PGPB) strain SC2b was isolated from the rhizosphere of Sedum plumbizincicola grown in lead (Pb)/zinc (Zn) mine soils and characterized as Bacillus sp. based on (1) morphological and biochemical characteristics and (2) partial 16S ribosomal DNA sequencing analysis. Strain SC2b exhibited high levels of resistance to cadmium (Cd) (300 mg/L), Zn (730 mg/L), and Pb (1400 mg/L). This strain also showed various plant growth-promoting (PGP) features such as utilization of 1-aminocyclopropane-1-carboxylate, solubilization of phosphate, and production of indole-3-acetic acid and siderophore. The strain mobilized high concentration of heavy metals from soils and exhibited different biosorption capacity toward the tested metal ions. Strain SC2b was further assessed for PGP activity by phytagar assay with a model plant Brassica napus. Inoculation of SC2b increased the biomass and vigor index of B. napus. Considering such potential, a pot experiment was conducted to assess the effects of inoculating the metal-resistant PGPB SC2b on growth and uptake of Cd, Zn and Pb by S. plumbizincicola in metal-contaminated agricultural soils. Inoculation with SC2b elevated the shoot and root biomass and leaf chlorophyll content of S. plumbizincicola. Similarly, plants inoculated with SC2b demonstrated markedly higher Cd and Zn accumulation in the root and shoot system, indicating that SC2b enhanced Cd and Zn uptake by S. plumbizincicola through metal mobilization or plant-microbial mediated changes in chemical or biological soil properties. Data demonstrated that the PGPB Bacillus sp. SC2b might serve as a future biofertilizer and an effective metal mobilizing bioinoculant for rhizoremediation of metal polluted soils.

  4. Solubilization and characterization of haloperidol-sensitive (+)-( sup 3 H)SKF-10,047 binding sites (sigma sites) from rat liver membranes

    SciTech Connect

    McCann, D.J.; Su, T.P. )

    1991-05-01

    The zwitterionic detergent 3-((3-cholamidopropyl)dimethylamino)-1-propanesulfonate (CHAPS) produced optimal solubilization of (+)-({sup 3}H)SKF-10,047 binding sites from rat liver membranes at a concentration of 0.2%, well below the critical micellular concentration of the detergent. The pharmacological selectivity of the liver (+)-({sup 3}H)SKF-10,047 binding sites corresponds to that of sigma sites from rat and guinea pig brain. When the affinities of 18 different drugs at (+)-({sup 3}H)SKF-10,047 binding sites in membranes and solubilized preparations were compared, a correlation coefficient of 0.99 and a slope of 1.03 were obtained, indicating that the pharmacological selectivity of rat liver sigma sites is retained after solubilization. In addition, the binding of 20 nM ({sup 3}H)progesterone to solubilized rat liver preparations was found to exhibit a pharmacological selectivity appropriate for sigma sites. A stimulatory effect of phenytoin on (+)-({sup 3}H)SKF-10,047 binding to sigma sites persisted after solubilization. When the solubilized preparation was subjected to molecular sizing chromatography, a single peak exhibiting specific (+)-({sup 3}H)SKF-10,047 binding was obtained. The binding activity of this peak was stimulated symmetrically when assays were performed in the presence of 300 microM phenytoin. The molecular weight of the CHAPS-solubilized sigma site complex was estimated to be 450,000 daltons. After solubilization with CHAPS, rat liver sigma sites were enriched to 12 pmol/mg of protein. The present results demonstrate a successful solubilization of sigma sites from rat liver membranes and provide direct evidence that the gonadal steroid progesterone binds to sigma sites. The results also suggest that the anticonvulsant phenytoin binds to an associated allosteric site on the sigma site complex.

  5. Signaling in host-associated microbial communities

    PubMed Central

    Fischbach, Michael A.; Segre, Julia A.

    2016-01-01

    Human-associated microbiota form and stabilize communities based on interspecies interactions. We review how these microbe-microbe and microbe-host interactions are communicated to shape communities over a human’s lifespan, including periods of health and disease. Modeling and dissecting signaling in host-associated communities is crucial to understand their function, and will open the door to therapies that prevent or correct microbial community dysfunction to promote health and treat disease. PMID:26967294

  6. Anaerobic microbial remobilization of coprecipitated metals

    DOEpatents

    Francis, A.J.; Dodge, C.J.

    1994-10-11

    A process is provided for solubilizing coprecipitated metals. Metals in waste streams are concentrated by treatment with an iron oxide coprecipitating agent. The coprecipitated metals are solubilized by contacting the coprecipitate with a bacterial culture of a Clostridium species ATCC 53464. The remobilized metals can then be recovered and recycled. 4 figs.

  7. Anaerobic microbial remobilization of coprecipitated metals

    DOEpatents

    Francis, Arokiasamy J.; Dodge, Cleveland J.

    1994-10-11

    A process is provided for solubilizing coprecipitated metals. Metals in wastestreams are concentrated by treatment with an iron oxide coprecipitating agent. The coprecipitated metals are solubilized by contacting the coprecipitate with a bacterial culture of a Clostridium species ATCC 53464. The remobilized metals can then be recovered and recycled.

  8. Assessment of Culturable Tea Rhizobacteria Isolated from Tea Estates of Assam, India for Growth Promotion in Commercial Tea Cultivars

    PubMed Central

    Dutta, Jintu; Handique, Pratap J.; Thakur, Debajit

    2015-01-01

    In the present study, 217 rhizobacterial isolates were obtained from six different tea estates of Assam, India and subjected to preliminary in vitro plant growth promotion (PGP) screening for indole acetic acid (IAA) production, phosphate solubilization, siderophore production and ammonia production. Fifty isolates showed all the PGP traits and five isolates did not exhibit any PGP traits. These 50 potential isolates were further analyzed for quantitative estimation of the PGP traits along with the aminocyclopropane-1-carboxylate (ACC) deaminase, protease and cellulose production. After several rounds of screening, four rhizobacteria were selected based on their maximum ability to produce in vitro PGP traits and their partial 16S rRNA gene sequence analysis revealed that they belong to Enterobacter lignolyticus strain TG1, Burkholderia sp. stain TT6, Bacillus pseudomycoides strain SN29 and Pseudomonas aeruginosa strain KH45. To evaluate the efficacy of these four rhizobacteria as plant growth promoters, three different commercially important tea clones TV1, TV19, and TV20 plants were inoculated with these rhizobacteria in greenhouse condition and compared to the uninoculated control plants. Though, all the rhizobacterial treatments showed an increase in plant growth compared to control but the multivariate PCA analysis confirmed more growth promotion by TG1 and SN29 strains than the other treatments in all three clones. To validate this result, the fold change analysis was performed and it revealed that the tea clone TV19 plants inoculated with the E. lignolyticus strain TG1 showed maximum root biomass production with an increase in 4.3-fold, shoot biomass with increase in 3.1-fold, root length by 2.2-fold and shoot length by 1.6-fold. Moreover, two way ANOVA analysis also revealed that rhizobacterial treatment in different tea clones showed the significant increase (P < 0.05) in growth promotion compared to the control. Thus, this study indicates that the

  9. Quantitation of microbial products and their effectiveness in enhanced oil recovery. Final report

    SciTech Connect

    Zhang, X.; Knapp, R.M.; McInerney, M.J.

    1995-02-01

    A three-dimensional, three-phase, multiple-component numerical simulator was developed to investigate transport and growth of microorganisms in porous media and the impacts of microbial activities on oil recovery. The microbial activities modeled in this study included: (1) growth, retention, chemotaxis, and end product inhibition of growth, (2) the formation of metabolic products, and (3) the consumption of nutrients. Major mechanisms for microbial enhanced oil recovery (MEOR) processes were modeled as follows: (1) improvement in sweep efficiency of a displacement process due to in situ plugging of highly-permeable production zones by cell mass or due to improved mobility control achieved by increasing the viscosity of the displacing fluid with a biopolymer, and (2) solubilization and mobilization of residual oil in porous media due to the reduction of the interfacial tension between oleic and aqueous phases by the production of a biosurfactant. The numerical solutions for mathematical models involved two steps. The distributions of pressure and phase saturations were solved from continuity equations and Darcy flow velocities for the aqueous phase were computed. This was followed by the solution of convection-dispersion equations for individual components. Numerical solutions from the proposed model were compared to results obtained from analytical equations, commercial simulators, and laboratory experiments. The comparison indicated that the model accurately quantified microbial transport and metabolism in porous media, and predicted additional crude oil recovery due to microbial processes. 50 refs., 41 figs., 26 tabs.

  10. Bioinformatics based structural characterization of glucose dehydrogenase (gdh) gene and growth promoting activity of Leclercia sp. QAU-66.

    PubMed

    Naveed, Muhammad; Ahmed, Iftikhar; Khalid, Nauman; Mumtaz, Abdul Samad

    2014-01-01

    Glucose dehydrogenase (GDH; EC 1.1. 5.2) is the member of quinoproteins group that use the redox cofactor pyrroloquinoline quinoine, calcium ions and glucose as substrate for its activity. In present study, Leclercia sp. QAU-66, isolated from rhizosphere of Vigna mungo, was characterized for phosphate solubilization and the role of GDH in plant growth promotion of Phaseolus vulgaris. The strain QAU-66 had ability to solubilize phosphorus and significantly (p ≤ 0.05) promoted the shoot and root lengths of Phaseolus vulgaris. The structural determination of GDH protein was carried out using bioinformatics tools like Pfam, InterProScan, I-TASSER and COFACTOR. These tools predicted the structural based functional homology of pyrroloquinoline quinone domains in GDH. GDH of Leclercia sp. QAU-66 is one of the main factor that involved in plant growth promotion and provides a solid background for further research in plant growth promoting activities.

  11. Large scale solubilization of coal and bioconversion to utilizable energy. Eighth quarterly technical progress report, July 1, 1995--September 30, 1995

    SciTech Connect

    Mishra, N.C.

    1996-02-01

    In order to develop a system for a large scale coal solubilization and its bioconversion to utilizable fuel, we plan to clone the genes encoding Neurospora protein that facilitate depolymerization of coal. We also plan to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms. In addition the product of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein.

  12. Large scale solubilization of coal and bioconversion to utilizable energy. Seventh quarterly technical progress report, April 1, 1995--June 30, 1995

    SciTech Connect

    Mishra, N.C.

    1995-12-01

    In order to develop a system for a large scale coal solubilization and its bioconversion to utilizable fuel, we plan to clone the genes encoding Neurospora protein that facilitate depolymerization of coal. We also plan to use desulfurizing bacteria to remove the sulfur in situ and use other microorganisms to convert biosolubilized coal into utilizable energy following an approach utilizing several microorganisms. In addition the product of coal solubilized by fungus will be characterized to determine their chemical nature and the mechanism of reaction catalyzed by fungal product during in vivo and in vitro solubilization by the fungus or purified fungal protein.

  13. A biophysical index for predicting hydration-mediated microbial diversity in soils

    NASA Astrophysics Data System (ADS)

    Wang, G.; Or, D.

    2012-04-01

    Exploring the origins of soil microbial diversity represents an immense and uncharted scientific frontier. Progress in resolving mechanisms that promote and sustain the unparalleled soil microbial diversity found in soil requires development of process-based predictive tools that consider dynamic biophysical interactions at highly resolved spatial and temporal scales. We report a novel biophysical metric for hydration-mediated microbial coexistence in soils by integrating key biophysical variables, such as aquatic habitat size and connectivity, nutrient diffusion affecting microbial growth, and aqueous films controlling motility and dispersal, into a predictive index. Results show a surprisingly narrow range of hydration conditions (a few kPa) that mark a sharp transition from suppression (wet) to promotion (dry) of microbial diversity in unsaturated soils in agreement with limited observations and with simulation results based on individual-based models of competing populations. The framework enables systematic hypothesis testing for key factors that regulate microbial populations and affect soil bio-geochemical functions, and represents a step towards deciphering key mechanisms that support soil microbial diversity. New insights into the different roles of biophysical mechanisms in promoting soil microbial diversity enable predictions concerning microbial consortia function and bioremediation activities in soils, and may shape how we quantify microbial diversity within the context of land resources and biogeochemical cycling.

  14. [The effect of thermal power plant on microbial ecology and environmental quality].

    PubMed

    Yang, S S; Yang, C K; Chang, E H; Wei, C B

    1999-12-01

    To investigate the effect of thermal power plant on the microbial ecology and the environmental quality, the Hsieh-Ho Thermal Power Plant was chosen and the populations of microbes including bacteria, actinomycetes, fungi, and cellulolytic, phosphate-solubilizing and nitrogen-fixing microbes were selected as the parameters of microbial ecology. The pH values of the soil sample collected from inside and outside of the plant were 5.2-6.2 and 4.0-5.3, respectively. Moisture content in plant area was lower than that in the surrounding area. Microbial populations of the topsoils were higher than those of the subsoils. Each gram of soil contained 3.64 x 10(4)-5.16 x 10(7) colonies of bacteria, 1.75 x 10(3)-1.10 x 10(6) colonies of actinomycetes and 6.72 x 10(3)-8.78 x 10(6) colonies of fungi in the plant area; while they were 5.52 x 10(4)-2.14 x 10(7), 8.26 x 10(3)-7.25 x 10(5) and 3.49 x 10(3)-2.74 x 10(6) colonies of bacteria, actinomycetes and fungi, respectively, in the surrounding area. The effect of seasonal change on microbial populations was not significant. The ratio of cellulolytic, phosphate-solubilizing and nitrogen-fixing microbes to the total count in the plant area was also higher than that in the surrounding area, and some of them had significant differences. From the statistical analysis, the effect of thermal power generator on the population and distribution of microbes was significantly different.

  15. Definition and characterization of enzymes for maximal biocatalytic solubilization of prebiotic polysaccharides from potato pulp.

    PubMed

    Thomassen, Lise V; Larsen, Dorte M; Mikkelsen, Jørn D; Meyer, Anne S

    2011-08-10

    Potato pulp is a high-volume co-processing product resulting from industrial potato starch manufacturing. Potato pulp is particularly rich in pectin, notably galactan branched rhamnogalacturonan I polysaccharides, which are highly bifidogenic when solubilized. The objective of the present study was to characterize and compare four homogalacturonan degrading enzymes capable of catalyzing the required solubilization of these pectinaceous polysaccharides from potato pulp in a 1 min reaction. An additional purpose was to assess the influence of the pH and the potential buffer chelating effects on the release of these polysaccharides from the potato pulp. The pH and temperature optima of two selected pectin lyases from Emericella nidulans (formerly known as Aspergillus nidulans) and Aspergillus niger were determined to 8.6 and 4.0, respectively, at ≥100 °C within 1 min of reaction. The optima for the two selected polygalacturonases from E. nidulans and Aspergillus aculeatus were determined to pH 4.4 and 46 °C, and pH 3.7 and ≥80 °C, respectively. The polygalacturonase from A. aculeatus was 4-42 times more heat-resistant at 50 °C than the other enzymes. The difference in pH optima of the pectin lyases and the exceptional thermal stabilities of some of the enzymes are proposed to be related to specific amino acid substitutions, stabilizing hydrogen bonding and structural traits of the enzymes. The K(M) and V(max) values ranged from 0.3-0.6g/L and 0.5-250.5 U/mg protein, respectively. Phosphate buffer induced release of a higher amount of dry matter than Tris-acetate buffer at pH 6, indicating a chelating effect of the phosphate. Moreover, the phosphate had a higher chelating effect at pH 6 than at pH 4. The optimal conditions for a high yield of polysaccharides from potato pulp were therefore: 1% (w/w) potato pulp treated with 1% (w/w) enzyme/substrate (E/S) pectin lyase from E. nidulans and 1% (w/w) E/S polygalacturonase from A. aculeatus at pH 6.0 and 60 °C for

  16. Alkaline solubilization and microwave irradiation as a combined sludge disintegration and minimization method.

    PubMed

    Doğan, Ilgin; Sanin, F Dilek

    2009-05-01

    Commonly used pretreatment method of alkaline solubilization (using NaOH) and a relatively new technology of microwave (MW) irradiation (160 degrees C) were combined as a pretreatment method of waste activated sludge (WAS) in this study. First alkaline and MW pretreatment methods were examined separately, then their combination for different conditions was investigated in terms of their effect on COD solubilization, turbidity and capillary suction time (CST). For combined pretreatments, soluble COD to total COD ratio (SCOD/TCOD) of WAS increased from 0.005 (control) to 0.18, 0.27, 0.34 and 0.37 for combined methods of MW and pH-10, 11, 12 and 12.5, respectively. Deteriorated dewaterability due to alkaline pretreatment was also improved due to the incorporation of MW irradiation. Further, with small scale batch anaerobic reactors, pH-10, pH-12, MW (alone), MW+pH-10 and MW+pH-12 pretreated WAS samples were anaerobically digested. Highest total gas and methane productions were achieved with MW+pH-12 pretreatment with 16.3% and 18.9% improvements over control reactor, respectively. Finally the performance of MW+pH-12 pretreatment was examined with 2L anaerobic semi-continuous reactors for 92 days and compared to that of the control reactors. These reactors were operated at an SRT of 15 days. After steady state, 43.5% and 55% improvements were obtained in respective daily total gas and methane productions. TS, VS and TCOD reductions were improved by 24.9%, 35.4% and 30.3%, respectively based on a relative calculation with respect to control reactors. This way combined alkaline-microwave treatment proved to be an effective sludge minimization method. Pretreated digested sludge had 22% improved dewaterability than unpretreated digested sludge. Higher SCOD and NH(3)-N concentrations were measured in the pretreated digested sludge supernatant; however, PO(4)-P concentration did not increase much.

  17. High-level production, solubilization and purification of synthetic human GPCR chemokine receptors CCR5, CCR3, CXCR4 and CX3CR1.

    PubMed

    Ren, Hui; Yu, Daoyong; Ge, Baosheng; Cook, Brian; Xu, Zhinan; Zhang, Shuguang

    2009-01-01

    Chemokine receptors belong to a class of integral membrane G-protein coupled receptors (GPCRs) and are responsible for transmitting signals from the extracellular environment. However, the structural changes in the receptor, connecting ligand binding to G-protein activation, remain elusive for most GPCRs due to the difficulty to produce them for structural and functional studies. We here report high-level production in E.coli of 4 human GPCRs, namely chemokine receptors (hCRs) CCR5, CCR3, CXCR4 and CX3CR1 that are directly involved in HIV-1 infection, asthma and cancer metastasis. The synthetic genes of CCR5, CCR3, CXCR4 and CX3CR1 were synthesized using a two-step assembly/amplification PCR method and inserted into two different kinds of expression systems. After systematic screening of growth conditions and host strains, TB medium was selected for expression of pEXP-hCRs. The low copy number pBAD-DEST49 plasmid, with a moderately strong promoter tightly regulated by L-arabinose, proved helpful for reducing toxicity of expressed membrane proteins. The synthetic Trx-hCR fusion genes in the pBAD-DEST49 vector were expressed at high levels in the Top10 strain. After a systematic screen of 96 detergents, the zwitterionic detergents of the Fos-choline series (FC9-FC16) emerged as the most effective for isolation of the hCRs. The FC14 was selected both for solubilization from bacterial lysates and for stabilization of the Trx-hCRs during purification. Thus, the FC-14 solubilized Trx-hCRs could be purified using size exclusion chromatography as monomers and dimers with the correct apparent MW and their alpha-helical content determined by circular dichroism. The identity of two of the expressed hCRs (CCR3 and CCR5) was confirmed using immunoblots using specific monoclonal antibodies. After optimization of expression systems and detergent-mediated purification procedures, we achieved large-scale, high-level production of 4 human GPCR chemokine receptor in a two

  18. Expansion of Microbial Forensics

    PubMed Central

    Schmedes, Sarah E.; Sajantila, Antti

    2016-01-01

    Microbial forensics has been defined as the discipline of applying scientific methods to the analysis of evidence related to bioterrorism, biocrimes, hoaxes, or the accidental release of a biological agent or toxin for attribution purposes. Over the past 15 years, technology, particularly massively parallel sequencing, and bioinformatics advances now allow the characterization of microorganisms for a variety of human forensic applications, such as human identification, body fluid characterization, postmortem interval estimation, and biocrimes involving tracking of infectious agents. Thus, microbial forensics should be more broadly described as the discipline of applying scientific methods to the analysis of microbial evidence in criminal and civil cases for investigative purposes. PMID:26912746

  19. Amplification of plant beneficial microbial communities during conversion of coconut leaf substrate to vermicompost by Eudrilus sp.

    PubMed

    Gopal, Murali; Gupta, Alka; Sunil, E; Thomas, George V

    2009-07-01

    The population densities of 15 microbial communities in the coconut leaves + cow manure mixture (10:1 ratio, w/w) and pure cow manure, gut contents of the earthworm, Eudrilus sp., reared on the above substrates and vermicompost produced by the worm were studied. The enumeration was done by dilution plate and most probable number method using several selective and semi-selective microbial media. In the vermicompost produced from coconut leaves + cow manure (CLV) mixture, 9 out of 15 microbial communities, particularly the plant beneficial ones, were amplified whereas five communities were amplified in case of pure cow manure (CMV). The CLV contained significantly high population of fungi, free-living nitrogen fixers, phosphate solubilizers, fluorescent pseudomonads, and silicate solubilizers. The CMV was preponderant with aerobic heterotrophic bacteria, actinomycetes, and Trichoderma spp. Spore formers were present in similar numbers in both the vermicomposts. Presence of Azotobacter was detected only in CMV. The results obtained in this study suggest coconut leaf litter to be a good alternative for cow manure for the production of vermicompost, especially in the areas where coconut is grown in plenty.

  20. DNA-Assisted Solubilization of Carbon Nanotubes and Construction of DNA-MWCNT Cross-Linked Hybrid Hydrogels

    PubMed Central

    Zinchenko, Anatoly; Taki, Yosuke; Sergeyev, Vladimir G.; Murata, Shizuaki

    2015-01-01

    A simple method for preparation of DNA-carbon nanotubes hybrid hydrogel based on a two-step procedure including: (i) solubilization of multi-walled carbon nanotubes (MWCNT) in aqueous solution of DNA, and (ii) chemical cross-linking between solubilized MWCNT via adsorbed DNA and free DNA by ethylene glycol diglycidyl ether is reported. We show that there exists a critical concentration of MWCNT below which a homogeneous dispersion of MWCNT in hybrid hydrogel can be achieved, while at higher concentrations of MWCNT the aggregation of MWCNT inside hydrogel occurs. The strengthening effect of carbon nanotube in the process of hydrogel shrinking in solutions with high salt concentration was demonstrated and significant passivation of MWCNT adsorption properties towards low-molecular-weight aromatic binders due to DNA adsorption on MWCNT surface was revealed.

  1. Detergent-solubilized Patched purified from Sf9 cells fails to interact strongly with cognate Hedgehog or Ihog homologs.

    PubMed

    Cleveland, Thomas E; McCabe, Jacqueline M; Leahy, Daniel J

    2014-12-01

    Patched (Ptc) is a twelve-pass transmembrane protein that functions as a receptor for the Hedgehog (Hh) family of morphogens. In addition to Ptc, several accessory proteins including the CDO/Ihog family of co-receptors are necessary for proper Hh signaling. Structures of Hh proteins bound to members of the CDO/Ihog family are known, but the nature of the full Hh receptor complex is not well understood. We have expressed the Drosophila Patched and Mouse Patched-1 proteins in Sf9 cells and find that Sonic Hedgehog will bind to Mouse Patched-1 in isolated Sf9 cell membranes but that purified, detergent-solubilized Ptc proteins do not interact strongly with cognate Hh and CDO/Ihog homologs. These results may reflect a nonnative conformation of detergent-solubilized Ptc or that an additional factor or factors lost during purification are required for high-affinity Ptc binding to Hh.

  2. Stable and solubilized active Au atom clusters for selective epoxidation of cis-cyclooctene with molecular oxygen

    PubMed Central

    Qian, Linping; Wang, Zhen; Beletskiy, Evgeny V.; Liu, Jingyue; dos Santos, Haroldo J.; Li, Tiehu; Rangel, Maria do C.; Kung, Mayfair C.; Kung, Harold H.

    2017-01-01

    The ability of Au catalysts to effect the challenging task of utilizing molecular oxygen for the selective epoxidation of cyclooctene is fascinating. Although supported nanometre-size Au particles are poorly active, here we show that solubilized atomic Au clusters, present in ng ml−1 concentrations and stabilized by ligands derived from the oxidized hydrocarbon products, are active. They can be formed from various Au sources. They generate initiators and propagators to trigger the onset of the auto-oxidation reaction with an apparent turnover frequency of 440 s−1, and continue to generate additional initiators throughout the auto-oxidation cycle without direct participation in the cycle. Spectroscopic characterization suggests that 7–8 atom clusters are effective catalytically. Extension of work based on these understandings leads to the demonstration that these Au clusters are also effective in selective oxidation of cyclohexene, and that solubilized Pt clusters are also capable of generating initiators for cyclooctene epoxidation. PMID:28348389

  3. Phagocyte NADPH-oxidase. Studies with flavin analogues as active site probes in triton X-100-solubilized preparations.

    PubMed

    Parkinson, J F; Gabig, T G

    1988-06-25

    NADPH-oxidase of stimulated human neutrophil membranes was solubilized in Triton X-100 and activity reconstituted with FAD, 8-F-FAD, 8-phenyl-S-FAD, and 8-S-FAD. The enzyme had similar affinities for all the flavins with Km values in the 60-80 nM range. Vmax was found to increase 4-fold with increasing redox midpoint potential of the flavin. 8-F-FAD reconstituted with the enzyme was reactive toward thiophenol, suggesting exposure of the 8-position to solvent, a finding supported by unsuccessful attempts to label the enzyme with the photoaffinity probe 8-N3-[32P]FAD. Solubilized oxidase stabilized the red thiolate form of 8-S-FAD, a characteristic of flavoproteins of the dehydrogenase/electron transferase classes which stabilize the blue neutral form of the flavin semiquinone radical.

  4. Solubilization of matrix protein M1/M from virions occurs at different pH for orthomyxo- and paramyxoviruses.

    PubMed

    Zhirnov, O P

    1990-05-01

    Enveloped viruses, of which the orthomyxo- and paramyxoviruses are members, are known to be uncoated by nonionic detergents in a salt concentration-dependent manner. In this study we have shown that detergent uncoating of myxoviruses depends not only on salt concentration but also on pH. Treatment of orthomyxoviruses with Nonidet-P40 or Triton N-101 at low salt concentrations results in solubilization of surface virion glycopolypeptides in alkaline and neutral pH (9.0-6.5), but in acidic pH (6.0-5.0) the viral matrix protein M1 is also removed, and the viral ribonucleoprotein complex is released. Conversely, the paramyxovirus matrix protein M is more completely solubilized in alkaline pH (pH 9.0) than in neutral and acidic pH 7.4-5.0. The described pH-dependent differences are discussed in terms of orthomyxo- and paramyxovirus uncoating in target cells.

  5. Yeast manno-protein biosynthesis: solubilization and selective assay of four mannosyltransferases.

    PubMed Central

    Nakajima, T; Ballou, C E

    1975-01-01

    Using appropriate yeast strains and exogenous acceptors, we have devised specific assays for four mannosyltransferase activities involved in biosynthesis of the carbohydrate outer chain of yeast mannoproteins. The assays utilize GDP-[14C]mannose as the donor and unlabeled oligosaccharides as the acceptors, the products being neutral radioactive oligosaccharides one mannose unit larger than the acceptors. The multiglycosyltransferase system from Saccharomyces cerevisiae was solubilized in Triton X-100 and urea and purified 100-fold. Free mannose is an acceptor for the alpha1 leads to 2-mannosyltransferase, the major product being alpha[14C]Man leads to 2Man. The alpha1 leads to 6-mannooligosaccharides serve as acceptors for both the alpha1 leads to 2- and alpha1 leads to 6-transferases, but the tetrasaccharide alphaMan leads to 3alphsMan leads to 2alphaMan is a specific acceptor for the latter enzyme and yields (see article). When reduced, this same tetrasaccharide serves as the acceptor for an alpha1 leads to 3-mannosyltransferase from Saccharomyces chevalieri, yielding a pentasaccharide with two terminal 1 leads to 3 linkages. Assay of the alpha1 leads to 3-transferase in S. cerevisiae utilizes reduced alpha1 leads to 2-mannotriose as the acceptor, the product being alpha[14C]Man leads to 3alphaMan leads to 2alphaMan leads to 2Mannitol. The multienzyme system works in concert to make "mannan" in a cell-free in vitro system. Images PMID:1105568

  6. Structural properties of pepsin-solubilized collagen acylated by lauroyl chloride along with succinic anhydride.

    PubMed

    Li, Conghu; Tian, Zhenhua; Liu, Wentao; Li, Guoying

    2015-10-01

    The structural properties of pepsin-solubilized calf skin collagen acylated by lauroyl chloride along with succinic anhydride were investigated in this paper. Compared with native collagen, acylated collagen retained the unique triple helix conformation, as determined by amino acid analysis, circular dichroism and X-ray diffraction. Meanwhile, the thermostability of acylated collagen using thermogravimetric measurements was enhanced as the residual weight increased by 5%. With the temperature increased from 25 to 115 °C, the secondary structure of native and acylated collagens using Fourier transform infrared spectroscopy measurements was destroyed since the intensity of the major amide bands decreased and the positions of the major amide bands shifted to lower wavenumber, respectively. Meanwhile, two-dimensional correlation spectroscopy revealed that the most sensitive bands for acylated and native collagens were amide I and II bands, respectively. Additionally, the corresponding order of the groups between native and acylated collagens was different and the correlation degree for acylated collagen was weaker than that of native collagen, suggesting that temperature played a small influence on the conformation of acylated collagen, which might be concluded that the hydrophobic interaction improved the thermostability of collagen.

  7. Conjugated Polyelectrolytes with Imidazolium Solubilizing Groups. Properties and Application to Photodynamic Inactivation of Bacteria.

    PubMed

    Parthasarathy, Anand; Pappas, Harry C; Hill, Eric H; Huang, Yun; Whitten, David G; Schanze, Kirk S

    2015-12-30

    This article reports an investigation of the photophysical properties and the light- and dark-biocidal activity of two poly(phenyleneethynylene) (PPE)-based conjugated polyelectrolytes (CPEs) bearing cationic imidazolium solubilizing groups. The two polymers feature the same PPE-type backbone, but they differ in the frequency of imidazoliums on the chains: PIM-4 features two imidazolium units on every phenylene repeat, whereas PIM-2 contains two imidazolium units on every other phenylene unit. Both polymers are very soluble in water and polar organic solvents, but their propensity to aggregate in water differs with the density of the imidazolium units. The polymers are highly fluorescent, and they exhibit the amplified quenching effect when exposed to a low concentration of anionic electron-acceptor anthraquinone disulfonate. The CPEs are also quenched by a relatively low concentration of pyrophosphate by an aggregation-induced quenching mechanism. The biocidal activity of the cationic imidazolium CPEs was studied against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus bacteria in the dark and under blue-light illumination. Both polymers are effective biocides, exhibiting greater than 3 log kill with 30-60 min of light exposure at concentrations of ≤10 μg mL(-1).

  8. Graphene-zinc oxide nanorods nanocomposite based sensor for voltammetric quantification of tizanidine in solubilized system

    NASA Astrophysics Data System (ADS)

    Jain, Rajeev; Dhanjai; Sinha, Ankita

    2016-04-01

    A new graphene/zinc oxide nanorods modified glassy carbon electrode (GR/ZnORs/GCE) based electrochemical sensor has been developed for the sensitive determination tizanidine (TZ) in solubilized system. The fabricated sensor was characterized by various electrochemical methods. Different kinetic parameters affecting the monitored electrocatalytic response were investigated and optimized for tizanidine determination at fabricated GR/ZnORs/GCE sensor and successfully compared with the results obtained at GR/SiO2/GCE, GR/GCE and at bare GCE. Under optimized conditions the square wave current is linear over the concentration range 0.80 ng mL-1 to 10.0 μg mL-1 with detection limit and quantification limit of 0.10 ng mL-1 and 3.45 ng mL-1 respectively. The applicability of proposed method is further extended to in vitro determination of the drug in pharmaceutical formulation with an acceptable recovery from 97.89% to 101.09%.

  9. Use of osmolytes during solubilization and reconstitution of phosphate: sugar phosphate antiport from bacteria

    SciTech Connect

    Ambudkar, S.V.; Sonna, L.A.; Maloney, P.C.

    1986-05-01

    Phosphate:2-deoxyglucose 6-phosphate (Pi:2DG6P) antiport was extracted from Streptococcus lactis or Staphylococcus aureus with 1.1% octylglucoside in the presence of 0.37% E. coli lipid and reconstituted by detergent dilution. Because previous work suggested inactivation at an early stage, the authors introduced protein stabilants during solubilization. When 20% glycerol was used, proteoliposomes showed a 20-fold increase in /sup 32/Pi transport. This enhanced recovery required phospholipid plus glycerol, and was found only when both were added together with the detergent. Glycerol protection yielded proteoliposomes in which antiporters retained their normal kinetic properties, and Pi exchange by the streptococcal example gave a maximal rate (200-400 nmol/min per mg protein) and a turnover number (30-50/s) which suggested that inactivation had been avoided. Further study showed that 20% glycerol could be replaced by equally high concentrations of compounds classified as osmolytes polyols (erythritol, xylitol, sorbitol), sugars (glucose, trehalose) and certain amino acids (glycine, proline, but not valine). The authors suggest that osmolytes may be used to fully stabilize chemiosmotic transporters during reconstitution.

  10. Solubilization of genistein in poly(oxyethylene) through eutectic crystal melting.

    PubMed

    Buddhiranon, Sasiwimon; Kyu, Thein

    2012-07-12

    Solid-liquid phase diagrams of binary crystalline blends of genistein with poly(ethylene oxide) (PEO) and poly(ethylene glycol) (PEG) were established experimentally and theoretically based on the combined Flory-Huggins free energy of liquid-liquid phase separation and the phase field free energy pertaining to crystal solidification. The liquidus lines obtained self-consistently were found to agree well with trends of depressed crystal melting transitions in genistein/PEO and genistein/PEG blends, exhibiting eutectic phase behavior. Of particular importance is the lowering of the eutectic temperature of the genistein/PEO blend by about 60 °C upon switching to the genistein/PEG system. The occurrence of interspecies hydrogen bonding between genistein molecules and both PEO and PEG chains, albeit weak, was noticed by Fourier transform infrared spectroscopy. The improved solubility of genistein in PEG can be attributed not only to lowering of the molecular weight of PEG utilized, but also to its terminal hydroxyl groups. This eutectic melting approach by PEG solvent is sufficiently effective in solubilizing genistein crystals that development of genistein-containing drugs might be feasible for injection and/or oral administration.

  11. Properties of alkali-solubilized collagen solution crosslinked by N-hydroxysuccinimide activated adipic acid

    NASA Astrophysics Data System (ADS)

    Chen, Yihui; Zhang, Min; Liu, Wentao; Li, Guoying

    2011-03-01

    The effect of N-hydroxysuccinimide activated adipic acid (NHS-AA) on the properties of alkali-solubilized collagen solutions was examined. The residual amino group content in crosslinked collagen, determined by trinitrobenzensulfonic acid (TNBS) assay, was decreased with increasing NHS-AA concentration. The results from differential scanning calorimeter (DSC) indicated that the maximum denaturation temperature ( T d) of crosslinked collagen solution was about 4.2°C higher than that of un-crosslinked collagen solution (36.6°C). Moreover, the values of storage modulus ( G'), loss modulus ( G″) and complex viscosity ( η*), obtained by means of dynamic frequency sweeps, were increased as NHS-AA concentration added up to 1.5 mM, and then decreased slightly when further increased NHS-AA concentration. Besides, for collagen solution crosslinked with 1.5 mM NHS-AA, dynamic denaturation temperature ( T dd) was about 1.1°C lower than T d (40.8°C), and the Arrhenius-type time-temperature superposition (TTS) principle was applied to yield the activation energy to be 474.4 kJmol-1.

  12. Optimized expression, solubilization and purification of nuclear inclusion protein b of cardamom mosaic virus.

    PubMed

    Jebasingh, T; Jacob, T; Shah, M; Das, D; Krishnaswamy, S; Usha, R

    2008-04-01

    All RNA viruses encode an RNA-dependent RNA polymerase (RdRP) that is required for replication of the viral genome. Nuclear inclusion b (NIb) gene codes for the RdRp in Potyviridae viruses. In this study, expression, solubilization and purification of NIb protein of Cardamom mosaic virus (CdMV) is reported. The objective of the present study was to express and purify the NIb protein of CdMV on a large scale for structural characterization, as the structure of the RdRp from a plant virus is yet to be determined. However, the expression of NIb protein with hexa-histidine tag in Escherichia coli led to insoluble aggregates. Out of all the approaches [making truncated versions to reduce the size of protein; replacing an amino acid residue likely to be involved in hydrophobic intermolecular interactions with a hydrophilic one; expressing the protein along with chaperones; expression in Origami cells for proper disulphide bond formation, in E. coli as a fusion with maltose-binding protein (MBP) and in Nicotiana tabacum] to obtain the RdRp in a soluble form, only expression in E. coli as a fusion with MBP and its expression in N. tabacum were successful. The NIb expressed in plant or as a fusion with MBP in E. coli can be scaled up for further work.

  13. Oxidative derivatization and solubilization of coal. Final report. Period: October 1, 1986 - April 30, 1988

    SciTech Connect

    Schulz, J.G.; Porowski, E.N.; Straub, A.M.

    1988-05-01

    We investigated the solubilization of coal by oxidative means to produce motor fuels. Nitric acid was used in the first of two approaches taken to cleave aliphatic linkages in coal and reduce the size of its macrostructure. Mild conditions, with temperatures up to a maximum of 75 C, and nitric acid concentrations below 20% by weight, characterize this process. The solid product, obtained in high yields, is soluble in polar organic solvents. Lower alcohols, methanol in particular, are of interest as carrier solvents in diesel fuel applications. Coals investigated were New York State peat, Wyodak subbituminous coal, North Dakota lignite, and Illinois No. 6 bituminous coal. The lower tank coals were easily converted and appear well suited to the process, while the bituminous Illinois No. 6 and Pitt Seam coals were unreactive. We concentrated our efforts on Wyodak coal and North Dakota lignite. Reaction conditions with regards to temperature, acid concentration, and time were optimized to obtain high product selectivity at maximum conversion. A continuous process scheme was developed for single pass coal conversions of about 50% to methanol-soluble product.

  14. Strategy for large scale solubilization of coal-characterization of neurospora protein and gene

    SciTech Connect

    Patel, A.; Chen, Y.P.; Mishra, N.C.

    1995-12-31

    Coal represents an important source of energy. Its utilization for generating energy has been offset by environmental problem that it creates by the release of SOx and NOx, which are major causes of acid rain and deforestation. Some of these problems can be tackled by the use of industrial scrubbers. However, a biotechnological approach to these problems may prove more efficient and environment friendly. We have employed certain genetically characterized fungi for the biosolubilization of coal in order to yield chemicals that can be converted into utilizable energy and can be rendered free of SOx and NOx at the source. Here we describe the purification of a protein which is responsible for the biodegradation of low rank coal both in vivo and in vitro. We also report the characterization of the biochemical nature of the coal derived products obtained after the biosolubilization of coal by this protein in vivo and in, vitro. Identification and characterization of this fungal protein is expected to help the cloning of the gene encoding this protein which is needed to construct a super strain of Neurospora capable of large scale solubilization of coal.

  15. Solubilization of nerve growth factor receptors of rabbit superior cervical ganglia.

    PubMed

    Banerjee, S P; Cuatrecasas, P; Snyder, S H

    1976-09-25

    Nerve growth factor (NGF) receptors of rabbit superior cervical ganglia can be solubilized by treatment with detergents and readily assayed in the soluble state. Triton X-100 and deoxycholate reduce specific binding of NGF to ganglia membranes. In membranes treated with Triton X-100 (0.5 to 2.0%) the reduction in NGF binding by membranes is accompanied by a corresponding increase in binding in the supernatant fluid. NGF binding in soluble preparations can be rapidly assayed by precipitating NGF bound to receptors with polyethylene glycol under conditions in which unbound NGF is not precipitated. NGF binding to soluble preparations is saturable whether evaluated by the binding of 125I-NGF or by diluting 125I-NGF with native NGF. Using both techniques, the dissociation constant for NGF binding to soluble receptors is about 0.2 nM, the same as its dissociation constant from receptor sites in intact membranes. NGF binding to soluble receptors displays a high degree of peptide specificity, similar to receptor sites in intact membranes of superior cervical ganglia. A method of labeling NGF with 125I-3(4-hydroxyphenyl) propionic acid N-hydroxysuccinimide ester is described which leads to binding properties that are superior to those obtained with previously described 125I-NGF preparations.

  16. Rheological behavior of acylated pepsin-solubilized collagen solutions: Effects of concentration

    NASA Astrophysics Data System (ADS)

    Li, Conghu; Duan, Lian; Tian, Zhenhua; Liu, Wentao; Li, Guoying; Huang, Xiaoping

    2015-11-01

    Effects of concentration on the rheological behavior of acylated pepsin-solubilized collagen solutions were investigated by steady shear tests, dynamic frequency sweep, creep tests and thixotropic loop measurements in this paper. The results showed that both acylated collagen and native collagen solutions exhibited the typical pseudoplastic behavior and displayed shear thinned behavior with the increase of shear rate. With the increase of acylated collagen concentrations from 5 to 10 mg/mL, shear viscosity, elasticity modulus ( G'), viscous modulus ( G″), complex viscosity ( η*), and the ability to resist deformation increased due to the physical entanglement, whilst loss tangent (tan δ) decreased. Additionally, with the increase of acylated collagen concentrations, the area of thixotropic loop increased from 6.94 to 44.40 watts/m3, indicating that the thixotropy of acylated collagen increased. Compared with native collagen solution, acylated collagen solution had stronger shear viscosity, η*, thixotropy, and ability to resist deformation. Furthermore, Power law model, Carreau model, Cross model, Leonov model and Burger model, were suitable for the fitting of the experimental data.

  17. Topical application of solubilized Reseda luteola extract reduces ultraviolet B-induced inflammation in vivo.

    PubMed

    Casetti, F; Jung, W; Wölfle, U; Reuter, J; Neumann, K; Gilb, B; Wähling, A; Wagner, S; Merfort, I; Schempp, C M

    2009-09-04

    We investigated the skin tolerance and anti-inflammatory potential of a nanoparticular solubilisate of a luteolin-rich Reseda extract (s-RE) in two independent studies in vivo. Reseda luteola extract containing 40% flavonoids was solubilized with polysorbate, resulting in product micelles with a diameter of 10 (+/-1.5)nm. Standardized inflammation was induced by irradiating test areas on the back of healthy volunteers with defined doses of ultraviolet B (UVB). In the first study different concentrations of s-RE were tested in 10 volunteers to evaluate dose-dependency of anti-inflammatory effects of s-RE. In the second randomized, double-blind, placebo-controlled study a defined concentration of s-RE (2.5%w/w) was tested in 40 volunteers in comparison to the vehicle (glycerol) and hydrocortisone (1%w/w). s-RE dose-dependently reduced UVB-induced erythema when applied 30 min before irradiation. To a lesser extent, topical application of s-RE after irradiation also reduced UVB-induced erythema. s-RE was as effective as hydrocortisone, whereas the vehicle had no effect. Occlusive application of s-RE on non-irradiated test sites did not cause any skin irritation. Due to excellent skin tolerance combined with potent anti-inflammatory properties s-RE bears potential especially for the prevention but also for the treatment of inflammatory skin conditions such as UV-induced erythema.

  18. Solubilization of blood meal to be used as a liquid fertilizer.

    PubMed

    Chan, Winnie I; Lo, Kwang V; Liao, Ping H

    2007-05-01

    The solubilization of blood meal by means of the microwave-hydrogen peroxide enhanced advanced-oxidation process (MW/H(2)O(2)-AOP) was studied. It was found that over the treatment temperature range of 60 to 120 degrees C, solids particle reduction, ammonia and orthophosphate production could be achieved by this process. Large protein molecules were broken down into intermediate compounds with low molecule weights, ammonia and nitrate. Intermediate compounds, such as peptides and amino acids, can also be easily converted to nitrogenous nutrients for plant growth by bacteria. Soluble nitrogen content increased with an increase in microwave heating temperature when acid was added; significant amounts of ammonia were obtained at higher temperatures. Nitrate decreased in concentration with an increase of treatment temperature. Orthophosphate concentrations increased after the advanced-oxidation process (AOP) treatments, with and without acid addition; but were more pronounced with acid addition. Maximum solubility of chemical oxygen demand (COD) occurred at 80 degrees C. Without the addition of acid, soluble COD decreased due to protein denaturation and coagulation out of the solution.

  19. Cyclodextrins in pharmaceutical formulations II: solubilization, binding constant, and complexation efficiency.

    PubMed

    Jambhekar, Sunil S; Breen, Philip

    2016-02-01

    Cyclodextrins are cyclic oligosaccharides that have been recognized as pharmaceutical adjuvants for the past 20 years. The molecular structure of these glucose derivatives, which approximates a truncated cone, bucket, or torus, generates a hydrophilic exterior surface and a nonpolar interior cavity. Cyclodextrins can interact with appropriately sized drug molecules to yield an inclusion complex. These noncovalent inclusion complexes offer a variety of advantages over noncomplexed forms of a drug. Cyclodextrins are carbohydrates that are primarily used to enhance the aqueous solubility, physical chemical stability, and bioavailability of drugs. Their other applications include preventing drug-drug interactions, converting liquid drugs into microcrystalline powders, minimizing gastrointestinal and ocular irritation, and reducing or eliminating unpleasant taste and smell. Here, we focus on the solubilization of drugs by complexation, and discuss the determination and significance of binding constants for cyclodextrin complexes, and the determination of complexation efficiency and factors that influence it. We also make some general observations on cyclodextrin complexation and the use of cyclodextrins in solid, as well as parenteral, dosage forms.

  20. Solubilization of the O2(-)-forming activity responsible for the respiratory burst in human neutrophils.

    PubMed

    Gabig, T G; Kipnes, R S; Babior, B M

    1978-10-10

    On exposure to suitable activating agents, neutrophils sharply alter their oxygen metabolism, showing large increases in oxygen uptake, O2 and H2O2 production, and glucose consumption via the hexose monophosphate shunt. These metabolic alterations, which together are designated the "respiratory burst," are due to the activation of a system which catalyzes the reaction: 2O2 + NADPH leads to 2O2(-) + NADP. This O2(-)-forming system is found in a particulate fraction isolated from neutrophils which had been activated with opsonized zymosan. When these particles were treated with detergent under suitable conditions, the O2(-)-forming activity was released in a form which passed through a membrane filter capable of retaining species of Mr greater than 3000,000. Soluble O2(-)-forming activity was obtained from normal activated neutrophils, but not from normal resting neutrophils or from activated neutrophils obtained from patients with chronic granulomatous disease, an inherited condition in which the respiratory burst is defective. O2(-)production by the soluble system required a reduced pyridine nucleotide as electron donor, and showed a quadratic dependence on the concentration of the solubilized preparation.

  1. Titration of fatty acids solubilized in cationic and anionic micelles. Calorimetry and thermodynamic modeling.

    PubMed

    Söderman, Olle; Jönsson, Bengt; Olofsson, Gerd

    2006-02-23

    The electrostatic properties of charged surfactant micelles are investigated through titrations of fatty acid probes solubilized in the micelles. The titration process is followed by means of calorimetric measurements and by determining the pH values as a function of added base. This approach yields a complete thermodynamic description of the titration process. In particular, we find that the process is endothermic at 298 K. This is contrary to the titration of carboxylic acids in water, where DeltaH is approximately 0. To identify the main effect underlying the difference in DeltaH between titration in a micelle and water, a thermodynamic model has been developed which focuses on the transfer properties of charged and uncharged species from bulk water to the surface of a micelle and which incorporates a dielectric discontinuity at the micellar surface. The model relies on the use of the Poisson-Boltzmann equation which is solved using a finite element method. Experimental results and the model calculations imply that the dielectric discontinuity at (or near) the micellar surface plays a major role and hence must be included when analyzing the titration behavior of an acid functionality at the surface of a charged micelle.

  2. Complete solubilization of formalin-fixed, paraffin-embedded tissue may improve proteomic studies.

    PubMed

    Shi, Shan-Rong; Taylor, Clive R; Fowler, Carol B; Mason, Jeffrey T

    2013-04-01

    Tissue-based proteomic approaches (tissue proteomics) are essential for discovering and evaluating biomarkers for personalized medicine. In any proteomics study, the most critical issue is sample extraction and preparation. This problem is especially difficult when recovering proteins from formalin-fixed, paraffin-embedded (FFPE) tissue sections. However, improving and standardizing protein extraction from FFPE tissue is a critical need because of the millions of archival FFPE tissues available in tissue banks worldwide. Recent progress in the application of heat-induced antigen retrieval principles for protein extraction from FFPE tissue has resulted in a number of published FFPE tissue proteomics studies. However, there is currently no consensus on the optimal protocol for protein extraction from FFPE tissue or accepted standards for quantitative evaluation of the extracts. Standardization is critical to ensure the accurate evaluation of FFPE protein extracts by proteomic methods such as reverse phase protein arrays, which is now in clinical use. In our view, complete solubilization of FFPE tissue samples is the best way to achieve the goal of standardizing the recovery of proteins from FFPE tissues. However, further studies are recommended to develop standardized protein extraction methods to ensure quantitative and qualitative reproducibility in the recovery of proteins from FFPE tissues.

  3. Surface solubilization of phenanthrene by surfactant sorbed on soils with different organic matter contents.

    PubMed

    Ahn, Chi Kyu; Woo, Seung Han; Park, Jong Moon

    2010-05-15

    The effect of sorbed surfactant on the distribution of hydrophobic organic compounds (HOCs) during soil washing was investigated using a mathematical model. Phenanthrene (PHE) as an HOC and Triton X-100 (TX100) as a nonionic surfactant were used with two soils with low (SS) and high (BS) organic matter contents. The available carbon fraction (f(A,soil)(*)) after surfactant sorption was determined from surfactant coverage by measuring soil surface area using a methylene blue method. The sorbed surfactant was greatly effective as a sorbent for PHE, with an effectiveness factor (epsilon(soil)) in the range of 10.9-117.2 for SS and 39.7-121.3 for BS. Surface molar solubilization ratio (MSR(s)) and epsilon(soil) decreased with increasing TX100 dose. The MSR(s) decrement was lower for BS than for SS probably due to stronger affinity of PHE on organic matter in BS than in SS, which cause lower efficiency of soil washing than estimated by intrinsic sorption of PHE. These results suggest that soil washing in the field using surfactant for soils with high organic matter contents may give much lower efficiency than expected due to additional adsorption of HOC onto sorbed surfactant.

  4. Fractionation of alkali-solubilized hemicelluloses from delignified Populus gansuensis: structure and properties.

    PubMed

    Peng, Feng; Ren, Jun-Li; Xu, Feng; Bian, Jing; Peng, Pai; Sun, Run-Cang

    2010-05-12

    The dewaxed cell walls of Populus gansuensis were delignified with NaClO(2) and then sequentially extracted with 0.25, 0.5, and 1.0 M KOH under a solid to liquid ratio of 1: 25 (g mL(-1)) at 25 degrees C for 10 h. The successive treatments together resulted in the dissolution of 83.7% of original hemicelluloses. The solubilized hemicellulosic fractions were further fractionated into six hemicellulosic subfractions by an iodine-complex precipitation technique. Their chemical and physical characteristics were determined by HPAEC, GPC, FT-IR, and (1)H and (13)C NMR spectroscopy. Neutral sugar composition and molecular weight analysis showed that, for each extract, the hemicellulosic subfractions that precipitated with aqueous potassium iodide-iodine had lower overall uronic acid/xylose (Uro/Xyl) ratios and higher molecular weights (M(w)) than those remaining in the solution. FT-IR, (1)H, and (13)C NMR spectroscopy analysis indicated that the alkali-soluble hemicelluloses of Populus gansuensis had a structure composed of the (1 --> 4)-linked beta-D-xylopyranosyl backbone with 4-O-methyl-alpha-D-glucuronic acid attached to O-2 of the xylose residues.

  5. Formulation and Evaluation of Aceclofenac Injection Made by Mixed Hydrotropic Solubilization Technique

    PubMed Central

    Kumar Maheshwari, Rajesh; Indurkhya, Arpna

    2010-01-01

    Aceclofenac is a non-steroidal anti-inflammatory drug (NSAID) that exhibits analgesic, antipyretic and anti-inflammatory activities. It is practically insoluble in water. The effect of hydrotropes such as urea and sodium citrate and blends (urea + sodium citrate) on the solubility of aceclofenac was investigated. The enhancement in the solubility of aceclofenac was more than 5 and 25 folds in 30% sodium citrate solution and 30% urea solution, respectively, as compared to its solubility in distilled water. The enhancement in the solubility of aceclofenac in a mixed hydrotropic solution containing ≥ 20% urea and 10% sodium citrate solution was more than 250 folds (compared to its solubility in distilled water). This proved a synergistic enhancement in solubility of a poorly water- soluble drug due to mixed hydrotropy. Synergistic combination of hydrotropic agents can minimize the amount of hydrotropic agents employed, minimizing the chances of their toxicities. Aqueous injection of aceclofenac, using the mixed hydrotropic solubilization technique, was developed and by using the lyophilization method, the problem of inadequate stability of aceclofenac in aqueous solution was overcome. The developed formulation was studied for physical and chemical stability. PMID:24363732

  6. [Characterization of growth-promoting rhizobacteria in Eucalyptus nitens seedlings].

    PubMed

    Angulo, Violeta C; Sanfuentes, Eugenio A; Rodríguez, Francisco; Sossa, Katherine E

    2014-01-01

    Rhizospheric and endophytic bacteria were isolated from the rizosphere and root tissue of Eucalyptus nitens. The objective of this work was to evaluate their capacity to promote growth in seedlings of the same species under greenhouse conditions. The isolates that improved seedling growth were identified and characterized by their capacity to produce indoleacetic acid (IAA), solubilize phosphates and increase 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity. One hundred and five morphologically different strains were isolated, 15 of which promoted E. nitens seedling growth, significantly increasing the height (50%), root length (45%) as well as the aerial and root dry weight (142% and 135% respectively) of the plants. Bacteria belonged to the genus Arthrobacter, Lysinibacillus, Rahnella and Bacillus. Isolates A. phenanthrenivorans 21 and B. cereus 113 improved 3.15 times the emergence of E. nitens after 12 days, compared to control samples. Among isolated R. aquatilis, 78 showed the highest production of IAA (97.5±2.87 μg/ml) in the presence of tryptophan and the highest solubilizer index (2.4) for phosphorus, while B. amyloliquefaciens 60 isolate was positive for ACC deaminase activity. Our results reveal the potential of the studied rhizobacteria as promoters of emergence and seedling growth of E. nitens, and their possible use as PGPR inoculants, since they have more than one mechanism associated with plant growth promotion.

  7. Microbial safety in space

    NASA Astrophysics Data System (ADS)

    Krooneman, Janneke; Harmsen, Hermie; Landini, Paolo; Zinn, Manfred; Munaut, Françoise; van der Meer, Walter; Beimfohr, Claudia; Reichert, Bas; Preuß, Andrea

    2005-10-01

    Microbial hygiene is important in our daily lives; preventing and combating microbial infections is increasingly important in society. In hospitals, strict monitoring and control is exercised for people and infrastructure alike. In modern buildings, air-conditioning system are screened for harmful bacteria such as Legionella. More recently, concerns about SARS (virus) and anthrax (bacteria) have added pressure on the scientific community to come up with adequate monitoring and control techniques to assure microbial hygiene. Additionally, the use of biotechnological recycling and cleaning processes for sustainability brings the need for reliable monitoring tools and preventive or riks-reducing strategies. In the manned space environment, similar problems need to be solved and efforts have already been made to study the behaviour of micro-organisms and microbial hygiene onboard space stations.

  8. Microbial Source Tracking

    EPA Science Inventory

    Bacterial indicators of fecal contamination provide the basis for assessing the microbial quality of environmental waters. While the indicator concept has overall helped reduce waterborne outbreaks in recreational waters, the public health value of currently used indicator bacter...

  9. Peculiar mechanism of solubilization of a sparingly water soluble drug into polymeric micelles. Kinetic and equilibrium studies.

    PubMed

    Turco Liveri, Maria Liria; Licciardi, Mariano; Sciascia, Luciana; Giammona, Gaetano; Cavallaro, Gennara

    2012-04-26

    Complementary kinetic and equilibrium studies on the solubilization process of the sparingly water soluble tamoxifen (TAM) drug in polymeric aqueous solutions have been performed by using the spectrophotometric method. In particular, the amphiphilic copolymers obtained by derivatization of polymeric chain of poly(N-2-hydroxyethyl)-dl-aspartamide, PHEA, with poly(ethylene glycol)s, PEG (2000 or 5000 Da), and/or hexadecylamine chain, C16, namely PHEA-PEG2000-C16, PHEA-PEG5000-C16, PHEA-C16, have been employed. Preliminary to the kinetic and equilibrium data quantitative treatment, the molar absorption coefficient of TAM in polymeric micelle aqueous solution has been determined. By these studies the solubization sites of TAM into the polymeric micelles have been determined and the solubilization mechanism has been elucidated through a nonconventional approach by considering the TAM partitioned between three pseudophases, i.e., the aqueous pseudophase, the hydrophilic corona, and the hydrophobic core. The simultaneous solution of the rate laws associated with each step of the proposed mechanism allowed the calculation of the rate constants associated with the involved processes, the values of which are independent of both the copolymer concentration and nature, with the exception of the rate of the TAM transfer from the corona to the core. This has been attributed to the steric barrier, represented by the corona, which hampers the solubilization into the core. The binding constant values of the TAM to the hydrophilic corona of the polymeric micelles, calculated through the quantitative analysis of the equilibrium data, depend on the thickness of the hydrophilic headgroup, while those of the hydrophobic core are almost independent of the copolymer type. Further confirmation to the proposed solubilization mechanism has been provided by performing the kinetic and equilibrium measurements in the presence of PHEA-PEG2000 and PHEA-PEG5000 copolymers.

  10. Gelation properties of spent duck meat surimi-like material produced using acid-alkaline solubilization methods.

    PubMed

    Nurkhoeriyati, T; Huda, N; Ahmad, R

    2011-01-01

    The gelation properties of spent duck meat surimi-like material produced using acid solubilization (ACS) or alkaline solubilization (ALS) were studied and compared with conventionally processed (CON) surimi-like material. The ACS process yielded the highest protein recovery (P < 0.05). The ALS process generated the highest lipid reduction, and the CON process yielded the lowest reduction (P < 0.05). Surimi-like material produced by the CON process had the highest gel strength, salt extractable protein (SEP), and water holding capacity (WHC), followed by materials produced via the ALS and ACS processes and untreated duck meat (P < 0.05). The material produced by the CON process also had the highest cohesiveness, hardness, and gumminess values and the lowest springiness value. Material produced by the ACS and ALS processes had higher whiteness values than untreated duck meat gels and gels produced by the CON method (P < 0.05). Surimi-like material produced using the ACS and CON processes had significantly higher myoglobin removal (P < 0.05) than that produced by the ALS method and untreated duck meat. Among all surimi-like materials, the highest Ca(2+)-ATPase activity was found in conventionally produced gels (P < 0.05). This suggests that protein oxidation was induced by acid-alkaline solubilization. The gels produced by ALS had a significantly lower (P < 0.05) total SH content than the other samples. This result showed that the acid-alkaline solubilization clearly improved gelation and color properties of spent duck and possibly applied for other high fat raw material.

  11. Stress tolerance and genetic variability of phosphate-solubilizing fluorescent Pseudomonas from the cold deserts of the trans-Himalayas.

    PubMed

    Vyas, Pratibha; Rahi, Praveen; Gulati, Arvind

    2009-08-01

    Nineteen efficient phosphate-solubilizing fluorescent Pseudomonas from the cold deserts of the trans-Himalayas were screened for stress tolerance against temperature, alkalinity, salinity, calcium salts, and desiccation. Phylogenetic analysis based on 16S rRNA gene sequencing placed these bacteria under three groups with fourteen strains in Group I including Pseudomonas trivialis and P. poae, two strains in Group II together with Pseudomonas kilonensis and P. corrugata, and three strains in Group III along with Pseudomonas jessenii and P. moraviensis. Genetic diversity assessed by ERIC and BOX-PCR revealed variability among strains belonging to the same phylogenetic groups. Cluster analysis based on the growth characteristics under regimes of different stress levels placed the strains into three distinct clusters displaying no correlation to their phylogenetic groups. Stress-tolerant strains differed in the level of decline in phosphate solubilization under increasing intensity of various stress parameters. The highest decrease occurred with 5% CaCO(3,) followed by 2.5% CaCO(3), pH 11, 5% NaCl, temperature of 37 degrees C, 40% PEG, 5% CaSO(4), 2.5% NaCl, 2.5% CaSO(4), pH 9 and temperature of 15 degrees C. Two strains belonging to Phylogenetic Group I exhibited higher phosphate solubilization at lower temperature. The results revealed that stress-tolerance ability was not limited to any particular phylogenetic group. Knowledge about the genetic variants of phosphate-solubilizing fluorescent Pseudomonas with potential for tolerance to desiccation, alkalinity, temperature, and salinity could be useful in understanding their ecological role under stressful environments of low phosphate availability.

  12. Solubilization and preformulation of poorly water soluble and hydrolysis susceptible N-epoxymethyl-1,8-naphthalimide (ENA) compound.

    PubMed

    Dong, Yuancai; Ng, Wai Kiong; Surana, Uttam; Tan, Reginald B H

    2008-05-22

    N-Epoxymethyl-1,8-naphthalimide (ENA) is a novel antiproliferative drug candidate with potent anticancer and antifungal activity. It has an aqueous solubility of 0.0116mg/mL and also exhibits hydrolytic instability with a first-order hydrolysis rate of 0.051 h(-1). The present preformulation study aimed to characterize the physicochemical properties of ENA and develop an early injectable solution formulation for preclinical studies. To minimize hydrolysis, ENA is proposed to be formulated as either lyophilized powders or nonaqueous solutions followed by solubilization/reconstitution prior to administration. ENA solubilization was investigated in both aqueous media (by cosolvency, micellization and complexation) and nonaqueous solutions (mixture of Cremophor EL and ethanol). It is found that none of the solubilization techniques in aqueous media could increase ENA solubility to a desired level of several hundreds microg/mL at pharmaceutically acceptable excipient concentrations (< or =10%). In contrast, a combination of 70% Cremophor EL and 30% ethanol (v/v) proved effective in solubilizing ENA at 4 mg/mL, which exhibited good physical and chemical stability on storage at both 4 degrees C and room temperature over 4 months. No precipitation was observed upon 5-20 times dilution by the saline; in addition, less than 5% of ENA was hydrolyzed in 4h for the saline-diluted aqueous solutions. This nonaqueous ENA formulation is thus proposed for further preclinical studies, which can be reconstituted, prior to administration, by the 5-20 times infusion fluids (saline, 5% dextrose, etc.) to the desired drug dosing concentration at the acceptable excipient level. The approach used in this work could serve as a useful reference in formulating nonpolar drugs with hydrolytic instability.

  13. Pyrosequencing Based Microbial Community Analysis of Stabilized Mine Soils

    NASA Astrophysics Data System (ADS)

    Park, J. E.; Lee, B. T.; Son, A.

    2015-12-01

    Heavy metals leached from exhausted mines have been causing severe environmental problems in nearby soils and groundwater. Environmental mitigation was performed based on the heavy metal stabilization using Calcite and steel slag in Korea. Since the soil stabilization only temporarily immobilizes the contaminants to soil matrix, the potential risk of re-leaching heavy metal still exists. Therefore the follow-up management of stabilized soils and the corresponding evaluation methods are required to avoid the consequent contamination from the stabilized soils. In this study, microbial community analysis using pyrosequencing was performed for assessing the potential leaching of the stabilized soils. As a result of rarefaction curve and Chao1 and Shannon indices, the stabilized soil has shown lower richness and diversity as compared to non-contaminated negative control. At the phyla level, as the degree of contamination increases, most of phyla decreased with only exception of increased proteobacteria. Among proteobacteria, gamma-proteobacteria increased against the heavy metal contamination. At the species level, Methylobacter tundripaludum of gamma-proteobacteria showed the highest relative portion of microbial community, indicating that methanotrophs may play an important role in either solubilization or immobilization of heavy metals in stabilized soils.

  14. Benzo[a]pyrene and zinc solubilization by digestive fluids of benthic invertebrates--a cross-phyletic study.

    PubMed

    Mayer, L M; Weston, D P; Bock, M J

    2001-09-01

    Contaminant bioavailability via digestive exposure was examined for 18 species of marine benthic invertebrates, using incubation of digestive fluids with sediments that were spiked with either radiolabeled benzo-[a]-pyrene (BaP) or zinc. Interphyletic trends in contaminant solubilization were compared with measures of digestive biochemistry, including enzyme activities, surfactancy, pH, and fluid phase organic carbon, amino acids, and lipids. Contaminant solubilization ranged from values equal to that of a seawater control to as much as an order of magnitude higher but were lower than those obtained with commonly used chemical extractants. Digestive fluids from echinoderms and a cnidarian tended to be relatively weak, those from polychaetes and echiurans were relatively strong, and those from taxa such as sipunculans and mollusks were intermediate. These trends correlated strongly with concentrations or activities of digestive biochemicals but not with pH. These correlations are consistent with previous work on mechanisms of digestive solubilization of polycyclic aromatic hydrocarbons (PAH) and metals, though strong covariance among digestive parameters does not allow this approach to be used for identification of specific mechanism(s).

  15. Characterization and purification of the detergent solubilized atrial natriuretic peptide receptor from bovine aortic smooth muscle cells

    SciTech Connect

    Schenk, D.; Phelps, M.; Scarborough, R.; Johnson, K.; Lewicki, J.

    1986-03-01

    A protein has been purified from total homogenates of cultured vascular bovine smooth muscle cells with properties indicative of the receptor for atrial natriuretic peptide (ANP). Specific /sup 125/I-ANP binding activity was solubilized quantitatively from smooth muscle cell membranes with a purified component of Triton X-100. Equilibrium binding studies of the solubilized ANP receptor reveal by Scatchard analysis a single class of binding sites with a K/sub d/ = 1.77 x 10/sup -10/ moles /sup 125/I-ANP/1 and B/sub max/ = 34.6 pmol/mg protein. The ANP receptor solubilized in this manner is stable for greater than or equal to 2 months at -70/sup 0/C. Studies investigating the ANP receptor show that it binds to wheat germ agglutinin and to CM-cellulose at pH 4.1 but not at pH 6.5. These findings imply that the ANP receptor is a neutral to mildly basic glycoprotein. Further purification studies involving affinity chromatography with ANP-Sepharose result in a 500-fold purification and reveal a single protein with a molecular mass of 58,700 daltons as determined by SDS-polyacrylamide gel electrophoresis. The size of this protein is in good agreement with that of an ANP receptor previously identified in intact smooth muscle cells by crosslinking studies with /sup 125/I-ANP.

  16. Estimation of cholesterol solubilization by a mixed micelle binding model in aqueous tauroursodeoxycholate:lecithin:cholesterol solutions.

    PubMed

    Higuchi, William I; Tzeng, Chinn-Shin; Chang, Shyh-Jye; Chiang, Huey-Jenn; Liu, Chen-Lun

    2008-01-01

    In order to interpret the clinical efficacy of conjugated ursodeoxycholate (UDC) in cholesterol (Ch) gallstone patients, the Ch solubilization in mixed micelles in 40:40:32 mM tauroursodeoxycholate (TUDC):taurochenodeoxycholate (TCDC):lecithin (L) and 80:32 mM TUDC:L systems was estimated by using a model of Ch binding to mixed micelles. The Ch solubilization limit in mixed TUDC:L micelles was found to be higher than that in mixed TUDC:TCDC:L micelles. In the 80:32 mM TUDC:L system, the dissolution of the Ch pellet decreased after vesicles (liposomes) formed on the surface of the Ch pellet whereas the dissolution of microcrystalline Ch was rapid before and after vesicle formation in the solution, indicating that the total surface area of solid Ch exposed to the solution may be another important factor in inducing the dissolution of Ch gallstones. These phenomena suggest that although vesicles, occasionally formed in the bile of patients under the therapy of conjugated UDC, make a contribution to the solubilization of Ch gallstones, the model of Ch binding to mixed TUDC:L micelles can be used to estimate Ch solubility in TUDC:L system.

  17. Solubilized auxin-binding protein : Subcellular localization and regulation by a soluble factor from homogenates of corn shoots.

    PubMed

    Cross, J W; Briggs, W R

    1979-01-01

    Discontinuous sucrose gradient fractionations indicate that the high-affinity auxin binding protein which can be solubilized from the microsomes of coleoptiles and primary leaves of Zea mays L. seedlings is probably located in the endoplasmic reticulum (ER). Since aromatic hydroxylations are enzymatic activities typical of the ER of plant cells, we have examined the effects of several electron-transport inhibitors on the binding of 1-naphthylacetic acid (NAA). NaN3 strongly inhibits this binding, but KCN and CO do not. Trans-cinnamic acid and trans-p-coumaric acid, which are the substrates of ER hydroxylase activities in plants (but which are themselves not auxins), also inhibit this binding. Supernatant fractions from corn shoots contain factors inhibitory to the binding of NAA to the intact membranes and solubilized Site I auxin-binding protein. Here we show that these factors are competitive inhibitors of the binding of [(14)C]NAA but do not change the apparent affinity of the protein for indoleacetic acid, 2,4-dichlorophenoxyacetic acid or naphthoxyacetic acid. Several tissues were assayed for factors inhibitory to auxin binding to the solubilized protein, but only supernants from corn shoots were markedly inhibitory at low concentrations.

  18. Microbial Life in Soil - Linking Biophysical Models with Observations

    NASA Astrophysics Data System (ADS)

    Or, D.; Tecon, R.; Ebrahimi, A.; Kleyer, H.; Ilie, O.; Wang, G.

    2014-12-01

    Microbial life in soil occurs within fragmented aquatic habitats in complex pore spaces where motility is restricted to short hydration windows (e.g., following rainfall). The limited range of self-dispersion and physical confinement promote spatial association among trophically interdepended microbial species. Competition and preferences for different nutrient resources and byproducts and their diffusion require high level of spatial organization to sustain the functioning of multispecies communities. We report mechanistic modeling studies of competing multispecies microbial communities grown on hydrated surfaces and within artificial soil aggregates (represented by 3-D pore network). Results show how trophic dependencies and cell-level interactions within patchy diffusion fields promote spatial self-organization of motile microbial cells. The spontaneously forming patterns of segregated, yet coexisting species were robust to spatial heterogeneities and to temporal perturbations (hydration dynamics), and respond primarily to the type of trophic dependencies. Such spatially self-organized consortia may reflect ecological templates that optimize substrate utilization and could form the basic architecture for more permanent surface-attached microbial colonies. Hydration dynamics affect structure and spatial arrangement of aerobic and anaerobic microbial communities and their biogeochemical functions. Experiments with well-characterized artificial soil microbial assemblies grown on porous surfaces provide access to community dynamics during wetting and drying cycles detected through genetic fingerprinting. Experiments for visual observations of spatial associations of tagged bacterial species with known trophic dependencies on model porous surfaces are underway. Biophysical modeling provide a means for predicting hydration-mediated critical separation distances for activation of spatial self-organization. The study provides new modeling and observational tools that

  19. Microbial Life in Soil - Linking Biophysical Models with Observations

    NASA Astrophysics Data System (ADS)

    Or, Dani; Tecon, Robin; Ebrahimi, Ali; Kleyer, Hannah; Ilie, Olga; Wang, Gang

    2015-04-01

    Microbial life in soil occurs within fragmented aquatic habitats formed in complex pore spaces where motility is restricted to short hydration windows (e.g., following rainfall). The limited range of self-dispersion and physical confinement promote spatial association among trophically interdepended microbial species. Competition and preferences for different nutrient resources and byproducts and their diffusion require high level of spatial organization to sustain the functioning of multispecies communities. We report mechanistic modeling studies of competing multispecies microbial communities grown on hydrated surfaces and within artificial soil aggregates (represented by 3-D pore network). Results show how trophic dependencies and cell-level interactions within patchy diffusion fields promote spatial self-organization of motile microbial cells. The spontaneously forming patterns of segregated, yet coexisting species were robust to spatial heterogeneities and to temporal perturbations (hydration dynamics), and respond primarily to the type of trophic dependencies. Such spatially self-organized consortia may reflect ecological templates that optimize substrate utilization and could form the basic architecture for more permanent surface-attached microbial colonies. Hydration dynamics affect structure and spatial arrangement of aerobic and anaerobic microbial communities and their biogeochemical functions. Experiments with well-characterized artificial soil microbial assemblies grown on porous surfaces provide access to community dynamics during wetting and drying cycles detected through genetic fingerprinting. Experiments for visual observations of spatial associations of tagged bacterial species with known trophic dependencies on model porous surfaces are underway. Biophysical modeling provide a means for predicting hydration-mediated critical separation distances for activation of spatial self-organization. The study provides new modeling and observational tools

  20. Changes in labeling of soluble and solubilized rat brain proteins using (3H)-leucine as precursor during a learning experiment.

    PubMed

    Popov, N; Schulzeck, S; Schmidt, S; Matthies, H

    1975-01-01

    This paper deals with an electrophoretic study on soluble and solubilized rat brain proteins during a brightness discrimination. After intraventricular injection of L-[3H]-leucine the most pronounced increase in relative specific activity was found for several soluble acidic protein-band complexes as well as for solubilized slow-migrating non-myelin proteins obtained from hippocampus of trained animals over the data obtained for active and passive controls.