Science.gov

Sample records for compounds so-called microbial

  1. [Assessment of so called organic trace compounds in drinking water from the regulatory, health and aesthetic-quality points of view, with special consideration given to pharmaceuticals].

    PubMed

    Dieter, H H; Mückter, H

    2007-03-01

    More than 2500 chemically defined substances are approved as drugs in Germany. Unlike agricultural pesticides, these biologically active structures are not used in open environmental compartments and therefore their environmental toxicological data base is not nearly as complete. Nevertheless, some of them become environmental contaminants after their intended use. Therefore, from the viewpoint of environmental health protection, there are gaps in their health-related environmental risk assessment. Organic trace compounds that lack an adequate toxicological database, and their mixtures, in drinking water can be safely regulated and provisionally assessed by combining the "similar joint action" addition rule with the recommendation of the Federal Environment Agency of March 2003 "Assessing the presence of substances in drinking water without (adequate) toxicological database from the health point of view". The general precautionary value (Gesundheitlicher Orientierungswert GOW1=0.10 microg/l), which is a recommendation for weakly to not genotoxic compounds, re presents a workable compromise between preventive health protection, water management considerations and aesthetic quality claims (purity). Compliance with this value in the long term will only be possible if the chemical and biological degradation of pharmaceuticals and their metabolites in waste water and waste water treatment plants is effectively improved. Alternatively, there is the risk of drinking water degenerating into a sink for highly mobile, polar and persistent compounds. Their elimination at a stage as late as technical drinking water treatment would be neither close to the initial cause nor justifiable in terms of technical effectiveness. The risk assessment of their byproducts would give rise to further uncertainties. Possible conflicts with the therapeutic quality must be solved by developing substitute products which are environmentally sound.

  2. So-called Spontaneous Human Combustion.

    PubMed

    Levi-Faict, Thierry W; Quatrehomme, Gérald

    2011-09-01

    A well-documented case of so-called Spontaneous Human Combustion is reported. Review of the literature shows that these strange observations have been reported since the 17th century, even in famous novels. There are several main features that may lead to help the diagnosis: the vicinity of the body is intact or nearly intact, some parts of the body are turned into ashes (usually the middle third of the body), whereas other parts are intact or nearly intact, burning of the body usually occurs postmortem, the cause of death is usually natural, there is often (but not always) high concentrations of blood alcohol, there is a source of heat near the body. It is indispensable to rule out a homicide by the examination of the body in situ, the autopsy, the toxicological and histopathological samples, the arson assessment, and a thorough police inquiry.

  3. The So-Called 'Face on Mars'

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 13 April 2002) The Science The so called 'Face on Mars' can be seen slightly above center and to the right in this THEMIS visible image. This 3-km long knob, located near 10o N, 40o W (320o E), was first imaged by the Viking spacecraft in the 1970's and was seen by some to resemble a face carved into the rocks of Mars. Since that time the Mars Orbiter Camera on the Mars Global Surveyor spacecraft has provided detailed views of this hill that clearly show that it is a normal geologic feature with slopes and ridges carved by eons of wind and downslope motion due to gravity. A similar-size hill in Phoenix, Arizona resembles a camel lying on the ground, and Phoenicians whimsically refer to it as Camelback Mountain. Like the hills and knobs of Mars, however, Camelback Mountain was carved into its unusual shape by thousands of years of erosion. The THEMIS image provides a broad perspective of the landscape in this region, showing numerous knobs and hills that have been eroded into a remarkable array of different shapes. Many of these knobs, including the 'Face', have several flat ledges partway up the hill slopes. These ledges are made of more resistant layers of rock and are the last remnants of layers that once were continuous across this entire region. Erosion has completely removed these layers in most places, leaving behind only the small isolated hills and knobs seen today. Many of the hills and ridges in this area also show unusual deposits of material that occur preferentially on the cold, north-facing slopes. It has been suggested that these deposits were 'pasted' on the slopes, with the distinct, rounded boundary on their upslope edges being the highest remaining point of this pasted-on layer. In several locations, such as in the large knob directly south of the 'Face', these deposits occur at several different heights on the hill. This observation suggests the layer once draped the entire knob and has since been removed from all but the north

  4. [Once again the so-called Testament of Hippocrates].

    PubMed

    Sideras, Alexander

    2006-01-01

    This study is dealing with the so-called Testament of Hippocrates, a short ethic about the doctor's background, knowledge, character, appearance and behaviour towards the patient. Along with the three well-known Greek manuscripts the author is looking at two other by now unknown codices, so that the two Greek versions are accompanied by a third and larger version. After a careful consideration of the relations between the different versions he is discussing all readings of the codices explaining the terms within the background of the history of medicine. At the end he is presenting a reconstruction of the Greek original together with a German translation.

  5. Insight into the so-called spatial reciprocity

    NASA Astrophysics Data System (ADS)

    Wang, Zhen; Kokubo, Satoshi; Tanimoto, Jun; Fukuda, Eriko; Shigaki, Keizo

    2013-10-01

    Up to now, there have been a great number of studies that demonstrate the effect of spatial topology on the promotion of cooperation dynamics (namely, the so-called “spatial reciprocity”). However, most researchers probably attribute it to the positive assortment of strategies supported by spatial arrangement. In this paper, we analyze the time course of cooperation evolution under different evolution rules. Interestingly, a typical evolution process can be divided into two evident periods: the enduring (END) period and the expanding (EXP) period where the former features that cooperators try to endure defectors’ invasion and the latter shows that perfect C clusters fast expand their area. We find that the final cooperation level relies on two key factors: the formation of the perfect C cluster at the end of the END period and the expanding fashion of the perfect C cluster during the EXP period. For deterministic rule, the smooth expansion of C cluster boundaries enables cooperators to reach a dominant state, whereas, the rough boundaries for stochastic rule cannot provide a sufficient beneficial environment for the evolution of cooperation. Moreover, we show that expansion of the perfect C cluster is closely related to the cluster coefficient of interaction topology. To some extent, we present a viable method for understanding the spatial reciprocity mechanism in nature and hope that it will inspire further studies to resolve social dilemmas.

  6. The So-Called 'Face on Mars' in Infrared

    NASA Technical Reports Server (NTRS)

    2002-01-01

    [figure removed for brevity, see original site] (Released 24 July 2002) This set of THEMIS infrared images shows the so-called 'face on Mars' landform located in the northern plains of Mars near 40o N, 10o W (350 o E). The 'face' is located near the center of the image approximately 1/6 of the way down from the top, and is one of a large number of knobs, mesas, hills, and buttes that are visible in this THEMIS image. The THEMIS infrared camera has ten different filters between 6.2 and 15 micrometers - nine view the surface and one views the CO2 atmosphere. The calibrated and geometrically projected data from all of the nine surface-viewing filters are shown in this figure. The major differences seen in this region are due to temperature effects -- sunlit slopes are warm (bright), whereas those in shadow are cold (dark), The temperature in this scene ranges from 50 oC (darkest) to 15 oC (brightest). The major differences between the different filters are due to the expected variation in the amount of energy emitted from the surface at different wavelengths. Minor spectral differences (infrared 'color') also exist between the different filters, but these differences are small in this region due to the uniform composition of the rocks and soils exposed at the surface. The THEMIS infrared camera provides an excellent regional view of Mars - this image covers an area 32 kilometers (20 miles) by approximately 200 kilometers (125 miles) at a resolution of 100 meters per picture element ('pixel'). This image provides a broad perspective of the landscape and geology of the Cydonia region, showing numerous knobs and hills that have been eroded into a remarkable array of different shapes. In this 'big picture' view the Cydonia region is seen to be covered with dozens of interesting knobs and mesas that are similar in many ways to the knob named the 'face' - so many in fact that it requires care to discover the 'face' among this jumble of knobs and hills. The 3-km

  7. The So-called 'Face on Mars' at Night

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    This pair of THEMIS infrared images shows the so-called 'face on Mars' landform viewed during both the day and night. The nighttime THEMIS IR image was acquired on Oct. 24, 2002; the daytime image was originally released on July 24, 2002. Both images are of THEMIS's 9th IR band (12.57 microns), and they have been geometrically projected for image registration. The 'face on Mars' is located in the northern plains of Mars near 40o N, 10o W (350 o E). This knob can be seen in the daytime image because of the temperature differences between the sunlit (warm and bright) and shadowed (cold and dark) slopes. The temperature in the daytime scene ranges from -50 oC (darkest) to -15 oC (brightest). At night many of the hills and knobs in this region are difficult to detect because the effects of heating and shadowing on the slopes are no longer present. The temperatures at night vary from approximately -90 oC (darkest) to -75 oC (warmest). The nighttime temperature differences are due primarily to differences in the abundance of rocky materials that retain their heat at night and stay warm. Fine grained dust and sand cools of more rapidly at night. The circular rims and eject of many of the craters in this region are warm at night, showing that rocks are still present on the steep walls inside the craters and in the ejecta material that was blasted out when the craters formed. Some craters have cold (dark) material on their floors in the night IR image, indicating that fine-grained material is accumulating within the craters. Many knobs and hills, including the 'face' have rocky (warm at night) material on their slopes and ridges.

    The THEMIS infrared camera provides an excellent regional view of Mars - these images cover an area 32 kilometers (20 miles) by approximately 50 kilometers (30 miles) at a resolution of 100 meters per picture element ('pixel'). The scenes are tilted differently because the Odyssey orbit is

  8. The So-called 'Face on Mars' at Night

    NASA Technical Reports Server (NTRS)

    2003-01-01

    [figure removed for brevity, see original site]

    This pair of THEMIS infrared images shows the so-called 'face on Mars' landform viewed during both the day and night. The nighttime THEMIS IR image was acquired on Oct. 24, 2002; the daytime image was originally released on July 24, 2002. Both images are of THEMIS's 9th IR band (12.57 microns), and they have been geometrically projected for image registration. The 'face on Mars' is located in the northern plains of Mars near 40o N, 10o W (350 o E). This knob can be seen in the daytime image because of the temperature differences between the sunlit (warm and bright) and shadowed (cold and dark) slopes. The temperature in the daytime scene ranges from -50 oC (darkest) to -15 oC (brightest). At night many of the hills and knobs in this region are difficult to detect because the effects of heating and shadowing on the slopes are no longer present. The temperatures at night vary from approximately -90 oC (darkest) to -75 oC (warmest). The nighttime temperature differences are due primarily to differences in the abundance of rocky materials that retain their heat at night and stay warm. Fine grained dust and sand cools of more rapidly at night. The circular rims and eject of many of the craters in this region are warm at night, showing that rocks are still present on the steep walls inside the craters and in the ejecta material that was blasted out when the craters formed. Some craters have cold (dark) material on their floors in the night IR image, indicating that fine-grained material is accumulating within the craters. Many knobs and hills, including the 'face' have rocky (warm at night) material on their slopes and ridges.

    The THEMIS infrared camera provides an excellent regional view of Mars - these images cover an area 32 kilometers (20 miles) by approximately 50 kilometers (30 miles) at a resolution of 100 meters per picture element ('pixel'). The scenes are tilted differently because the Odyssey orbit is

  9. BIOCHEMICAL STUDIES ON SO-CALLED SYPHILIS ANTIGEN.

    PubMed

    Noguchi, H; Bronfenbrenner, J

    1911-01-05

    of tissue is very variable. (c) Substances Soluble in Ether, Alcohol, and Aceton.-In this group are found varying amounts of fatty acids, both saturated and unsaturated, some neutral fats, cholesterin and many unidentified lipoidal bodies. This group causes either hemolysis or inhibition, of hemolysis. In other words, it is anticomplementary as well as hemolytic in the majority of preparations. At the same time, in some preparations it is, to a certain extent, antigenic. This great variation in the amounts of these substances in given extracts renders their presence in the antigen preparation undesirable. It is not denied, however, that, when added in adequate quantities, some of these substances may improve the activity of the antigenic lipoids. (d) Substances Insoluble in Aceton.-This group of substances consists of phosphatids. The best known among them is, of course, lecithin. Besides lecithin, however, there must be various other phosphatids present in this fraction. It will be noticed that the precipitate formed by mixing the ethereal solution with aceton contains a certain amount of lipoids insoluble in ether as well as in alcohol. Before the fractionation in aceton, all lipoids were soluble in ether or ethyl alcohol. Further analytical work on the nature of the phosphatids contained in this fraction is necessary. This fraction, in general, is more constant in amount in the various liver extracts. Biologically considered, it is the most important. It is usually non-hemolytic, frequently anticomplementary, but much more strongly antigenic than the other fractions. The antigenic strength varies with different preparations, being almost absent in the extracts derived from fatty livers. An aceton insoluble fraction may be strongly antigenic without any other auxiliary effects, or may be accompanied by an anticomplementary property. This fraction does not cause the so-called non-specific reaction with an active human serum. For these reasons it is recommended (as

  10. Prejudices in pharmacology and pharmacotherapy. The so-called anticholinergic effect of antidepressants.

    PubMed

    Bein, H J

    1977-09-01

    Imipramine and similarly acting compounds provoke a number of undesired reactions usually classified as so-called anticholinergic effects. Instances of dry mouth, disturbance of micturition and tachycardia are regularly quoted in the literature. It is contended that these effects are not necessarily due to inhibition of the vagal system, but preferentially attributable to increased activity of the sympathetic system, predominantly mediated by the beta- or the alpha-adrenergic receptors, depending on the organ affected. This hypothesis is not only theoretically interesting, but also of practical clinical significance with regard to possible remedies.

  11. Constructivism, the so-called semantic learning theories, and situated cognition versus the psychological learning theories.

    PubMed

    Aparicio, Juan José; Rodríguez Moneo, María

    2005-11-01

    In this paper, the perspective of situated cognition, which gave rise both to the pragmatic theories and the so-called semantic theories of learning and has probably become the most representative standpoint of constructivism, is examined. We consider the claim of situated cognition to provide alternative explanations of the learning phenomenon to those of psychology and, especially, to those of the symbolic perspective, currently predominant in cognitive psychology. The level of analysis of situated cognition (i.e., global interactive systems) is considered an inappropriate approach to the problem of learning. From our analysis, it is concluded that the pragmatic theories and the so-called semantic theories of learning which originated in situated cognition can hardly be considered alternatives to the psychological learning theories, and they are unlikely to add anything of interest to the learning theory or to contribute to the improvement of our knowledge about the learning phenomenon.

  12. ["Lump them all together?" Critical remarks on the psychoanalysis of so-called "destructive cults"

    PubMed

    Kraus, Daniel

    1999-01-01

    Contributions to the psychoanalysis of so-called "destructive cults" are reviewed and criticized for several overgeneralizations. In order to gain a full understanding of religious feelings and commitments it is necessary to distinguish between different qualities of regression in a religious context. Religious groups differ in their "psychological offers" and therefore tendencywise in their members' personality structures, too. With regard to destructive developments of religious groups we must consider that collective projective identification with these groups can encourage such trends. Empirical results concerning commitments to so-called "destructive cults" are highly dependent on paradigms and research methods. In their entirety they rather contradict the assumption that the majority of these groups' members has severe personality disorders. As a consequence of the current status of research and discussion, religiosity should be respected as a complex domain of human experience that, despite the possibility of mixing with psychopathological tendencies, should not necessarily lose its creative potential.

  13. Human Nuclear Genome Transfer (So-Called Mitochondrial Replacement): Clearing the Underbrush.

    PubMed

    Baylis, Françoise

    2017-01-01

    In this article, I argue that there is no compelling therapeutic 'need' for human nuclear genome transfer (so-called mitochondrial replacement) to prevent mitochondrial diseases caused by mtDNA mutations. At most there is a strong interest in (i.e. 'want' for) this technology on the part of some women and couples at risk of having children with mitochondrial disease, and perhaps also a 'want' on the part of some researchers who see the technology as a useful precedent - one that provides them with 'a quiet way station' in which to refine the micromanipulations techniques essential for other human germline interventions and human cloning. In advance of this argument, I review basic information about mitochondrial disease and novel genetic strategies to prevent the transmission of mutated mitochondria. Next, I address common features of contemporary debates and discussions about so-called mitochondrial replacement. First, I contest the cliché that science-and-(bio)technology is fast outpacing ethics. Second, I dispute the accuracy of the term 'mitochondrial replacement'. Third, I provide a sustained critique of the purported 'need' for genetically-related children. In closing, I call into question the mainly liberal defense of human nuclear genome transfer. I suggest an alternative frame of reference that pays particular attention to issues of social justice. I conclude that our limited resources (time, talent, human eggs, and money) should be carefully expended in pursuit of the common good, which does not include pandering to acquired desires (i.e., wants).

  14. Reclassification and subtyping of so-called malignant fibrous histiocytoma of bone: comparison with cytogenetic features

    PubMed Central

    2011-01-01

    Background The diagnostic entity malignant fibrous histiocytoma (MFH) of bone is, like its soft tissue counterpart, likely to be a misnomer, encompassing a variety of poorly differentiated sarcomas. When reviewing a series of 57 so-called MFH of bone within the framework of the EuroBoNeT consortium according to up-to-date criteria and ancillary immunohistochemistry, a fourth of all tumors were reclassified and subtyped. Methods In the present study, the cytogenetic data on 11 of these tumors (three myoepithelioma-like sarcomas, two leiomyosarcomas, one undifferentiated pleomorphic sarcoma with incomplete myogenic differentiation, two undifferentiated pleomorphic sarcomas, one osteosarcoma, one spindle cell sarcoma, and one unclassifiable biphasic sarcoma) are presented. Results All tumors were high-grade lesions and showed very complex karyotypes. Neither the overall pattern (ploidy level, degree of complexity) nor specific cytogenetic features distinguished any of the subtypes. The subgroup of myoepithelioma-like sarcomas was further investigated with regard to the status of the EWSR1 and FUS loci; however, no rearrangement was found. Nor was any particular aberration that could differentiate any of the subtypes from osteosarcomas detected. Conclusions chromosome banding analysis is unlikely to reveal potential genotype-phenotype correlations between morphologic subtypes among so-called MFH of bone. PMID:22588017

  15. New interpretation of the so-called Nubian strata in northeast Africa

    SciTech Connect

    Klitzsch, E.H.; Squyres, C.H.

    1988-08-01

    Stratigraphical interpretation of the so-called Nubian Sandstone of Egypt and northern Sudan have led to new ideas on the structural and paleogeographical development of northeast Africa. The strata formerly comprised under the term Nubian Sandstone include sediments from Cambrian to Paleocene age. Based on field work and paleontological investigations during the last 10 years, these strata can be subdivided into three major cycles, each characterizing a certain structural situation of northeast Africa. The first or Paleozoic cycle comprises strata of Cambrian to Early Carboniferous age. These strata were deposited during a period of generally northern dip of northeast Africa; continental sediments transported northward interfinger with marine strata resulting from southward transgressions. Sediments of the second cycle were deposited during and after Gondwana and northern continents collided, which caused updoming of large areas of Egypt and bordering areas to the west and east. As a result, most of Egypt became subject to erosion; transgressions remained near the present northern edge of the continent, and purely continental deposition took place in northern Sudan and bordering areas in Chad and Libya. The resulting strata are similar to the Karroo of East Africa. Strata of the third cycle were deposited after Pangea began to disintegrate. Northeast Africa now had a generally northern dip again, and consequently deposition was controlled - as during the first cycle - by northward drainage and southward transgressions. This last cycle began during Late Jurassic time.

  16. Magnetic Nanoparticles for Tumor Imaging and Therapy: A So-called Theranostic System

    PubMed Central

    He, Huining; David, Allan; Chertok, Beata; Cole, Adam; Lee, Kyuri; Zhang, Jian; Wang, Jianxin; Huang, Yongzhuo; Yang, Victor C.

    2014-01-01

    In this review, we discussed the establishment of a so-called “theranostic“ system by instituting the basic principles including the use of: [1] magnetic iron oxide nanoparticles (MION)-based drug carrier; [2] intra-arterial (I.A.) magnetic targeting; [3] macromolecular drugs with unmatched therapeutic potency and a repetitive reaction mechanism; [4] cell-penetrating peptide-mediated cellular drug uptake; and [5] heparin/protamine-regulated prodrug protection and tumor-specific drug re-activation into one single drug delivery system to overcome all possible obstacles, thereby achieving a potentially non-invasive, magnetic resonance imaging-guided, clinically enabled yet minimally toxic brain tumor drug therapy. By applying a topography-optimized I.A. magnetic targeting to dodge rapid organ clearance of the carrier during its first passage into the circulation, tumor capture of MION was enriched by >350 folds over that by conventional passive enhanced permeability and retention targeting. By adopting the prodrug strategy, we observed by far the first experimental success in a rat model of delivering micro-gram quantity of the large β-galactosidase model protein selectively into a brain tumor but not to the ipsi- or contra-lateral normal brain regions. With the therapeutic regimens of most toxin/siRNA drugs to fully (>99.9%) eradicate a tumor being in the nano-molar range, the prospects of reaching this threshold become practically accomplishable. PMID:23344909

  17. Nursing so-called monsters: on the importance of abjection and fear in forensic psychiatric nursing.

    PubMed

    Jacob, Jean Daniel; Gagnon, Marilou; Holmes, Dave

    2009-01-01

    Forensic psychiatric nurses work with individuals who may evoke feelings of empathy as well as feelings of disgust, repulsion, and fear. The main objective of this theoretical paper is to engage the readers in a theoretical reflection regarding the concepts of abjection and fear since they both apply to the experiences of caring for mentally ill individuals in forensic psychiatric settings. Our contention is with the potential impact of feelings such as disgust, repulsion, and fear on the therapeutic relationship and, more particularly, with the boundaries imposed on this relationship when these feelings are unrecognized by nurses. Acknowledging that patients may evoke feelings of disgust, repulsion, and fear is essential if nurses wish to understand the implications of these emotions in the therapeutic process. In forensic psychiatric settings, caring for so-called "monsters" in the face of abjection and fear is not an easy task to achieve given the lack of theoretical understanding regarding both concepts. Given the actual state of knowledge in forensic nursing, we argue that theoretical (conceptual) analyses, as well as ethical and political discussions, are paramount if we wish to understand the specificities of this complex field of nursing practice.

  18. Metabolic engineering for the microbial production of marine bioactive compounds.

    PubMed

    Mao, Xiangzhao; Liu, Zhen; Sun, Jianan; Lee, Sang Yup

    2017-03-06

    Many marine bioactive compounds have medicinal and nutritional values. These bioactive compounds have been prepared using solvent-based extraction from marine bio-resources or chemical synthesis, which are costly, inefficient with low yields, and environmentally unfriendly. Recent advances in metabolic engineering allowed to some extent more efficient production of these compounds, showing promises to meet the increasing demand of marine natural bioactive compounds. In this paper, we review the strategies and statuses of metabolic engineering applied to microbial production of marine natural bioactive compounds including terpenoids and their derivatives, omega-3 polyunsaturated fatty acids, and marine natural drugs, and provide perspectives.

  19. MICROBIAL VOLATILE ORGANIC COMPOUND EMISSION RATES AND EXPOSURE MODEL

    EPA Science Inventory

    This paper presents the results from a study that examined microbial volatile organic compound (MVOC) emissions from six fungi and one bacterial species (Streptomyces spp.) commonly found in indoor environments. Data are presented on peak emission rates from inoculated agar plate...

  20. Microbial Fuel Cell Transformation of Recalcitrant Organic Compounds in Support of Biosensor Research

    DTIC Science & Technology

    2014-03-27

    Microbial Fuel Cell Transformation of Recalcitrant Organic Compounds in Support of Biosensor ...in the United States. AFIT-ENV-14-M-62 Microbial Fuel Cell Transformation of Recalcitrant Organic Compounds in Support of Biosensor Research...DISTRIBUTION UNLIMITED AFIT-ENV-14-M-62 Microbial Fuel Cell Transformation of Recalcitrant Organic Compounds in Support of Biosensor Research Marc

  1. On the So-Called Variational Consistency of Plate Models, I. Indefinite Plates: Evaluation of Dispersive Behaviour

    NASA Astrophysics Data System (ADS)

    Muller, P.; Touratier, M.

    1995-12-01

    Four groups of refined shear-deformation plate theories are examined, including the so-called variationally inconsistent theories of Schmidt-Levinson and Touratier—whose "inconsistence" is in fact weak. After a unified presentation of these two-dimensional theories, all are deduced from the three-dimensional theory of elasticity through a suitable variation procedure which disconnects the choice of the so-called virtual motions from the choice of an approximation for the small displacement field. This procedure makes obvious in a natural way the importance of the stress boundary conditions on the faces of the pate for any two-dimensional theory. As a test comparison, a wave dispersion evaluation of these theories is performed for the propagation of flexural waves in an indefinite plate. A detailed comparison leads to the conclusion that the inconsistent theories may offer some advantages in the domain of short waves.

  2. Multiple microbial activities for volatile organic compounds reduction by biofiltration.

    PubMed

    Civilini, Marcello

    2006-07-01

    In the northeast of Italy, high volatile organic carbon (VOC) emissions originate from small-medium companies producing furniture. In these conditions it is difficult to propose a single, efficient, and economic system to reduce pollution. Among the various choices, the biofiltration method could be a good solution, because microbial populations possess multiple VOC degradation potentials used to oxidize these compounds to CO2. Starting from the air emissions of a typical industrial wood-painting plant, a series of experiments studied in vitro microbial degradation of each individual VOC. Isolated strains were then added to a laboratory-scale biofiltration apparatus filled with an organic matrix, and the different VOC behavior demonstrated the potential of single and/or synergic microbial removal actions. When a single substrate was fed, the removal efficiency of a Pseudomonas aeruginosa inoculated reactor was 1.1, 1.17, and 0.33 g m(-3) hr(-1), respectively, for xylene, toluene, and ethoxy propyl acetate. A VOC mixture composed of butyl acetate, ethyl acetate, diacetin alcohol, ethoxy propanol acetate, methyl ethyl ketone, methyl isobutyl ketone, toluene, and xylene was then fed into a 2-m(3) reactor treating 100 m3 hr(-1) of contaminated air. The reactor was filled with the same mixture of organic matrix, enriched with all of the isolated strains together. During reactor study, different VOC loading rates were used, and the behavior was evaluated continuously. After a short acclimation period, the removal efficiency was > 65% at VOC load of 150-200 g m(-3) hr(-1). Quantification of removal efficiencies and VOC speciation confirmed the relationship among removal efficiencies, compound biodegradability, and the dynamic transport of each mixture component within the organic matrix. Samples of the fixed bed were withdrawn at different intervals and the heterogeneous microbial community evaluated for both total and differential compound counts.

  3. Immense essence of excellence: marine microbial bioactive compounds.

    PubMed

    Bhatnagar, Ira; Kim, Se-Kwon

    2010-10-15

    Oceans have borne most of the biological activities on our planet. A number of biologically active compounds with varying degrees of action, such as anti-tumor, anti-cancer, anti-microtubule, anti-proliferative, cytotoxic, photo protective, as well as antibiotic and antifouling properties, have been isolated to date from marine sources. The marine environment also represents a largely unexplored source for isolation of new microbes (bacteria, fungi, actinomycetes, microalgae-cyanobacteria and diatoms) that are potent producers of bioactive secondary metabolites. Extensive research has been done to unveil the bioactive potential of marine microbes (free living and symbiotic) and the results are amazingly diverse and productive. Some of these bioactive secondary metabolites of microbial origin with strong antibacterial and antifungal activities are being intensely used as antibiotics and may be effective against infectious diseases such as HIV, conditions of multiple bacterial infections (penicillin, cephalosporines, streptomycin, and vancomycin) or neuropsychiatric sequelae. Research is also being conducted on the general aspects of biophysical and biochemical properties, chemical structures and biotechnological applications of the bioactive substances derived from marine microorganisms, and their potential use as cosmeceuticals and nutraceuticals. This review is an attempt to consolidate the latest studies and critical research in this field, and to showcase the immense competence of marine microbial flora as bioactive metabolite producers. In addition, the present review addresses some effective and novel approaches of procuring marine microbial compounds utilizing the latest screening strategies of drug discovery.

  4. Microbial cycling of volatile organic sulfur compounds in anoxic environments.

    PubMed

    Lomans, B P; Pol, A; Op den Camp, H J M

    2002-01-01

    Microbial cycling of volatile organic sulfur compounds (VOSC) is investigated due to the impact these compounds are thought to have on environmental processes like global temperature control, acid precipitation and the global sulfur cycle. Moreover, in several kinds of industries like composting plants and the paper industry VOSC are released causing odor problems. Waste streams containing these compounds must be treated in order to avoid the release of these compounds to the atmosphere. This paper describes the general mechanisms for the production and degradation of methanethiol (MT) and dimethyl sulfide (DMS), two ubiquitous VOSC in anaerobic environments. Slurry incubations indicated that methylation of sulfide and MT resulting in MT and DMS, respectively, is one of the major mechanisms for VOSC in sulfide-rich anaerobic environments. An anaerobic bacterium that is responsible for the formation of MT and DMS through the anaerobic methylation of H2S and MT was isolated from a freshwater pond after enrichment with syringate as a methyl group donating compound and sole carbon source. In spite of the continuous formation of MT and DMS, steady state concentrations are generally very low. This is due to the microbial degradation of these compounds. Experiments with sulfate-rich and sulfate-amended sediment slurries demonstrated that besides methanogens, sulfate-reducing bacteria can also degrade MT and DMS, provided that sulfate is available. A methanogen was isolated that is able to grow on DMS as the sole carbon source. A large survey of sediments slurries of various origin demonstrated that both isolates are commonly occurring inhabitants of anaerobic environments.

  5. Microbial degradation of non-polar nitroaromatic compounds

    SciTech Connect

    Peres, C.; Naveau, H.; Agathos, S.N.

    1995-12-01

    Using a semi-continuous enrichment technique, a microbial consortium able to degrade aerobically a spectrum of nitroaromatic compounds (NACs) has been obtained. At least four NACs are degraded efficiently in the presence of an external C-source: 2-nitrotoluene (2-NT), 2,4-dinitrotoluene (2,4-DNT), 2,4,6-trinitrotoluene (TNT) and 1,3-dini-trobenzene (1,3-DNB). The microorganisms degrade the NACs by a reductive pathway, as shown by the presence of ammonium and aminoaromatic compounds, such as 4-amino-2-NT and 2-amino-4-NT (reduction products of 2,4-DNT) and 2-aminotoluene (product of 2-NT). The latter compounds appear transiently in the medium and are further degraded. The degradation kinetics are highly dependent on C-source and on pH. No abiotic transformation of 1,3-DNB or 2-4-DNT was detected, whereas about 10% of the TNT disappearance observed in the presence of the microbial consortium could be attributed to an abiotic route. The latter is strongly influenced by pH, higher values of which allow a larger extent of abiotic TNT transformation.

  6. Control of malodorous hydrogen sulfide compounds using microbial fuel cell.

    PubMed

    Eaktasang, Numfon; Min, Hyeong-Sik; Kang, Christina; Kim, Han S

    2013-10-01

    In this study, a microbial fuel cell (MFC) was used to control malodorous hydrogen sulfide compounds generated from domestic wastewaters. The electricity production demonstrated a distinct pattern of a two-step increase during 170 h of system run: the first maximum current density was 118.6 ± 7.2 mA m⁻² followed by a rebound of current density increase, reaching the second maximum of 176.8 ± 9.4 mA m⁻². The behaviors of the redox potential and the sulfate level in the anode compartment indicated that the microbial production of hydrogen sulfide compounds was suppressed in the first stage, and the hydrogen sulfide compounds generated from the system were removed effectively as a result of their electrochemical oxidation, which contributed to the additional electricity production in the second stage. This was also directly supported by sulfur deposits formed on the anode surface, which was confirmed by analyses on those solids using a scanning electron microscope equipped with energy dispersive X-ray spectroscopy as well as an elemental analyzer. To this end, the overall reduction efficiencies for HS⁻ and H₂S(g) were as high as 67.5 and 96.4 %, respectively. The correlations among current density, redox potential, and sulfate level supported the idea that the electricity signal generated in the MFC can be utilized as a potential indicator of malodor control for the domestic wastewater system.

  7. Competitive adsorption of organic compounds by microbial biomass

    SciTech Connect

    Selvakumar, A.; Hsieh, H.N. )

    1988-01-01

    This study investigated the effect of competitive adsorption of liquid organic compounds on inactive microbial biomass in bisolute solution systems. Phenol-nitrophenol, phenol-chlorophenol, nitrophenol-chlorophenol, and chlorobenzene-ethylbenzene systems were selected for the analysis. The experimental results suggest that although the amount of each solute adsorbed on the biomass can be reduced significantly by the presence of a second solute, the combined adsorptive capacity was greater than that for either of the individual substances from its pure solution. The octanol/water partition coefficient(K{sub ow}) indicates the relative extent of adsorption better than the aqueous solubility(S).

  8. Influence of microbial biomass on the biodegradability of organic compounds

    SciTech Connect

    Kool, H.J.

    1984-01-01

    The influence of different types of inocula as well as the amount of inoculum (microbial biomass) on the biodegradation pattern of acetate, 4-nitrophenol, and the three methoxyaniline isomers was investigated in the Modified OECD test and a NPR guideline. Using sediment of the river Rhine as inoculum 4-nitrophenol could not be degraded, while an inoculum from garden soil gave only 60% degradation in the OECD test. Effluent of an activated sludge plant however was able to degrade 4-nitrophenol at a concentration of 19 mg/l in the OECD test completely. Testing the methoxyanilines for biodegradability it was found that at a low inoculum level (OECD protocol) no degradation of the three compounds occurred. Using activated sludge as inoculum 3- and 4-methoxyaniline could be degraded for 60% respectively completely while 2-methoxyaniline was still refractory to degradation. Measuring the microbial biomass by means of ATP during biodegradation strongly suggested that the microbial flora which rapidly metabolize acetate is quite another microflora than the microflora responsible for the degradation of 4-nitrophenol.

  9. Microbial Turnover of Fixed Nitrogen Compounds in Oceanic Crustal Fluids

    NASA Astrophysics Data System (ADS)

    Kraft, B.; Wankel, S. D.; Glazer, B. T.; Huber, J. A.; Girguis, P. R.

    2014-12-01

    Oceanic crust is the largest aquifer on Earth, with a massive volume of seawater advecting through the basaltic crust. The microbiome of this deep marine subsurface biosphere has been estimated to be substantial, and consequently their metabolic activity may have major influences on global biogeochemical cycles. While earlier and recent studies provide insight into the microbial community composition of oceanic crustal fluids, information on the microbial ecophysiology is broadly missing. Therefore, to investigate the microbial transformation of fixed nitrogen compounds in crustal aquifer fluids, fluids were sampled from different horizons of two neighbouring CORK (Circulation Obviation Retrofit Kit) observatories at the North Pond sediment pond. This site is located on the western flank of the Mid Atlantic Ridge and is characterized by relatively young oceanic crust and cold fluids. The crustal fluids contain oxygen and nitrate, which potentially both may serve as electron acceptor for respiration. In a multidisciplinary approach we combined stable isotope incubations, determination of the natural isotopic compositions and plan to analyse relevant functional genes from a metagenomic dataset to investigate the nitrogen cycling at North Pond. The turnover of fixed nitrogen in oceanic crustal fluids may have important implications for the understanding of the global nitrogen cycle.

  10. Effect of two sweating simulation methods on clothing evaporative resistance in a so-called isothermal condition.

    PubMed

    Lu, Yehu; Wang, Faming; Peng, Hui

    2016-07-01

    The effect of sweating simulation methods on clothing evaporative resistance was investigated in a so-called isothermal condition (T manikin  = T a  = T r ). Two sweating simulation methods, namely, the pre-wetted fabric "skin" (PW) and the water supplied sweating (WS), were applied to determine clothing evaporative resistance on a "Newton" thermal manikin. Results indicated that the clothing evaporative resistance determined by the WS method was significantly lower than that measured by the PW method. In addition, the evaporative resistances measured by the two methods were correlated and exhibited a linear relationship. Validation experiments demonstrated that the empirical regression equation showed highly acceptable estimations. The study contributes to improving the accuracy of measurements of clothing evaporative resistance by means of a sweating manikin.

  11. Effect of two sweating simulation methods on clothing evaporative resistance in a so-called isothermal condition

    NASA Astrophysics Data System (ADS)

    Lu, Yehu; Wang, Faming; Peng, Hui

    2016-07-01

    The effect of sweating simulation methods on clothing evaporative resistance was investigated in a so-called isothermal condition ( T manikin = T a = T r ). Two sweating simulation methods, namely, the pre-wetted fabric "skin" (PW) and the water supplied sweating (WS), were applied to determine clothing evaporative resistance on a "Newton" thermal manikin. Results indicated that the clothing evaporative resistance determined by the WS method was significantly lower than that measured by the PW method. In addition, the evaporative resistances measured by the two methods were correlated and exhibited a linear relationship. Validation experiments demonstrated that the empirical regression equation showed highly acceptable estimations. The study contributes to improving the accuracy of measurements of clothing evaporative resistance by means of a sweating manikin.

  12. [Scanning electron microscopic study of so-called carvable composite filling materials after over one-year functional period].

    PubMed

    Triadan, H

    1979-03-01

    28 class-5 and 16 class-1 fillings were made from the composite material "Epoxydent" on a macaca speciosa monkey and examined with the electron microscope after a 15 months functional period. Statistically significant differences in the size of the marginal space were found to be larger than in comparable composites Adaptic, Concise, Compo-Cap and Cosmic. The spaces were frequently not located on the filling margin but inside, within the filling material. This is attributed to the "carving" technique during the gel phase of setting. The surface shows abrasions and porosities with loss of particles, sometimes fractures and discolored margins with secondary caries. It is not recommended to replace metal fillings by so-called carvable composits.

  13. A so-called carcinosarcoma of the gallbladder in a patient with multiple anomalies--a case report.

    PubMed

    Eriguchi, N; Aoyagi, S; Hara, M; Hashino, K; Imamura, M; Sato, S; Imamura, I; Kutami, R; Jimi, A

    1999-01-01

    The patient was a 65-year-old woman with a chief complaint of right upper quadrant pain. Under the diagnosis of gallbladder tumor, preduodenal portal vein and absence of the pancreatic tail, cholecystectomy was performed. Intraoperative findings resulted in a diagnosis of gallbladder tumor, absence of the pancreatic tail, presence of preduodenal portal vein, and malrotation of the intestine. Histological examination of the resected specimens showed a so-called carcinosarcoma. Carcinosarcoma of the gallbladder is a rare tumor of the hepatobiliary region. The present case differs from previously reported cases in its presentation with multiple anomalies including the presence of preduodenal portal vein. Many cases of preduodenal portal vein in an association with duodenal stenosis in children have been reported, but reports of cases of preduodenal portal vein in adult patients are rarely seen in the literature.

  14. Adaptation of Aquatic Microbial Communities to Quaternary Ammonium Compounds

    PubMed Central

    Ventullo, Roy M.; Larson, Robert J.

    1986-01-01

    The effects of long-chain (C12 to C18) quaternary ammonium compounds (QACs) on the density, heterotrophic activity, and biodegradation capabilities of heterotrophic bacteria were examined in situ in a lake ecosystem. Monoalkyl and dialkyl substituted QACs were tested over a range of concentrations (0.001 to 10 mg/liter) in both acute (3 h) and chronic (21 day) exposures. In general, none of the QACs tested had significant adverse effects on bacterial densities in either acute or chronic studies. However, significant decreases in bacterial heterotrophic activity were noted in acute studies at QAC concentrations from 0.1 to 10 mg/liter. Chronic exposure of lake microbial communities to a specific monoalkyl QAC resulted in an adaptive response and recovery of heterotrophic activity. No-observable-effect level in the adapted populations was >10 mg/liter. Chronic exposure also resulted in significant increases in the number and activity of bacteria capable of biodegrading the material. The increase in biodegradation capability was observed at low (microgram per liter) concentrations which are approximately the same as realistic environmental levels. In general, our studies indicated that exposure of lake microbial communities to QACs results in the development of adapted communities which are less sensitive to potential toxic effects and more active in the biodegradation of these materials. PMID:16346991

  15. The antiperinuclear factor and the so-called antikeratin antibodies are the same rheumatoid arthritis-specific autoantibodies.

    PubMed Central

    Sebbag, M; Simon, M; Vincent, C; Masson-Bessière, C; Girbal, E; Durieux, J J; Serre, G

    1995-01-01

    The so-called antikeratin antibodies (AKA) and the antiperinuclear factor (APF) are the most specific serological markers of RA. Using indirect immunofluorescence, AKA label the stratum corneum of various cornified epithelia and APF the keratohyalin granules of human buccal mucosa epithelium. We recently demonstrated that AKA recognize human epidermal filaggrin. Here, we report the identification of the major APF antigen as a diffuse protein band of 200-400 kD. This protein is seen to be closely related to human epidermal (pro) filaggrin since it was recognized by four antifilaggrin mAbs specific for different epitopes, and since the APF titers of RA sera were found to be correlated to their AKA titers and to their immunoblotting reactivities to filaggrin. Immunoabsorption of RA sera on purified epidermal filaggrin abolished their reactivities to the granules of buccal epithelial cells and to the 200-400-kD antigen. Moreover, antifilaggrin autoantibodies, i.e., AKA, affinity purified from RA sera, were shown to immunodetect the 200-400-kD antigen and to stain these granules. These results indicate that AKA and APF are largely the same autoantibodies. They recognize human epidermal filaggrin and (pro) filaggrin-related proteins of buccal epithelial cells. Identification of the epitopes recognized by these autoantibodies, which we propose to name antifilaggrin autoantibodies, will certainly open new paths of research into the pathophysiology of RA. Images PMID:7539459

  16. The fauna of the so-called Dakota formation of northern central Colorado and its equivalent in southeastern Wyoming

    USGS Publications Warehouse

    Reeside, John B.

    1923-01-01

    This paper describes a small fauna from beds in northern central Colorado that have long been designated the Dakota formation, often with doubt that all the beds so named were really equivalent to the typical Dakota sandstone of eastern Nebraska. The upper part of the equivalent beds in southeastern Wyoming was referred by some writers to the Benton Shale and the lower part of the Cloverly formation. This so-called Dakota formation of northern central Colorado and its equivalent in southeastern Wyoming consist of cherty conglomerate, brown quartzose sandstone, and dark shale. The conglomerate is usually at the base of the series and at many localities is overlain by a single shale unit and that in turn by a sandstone. At other localities, however, there are several alternations of sandstone and shale above the basal conglomeratic layer. The fossil described in this paper, except one specimen, were obtained from the shales of the middle part of the formation. The single specimen, an ammonite, came from the uppermost sandstone.

  17. The so-called "Spanish model" - Tobacco industry strategies and its impact in Europe and Latin America

    PubMed Central

    2011-01-01

    Background To demonstrate the tobacco industry rationale behind the "Spanish model" on non-smokers' protection in hospitality venues and the impact it had on some European and Latin American countries between 2006 and 2011. Methods Tobacco industry documents research triangulated against news and media reports. Results As an alternative to the successful implementation of 100% smoke-free policies, several European and Latin American countries introduced partial smoking bans based on the so-called "Spanish model", a legal framework widely advocated by parts of the hospitality industry with striking similarities to "accommodation programmes" promoted by the tobacco industry in the late 1990s. These developments started with the implementation of the Spanish tobacco control law (Ley 28/2005) in 2006 and have increased since then. Conclusion The Spanish experience demonstrates that partial smoking bans often resemble tobacco industry strategies and are used to spread a failed approach on international level. Researchers, advocates and policy makers should be aware of this ineffective policy. PMID:22151884

  18. Origin of the color of Cv. rhapsody in blue rose and some other so-called "blue" roses.

    PubMed

    Gonnet, Jean-François

    2003-08-13

    Flowers of the rose cultivar Rhapsody in Blue display unusual colors, changing as they age, from a vivid red-purple to a lighter and duller purple, which are based on tonalities corresponding to hue angles between 340 and 320 degrees in the CIELAB scale. Unexpectedly, the chemical basis of these colors is among the simplest, featuring cyanin (cyanidin 3,5-di-O-glucoside), the most frequent anthocyanin in flowers, as the sole pigment and quercetin kaempferol glycosides as copigments at a relatively low copigment/pigment ratio (about 3/1), which usually produces magenta or red shades in roses. This color shift to bluer shades is coupled with the progressive accumulation of cyanin into vacuolar anthocyanic inclusions (AVIs), the occurrence of which increases as the petals grow older. In addition to the normal lambda(max) of cyanin at approximately 545 nm, the transmission spectra of live petals and of epidermal cells exhibit a second lambda(max) in the 620-625 nm range, the relative importance increasing with the presence of AVIs. In petals of fully opened flowers, the only pigmented structures in the vacuoles of epidermal cells are AVIs; their intense and massive absorption in the 520-640 nm area produces a much darker and bluer color than measured for the vacuolar solution present at the very first opening stage. Cyanin is probably "trapped" into AVIs at higher concentrations than would be possible in a vacuolar solution and in quinonoidal form, appearing purple-blue because of additional absorption in the 580-630 nm area. Quite similar pigmentation features were found in very ancient rose cultivars (cv. L'Evêque or Bleu Magenta), also displaying this type of so-called "blue" color.

  19. Usefulness of K-Point Injection for the Nonspecific Neck Pain in So-Called K-Point Syndrome

    PubMed Central

    Moon, Jeong Jae; Ahn, Hyo Sae; Lee, Sung Jun; Lee, Dong Yeol

    2016-01-01

    Background Shoichi Kokubun introduced his successful experience with local anesthetic injection at the occipital insertion of the sternocleidomastoid muscle in K-point syndrome. The purpose of this study was to evaluate the short-term and long-term effectiveness of K-point injection and investigate factors affecting treatment results. Methods K-point injection was performed in 58 patients with K-point syndrome at Yeungnam University Medical Center. The syndrome was associated with cervical whiplash injury in 10 patients and was of nonspecific origin in the rest. One milliliter of 2% lidocaine mixed with 1 milliliter of dexamethasone was injected in 50 patients and 2 milliliters of 1% lidocaine alone in the rest. Initially, the severity of local tenderness at the K-point and other tender points was examined and the degree of immediate pain relief effect was assessed within 1 hour after injection. Early effect within 1 month after the injection and current effect were evaluated in 27 patients using a modified Kim's questionnaire with regard to the duration of improvement, degree of improvement in pain and daily living activities, and satisfaction. Results Of the total 58 patients, 44 (75.8%) apparently had immediate pain relief after K-point injection. The only factor associated with successful immediate pain relief was the whiplash injury associated with traffic accident (TA). The early pain control effect was associated with the immediate effect. The current effect was associated with the early effect alone. Satisfaction with the K-point injection was related to early successful pain relief. Conclusions K-point injection would be useful for early pain relief in nonspecific neck pain syndrome so called K-point syndrome, but not for current pain relief. Especially, it was very effective for early pain control in the whiplash injury associated with TA. PMID:27904721

  20. Reappraisal of the intracranial pressure and cerebrospinal fluid dynamics in patients with the so-called "normal pressure hydrocephalus" syndrome.

    PubMed

    Sahuquillo, J; Rubio, E; Codina, A; Molins, A; Guitart, J M; Poca, M A; Chasampi, A

    1991-01-01

    Fifty-four shunt-responsive patients were selected from a prospective protocol directed to study patients with suspected normal pressure hydrocephalus (NPH). Patients with gait disturbances, dementia, non-responsive L-Dopa Parkinsonism, urinary or faecal incontinence and an Evans ratio greater or equal to 0.30 on the CT scan were included in the study. As a part of their work-up all patients underwent intracranial pressure monitoring and hydrodynamic studies using Marmarou's bolus test. According to mean intracranial pressure (ICP) and the percentage of high amplitude B-waves, patients were subdivided in the following categories: 1) Active hydrocephalus (mean ICP above 15 mmHg), which is in fact no tone normal pressure hydrocephalus; 2) Compensated unstable hydrocephalus, when mean ICP was below 15 mmHg and B-waves were present in more than 25% of the total recording time and 3) Compensated stable hydrocephalus when ICP was lower or equal to 15 mmHg and beta waves were present in less than 25% of the total recording time. The majority of the patients in this study (70%) presented continuous high or intermittently raised ICP (active or unstable compensated hydrocephalus group). Mean resistance to outflow of CSF (Rout) was 38.8 mm Hg/ml/min in active hydrocephalus and 23.5 mm Hg/ml/min in the compensated group (Students t-test, p less than 0.05). Higher resistance to outflow was found in patients with obliterated cortical sulci and obliterated Sylvian cisterns in the CT scan. No statistically significant correlation was found when plotting the percentage of beta waves against pressure volume index (PVI), compliance or Rout. An exponential correlation was found when plotting beta waves against the sum of conductance to outflow and compliance calculated by PVI method (r = 0.79). Patients with the so-called normal pressure hydrocephalus syndrome have different ICP and CSF dynamic profiles. Additional studies taking into consideration these differences are necessary

  1. A conceptual framework for an ecosystem services-based assessment of the so-called "emergency stabilization" measures following wildfire

    NASA Astrophysics Data System (ADS)

    Valente, Sandra; Prats, Sergio; Ribeiro, Cristina; Verheijen, Frank; Fleskens, Luuk; Keizer, Jacob

    2015-04-01

    Wildfires have become a major environmental concern in many Southern European countries over the past few decades. This includes Portugal, where, on average, some 100 000 ha of rural lands are affected by wildfire every year. While policies, laws, plans and public expenditure in Portugal continue to be largely directed towards fire combat and, arguably, to a lesser extent fire prevention, there has only recently been increasing attention for post-fire land management. For example following frequent and several large wildfires during the summer of 2010, so-called emergency stabilization measures were implemented in 16 different burnt areas in northern and central Portugal, using funds of the EU Rural Development Plan in Portugal (PRODER). The measures that were implemented included mulching (i.e. application of a protective layer of organic material), seeding and the construction of log barriers. However, the effectiveness of the implemented measures has not been monitored or otherwise assessed in a systematic manner. In fact, until very recently none of the post-fire emergency stabilization measures contemplated under PRODER seem to have been studied in an exhaustive manner in Portugal, whether under laboratory or field conditions. Prats et al. (2012, 2013, 2014) tested two of these measures by field trials, i.e. hydro-mulching and forest residue mulching. The authors found both measures to be highly effective in terms of reducing overland flow and especially erosion. It remains a challenge, however, to assess the effectiveness of these and other measures in a broader context, not only beyond overland flow and sediment losses but also beyond the spatio-temporal scale that are typical for such field trials (plots and the first two years after fire). This challenge will be addressed in the Portuguese case study of the RECARE project. Nonetheless, the present study wants to be a first attempt at an ecosystem services-based assessment of mulching as a post

  2. Characterization by volatile compounds of microbial deep spoilage in Iberian dry-cured ham.

    PubMed

    Martín, Alberto; Benito, María J; Aranda, Emilio; Ruiz-Moyano, Santiago; Córdoba, Juan J; Córdoba, María G

    2010-08-01

    In the present study, volatile compounds of spoiled dry-cured Iberian ham with deep spoilage or "bone taint" were analyzed and correlated with level of spoilage and the microorganisms detected. Volatile compounds extracted by a solid phase micro-extraction technique were assayed by gas chromatography/mass spectrometry. The spoiled hams were evaluated sensorially, and the correlations among volatile compounds, spoilage level, and microbial counts were studied. The spoiled hams had higher concentrations of hydrocarbons, alcohols, acids, esters, pyrazines, sulfur compounds, and other minor volatile compounds than unspoiled hams. The sensorial analysis showed that the spoilage level of hams correlated with several volatile compounds, most of them associated with Gram-positive catalase positive cocci and Enterobacteriaceae counts. Cyclic compounds such as cyclohexanone, some ethers, and pyrazines should be considered as indicators to monitor incipient microbial deep spoilage in the elaboration of this meat product.

  3. Using So-Called Mind-Body Practices to Promote Youths' Well-Being: Reflections on Therapeutic Outcomes, Strategies, and Processes

    ERIC Educational Resources Information Center

    Renshaw, Tyler L.

    2016-01-01

    The present article provides commentary on this pioneering special issue covering the usefulness of so-called mind-body practices with youth and in schools. I begin by addressing the way we talk about this approach to practice, describing a few undesirable consequences that can follow from using the mind-body moniker adopted from the world of…

  4. INFLUENCE OF SURFACTANTS ON MICROBIAL DEGRADATION OF ORGANIC COMPOUNDS

    EPA Science Inventory

    Surfactants have the ability to increase aqueous concentrations of poorly soluble compounds and interfacial areas between immiscible fluids, thus potentially improving the accessibility of these substrates to microorganisms. However, both enhancements and inhibitions of biodegrad...

  5. Microbial transformations of natural organic compounds and radionuclides in subsurface environments

    SciTech Connect

    Francis, A.J.

    1985-10-01

    A major national concern in the subsurface disposal of energy wastes is the contamination of ground and surface waters by waste leachates containing radionuclides, toxic metals, and organic compounds. Microorganisms play an important role in the transformation of organic compounds, radionuclides, and toxic metals present in the waste and affect their mobility in subsurface environments. Microbial processes involved in dissolution, mobilization, and immobilization of toxic metals under aerobic and anaerobic conditions are briefly reviewed. Metal complexing agents and several organic acids produced by microbial action affect mobilization of radionuclides and toxic metals in subsurface environments. Information on the persistence of and biodegradation rates of synthetic as well as microbiologically produced complexing agents is scarce but important in determining the mobility of metal organic complexes in subsoils. Several gaps in knowledge in the area of microbial transformation of naturally occurring organics, radionuclides, and toxic metals have been identified, and further basic research has been suggested. 31 refs., 1 fig., 3 tabs.

  6. Microbial degradation of lignin-derived compounds under anaerobic conditions

    SciTech Connect

    Colberg, P.J.

    1983-01-01

    Lignin is the second most abundant form of organic carbon in the biosphere. Recent laboratory studies indicate that a large fraction of polymeric lignin is incompletely degraded by aerobic lignolytic microorganisms and is subsequently released as lignin fragments of reduced molecular size. If such lignin-derived compounds become available in the anaerobic environment, they may serve as potential sources of organic carbon for organisms which release methane precursors. The methanogenic bacteria, in turn, serve as terminal members of the anaerobic food chain, and thus, limit the accumulation of organic carbon in anaerobic sinks. This thesis presents evidence to suggest that lignin-derived compounds which have molecular sizes greater than those of single-ring aromatic compounds (MW > 200) are anaerobically biodegradable to methane. This research involved development of selective enrichment cultures capable of utilizing oligolignols as sole carbon sources. Radiolabeled water-soluble catabolites, released during aerobic lignin degradation by the white rot fungus Phanerochaete chrysosporium, were subjected to anaerobic degradation. The second phase of work involved capillary gas chromatographic analyses of enrichment cultures fed a /sup 14/C-labeled, lignin-derived substrate of average molecular weight 600. 2-Bromoethanesulfonic acid was used to inhibit methane formation and enhance buildup of metabolic intermediates, resulting in the accumulation of volatile fatty acids, phenylacetate, benzoate, catechol, 3-phenyl-propionate, vanillin, syringic acid, vanillic acid, ferulic acid, and caffeic acid. A conceptual model for the anaerobic degradation of two- and three-ring lignin fragments is proposed which overlaps both the ferulate and benzoate degradation pathways at the level of single-ring aromatic compounds.

  7. Microbial Production of Amino Acid-Related Compounds.

    PubMed

    Wendisch, Volker F

    2016-11-22

    Corynebacterium glutamicum is the workhorse of the production of proteinogenic amino acids used in food and feed biotechnology. After more than 50 years of safe amino acid production, C. glutamicum has recently also been engineered for the production of amino acid-derived compounds, which find various applications, e.g., as synthons for the chemical industry in several markets including the polymer market. The amino acid-derived compounds such as non-proteinogenic ω-amino acids, α,ω-diamines, and cyclic or hydroxylated amino acids have similar carbon backbones and functional groups as their amino acid precursors. Decarboxylation of amino acids may yield ω-amino acids such as β-alanine, γ-aminobutyrate, and δ-aminovalerate as well as α,ω-diamines such as putrescine and cadaverine. Since transamination is the final step in several amino acid biosynthesis pathways, 2-keto acids as immediate amino acid precursors are also amenable to production using recombinant C. glutamicum strains. Approaches for metabolic engineering of C. glutamicum for production of amino acid-derived compounds will be described, and where applicable, production from alternative carbon sources or use of genome streamline will be referred to. The excellent large-scale fermentation experience with C. glutamicum offers the possibility that these amino acid-derived speciality products may enter large-volume markets.

  8. Microbial Volatile Organic Compound Emissions from Stachybotrys chartarum growing on Gypsum Wallboard and Ceiling tile

    EPA Science Inventory

    This study compared seven toxigenic strains of S. chartarum found in water-damaged buildings to characterize the microbial volatile organic compound (MVOC) emissions profile while growing on gypsum wallboard (W) and ceiling tile (C) coupons. The inoculated coupons with their sub...

  9. Lesions caused in suckling mice by certain viruses isolated from cases of so called non-paralytic poliomyelitis and of pleurodynia.

    PubMed

    PAPPENHEIMER, A M; DANIELS, J B; CHEEVER, F S; WELLER, T H

    1950-08-01

    A STUDY HAS BEEN MADE OF THE LESIONS PRODUCED IN SUCKLING MICE BY THE FOLLOWING VIRUSES: Powers, Matulaitis, DeMole, Kine, McCarthy, Conn. 5, Ohio R, High Point, WS No. 4, EMC, and Col. SK. Pathologic alterations have been found in myocardium, lungs, liver, pancreas, thymus, brain and spinal cord, adipose tissue, and skeletal muscles. A comparison of the lesions produced by the individual strains has disclosed certain differential features which are discussed in detail. Within the group of so called Coxsackie viruses, myositis has not proved to be a constant finding, and it may occur in suckling mice infected with other types of virus.

  10. Discovery of New Compounds Active against Plasmodium falciparum by High Throughput Screening of Microbial Natural Products.

    PubMed

    Pérez-Moreno, Guiomar; Cantizani, Juan; Sánchez-Carrasco, Paula; Ruiz-Pérez, Luis Miguel; Martín, Jesús; El Aouad, Noureddine; Pérez-Victoria, Ignacio; Tormo, José Rubén; González-Menendez, Víctor; González, Ignacio; de Pedro, Nuria; Reyes, Fernando; Genilloud, Olga; Vicente, Francisca; González-Pacanowska, Dolores

    2016-01-01

    Due to the low structural diversity within the set of antimalarial drugs currently available in the clinic and the increasing number of cases of resistance, there is an urgent need to find new compounds with novel modes of action to treat the disease. Microbial natural products are characterized by their large diversity provided in terms of the chemical complexity of the compounds and the novelty of structures. Microbial natural products extracts have been underexplored in the search for new antiparasitic drugs and even more so in the discovery of new antimalarials. Our objective was to find new druggable natural products with antimalarial properties from the MEDINA natural products collection, one of the largest natural product libraries harboring more than 130,000 microbial extracts. In this work, we describe the optimization process and the results of a phenotypic high throughput screen (HTS) based on measurements of Plasmodium lactate dehydrogenase. A subset of more than 20,000 extracts from the MEDINA microbial products collection has been explored, leading to the discovery of 3 new compounds with antimalarial activity. In addition, we report on the novel antiplasmodial activity of 4 previously described natural products.

  11. Volatile compounds originating from mixed microbial cultures on building materials under various humidity conditions.

    PubMed

    Korpi, A; Pasanen, A L; Pasanen, P

    1998-08-01

    We examined growth of mixed microbial cultures (13 fungal species and one actinomycete species) and production of volatile compounds (VOCs) in typical building materials in outside walls, separating walls, and bathroom floors at various relative humidities (RHs) of air. Air samples from incubation chambers were adsorbed on Tenax TA and dinitrophenylhydrazine cartridges and were analyzed by thermal desorption-gas chromatography and high-performance liquid chromatography, respectively. Metabolic activity was measured by determining CO2 production, and microbial concentrations were determined by a dilution plate method. At 80 to 82% RH, CO2 production did not indicate that microbial activity occurred, and only 10% of the spores germinated, while slight increases in the concentrations of some VOCs were detected. All of the parameters showed that microbial activity occurred at 90 to 99% RH. The microbiological analyses revealed weak microbial growth even under drying conditions (32 to 33% RH). The main VOCs produced on the building materials studied were 3-methyl-1-butanol, 1-pentanol, 1-hexanol, and 1-octen-3-ol. In some cases fungal growth decreased aldehyde emissions. We found that various VOCs accompany microbial activity but that no single VOC is a reliable indicator of biocontamination in building materials.

  12. Microbial remediation of nitro-aromatic compounds: an overview.

    PubMed

    Kulkarni, Meenal; Chaudhari, Ambalal

    2007-10-01

    Nitro-aromatic compounds are produced by incomplete combustion of fossil fuel or nitration reactions and are used as chemical feedstock for synthesis of explosives, pesticides, herbicides, dyes, pharmaceuticals, etc. The indiscriminate use of nitro-aromatics in the past due to wide applications has resulted in inexorable environmental pollution. Hence, nitro-aromatics are recognized as recalcitrant and given Hazardous Rating-3. Although several conventional pump and treat clean up methods are currently in use for the removal of nitro-aromatics, none has proved to be sustainable. Recently, remediation by biological systems has attracted worldwide attention to decontaminate nitro-aromatics polluted sources. The incredible versatility inherited in microbes has rendered these compounds as a part of the biogeochemical cycle. Several microbes catalyze mineralization and/or non-specific transformation of nitro-aromatics either by aerobic or anaerobic processes. Aerobic degradation of nitro-aromatics applies mainly to mono-, dinitro-derivatives and to some extent to poly-nitro-aromatics through oxygenation by: (i) monooxygenase, (ii) dioxygenase catalyzed reactions, (iii) Meisenheimer complex formation, and (iv) partial reduction of aromatic ring. Under anaerobic conditions, nitro-aromatics are reduced to amino-aromatics to facilitate complete mineralization. The nitro-aromatic explosives from contaminated sediments are effectively degraded at field scale using in situ bioremediation strategies, while ex situ techniques using whole cell/enzyme(s) immobilized on a suitable matrix/support are gaining acceptance for decontamination of nitrophenolic pesticides from soils at high chemical loading rates. Presently, the qualitative and quantitative performance of biological approaches of remediation is undergoing improvement due to: (i) knowledge of catabolic pathways of degradation, (ii) optimization of various parameters for accelerated degradation, and (iii) design of microbe

  13. The cytokeratin filament-aggregating protein filaggrin is the target of the so-called "antikeratin antibodies," autoantibodies specific for rheumatoid arthritis.

    PubMed Central

    Simon, M; Girbal, E; Sebbag, M; Gomès-Daudrix, V; Vincent, C; Salama, G; Serre, G

    1993-01-01

    In rheumatoid arthritis (RA), the high diagnostic value of serum antibodies to the stratum corneum of rat esophagus epithelium has been widely reported. These so-called "antikeratin antibodies," detected by indirect immunofluorescence, were found to be autoantibodies since they also labeled human epidermis. Despite their name, the actual target of these autoantibodies was not known. In this study, a 40-kD protein (designated as 40K), extracted from human epidermis and specifically immunodetected by 75% of RA sera, was purified and identified as a neutral/acidic isoform of basic filaggrin, a cytokeratin filament-aggregating protein, by peptide mapping studies and by the following evidences: (a) mAbs specific for filaggrin reacted with the 40K protein; (b) the autoantibodies, affinity-purified from RA sera on the 40K protein, immunodetected purified filaggrin; (c) the reactivity of RA sera to the 40K protein was abolished after immunoadsorption with purified filaggrin; (d) the 40K protein and filaggrin had similar amino acid compositions. Furthermore, autoantibodies against the 40K protein and the so-called "antikeratin antibodies" were shown, by immunoadsorption experiments, to be largely the same. The identification of filaggrin as a RA-specific autoantigen could contribute to the understanding of the pathogenesis of this disease and, ultimately, to the development of methods for preventing the autoimmune response. Images PMID:7690781

  14. A Case of Hyalinizing Clear Cell Carcinoma, So-Called Clear Cell Carcinoma, Not Otherwise Specified, of the Minor Salivary Glands of the Buccal Mucosa

    PubMed Central

    Yamanishi, Takahiro; Kutsuma, Kiwako; Masuyama, Keisuke

    2015-01-01

    Hyalinizing clear cell carcinoma (HCCC), so-called clear cell carcinoma, not otherwise specified (CCC (NOS)), of the salivary glands is a rare and low-grade malignant tumor. We report a case of HCCC so-called CCC (NOS) (referred to as HCCC) of the minor salivary gland of the buccal mucosa. A 52-year-old woman had presented with a gradually growing and indolent mass in the right buccal mucosa for about two years. The first biopsy histopathologically suggested the possibility of malignancy derived from the minor salivary glands. A month later, she visited our hospital. The tumor measured approximately 1.5 cm in diameter and was elastic hard, smooth, and well movable. Image examinations demonstrated internal homogeneity of the lesion, which had a smooth margin, in the right buccal mucosa. Complete tumor resection followed by covering with a polyglycolic acid sheet and fibrin glue spray was performed without surgical flap reconstruction. Histopathological findings revealed proliferating tumor cells with clear cytoplasm surrounded by hyalinizing stroma in the submucosal minor salivary glands. Immunohistochemical stains revealed these tumor cells to be positive for epithelial cell markers but negative for myoepithelial ones. These findings confirmed the diagnosis of HCCC. Good wound healing and no evidence of local recurrence and metastasis have been shown since surgery. PMID:26600962

  15. Newly Discovered Paleocene and Eocene Rocks near Fairfield, California, and Correlation with Rocks in Vaca Valley and the So-Called Martinez Formation or Stage

    USGS Publications Warehouse

    Brabb, Earl E.; Ristau, Donn; Bukry, David; McDougall, Kristin; Almgren, Alvin A.; Saul, LouElla; Sanfilippo, Annika

    2008-01-01

    Discovery of a 3-foot thick sandstone bed with abundant Turritellid gastropods of late Paleocene age about 4 miles northeast of Fairfield and on the southwest flank of Cement Hill, Solano County provides an opportunity to reevaluate the relationships of lower Tertiary formations in this part of California. Cement Hill is named for travertine deposits in and on top of sandstone of Late Cretaceous age. In this report, the current study area where the Paleocene fossils were recently discovered is referred to as lower Cement Hill and is located in section 7 of the U.S. Geological Survey Fairfield North 7.5-minute quadrangle, Township 5 North, Range 1 West. Lower Cement Hill is about 23 miles north of the so-called Martinez 'formation' or stage area (Weaver and others, 1941) of late Paleocene age near Martinez. The Martinez 'formation' and stage have played a significant role in the development of early Tertiary stratigraphy in this part of California. The discovery of correlative rocks at Cement Hill was unsuspected and may be helpful in defining the extent of this so-called formation or stage. Coccolith identification and correlations are by David Bukry, foraminifer identifications and correlations by Alvin Almgren and Kristin McDougall, gastropod identification and correlation by LouElla Saul, and Radiolaria identifications and correlations are by Annika Sanfilippo.

  16. [Effects of Organic and Inorganic Slow-Release Compound Fertilizer on Different Soils Microbial Community Structure].

    PubMed

    Wang, Fei; Yuan, Ting; Gu, Shou-kuan; Wang, Zheng-yin

    2015-04-01

    As a new style fertilizer, slow-control release fertilizer had been an important subject in recent years, but few researches were about soil microbial community structure diversity. Phospholipid fatty acid method was used to determined the microbial community structure diversity of acid soil and slight alkaline soil applied with slow-release compound fertilizer (SRF), chemical fertilizer (CF) and common compound fertilizer (CCF) at the 10th, 30th, 60th and 90th day under the constant temperature incubation condition. Results indicated that various bacteria (i. e 13:0, i14:0,14:0, i15:0, a15:0, i16:0, 16:12OH, 16:1w5c,16:0, i17:0, a17:0, cy17:0, 17:02OH, i18:0, 18:0 and cy19:0w8c), two actinomycetes (10Me17:0 and 10Me18:0) and only one fungus (18:1 w9c) were detected in two soils after applying slow-release compound fertilizer and other fertilizers during the whole incubation period. SRF could significantly increase the fungi PLFA content by 8.3% and 6.8% at the early stage (the 10th day and 30th day) compared with CF, as well as significantly increase by 22.7% and 17.1% at the late stage (the 60th day and 90th day) compared with CCF in acid soil. SRF significantly increased bacteria, fungi and gram positive bacteria compared with CF and CCF in incubation period (except at the 30th day) in slight alkaline soil. SRF could significantly improve the ratio of normal saturated fatty acid and monounsaturated fatty acid at the 30th day and 90th days in acid soil compared with no fertilizer (CK), CF and CCF, while as to slight alkaline soil, SRF was significantly greater than that of CK, CF and CCF only at the 60th day. SRF could significantly decrease the ratio of iso PLFA and anteiso PLFA in acid soil (in 30-90 days) and slight alkaline soil (in 10-60 days). For two soils PLFA varieties, contents and ratios of microbial community, slow-release compound fertilizer increased soil microbial PLFA varieties and contents, and decreased the influence to microbial survival

  17. Microbial degradation of chitin waste for production of chitosanase and food related bioactive compounds.

    PubMed

    Sinha, S; Chand, S; Tripathi, P

    2014-01-01

    Ecological samples rich in microbial diversity like cow dung, legume rhizosphere, fish waste and garden soil were used for isolation of chitosan-degrading microorganisms. Selected isolates were used for production of chitosanase and food related bioactive compounds by conversion of biowaste. Production of glucosamine (Gln), N-acetylglucosamine (NAG), chitooligosaccharides (COS), antioxidants, antibacterial compounds and prebiotics was carried out by microbial fermentation of biowaste. The highest chitosanase activity (8 U/mL) was observed in Aspergillus sp. isolated from fish market waste and it could produce Gln and NAG while Streptomyces sp. isolated from garden soil was able to produce COS along with Gln and NAG. Radical scavenging activity was observed in culture supernatants of 35% of studied isolates, and 20% isolates secreted compounds which showed positive effect on growth of Bifidobacterium. Antibacterial compounds were produced by 40% of selected isolates and culture supernatants of two microbial isolates, Streptomyces zaomyceticus C6 and one of garden soil isolates, were effective against both gram positive and negative bacteria.

  18. Microbial communities related to volatile organic compound emission in automobile air conditioning units.

    PubMed

    Diekmann, Nina; Burghartz, Melanie; Remus, Lars; Kaufholz, Anna-Lena; Nawrath, Thorben; Rohde, Manfred; Schulz, Stefan; Roselius, Louisa; Schaper, Jörg; Mamber, Oliver; Jahn, Dieter; Jahn, Martina

    2013-10-01

    During operation of mobile air conditioning (MAC) systems in automobiles, malodours can occur. We studied the microbial communities found on contaminated heat exchanger fins of 45 evaporators from car MAC systems which were operated in seven different regions of the world and identified corresponding volatile organic compounds. Collected biofilms were examined by scanning electron microscopy and fluorescent in situ hybridization. The detected bacteria were loosely attached to the metal surface. Further analyses of the bacteria using PCR-based single-strand conformation polymorphism and sequencing of isolated 16S rRNA gene fragments identified highly divergent microbial communities with multiple members of the Alphaproteobacteriales, Methylobacteria were the prevalent bacteria. In addition, Sphingomonadales, Burkholderiales, Bacillales, Alcanivorax spp. and Stenotrophomonas spp. were found among many others depending on the location the evaporators were operated. Interestingly, typical pathogenic bacteria related to air conditioning systems including Legionella spp. were not found. In order to determine the nature of the chemical compounds produced by the bacteria, the volatile organic compounds were examined by closed loop stripping analysis and identified by combined gas chromatography/mass spectrometry. Sulphur compounds, i.e. di-, tri- and multiple sulphides, acetylthiazole, aromatic compounds and diverse substituted pyrazines were detected. Mathematical clustering of the determined microbial community structures against their origin identified a European/American/Arabic cluster versus two mainly tropical Asian clusters. Interestingly, clustering of the determined volatiles against the origin of the corresponding MAC revealed a highly similar pattern. A close relationship of microbial community structure and resulting malodours to the climate and air quality at the location of MAC operation was concluded.

  19. Inhibitory Effect of Furanic and Phenolic Compounds on Exoelectrogenesis in a Microbial Electrolysis Cell Bioanode

    SciTech Connect

    Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

    2016-09-09

    Furanic and phenolic compounds are 20 lignocellulose-derived compounds known to inhibit to H2- and ethanol- producing microorganisms in dark fermentation. Bioelectrochemical conversion of furanic and phenolic compounds to electricity or H2 has recently been demonstrated as a productive method to use these compounds. However, potential inhibitory effect of furanic and phenolic compounds on exoelectrogenesis in bioelectrochemical systems is not well understood. This study systematically investigated the inhibitory effect of furfural (FF), 5-hydroxymethylfurfural (HMF), syringic acid (SA), vanillic acid (VA), and 4-hydroxybenzoic acid (HBA) on exoelectrogenesis in the bioanode of a microbial electrolysis cell. A mixture of these five compounds at an increasing initial total concentration from 0.8 to 8.0 g/L resulted in current decrease up to 91%. The observed inhibition primarily affected exoelectrogenesis, instead of non-exoelectrogenic biotransformation pathways (e.g., fermentation) of the five compounds. Furthermore, the parent compounds at a high concentration, as opposed to their biotransformation products, were responsible for the observed inhibition. Tests with individual compounds show that all five parent compounds contributed to the observed inhibition by the mixture. The IC50 (concentration resulting in 50% current decrease) was estimated as 2.7 g/L for FF, 3.0 g/L for HMF, 1.9 g/L for SA, 2.1 g/L for VA and 2.0 g/L for HBA. Nevertheless, these compounds below their non-inhibitory concentrations jointly resulted in significant inhibition as a mixture. Catechol and phenol, which were persistent biotransformation products of the mixture, inhibited exoelectrogens at high concentrations, but to a lesser extent than the parent compounds. Recovery of exoelectrogenesis from inhibition by all compounds was observed, except for catechol, which resulted in irreversible inhibition. The reversibility of inhibition, as well as the observed difference in recovery rates

  20. Effects of furan derivatives and phenolic compounds on electricity generation in microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Catal, Tunc; Fan, Yanzhen; Li, Kaichang; Bermek, Hakan; Liu, Hong

    Lignocellulosic biomass is an attractive fuel source for MFCs due to its renewable nature and ready availability. Furan derivatives and phenolic compounds could be potentially formed during the pre-treatment process of lignocellulosic biomass. In this study, voltage generation from these compounds and the effects of these compounds on voltage generation from glucose in air-cathode microbial fuel cells (MFCs) were examined. Except for 5-hydroxymethyl furfural (5-HMF), all the other compounds tested were unable to be utilized directly for electricity production in MFCs in the absence of other electron donors. One furan derivate, 5-HMF and two phenolic compounds, trans-cinnamic acid and 3,5-dimethoxy-4-hydroxy-cinnamic acid did not affect electricity generation from glucose at a concentration up to 10 mM. Four phenolic compounds, including syringaldeyhde, vanillin, trans-4-hydroxy-3-methoxy, and 4-hydroxy cinnamic acids inhibited electricity generation at concentrations above 5 mM. Other compounds, including 2-furaldehyde, benzyl alcohol and acetophenone, inhibited the electricity generation even at concentrations less than 0.2 mM. This study suggests that effective electricity generation from the hydrolysates of lignocellulosic biomass in MFCs may require the employment of the hydrolysis methods with low furan derivatives and phenolic compounds production, or the removal of some strong inhibitors prior to the MFC operation, or the improvement of bacterial tolerance against these compounds through the enrichment of new bacterial cultures or genetic modification of the bacterial strains.

  1. The effects of abiotic and biotic environmental components on the microbial mineralization of selected xenobiotic compounds in soils

    SciTech Connect

    Knaebel, D.B.

    1990-01-01

    This research investigated the effects of environmental components on the microbial mineralization of xenobiotic compounds in soils. The soils' chemical and physical characteristics, microbial community structure, organic and inorganic components, and other associated biota (plants) were examined for their effects on the biodegradation process. The biodegradation of {sup 14}C foreign, synthetic ({double bond} xenobiotic) compounds was measured by quantifying {sup 14} CO{sub 2} production over time. Mineralization kinetics were estimated by first-order and 3/2 order mineralization models. The compounds displayed different mineralization kinetics in the different soils, which were due to nature of the xenobiotic chemical and to abiotic and biotic soil characteristics. Specific soil components (montmorillonite, humic acids and fulvic acids) inhibited mineralization. Other soil components (sand, illite, kaolinite) had less effect on the biodegradation process. Modified soil microbial communities mineralized the compounds differently. Bacteria-enhanced soils metabolized the compounds to greater extents than the fungi-enhanced soils, which both mineralized the compounds more than actinomycete-enhanced soils. However, the rates of mineralization were only significantly different between the bacteria-enhanced soils and the actinomycete-enhanced soil. Plants significantly increased soil microbial biomass and activity, and stimulated the rate of microbial mineralization of xenobiotic compounds. However, they had no effect on the total amounts of mineralization. In summary, these diverse abiotic and biotic environmental components exerted tremendous influences on the microbial turnover of xenobiotic compounds in soils. Therefore, these components should be considered when modeling the fate of xenobiotic chemicals in the environment.

  2. Microbial colonization of biopolymeric thin films containing natural compounds and antibiotics fabricated by MAPLE

    NASA Astrophysics Data System (ADS)

    Cristescu, R.; Surdu, A. V.; Grumezescu, A. M.; Oprea, A. E.; Trusca, R.; Vasile, O.; Dorcioman, G.; Visan, A.; Socol, G.; Mihailescu, I. N.; Mihaiescu, D.; Enculescu, M.; Chifiriuc, M. C.; Boehm, R. D.; Narayan, R. J.; Chrisey, D. B.

    2015-05-01

    Although a great number of antibiotics are currently available, they are often rendered ineffective by the ability of microbial strains to develop genetic resistance and to grow in biofilms. Since many antimicrobial agents poorly penetrate biofilms, biofilm-associated infections often require high concentrations of antimicrobial agents for effective treatment. Among the various strategies that may be used to inhibit microbial biofilms, one strategy that has generated significant interest involves the use of bioactive surfaces that are resistant to microbial colonization. In this respect, we used matrix assisted pulsed laser evaporation (MAPLE) involving a pulsed KrF* excimer laser source (λ = 248 nm, τ = 25 ns, ν = 10 Hz) to obtain thin composite biopolymeric films containing natural (flavonoid) or synthetic (antibiotic) compounds as bioactive substances. Chemical composition and film structures were investigated by Fourier transform infrared spectroscopy and X-ray diffraction. Films morphology was studied by scanning electron microscopy and transmission electron microscopy. The antimicrobial assay of the microbial biofilms formed on these films was assessed by the viable cell counts method. The flavonoid-containing thin films showed increased resistance to microbial colonization, highlighting their potential to be used for the design of anti-biofilm surfaces.

  3. Microbial degradation of alpha-cypermethrin in soil by compound-specific stable isotope analysis.

    PubMed

    Xu, Zemin; Shen, Xiaoli; Zhang, Xi-Chang; Liu, Weiping; Yang, Fangxing

    2015-09-15

    To assess microbial degradation of alpha-cypermethrin in soil, attenuation of alpha-cypermethrin was investigated by compound-specific stable isotope analysis. The variations of the residual concentrations and stable carbon isotope ratios of alpha-cypermethrin were detected in unsterilized and sterilized soils spiked with alpha-cypermethrin. After an 80 days' incubation, the concentrations of alpha-cypermethrin decreased to 0.47 and 3.41 mg/kg in the unsterilized soils spiked with 2 and 10 mg/kg, while those decreased to 1.43 and 6.61 mg/kg in the sterilized soils. Meanwhile, the carbon isotope ratios shifted to -29.14 ± 0.22‰ and -29.86 ± 0.33‰ in the unsterilized soils spiked with 2 and 10 mg/kg, respectively. The results revealed that microbial degradation contributed to the attenuation of alpha-cypermethrin and induced the carbon isotope fractionation. In order to quantitatively assess microbial degradation, a relationship between carbon isotope ratios and residual concentrations of alpha-cypermethrin was established according to Rayleigh equation. An enrichment factor, ϵ = -1.87‰ was obtained, which can be employed to assess microbial degradation of alpha-cypermethrin. The significant carbon isotope fractionation during microbial degradation suggests that CSIA is a proper approach to qualitatively detect and quantitatively assess the biodegradation during attenuation process of alpha-cypermethrin in the field.

  4. Microbial Electrosynthesis: Feeding Microbes Electricity To Convert Carbon Dioxide and Water to Multicarbon Extracellular Organic Compounds

    PubMed Central

    Nevin, Kelly P.; Woodard, Trevor L.; Franks, Ashley E.; Summers, Zarath M.; Lovley, Derek R.

    2010-01-01

    The possibility of providing the acetogenic microorganism Sporomusa ovata with electrons delivered directly to the cells with a graphite electrode for the reduction of carbon dioxide to organic compounds was investigated. Biofilms of S. ovata growing on graphite cathode surfaces consumed electrons with the reduction of carbon dioxide to acetate and small amounts of 2-oxobutyrate. Electrons appearing in these products accounted for over 85% of the electrons consumed. These results demonstrate that microbial production of multicarbon organic compounds from carbon dioxide and water with electricity as the energy source is feasible. PMID:20714445

  5. Microbial electrosynthesis: feeding microbes electricity to convert carbon dioxide and water to multicarbon extracellular organic compounds.

    PubMed

    Nevin, Kelly P; Woodard, Trevor L; Franks, Ashley E; Summers, Zarath M; Lovley, Derek R

    2010-05-25

    The possibility of providing the acetogenic microorganism Sporomusa ovata with electrons delivered directly to the cells with a graphite electrode for the reduction of carbon dioxide to organic compounds was investigated. Biofilms of S. ovata growing on graphite cathode surfaces consumed electrons with the reduction of carbon dioxide to acetate and small amounts of 2-oxobutyrate. Electrons appearing in these products accounted for over 85% of the electrons consumed. These results demonstrate that microbial production of multicarbon organic compounds from carbon dioxide and water with electricity as the energy source is feasible.

  6. Comparative studies on peptides representing the so-called tachykinin-like region of the Alzheimer Abeta peptide [Abeta(25-35)].

    PubMed Central

    El-Agnaf, O M; Irvine, G B; Fitzpatrick, G; Glass, W K; Guthrie, D J

    1998-01-01

    In an attempt to answer the question of whether or not the so-called tachykinin-like region of the Alzheimer beta-amyloid protein [Abeta(25-35)] can act as a tachykinin, the sequences Abeta(25-35), Abeta(25-35)amide and their norleucine-35 and phenylalanine-31 analogues were synthesized. These peptides were examined with ligand binding studies, electron microscopy, CD and NMR. In all cases some differences were found between the Abeta(25-35) analogue and the corresponding Phe31 peptide. In addition, in ligand displacement studies on tachykinin NK1 receptors, only the Phe31 analogue showed activity comparable to that of genuine tachykinins. We conclude that peptides based on Abeta(25-35) but with a Phe residue at position 31 do display properties typical of a tachykinin, but that peptides with Ile at this position do not. PMID:9820820

  7. ADAPTATION OF AQUIFER MICROBIAL COMMUNITIES TO THE BIODEGRADATION OF XENOBIOTIC COMPOUNDS: INFLUENCE OF SUBSTRATE CONCENTRATION AND PREEXPOSURE

    EPA Science Inventory

    Studies were conducted to examine the adaptation response of aquifer microbial communities to xenobiotic compounds and the influence of chemical preexposure in the laboratory and in situ on adaptation. Adaptation and biodegradation were assessed as mineralization and cellular inc...

  8. Energetic Limitations on Microbial Respiration of Organic Compounds using Aqueous Fe(III) Complexes

    NASA Astrophysics Data System (ADS)

    Naughton, H.; Fendorf, S. E.

    2015-12-01

    Soil organic matter constitutes up to 75% of the terrestrial carbon stock. Microorganisms mediate the breakdown of organic compounds and the return of carbon to the atmosphere, predominantly through respiration. Microbial respiration requires an electron acceptor and an electron donor such as small fatty acids, organic acids, alcohols, sugars, and other molecules that differ in oxidation state of carbon. Carbon redox state affects how much energy is required to oxidize a molecule through respiration. Therefore, different organic compounds should offer a spectrum of energies to respiring microorganisms. However, microbial respiration has traditionally focused on the availability and reduction potential of electron acceptors, ignoring the organic electron donor. We found through incubation experiments that the organic compound serving as electron donor determined how rapidly Shewanella putrefaciens CN32 respires organic substrate and the extent of reduction of the electron acceptor. We simulated a range of energetically favorable to unfavorable electron acceptors using organic chelators bound to Fe(III) with equilibrium stability constants ranging from log(K) of 11.5 to 25.0 for the 1:1 complex, where more stable complexes are less favorable for microbial respiration. Organic substrates varied in nominal oxidation state of carbon from +2 to -2. The most energetically favorable substrate, lactate, promoted up to 30x more rapid increase in percent Fe(II) compared to less favorable substrates such as formate. This increased respiration on lactate was more substantial with less stable Fe(III)-chelate complexes. Intriguingly, this pattern contradicts respiration rate predicted by nominal oxidation state of carbon. Our results suggest that organic substrates will be consumed so long as the energetic toll corresponding to the electron donor half reaction is counterbalanced by the energy available from the electron accepting half reaction. We propose using the chemical

  9. Adaptation to and biodegradation of xenobiotic compounds by microbial communities from a pristine aquifer

    SciTech Connect

    Aelion, C.M.; Swindoll, C.M.; Pfaender, F.K.

    1987-09-01

    The ability of subsurface microbial communities to adapt to the biodegradation of xenobiotic compounds was examined in aquifer solids samples from a pristine aquifer. An increase in the rates of mineralization of /sup 14/C labeled substrates with exposure was used as an indication of adaptation. For some compounds, such as chlorobenzene and 1,2,4-trichlorobenzene, slight mineralization was observed but no adaptation was apparent during incubations of over 8 months. Other compounds demonstrated three patterns of response. For m-cresol, m-aminophenol, and aniline intermediate rates of biodegradation and a linear increase in the percent mineralized with time were observed. Phenol, p-chlorophenol, and ethylene dibromide were rapidly metabolized initially, with a nonlinear increase in the percent mineralized with time, indicating that the community was already adapted to the biodegradation of these compounds. Only p-nitrophenol demonstrated a typical adaptation response. In different samples of soil from the same layer in the aquifer, the adaptation period to p-nitrophenol varied from a few days to as long as 6 weeks. In most cases the concentration of xenobiotic added, over the range from a few nanograms to micrograms per gram, made no difference in the response. Most-probably-number counts demonstrated that adaptation is accompanied by an increase in specific degrader numbers. This study has shown that diverse patterns of response occur in the subsurface microbial community.

  10. A novel aromatic oil compound inhibits microbial overgrowth on feet: a case study

    PubMed Central

    Misner, Bill D

    2007-01-01

    Background Athlete's Foot (Tinea pedis) is a form of ringworm associated with highly contagious yeast-fungi colonies, although they look like bacteria. Foot bacteria overgrowth produces a harmless pungent odor, however, uncontrolled proliferation of yeast-fungi produces small vesicles, fissures, scaling, and maceration with eroded areas between the toes and the plantar surface of the foot, resulting in intense itching, blisters, and cracking. Painful microbial foot infection may prevent athletic participation. Keeping the feet clean and dry with the toenails trimmed reduces the incidence of skin disease of the feet. Wearing sandals in locker and shower rooms prevents intimate contact with the infecting organisms and alleviates most foot-sensitive infections. Enclosing feet in socks and shoes generates a moisture-rich environment that stimulates overgrowth of pungent both aerobic bacteria and infectious yeast-fungi. Suppression of microbial growth may be accomplished by exposing the feet to air to enhance evaporation to reduce moistures' growth-stimulating effect and is often neglected. There is an association between yeast-fungi overgrowths and disabling foot infections. Potent agents virtually exterminate some microbial growth, but the inevitable presence of infection under the nails predicts future infection. Topical antibiotics present a potent approach with the ideal agent being one that removes moisture producing antibacterial-antifungal activity. Severe infection may require costly prescription drugs, salves, and repeated treatment. Methods A 63-y female volunteered to enclose feet in shoes and socks for 48 hours. Aerobic bacteria and yeast-fungi counts were determined by swab sample incubation technique (1) after 48-hours feet enclosure, (2) after washing feet, and (3) after 8-hours socks-shoes exposure to a aromatic oil powder-compound consisting of arrowroot, baking soda, basil oil, tea tree oil, sage oil, and clove oil. Conclusion Application of this

  11. Biotransformation of Furanic and Phenolic Compounds with Hydrogen Gas Production in a Microbial Electrolysis Cell.

    PubMed

    Zeng, Xiaofei; Borole, Abhijeet P; Pavlostathis, Spyros G

    2015-11-17

    Furanic and phenolic compounds are problematic byproducts resulting from the breakdown of lignocellulosic biomass during biofuel production. The capacity of a microbial electrolysis cell (MEC) to produce hydrogen gas (H2) using a mixture of two furanic (furfural, FF; 5-hydroxymethyl furfural, HMF) and three phenolic (syringic acid, SA; vanillic acid, VA; and 4-hydroxybenzoic acid, HBA) compounds as the substrate in the bioanode was assessed. The rate and extent of biotransformation of the five compounds and efficiency of H2 production, as well as the structure of the anode microbial community, were investigated. The five compounds were completely transformed within 7-day batch runs and their biotransformation rate increased with increasing initial concentration. At an initial concentration of 1200 mg/L (8.7 mM) of the mixture of the five compounds, their biotransformation rate ranged from 0.85 to 2.34 mM/d. The anode Coulombic efficiency was 44-69%, which is comparable to that of wastewater-fed MECs. The H2 yield varied from 0.26 to 0.42 g H2-COD/g COD removed in the anode, and the bioanode volume-normalized H2 production rate was 0.07-0.1 L/L-d. The biotransformation of the five compounds took place via fermentation followed by exoelectrogenesis. The major identified fermentation products that did not transform further were catechol and phenol. Acetate was the direct substrate for exoelectrogenesis. Current and H2 production were inhibited at an initial substrate concentration of 1200 mg/L, resulting in acetate accumulation at a much higher level than that measured in other batch runs conducted with a lower initial concentration of the five compounds. The anode microbial community consisted of exoelectrogens, putative degraders of the five compounds, and syntrophic partners of exoelectrogens. The MEC H2 production demonstrated in this study is an alternative to the currently used process of reforming natural gas to supply H2 needed to upgrade bio-oils to stable

  12. Biotransformation of furanic and phenolic compounds with hydrogen gas production in a microbial electrolysis cell

    DOE PAGES

    Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

    2015-10-27

    In this study, furanic and phenolic compounds are problematic byproducts resulting from the decomposition of lignocellulosic biomass during biofuel production. This study assessed the capacity of a microbial electrolysis cell (MEC) to produce hydrogen gas (H2) using a mixture of two furanic (furfural, FF; 5-hydroxymethyl furfural, HMF) and three phenolic (syringic acid, SA; vanillic acid, VA; and 4-hydroxybenzoic acid, HBA) compounds as the sole carbon and energy source in the bioanode. The rate and extent of biotransformation of the five compounds, efficiency of H2 production, as well as the anode microbial community structure were investigated. The five compounds were completelymore » transformed within 7-day batch runs and their biotransformation rate increased with increasing initial concentration. At an initial concentration of 1,200 mg/L (8.7 mM) of the mixture of the five compounds, their biotransformation rate ranged from 0.85 to 2.34 mM/d. The anode coulombic efficiency was 44-69%, which is comparable to wastewater-fed MECs. The H2 yield varied from 0.26 to 0.42 g H2-COD/g COD removed in the anode, and the bioanode volume-normalized H2 production rate was 0.07-0.1 L/L-d. The major identified fermentation products that did not transform further were catechol and phenol. Acetate was the direct substrate for exoelectrogenesis. Current and H2 production were inhibited at an initial substrate concentration of 1,200 mg/L, resulting in acetate accumulation at a much higher level than that measured in other batch runs conducted with a lower initial concentration of the five compounds. The anode microbial community consisted of exoelectrogens, putative degraders of the five compounds, and syntrophic partners of exoelectrogens. The H2 production route demonstrated in this study has proven to be an alternative to the currently used process of reforming natural gas to supply H2 needed to upgrade bio-oils to stable hydrocarbon fuels.« less

  13. Biotransformation of furanic and phenolic compounds with hydrogen gas production in a microbial electrolysis cell

    SciTech Connect

    Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

    2015-10-27

    In this study, furanic and phenolic compounds are problematic byproducts resulting from the decomposition of lignocellulosic biomass during biofuel production. This study assessed the capacity of a microbial electrolysis cell (MEC) to produce hydrogen gas (H2) using a mixture of two furanic (furfural, FF; 5-hydroxymethyl furfural, HMF) and three phenolic (syringic acid, SA; vanillic acid, VA; and 4-hydroxybenzoic acid, HBA) compounds as the sole carbon and energy source in the bioanode. The rate and extent of biotransformation of the five compounds, efficiency of H2 production, as well as the anode microbial community structure were investigated. The five compounds were completely transformed within 7-day batch runs and their biotransformation rate increased with increasing initial concentration. At an initial concentration of 1,200 mg/L (8.7 mM) of the mixture of the five compounds, their biotransformation rate ranged from 0.85 to 2.34 mM/d. The anode coulombic efficiency was 44-69%, which is comparable to wastewater-fed MECs. The H2 yield varied from 0.26 to 0.42 g H2-COD/g COD removed in the anode, and the bioanode volume-normalized H2 production rate was 0.07-0.1 L/L-d. The major identified fermentation products that did not transform further were catechol and phenol. Acetate was the direct substrate for exoelectrogenesis. Current and H2 production were inhibited at an initial substrate concentration of 1,200 mg/L, resulting in acetate accumulation at a much higher level than that measured in other batch runs conducted with a lower initial concentration of the five compounds. The anode microbial community consisted of exoelectrogens, putative degraders of the five compounds, and syntrophic partners of exoelectrogens. The H2 production route demonstrated in this study has proven to be an alternative to the currently used process of reforming natural gas to supply H2 needed to

  14. A Novel Method for Analyzing Microbially Affiliated Volatile Organic Compounds in Soil Environments

    NASA Astrophysics Data System (ADS)

    Ruhs, C. V.; McNeal, K. S.

    2010-12-01

    A concerted, international effort by citizens, governments, industries and educational systems is necessary to address the myriad environmental issues that face us today. The authors of this paper concentrate on soil environments and, specifically, the methods currently used to characterize them. The ability to efficiently and effectively monitor and characterize various soils is desired, allows for the study, supervision, and protection of natural and cultivated ecosystems, and may assist stakeholders in meeting governmentally-imposed environmental standards. This research addresses soil characterization by a comparison of four methods that emphasize a combination of microbial community and metabolic measures: BIOLOG, fatty acid methyl-ester analysis (FAME), descriptive physical and chemical analysis (moisture content, pH, carbon content, nutrient content, and grain size), and the novel soil-microbe volatile organic compound analysis (SMVOC) presented in this work. In order to achieve the method comparison, soils were collected from three climatic regions (Bahamas, Michigan, and Mississippi), with three samples taken from niche ecosystems found at each climatic region (a total of nine sites). Of interest to the authors is whether or not an investigation of microbial communities and the volatile organic compounds (VOCs) produced by microbial communities from nine separate soil ecosystems provides useful information about soil dynamics. In essence, is analysis of soil-derived VOCs using gas chromatography-mass spectrometry (GC-MS) an effective method for characterizing microbial communities and their metabolic activity of soils rapidly and accurately compared with the other three traditional characterization methods? Preliminary results suggest that VOCs in each of these locales differ with changes in soil types, soil moisture, and bacterial community. Each niche site shows distinct patterns in both VOCs and BIOLOG readings. Results will be presented to show the

  15. Inhibitory Effect of Furanic and Phenolic Compounds on Exoelectrogenesis in a Microbial Electrolysis Cell Bioanode

    DOE PAGES

    Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

    2016-09-09

    Furanic and phenolic compounds are 20 lignocellulose-derived compounds known to inhibit to H2- and ethanol- producing microorganisms in dark fermentation. Bioelectrochemical conversion of furanic and phenolic compounds to electricity or H2 has recently been demonstrated as a productive method to use these compounds. However, potential inhibitory effect of furanic and phenolic compounds on exoelectrogenesis in bioelectrochemical systems is not well understood. This study systematically investigated the inhibitory effect of furfural (FF), 5-hydroxymethylfurfural (HMF), syringic acid (SA), vanillic acid (VA), and 4-hydroxybenzoic acid (HBA) on exoelectrogenesis in the bioanode of a microbial electrolysis cell. A mixture of these five compounds atmore » an increasing initial total concentration from 0.8 to 8.0 g/L resulted in current decrease up to 91%. The observed inhibition primarily affected exoelectrogenesis, instead of non-exoelectrogenic biotransformation pathways (e.g., fermentation) of the five compounds. Furthermore, the parent compounds at a high concentration, as opposed to their biotransformation products, were responsible for the observed inhibition. Tests with individual compounds show that all five parent compounds contributed to the observed inhibition by the mixture. The IC50 (concentration resulting in 50% current decrease) was estimated as 2.7 g/L for FF, 3.0 g/L for HMF, 1.9 g/L for SA, 2.1 g/L for VA and 2.0 g/L for HBA. Nevertheless, these compounds below their non-inhibitory concentrations jointly resulted in significant inhibition as a mixture. Catechol and phenol, which were persistent biotransformation products of the mixture, inhibited exoelectrogens at high concentrations, but to a lesser extent than the parent compounds. Recovery of exoelectrogenesis from inhibition by all compounds was observed, except for catechol, which resulted in irreversible inhibition. The reversibility of inhibition, as well as the observed difference in recovery

  16. Biological technologies for the removal of sulfur containing compounds from waste streams: bioreactors and microbial characteristics.

    PubMed

    Li, Lin; Zhang, Jingying; Lin, Jian; Liu, Junxin

    2015-10-01

    Waste gases containing sulfur compounds, such as hydrogen sulfide, sulfur dioxide, thioethers, and mercaptan, produced and emitted from industrial processes, wastewater treatment, and landfill waste may cause undesirable issues in adjacent areas and contribute to atmospheric pollution. Their control has been an area of concern and research for many years. As alternative to conventional physicochemical air pollution control technologies, biological treatment processes which can transform sulfur compounds to harmless products by microbial activity, have gained in popularity due to their efficiency, cost-effectiveness and environmental acceptability. This paper provides an overview of the current biological techniques used for the treatment of air streams contaminated with sulfur compounds as well as the advances made in the past year. The discussion focuses on bioreactor configuration and design, mechanism of operation, insights into the overall biological treatment process, and the characterization of the microbial species present in bioreactors, their populations and their interactions with the environment. Some bioreactor case studies are also introduced. Finally, the perspectives on future research and development needs in this research area were also highlighted.

  17. Microbial community response to addition of polylactate compounds to stimulate hexavalent chromium reduction in groundwater.

    PubMed

    Brodie, Eoin L; Joyner, Dominique C; Faybishenko, Boris; Conrad, Mark E; Rios-Velazquez, Carlos; Malave, Josue; Martinez, Ramon; Mork, Benjamin; Willett, Anna; Koenigsberg, Steven; Herman, Donald J; Firestone, Mary K; Hazen, Terry C

    2011-10-01

    To evaluate the efficacy of bioimmobilization of Cr(VI) in groundwater at the Department of Energy Hanford site, we conducted a series of microcosm experiments using a range of commercial electron donors with varying degrees of lactate polymerization (polylactate). These experiments were conducted using Hanford Formation sediments (coarse sand and gravel) immersed in Hanford groundwater, which were amended with Cr(VI) and several types of lactate-based electron donors (Hydrogen Release Compound, HRC; primer-HRC, pHRC; extended release HRC) and the polylactate-cysteine form (Metal Remediation Compound, MRC). The results showed that polylactate compounds stimulated an increase in bacterial biomass and activity to a greater extent than sodium lactate when applied at equivalent carbon concentrations. At the same time, concentrations of headspace hydrogen and methane increased and correlated with changes in the microbial community structure. Enrichment of Pseudomonas spp. occurred with all lactate additions, and enrichment of sulfate-reducing Desulfosporosinus spp. occurred with almost complete sulfate reduction. The results of these experiments demonstrate that amendment with the pHRC and MRC forms result in effective removal of Cr(VI) from solution most likely by both direct (enzymatic) and indirect (microbially generated reductant) mechanisms.

  18. Non-cytocidal infection of keratinocytes by canine distemper virus in the so-called hard pad disease of canine distemper.

    PubMed

    Gröne, A; Groeters, S; Koutinas, A; Saridomichelakis, M; Baumgärtner, W

    2003-10-17

    A late, but not uncommon sequel to canine distemper virus (CDV) infection of dogs is thickening of footpads and nasal planum, the so-called hard pad disease, originally described as vacuolar degeneration of epidermal keratinocytes with inclusion body formation and massive hyperkeratosis. However, in a recent study of footpads of naturally CDV-infected dogs only hyperkeratosis was observed without any of the other changes. Instead, acanthosis was frequently noticed. CDV nucleoprotein was present in the suprabasal keratinocytes and eccrine epithelial glands only. No CDV nucleoprotein was present in basal keratinocytes. This observation in combination with lack of obvious cytocidal changes strongly suggested the possibility of a restricted viral infection with presence of viral mRNA but without protein expression. Therefore, the presence of CDV nucleoprotein mRNA was investigated using in situ hybridization and compared to the localization of the nucleoprotein in footpads of clinically healthy and distemper dogs. Viral nucleoprotein and nucleoprotein mRNA in nearly all cases co-localized to the same compartments and basal keratinocytes did not contain nucleoprotein mRNA. These findings dispute the idea of a restricted viral infection of footpad keratinocytes in dogs with natural CDV infection. Instead, a migration of the virus to the epidermal surface along with the proliferating and differentiating epithelium is the most likely explanation for the lack of virus antigen in basal keratinocytes.

  19. Microbial use of gas phase organic compounds in the surface ocean

    NASA Astrophysics Data System (ADS)

    Arrieta, Jesus M.; Duarte, Carlos M.; Monserrat Sala, M.; Dachs, Jordi

    2016-04-01

    Large diffusive air-sea fluxes of gas-phase organic carbon (GOC) have been identified, indicating that the ocean may be a major sink for these compounds. However, little is known about the fate of these GOC compounds entering the surface ocean. We report efficient use of atmospheric GOC by marine prokaryotes at different locations in the NE Subtropical Atlantic Ocean, the Arctic Ocean and the Mediterranean Sea. Our results indicate that between 2 to 27% of the prokaryotic carbon demand was supported by GOC. Between 1 and 94% of the GOC entering the ocean was consumed by prokaryotes depending on locations, thus sustaining a disequilibrium, which drives the transfer of GOC from the atmosphere into the ocean. The magnitude of this, previously unnoticed, microbial GOC utilization stresses the need for incorporating the oceanic uptake of gaseous organic carbon into the global carbon budget.

  20. Remote sensing of microbial volatile organic compounds with a bioluminescent bioreporter integrated circuit

    NASA Astrophysics Data System (ADS)

    Ripp, Steven A.; Daumer, Kathleen A.; Garland, Jay L.; Simpson, Michael L.; Sayler, Gary S.

    2004-03-01

    As a means towards advanced, early-warning detection of microbial growth in enclosed structures, we have constructed a bioluminescent bioreporter for the detection of the microbial volatile organic compound (MVOC) p-cymene. MVOCs are produced as metabolic by-products of bacteria and fungi and are detectable before any visible signs of microbial growth appear, thereby serving as very early indicators of potential biocontamination problems. The bioreporter, designated Pseudomonas putida UT93, contains a Vibrio fischeri luxCDABE gene fusion to a p-cymene/p-cumate inducible promoter. Exposure of strain UT93 to p-cymene from approximately 0.02 to 850 ppm produced self-generated bioluminescence in less than 1.5 hours. The bioreporter was also interfaced with an integrated circuit microluminometer to create a miniaturized hybrid sensor for remote monitoring of p-cymene signatures. This bioluminescent bioreporter integrated circuit (BBIC) device was capable of detecting fungal presence within approximately 3.5 hours of initial exposure to Penicillium roqueforti.

  1. Subclass distribution of IgG antibodies to the rat oesophagus stratum corneum (so-called anti-keratin antibodies) in rheumatoid arthritis.

    PubMed Central

    Vincent, C; Serre, G; Basile, J P; Lestra, H C; Girbal, E; Sebbag, M; Soleilhavoup, J P

    1990-01-01

    Serum IgG, labelling the stratum corneum of the rat oesophagus epithelium, so-called anti-keratin antibodies (AKA) constitute the most specific marker for the diagnosis of rheumatoid arthritis. In this study, we investigated 31 IgG AKA-positive rheumatoid sera and 21 control sera from patients with non-rheumatoid inflammatory rheumatic diseases. The serum level of IgG1,2,3 and 4 was determined by radial immunodiffusion and the subclass distribution of IgG AKA by a three-step semi-quantitative immunofluorescence assay using standard monoclonal antibodies specific for each of the four human IgG subclasses. In the rheumatoid sera, the serum level of IgG1 was found to be significantly increased and the level of IgG2 significantly decreased with regard to the control sera, while the levels of IgG3 and 4 as well as total IgG were in the normal range. IgG1,2,3, and 4 AKA were detected in 27 (87%), 6 (19%), 4 (13%) and 11 (35%) of the 31 rheumatoid sera, respectively, and were found to be independent of the clinical and biological indices of the disease. In spite of inter-individual heterogeneity, two predominant profiles were distinguished: IgG1 (alone) and IgG(1 + 4), which together represented 18 sera (58%). The large predominance of IgG1 AKA and the quasi-absence of IgG2 AKA suggest that the recognized antigen may be partly comprised of protein. Moreover, the high frequency of occurrence of IgG4 AKA might result from chronic exposure to the eliciting antigen, which could be a genuine autoantigen since we demonstrated that it is also present in the stratum corneum of human epidermis. Images Fig. 1 PMID:1696185

  2. Volatile organic compound production and consumption by microbial plankton communities on the NOAA WACS cruise

    NASA Astrophysics Data System (ADS)

    Giovannoni, S. J.; Halsey, K.; Thrash, J. C.; De Gouw, J. A.; Graus, M.

    2013-12-01

    Information about biological sources and sinks of volatile organic compounds (VOCs) in the ocean surface could result in a better understanding of the underlying causes of variation in air/sea VOC fluxes, and potentially could alter predictions about the impact of climate change on ocean surface ecology and air/sea interactions. The goal of this work was to measure rates of biological production, oxidation and assimilation of volatile organic compounds (VOCs) by microbial plankton communities along the WACS cruise transect from Boston to Bermuda in August 2013. Tangential flow filtration was used to concentrate microbial plankton communities for incubation in environmentally controlled dynamic stripping chambers under simulated ocean surface layer conditions. Gas streams exiting the chambers were monitored in real time with proton transfer reaction mass spectrometry (PTR-MS). In separate experiments aliquots of plankton suspensions were incubated with 14C-methanol, 14C-TMAO, and 14C-pyruvate, and the assimilation of 14C into biomass and the production of 14C-CO2 were measured. Results showed that the highly productive George's Bank plankton community has a high capacity for methanol and trimethylamine oxide (TMAO) oxidation. Biomass was estimated by counting cells. The rate of incorporation of methanol-carbon into biomass was only 21% of the rate of methanol oxidation to CO2. Similar results were observed for TMAO. These experiments also allowed estimates of kinetic constants for both compounds. The half-saturation constants (Ks) for methanol oxidation were similar in natural populations collected at George's Bank and the Sargasso Sea (12.8 and 9.9 μM, respectively). Interestingly, the Ks values for TMAO oxidation were an order of magnitude lower than for methanol in plankton communities sampled from both sites (0.5 and 0.3 μM, respectively). These results provide additional evidence that microbial plankton have a high capacity for oxidation of these low

  3. Microbial turnover and incorporation of organic compounds in oil sand mining reclamation sites

    NASA Astrophysics Data System (ADS)

    Lappé, M.; Kallmeyer, J.

    2013-12-01

    Microorganisms play an important role in the development of new soils and in the reclamation of disturbed landscapes. Especially in hydrocarbon-contaminated soils their ability to degrade organic matter and pollutants makes them essential to re-establish full ecosystem functionality. Microbes are also involved in the mobilization of nutrients for plant growth and in the production of greenhouse gases. Reclamation sites from oil sand mining activities in Alberta, Canada, contain residual bitumen as well as other hydrocarbons. So, these areas provide a great opportunity to study microbial degradation of residual contaminants from oil sand. To get an impression of degradation rates as well as metabolic pathways, incubation experiments were performed in the lab. We measured microbial turnover (catabolic metabolism) and incorporation (anabolic metabolism) rates of different common organic compounds in samples from differently treated reclamation sites - with plant cover and without plant cover. About 10 g of sample material was suspended in 10 mL of a solution that mimics the in-situ concentration of dissolved ions. Radioactively labelled 14C-acetate was added as a common substrate, whereas 14C-naphthenic acid was chosen to investigate the microbial community's capability to utilize a typical hydrocarbon pollutant in oil sand tailings as a nutrient source. To test for the influence of fertilizers on microbial activity, phosphate, nitrate and potassium were added to some samples in different combinations. Incubations were run over two different time periods (7 and 14 days). At the end of each incubation experiment, the amount of produced 14CO2, 14C incorporated into the cells and the remaining unreacted 14C in the slurry were measured. First results show that most of the added 14C-acetate is used for respiration as it is mostly released as 14CO2. In upper soil layers only about 3% of 14C is incorporated into cells, whereas in deeper horizons with lower cell abundances

  4. Characteristics of microbial volatile organic compound flux rates from soil and plant litter

    NASA Astrophysics Data System (ADS)

    Gray, C. M.; Fierer, N.

    2013-12-01

    Our knowledge of microbial production and consumption of volatile organic compounds (VOCs) from soil and litter, as well as which microorganisms are involved, is relatively limited compared to what we know about VOC emissions from terrestrial plants. With climate change expecting to alter plant community composition, nitrogen (N) deposition rates, mean annual temperatures, precipitation patterns, and atmospheric VOC concentrations, it is unknown how microbial production and consumption of VOCs from litter and soil will respond. We have spent the last 5 years quantifying VOC flux rates in decaying plant litter, mineral soils and from a subalpine field site using a proton transfer reaction mass spectrometer (PTR-MS). Microbial production, relative to abiotic sources, accounted for 78% to 99% of the total VOC emissions from decomposing litter, highlighting the importance of microbial metabolisms in these systems. Litter chemistry correlated with the types of VOCs emitted, of which, methanol was emitted at the highest rates from all studies. The net emissions of carbon as VOCs was found to be up to 88% of that emitted as CO2 suggesting that VOCs likely represent an important component of the carbon cycle in many terrestrial systems. Nitrogen additions drastically reduced VOC emissions from litter to near zero, though it is still not understood whether this was due to an increase in consumption or a decrease in production. In the field, the root system contributed to 53% of the carbon that was emitted as VOCs from the soil with increasing air temperatures correlating to an increase in VOC flux rates from the soil system. Finally, we are currently utilizing next generation sequencing techniques (Illumina MiSeq) along with varying concentrations of isoprene, the third most abundant VOC in the atmosphere behind methane and methanol, above soils in a laboratory incubation to determine consumption rates and the microorganisms (bacteria, archaea and fungi) associated with the

  5. Development of a novel compound microbial agent for degradation of kitchen waste.

    PubMed

    Zhao, Kaining; Xu, Rui; Zhang, Ying; Tang, Hao; Zhou, Chuanbin; Cao, Aixin; Zhao, Guozhu; Guo, Hui

    2017-02-21

    Large quantities of kitchen waste are produced in modern society and its disposal poses serious environmental and social problems. The aim of this study was to isolate degradative strains from kitchen waste and to develop a novel and effective microbial agent. One hundred and four strains were isolated from kitchen waste and the 84 dominant strains were used to inoculate protein-, starch-, fat- and cellulose-containing media for detecting their degradability. Twelve dominant strains of various species with high degradability (eight bacteria, one actinomycetes and three fungi) were selected to develop a compound microbial agent "YH" and five strains of these species including H7 (Brevibacterium epidermidis), A3 (Paenibacillus polymyxa), E3 (Aspergillus japonicus), F9 (Aspergillus versicolor) and A5 (Penicillium digitatum), were new for kitchen waste degradation. YH was compared with three commercial microbial agents-"Tiangeng" (TG), "Yilezai" (YLZ) and Effective Microorganisms (EM), by their effects on reduction, maturity and deodorization. The results showed that YH exerted the greatest efficacy on mass loss which decreased about 65.87% after 14 days. The agent inhibited NH3 and H2S emissions significantly during composting process. The concentration of NH3 decreased from 7.1 to 3.2ppm and that of H2S reduced from 0.7 to 0.2ppm. Moreover, E4/E6 (Extinction value460nm/Extinction value665nm) of YH decreased from 2.51 to 1.31, which meant YH had an obvious maturity effect. These results highlighted the potential application of YH in composting kitchen waste.

  6. Use of natural compounds to improve the microbial stability of Amaranth-based homemade fresh pasta.

    PubMed

    Del Nobile, M A; Di Benedetto, N; Suriano, N; Conte, A; Lamacchia, C; Corbo, M R; Sinigaglia, M

    2009-04-01

    A study on the use of natural antimicrobial compounds to improve the microbiological stability of refrigerated amaranth-based homemade fresh pasta is presented in this work. In particular, the antimicrobial activity of thymol, lemon extract, chitosan and grapefruit seed extract (GFSE) has been tested against mesophilic and psychrotrophic bacteria, total coliforms, Staphylococcus spp., yeasts and moulds. A sensory analysis on both fresh and cooked pasta was also run. Results suggest that chitosan and GFSE strongly increase the microbial acceptability limit of the investigated spoilage microorganisms, being the former the most effective. Thymol efficiently reduces the growth of mesophilic bacteria, psychrotrophic bacteria and Staphylococcus spp., whereas it does not affect, substantially, the growth cycle of total coliforms. Lemon extract is the less effective in preventing microbial growth. In fact, it is able to delay only total mesophilic and psychrotrophic bacterial evolution. From a sensorial point of view no significant differences were recorded between the control samples and all the types of loaded amaranth-based pasta.

  7. Methylated sulfur compounds in microbial mats: In situ concentrations and metabolism by a colorless sulfur bacterium

    SciTech Connect

    Visscher, P.T. Netherlands Inst. for Sea Research, Den Burg ); Quist, P.; vanGemerden, H. )

    1991-06-01

    The concentrations of the volatile organic sulfur compounds methanethiol, dimethyl disulfide, and dimethyl sulfide (DMS) and the viable population capable of DMS utilization in laminated microbial ecosystems were evaluated. Significant levels of DMS and dimethyl disulfide (maximum concentrations of 220 and 24 nmol cm{sup 3} of sediment{sup {minus}1}, respectively) could be detected only at the top 20 mm of the microbial mat, whereas methanethiol was found only at depth horizons from 20 to 50 mm (maximum concentrations of 42 nmol cm{sup 3} of sediment{sup {minus}1}). DMS concentrations in the surface layer doubled after cold hydrolysis of its precursor, dimethylsulfoniopropioinate. Most-probable-number counts revealed 2.2 {times} 10{sup 5} cells cm{sup 3} of sediment{sup {minus}1}, in the 0- to 5-mm depth horizon, capable of growth on DMS as the sole source of energy. An obligately chemolithoautotrophic bacillus designated strain T5 was isolated from the top layer of the marine sediment. Continuous culture studies in which DMS was the growth-limiting substrate revealed a maximum specific growth rate of 0.10 h{sup {minus}1} and a saturation constant of 90 {mu}mol liter{sup {minus}1} for aerobic growth on this substrate.

  8. Screening of Microbial Extracts for Anticancer Compounds Using Streptomyces Kinase Inhibitor Assay.

    PubMed

    Shanbhag, Prashant; Bhave, Sarita; Vartak, Ashwini; Kulkarni-Almeida, Asha; Mahajan, Girish; Villanueva, Ivan; Davies, Julian

    2015-07-01

    Eukaryotic kinases are known to play an important role in signal transduction pathways by phosphorylating their respective substrates. Abnormal phosphorylations by these kinases have resulted in diseases. Hence inhibitors of kinases are of considerable pharmaceutical interest for a wide variety of disease targets, especially cancers. A number of reports have been published which indicate that eukaryotic-like kinases may complement two-component kinase systems in several bacteria. In Streptomyces sp. such kinases have been found to have a role in formation of aerial hyphae, spores, pigmentation & even in antibiotic production in some strains. Eukaryotic kinase inhibitors are seen to inhibit formation of aerial mycelia in Streptomyces without inhibiting vegetative mycelia. This property has been used to design an assay to screen for eukaryotic kinase inhibitors. The assay involves testing of compounds against Streptomyces 85E ATCC 55824 using agar well diffusion method. Inhibitors of kinases give rise to "bald" colonies where aerial mycelia and sporulation inhibition is seen. The assay has been standardized using known eukaryotic protein kinase inhibiting anticancer agents like AG-490, AG-1295, AG-1478, Flavopiridol and Imatinib as positive controls, at a concentration ranging from 10 μg/well to 100 μg/well. Anti-infective compounds which are not reported to inhibit eukaryotic protein kinases were used as negative controls. A number of microbial cultures have been screened for novel eukaryotic protein kinase inhibitors. Further these microbial extracts were tested in various cancer cell lines like Panel, HCT116, Calul, ACHN and H460 at a concentration of 10 μg/mL/ well. The anticancer data was seen correlating well with the Streptomyces kinase assay thus validating the assay.

  9. Weakening of salmonella with selected microbial metabolites of berry-derived phenolic compounds and organic acids.

    PubMed

    Alakomi, Hanna-Leena; Puupponen-Pimiä, Riitta; Aura, Anna-Marja; Helander, Ilkka M; Nohynek, Liisa; Oksman-Caldentey, Kirsi-Marja; Saarela, Maria

    2007-05-16

    Gram-negative bacteria are important food spoilage and pathogenic bacteria. Their unique outer membrane (OM) provides them with a hydrophilic surface structure, which makes them inherently resistant to many antimicrobial agents, thus hindering their control. However, with permeabilizers, compounds that disintegrate and weaken the OM, Gram-negative cells can be sensitized to several external agents. Although antimicrobial activity of plant-derived phenolic compounds has been widely reported, their mechanisms of action have not yet been well demonstrated. The aim of our study was to elucidate the role of selected colonic microbial metabolites of berry-derived phenolic compounds in the weakening of the Gram-negative OM. The effect of the agents on the OM permeability of Salmonella was studied utilizing a fluorescence probe uptake assay, sensitization to hydrophobic antibiotics, and lipopolysaccharide (LPS) release. Our results show that 3,4-dihydroxyphenylacetic acid, 3-hydroxyphenylacetic acid, 3-(3,4-dihydroxyphenyl)propionic acid (3,4-diHPP), 3-(4-hydroxyphenyl)propionic acid, 3-phenylpropionic acid, and 3-(3-hydroxyphenyl)propionic acid efficiently destabilized the OM of Salmonella enterica subsp. enterica serovar Typhimurium and S. enterica subsp. enterica serovar Infantis as indicated by an increase in the uptake of the fluorescent probe 1-N-phenylnaphthylamine (NPN). The OM-destabilizing activity of the compounds was partially abolished by MgCl2 addition, indicating that part of their activity is based on removal of OM-stabilizing divalent cations. Furthermore, 3,4-dihydroxyphenylacetic acid, 3-hydroxyphenylacetic acid, and 3,4-diHPP increased the susceptibility of S. enterica subsp. enterica serovar Typhimurium strains for novobiocin. In addition, organic acids present in berries, such as malic acid, sorbic acid, and benzoic acid, were shown to be efficient permeabilizers of Salmonella as shown by an increase in the NPN uptake assay and by LPS release.

  10. Production of a High Efficiency Microbial Flocculant by Proteus mirabilis TJ-1 Using Compound Organic Wastewater

    NASA Astrophysics Data System (ADS)

    Zhang, Zhiqiang; Xia, Siqing; Zhang, Jiao

    2010-11-01

    The production of a high efficiency microbial flocculant (MBF) by Proteus mirabilis TJ-1 using compound organic wastewater was investigated. To cut down the cost of the MBF production, several nutritive organic wastewaters were selected to replace glucose and peptone as the carbon source and the nitrogen source in the optimized medium of strain TJ-1, respectively. The compound wastewater of the milk candy and the soybean milk was found to be good carbon source and nitrogen source for this strain to produce MBF. The cost-effective culture medium consists of (per liter): 800 mL wastewater of milk candy, 200 mL wastewater of soybean milk, 0.3 g MgSO4ṡ7 H2O, 5 g K2HPO4, 2 g and KH2PO4, pH 7.0. The economic cost for the MBF production can be cut down over a half by using the developed culture medium. Furthermore, the utilization of the two wastewaters in the preparation of culture medium of strain TJ-1 can not only save their big treatment cost, but also realize their resource reuse.

  11. Metabolic and Microbial Modulation of the Large Intestine Ecosystem by Non-Absorbed Diet Phenolic Compounds: A Review.

    PubMed

    Mosele, Juana I; Macià, Alba; Motilva, Maria-José

    2015-09-18

    Phenolic compounds represent a diverse group of phytochemicals whose intake is associated with a wide spectrum of health benefits. As consequence of their low bioavailability, most of them reach the large intestine where, mediated by the action of local microbiota, a series of related microbial metabolites are accumulated. In the present review, gut microbial transformations of non-absorbed phenolic compounds are summarized. Several studies have reached a general consensus that unbalanced diets are associated with undesirable changes in gut metabolism that could be detrimental to intestinal health. In terms of explaining the possible effects of non-absorbed phenolic compounds, we have also gathered information regarded their influence on the local metabolism. For this purpose, a number of issues are discussed. Firstly, we consider the possible implications of phenolic compounds in the metabolism of colonic products, such as short chain fatty acids (SCFA), sterols (cholesterol and bile acids), and microbial products of non-absorbed proteins. Due to their being recognized as affective antioxidant and anti-inflammatory agents, the ability of phenolic compounds to counteract or suppress pro-oxidant and/or pro-inflammatory responses, triggered by bowel diseases, is also presented. The modulation of gut microbiota through dietetic maneuvers including phenolic compounds is also commented on. Although the available data seems to assume positive effects in terms of gut health protection, it is still insufficient for solid conclusions to be extracted, basically due to the lack of human trials to confirm the results obtained by the in vitro and animal studies. We consider that more emphasis should be focused on the study of phenolic compounds, particularly in their microbial metabolites, and their power to influence different aspects of gut health.

  12. Microbial trench-based optofluidic system for reagentless determination of phenolic compounds.

    PubMed

    Sanahuja, David; Giménez-Gómez, Pablo; Vigués, Núria; Ackermann, Tobias Nils; Guerrero-Navarro, Alfons Eduard; Pujol-Vila, Ferran; Sacristán, Jordi; Santamaria, Nidia; Sánchez-Contreras, María; Díaz-González, María; Mas, Jordi; Muñoz-Berbel, Xavier

    2015-04-07

    Phenolic compounds are one of the main contaminants of soil and water due to their toxicity and persistence in the natural environment. Their presence is commonly determined with bulky and expensive instrumentation (e.g. chromatography systems), requiring sample collection and transport to the laboratory. Sample transport delays data acquisition, postponing potential actions to prevent environmental catastrophes. This article presents a portable, miniaturized, robust and low-cost microbial trench-based optofluidic system for reagentless determination of phenols in water. The optofluidic system is composed of a poly(methyl methacrylate) structure, incorporating polymeric optical elements and miniaturized discrete auxiliary components for optical transduction. An electronic circuit, adapted from a lock-in amplifier, is used for system control and interfering ambient light subtraction. In the trench, genetically modified bacteria are stably entrapped in an alginate hydrogel for quantitative determination of model phenol catechol. Alginate is also acting as a diffusion barrier for compounds present in the sample. Additionally, the superior refractive index of the gel (compared to water) confines the light in the lower level of the chip. Hence, the optical readout of the device is only altered by changes in the trench. Catechol molecules (colorless) in the sample diffuse through the alginate matrix and reach bacteria, which degrade them to a colored compound. The absorbance increase at 450 nm reports the presence of catechol simply, quickly (~10 min) and quantitatively without addition of chemical reagents. This miniaturized, portable and robust optofluidic system opens the possibility for quick and reliable determination of environmental contamination in situ, thus mitigating the effects of accidental spills.

  13. Species-specific production of microbial volatile organic compounds (MVOC) by airborne fungi from a compost facility.

    PubMed

    Fischer, G; Schwalbe, R; Möller, M; Ostrowski, R; Dott, W

    1999-08-01

    Thirteen airborne fungal species frequently isolated in composting plants were screened for microbial volatile organic compounds (MVOC), i.e., Aspergillus candidus, A. fumigatus, A. versicolor, Emericella nidulans, Paecilomyces variotii, Penicillium brevicompactum, Penicillium clavigerum, Penicillium crustosum, Penicillium cyclopium, Penicillium expansum, Penicillium glabrum, Penicillium verruculosum, and Tritirachium oryzae. Air samples from pure cultures were sorbed on Tenax GR and analyzed by thermal desorption in combination with GC/MS. Various hydrocarbons of different chemical groups and a large number of terpenes were identified. Some compounds such as 3-methyl-1-butanol and 1-octen-3-ol were produced by a number of species, whereas some volatiles were specific for single species. An inventory of microbial metabolites will allow identification of potential health hazards due to an exposure to fungal propagules and metabolites in the workplace. Moreover, species-specific volatiles may serve as marker compounds for the selective detection of fungal species in indoor domestic and working environments.

  14. Physico-chemical parameters, bioactive compounds and microbial quality of thermo-sonicated carrot juice during storage.

    PubMed

    Martínez-Flores, Héctor E; Garnica-Romo, Ma Guadalupe; Bermúdez-Aguirre, Daniela; Pokhrel, Prashant Raj; Barbosa-Cánovas, Gustavo V

    2015-04-01

    Thermosonication has been successfully tested in food for microbial inactivation; however, changes in bioactive compounds and shelf-life of treated products have not been thoroughly investigated. Carrot juice was thermo-sonicated (24 kHz, 120 μm amplitude) at 50 °C, 54 °C and 58 °C for 10 min (acoustic power 2204.40, 2155.72, 2181.68 mW/mL, respectively). Quality parameters and microbial growth were evaluated after processing and during storage at 4 °C. Control and sonicated treatments at 50 °C and 54 °C had 10, 12 and 14 d of shelf-life, respectively. Samples sonicated at 58 °C had the best quality; microbial growth remained low at around 3-log for mesophiles, 4.5-log for yeasts and molds and 2-log for enterobacteria after 20 d of storage. Furthermore, thermo-sonicated juice at 58 °C retained >98% of carotenoids and 100% of ascorbic acid. Phenolic compounds increased in all stored, treated juices. Thermo-sonication is therefore a promising technology for preserving the quality of carrot juice by minimising the physicochemical changes during storage, retarding microbial growth and retaining the bioactive compounds.

  15. Preliminary assessment of a model to predict mold contamination based on microbial volatile organic compound profiles.

    PubMed

    LeBouf, Ryan F; Schuckers, Stephanie A; Rossner, Alan

    2010-08-01

    Identification of mold growth based on microbial volatile organic compounds (MVOCs) may be a viable alternative to current bioaerosol assessment methodologies. A feed-forward back propagation (FFBP) artificial neural network (ANN) was developed to correlate MVOCs with bioaerosol levels in built environments. A cross-validation MATLAB script was developed to train the ANN and produce model results. Entech Bottle-Vacs were used to collect chemical grab samples at 10 locations in northern NY during 17 sampling periods from July 2006 to August 2007. Bioaerosol samples were collected concurrently with chemical samples. An Anderson N6 impactor was used in conjunction with malt extract agar and dichloran glycerol 18 to collect viable mold samples. Non-viable samples were collected with Air-O-Cell cassettes. Chemical samples and bioaerosol samples were used as model inputs and model targets, respectively. Previous researchers have suggested the use of MVOCs as indicators of mold growth without the use of a pattern recognition program limiting their success. The current proposed strategy implements a pattern recognition program making it instrumental for field applications. This paper demonstrates that FFBP ANN may be used in conjunction with chemical sampling in built environments to predict the presence of mold growth.

  16. Microbial Communities and Bioactive Compounds in Marine Sponges of the Family Irciniidae—A Review

    PubMed Central

    Hardoim, Cristiane C. P.; Costa, Rodrigo

    2014-01-01

    Marine sponges harbour complex microbial communities of ecological and biotechnological importance. Here, we propose the application of the widespread sponge family Irciniidae as an appropriate model in microbiology and biochemistry research. Half a gram of one Irciniidae specimen hosts hundreds of bacterial species—the vast majority of which are difficult to cultivate—and dozens of fungal and archaeal species. The structure of these symbiont assemblages is shaped by the sponge host and is highly stable over space and time. Two types of quorum-sensing molecules have been detected in these animals, hinting at microbe-microbe and host-microbe signalling being important processes governing the dynamics of the Irciniidae holobiont. Irciniids are vulnerable to disease outbreaks, and concerns have emerged about their conservation in a changing climate. They are nevertheless amenable to mariculture and laboratory maintenance, being attractive targets for metabolite harvesting and experimental biology endeavours. Several bioactive terpenoids and polyketides have been retrieved from Irciniidae sponges, but the actual producer (host or symbiont) of these compounds has rarely been clarified. To tackle this, and further pertinent questions concerning the functioning, resilience and physiology of these organisms, truly multi-layered approaches integrating cutting-edge microbiology, biochemistry, genetics and zoology research are needed. PMID:25272328

  17. Analysis of organic compounds' degradation and electricity generation in anaerobic fluidized bed microbial fuel cell for coking wastewater treatment.

    PubMed

    Liu, Xinmin; Wu, Jianjun; Guo, Qingjie

    2017-02-22

    A single-chambered packing-type anaerobic fluidized microbial fuel cell (AFBMFC) with coking wastewater (CWW) as fuel was built to treat CWW, which not only has high treating efficiency, but also can convert organic matter in wastewater into electricity. AFBMFC was constructed by using anaerobic sludge that was domesticated as inoculation sludge, which was used to biochemically treat CWW. The organic compounds in CWW were extracted by liquid-liquid extraction step by step every day. The extraction phase was concentrated by a rotary evaporator and a nitrogen sweeping device and was analyzed by GC-MS. And the electricity-generation performances of AFBMFC were investigated. The results show that the composition of CWW was complicated, which mainly contains hydrocarbons, phenols, nitrogenous organic compounds, alcohols and aldehydes, esters and acids and so on. After a cycle of anaerobic biochemical treatment, the content of organic compounds in the effluent decreased significantly. After the treatment of AFBMFC, 99.9% phenols, 98.4% alcohol and aldehydes and 95.3% nitrogenous compounds were biodegraded. In the effluent, some new compounds (such as tricosane and dibutyl phthalate) were produced. The chemical oxygen demand (COD) of CWW decreased from 3372 to 559 mg/L in the closed-circuit microbial fuel cell, and the COD removal was 83.4 ± 1.0%. The maximum power density of AFBMFC was 2.13 ± 0.01 mW m(-2).

  18. MICROBIAL DEGRADATION OF NITROGEN, OXYGEN AND SULFUR HETEROCYCLIC COMPOUNDS UNDER ANAEROBIC CONDITIONS: STUDIES WITH AQUIFER SAMPLES

    EPA Science Inventory

    The potential for anaerobic biodegradation of 12 heterocyclic model compounds was studied. Nine of the model compounds were biotransformed in aquifer slurries under sulfate-reducing or methanogenic conditions. The nitrogen and oxygen heterocyclic compounds were more susceptible t...

  19. Pathological aspects of so called "hilar cholangiocarcinoma"

    PubMed Central

    Castellano-Megías, Víctor M; Ibarrola-de Andrés, Carolina; Colina-Ruizdelgado, Francisco

    2013-01-01

    Cholangiocarcinoma (CC) arising from the large intrahepatic bile ducts and extrahepatic hilar bile ducts share clinicopathological features and have been called hilar and perihilar CC as a group. However, “hilar and perihilar CC” are also used to refer exclusively to the intrahepatic hilar type CC or, more commonly, the extrahepatic hilar CC. Grossly, a major distinction can be made between papillary and non-papillary tumors. Histologically, most hilar CCs are well to moderately differentiated conventional type (biliary) carcinomas. Immunohistochemically, CK7, CK20, CEA and MUC1 are normally expressed, being MUC2 positive in less than 50% of cases. Two main premalignant lesions are known: biliary intraepithelial neoplasia (BilIN) and intraductal papillary neoplasm of the biliary tract (IPNB). IPNB includes the lesions previously named biliary papillomatosis and papillary carcinoma. A series of 29 resected hilar CC from our archives is reviewed. Most (82.8%) were conventional type adenocarcinomas, mostly well to moderately differentiated, although with a broad morphological spectrum; three cases exhibited a poorly differentiated cell component resembling signet ring cells. IPNB was observed in 5 (17.2%), four of them with an associated invasive carcinoma. A clear cell type carcinoma, an adenosquamous carcinoma and two gastric foveolar type carcinomas were observed. PMID:23919110

  20. [On the so-called "hysteroepilepsy"].

    PubMed

    Kistelska-Nielubowicz, H; Iwińska, B; Kazubska, M

    1979-01-01

    The authors examined on an outpatient basis 14 patients treated previously at the Neurological Department, Institute of Psychoneurology in Warsaw or at the Neurological Department of the Grochów Hospital in the years 1965--1972 in whom epilepsy had been diagnosed but who had also had hysterical seizures. Young women aged 20--30 years with temporal-lobe epilepsy prevailed in this group. In most of them hysterical seizures appeared within 5 years after the first epileptic seizure when the frequency of true seizures decreased. In more than half these patients it was possible to find a connection between the occurrence of hypsterical seizures and conflict situations. Psychiatric examination failed to find in most cases any symptoms of epileptic characteropathy, but mood disturbances of the type of depression with dysphoria were disclosed, other findings included immature personality, egocentrism and extraversion. Although the clinical material reviewed by the authors contained only a negligible proportion of cases, it may be possible that they are more numerous among outpatients and the correct diagnosis of these cases is particularly important for further treatment since anticonvulsants are insufficient and sociotherapy with psychotherapy are indicated.

  1. On So-called Test Bias

    ERIC Educational Resources Information Center

    McNemar, Quinn

    1975-01-01

    Noting that the practitioner is confronted with conflicting definitions of "fairness" that claim to avoid "bias" in test usage, this article asserts that "mean fairness" can be achieved by use of multiple regression with the dichotomous variate, group membership, included as a predictor; mean fairness also holds for sub-groupings, based on test…

  2. The Extent of Fermentative Transformation of Phenolic Compounds in the Bioanode Controls Exoelectrogenic Activity in a Microbial Electrolysis Cell

    DOE PAGES

    Zeng, Xiaofei; Collins, Maya; Borole, Abhijeet P.; ...

    2016-11-27

    Phenolic compounds in hydrolysate/pyrolysate and wastewater streams produced during the pretreatment of lignocellulosic biomass for biofuel production present a significant challenge in downstream processes. Bioelectrochemical systems are increasingly recognized as an alternative technology to handle biomass-derived streams and to promote water reuse in biofuel production. Thus, a thorough understanding of the fate of phenolic compounds in bioanodes is urgently needed. The present study investigated the biotransformation of three structurally similar phenolic compounds (syringic acid, SA; vanillic acid, VA; 4-hydroxybenzoic acid, HBA), and their individual contribution to exoelectrogenesis in a microbial electrolysis cell (MEC) bioanode. Fermentation of SA resulted in themore » highest exoelectrogenic activity among the three compounds tested, with 50% of the electron equivalents converted to current, compared to 12 and 9% for VA and HBA, respectively. The biotransformation of SA, VA and HBA was initiated by demethylation and decarboxylation reactions common to all three compounds, resulting in their corresponding hydroxylated analogs. SA was transformed to pyrogallol (1,2,3-trihydroxybenzene), whose aromatic ring was then cleaved via a phloroglucinol pathway, resulting in acetate production, which was then used in exoelectrogenesis. In contrast, more than 80% of VA and HBA was converted to catechol (1,2-dihydroxybenzene) and phenol (hydroxybenzene) as their respective dead-end products. The persistence of catechol and phenol is explained by the fact that the phloroglucinol pathway does not apply to di- or mono-hydroxylated benzenes. Previously reported, alternative ring-cleaving pathways were either absent in the bioanode microbial community or unfavorable due to high energy-demand reactions. With the exception of acetate oxidation, all biotransformation steps in the bioanode occurred via fermentation, independently of exoelectrogenesis. Therefore, the observed

  3. The extent of fermentative transformation of phenolic compounds in the bioanode controls exoelectrogenic activity in a microbial electrolysis cell.

    PubMed

    Zeng, Xiaofei; Collins, Maya A; Borole, Abhijeet P; Pavlostathis, Spyros G

    2017-02-01

    Phenolic compounds in hydrolysate/pyrolysate and wastewater streams produced during the pretreatment of lignocellulosic biomass for biofuel production present a significant challenge in downstream processes. Bioelectrochemical systems are increasingly recognized as an alternative technology to handle biomass-derived streams and to promote water reuse in biofuel production. Thus, a thorough understanding of the fate of phenolic compounds in bioanodes is urgently needed. The present study investigated the biotransformation of three structurally similar phenolic compounds (syringic acid, SA; vanillic acid, VA; 4-hydroxybenzoic acid, HBA), and their individual contribution to exoelectrogenesis in a microbial electrolysis cell (MEC) bioanode. Fermentation of SA resulted in the highest exoelectrogenic activity among the three compounds tested, with 50% of the electron equivalents converted to current, compared to 12 and 9% for VA and HBA, respectively. The biotransformation of SA, VA and HBA was initiated by demethylation and decarboxylation reactions common to all three compounds, resulting in their corresponding hydroxylated analogs. SA was transformed to pyrogallol (1,2,3-trihydroxybenzene), whose aromatic ring was then cleaved via a phloroglucinol pathway, resulting in acetate production, which was then used in exoelectrogenesis. In contrast, more than 80% of VA and HBA was converted to catechol (1,2-dihydroxybenzene) and phenol (hydroxybenzene) as their respective dead-end products. The persistence of catechol and phenol is explained by the fact that the phloroglucinol pathway does not apply to di- or mono-hydroxylated benzenes. Previously reported, alternative ring-cleaving pathways were either absent in the bioanode microbial community or unfavorable due to high energy-demand reactions. With the exception of acetate oxidation, all biotransformation steps in the bioanode occurred via fermentation, independently of exoelectrogenesis. Therefore, the observed

  4. The Extent of Fermentative Transformation of Phenolic Compounds in the Bioanode Controls Exoelectrogenic Activity in a Microbial Electrolysis Cell

    SciTech Connect

    Zeng, Xiaofei; Collins, Maya; Borole, Abhijeet P.; Pavlostathis, Spyros

    2016-11-27

    Phenolic compounds in hydrolysate/pyrolysate and wastewater streams produced during the pretreatment of lignocellulosic biomass for biofuel production present a significant challenge in downstream processes. Bioelectrochemical systems are increasingly recognized as an alternative technology to handle biomass-derived streams and to promote water reuse in biofuel production. Thus, a thorough understanding of the fate of phenolic compounds in bioanodes is urgently needed. The present study investigated the biotransformation of three structurally similar phenolic compounds (syringic acid, SA; vanillic acid, VA; 4-hydroxybenzoic acid, HBA), and their individual contribution to exoelectrogenesis in a microbial electrolysis cell (MEC) bioanode. Fermentation of SA resulted in the highest exoelectrogenic activity among the three compounds tested, with 50% of the electron equivalents converted to current, compared to 12 and 9% for VA and HBA, respectively. The biotransformation of SA, VA and HBA was initiated by demethylation and decarboxylation reactions common to all three compounds, resulting in their corresponding hydroxylated analogs. SA was transformed to pyrogallol (1,2,3-trihydroxybenzene), whose aromatic ring was then cleaved via a phloroglucinol pathway, resulting in acetate production, which was then used in exoelectrogenesis. In contrast, more than 80% of VA and HBA was converted to catechol (1,2-dihydroxybenzene) and phenol (hydroxybenzene) as their respective dead-end products. The persistence of catechol and phenol is explained by the fact that the phloroglucinol pathway does not apply to di- or mono-hydroxylated benzenes. Previously reported, alternative ring-cleaving pathways were either absent in the bioanode microbial community or unfavorable due to high energy-demand reactions. With the exception of acetate oxidation, all biotransformation steps in the bioanode occurred via fermentation, independently of exoelectrogenesis. Therefore, the observed

  5. Changes in the Structure of the Microbial Community Associated with Nannochloropsis salina following Treatments with Antibiotics and Bioactive Compounds

    PubMed Central

    Geng, Haifeng; Tran-Gyamfi, Mary B.; Lane, Todd W.; Sale, Kenneth L.; Yu, Eizadora T.

    2016-01-01

    Open microalgae cultures host a myriad of bacteria, creating a complex system of interacting species that influence algal growth and health. Many algal microbiota studies have been conducted to determine the relative importance of bacterial taxa to algal culture health and physiological states, but these studies have not characterized the interspecies relationships in the microbial communities. We subjected Nanochroloropsis salina cultures to multiple chemical treatments (antibiotics and quorum sensing compounds) and obtained dense time-series data on changes to the microbial community using 16S gene amplicon metagenomic sequencing (21,029,577 reads for 23 samples) to measure microbial taxa-taxa abundance correlations. Short-term treatment with antibiotics resulted in substantially larger shifts in the microbiota structure compared to changes observed following treatment with signaling compounds and glucose. We also calculated operational taxonomic unit (OTU) associations and generated OTU correlation networks to provide an overview of possible bacterial OTU interactions. This analysis identified five major cohesive modules of microbiota with similar co-abundance profiles across different chemical treatments. The Eigengenes of OTU modules were examined for correlation with different external treatment factors. This correlation-based analysis revealed that culture age (time) and treatment types have primary effects on forming network modules and shaping the community structure. Additional network analysis detected Alteromonadeles and Alphaproteobacteria as having the highest centrality, suggesting these species are “keystone” OTUs in the microbial community. Furthermore, we illustrated that the chemical tropodithietic acid, which is secreted by several species in the Alphaproteobacteria taxon, is able to drastically change the structure of the microbiota within 3 h. Taken together, these results provide valuable insights into the structure of the microbiota

  6. Changes in the Structure of the Microbial Community Associated with Nannochloropsis salina following Treatments with Antibiotics and Bioactive Compounds

    SciTech Connect

    Geng, Haifeng; Tran-Gyamfi, Mary B.; Lane, Todd W.; Sale, Kenneth L.; Yu, Eizadora T.

    2016-07-26

    Open microalgae cultures host a myriad of bacteria, creating a complex system of interacting species that influence algal growth and health. Many algal microbiota studies have been conducted to determine the relative importance of bacterial taxa to algal culture health and physiological states, but these studies have not characterized the interspecies relationships in the microbial communities. Here we subjected Nanochroloropsis salina cultures to multiple chemical treatments (antibiotics and quorum sensing compounds) and obtained dense time-series data on changes to the microbial community using 16S gene amplicon metagenomic sequencing (21,029,577 reads for 23 samples) to measure microbial taxa-taxa abundance correlations. Short-term treatment with antibiotics resulted in substantially larger shifts in the microbiota structure compared to changes observed following treatment with signaling compounds and glucose. We also calculated operational taxonomic unit (OTU) associations and generated OTU correlation networks to provide an overview of possible bacterial OTU interactions. This analysis identified five major cohesive modules of microbiota with similar co-abundance profiles across different chemical treatments. The Eigengenes of OTU modules were examined for correlation with different external treatment factors. This correlation-based analysis revealed that culture age (time) and treatment types have primary effects on forming network modules and shaping the community structure. Additional network analysis detected Alteromonadeles and Alphaproteobacteria as having the highest centrality, suggesting these species are “keystone” OTUs in the microbial community. Furthermore, we illustrated that the chemical tropodithietic acid, which is secreted by several species in the Alphaproteobacteria taxon, is able to drastically change the structure of the microbiota within 3 h. Lastly, taken together, these results provide valuable insights into the structure of the

  7. Changes in the Structure of the Microbial Community Associated with Nannochloropsis salina following Treatments with Antibiotics and Bioactive Compounds

    DOE PAGES

    Geng, Haifeng; Tran-Gyamfi, Mary B.; Lane, Todd W.; ...

    2016-07-26

    Open microalgae cultures host a myriad of bacteria, creating a complex system of interacting species that influence algal growth and health. Many algal microbiota studies have been conducted to determine the relative importance of bacterial taxa to algal culture health and physiological states, but these studies have not characterized the interspecies relationships in the microbial communities. Here we subjected Nanochroloropsis salina cultures to multiple chemical treatments (antibiotics and quorum sensing compounds) and obtained dense time-series data on changes to the microbial community using 16S gene amplicon metagenomic sequencing (21,029,577 reads for 23 samples) to measure microbial taxa-taxa abundance correlations. Short-termmore » treatment with antibiotics resulted in substantially larger shifts in the microbiota structure compared to changes observed following treatment with signaling compounds and glucose. We also calculated operational taxonomic unit (OTU) associations and generated OTU correlation networks to provide an overview of possible bacterial OTU interactions. This analysis identified five major cohesive modules of microbiota with similar co-abundance profiles across different chemical treatments. The Eigengenes of OTU modules were examined for correlation with different external treatment factors. This correlation-based analysis revealed that culture age (time) and treatment types have primary effects on forming network modules and shaping the community structure. Additional network analysis detected Alteromonadeles and Alphaproteobacteria as having the highest centrality, suggesting these species are “keystone” OTUs in the microbial community. Furthermore, we illustrated that the chemical tropodithietic acid, which is secreted by several species in the Alphaproteobacteria taxon, is able to drastically change the structure of the microbiota within 3 h. Lastly, taken together, these results provide valuable insights into the structure

  8. Do secondary compounds inhibit microbial- and insect-mediated leaf breakdown in a tropical rainforest stream, Costa Rica?

    PubMed

    Ardón, Marcelo; Pringle, Catherine M

    2008-03-01

    We examined the hypothesis that high concentrations of secondary compounds in leaf litter of some tropical riparian tree species decrease leaf breakdown by inhibiting microbial and insect colonization. We measured leaf breakdown rates, chemical changes, bacterial, fungal, and insect biomass on litterbags of eight species of common riparian trees incubated in a lowland stream in Costa Rica. The eight species spanned a wide range of litter quality due to varying concentrations of nutrients, structural and secondary compounds. Leaf breakdown rates were fast, ranging from 0.198 d(-1 )(Trema integerrima) to 0.011 d(-1) (Zygia longifolia). Processing of individual chemical constituents was also rapid: cellulose was processed threefold faster and hemicellulose was processed fourfold faster compared to similar studies in temperate streams. Leaf toughness (r = -0.86, P = 0.01) and cellulose (r = -0.78, P = 0.02) were the physicochemical parameters most strongly correlated with breakdown rate. Contrary to our initial hypothesis, secondary compounds were rapidly leached (threefold faster than in temperate studies), with all species losing all secondary compounds within the first week of incubation. Cellulose was more important than secondary compounds in inhibiting breakdown. Levels of fungal and bacterial biomass were strongly correlated with breakdown rate (fungi r = 0.64, P = 0.05; bacteria r = 0.93, P < 0.001) and changes in structural compounds (lignin r = -0.55, P = 0.01). Collector-gatherers were the dominant functional group of insects colonizing litterbags, in contrast to temperate studies where insect shredders dominate. Insect biomass was negatively correlated with breakdown rate (r = -0.70, P = 0.02), suggesting that insects did not play an important role in breakdown. Despite a wide range of initial concentrations of secondary compounds among the eight species used, we found that secondary compounds were rapidly leached and were less important than structural

  9. Characterization of microbial and chemical composition of shuttle wet waste with permanent gas and volatile organic compound analyses

    NASA Astrophysics Data System (ADS)

    Peterson, B. V.; Hummerick, M.; Roberts, M. S.; Krumins, V.; Kish, A. L.; Garland, J. L.; Maxwell, S.; Mills, A.

    2004-01-01

    Solid-waste treatment in space for Advanced Life Support, ALS, applications requires that the material can be safely processed and stored in a confined environment. Many solid-wastes are not stable because they are wet (40-90% moisture) and contain levels of soluble organic compounds that can contribute to the growth of undesirable microorganisms with concomitant production of noxious odors. In the absence of integrated Advanced Life Support systems on orbit, permanent gas, trace volatile organic and microbiological analyses were performed on crew refuse returned from the volume F "wet" trash of three consecutive Shuttle missions (STS-105, 109, and 110). These analyses were designed to characterize the short-term biological stability of the material and assess potential crew risks resulting from microbial decay processes during storage. Waste samples were collected post-orbiter landing and sorted into packaging material, food waste, toilet waste, and bulk liquid fractions deposited during flight in the volume F container. Aerobic and anaerobic microbial loads were determined in each fraction by cultivation on R2A and by acridine orange direct count (AODC). Dry and ash weights were performed to determine both water and organic content of the materials. Experiments to determine the aerobic and anaerobic biostability of refuse stored for varying periods of time were performed by on-line monitoring of CO 2 and laboratory analysis for production of hydrogen sulfide and methane. Volatile organic compounds and permanent gases were analyzed using EPA Method TO15 by USEPA et al. [EPA Method TO15, The Determination of Volatile Organic Compounds (VOCs) in Ambient Air using SUMMA, Passivated Canister Sampling and Gas Chromatographic Analysis, 1999] with gas chromatography/mass spectrometry and by gas chromatography with selective detectors. These baseline measures of waste stream content, labile organics, and microbial load in the volume F Shuttle trash provide data for waste

  10. Characterization of microbial and chemical composition of shuttle wet waste with permanent gas and volatile organic compound analyses.

    PubMed

    Peterson, B V; Hummerick, M; Roberts, M S; Krumins, V; Kish, A L; Garland, J L; Maxwell, S; Mills, A

    2004-01-01

    Solid-waste treatment in space for Advanced Life Support, ALS, applications requires that the material can be safely processed and stored in a confined environment. Many solid-wastes are not stable because they are wet (40-90% moisture) and contain levels of soluble organic compounds that can contribute to the growth of undesirable microorganisms with concomitant production of noxious odors. In the absence of integrated Advanced Life Support systems on orbit, permanent gas, trace volatile organic and microbiological analyses were performed on crew refuse returned from the volume F "wet" trash of three consecutive Shuttle missions (STS-105, 109, and 110). These analyses were designed to characterize the short-term biological stability of the material and assess potential crew risks resulting from microbial decay processes during storage. Waste samples were collected post-orbiter landing and sorted into packaging material, food waste, toilet waste, and bulk liquid fractions deposited during flight in the volume F container. Aerobic and anaerobic microbial loads were determined in each fraction by cultivation on R2A and by acridine orange direct count (AODC). Dry and ash weights were performed to determine both water and organic content of the materials. Experiments to determine the aerobic and anaerobic biostability of refuse stored for varying periods of time were performed by on-line monitoring of CO2 and laboratory analysis for production of hydrogen sulfide and methane. Volatile organic compounds and permanent gases were analyzed using EPA Method TO15 by USEPA et al. [EPA Method TO15, The Determination of Volatile Organic Compounds (VOCs) in Ambient Air using SUMMA, Passivated Canister Sampling and Gas Chromatographic Analysis,1999] with gas chromatography/mass spectrometry and by gas chromatography with selective detectors. These baseline measures of waste stream content, labile organics, and microbial load in the volume F Shuttle trash provide data for waste

  11. Characterization of microbial and chemical composition of shuttle wet waste with permanent gas and volatile organic compound analyses

    NASA Technical Reports Server (NTRS)

    Peterson, B. V.; Hummerick, M.; Roberts, M. S.; Krumins, V.; Kish, A. L.; Garland, J. L.; Maxwell, S.; Mills, A.

    2004-01-01

    Solid-waste treatment in space for Advanced Life Support, ALS, applications requires that the material can be safely processed and stored in a confined environment. Many solid-wastes are not stable because they are wet (40-90% moisture) and contain levels of soluble organic compounds that can contribute to the growth of undesirable microorganisms with concomitant production of noxious odors. In the absence of integrated Advanced Life Support systems on orbit, permanent gas, trace volatile organic and microbiological analyses were performed on crew refuse returned from the volume F "wet" trash of three consecutive Shuttle missions (STS-105, 109, and 110). These analyses were designed to characterize the short-term biological stability of the material and assess potential crew risks resulting from microbial decay processes during storage. Waste samples were collected post-orbiter landing and sorted into packaging material, food waste, toilet waste, and bulk liquid fractions deposited during flight in the volume F container. Aerobic and anaerobic microbial loads were determined in each fraction by cultivation on R2A and by acridine orange direct count (AODC). Dry and ash weights were performed to determine both water and organic content of the materials. Experiments to determine the aerobic and anaerobic biostability of refuse stored for varying periods of time were performed by on-line monitoring of CO2 and laboratory analysis for production of hydrogen sulfide and methane. Volatile organic compounds and permanent gases were analyzed using EPA Method TO15 by USEPA et al. [EPA Method TO15, The Determination of Volatile Organic Compounds (VOCs) in Ambient Air using SUMMA, Passivated Canister Sampling and Gas Chromatographic Analysis,1999] with gas chromatography/mass spectrometry and by gas chromatography with selective detectors. These baseline measures of waste stream content, labile organics, and microbial load in the volume F Shuttle trash provide data for waste

  12. Compound-specific Isotope Analysis of Cyanobacterial Pure cultures and Microbial Mats: Effects of Photorespiration?

    NASA Technical Reports Server (NTRS)

    Jahnke, L. L.; Summons, R. E.

    2006-01-01

    Microbial mats are considered modern homologs of Precambrian stromatolites. The carbon isotopic compositions of organic matter and biomarker lipids provide clues to the depositional environments of ancient mat ecosystems. As the source of primary carbon fixation for over two billion years, an understanding of cyanobacterial lipid biosynthesis, associated isotopic discriminations, and the influence of physiological factors on growth and isotope expression is essential to help us compare modern microbial ecosystems to their ancient counterparts. Here, we report on the effects of photorespiration (PR) on the isotopic composition of cyanobacteria and biomarker lipids, and on potential PR effects associated with the composition of various microbial mats. The high light, high O2 and limiting CO2 conditions often present at the surface of microbial mats are known to support PR in cyanobacteria. The oxygenase function of ribulose bisphosphate carboxylase/oxygenase can result in photoexcretion of glycolate and subsequent degration by heterotrophic bacteria. We have found evidence which supports an isotopic depletion (increased apparent E) scaled to O2 level associated with growth of Phormidium luridum at low CO2 concentrations (less than 0.04%). Similar to previous studies, isotopic differences between biomass and lipid biomarkers, and between lipid classes were positively correlated with overall fractionation, and should provide a means of estimating the influence of PR on overall isotopic composition of microbial mats. Several examples of microbial mats growing in the hydrothermal waters of Yellowstone National Park and the hypersaline marine evaporation ponds at Guerrero Negro, Baja Sur Mexico will be compared with a view to PR as a possible explanation of the relatively heavy C-isotope composition of hypersaline mats.

  13. Study on the synergic effect of natural compounds on the microbial quality decay of packed fish hamburger.

    PubMed

    Corbo, M R; Speranza, B; Filippone, A; Granatiero, S; Conte, A; Sinigaglia, M; Del Nobile, M A

    2008-10-31

    The effectiveness of natural compounds in slowing down the microbial quality decay of refrigerated fish hamburger is addressed in this study. In particular, the control of the microbiological spoilage by combined use of three antimicrobials, and the determination of their optimal composition to extend the fish hamburger Microbiological Stability Limit (MAL) are the main objectives of this work. Thymol, grapefruit seed extract (GFSE) and lemon extract were tested for monitoring the cell growth of the main fish spoilage microorganisms (Pseudomonas fluorescens, Photobacterium phosphoreum and Shewanella putrefaciens), inoculated in fish hamburgers, and the growth of mesophilic and psychrotrophic bacteria. A Central Composite Design (CCD) was developed to highlight a possible synergic effect of the above natural compounds. Results showed an increase in the MAL value for hamburgers mixed with the antimicrobial compounds, compared to the control sample. The optimal antimicrobial compound composition, which corresponds to the maximal MAL value determined in this study, is: 110 mgL(-1) of thymol, 100 mgL(-1) of GFSE and 120 mgL(-1) of lemon extract. The presence of the natural compounds delay the sensorial quality decay without compromising the flavor of the fish hamburgers.

  14. [On Atomic Nuclear Fusion Processes at Low-Temperatures. An Enhancement of the Probability of Transition through a Potential Barrier Due to the So-Called Barrier Anti-Zeno Effect].

    PubMed

    Namiot, V A

    2016-01-01

    It is known that in quantum mechanics the act of observing the experiment can affect the experimental findings in some cases. In particular, it happens under the so-called Zeno effect. In this work it is shown that in contrast to the "standard" Zeno-effect where the act of observing a process reduces the probability of its reality, an inverse situation when a particle transmits through a potential barrier (a so-called barrier anti-Zeno effect) can be observed, the observation of the particle essentially increases the probability of its transmission through the barrier. The possibility of using the barrier anti-Zeno effect is discussed to explain paradoxical results of experiments on "cold nuclear fusion" observed in various systems including biological ones. (According to the observers who performed the observations, the energy generation, which could not be explained by any chemical processes, as well as the change in the isotope and even element composition of the studied object may occur in these systems.

  15. Microbial toxicity of the insensitive munitions compound, 2,4-dinitroanisole (DNAN), and its aromatic amine metabolites.

    PubMed

    Liang, Jidong; Olivares, Christopher; Field, Jim A; Sierra-Alvarez, Reyes

    2013-11-15

    2,4-Dinitroanisole (DNAN) is an insensitive munitions compound considered to replace conventional explosives such as 2,4,6-trinitrotoluene (TNT). DNAN undergoes facile microbial reduction to 2-methoxy-5-nitroaniline (MENA) and 2,4-diaminoanisole (DAAN). This study investigated the inhibitory effect of DNAN, MENA, and DAAN toward various microbial targets in anaerobic (acetoclastic methanogens) and aerobic (heterotrophs and nitrifiers) sludge, and the bioluminescent bacterium, Aliivibrio fischeri, used in the Microtox assay. Aerobic heterotrophic and nitrifying batch experiments with DAAN could not be performed because the compound underwent extensive autooxidation in these assays. DNAN severely inhibited methanogens, nitrifying bacteria, and A. fischeri (50% inhibitory concentrations (IC50) ranging 41-57μM), but was notably less inhibitory to aerobic heterotrophs (IC50>390 μM). Reduction of DNAN to MENA and DAAN lead to a marked decrease in methanogenic inhibition (i.e., DNAN>MENA≈DAAN). Reduction of all nitro groups in DNAN also resulted in partial detoxification in assays with A. fischeri. In contrast, reduction of a single nitro group did not alter the inhibitory impact of DNAN toward A. fischeri and nitrifying bacteria given the similar IC50 values determined for MENA and DNAN in these assays. These results indicate that reductive biotransformation could reduce the inhibitory potential of DNAN.

  16. Deciphering Microbial Carbon Sources in Petroleum Contaminated Sediments Using Compound Specific Radiocarbon Analysis

    NASA Astrophysics Data System (ADS)

    Morrill, P. L.; Szponar, N.; Maunder, C.; Marvin, C.; Slater, G. F.

    2008-12-01

    Microbial membrane phospholipid fatty acids (PLFAs) were analyzed to investigate microbial carbon sources and assess the impact of petroleum hydrocarbon contamination in one of North America's most contaminated harbours. Sediment cores were sampled from two locations in the harbour: a highly impacted area, Dofasco Boat Slip; and a less impacted area, Carole's Bay. Natural organic matter (NOM) and total petroleum hydrocarbons (TPHs) were two possible organic carbon sources for microbial metabolisms. While the majority of organic carbon (OC) at both Dofasco and Carole's Bay was NOM, petroleum hydrocarbons also contributed to the OC. As expected, the concentration of the TPHs was much greater at the Dofasco site (270 ug/g) compared to the TPHs concentration measured at Carole's Bay (50 ug/g). However, the % of PAHs that contributed to TPHs was very similar in the first three centimeters at both sites (9%). The PLFAs distributions at Carole's Bay and Dofasco were fairly similar indicating an overall bulk similarity between the communities notwithstanding higher contaminant concentrations at the Dofasco site. PLFA distributions changed with depth, consistent with changes in redox conditions from oxic to anoxia. The PLFAs extracted from the upper 3 cm of sediment from Carole's Bay had modern cap delta 14C values (with an average value of -66 ) compared to both the NOM (cap delta 14C -132 ) and TPH (cap delta 14C -775 ), suggesting that the carbon substrate for microbial metabolisms was a younger more labile source. The cap delta 14C isotopic values between individual PLFAs were indistinguishable (within the standard error of 20 for accuracy and reproducibility) demonstrating that if TPHs were degraded the impact on the cap delta 14C was not resolvable at Carole's Bay. Co-metabolic degradation of petroleum hydrocarbons is one possible degradation mechanism whereby biodegradation is occurring, but the contaminant carbon may not be incorporated into the microbial membrane

  17. Comparison of the morphology of alkali–silica gel formed in limestones in concrete affected by the so-called alkali–carbonate reaction (ACR) and alkali–silica reaction (ASR)

    SciTech Connect

    Grattan-Bellew, P.E.; Chan, Gordon

    2013-05-15

    The morphology of alkali–silica gel formed in dolomitic limestone affected by the so-called alkali–carbonate reaction (ACR) is compared to that formed in a siliceous limestone affected by alkali–silica reaction (ASR). The particle of dolomitic limestone was extracted from the experimental sidewalk in Kingston, Ontario, Canada that was badly cracked due to ACR. The siliceous limestone particle was extracted from a core taken from a highway structure in Quebec, affected by ASR. Both cores exhibited marked reaction rims around limestone particles. The aggregate particles were polished and given a light gold coating in preparation for examination in a scanning electron microscope. The gel in the ACR aggregate formed stringers between the calcite crystals in the matrix of the rock, whereas gel in ASR concrete formed a thick layer on top of the calcite crystals, that are of the same size as in the ACR aggregate.

  18. Effect of sweating set rate on clothing real evaporative resistance determined on a sweating thermal manikin in a so-called isothermal condition (T manikin = T a = T r).

    PubMed

    Lu, Yehu; Wang, Faming; Peng, Hui; Shi, Wen; Song, Guowen

    2016-04-01

    The ASTM F2370 (2010) is the only standard with regard to measurement of clothing real evaporative resistance by means of a sweating manikin. However, the sweating set-point is not recommended in the standard. In this study, the effect of sweating rate on clothing real evaporative resistance was investigated on a 34-zone "Newton" sweating thermal manikin in a so-called isothermal condition (T manikin = T a = T r). Four different sweating set rates (i.e., all segments had a sweating rate of 400, 800, 1200 ml/hr ∙ m(2), respectively, and different sweating rates were assigned to different segments) were applied to determine the clothing real evaporative resistance of five clothing ensembles and the boundary air layer. The results indicated that the sweating rate did not affect the real evaporative resistance of clothing ensembles with the absence of strong moisture absorbent layers. For the clothing ensemble with tight cotton underwear, a sweating rate of lower than 400 ml/hr ∙ m(2) is not recommended. This is mainly because the wet fabric "skin" might not be fully saturated and thus led to a lower evaporative heat loss and thereby a higher real evaporative resistance. For vapor permeable clothing, the real evaporative resistance determined in the so-called isothermal condition should be corrected before being used in thermal comfort or heat strain models. However, the reduction of wet thermal insulation due to moisture absorption in different test scenarios had a limited contribution to the effect of sweating rate on the real evaporative resistance.

  19. Effect of sweating set rate on clothing real evaporative resistance determined on a sweating thermal manikin in a so-called isothermal condition ( T manikin = T a = T r)

    NASA Astrophysics Data System (ADS)

    Lu, Yehu; Wang, Faming; Peng, Hui; Shi, Wen; Song, Guowen

    2016-04-01

    The ASTM F2370 (2010) is the only standard with regard to measurement of clothing real evaporative resistance by means of a sweating manikin. However, the sweating set-point is not recommended in the standard. In this study, the effect of sweating rate on clothing real evaporative resistance was investigated on a 34-zone "Newton" sweating thermal manikin in a so-called isothermal condition ( T manikin = T a = T r). Four different sweating set rates (i.e., all segments had a sweating rate of 400, 800, 1200 ml/hr•m2, respectively, and different sweating rates were assigned to different segments) were applied to determine the clothing real evaporative resistance of five clothing ensembles and the boundary air layer. The results indicated that the sweating rate did not affect the real evaporative resistance of clothing ensembles with the absence of strong moisture absorbent layers. For the clothing ensemble with tight cotton underwear, a sweating rate of lower than 400 ml/hr•m2 is not recommended. This is mainly because the wet fabric "skin" might not be fully saturated and thus led to a lower evaporative heat loss and thereby a higher real evaporative resistance. For vapor permeable clothing, the real evaporative resistance determined in the so-called isothermal condition should be corrected before being used in thermal comfort or heat strain models. However, the reduction of wet thermal insulation due to moisture absorption in different test scenarios had a limited contribution to the effect of sweating rate on the real evaporative resistance.

  20. A macrophage-stimulating compound from a screen of microbial natural products.

    PubMed

    Perry, Julie A; Koteva, Kalinka; Verschoor, Chris P; Wang, Wenliang; Bowdish, Dawn M E; Wright, Gerry D

    2015-01-01

    Rising rates of antibiotic resistance in bacterial pathogens is a medical crisis of global concern that necessitates the development of new treatment strategies. We have isolated a natural product with macrophage-stimulating activity from a screen of microbially produced bioactive molecules. Streptazolin increased bacterial killing and elaboration of immunostimulatory cytokines by macrophages in vitro. Furthermore, we show that streptazolin stimulates the macrophage nuclear factor κB (NF-κB) pathway via phosphatidylinositide 3-kinase (PI3K) signaling, and that the conjugated diene moiety is essential for stimulatory activity. Immunostimulatory molecules like streptazolin represent entries into new treatment paradigms to address the challenge of antibiotic resistance.

  1. Bioconversion of lutein using a microbial mixture--maximizing the production of tobacco aroma compounds by manipulation of culture medium.

    PubMed

    Rodríguez-Bustamante, Eduardo; Maldonado-Robledo, Gabriela; Ortiz, Marco Antonio; Díaz-Avalos, Carlos; Sanchez, Sergio

    2005-08-01

    The generation of aroma compounds by carotenoid cleavage in the 9-10 position was studied, due to the importance of these compounds in the flavor and fragrance industry. The bioconversion of the carotenoid lutein to C(13) norisoprenoids utilizing a microbial mixture composed of Trichosporon asahii and Paenibacillus amylolyticus was carried out by a fermentation process. Applying an experimental design methodology, the effects of nutritional factors on the production of aroma compounds present in the tobacco profile were studied. After an assessment of the significance of each nutritional factor, the levels of the variables yielding the maximum response were calculated. Glucose, tryptone, and yeast extract exerted a strong negative effect over the objective function, with glucose being the strongest. Lutein possessed a positive effect over the tobacco aroma production, while sodium chloride and trace elements showed no influence over the process. The yield attained after culture medium manipulation was almost ten-fold higher, compared with the base medium; and the aroma mixture was characterized as: 7,8-dihydro-beta-ionol (95.2%), 7,8-dihydro-beta-ionone (3.7%), and beta-ionone (1.1%).

  2. Microbial desizing using starch as model compound: enzyme properties and desizing efficiency.

    PubMed

    Feitkenhauer, Heiko; Fischer, Daniel; Fäh, Daniel

    2003-01-01

    A film of sizing agents protects yarn during weaving. Its removal in a subsequent washing process causes 50% of the organic effluent load of textile finishing processes and requires large amounts of auxiliary chemicals (e.g., surfactants). Microbial desizing is a new bioprocess that uses the acidifying culture of a two-phase anaerobic digestion plant for the removal and partial degradation (acidification) of the sizing agent. Soluble starch is used in this study to characterize the enzymatic properties in the supernatant of the desizing culture and to link them to desizing efficiencies. The supernatant of the culture (grown at 37 degrees C, pH 5.5) displayed the highest enzymatic activity between pH 4 and 5 and in a broad temperature range (20-80 degrees C). Highest metabolization rates were determined with the substrate amylose. Short chain dextrins (average of 5 and 10 glucose units) and amylopectin were converted significantly more slowly. At 37 degrees C the half-life time of the enzymatic activity in the supernatant was 45 h. In a desizing test a decisive reduction of the chain length was found already after 1 h (allowing starch solubilization). A microbial desizing experiment with dyed, native maize starch demonstrated the efficiency of the proposed bioprocess.

  3. Microbial degradation of dimethylsulphide and related C1-sulphur compounds: organisms and pathways controlling fluxes of sulphur in the biosphere.

    PubMed

    Schäfer, Hendrik; Myronova, Natalia; Boden, Rich

    2010-01-01

    Dimethylsulphide (DMS) plays a major role in the global sulphur cycle. It has important implications for atmospheric chemistry, climate regulation, and sulphur transport from the marine to the atmospheric and terrestrial environments. In addition, DMS acts as an info-chemical for a wide range of organisms ranging from micro-organisms to mammals. Micro-organisms that cycle DMS are widely distributed in a range of environments, for instance, oxic and anoxic marine, freshwater and terrestrial habitats. Despite the importance of DMS that has been unearthed by many studies since the early 1970s, the understanding of the biochemistry, genetics, and ecology of DMS-degrading micro-organisms is still limited. This review examines current knowledge on the microbial cycling of DMS and points out areas for future research that should shed more light on the role of organisms degrading DMS and related compounds in the biosphere.

  4. Microbial transformation of ginsenoside Rb1 to compound K by Lactobacillus paralimentarius.

    PubMed

    Quan, Lin-Hu; Kim, Yeon-Ju; Li, Guan Hao; Choi, Kwang-Tea; Yang, Deok-Chun

    2013-06-01

    In this study, the major ginsenoside Rb1 was transformed into the more pharmacologically active minor compound K by food grade Lactobacillus paralimentarius LH4, which was isolated from kimchi, a traditional Korean fermented food. The enzymatic reaction was analyzed by TLC, HPLC, and NMR. Using the cell-free enzyme of Lactobacillus paralimentarius LH4 at optimal conditions for 30 °C at pH 6.0, 1.0 mg ml(-1) ginsenoside Rb1 was transformed into 0.52 mg ml(-1) compound K within 72 h, with a corresponding molar conversion yield of 88 %. The cell-free enzyme hydrolyzed the two glucose moieties attached to the C-3 position and the outer glucose moiety attached to the C-20 position of the ginsenoside Rb1. The cell-free enzyme hydrolyzed the ginsenoside Rb1 along the following pathway: ginsenoside Rb1 → gypenoside XVII and ginsenoside Rd → ginsenoside F2 → compound K. Our results indicate that Lactobacillus paralimentarius LH4 has the potential to be applied for the preparation of compound K in the food industry.

  5. Performance evaluation of a continuous-flow bioanode microbial electrolysis cell fed with furanic and phenolic compounds

    DOE PAGES

    Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

    2016-07-04

    Furanic and phenolic compounds, formed during the pretreatment of lignocellulosic biomass, are problematic byproducts in down-stream biofuel processes. A microbial electrolysis cell (MEC) is an alternative technology to handle furanic and phenolic compounds and produce renewable hydrogen (H2). In this study, we evaluated the performance of a continuous-flow bioanode MEC fed with furanic and phenolic compounds at different operating conditions. All hydraulic retention times (HRTs) tested (6-24 h) resulted in complete transformation of the parent compounds at an organic loading rate (OLR) of 0.2g L-1 per d and applied voltage of 0.6 V. Increasing the OLR to 0.8 g L-1more » per d at an HRT of 6h resulted in an increased H2 production rate from 0.07 to 0.14 L Lanode 1 per d, but an OLR of 3.2 g L-1 per d did not lead to a higher H2 production rate. Significant methane production was observed at an OLR of 3.2 g L-1 per d. The lack of increased H2 production at the highest OLR tested was due to a limited rate of exoelectrogenesis but not fermentation, evidenced by the accumulation of high acetate levels and higher growth of fermenters and methanogens over exoelectrogens. Increasing applied voltage from 0.6 to 1.0V at an OLR of 3.2 g L-1 per d and HRT of 6h enhanced exoelectrogenesis and resulted in a 1.7-fold increase of H2 production. Under all operating conditions, more than 90% of the biomass was biofilm-associated. Lastly, the present study provides new insights into the performance of continuous-flow bioelectrochemical systems fed with complex waste streams resulting from the pretreatment of lignocellulosic biomass.« less

  6. Metabolic engineering for microbial production of aromatic amino acids and derived compounds.

    PubMed

    Bongaerts, J; Krämer, M; Müller, U; Raeven, L; Wubbolts, M

    2001-10-01

    Metabolic engineering to design and construct microorganisms suitable for the production of aromatic amino acids and derivatives thereof requires control of a complicated network of metabolic reactions that partly act in parallel and frequently are in rapid equilibrium. Engineering the regulatory circuits, the uptake of carbon, the glycolytic pathway, the pentose phosphate pathway, and the common aromatic amino acid pathway as well as amino acid importers and exporters that have all been targeted to effect higher productivities of these compounds are discussed.

  7. Formation and emission of volatile polonium compound by microbial activity and polonium methylation with methylcobalamin.

    PubMed

    Momoshima, N; Song, L X; Osaki, S; Maeda, Y

    2001-07-15

    We observed biologically mediated emission of Po from culture solution inoculated sea sediment extract and incubated under natural light/dark cycle condition or dark condition the emitted Po compound would be lipophilic because of effective collection in organic solvent. Sterilization of the culture medium with antibiotics or CuSO4 completely suppressed growth of microorganisms and resulted in no emission of Po, indicating biological activity of microorganisms is responsible for formation and emission of volatile Po compound. Po emission also occurred when seawater was used as a culture medium. Our finding indicates a possibility of biotic source for atmospheric Po in the environment, which has been believed to be originated from abiotic sources. We compared emission behavior of Po and S in the culture experiments, the elements belong to XVI group in the Periodical Table, and consider that their emission mechanisms involved would be different though the emission of both elements is supported by biological activity of microorganisms. One of the chemical forms of S emitted was confirmed to be dimethyl sulfide (DMS) but that of Po is not known. Methylation experiments of Po with methylcobalamin demonstrated a formation and emission of volatile Po compound. The methylation of Po with methylcobalamin might be related to the observed Po emission in the culture experiments.

  8. Microbial utilization of sugars in soil assessed by position-specific labeling and compound-specific 13C-PLFA-analysis

    NASA Astrophysics Data System (ADS)

    Apostel, Carolin; Dippold, Michaela; Glaser, Bruno; Kuzyakov, Yakov

    2014-05-01

    For the transformation of low molecular weight organic substances (LMWOS) in soil, which is an important process in the turnover of organic matter, microbial utilization is one of the most important processes. Position-specific labeling combined with compound-specific 13C-PLFA-analysis allows a closer look on the mechanisms of LMWOS transformation in soil. We assessed short- (3 and 10 days) and long-term (half year) transformations of monosaccharides by adding position-specifically 13C labeled glucose and ribose to soil in a field experiment conducted on an agriculturally used luvisol located in north-western Bavaria. We quantified the microbial utilization of the different functional groups by 13C-analysis of microbial biomass with the chloroform-fumigation-extraction method (CFE). 13C-PLFA analysis enabled us to distinguish individual microbial groups and compare their C-utilization. Preferential degradation of glucoses C-3 and C-4 respectively C-1 position enabled differentiation between the two main hexose metabolic pathways - glycolysis and the pentose phosphate pathway. Microbial groups revealed different incorporation of specific C positions into their PLFA. The highest incorporation was reached by the prokaryotic gram- negative groups. The application of position-specifically labeled substances, coupled with compound-specific 13C-PLFA analysis opens a new way to investigate the microbial transformations of LMWOS in soil. Observing single C atoms and their utilization by specific microbial groups allow conclusions about the mechanisms and kinetics of microbial utilization and interaction between these groups and therefore will improve our understanding of soil carbon fluxes.

  9. Methanogenic degradation of lignin-derived monoaromatic compounds by microbial enrichments from rice paddy field soil.

    PubMed

    Kato, Souichiro; Chino, Kanako; Kamimura, Naofumi; Masai, Eiji; Yumoto, Isao; Kamagata, Yoichi

    2015-09-24

    Anaerobic degradation of lignin-derived aromatics is an important metabolism for carbon and nutrient cycles in soil environments. Although there are some studies on degradation of lignin-derived aromatics by nitrate- and sulfate-reducing bacteria, knowledge on their degradation under methanogenic conditions are quite limited. In this study, methanogenic microbial communities were enriched from rice paddy field soil with lignin-derived methoxylated monoaromatics (vanillate and syringate) and their degradation intermediates (protocatechuate, catechol, and gallate) as the sole carbon and energy sources. Archaeal community analysis disclosed that both aceticlastic (Methanosarcina sp.) and hydrogenotrophic (Methanoculleus sp. and Methanocella sp.) methanogens dominated in all of the enrichments. Bacterial community analysis revealed the dominance of acetogenic bacteria (Sporomusa spp.) only in the enrichments on the methoxylated aromatics, suggesting that Sporomusa spp. initially convert vanillate and syringate into protocatechuate and gallate, respectively, with acetogenesis via O-demethylation. As the putative ring-cleavage microbes, bacteria within the phylum Firmicutes were dominantly detected from all of the enrichments, while the dominant phylotypes were not identical between enrichments on vanillate/protocatechuate/catechol (family Peptococcaceae bacteria) and on syringate/gallate (family Ruminococcaceae bacteria). This study demonstrates the importance of cooperation among acetogens, ring-cleaving fermenters/syntrophs and aceticlastic/hydrogenotrophic methanogens for degradation of lignin-derived aromatics under methanogenic conditions.

  10. Methanogenic degradation of lignin-derived monoaromatic compounds by microbial enrichments from rice paddy field soil

    PubMed Central

    Kato, Souichiro; Chino, Kanako; Kamimura, Naofumi; Masai, Eiji; Yumoto, Isao; Kamagata, Yoichi

    2015-01-01

    Anaerobic degradation of lignin-derived aromatics is an important metabolism for carbon and nutrient cycles in soil environments. Although there are some studies on degradation of lignin-derived aromatics by nitrate- and sulfate-reducing bacteria, knowledge on their degradation under methanogenic conditions are quite limited. In this study, methanogenic microbial communities were enriched from rice paddy field soil with lignin-derived methoxylated monoaromatics (vanillate and syringate) and their degradation intermediates (protocatechuate, catechol, and gallate) as the sole carbon and energy sources. Archaeal community analysis disclosed that both aceticlastic (Methanosarcina sp.) and hydrogenotrophic (Methanoculleus sp. and Methanocella sp.) methanogens dominated in all of the enrichments. Bacterial community analysis revealed the dominance of acetogenic bacteria (Sporomusa spp.) only in the enrichments on the methoxylated aromatics, suggesting that Sporomusa spp. initially convert vanillate and syringate into protocatechuate and gallate, respectively, with acetogenesis via O-demethylation. As the putative ring-cleavage microbes, bacteria within the phylum Firmicutes were dominantly detected from all of the enrichments, while the dominant phylotypes were not identical between enrichments on vanillate/protocatechuate/catechol (family Peptococcaceae bacteria) and on syringate/gallate (family Ruminococcaceae bacteria). This study demonstrates the importance of cooperation among acetogens, ring-cleaving fermenters/syntrophs and aceticlastic/hydrogenotrophic methanogens for degradation of lignin-derived aromatics under methanogenic conditions. PMID:26399549

  11. Characterization of soluble microbial products (SMPs) in a membrane bioreactor (MBR) treating synthetic wastewater containing pharmaceutical compounds.

    PubMed

    Zhang, Dongqing; Trzcinski, Antoine Prandota; Kunacheva, Chinagarn; Stuckey, David C; Liu, Yu; Tan, Soon Keat; Ng, Wun Jern

    2016-10-01

    This study investigated the behaviour and characteristics of soluble microbial products (SMP) in two anoxic-aerobic membrane bioreactors (MBRs): MBRcontrol and MBRpharma, for treating municipal wastewater. Both protein and polysaccharides measured exhibited higher concentrations in the MBRpharma than the MBRcontrol. Molecular weight (MW) distribution analysis revealed that the presence of pharmaceuticals enhanced the accumulation of SMPs with macro- (13,091 kDa and 1587 kDa) and intermediate-MW (189 kDa) compounds in the anoxic MBRpharma, while a substantial decrease was observed in both MBR effluents. Excitation emission matrix (EEM) fluorescence contours indicated that the exposure to pharmaceuticals seemed to stimulate the production of aromatic proteins containing tyrosine (10.1-32.6%) and tryptophan (14.7-43.1%), compared to MBRcontrol (9.9-29.1% for tyrosine; 11.8-42.5% for tryptophan). Gas chromatography-mass spectrometry (GC-MS) analysis revealed aromatics, long-chain alkanes and esters were the predominant SMPs in the MBRs. More peaks were present in the aerobic MBRpharma (196) than anoxic MBRpharma (133). The SMPs identified exhibited both biodegradability and recalcitrance in the MBR treatment processes. Only 8 compounds in the MBRpharma were the same as in the MBRcontrol. Alkanes were the most dominant SMPs (51%) in the MBRcontrol, while aromatics were dominant (40%) in the MBRpharma. A significant decrease in aromatics (from 16 to 7) in the MBRpharma permeate was observed, compared to the aerobic MBRpharma. Approximately 21% of compounds in the aerobic MBRcontrol were rejected by membrane filtration, while this increased to 28% in the MBRpharma.

  12. Methotrexate-Related Epstein-Barr Virus (EBV)-Associated Lymphoproliferative Disorder—So-Called “Hodgkin-Like Lesion”—of the Oral Cavity in a Patient with Rheumatoid Arthritis

    PubMed Central

    Miyazaki, Yuji; Tanaka, Akio; Shigematu, Hisao; Kojima, Masaru; Sakashita, Hideaki; Kusama, Kaoru

    2010-01-01

    Patients affected by autoimmune diseases (rheumatoid arthritis, psoriasis, dermatomyositis) who are treated with methotrexate (MTX) sometimes develop lymphoproliferative disorders (LPDs). In approximately 40% of reported cases, the affected sites have been extranodal, and have included the gastrointestinal tract, skin, lung, kidney, and soft tissues. However, MTX-associated LPD (MTX-LPD) is extremely rare in the oral cavity. Here we report a 69-year-old Japanese woman with rheumatoid arthritis (RA) who developed MTX-LPD resembling Hodgkin’s disease—so-called “Hodgkin-like lesion”—in the left upper jaw. Histopathologically, large atypical lymphoid cells including Hodgkin or Reed-Sternberg-like cells were found to have infiltrated into granulation tissue in the ulcerative oral mucosa. Immunohistochemistry showed that the large atypical cells were positive for CD20, CD30 and Epstein-Barr virus (EBV)-latent infection membrane protein-1 (LMP-1) and negative for CD15. EBV was detected by in situ hybridization (ISH) with EBV-encoded small RNA (EBER), and polymerase chain reaction (PCR) for LMP-1 and EBNA-2 in material taken from the formalin-fixed, paraffin-embedded specimen. To our knowledge, this is the first reported case of MTX-related EBV-associated LPD (MTX-EBVLPD), “Hodgkin-like lesion”, of the oral cavity in a patient with RA. PMID:20676828

  13. The Impact of Proteolytic Pork Hydrolysate on Microbial, Flavor and Free Amino Acids Compounds of Yogurt.

    PubMed

    Lin, Jinzhong; Hua, Baozhen; Xu, Zhiping; Li, Sha; Ma, Chengjie

    2016-01-01

    The aim of this study was to investigate the influence of proteolytic pork hydrolysate (PPH) on yoghurt production by Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Fresh lean pork was cut into pieces and mixed with deionized water and dealt with protease, then the resulting PPH was added to milk to investigate the effects of PPH on yoghurt production. The fermentation time, the viable cell counts, the flavor, free amino acids compounds, and sensory evaluation of yoghurt were evaluated. These results showed that PPH significantly stimulated the growth and acidification of the both bacterial strains. When the content of PPH reached 5% (w/w), the increased acidifying rate occurred, which the fermentation time was one hour less than that of the control, a time saving of up to 20% compared with the control. The viable cell counts, the total free amino acids, and the scores of taste, flavor and overall acceptability in PPH-supplemented yoghurt were higher than the control. Furthermore, the contents of some characteristic flavor compounds including acids, alcohols, aldehydes, ketones and esters were richer than the control. We concluded that the constituents of PPH such as small peptide, vitamins, and minerals together to play the stimulatory roles and result in beneficial effect for the yoghurt starter cultures growth.

  14. The Impact of Proteolytic Pork Hydrolysate on Microbial, Flavor and Free Amino Acids Compounds of Yogurt

    PubMed Central

    Lin, Jinzhong; Hua, Baozhen; Xu, Zhiping; Li, Sha; Ma, Chengjie

    2016-01-01

    The aim of this study was to investigate the influence of proteolytic pork hydrolysate (PPH) on yoghurt production by Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. Fresh lean pork was cut into pieces and mixed with deionized water and dealt with protease, then the resulting PPH was added to milk to investigate the effects of PPH on yoghurt production. The fermentation time, the viable cell counts, the flavor, free amino acids compounds, and sensory evaluation of yoghurt were evaluated. These results showed that PPH significantly stimulated the growth and acidification of the both bacterial strains. When the content of PPH reached 5% (w/w), the increased acidifying rate occurred, which the fermentation time was one hour less than that of the control, a time saving of up to 20% compared with the control. The viable cell counts, the total free amino acids, and the scores of taste, flavor and overall acceptability in PPH-supplemented yoghurt were higher than the control. Furthermore, the contents of some characteristic flavor compounds including acids, alcohols, aldehydes, ketones and esters were richer than the control. We concluded that the constituents of PPH such as small peptide, vitamins, and minerals together to play the stimulatory roles and result in beneficial effect for the yoghurt starter cultures growth. PMID:27621698

  15. Microbial conversion of glycerol to 1,3-propanediol and related compounds

    SciTech Connect

    Cameron, D.C.; Held, A.M.; Zhu, Mei-Ying

    1995-12-01

    Glycerol is a co-product of the conversion of vegetable oils and animal fats to soap, fatty acids, fatty acid esters and biodiesel fuel. We have investigated the use of both native and recombinant microorganisms for the conversion of glycerol to more valuable products. Fed-batch fermentations of glycerol by Klebsiella pneumoniae gave over 50 g/L of 1,3-propanediol (1,3-PD, trimethylene glycol) with high volumetric productivity. Escherichia coli containing genes for glycerol dehydratase and 1,3-PD oxidoreductase from K. pneumoniae also gave 1,3-PD from glycerol, but at a lower level than the native organism. Experiments with the recombinant E. coli have provided insights into ways to improve 1,3-PD production in both the recombinant and native organism and to modify the pathway for the production of compounds such as 3-hydroxypropionaldehyde and dihydroxyacetone.

  16. Performance evaluation of a continuous-flow bioanode microbial electrolysis cell fed with furanic and phenolic compounds

    SciTech Connect

    Zeng, Xiaofei; Borole, Abhijeet P.; Pavlostathis, Spyros G.

    2016-07-04

    Furanic and phenolic compounds, formed during the pretreatment of lignocellulosic biomass, are problematic byproducts in down-stream biofuel processes. A microbial electrolysis cell (MEC) is an alternative technology to handle furanic and phenolic compounds and produce renewable hydrogen (H2). In this study, we evaluated the performance of a continuous-flow bioanode MEC fed with furanic and phenolic compounds at different operating conditions. All hydraulic retention times (HRTs) tested (6-24 h) resulted in complete transformation of the parent compounds at an organic loading rate (OLR) of 0.2g L-1 per d and applied voltage of 0.6 V. Increasing the OLR to 0.8 g L-1 per d at an HRT of 6h resulted in an increased H2 production rate from 0.07 to 0.14 L Lanode 1 per d, but an OLR of 3.2 g L-1 per d did not lead to a higher H2 production rate. Significant methane production was observed at an OLR of 3.2 g L-1 per d. The lack of increased H2 production at the highest OLR tested was due to a limited rate of exoelectrogenesis but not fermentation, evidenced by the accumulation of high acetate levels and higher growth of fermenters and methanogens over exoelectrogens. Increasing applied voltage from 0.6 to 1.0V at an OLR of 3.2 g L-1 per d and HRT of 6h enhanced exoelectrogenesis and resulted in a 1.7-fold increase of H2 production. Under all operating conditions, more than 90% of the biomass was biofilm-associated. Lastly, the present study provides new insights into the performance of continuous-flow bioelectrochemical systems fed with complex waste streams resulting from the pretreatment of lignocellulosic biomass.

  17. [Effectiveness and difficulty of education on nosocomial infection control for pre-clinical practice in the clinic, so-called inclusive clinical practice phase I, for students in the Faculty of Dentistry, Tokyo Medical and Dental University].

    PubMed

    Sunakawa, Mitsuhiro; Matsumoto, Hiroyuki

    2009-03-01

    It has been planned to give pre-clinical practice in the clinic, so-called inclusive clinical practice phase I, for fifth-grade students in the School of Dentistry, Faculty of Dentistry, Tokyo Medical and Dental University, to give them the clinical training needed to perform dental practice and clinical practicum for comprehensive patient care, namely inclusive clinical practice phase II. This study analyzed the educative efficiency of the class on nosocomial infection control (NIC) by comparing achievements pre- and post-test, and discussed appropriate education planning on the NIC for dental students. Sixty-two fifth-grade students in the 2007 academic year sat the pre- and post-tests; the mean score and standard deviation of these tests were 5.30 +/- 1.26 (n = 56) and 8.59 +/- 1.18 (n = 59), respectively. There was a statistically significant difference between them (paired t-test, p < 0.01). Another finding was that students with high scores in the post-test did not necessarily achieve high ratings in the pre-test. It is suggested that the introduction of pre- and post-tests and the clarification of main points in the class as a theme of NIC could be a useful tool for increasing the comprehension of students on the theme. Since students at lower grades will attend clinical practice in the university hospital, it is thought that students should be given NIC training early in the clinical course, and the current curriculum should be improved to increase the opportunity for students to study this important issue.

  18. Inhibition of microbial growth by ajoene, a sulfur-containing compound derived from garlic.

    PubMed Central

    Naganawa, R; Iwata, N; Ishikawa, K; Fukuda, H; Fujino, T; Suzuki, A

    1996-01-01

    Ajoene, a garlic-derived sulfur-containing compound that prevents platelet aggregation, exhibited broad-spectrum antimicrobial activity. Growth of gram-positive bacteria, such as Bacillus cereus, Bacillus subtilis, Mycobacterium smegmatis, and Streptomyces griseus, was inhibited at 5 micrograms of ajoene per ml. Staphylococcus aureus and Lactobacillus plantarum also were inhibited below 20 micrograms of ajoene per ml. For gram-negative bacteria, such as Escherichia coli, Klebsiella pneumoniae, and Xanthomonas maltophilia, MICs were between 100 and 160 micrograms/ml. Ajoene also inhibited yeast growth at concentrations below 20 micrograms/ml. The microbicidal effect of ajoene on growing cells was observed at slightly higher concentrations than the corresponding MICs. B. cereus and Saccharomyces cerevisiae were killed at 30 micrograms of ajoene per ml after 24 h of cultivation when cultivation was started at 10(5) cells per ml. However, the minimal microbicidal concentrations for resting cells were at 10 to 100 times higher concentrations than the corresponding MICs. The disulfide bond in ajoene appears to be necessary for the antimicrobial activity of ajoene, since reduction by cysteine, which reacts with disulfide bonds, abolished its antimicrobial activity. PMID:8900018

  19. Bioactive compounds produced by gut microbial tannase: implications for colorectal cancer development.

    PubMed

    López de Felipe, Félix; de Las Rivas, Blanca; Muñoz, Rosario

    2014-01-01

    The microorganisms in the human gastrointestinal tract have a profound influence on the transformation of food into metabolites which can impact human health. Gallic acid (GA) and pyrogallol (PG) are bioactive compounds displaying diverse biological properties, including carcinogenic inhibiting activities. However, its concentration in fruits and vegetables is generally low. These metabolites can be also generated as final products of tannin metabolism by microbes endowed with tannase, which opens up the possibility of their anti-cancer potential being increased. Patients with colorectal cancer (CRC) display an imbalanced gut microbiota respect to healthy population. The recent use of next generation sequencing technologies has greatly improved knowledge of the identity of bacterial species that colonize non-tumorous and tumorous tissues of CRC patients. This information provides a unique opportunity to shed light on the role played by gut microorganisms in the different stages of this disease. We here review the recently published gut microbiome associated to CRC patients and highlight tannase as an underlying gene function of bacterial species that selectively colonize tumorous tissues, but not adjacent non-malignant tissues. Given the anti-carcinogenic roles of GA and PG produced by gut tannin-degrading bacteria, we provide an overview of the possible consequences of this intriguing coincidence for CRC development.

  20. In situ stimulation vs. bioaugmentation: Can microbial inoculation of plant roots enhance biodegradation of organic compounds?

    SciTech Connect

    Kingsley, M.T.; Metting, F.B. Jr.; Fredrickson, J.K.; Seidler, R.J.

    1993-06-01

    The use of plant roots and their associated rhizosphere bacteria for biocontainment and biorestoration offers several advantages for treating soil-dispersed contaminants and for application to large land areas. Plant roots function as effective delivery systems, since root growth transports bacteria vertically and laterally along the root in the soil column (see [ 1,2]). Movement of microbes along roots and downward in the soil column can be enhanced via irrigation [1-4]. For example, Ciafardini et al. [3] increased the nodulation and the final yield of soybeans during pod filling by including Bradyrhizobium japonicum in the irrigation water. Using rhizosphere microorganisms is advantageous for biodegradation of compounds that are degraded mainly by cometabolic processes, e.g., trichloroethylene (TCE). The energy source for bacterial growth and metabolism is supplied by the plant in the form of root exudates and other sloughed organic material. Plants are inexpensive, and by careful choice of species that possess either tap or fibrous root growth patterns, they can be used to influence mass transport of soil contaminants to the root surface via the transpiration stream [5]. Cropping of plants to remove heavy metals from contaminated soils has been proposed as a viable, low-cost, low-input treatment option [6]. The interest in use of plants as a remediation strategy has even reached the popular press [7], where the use of ragweed for the reclamation of sites contaminated with tetraethyl lead and other heavy metals was discussed.

  1. Sorption of organic compounds to microbial extracellular polymers: Potential vector for bioaccumulation of sediment-associated contaminants

    SciTech Connect

    Schlekat, C.E.; Decho, A.W.; Chandler, G.T.

    1995-12-31

    Microbial extracellular polymeric substances (EPS) in the form of organic carbon coatings are ubiquitous features of marine surficial sediments and suspended particulate matter. Consisting primarily of polysaccharides, EPS are produced by bacteria for adhesion to substrata, to bind essential nutrients, and to protect bacterial cells from exogenous stressors, including toxic trace metals. EPS particulate coatings are easily digested by marine particle-ingesting invertebrates. Additionally, these organisms directly assimilate dissolved organic material and trace metals adsorbed to EPS-coated particulate. The capacity of EPS-coated particulate matter to serve as a vector for bioaccumulation of sediment-associated contaminants has not been addressed. As a step, the authors measured adsorption of selected organic contaminants by EPS-coated hydrated silica particles (mean diameter = 30 {micro}m). Radio-labeled organic contaminants, including benzo(a)pyrene, hexachlorobiphenyl, and the pesticides azinphosmethyl and chlorpyrifos were associated with coated particles in seawater under constant pH, salinity, temperature, and Eh. Mixtures were incubated until equilibrium was approximated, at which point partitioning between seawater and particulate was determined for each particulate/contaminant combination. The organic compounds exhibited a range of log K{sub ow} from 2.6 (azinphosmethyl) to 6.7 (hexachlorobiphenyl), which allowed for quantification of the relationship between partitioning and contaminant hydrophobicity. Effects of differential EPS composition were evaluated by measuring binding affinity of hexachlorobiphenyl particles coated with EPS obtained from three bacterial species which produce EPS with unique compositional attributes: Azotobacter vinelandii, Leuconostoc mesenteroides, and Pseudomonas atlantica.

  2. Pellitorine, a potential anti-cancer lead compound against HL6 and MCT-7 cell lines and microbial transformation of piperine from Piper Nigrum.

    PubMed

    Ee, Gwendoline Cheng Lian; Lim, Chyi Meei; Rahmani, Mawardi; Shaari, Khozirah; Bong, Choon Fah Joseph

    2010-04-05

    Pellitorine (1), which was isolated from the roots of Piper nigrum, showed strong cytotoxic activities against HL60 and MCT-7 cell lines. Microbial transformation of piperine (2) gave a new compound 5-[3,4-(methylenedioxy)phenyl]-pent-2-ene piperidine (3). Two other alkaloids were also found from Piper nigrum. They are (E)-1-[3',4'-(methylenedioxy)cinnamoyl]piperidine (4) and 2,4-tetradecadienoic acid isobutyl amide (5). These compounds were isolated using chromatographic methods and their structures were elucidated using MS, IR and NMR techniques.

  3. Characterization of Crew Refuse Returned from Shuttle Missions with Permanent Gas, Volatile Organic Compound, and Microbial Analyses

    NASA Astrophysics Data System (ADS)

    Peterson, B.; Hummerick, M.; Roberts, M.; Krummins, V.; Kish, A.; Garland, J.; Maxwell, S.; Mills, A.

    In addition to the mass and energy costs associated with bioregenerative systems for advanced life support, the storage and processing of waste on spacecraft requires both atmospheric and biological management. Risks to crew health may arise from the presence of potential human pathogens in waste or from decay processes during waste storage and/or processing. This study reports on the permanent gas, trace volatile organic and microbiological analyses of crew refuse returned from shuttle missions STS-105, 109 and 110. The research objective is to characterize the biological stability of the waste stream, to assess the risks associated with its storage, and to provide baseline measures for the evaluation of waste processing technologies. Microbiological samples were collected from packaging material, food waste, bathroom waste, and bulk liquid collected from the volume F waste container. The number of culturable bacteria and total bacteria were determined by plating on R2A media and by Acridine Orange direct count, respectively. Samples of the trash were analyzed for the presence of fecal and total coliforms and other human-associated bacteria. Dry and ash weights were determined to estimate both water and organic content of the materials. The aerobic and anaerobic bio-stability of stored waste was determined by on-line monitoring of CO2 and by laboratory analysis of off-gas samples for hydrogen sulfide and methane. Volatile organic compounds and permanent gases were analyzed using EPA method TO15 with gas chromatography/mass spectrometry and by gas chromatography with selective detectors . This study establishes a baseline measure of waste composition, labile organics, and microbial load for this material.

  4. Identification of chlorinated solvents degradation zones in clay till by high resolution chemical, microbial and compound specific isotope analysis.

    PubMed

    Damgaard, Ida; Bjerg, Poul L; Bælum, Jacob; Scheutz, Charlotte; Hunkeler, Daniel; Jacobsen, Carsten S; Tuxen, Nina; Broholm, Mette M

    2013-03-01

    The degradation of chlorinated ethenes and ethanes in clay till was investigated at a contaminated site (Vadsby, Denmark) by high resolution sampling of intact cores combined with groundwater sampling. Over decades of contamination, bioactive zones with degradation of trichloroethene (TCE) and 1,1,1-trichloroethane (1,1,1-TCA) to 1,2-cis-dichloroethene (cis-DCE) and 1,1-dichloroethane, respectively, had developed in most of the clay till matrix. Dehalobacter dominated over Dehalococcoides (Dhc) in the clay till matrix corresponding with stagnation of sequential dechlorination at cis-DCE. Sporadically distributed bioactive zones with partial degradation to ethene were identified in the clay till matrix (thickness from 0.10 to 0.22 m). In one sub-section profile the presence of Dhc with the vcrA gene supported the occurrence of degradation of cis-DCE and VC, and in another enriched δ(13)C for TCE, cis-DCE and VC documented degradation. Highly enriched δ(13)C for 1,1,1-TCA (25‰) and cis-DCE (-4‰) suggested the occurrence of abiotic degradation in a third sub-section profile. Due to fine scale heterogeneity the identification of active degradation zones in the clay till matrix depended on high resolution subsampling of the clay till cores. The study demonstrates that an integrated approach combining chemical analysis, molecular microbial tools and compound specific isotope analysis (CSIA) was required in order to document biotic and abiotic degradations in the clay till system.

  5. Effect of Plants Containing Secondary Compounds with Palm Oil on Feed Intake, Digestibility, Microbial Protein Synthesis and Microbial Population in Dairy Cows

    PubMed Central

    Anantasook, N.; Wanapat, M.; Cherdthong, A.; Gunun, P.

    2013-01-01

    The objective of this study was to determine the effect of rain tree pod meal with palm oil supplementation on feed intake, digestibility, microbial protein synthesis and microbial populations in dairy cows. Four, multiparous early-lactation Holstein-Friesian crossbred (75%) lactating dairy cows with an initial body weight (BW) of 405±40 kg and 36±8 DIM were randomly assigned to receive dietary treatments according to a 4×4 Latin square design. The four dietary treatments were un-supplementation (control), supplementation with rain tree pod meal (RPM) at 60 g/kg, supplementation with palm oil (PO) at 20 g/kg, and supplementation with RPM at 60 g/kg and PO at 20 g/kg (RPO), of total dry matter intake. The cows were offered concentrates, at a ratio of concentrate to milk production of 1:2, and chopped 30 g/kg of urea treated rice straw was fed ad libitum. The RPM contained condensed tannins and crude saponins at 88 and 141 g/kg of DM, respectively. It was found that supplementation with RPM and/or PO to dairy cows diets did not show negative effects on feed intake and ruminal pH and BUN at any times of sampling (p>0.05). However, RPM supplementation resulted in lower crude protein digestibility, NH3-N concentration and number of proteolytic bacteria. It resulted in greater allantoin absorption and microbial crude protein (p<0.05). In addition, dairy cows showed a higher efficiency of microbial N supply (EMNS) in both RPM and RPO treatments. Moreover, NDF digestibility and cellulolytic bacteria numbers were highest in RPO supplementation (p<0.05) while, supplementation with RPM and/or PO decreased the protozoa population in dairy cows. Based on this study, supplementation with RPM and/or PO in diets could improve fiber digestibility, microbial protein synthesis in terms of quantity and efficiency and microbial populations in dairy cows. PMID:25049855

  6. Fabrication of a microbial biosensor based on QD-MWNT supports by a one-step radiation reaction and detection of phenolic compounds in red wines.

    PubMed

    Kim, Seul-Ki; Kwen, Hai-Doo; Choi, Seong-Ho

    2011-01-01

    An Acaligense sp.-immobilized biosensor was fabricated based on QD-MWNT composites as an electron transfer mediator and a microbe immobilization support by a one-step radiation reaction and used for sensing phenolic compounds in commercial red wines. First, a quantum dot-modified multi-wall carbon nanotube (QD-MWNT) composite was prepared in the presence of MWNT by a one-step radiation reaction in an aqueous solution at room temperature. The successful preparation of the QD-MWNT composite was confirmed by XPS, TEM, and elemental analysis. Second, the microbial biosensor was fabricated by immobilization of Acaligense sp. on the surface of the composite thin film of a glassy carbon (GC) electrode, which was prepared by a hand casting method with a mixture of the previously obtained composite and Nafion solution. The sensing ranges of the microbial biosensor based on CdS-MWNT and Cu(2)S-MWNT supports were 0.5-5.0 mM and 0.7-10 mM for phenol in a phosphate buffer solution, respectively. Total concentration of phenolic compounds contained in commercial red wines was also determined using the prepared microbial immobilized biosensor.

  7. Compound

    NASA Astrophysics Data System (ADS)

    Suzumura, Akitoshi; Watanabe, Masaki; Nagasako, Naoyuki; Asahi, Ryoji

    2014-06-01

    Recently, Cu-based chalcogenides such as Cu3SbSe4, Cu2Se, and Cu2SnSe3 have attracted much attention because of their high thermoelectric performance and their common feature of very low thermal conductivity. However, for practical use, materials without toxic elements such as selenium are preferable. In this paper, we report Se-free Cu3SbS4 thermoelectric material and improvement of its figure of merit ( ZT) by chemical substitutions. Substitutions of 3 at.% Ag for Cu and 2 at.% Ge for Sb lead to significant reductions in the thermal conductivity by 37% and 22%, respectively. These substitutions do not sacrifice the power factor, thus resulting in enhancement of the ZT value. The sensitivity of the thermal conductivity to chemical substitutions in these compounds is discussed in terms of the calculated phonon dispersion and previously proposed models for Cu-based chalcogenides. To improve the power factor, we optimize the hole carrier concentration by substitution of Ge for Sb, achieving a power factor of 16 μW/cm K2 at 573 K, which is better than the best reported for Se-based Cu3SbSe4 compounds.

  8. Preliminary assessment of microbial communities and biodegradation of chlorinated volatile organic compounds in wetlands at Cluster 13, Lauderick Creek area, Aberdeen Proving Ground, Maryland

    USGS Publications Warehouse

    Lorah, Michelle M.; Voytek, Mary A.; Spencer, Tracey A.

    2003-01-01

    A preliminary assessment of the microbial communities and biodegradation processes for chlorinated volatile organic compounds was con-ducted by the U.S. Geological Survey in wetlands at the Cluster 13, Lauderick Creek area at Aberdeen Proving Ground, Maryland. The U.S. Geological Survey collected wetland sediment samples from 11 sites in the Lauderick Creek area for microbial analyses, and used existing data to evaluate biodegradation processes and rates. The bacterial and methanogen communities in the Lauderick Creek wetland sediments were similar to those observed in a previous U.S. Geological Survey study at the West Branch Canal Creek wet-land area, Aberdeen Proving Ground. Evaluation of the degradation rate of 1,1,2,2-tetrachloroethane and the daughter compounds produced also showed similar results for the two wetlands. How-ever, a vertical profile of contaminant concentra-tions in the wetlands was available at only one site in the Lauderick Creek area, and flow velocities in the wetland sediment are unknown. To better evaluate natural attenuation processes and rates in the wetland sediments at Lauderick Creek, chemi-cal and hydrologic measurements are needed along ground-water flowpaths in the wetland at additional sites and during different seasons. Nat-ural attenuation in the wetlands, enhanced biore-mediation, and constructed wetlands could be feasible remediation methods for the chlorinated volatile organic compounds discharging in the Lauderick Creek area. The similarities in the microbial communities and biodegradation pro-cesses at the Lauderick Creek and West Branch Canal Creek areas indicate that enhanced bioreme-diation techniques currently being developed for the West Branch Canal Creek wetland area would be transferable to this area.

  9. Single-walled carbon nanotube release affects the microbial enzyme-catalyzed oxidation processes of organic pollutants and lignin model compounds in nature.

    PubMed

    Chen, Ming; Qin, Xiaosheng; Zeng, Guangming

    2016-11-01

    The question how microbial enzyme-catalyzed oxidation processes of organic pollutants and lignin model compounds (LMCs) are affected by the release of single-walled carbon nanotube (SWCNT) into the environment remains to be addressed at the molecular level. We have, therefore concentrated the effects of SWCNT on some important properties associated with enzyme activity and function during microbial oxidation of polycyclic aromatic hydrocarbons (benzo(a)pyrene, acenaphthene and anthracene), LMCs (2,6-dimethoxyphenol, guaiacol and veratryl alcohol) and β-hexachlorocyclohexane, including the behaviour of water molecules, hydrogen bonds (HBs) and hydrophobic interactions (HYs) between ligand and the enzyme, and conformational dynamics in N- and C-terminus. Our study revealed that SWCNT significantly affected the behaviour of water molecules within 5 Å of both these substrates and their respective enzymes during oxidation (p < 0.01), by increasing or decreasing the water number near them. SWCNT tended to significantly enhance or reduce the stability of atom pairs that formed the HBs and HYs (p < 0.01). N- and C-terminus conformations underwent transitions between positive and negative states or between positive state or between negative state in all analyzed complexes. Significant conformational transitions were found for all C-terminus, but only for a part of N-terminus after the inclusion of the SWCNT. These results showed that SWCNT release would significantly affect the microbial enzyme-catalyzed processes of organic pollutants and LMCs in nature.

  10. The impact of yeast starter cultures on the microbial communities and volatile compounds in cocoa fermentation and the resulting sensory attributes of chocolate.

    PubMed

    Batista, Nádia Nara; Ramos, Cíntia Lacerda; Dias, Disney Ribeiro; Pinheiro, Ana Carla Marques; Schwan, Rosane Freitas

    2016-02-01

    Theobroma cacao seeds are the main raw material for chocolate production. During their fermentation, a succession of microorganisms are responsible for the physicochemical changes occurring in the pulp and inside the beans. The aim of this study was to investigate the effects of yeast inoculation (Saccharomyces cerevisiae UFLA CA11, Pichia kluivery CCMA0237, and Hanseniaspora uvarum CCMA0236) on the profile of the volatile compounds and microbial communities in cocoa fermentation. The resulting chocolate was also evaluated by temporal dominance of sensations (TDS) analyses. The dominant microorganisms during spontaneous fermentation were S. cerevisiae, H. uvarum, H. guilliermondii, Lactobacillus fermentum, Pediococcus sp., and Acetobacter pasteurianus. Similarly, S. cerevisiae, P. kluyveri, Candida sp., Pediococcus sp., and A. pasteurianus were the predominant microorganisms assessed by Denaturing Gradient Gel Electrophoresis (DGGE) in inoculated fermentation. Sixty-seven volatile compounds were detected and quantified by gas chromatography/mass spectrometry (GC/MS) at the end of fermentation and chocolates. The main group of volatile compound found after the inoculated and spontaneous fermentations was esters (41 and 39 %, respectively). In the chocolates, the main group was acids (73 and 44 % from the inoculated and spontaneous fermentations, respectively). The TDS analyses showed a dominance of bitter and cocoa attributes in both chocolates. However, in the inoculated chocolate, lingering fruity notes were more intense, while the chocolate produced by spontaneous fermentation was more astringent. Thus, the inoculation of yeast influenced the microbial profile, which likely affected the volatile compounds that affect sensory characteristics, resulting in chocolate with dominant bitter, cocoa, and fruity attributes.

  11. A yearly spraying of olive mill wastewater on agricultural soil over six successive years: impact of different application rates on olive production, phenolic compounds, phytotoxicity and microbial counts.

    PubMed

    Magdich, Salwa; Jarboui, Raja; Rouina, Béchir Ben; Boukhris, Makki; Ammar, Emna

    2012-07-15

    Olive mill wastewater (OMW) spraying effects onto olive-tree fields were investigated. Three OMW levels (50, 100 and 200 m(3)ha(-1)year(-1)) were applied over six successive years. Olive-crop yields, phenolic compounds progress, phytotoxicity and microbial counts were studied at different soil depths. Olive yield showed improvements with OMW level applied. Soil polyphenolic content increased progressively in relation to OMW levels in all the investigated layers. However, no significant difference was noted in lowest treatment rate compared to the control field. In the soil upper-layers (0-40 cm), five phenolic compounds were identified over six consecutive years of OMW-spraying. In all the soil-layers, the radish germination index exceeded 85%. However, tomato germination test values decreased with the applied OMW amount. For all treatments, microbial counts increased with OMW quantities and spraying frequency. Matrix correlation showed a strong relationship between soil polyphenol content and microorganisms, and a negative one to tomato germination index.

  12. Bioremediation of PAH-contamined soils: Consequences on formation and degradation of polar-polycyclic aromatic compounds and microbial community abundance.

    PubMed

    Biache, Coralie; Ouali, Salma; Cébron, Aurélie; Lorgeoux, Catherine; Colombano, Stéfan; Faure, Pierre

    2017-05-05

    A bioslurry batch experiment was carried out over five months on three polycyclic aromatic compound (PAC) contaminated soils to study the PAC (PAH and polar-PAC) behavior during soil incubation and to evaluate the impact of PAC contamination on the abundance of microbial communities and functional PAH-degrading populations. Organic matter characteristics and reactivity, assessed through solvent extractable organic matter and PAC contents, and soil organic matter mineralization were monitored during 5 months. Total bacteria and fungi, and PAH-ring hydroxylating dioxygenase genes were quantified. Results showed that PAHs and polar-PACs were degraded with different degradation dynamics. Differences in degradation rates were observed among the three soils depending on PAH distribution and availability. Overall, low molecular weight compounds were preferentially degraded. Degradation selectivity between isomers and structurally similar compounds was observed which could be used to check the efficiency of bioremediation processes. Bacterial communities were dominant over fungi and were most likely responsible for PAC degradation. Abundance of PAH-degrading bacteria increased during incubations, but their proportion in the bacterial communities tended to decrease. The accumulation of some oxygenated-PACs during the bioslurry experiment underlines the necessity to monitor these compounds during application of remediation treatment on PAH contaminated soils.

  13. Rapid evaluation technique to differentiate mushroom disease-related moulds by detecting microbial volatile organic compounds using HS-SPME-GC-MS.

    PubMed

    Radványi, Dalma; Gere, Attila; Jókai, Zsuzsa; Fodor, Péter

    2015-01-01

    Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) was used to analyse microbial volatile organic compounds (MVOCs) of mushroom disease-related microorganisms. Mycogone perniciosa, Lecanicillum fungicola var. fungicola, and Trichoderma aggressivum f. europaeum species, which are typically harmful in mushroom cultivation, were examined, and Agaricus bisporus (bisporic button mushroom) was also examined as a control. For internal standard, a mixture of alkanes was used; these were introduced as the memory effect of primed septa in the vial seal. Several different marker compounds were found in each sample, which enabled us to distinguish the different moulds and the mushroom mycelium from each other. Monitoring of marker compounds enabled us to investigate the behaviour of moulds. The records of the temporal pattern changes were used to produce partial least squares regression (PLS-R) models that enabled determination of the exact time of contamination (the infection time of the media). Using these evaluation techniques, the presence of mushroom disease-related fungi can be easily detected and monitored via their emitted MVOCs.

  14. Microbial transformation of bioactive compounds and production of ortho-dihydroxyisoflavones and glycitein from natural fermented soybean paste.

    PubMed

    Roh, Changhyun

    2014-12-12

    Recently, there has been a great deal of remarkable interest in finding bioactive compounds from nutritional foods to replace synthetic compounds. In particular, ortho-dihydroxyisoflavones and glycitein are of growing scientific interest owing to their attractive biological properties. In this study, 7,8-ortho-dihydroxyisoflavone, 6,7-ortho-dihydroxyisoflavone, 3',4'-ortho-dihydroxyisoflavone and 7,4'-dihydroxy-6-methoxyisoflavone were characterized using microorganism screened from soybean Doenjang. Three ortho-dihydroxyisoflavones and glycitein were structurally elucidated by 1H-NMR and GC-MS analysis. Furthermore, bacterial strains from soybean Doenjang with the capacity of biotransformation were screened. The bacterial strain, identified as Bacillus subtilis Roh-1, was shown to convert daidzein into ortho-dihydroxyisoflavones and glycitein. Thus, this study has, for the first time, demonstrated that a bacterial strain had a substrate specificity for multiple modifications of the bioactive compounds.

  15. Compound-specific 15N stable isotope probing of N assimilation by the soil microbial biomass: a new methodological paradigm in soil N cycling

    NASA Astrophysics Data System (ADS)

    Charteris, A. F.; Knowles, T. D. J.; Michaelides, K.; Evershed, R. P.

    2015-10-01

    A compound-specific nitrogen-15 stable isotope probing (15N-SIP) technique is described which allows investigation of the fate of inorganic- or organic-N amendments to soils. The technique uses gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) to determine the δ15N values of individual amino acids (AAs; determined as N-acetyl, O-isopropyl derivatives) as proxies of biomass protein production. The δ15N values are used together with AA concentrations to quantify N assimilation of 15N-labelled substrates by the soil microbial biomass. The utility of the approach is demonstrated through incubation experiments using inorganic 15N-labelled substrates ammonium (15NH4+) and nitrate (15NO3-) and an organic 15N-labelled substrate, glutamic acid (15N-Glu). Assimilation of all the applied substrates was undetectable based on bulk soil properties, i.e. % total N (% TN), bulk soil N isotope composition and AA concentrations, all of which remained relatively constant throughout the incubation experiments. In contrast, compound-specific AA δ15N values were highly sensitive to N assimilation, providing qualitative and quantitative insights into the cycling and fate of the applied 15N-labelled substrates. The utility of this 15N-AA-SIP technique is considered in relation to other currently available methods for investigating the microbially-mediated assimilation of nitrogenous substrates into the soil organic N pool. This approach will be generally applicable to the study of N cycling in any soil, or indeed, in any complex ecosystem.

  16. Screening of microbial volatile organic compounds for detection of disease in cattle: development of lab-scale method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The quest to find unique marker volatile organic compounds (VOCs) associated with human, livestock and wildlife diseases (Ellis et al., 2014) requires development of diagnostic non-invasive point-of-care tools and field surveillance technologies and strategies. The objective of this research was to ...

  17. [So-called antiphospholipid antibodies and infertility: biological data].

    PubMed

    de Maistre, E

    2003-09-01

    Recurrent early and late foetal losses are common problems found in women with antiphospholipid syndrome, with therapeutic implication and improvement of the prognosis for the next pregnancies with antithrombotic therapy. After these results, some groups propose to extend the antiphospholipid investigations to infertility and failure of in vitro fertilization embryo transfer, but actually without demonstration of a real utility in the management of these women.

  18. Basilar impression and the so-called 'associated anomalies'.

    PubMed

    Bares, L

    1975-01-01

    Analysing the casuistry of 210 patients with basilar impression, the author has enumerated the type and frequency of the associated anomalies and looked for correlations between them and the various clinical syndromes. An attempt is made to divide the anomalies into pathogenetic groups on the basis of these findings.

  19. [So-called "spontaneous" lesions of the popliteal artery].

    PubMed

    Miani, S; De Monti, M; Boneschi, M; Giordanengo, F

    1997-11-01

    The term "spontaneous", when attributed to a stenotic or obliterative arterial lesion, could seem ambiguous and doesn't completely explain the anatomical substrate that is the basis of this morbid condition. However, it is true that injuries can occur without the patient being aware of any traumatic event, and can cause a symptomatology arising suddenly and, apparently, "spontaneously". In this study, three cases of patients observed for acute or chronic lower limb ischemia are presented. All patients were male, young and underwent an angiographic examination that demonstrated, in an otherwise normal arterial tree, filling defects or obstruction involving the popliteal artery. Two patients underwent a reconstructive surgical procedure. The third was medically treated. CAT or MNR examinations were performed in order to exclude developmental defect such as an anomalous course of popliteal artery determined by a displacement due to medial head of the gastrocnemius muscle. Actually in these three cases, a definite etiology of the arterial damage was not demonstrated and therefore it is suggested that a physical effort could have injured an already weakened arterial structure.

  20. Communicating with the So-Called Monster Media.

    ERIC Educational Resources Information Center

    Bohen, Dolores Boylston

    1998-01-01

    The public interest is best served when articulate, credible school leaders and spokespersons work closely with responsible, knowledgeable journalists. Schools cannot forge productive relationships by disdaining or stonewalling the media. People have become cynical about the public engagement process. Blaming the press diverts energy from real…

  1. Detection of volatile compounds produced by microbial growth in urine by selected ion flow tube mass spectrometry (SIFT-MS).

    PubMed

    Storer, Malina K; Hibbard-Melles, Kim; Davis, Brett; Scotter, Jenny

    2011-10-01

    Selected ion flow tube-mass spectrometry has been used to measure the volatile compounds occurring in the headspace of urine samples inoculated with common urinary tract infection (UTI)-causing microbes Escherichia coli, Proteus vulgaris, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, Enterococcus faecalis, or Candida albicans. This technique has the potential to offer rapid and simple diagnosis of the causative agent of UTIs.

  2. Quantifying the Importance of the Rare Biosphere for Microbial Community Response to Organic Pollutants in a Freshwater Ecosystem.

    PubMed

    Wang, Yuanqi; Hatt, Janet K; Tsementzi, Despina; Rodriguez-R, Luis M; Ruiz-Pérez, Carlos A; Weigand, Michael R; Kizer, Heidi; Maresca, Gina; Krishnan, Raj; Poretsky, Rachel; Spain, Jim C; Konstantinidis, Konstantinos T

    2017-04-15

    A single liter of water contains hundreds, if not thousands, of bacterial and archaeal species, each of which typically makes up a very small fraction of the total microbial community (<0.1%), the so-called "rare biosphere." How often, and via what mechanisms, e.g., clonal amplification versus horizontal gene transfer, the rare taxa and genes contribute to microbial community response to environmental perturbations represent important unanswered questions toward better understanding the value and modeling of microbial diversity. We tested whether rare species frequently responded to changing environmental conditions by establishing 20-liter planktonic mesocosms with water from Lake Lanier (Georgia, USA) and perturbing them with organic compounds that are rarely detected in the lake, including 2,4-dichlorophenoxyacetic acid (2,4-D), 4-nitrophenol (4-NP), and caffeine. The populations of the degraders of these compounds were initially below the detection limit of quantitative PCR (qPCR) or metagenomic sequencing methods, but they increased substantially in abundance after perturbation. Sequencing of several degraders (isolates) and time-series metagenomic data sets revealed distinct cooccurring alleles of degradation genes, frequently carried on transmissible plasmids, especially for the 2,4-D mesocosms, and distinct species dominating the post-enrichment microbial communities from each replicated mesocosm. This diversity of species and genes also underlies distinct degradation profiles among replicated mesocosms. Collectively, these results supported the hypothesis that the rare biosphere can serve as a genetic reservoir, which can be frequently missed by metagenomics but enables community response to changing environmental conditions caused by organic pollutants, and they provided insights into the size of the pool of rare genes and species.IMPORTANCE A single liter of water or gram of soil contains hundreds of low-abundance bacterial and archaeal species, the so

  3. Optimization of headspace solid phase microextraction for the analysis of microbial volatile organic compounds emitted by fungi: Application to historical objects.

    PubMed

    Sawoszczuk, Tomasz; Syguła-Cholewińska, Justyna; del Hoyo-Meléndez, Julio M

    2015-08-28

    The main goal of this work was to optimize the SPME sampling method for measuring microbial volatile organic compounds (MVOCs) emitted by active molds that may deteriorate historical objects. A series of artificially aged model materials that resemble those found in historical objects was prepared and evaluated after exposure to four different types of fungi. The investigated pairs consisted of: Alternaria alternata on silk, Aspergillus niger on parchment, Chaetomium globosum on paper and wool, and Cladosporium herbarum on paper. First of all, a selection of the most efficient SPME fibers was carried out as there are six different types of fibers commercially available. It was important to find a fiber that absorbs the biggest number and the highest amount of MVOCs. The results allowed establishing and selecting the DVB/CAR/PDMS fiber as the most effective SPME fiber for this kind of an analysis. Another task was to optimize the time of MVOCs extraction on the fiber. It was recognized that a time between 12 and 24h is adequate for absorbing a high enough amount of MVOCs. In the last step the temperature of MVOCs desorption in the GC injection port was optimized. It was found that desorption at a temperature of 250°C allowed obtaining chromatograms with the highest abundances of compounds. To the best of our knowledge this work constitutes the first attempt of the SPME method optimization for sampling MVOCs emitted by molds growing on historical objects.

  4. Microbially Mediated Biodegradation of Hexahydro-1,3,5-Trinitro-1,3,5- Triazine by Extracellular Electron Shuttling Compounds

    PubMed Central

    Kwon, Man Jae; Finneran, Kevin T.

    2006-01-01

    The potential for humic substances to stimulate the reduction of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was investigated. This study describes a novel approach for the remediation of RDX-contaminated environments using microbially mediated electron shuttling. Incubations without cells demonstrated that reduced AQDS transfers electrons directly to RDX, which was reduced without significant accumulation of the nitroso intermediates. Three times as much reduced AQDS (molar basis) was needed to completely reduce RDX. The rate and extent of RDX reduction differed greatly among electron shuttle/acceptor amendments for resting cell suspensions of Geobacter metallireducens and G. sulfurreducens with acetate as the sole electron donor. AQDS and purified humic substances stimulated the fastest rate of RDX reduction. The nitroso metabolites did not significantly accumulate in the presence of AQDS or humic substances. RDX reduction in the presence of poorly crystalline Fe(III) was relatively slow and metabolites transiently accumulated. However, adding humic substances or AQDS to Fe(III)-containing incubations increased the reduction rates. Cells of G. metallireducens alone reduced RDX; however, the rate of RDX reduction was slow relative to AQDS-amended incubations. These data suggest that extracellular electron shuttle-mediated RDX transformation is not organism specific but rather is catalyzed by multiple Fe(III)- and humic-reducing species. Electron shuttle-mediated RDX reduction may eventually become a rapid and effective cleanup strategy in both Fe(III)-rich and Fe(III)-poor environments. PMID:16957213

  5. Transport of chemical and microbial compounds from known wastewater discharges: Potential for use as indicators of human fecal contamination

    USGS Publications Warehouse

    Glassmeyer, S.T.; Furlong, E.T.; Kolpin, D.W.; Cahill, J.D.; Zaugg, S.D.; Werner, S.L.; Meyer, M.T.; Kryak, D.D.

    2005-01-01

    The quality of drinking and recreational water is currently (2005) determined using indicator bacteria. However, the culture tests used to analyze for these bacteria require a long time to complete and do not discriminate between human and animal fecal material sources. One complementary approach is to use chemicals found in human wastewater, which would have the advantages of (1) potentially shorter analysis times than the bacterial culture tests and (2) being selected for human-source specificity. At 10 locations, water samples were collected upstream and at two successive points downstream from a wastewaster treatment plant (WWTP); a treated effluent sample was also collected at each WWTP. This sampling plan was used to determine the persistence of a chemically diverse suite of emerging contaminants in streams. Samples were also collected at two reference locations assumed to have minimal human impacts. Of the 110 chemical analytes investigated in this project, 78 were detected at least once. The number of compounds in a given sample ranged from 3 at a reference location to 50 in a WWTP effluent sample. The total analyte load at each location varied from 0.018 μg/L at the reference location to 97.7 μg/L in a separate WWTP effluent sample. Although most of the compound concentrations were in the range of 0.01−1.0 μg/L, in some samples, individual concentrations were in the range of 5−38 μg/L. The concentrations of the majority of the chemicals present in the samples generally followed the expected trend:  they were either nonexistent or at trace levels in the upstream samples, had their maximum concentrations in the WWTP effluent samples, and then declined in the two downstream samples. This research suggests that selected chemicals are useful as tracers of human wastewater discharge.

  6. Nanoporous microscale microbial incubators.

    PubMed

    Ge, Zhifei; Girguis, Peter R; Buie, Cullen R

    2016-02-07

    Reconstruction of phylogenetic trees based on 16S rRNA gene sequencing reveals abundant microbial diversity that has not been cultured in the laboratory. Many attribute this so-called 'great plate count anomaly' to traditional microbial cultivation techniques, which largely facilitate the growth of a single species. Yet, it is widely recognized that bacteria in nature exist in complex communities. One technique to increase the pool of cultivated bacterial species is to co-culture multiple species in a simulated natural environment. Here, we present nanoporous microscale microbial incubators (NMMI) that enable high-throughput screening and real-time observation of multi-species co-culture. The key innovation in NMMI is that they facilitate inter-species communication while maintaining physical isolation between species, which is ideal for genomic analysis. Co-culture of a quorum sensing pair demonstrates that the NMMI can be used to culture multiple species in chemical communication while monitoring the growth dynamics of individual species.

  7. Bioavailability of heavy metals in soil: impact on microbial biodegradation of organic compounds and possible improvement strategies.

    PubMed

    Olaniran, Ademola O; Balgobind, Adhika; Pillay, Balakrishna

    2013-05-15

    Co-contamination of the environment with toxic chlorinated organic and heavy metal pollutants is one of the major problems facing industrialized nations today. Heavy metals may inhibit biodegradation of chlorinated organics by interacting with enzymes directly involved in biodegradation or those involved in general metabolism. Predictions of metal toxicity effects on organic pollutant biodegradation in co-contaminated soil and water environments is difficult since heavy metals may be present in a variety of chemical and physical forms. Recent advances in bioremediation of co-contaminated environments have focussed on the use of metal-resistant bacteria (cell and gene bioaugmentation), treatment amendments, clay minerals and chelating agents to reduce bioavailable heavy metal concentrations. Phytoremediation has also shown promise as an emerging alternative clean-up technology for co-contaminated environments. However, despite various investigations, in both aerobic and anaerobic systems, demonstrating that metal toxicity hampers the biodegradation of the organic component, a paucity of information exists in this area of research. Therefore, in this review, we discuss the problems associated with the degradation of chlorinated organics in co-contaminated environments, owing to metal toxicity and shed light on possible improvement strategies for effective bioremediation of sites co-contaminated with chlorinated organic compounds and heavy metals.

  8. Bioavailability of Heavy Metals in Soil: Impact on Microbial Biodegradation of Organic Compounds and Possible Improvement Strategies

    PubMed Central

    Olaniran, Ademola O.; Balgobind, Adhika; Pillay, Balakrishna

    2013-01-01

    Co-contamination of the environment with toxic chlorinated organic and heavy metal pollutants is one of the major problems facing industrialized nations today. Heavy metals may inhibit biodegradation of chlorinated organics by interacting with enzymes directly involved in biodegradation or those involved in general metabolism. Predictions of metal toxicity effects on organic pollutant biodegradation in co-contaminated soil and water environments is difficult since heavy metals may be present in a variety of chemical and physical forms. Recent advances in bioremediation of co-contaminated environments have focussed on the use of metal-resistant bacteria (cell and gene bioaugmentation), treatment amendments, clay minerals and chelating agents to reduce bioavailable heavy metal concentrations. Phytoremediation has also shown promise as an emerging alternative clean-up technology for co-contaminated environments. However, despite various investigations, in both aerobic and anaerobic systems, demonstrating that metal toxicity hampers the biodegradation of the organic component, a paucity of information exists in this area of research. Therefore, in this review, we discuss the problems associated with the degradation of chlorinated organics in co-contaminated environments, owing to metal toxicity and shed light on possible improvement strategies for effective bioremediation of sites co-contaminated with chlorinated organic compounds and heavy metals. PMID:23676353

  9. Mécanismes de génération de bruits telluriques dans la bande ultrabasse fréquence (UBF) : sources possibles des signaux dits «signaux électro-sismiques » (SES)Generation mechanisms of telluric noises in ULF band: possible sources for the so-called 'seismic electric signals' (SES)

    NASA Astrophysics Data System (ADS)

    Pham, Van Ngoc; Boyer, Danièle; Perrier, Frédéric; Le Mouël, Jean-Louis

    2001-09-01

    Some anomalous transient electric signals in the ULF band, the so-called SES, are claimed to be earthquake precursors. However, their origin remains widely unknown. Anomalous signals having the same characteristics as the SES have been observed at the 'Centre de recherche géophysique' (CRG), Garchy (France) and their origin has now been clearly identified with the leakage of electric and phone networks of the CRG. They can be generated by two electrochemical mechanisms of the metallic electrode polarization: the galvanic cell and the AC electrolytic cell. These two mechanisms were controlled by field experiments, and their existence can be generalized and extrapolated to different scales. Any lack of insulation of grounded metallic bodies (underground electric and phone networks, pipelines, gas and water metallic conduits, railways, grounded towers of high power electric lines etc.) could lead to the generation of DC signals looking like the so-called SES. The greatest care must then be taken when claiming the existence of electric precursors of seismic or volcanic significance.

  10. What Plurals and Compounds Reveal about Constraints in Word Formation

    ERIC Educational Resources Information Center

    Jaensch, Carol; Heyer, Vera; Gordon, Peter; Clahsen, Harald

    2014-01-01

    Morphological systems are constrained in how they interact with each other. One case that has been widely studied in the psycholinguistic literature is the avoidance of plurals inside compounds (e.g. *"rats eater" vs. "rat eater") in English and other languages, the so-called "plurals-in-compounds effect." Several…

  11. Methylobacterium Genome Sequences: A Reference Blueprint to Investigate Microbial Metabolism of C1 Compounds from Natural and Industrial Sources

    PubMed Central

    Lee, Ming-Chun; Bringel, Françoise; Lajus, Aurélie; Zhou, Yang; Gourion, Benjamin; Barbe, Valérie; Chang, Jean; Cruveiller, Stéphane; Dossat, Carole; Gillett, Will; Gruffaz, Christelle; Haugen, Eric; Hourcade, Edith; Levy, Ruth; Mangenot, Sophie; Muller, Emilie; Nadalig, Thierry; Pagni, Marco; Penny, Christian; Peyraud, Rémi; Robinson, David G.; Roche, David; Rouy, Zoé; Saenampechek, Channakhone; Salvignol, Grégory; Vallenet, David; Wu, Zaining; Marx, Christopher J.; Vorholt, Julia A.; Olson, Maynard V.; Kaul, Rajinder; Weissenbach, Jean; Médigue, Claudine; Lidstrom, Mary E.

    2009-01-01

    Background Methylotrophy describes the ability of organisms to grow on reduced organic compounds without carbon-carbon bonds. The genomes of two pink-pigmented facultative methylotrophic bacteria of the Alpha-proteobacterial genus Methylobacterium, the reference species Methylobacterium extorquens strain AM1 and the dichloromethane-degrading strain DM4, were compared. Methodology/Principal Findings The 6.88 Mb genome of strain AM1 comprises a 5.51 Mb chromosome, a 1.26 Mb megaplasmid and three plasmids, while the 6.12 Mb genome of strain DM4 features a 5.94 Mb chromosome and two plasmids. The chromosomes are highly syntenic and share a large majority of genes, while plasmids are mostly strain-specific, with the exception of a 130 kb region of the strain AM1 megaplasmid which is syntenic to a chromosomal region of strain DM4. Both genomes contain large sets of insertion elements, many of them strain-specific, suggesting an important potential for genomic plasticity. Most of the genomic determinants associated with methylotrophy are nearly identical, with two exceptions that illustrate the metabolic and genomic versatility of Methylobacterium. A 126 kb dichloromethane utilization (dcm) gene cluster is essential for the ability of strain DM4 to use DCM as the sole carbon and energy source for growth and is unique to strain DM4. The methylamine utilization (mau) gene cluster is only found in strain AM1, indicating that strain DM4 employs an alternative system for growth with methylamine. The dcm and mau clusters represent two of the chromosomal genomic islands (AM1: 28; DM4: 17) that were defined. The mau cluster is flanked by mobile elements, but the dcm cluster disrupts a gene annotated as chelatase and for which we propose the name “island integration determinant” (iid). Conclusion/Significance These two genome sequences provide a platform for intra- and interspecies genomic comparisons in the genus Methylobacterium, and for investigations of the adaptive

  12. In vitro-in vivo study on the effects of plant compounds on rumen fermentation, microbial abundances and methane emissions in goats.

    PubMed

    Martínez-Fernández, G; Abecia, L; Martín-García, A I; Ramos-Morales, E; Hervás, G; Molina-Alcaide, E; Yáñez-Ruiz, D R

    2013-12-01

    Two in vitro and one in vivo experiments were conducted to investigate the effects of a selection of plant compounds on rumen fermentation, microbial concentration and methane emissions in goats. Treatments were: control (no additive), carvacrol (CAR), cinnamaldehyde (CIN), eugenol (EUG), propyl propane thiosulfinate (PTS), propyl propane thiosulfonate (PTSO), diallyl disulfide (DDS), a mixture (40 : 60) of PTS and PTSO (PTS+PTSO), and bromochloromethane (BCM) as positive control with proven antimethanogenic effectiveness. Four doses (40, 80, 160 and 320 µl/l) of the different compounds were incubated in vitro for 24 h in diluted rumen fluid from goats using two diets differing in starch and protein source within the concentrate (Experiment 1).The total gas production was linearly decreased (P<0.012) by all compounds, with the exception of EUG and PTS+PTSO (P≥ 0.366). Total volatile fatty-acid (VFA) concentration decreased (P≤ 0.018) only with PTS, PTSO and CAR, whereas the acetate:propionate ratio decreased (P≤ 0.002) with PTS, PTSO and BCM, and a tendency (P=0.064) was observed for DDS. On the basis of results from Experiment 1, two doses of PTS, CAR, CIN, BCM (160 and 320 µl/l), PTSO (40 and 160 µl/l) and DDS (80 and 320 µl/l) were further tested in vitro for 72 h (Experiment 2). The gas production kinetics were affected (P≤ 0.045) by all compounds, and digested NDF (DNDF) after 72 h of incubation was only linearly decreased (P≤ 0.004) by CAR and PTS. The addition of all compounds linearly decreased (P≤ 0.009) methane production, although the greatest reductions were observed for PTS (up to 96%), DDS (62%) and BCM (95%). No diet-dose interaction was observed. To further test the results obtained in vitro, two groups of 16 adult non-pregnant goats were used to study in vivo the effect of adding PTS (50, 100 and 200 mg/l rumen content per day) and BCM (50, 100 and 160 mg/l rumen content per day) during the 9 days on methane emissions (Experiment 3

  13. A composite microbial agent containing bacterial and fungal species: Optimization of the preparation process, analysis of characteristics, and use in the purification for volatile organic compounds.

    PubMed

    Cheng, Zhuowei; Lu, Lichao; Kennes, Christian; Ye, Jiexu; Yu, Jianming; Chen, Dongzhi; Chen, Jianmeng

    2016-10-01

    Proper preservation of microbial activity over long periods poses a considerable challenge for pollutant biopurification. A composite microbial agent, mainly composed of bacteria and fungi isolated by the current research team, was constructed in this study and its performance in the removal of mixed waste gases (containing α-pinene, n-butyl acetate and o-xylene) was investigated. According to the removal efficiency in the first 24h and the response to starvation, the optimal ratio of selected carriers (activated carbon, wheat bran and sawdust) was found to be 1:2:1. In some cases of storages, the removal capability of the microbial agent was more than twice that of the suspension. Microbial analysis showed that the inoculated bacterial and fungal strains dominated the agent preparation and utilization. These results indicated that the agent has potential for use in biopurification of mixed waste gas, favoring the reduction of environmental passives and longer retention of microbial activity.

  14. Microbial Siderophores

    NASA Astrophysics Data System (ADS)

    Budzikiewicz, Herbert

    Iron is of great importance for many metabolic processes since the redox potential between its two valence states Fe2+ and Fe3+ lies within the range of physiological processes. Actually, iron is not a rare element, it is fourth in abundance in the earth crust, but it is not readily available for microorganisms. In the soil ferric oxide hydrates are formed at pH values around seven and the concentration of free Fe3+ is at best 10-17 mol/dm3 while about 10-6 mol/dm3 would be needed. In living organisms iron is usually strongly bound to peptidic substances such as transferrins. To increase the supply of soluble iron microorganisms other than those living in an acidic habitat may circumvent the problem by reduction of Fe3+ to Fe2+ (182), which seems to be of major importance for marine phytoplankton (151); see also amphiphilic marine bacteria (Sect.2.8) and Fe2+ binding ligands (Sect. 7) below. An important alternative is the production of Fe3+ chelating compounds, so-called siderophores. Siderophores are secondary metabolites with masses below 2,000 Da and a high affinity to Fe3+. Small iron-siderophore complexes can enter the cell via unspecific porins, larger ones need a transport system that recognizes the ferri-siderophore at the cell surface. In the cell, iron is released mostly by reduction to the less strongly bound Fe2+ state (137), and the free siderophore is re-exported ("shuttle mechanism"); for a modified shuttle system see pyoverdins (Sect. 2.1) and amonabactins (Sect. 2.7). Rarely the siderophore is degraded in the periplasmatic space as, e.g. enterobactin (Sect. 2.7). Alternatively Fe3+ is transferred at the cell surface from the ferri-siderophore to a trans-membrane transport system ("taxi mechanism"). A probably archaic and unspecific variety of the taxi mechanism comprises the reduction of Fe3+ at the cell surface (see ferrichrome A, Sect. 2.6 (99, 105)). The terms "shuttle" and "taxi mechanism" were coined by Raymond and Carrano (296).

  15. Application of natural blends of phytochemicals derived from the root exudates of Arabidopsis to the soil reveal that phenolic-related compounds predominantly modulate the soil microbiome.

    PubMed

    Badri, Dayakar V; Chaparro, Jacqueline M; Zhang, Ruifu; Shen, Qirong; Vivanco, Jorge M

    2013-02-15

    The roots of plants have the ability to influence its surrounding microbiology, the so-called rhizosphere microbiome, through the creation of specific chemical niches in the soil mediated by the release of phytochemicals. Here we report how these phytochemicals could modulate the microbial composition of a soil in the absence of the plant. For this purpose, root exudates of Arabidopsis were collected and fractionated to obtain natural blends of phytochemicals at various relative concentrations that were characterized by GC-MS and applied repeatedly to a soil. Soil bacterial changes were monitored by amplifying and pyrosequencing the 16 S ribosomal small subunit region. Our analyses reveal that one phytochemical can culture different operational taxonomic units (OTUs), mixtures of phytochemicals synergistically culture groups of OTUs, and the same phytochemical can act as a stimulator or deterrent to different groups of OTUs. Furthermore, phenolic-related compounds showed positive correlation with a higher number of unique OTUs compared with other groups of compounds (i.e. sugars, sugar alcohols, and amino acids). For instance, salicylic acid showed positive correlations with species of Corynebacterineae, Pseudonocardineae and Streptomycineae, and GABA correlated with species of Sphingomonas, Methylobacterium, Frankineae, Variovorax, Micromonosporineae, and Skermanella. These results imply that phenolic compounds act as specific substrates or signaling molecules for a large group of microbial species in the soil.

  16. Industrial microbial enzymes: their discovery by screening and use in large-scale production of useful chemicals in Japan.

    PubMed

    Ogawa, Jun; Shimizu, Sakayu

    2002-08-01

    The application of microbial enzymes to large-scale organic synthesis is currently attracting much attention, and has been uniquely developed especially in Japan. The discovery of new microbial enzymes through extensive and persistent screening has brought about many new and simple routes for synthetic processes. The application of these enzymes in so-called 'hybrid processes' of enzymatic and chemical reactions, provide one possible way to solve environmental problems.

  17. Middle infrared (wavelength range: 8 μm-14 μm) 2-dimensional spectroscopy (total weight with electrical controller: 1.7 kg, total cost: less than 10,000 USD) so-called hyperspectral camera for unmanned air vehicles like drones

    NASA Astrophysics Data System (ADS)

    Yamamoto, Naoyuki; Saito, Tsubasa; Ogawa, Satoru; Ishimaru, Ichiro

    2016-05-01

    We developed the palm size (optical unit: 73[mm]×102[mm]×66[mm]) and light weight (total weight with electrical controller: 1.7[kg]) middle infrared (wavelength range: 8[μm]-14[μm]) 2-dimensional spectroscopy for UAV (Unmanned Air Vehicle) like drone. And we successfully demonstrated the flights with the developed hyperspectral camera mounted on the multi-copter so-called drone in 15/Sep./2015 at Kagawa prefecture in Japan. We had proposed 2 dimensional imaging type Fourier spectroscopy that was the near-common path temporal phase-shift interferometer. We install the variable phase shifter onto optical Fourier transform plane of infinity corrected imaging optical systems. The variable phase shifter was configured with a movable mirror and a fixed mirror. The movable mirror was actuated by the impact drive piezo-electric device (stroke: 4.5[mm], resolution: 0.01[μm], maker: Technohands Co.,Ltd., type:XDT50-45, price: around 1,000USD). We realized the wavefront division type and near common path interferometry that has strong robustness against mechanical vibrations. Without anti-mechanical vibration systems, the palm-size Fourier spectroscopy was realized. And we were able to utilize the small and low-cost middle infrared camera that was the micro borometer array (un-cooled VOxMicroborometer, pixel array: 336×256, pixel pitch: 17[μm], frame rate 60[Hz], maker: FLIR, type: Quark 336, price: around 5,000USD). And this apparatus was able to be operated by single board computer (Raspberry Pi.). Thus, total cost was less than 10,000 USD. We joined with KAMOME-PJ (Kanagawa Advanced MOdule for Material Evaluation Project) with DRONE FACTORY Corp., KUUSATSU Corp., Fuji Imvac Inc. And we successfully obtained the middle infrared spectroscopic imaging with multi-copter drone.

  18. Effect of stocking large channel catfish in a biofloc technology production system on production and incidence of common microbial off-flavor compounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Density-dependent production and incidence of common microbial off-flavors caused by geosmin and 2-methylisoborneol were investigated in an outdoor biofloc technology production system stocked with stocker-size (217 g/fish) channel catfish at 1.4, 2.1, or 2.8 kg/m3. Individual weight at harvest rang...

  19. The Neuro-endocrinological Role of Microbial Glutamate and GABA Signaling

    PubMed Central

    Mazzoli, Roberto; Pessione, Enrica

    2016-01-01

    Gut microbiota provides the host with multiple functions (e.g., by contributing to food digestion, vitamin supplementation, and defense against pathogenic strains) and interacts with the host organism through both direct contact (e.g., through surface antigens) and soluble molecules, which are produced by the microbial metabolism. The existence of the so-called gut–brain axis of bi-directional communication between the gastrointestinal tract and the central nervous system (CNS) also supports a communication pathway between the gut microbiota and neural circuits of the host, including the CNS. An increasing body of evidence has shown that gut microbiota is able to modulate gut and brain functions, including the mood, cognitive functions, and behavior of humans. Nonetheless, given the extreme complexity of this communication network, its comprehension is still at its early stage. The present contribution will attempt to provide a state-of-the art description of the mechanisms by which gut microbiota can affect the gut–brain axis and the multiple cellular and molecular communication circuits (i.e., neural, immune, and humoral). In this context, special attention will be paid to the microbial strains that produce bioactive compounds and display ascertained or potential probiotic activity. Several neuroactive molecules (e.g., catecholamines, histamine, serotonin, and trace amines) will be considered, with special focus on Glu and GABA circuits, receptors, and signaling. From the basic science viewpoint, “microbial endocrinology” deals with those theories in which neurochemicals, produced by both multicellular organisms and prokaryotes (e.g., serotonin, GABA, glutamate), are considered as a common shared language that enables interkingdom communication. With regards to its application, research in this area opens the way toward the possibility of the future use of neuroactive molecule-producing probiotics as therapeutic agents for the treatment of

  20. Agricultural by-products with bioactive effects: A multivariate approach to evaluate microbial and physicochemical changes in a fresh pork sausage enriched with phenolic compounds from olive vegetation water.

    PubMed

    Fasolato, Luca; Carraro, Lisa; Facco, Pierantonio; Cardazzo, Barbara; Balzan, Stefania; Taticchi, Agnese; Andreani, Nadia Andrea; Montemurro, Filomena; Martino, Maria Elena; Di Lecce, Giuseppe; Toschi, Tullia Gallina; Novelli, Enrico

    2016-07-02

    The use of phenolic compounds derived from agricultural by-products could be considered as an eco-friendly strategy for food preservation. In this study a purified phenol extract from olive vegetation water (PEOVW) was explored as a potential bioactive ingredient for meat products using Italian fresh sausage as food model. The research was developed in two steps: first, an in vitro delineation of the extract antimicrobial activities was performed, then, the PEOVW was tested in the food model to investigate the possible application in food manufacturing. The in vitro tests showed that PEOVW clearly inhibits the growth of food-borne pathogens such as Listeria monocytogenes and Staphylococcus aureus. The major part of Gram-positive strains was inhibited at the low concentrations (0.375-3mg/mL). In the production of raw sausages, two concentrates of PEOVW (L1: 0.075% and L2: 0.15%) were used taking into account both organoleptic traits and the bactericidal effects. A multivariate statistical approach allowed the definition of the microbial and physicochemical changes of sausages during the shelf life (14days). In general, the inclusion of the L2 concentration reduced the growth of several microbial targets, especially Staphylococcus spp. and LABs (2log10CFU/g reduction), while the increasing the growth of yeasts was observed. The reduction of microbial growth could be involved in the reduced lipolysis of raw sausages supplemented with PEOVW as highlighted by the lower amount of diacylglycerols. Moisture and aw had a significant effect on the variability of microbiological features, while food matrix (the sausages' environment) can mask the effects of PEOVW on other targets (e.g. Pseudomonas). Moreover, the molecular identification of the main representative taxa collected during the experimentation allowed the evaluation of the effects of phenols on the selection of bacteria. Genetic data suggested a possible strain selection based on storage time and the addition of

  1. [Influence of coordination compounds of germanium (IV) and stannum (IV) on activity of some microbial enzymes with glycolytic and proteolytic action].

    PubMed

    Varbanets', L D; Matseliukh, O V; Nidialkova, N A; Hudzenko, O V; Avdiiuk, K V; Shmatkova, N V; Seĭfullina, I Ĭ

    2014-01-01

    Influence of coordinative compounds of germanium (IV) and stanum (IV) (complexes of germanium (IV) with nicotinamide (Nad) [GeCl2(Nad)4]Cl2 (1) and complexes of stanum (IV) with 2-hydroxybenzoilhydrazone 4-dimetylaminobenzaldehide (2-OH-HBdb) [SnCl4(2-OH-Bdb-H)] (2), 3-hydroxy-2-naphtoilhydrazone 2-hydroxynaphtaldehide (3-OH-H2Lnf) [SnCl3(3-OH-HLnf)] (3) and izonicotinoilhydrazone 2-hydroxyibenzaldehide [SnCl3 (Is·H)] (4) on activity of peptidases 1 and 2 Bacillus thuringiensis, α-L-rhamnosidase Cryptococcus albidus, Eupenicillium erubescens and α-amylase Aspergillus flavus var. oryzae. Results testify that all studied compounds differ on their influence on activity of the enzymes tested: significantly don't change elastolytic activity of peptidases 1 and 2 B. thuringiensis, completely inhibit A. flavus var. oryzae amylase, activate or oppress of α-L-rhamnosidase C. albidus and E. erubescens. Considerable differences in compounds (3, 4) on activity observed in case of the last. It's possible that peculiarity of influence (1) in compare with (2-4) is connected with existence of different central atoms of complexants: germanium (IV) (1) and stanum (IV) (2-4). A certain analogy in oppression of C. albidus α-L-rhamnosidase by compounds (1) and (4) can explain with presence of a pyridinic ring at molecules of their ligands. The less activsty displayed compound (2) with coordinative knot {SnCl4ON}. Nature of compounds (3, 4) activity was absolutely different: essential increase of activity of C. albidus α-L-rhamnosidase and full oppression of E. erubescens α-L-rhamnosidase by compound (3), while the action of compound (4) was feed back. Taking into account identical coordination knot {SnCl3O2N} the major role in this case play change of a hydrazide fragment in molecules of their ligands.

  2. Neuroprotective Effects of Selected Microbial-Derived Phenolic Metabolites and Aroma Compounds from Wine in Human SH-SY5Y Neuroblastoma Cells and Their Putative Mechanisms of Action

    PubMed Central

    Esteban-Fernández, A.; Rendeiro, C.; Spencer, J. P. E.; del Coso, D. Gigorro; de Llano, M. D. González; Bartolomé, B.; Moreno-Arribas, M. V.

    2017-01-01

    Moderate wine consumption has shown the potential to delay the onset of neurodegenerative diseases. This study investigates the molecular mechanisms underlying the protective effects of wine-derived phenolic and aroma compounds in a neuroinflammation model based on SIN-1 stress-induced injury in SH-SY5Y neuroblastoma cells. Cell pretreatment with microbial metabolites found in blood after wine consumption, 3,4-dihydroxyphenylacetic (3,4-DHPA), 3-hydroxyphenylacetic acids and salicylic β-d-O-glucuronide, at physiologically concentrations (0.1–10 μM) resulted in increased cell viability versus SIN-1 control group (p < 0.05). Results also showed significant decreases in mitogen-activated protein kinase (MAPK) p38 and ERK1/2 activation as well as in downstream pro-apoptotic caspase-3 activity by some of the studied compounds. Moreover, pretreatment with p38, MEK, and ERK1/2-specific inhibitors, which have a phenolic-like structure, also resulted in an increase on cell survival and a reduction on caspase-3 activity levels. Overall, these results contribute with new evidences related to the neuroprotective actions of wine, pointing out that wine-derived human metabolites and aroma compounds may be effective at protecting neuroblastoma cells from nitrosative stress injury by inhibiting neuronal MAPK p38 and ERK1/2, as well as downstream caspase 3 activity. PMID:28352628

  3. Neuroprotective Effects of Selected Microbial-Derived Phenolic Metabolites and Aroma Compounds from Wine in Human SH-SY5Y Neuroblastoma Cells and Their Putative Mechanisms of Action.

    PubMed

    Esteban-Fernández, A; Rendeiro, C; Spencer, J P E; Del Coso, D Gigorro; de Llano, M D González; Bartolomé, B; Moreno-Arribas, M V

    2017-01-01

    Moderate wine consumption has shown the potential to delay the onset of neurodegenerative diseases. This study investigates the molecular mechanisms underlying the protective effects of wine-derived phenolic and aroma compounds in a neuroinflammation model based on SIN-1 stress-induced injury in SH-SY5Y neuroblastoma cells. Cell pretreatment with microbial metabolites found in blood after wine consumption, 3,4-dihydroxyphenylacetic (3,4-DHPA), 3-hydroxyphenylacetic acids and salicylic β-d-O-glucuronide, at physiologically concentrations (0.1-10 μM) resulted in increased cell viability versus SIN-1 control group (p < 0.05). Results also showed significant decreases in mitogen-activated protein kinase (MAPK) p38 and ERK1/2 activation as well as in downstream pro-apoptotic caspase-3 activity by some of the studied compounds. Moreover, pretreatment with p38, MEK, and ERK1/2-specific inhibitors, which have a phenolic-like structure, also resulted in an increase on cell survival and a reduction on caspase-3 activity levels. Overall, these results contribute with new evidences related to the neuroprotective actions of wine, pointing out that wine-derived human metabolites and aroma compounds may be effective at protecting neuroblastoma cells from nitrosative stress injury by inhibiting neuronal MAPK p38 and ERK1/2, as well as downstream caspase 3 activity.

  4. Microbial reduction of uranium

    USGS Publications Warehouse

    Lovley, D.R.; Phillips, E.J.P.; Gorby, Y.A.; Landa, E.R.

    1991-01-01

    REDUCTION of the soluble, oxidized form of uranium, U(VI), to insoluble U(IV) is an important mechanism for the immobilization of uranium in aquatic sediments and for the formation of some uranium ores1-10. U(VI) reduction has generally been regarded as an abiological reaction in which sulphide, molecular hydrogen or organic compounds function as the reductant1,2,5,11. Microbial involvement in U(VI) reduction has been considered to be limited to indirect effects, such as microbial metabolism providing the reduced compounds for abiological U(VI) reduction and microbial cell walls providing a surface to stimulate abiological U(VI) reduction1,12,13. We report here, however, that dissimilatory Fe(III)-reducing microorganisms can obtain energy for growth by electron transport to U(VI). This novel form of microbial metabolism can be much faster than commonly cited abiological mechanisms for U(VI) reduction. Not only do these findings expand the known potential terminal electron acceptors for microbial energy transduction, they offer a likely explanation for the deposition of uranium in aquatic sediments and aquifers, and suggest a method for biological remediation of environments contaminated with uranium.

  5. Biotechnological Aspects of Microbial Extracellular Electron Transfer

    PubMed Central

    Kato, Souichiro

    2015-01-01

    Extracellular electron transfer (EET) is a type of microbial respiration that enables electron transfer between microbial cells and extracellular solid materials, including naturally-occurring metal compounds and artificial electrodes. Microorganisms harboring EET abilities have received considerable attention for their various biotechnological applications, in addition to their contribution to global energy and material cycles. In this review, current knowledge on microbial EET and its application to diverse biotechnologies, including the bioremediation of toxic metals, recovery of useful metals, biocorrosion, and microbial electrochemical systems (microbial fuel cells and microbial electrosynthesis), were introduced. Two potential biotechnologies based on microbial EET, namely the electrochemical control of microbial metabolism and electrochemical stimulation of microbial symbiotic reactions (electric syntrophy), were also discussed. PMID:26004795

  6. Real-time detection of common microbial volatile organic compounds from medically important fungi by Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS).

    PubMed

    Scotter, Jennifer M; Langford, Vaughan S; Wilson, Paul F; McEwan, Murray J; Chambers, Stephen T

    2005-11-01

    We describe a new method, Selected Ion Flow Tube-Mass Spectrometry (SIFT-MS) for the rapid and sensitive real-time detection and quantification of volatile organic compounds from medically important fungi, grown on a range of laboratory media. SIFT-MS utilises the chemical ionisation reactions of mass-selected ions to characterise volatile organic compounds (VOCs) that are produced as metabolites from fungi. This technique has the distinct advantage over others in that it readily detects low molecular weight, reactive volatiles, and allows for real-time, quantitative monitoring. The fungi examined in this study were Aspergillus flavus, Aspergillus fumigatus, Candida albicans, Mucor racemosus, Fusarium solani, and Cryptococcus neoformans grown on or in malt extract agar, Columbia agar, Sabouraud's dextrose agar, blood agar, and brain-heart infusion broth. Common metabolites (ethanol, methanol, acetone, acetaldehyde, methanethiol, and crotonaldehyde) were detected and quantified. We found the fingerprint of volatiles, in terms of presence and quantity of volatiles to be strongly dependent on the culture medium, both in terms of variety and quantity of volatiles produced, but may form the basis for species specific identification of medically important fungi.

  7. Microbial Consortia Development and Microcosm and Column Experiments for Enhanced Bioremediation of Chlorinated Volatile Organic Compounds, West Branch Canal Creek Wetland Area, Aberdeen Proving Ground, Maryland

    USGS Publications Warehouse

    Lorah, Michelle M.; Majcher, Emily H.; Jones, Elizabeth J.; Voytek, Mary A.

    2008-01-01

    Chlorinated solvents, including 1,1,2,2-tetrachloroethane, tetrachloroethene, trichloroethene, carbon tetrachloride, and chloroform, are reaching land surface in localized areas of focused ground-water discharge (seeps) in a wetland and tidal creek in the West Branch Canal Creek area, Aberdeen Proving Ground, Maryland. In cooperation with the U.S. Army Garrison, Aberdeen Proving Ground, Maryland, the U.S. Geological Survey is developing enhanced bioremediation methods that simulate the natural anaerobic degradation that occurs without intervention in non-seep areas of the wetland. A combination of natural attenuation and enhanced bioremediation could provide a remedy for the discharging ground-water plumes that would minimize disturbance to the sensitive wetland ecosystem. Biostimulation (addition of organic substrate or nutrients) and bioaugmentation (addition of microbial consortium), applied either by direct injection at depth in the wetland sediments or by construction of a permeable reactive mat at the seep surface, were tested as possible methods to enhance anaerobic degradation in the seep areas. For the first phase of developing enhanced bioremediation methods for the contaminant mixtures in the seeps, laboratory studies were conducted to develop a microbial consortium to degrade 1,1,2,2-tetrachloroethane and its chlorinated daughter products under anaerobic conditions, and to test biostimulation and bioaugmentation of wetland sediment and reactive mat matrices in microcosms. The individual components required for the direct injection and reactive mat methods were then combined in column experiments to test them under groundwater- flow rates and contaminant concentrations observed in the field. Results showed that both direct injection and the reactive mat are promising remediation methods, although the success of direct injection likely would depend on adequately distributing and maintaining organic substrate throughout the wetland sediment in the seep

  8. Volatile Organic Compound emissions from soil: using Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry (PTR-TOF-MS) for the real time observation of microbial processes

    NASA Astrophysics Data System (ADS)

    Veres, P. R.; Behrendt, T.; Klapthor, A.; Meixner, F. X.; Williams, J.

    2014-08-01

    In this study we report on the emissions of volatile organic compounds (VOC) and nitric oxide (NO) from two contrasting soils (equatorial rainforest and arid cotton field) analyzed in a laboratory based dynamic chamber system. The effect of soil moisture and soil temperature on VOC and NO emission was examined in laboratory incubation experiments by measuring as a pre-saturated soil dried out. Our results suggest that real time monitoring of VOC emissions from soil using a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) instrument can be used to improve our understanding of the release mechanisms of trace gases (e.g. NO, N2O) that are involved in the nitrogen cycle. Moreover, we report on the release rate of various VOC species, many of which exhibit a temperature dependent response indicative of biological production, namely a temperature amplification factor (Q10) ∼ 2-3. Contrary to the conventional modeling of NO emissions from soils, that the release of NO from the overall community across the range of soil water content can be modeled as an optimum function, we suggest that VOC measurements indicate there exist multiple distinct contributing microbial guilds releasing NO. These microbial guilds could likely be individually identified with the observed VOC profiles. Using a cotton field soil sample from a Sache oasis (Taklimakan desert, Xinijang, P. R. China), we identify five VOC emission groups with varying degrees of NO co-emission. An equatorial rainforest soil (Suriname) was shown to emit a variety of VOC including acetaldehyde, acetone, DMS, formaldehyde, and isoprene that vary strongly and individually as a function of temperature and soil moisture content. PTR-TOF-MS with high time resolution, sensitivity, and molecular specificity is an ideal tool for the real time analysis of VOC and NO emitting processes in soil systems. These experiments can be used as a template for future experiments to more completely and specifically

  9. Microbial synthesis of Pd/Fe3O4, Au/Fe3O4 and PdAu/Fe3O4 nanocomposites for catalytic reduction of nitroaromatic compounds

    PubMed Central

    Tuo, Ya; Liu, Guangfei; Dong, Bin; Zhou, Jiti; Wang, Aijie; Wang, Jing; Jin, Ruofei; Lv, Hong; Dou, Zeou; Huang, Wenyu

    2015-01-01

    Magnetically recoverable noble metal nanoparticles are promising catalysts for chemical reactions. However, the chemical synthesis of these nanocatalysts generally causes environmental concern due to usage of toxic chemicals under extreme conditions. Here, Pd/Fe3O4, Au/Fe3O4 and PdAu/Fe3O4 nanocomposites are biosynthesized under ambient and physiological conditions by Shewanella oneidensis MR-1. Microbial cells firstly transform akaganeite into magnetite, which then serves as support for the further synthesis of Pd, Au and PdAu nanoparticles from respective precursor salts. Surface-bound cellular components and exopolysaccharides not only function as shape-directing agent to convert some Fe3O4 nanoparticles to nanorods, but also participate in the formation of PdAu alloy nanoparticles on magnetite. All these three kinds of magnetic nanocomposites can catalyze the reduction of 4-nitrophenol and some other nitroaromatic compounds by NaBH4. PdAu/Fe3O4 demonstrates higher catalytic activity than Pd/Fe3O4 and Au/Fe3O4. Moreover, the magnetic nanocomposites can be easily recovered through magnetic decantation after catalysis reaction. PdAu/Fe3O4 can be reused in at least eight successive cycles of 4-nitrophenol reduction. The biosynthesis approach presented here does not require harmful agents or rigorous conditions and thus provides facile and environmentally benign choice for the preparation of magnetic noble metal nanocatalysts. PMID:26310728

  10. Microbial volatile emissions as insect semiochemicals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We provide a synthesis of the literature describing biochemical interactions between microorganisms and arthropods by way of microbial volatile organic compound (MVOC) production. We explored important metabolic pathways involved in MVOC production and evaluated the functionality, generality, and e...

  11. Microbial naphthenic Acid degradation.

    PubMed

    Whitby, Corinne

    2010-01-01

    Naphthenic acids (NAs) are an important group of trace organic pollutants predominantly comprising saturated aliphatic and alicyclic carboxylic acids. NAs are ubiquitous; occurring naturally in hydrocarbon deposits (petroleum, oil sands, bitumen, and crude oils) and also have widespread industrial uses. Consequently, NAs can enter the environment from both natural and anthropogenic processes. NAs are highly toxic, recalcitrant compounds that persist in the environment for many years, and it is important to develop efficient bioremediation strategies to decrease both their abundance and toxicity in the environment. However, the diversity of microbial communities involved in NA-degradation, and the mechanisms by which NAs are biodegraded, are poorly understood. This lack of knowledge is mainly due to the difficulties in identifying and purifying individual carboxylic acid compounds from complex NA mixtures found in the environment, for microbial biodegradation studies. This paper will present an overview of NAs, their origin and fate in the environment, and their toxicity to the biota. The review describes the microbial degradation of both naturally occurring and chemically synthesized NAs. Proposed pathways for aerobic NA biodegradation, factors affecting NA biodegradation rates, and possible bioremediation strategies are also discussed.

  12. Transcriptional profiling of Gram-positive Arthrobacter in the phyllosphere: induction of pollutant degradation genes by natural plant phenolic compounds.

    PubMed

    Scheublin, Tanja R; Deusch, Simon; Moreno-Forero, Silvia K; Müller, Jochen A; van der Meer, Jan Roelof; Leveau, Johan H J

    2014-07-01

    Arthrobacter chlorophenolicus A6 is a Gram-positive, 4-chlorophenol-degrading soil bacterium that was recently shown to be an effective colonizer of plant leaf surfaces. The genetic basis for this phyllosphere competency is unknown. In this paper, we describe the genome-wide expression profile of A.chlorophenolicus on leaves of common bean (Phaseolus vulgaris) compared with growth on agar surfaces. In phyllosphere-grown cells, we found elevated expression of several genes known to contribute to epiphytic fitness, for example those involved in nutrient acquisition, attachment, stress response and horizontal gene transfer. A surprising result was the leaf-induced expression of a subset of the so-called cph genes for the degradation of 4-chlorophenol. This subset encodes the conversion of the phenolic compound hydroquinone to 3-oxoadipate, and was shown to be induced not only by 4-chlorophenol but also hydroquinone, its glycosylated derivative arbutin, and phenol. Small amounts of hydroquinone, but not arbutin or phenol, were detected in leaf surface washes of P.vulgaris by gas chromatography-mass spectrometry. Our findings illustrate the utility of genomics approaches for exploration and improved understanding of a microbial habitat. Also, they highlight the potential for phyllosphere-based priming of bacteria to stimulate pollutant degradation, which holds promise for the application of phylloremediation.

  13. Microbial methanogenesis in subsurface oil and coal.

    PubMed

    Meslé, Margaux; Dromart, Gilles; Oger, Philippe

    2013-11-01

    It is now clear that active methanogens are present in the deep-subsurface. This paper reviews microbial population structures and the biodegradation of organic compounds to methane in situ within oil reservoirs and coal deposits. It summarizes our current knowledge of methanogenes and methanogenesis, fermenters, synthrophs and microbial metabolism of complex organic compounds in these two widely occurring organic-rich subsurface environments. This review is not intended to be an exhaustive report of microbial diversity. Rather, it illustrates the similarities and differences between the two environments with specific examples, from the nature of the organic molecules to the methanogenic metabolic pathways and the structure of the microbial populations to demonstrate that widely diverging microbial populations show surprisingly similar metabolic capabilities.

  14. [Microbial degraders of some organochlorine compounds].

    PubMed

    Mitsevich, E V; Mitsevich, I P; Perelygin, V V

    2000-01-01

    A possibility of isolation of microorganisms, potential destructors of chlorinated organics from aged Vietnamese soils polluted with dioxine-containing defoliants was demonstrated. As an example, the ability of one isolated strain to metabolize pentachlorophenol and 2,4-dichlorophenoxyacetic acid was shown under laboratory conditions. An attempt was made to identify intermediates of pentachlorophenol metabolism using HPLC.

  15. Novel antimicrobial compounds from microbial sources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of antibiotics for agricultural and industrial applications is a controversial practice. In food animal production, antibiotics are widely administered through medicated feed to treat subclinical infections, as well as to prevent the spread of disease throughout the herd or flock. Antibiotic...

  16. 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.

  17. 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.

  18. Design of chemical space networks incorporating compound distance relationships

    PubMed Central

    de la Vega de León, Antonio; Bajorath, Jürgen

    2016-01-01

    Networks, in which nodes represent compounds and edges pairwise similarity relationships, are used as coordinate-free representations of chemical space. So-called chemical space networks (CSNs) provide intuitive access to structural relationships within compound data sets and can be annotated with activity information. However, in such similarity-based networks, distances between compounds are typically determined for layout purposes and clarity and have no chemical meaning. By contrast, inter-compound distances as a measure of dissimilarity can be directly obtained from coordinate-based representations of chemical space. Herein, we introduce a CSN variant that incorporates compound distance relationships and thus further increases the information content of compound networks. The design was facilitated by adapting the Kamada-Kawai algorithm. Kamada-Kawai networks are the first CSNs that are based on numerical similarity measures, but do not depend on chosen similarity threshold values. PMID:28184279

  19. Design of chemical space networks incorporating compound distance relationships.

    PubMed

    de la Vega de León, Antonio; Bajorath, Jürgen

    2016-01-01

    Networks, in which nodes represent compounds and edges pairwise similarity relationships, are used as coordinate-free representations of chemical space. So-called chemical space networks (CSNs) provide intuitive access to structural relationships within compound data sets and can be annotated with activity information. However, in such similarity-based networks, distances between compounds are typically determined for layout purposes and clarity and have no chemical meaning. By contrast, inter-compound distances as a measure of dissimilarity can be directly obtained from coordinate-based representations of chemical space. Herein, we introduce a CSN variant that incorporates compound distance relationships and thus further increases the information content of compound networks. The design was facilitated by adapting the Kamada-Kawai algorithm. Kamada-Kawai networks are the first CSNs that are based on numerical similarity measures, but do not depend on chosen similarity threshold values.

  20. Microbial methods of reducing technetium

    DOEpatents

    Wildung, Raymond E [Richland, WA; Garland, Thomas R [Greybull, WY; Gorby, Yuri A [Richland, WA; Hess, Nancy J [Benton City, WA; Li, Shu-Mei W [Richland, WA; Plymale, Andrew E [Richland, WA

    2001-01-01

    The present invention is directed toward a method for microbial reduction of a technetium compound to form other compounds of value in medical imaging. The technetium compound is combined in a mixture with non-growing microbial cells which contain a technetium-reducing enzyme system, a stabilizing agent and an electron donor in a saline solution under anaerobic conditions. The mixture is substantially free of an inorganic technetium reducing agent and its reduction products. The resulting product is Tc of lower oxidation states, the form of which can be partially controlled by the stabilizing agent. It has been discovered that the microorganisms Shewanella alga, strain Bry and Shewanelia putrifacians, strain CN-32 contain the necessary enzyme systems for technetium reduction and can form both mono nuclear and polynuclear reduced Tc species depending on the stabilizing agent.

  1. Psychogenic non-epileptic seizures: so-called psychiatric comorbidity and underlying defense mechanisms

    PubMed Central

    Beghi, Massimiliano; Negrini, Paola Beffa; Perin, Cecilia; Peroni, Federica; Magaudda, Adriana; Cerri, Cesare; Cornaggia, Cesare Maria

    2015-01-01

    In Diagnostic and Statistical Manual of Mental Disorders, fifth edition, psychogenic non-epileptic seizures (PNES) do not have a unique classification as they can be found within different categories: conversion, dissociative, and somatization disorders. The ICD-10, instead, considers PNES within dissociative disorders, merging the dissociative disorders and conversion disorders, although the underlying defense mechanisms are different. The literature data show that PNES are associated with cluster B (mainly borderline) personality disorders and/or to people with depressive or anxiety disorders. Defense mechanisms in patients with PNES with a prevalence of anxious/depressive symptoms are of “neurotic” type; their goal is to lead to a “split”, either vertical (dissociation) or horizontal (repression). The majority of patients with this type of PNES have alexithymia traits, meaning that they had difficulties in feeling or perceiving emotions. In subjects where PNES are associated with a borderline personality, in which the symbolic function is lost, the defense mechanisms are of a more archaic nature (denial). PNES with different underlying defense mechanisms have different prognoses (despite similar severity of PNES) and need usually a different treatment (pharmacological or psychological). Thus, it appears superfluous to talk about psychiatric comorbidity, since PNES are a different symptomatic expression of specific psychiatric disorders. PMID:26491330

  2. ACTIVE IMMUNITY PRODUCED BY SO CALLED BALANCED OR NEUTRAL MIXTURES OF DIPHTHERIA TOXIN AND ANTITOXIN.

    PubMed

    Smith, T

    1909-03-01

    The foregoing and earlier data taken together demonstrate that an active immunity lasting several years can be produced in guinea-pigs, by the injection of toxin-antitoxin mixtures which have no recognizable harmful effect either immediate or remote. They also show, what might have been anticipated, that under the same conditions mixtures which produce local lesions and which, therefore, contain an excess of toxin produce a much higher degree of immunity than the neutral mixtures, and that an excess of antitoxin reduces the possibility of producing an active immunity, and may extinguish it altogether. There is, therefore, a certain definite relation between the components of the mixture and the degree of immunity producible. Furthermore, toxin-antitoxin mixtures do not change materially within five days at room temperature. They are apparently more efficacious at the end of forty-eight hours than immediately after preparation. The experiments finally prove that a relatively high degree of active immunity can be induced by a harmless procedure, whereas the use of toxin alone leading to very severe local lesions is incapable of producing more than an insignificant protection. The method, therefore, invites further tests in regard to its ultimate applicability to the human being. Unless the subcutis of the guinea-pig reacts to toxin-antitoxin mixtures in a manner peculiar to itself, a practical, easily controlled method for active immunization can be worked out which should afford a larger protection than the serum alone and avoid the complications associated with horse serum. That proportion of toxin and antitoxin which would produce the highest desirable immunity consistent with the least discomfort would have to be carefully worked out for the human subject. From the nature of the immunity induced it is obvious, however, that such a method of immunization cannot take the place of a large dose of antitoxin in exposed individuals who must be protected at once. It would be applicable only as a general protective measure without reference to any immediate danger, since it would take several weeks, perhaps longer, to perfect the attainable immunity. Passing to the theoretical aspects of the facts observed, we find no publications bearing directly upon the subject before us. Madsen has, however, approached it very closely in his experiments on the immunization of animals with mixtures not fully balanced, or, in other words, in which the "toxones" were still free. He found that the injection of such mixtures in rabbits, goats and horses produces an active immunity. He makes the significant remark that perhaps in the immunizing capacity we may possess the keenest reagent for a poison which is not able to exert any toxic action in the body. This is fully borne out by the experiments described, for in these we pass beyond the visible spectrum, so to speak, of the toxin-antitoxin effects, and we are able to recognize toxic action only by the lasting immunizing effects. Another publication which touches upon some phases of the same problem is that of Morgenroth on the union between toxin and antitoxin. Morgenroth brought out the fact that a given toxin-antitoxin mixture is more toxic when injected directly into the circulation than when injected under the skin. Thus, an L(+) dose of 0.78 c.c. toxin + one unit antitoxin applied subcutaneously was of the same toxicity as 0.68 c.c. toxin + one unit antitoxin injected into the circulation. When the mixture had stood twenty-four hours this (L(+)) dose was still 0.78 c.c. subcutaneously, but it had risen to 0.74 c.c. when introduced by the intracardiac route. The author makes two deductions from these results. He assumes that the velocity of reaction between toxin and antitoxin is slow, and that the union is not completed until the mixture has stood twenty-four hours. Hence, the L(+) dose of toxin injected into the blood is higher after twenty-four hours than immediately after mixing the toxin and antitoxin. He furthermore explains the fact that the subcutaneous L(+) dose remains the same whether the mixture is injected at once or after twenty-four hours, by assuming that in the subcutis of the guinea-pig there is a catalytic acceleration of the union of toxin and antitoxin. In view of the writer's results it seems that not only immediately, but four to five days after the preparation of the mixture of toxin and antitoxin, there are still toxic substances available for the production of immunity in the body of the guinea-pig, when the dose of toxin in the mixture is far below the L(0) or neutral level. These toxins may be free, either because uncombined in vitro, or else because the mixture is partially dissociated in vivo, or there may be a third possibility. It is obvious that Morgenroth's investigations, however extensive and thorough, have not exhausted the subject, for both these inferences are incompatible with his. Perhaps his recent important studies on the recovery of toxin from its combination with antitoxin with weak acids may throw more light on this subject. The only conclusion which we may safely draw at this time is that the toxin-antitoxin mixture produces two sets of effects, essentially identical, however. One is visible, as injury (oedema, loss of hair, superficial and deep necrosis of skin, paralysis and death), and corresponds to the toxin spectrum of Ehrlich. The other is invisible and manifests itself only in degrees of active immunity. At what ratio of toxin to antitoxin in the mixture active immunity is no longer produced will vary somewhat with the guinea-pig used, but it is evident that traces of immunity are still transmitted to the young when the amount of toxin approaches half the L(0) dose.

  3. MALARIAL PIGMENT (SO-CALLED MELANIN): ITS NATURE AND MODE OF PRODUCTION.

    PubMed

    Brown, W H

    1911-02-01

    1. Two important methods for the study of malarial pigment are described. (a) A method for obtaining a solution of malarial pigment from fixed tissues without the removal of a trace of hemoglobin from the red blood corpuscles. (b) A method for obtaining an iron reaction in malarial pigment. 2. By comparing the bleach reactions and solubility of melanins and malarial pigment, the dissimilarity of the two classes of pigments has been demonstrated. 3. The spectroscopic examination of a solution of malarial pigment proves conclusively that the pigment is hematin. 4. It is suggested that the action of a proteolytic enzyme of the malarial parasite upon the hemoglobin of the red blood corpuscle is the most probable mode of elaboration of malarial pigment. 5. The difficulty with which the human organism disposes of malarial pigment indicates that the production of hematin cannot be considered as a normal intermediate process in the formation of bile pigments from hemoglobin.

  4. [The so-called "chocolate cyst"--frequently misinterpreted as ovarian endometriosis?].

    PubMed

    Christensen, B; Schindler, A E

    1996-09-01

    Limitation of morphological diagnostic and possible misinterpretations are shown in a patient with anamnestic ovarian endometriosis. In cases of "chocolate cysts" it is necessary to differentiate between ovarian endometriosis and functional cysts. Hints for the existence of a functional cyst are an atypical past history or perioperative findings. Biochemical analysis of the cyst fluid may lead to a correct diagnosis.

  5. [Literature of so-called "clinical research": structure and trends, 1991-2010].

    PubMed

    Schubert, András; Somogyi, Anikó

    2014-11-30

    The authors studied trends and patterns in the literature of research labeled as clinical (i.e., having the word "clinical" in their title) in the period between 1991 and 2010. The main findings are: 1. The growth of the literature under study was somewhat stronger than that of the overall medical literature. 2. The dominance of the USA is strong but is challenged by some of the most rapidly developing countries (particularly in the Far-East region: China, Korea) in total production, and by the developed European countries in highly cited publications. The eminence of Italy is remarkable. 3. In comparing the medical fields, the most striking tendencies are the increase of oncology and the attenuation of internal medicine. Surgery is steadily growing in size but decreasing in its citation influence. 4. Word frequency studies support the ever growing weight of oncology and also of genetics. 5. Beyond the thematic changes, word frequency studies also reveal a substantial change in attitude: in the period under study more and more effort was made on emphasizing the usefulness, efficiency and risks of the results in contrast with the more descriptive, investigative approach of the past. The role of therapy is growing, the role of diagnostics is decreasing. The knowledge of these trends and patterns may orient health and science policy makers to cope appropriately with the ever changing world of clinical research.

  6. Theory and experiment in so-called pulse-interval pitch.

    PubMed

    Whitfield, I C

    1981-01-01

    Moore [1980] has criticised the conclusions of Whitfield [1979] who used an alternating pulsatile stimulus [Seebeck, 1843], and found that the predominating interpulse intervals produced in a single auditory nerve fibre did not correspond to the perceived pitch. Moore's criticism depends on an assumption he makes that is not in fact borne out by the experiments.

  7. Composition and properties of the so-called 'diamond-like' amorphous carbon films

    NASA Technical Reports Server (NTRS)

    Angus, J. C.; Stultz, J. E.; Shiller, P. J.; Macdonald, J. R.; Mirtich, M. J.

    1984-01-01

    The composition of amorphous 'diamond-like' films made by direct low energy ion beam deposition, R.F. discharge and sputtering was determined by nuclear reaction analysis, IR spectroscopy and microcombustion chemical analysis. The nuclear reaction analysis showed very similar hydrogen depth profiles for all three types of samples. The atomic ratio of hydrogen to carbon was approximately 0.2 at the film surface and rose to approximately 1.0 at a depth of 500 A. The integrated intensity of the C-H stretching band at about 2900 per cm indicates that the amount of chemically bonded hydrogen is less than the total hydrogen content. Combustion analysis confirmed the overall atomic ratio of hydrogen to carbon determined by nuclear reaction analysis. The chemical state of the non-bonded hydrogen was not determined; however, the effective diffusion coefficient computed from the hydrogen depth profile was extremely low. This indicates either that the films are exceedingly impermeable or that the non-bonded hydrogen requires an additional activated step to leave the films, e.g., desorption or chemical reaction.

  8. The Pfannenstiel or so called "bikini cut": still effective more than 100 years after first description.

    PubMed

    Kisielinski, K; Conze, J; Murken, A H; Lenzen, N N; Klinge, U; Schumpelick, V

    2004-08-01

    The original Pfannenstiel incision is discussed including the technique, history, current indications, advantages, and disadvantages. Excellent cosmetic results, principles of less traumatic surgery, and a rare incisional hernia complication rate of about 0-2%, as well as long-time use characterise this access path to the pelvic organs first described by the German gynaecologist in 1900. Complications of nerve damage, however, should be recognised, especially when extending the incision too far laterally.

  9. So-called "central retinal vein occlusion". II. Venous stasis retinopathy.

    PubMed

    Hayreh, S S

    1976-01-01

    28 patients (29 eyes) with venous stasis retinopathy (VSR) were studied. This study indicates that VSR is a self-limited, chronic and comparatively benign condition as compared to hemorrhagic retinopathy. No patient with VSR progressed to hemorrhagic retinopathy. The main complication which required management in VSR was the deterioration of central visual acuity (VA) due to development of macular edema which, if untreated, ended in cystoid macular degeneration and permanent central scotoma. Thus the indication for treatment in these cases was the fall of central VA. Ten eyes showed no deterioration of vision throughout follow-up (group I) and hence required no treatment. The remaining 19 eyes developed deterioration of vision: 5 eyes (4 patients) amongst these were not treated (group II) while the other 14 eyes (group III) were treated by systemic corticosteroids, to control the macula edema starting with a dose of 40-60 mg of oral prednisolone daily and gradually tapering to a maintenance dose. The results of group III cases strongly suggested that adequate doses of systemic steroids have a distinct beneficial effect on the VA -they help to prevent deterioration of vision and in the recovery of deteriorated vision. However, these patients require therapy for months or even longer during the course of VSR; on stopping the therapy, poor VA recurred in ten of these eyes. This factor may limit the usefulness of this therapy, if contraindications to such prolonged steriod therapy or serious side-effects of steroid therapy exist in a patient. In such cases one may be confronted with the dilemma of either not treating them and running a fairly high risk of permanent loss of central vision, or treating them with adequate doses of systemic steriods, retaining good VA but running the risk of side effects. While evaluating the effectiveness of steroid therapy, the improvement in VA should be the primary criterion because the fundus appearances almost always show no significant improvement for weeks although the VA rapidly returns to a normal level.

  10. SO-CALLED BIOLOGICAL TESTS FOR ADRENALIN IN BLOOD, WITH SOME OBSERVATIONS ON ARTERIAL HYPERTONUS

    PubMed Central

    Stewart, G. N.

    1911-01-01

    1. The combination of a biological test object on which adrenalin causes contraction of smooth muscle (perfused blood-vessels or the uterus in certain conditions) with a biological test object on which it produces inhibition of contraction of smooth muscle (intestine) greatly diminishes the chance of error in testing blood (or other body liquids) for adrenalin. A control experiment with adrenalin solutions should, in general, accompany each observation on the blood. 2. When properly chosen biological tests are employed, no evidence is obtained of the presence of adrenalin in detectable amount in normal blood taken from the general circulation. 3. In a case of nephritis with albuminuria and persistently high arterial pressure, the pressure was diminished by forced breathing. The washing out of carbon dioxide seemed to be a factor in this diminution as well as the mechanical interference with the circulation. In this case, the administration of large doses of sodium bicarbonate was associated with a marked diminution in the blood pressure. 4. In another case with persistently high blood pressure, the drawing off of cerebrospinal fluid caused a distinct diminution in the arterial pressure, presumably by lowering the intracranial pressure. No pressor substance was detected in the cerebrospinal fluid. PMID:19867483

  11. Importance of the so-called 'other' sexually-transmitted diseases.

    PubMed

    Willcox, R R

    1975-08-01

    (1) Some data are presented concerning the frequency and potential morbidity of sexually-transmitted organisms other than T. pallidum or N. gonorrhoeae. (2) Most of the diseases with which these organisms are associated are more prevalent than syphilis and some, at least in one sex, are as common as gonorrhoea. A number appear to carry considerable morbidity, which in the case of Type II herpes virus--if it is responsible for cervical cancer--may ultimately cause more fatalities than syphilis. (3) It is concluded: (a) that, if syphilis and gonorrhoea were reduced to the point of representing no public health concern, many other sexually-transmitted conditions would still remain to pose significant problems: and (b) that health education and other methods of prevention should, where possible, be designed to take into consideration the epidemiological implications of the other organisms listed.

  12. [Assessment of the coronary circulation regulation by means of the so-called isometric contraction index].

    PubMed

    Urbaszek, W; Löwe, H R; Rentsch, W; Pankau, H; Günther, K

    1976-08-01

    The index of isometric contraction formed from the quotient period of isometric contraction in the erect position by period of isometric contraction in lying position gives the possibility to separate between cardially sufficient and cardially insufficient patients with adequately disturbed regulation of the cardiac circulation. The recognition of early stages of the disturbed left-ventricular function is possible. The use of an adequate exact technique in gaining the primary data is to be presumed. Corrections of the frequency of the index of isometric contraction do not improve the evidence. In the borderline region of the index of isometric contraction with values between 1.03 and 1.1 in questionable cases a further differentiation into still normal or already latent insufficient will do by the analysis of the trend of the index of isometric contraction after the application of medicaments. The determination of the change of the direction of the index of isometric contraction after peroral application of nitroglycerin would be justifiable in routine work after the recognition of the initiaction increases in patients with latent heart insufficiency, in patients with a healthy heart it decreases. The clinical value of the index of isometric contraction as a simple test of the circulatory function is highly to be estimated.

  13. [Regarding respiration and the so-called "animal heat." An historical sketch].

    PubMed

    de Micheli, A

    2001-01-01

    According to Aristotle and Galen, the essential function of the respiration phenomenon was to cool the blood. Towards the middle of the XVI Century, Miguel Servet suggested, in his treatise Christianismi restitutio..., that the inspired air could have other functions besides cooling the blood. Later, Joseph Black thought that respiration was a combustion. In the light of the advances in chemistry achieved in the XVII Century, the English scientist Adair Crawford and the French chemist Antoine-Laurent Lavoisier conceived, in the second half of that century, the first general and quantitative theories on the origin of animal heat. Both these authors had the conviction that the "inflammable element", which will be called oxygen, was not formed in the pulmonary territory, but could be absorbed by the blood. Oxygen, foreseen by Mayow at the end of XVII Century, was discovered by Joseph Priestley in 1774. Lavoisier gave the name of oxygen to this gas and firmly established that the respiration phenomenon consists essentially in a process of combustion. The mathematician Joseph-Louis Lagrange, native of Turin, suggested that animal heat originates in all breathing tissues. This phenomenon was verified and described in detail by the biologist Lazzaro Spallanzani, professor at the University of Pavia. Dissemination, in the scientific world, of the new chemical nomenclature and of the respiratory theory, closely related to it, was based fundamentally on the works "Méthode de nomenclature chimique..." (1787) and "Traité élémentaire de chimie..." (1789). During the XIX Century, studies on the phenomenon of animal respiration continued and fundamental discoveries in this subject were attained, such as conversion of hemoglobin to oxyhemoglobin once oxygen had been fixed. Now it is possible to study the regulating mechanisms of the energetic metabolism of the myocardium in vivo, which allows decisive interventions in certain cardiopathies, such as in acute ischemic cardiopathy.

  14. The revival of a so-called rotten fish: the ontogeny of the Devonian acanthodian Triazeugacanthus

    PubMed Central

    Chevrinais, Marion; Cloutier, Richard; Sire, Jean-Yves

    2015-01-01

    Since its original description as a chordate, the Late Devonian Scaumenella mesacanthi has been interpreted alternately as a prochordate, a larval ostracoderm and an immature acanthodian. For the past 30 years, these minute specimens were generally considered as decayed acanthodians, most of them belonging to Triazeugacanthus affinis. Among the abundant material of ‘Scaumenella’, we identified a size series of 188 specimens of Triazeugacanthus based on otolith characteristics. Despite taphonomic alteration, we describe proportional growth and progressive appearance of skeletal elements through size increase. Three ontogenetic stages are identified based on squamation extent, ossification completion and allometric growth. We demonstrate that what has been interpreted previously as various degrees of decomposition corresponds to ontogenetic changes. PMID:25694507

  15. How far do patients with sensory ataxia benefit from so-called "proprioceptive rehabilitation"?

    PubMed

    Missaoui, B; Thoumie, P

    2009-01-01

    A rehabilitation program including foot sensory stimulation, balance and gait training with limited vision was performed in 24 patients with clinically defined sensory ataxia. There were 15 patients with bilateral somatosensory loss related to chronic neuropathy and nine patients with unilateral loss-related to multiple sclerosis. After training, balance control assessed using the Berg Balance Test improved similarly in both groups, and Romberg's sign disappeared in some patients, suggesting an improvement in dynamic balance and in the proprioceptive contribution. Conversely, balance assessed on a static force platform remained similar in the open-eyes condition and improved in the closed-eyes condition only in patients with unilateral sensory loss. These results show that ataxic patients can improve their balance with better results in dynamic conditions and that the relative contribution of proprioceptive and visual inputs may depend on the extent of somatosensory loss.

  16. Mechanisms of the Nyos carbon dioxide disaster and of so-called phreatic steam eruptions

    NASA Astrophysics Data System (ADS)

    Tazieff, Haroun

    1989-11-01

    During the night of August 21, 1986, a huge volume of concentrated CO 2 was emitted by the crater (maar) of Nyos, Cameroon. It killed more than 1700 people and all animal life as far as 14 km away. Two hypotheses have been put forward to account for this disaster. The chronologically first one imputes it to have been a phreatic eruption, exceptionally CO 2-rich, as had been the case in February 1979 on the Diëng Plateau in Central Java, Indonesia, where the erupting crater was lake-less. The second one claims a limnic origin for the CO 2 release, through an overturn of the 220 m-deep Lake Nyos, the hypolimnium of which was supposed to be oversaturated by dissolved gas of volcanic origin. The present paper points to six observed facts for which the eruptive hypothesis easily accounts, and which the authors of the limnic one do ignore.

  17. The so-called death drive, an indispensable force for any subjective life.

    PubMed

    Penot, Bernard

    2017-04-01

    The psychoanalytic movement has difficulty in overcoming the malaise bequeathed by what Freud wanted to call the 'death drive'. This term remains doubly problematic: first because the indispensable antagonist of Eros-binding cannot be reduced to a particular drive; and secondly because this Anteros plays a vital role in subjectivization. The Freudian idea of the 'death drive' has in addition the drawback of confusing dissociative thrust (unbinding) with the aggressive component of libidinal cathexis. Now it is precisely the lack of articulation between them that leads to deconstructing it. For it is constantly observed that in the psychic register aggression is much more fixing than unbinding. The essential role of Anteros/unbinding in the process of subjectivization can be illustrated through several key operations in subjective development: sublimatory activity and its renunciation of pleasure-discharge, the work of mourning opposed to melancholic fixation, the intricating-unbinding parental function, and finally the psychoanalytic treatment and its work of analysis. This means we should cease to anathematize the dynamic component of unbinding as 'of death' and seek to explain the concept of subjectivization better.

  18. Intraneural pseudocyst (so-called ganglion) in an unusual retroperitoneal periadnexal location?

    PubMed Central

    2014-01-01

    A case of an unusual unilocular cystic lesion of diameter 7 cm located retroperitoneally in the pelvis in close connection to the right adnexa of a 61 year-old woman is presented. Macroscopically, the lesion had a smooth outer and inner surface and was filled with translucent fluid. Histological examination revealed a fibrous and hyalinized wall which lacked a specific lining. Numerous nerve bundles in the cyst wall constituted the most conspicuous element of its histology possibly with some contribution of perineurial and/or mesothelial components. The morphology and immunohistochemistry speak for an intraneural pseudocyst sometimes called intraneural ganglion cyst which is rare in this location. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1357862917132314 PMID:25044274

  19. FURTHER OBSERVATIONS AND EXPERIMENTS ON GOITRE (SO CALLED THYROID CARCINOMA) IN BROOK TROUT (SALVELINUS FONTINALIS)

    PubMed Central

    Marine, David

    1914-01-01

    1. Goitre in fish is a non-infectious, non-contagious, symptomatic manifestation of a fault of nutrition, the exact biochemical nature of which has not been determined. 2. Feeding the highly artificial and incomplete diet of liver is the major etiological factor in bringing about this fault of nutrition which is at once corrected by feeding whole sea fish. 3. Water plays no essential part in the etiology, transmission, or distribution of the disease in the fish of this hatchery. PMID:19867750

  20. An Exegetic Study of the So-Called Proposition of Confucian Aesthetics

    ERIC Educational Resources Information Center

    Wang, Yi; Fu, Xiaowei

    2008-01-01

    Since Wang Guowei and Cai Yuanpei introduced the concepts of aesthetics and aesthetic education, respectively, to China in the early twentieth century, there has been a strong tendency in many of the aesthetic discussions to examine ancient texts and materials using modern concepts of aesthetics. In particular, sentences with the character-word…

  1. Aggressive variants of follicular cell derived thyroid carcinoma; the so called 'real thyroid carcinomas'.

    PubMed

    Baloch, Zubair; LiVolsi, Virginia A; Tondon, Rashmi

    2013-09-01

    The pathological diagnoses and classification schemes for thyroid carcinoma have changed over the past 20 years and continue to do so. New entities have been described and molecular analyses have suggested better characterisation and grouping of certain tumours. Because some of the lesions have been named differently by different authors, clinicians and patients may be confused as to what a specific patient's lesion represents. In this review, we discuss the thyroid tumours of follicular origin which are clinically unusual but important to recognise as their behaviour may be aggressive, they may not respond to radioiodine treatment and they may cause significant mortality. This paper describes these important but rare lesions, their pathological features, important clinicopathological correlations, molecular correlates and prognostic implications.

  2. Modification of radiosensitivity by the so-called tissue recovery stimulator. I. Radiosensitizing effects of solcoseryl.

    PubMed

    Kumar, A; Kimura, H; Aoyama, T; Sugahara, T

    1992-12-01

    The effect of solcoseryl on the growth, radiosensitization and ability of V79 cells to recover from X-ray-induced damage has been observed. Solcoseryl at 0.8 mg/ml was the optimal concentration for the stimulation of cell growth. Increased sensitivity to X-irradiation was found in the shoulder region of V79 cells treated before and after irradiation with solcoseryl (0.8 mg/ml). The Dq and extrapolation number (n) decreased. Solcoseryl treatment apparently does not reduce split dose recovery or inhibit the repair of potentially lethal damage. Flow cytofluorometry studies of the cell cycle distribution and mitotic index show that solcoseryl inhibits the expression of radiation-induced cell arrest in the G2 phase of the cell cycle. Although this action increases radiation sensitization, additional mechanisms probably exist.

  3. Microbial Biotransformation to Obtain New Antifungals

    PubMed Central

    Bianchini, Luiz F.; Arruda, Maria F. C.; Vieira, Sergio R.; Campelo, Patrícia M. S.; Grégio, Ana M. T.; Rosa, Edvaldo A. R.

    2015-01-01

    Antifungal drugs belong to few chemical groups and such low diversity limits the therapeutic choices. The urgent need of innovative options has pushed researchers to search new bioactive molecules. Literature regarding the last 15 years reveals that different research groups have used different approaches to achieve such goal. However, the discovery of molecules with different mechanisms of action still demands considerable time and efforts. This review was conceived to present how Pharmaceutical Biotechnology might contribute to the discovery of molecules with antifungal properties by microbial biotransformation procedures. Authors present some aspects of (1) microbial biotransformation of herbal medicines and food; (2) possibility of major and minor molecular amendments in existing molecules by biocatalysis; (3) methodological improvements in processes involving whole cells and immobilized enzymes; (4) potential of endophytic fungi to produce antimicrobials by bioconversions; and (5) in silico research driving to the improvement of molecules. All these issues belong to a new conception of transformation procedures, so-called “green chemistry,” which aims the highest possible efficiency with reduced production of waste and the smallest environmental impact. PMID:26733974

  4. Microbial fuel cells: novel microbial physiologies and engineering approaches.

    PubMed

    Lovley, Derek R

    2006-06-01

    The possibility of generating electricity with microbial fuel cells has been recognized for some time, but practical applications have been slow to develop. The recent development of a microbial fuel cell that can harvest electricity from the organic matter stored in marine sediments has demonstrated the feasibility of producing useful amounts of electricity in remote environments. Further study of these systems has led to the discovery of microorganisms that conserve energy to support their growth by completely oxidizing organic compounds to carbon dioxide with direct electron transfer to electrodes. This suggests that self-sustaining microbial fuel cells that can effectively convert a diverse range of waste organic matter or renewable biomass to electricity are feasible. Significant progress has recently been made to increase the power output of systems designed to convert organic wastes to electricity, but substantial additional optimization will be required for large-scale electricity production.

  5. A new strategy of glucose supply in a microbial fermentation model

    NASA Astrophysics Data System (ADS)

    Kasbawati, Gunawan, A. Y.; Sidarto, K. A.; Hertadi, R.

    2015-09-01

    Strategy of glucose supply to achieve an optimal productivity of ethanol production of a yeast cell is one of the main features in a microbial fermentation process. Beside a known continuous glucose supply, in this study we consider a new supply strategy so called the on-off supply. An optimal control theory is applied to the fermentation system to find the optimal rate of glucose supply and time of supply. The optimization problem is solved numerically using Differential Evolutionary algorithm. We find two alternative solutions that we can choose to get the similar result: either long period process with low supply or short period process with high glucose supply.

  6. 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

  7. 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

  8. Microbial synthesis of poly(beta-hydroxyalkanoates) bearing phenyl groups from pseudomonas putida: chemical structure and characterization.

    PubMed

    Abraham, G A; Gallardo, A; San Roman, J; Olivera, E R; Jodra, R; García, B; Miñambres, B; García, J L; Luengo, J M

    2001-01-01

    New poly(beta-hydroxyalkanoates) having aromatics groups (so-called PHPhAs) from a microbial origin have been characterized. These polymers were produced and accumulated as reserve materials when a beta-oxidation mutant of Pseudomonas putida U, disrupted in the gene that encodes the 3-ketoacyl-CoA thiolase (fadA), was cultured in a chemically defined medium containing different aromatic fatty acids (6-phenylhexanoic acid, 7-phenylheptanoic acid, a mixture of them, or 8-phenyloctanoic acid) as carbon sources. The polymers were extracted from the bacteria, purified and characterized by using (13)C nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). Structural studies revealed that when 6-phenylhexanoic acid was added to the cultures, an homopolymer (poly-3-hydroxy-6-phenylhexanoate) was accumulated. The feeding with 8-phenyloctanoic acid and 7-phenylheptanoic acid leads to the formation of copolymers of the corresponding units with the n - 2 carbons formed after deacetylation, copoly(3-hydroxy-8-phenyloctanoate-3-hydroxy-6-phenylhexanoate) and copoly(3-hydroxy-7-phenylheptanoate-3-hydroxy-5-phenylvalerate), respectively. The mixture of 6-phenylhexanoic acid and 7-phenylheptanoic acid gave rise to the corresponding terpolymer, copoly(3-hydroxy-7-phenylheptanoate-3-hydroxy-6-phenylhexanoate-3-hydroxy-5-phenylvalerate). Studies on the chemical structure of these three polyesters revealed that they were true copolymers but not a mixture of homopolymers and that the different monomeric units were randomly incorporated in the macromolecular chains. Thermal behavior and molecular weight distribution were also discussed. These compounds had a dual attractive interest in function of (i) their broad use as biodegradable polymers and (ii) their possible biomedical applications.

  9. Microbial response to triepthylphosphate

    SciTech Connect

    Hazen, T.C.; Santo Domingo, J.W.; Berry, C.J.

    1997-05-01

    The effect of triethylphosphate (TEP) on the activity of a landfill aquifer microbial community was evaluated using standard techniques and in situ hybridizations with phylogenetic probes. Benzene was used as an external carbon source to monitor degradation of an aromatic compound in TEP amended microcosms. Microscopical and viable counts were higher in TEP containing microcosms when compared to unamended controls. A significant increase in metabolic activity was also observed for TEP amended samples as determined by the number of cells hybridizing to an eubacterial probe. In addition, the number of beta and gamma Proteobacteria increased from undetectable levels prior to the study to 15-29% of the total bacteria in microcosms containing TEP and benzene. In these microcosms, nearly 40% of the benzene was degraded during the incubation period compared to less than 5% in unamended microcosms. While TEP has previously been used as an alternate phosphate source in the bioremediation of chlorinated aliphatics, this study shows that it can also stimulate the microbial degradation of aromatics in phosphate limited aquifers.

  10. The microbial nitrogen cycle.

    PubMed

    Jetten, Mike S M

    2008-11-01

    This special issue highlights several recent discoveries in the microbial nitrogen cycle including the diversity of nitrogen-fixing bacteria in special habitats, distribution and contribution of aerobic ammonium oxidation by bacteria and crenarchaea in various aquatic and terrestrial ecosystems, regulation of metabolism in nitrifying bacteria, the molecular diversity of denitrifying microorganisms and their enzymes, the functional diversity of freshwater and marine anammox bacteria, the physiology of nitrite-dependent anaerobic methane oxidation and the degradation of recalcitrant organic nitrogen compounds. Simultaneously the articles in this issue show that many questions still need to be addressed, and that the microbes involved in catalyzing the nitrogen conversions still harbour many secrets that need to be disclosed to fully understand the biogeochemical nitrogen cycle, and make future predictions and global modelling possible.

  11. Recent advances in amino acid production by microbial cells.

    PubMed

    Hirasawa, Takashi; Shimizu, Hiroshi

    2016-12-01

    Amino acids have been utilized for the production of foods, animal feeds and pharmaceuticals. After the discovery of the glutamic acid-producing bacterium Corynebacterium glutamicum by Japanese researchers, the production of amino acids, which are primary metabolites, has been achieved using various microbial cells as hosts. Recently, metabolic engineering studies on the rational design of amino acid-producing microbial cells have been successfully conducted. Moreover, the technology of systems biology has been applied to metabolic engineering for the creation of amino acid-producing microbial cells. Currently, new technologies including synthetic biology, single-cell analysis, and evolutionary engineering have been utilized to create amino acid-producing microbial cells. In addition, useful compounds from amino acids have been produced by microbial cells. Here, current researches into the metabolic engineering of microbial cells toward production of amino acids and amino acid-related compounds are reviewed.

  12. Microbial synthetic biology for human therapeutics.

    PubMed

    Jain, Aastha; Bhatia, Pooja; Chugh, Archana

    2012-06-01

    The emerging field of synthetic biology holds tremendous potential for developing novel drugs to treat various human conditions. The current study discusses the scope of synthetic biology for human therapeutics via microbial approach. In this context, synthetic biology aims at designing, engineering and building new microbial synthetic cells that do not pre-exist in nature as well as re-engineer existing microbes for synthesis of therapeutic products. It is expected that the construction of novel microbial genetic circuitry for human therapeutics will greatly benefit from the data generated by 'omics' approaches and multidisciplinary nature of synthetic biology. Development of novel antimicrobial drugs and vaccines by engineering microbial systems are a promising area of research in the field of synthetic biology for human theragnostics. Expression of plant based medicinal compounds in the microbial system using synthetic biology tools is another avenue dealt in the present study. Additionally, the study suggest that the traditional medicinal knowledge can do value addition for developing novel drugs in the microbial systems using synthetic biology tools. The presented work envisions the success of synthetic biology for human therapeutics via microbial approach in a holistic manner. Keeping this in view, various legal and socio-ethical concerns emerging from the use of synthetic biology via microbial approach such as patenting, biosafety and biosecurity issues have been touched upon in the later sections.

  13. Beyond the genome: community-level analysis of the microbial world.

    PubMed

    Zarraonaindia, Iratxe; Smith, Daniel P; Gilbert, Jack A

    2013-03-01

    The development of culture-independent strategies to study microbial diversity and function has led to a revolution in microbial ecology, enabling us to address fundamental questions about the distribution of microbes and their influence on Earth's biogeochemical cycles. This article discusses some of the progress that scientists have made with the use of so-called "omic" techniques (metagenomics, metatranscriptomics, and metaproteomics) and the limitations and major challenges these approaches are currently facing. These 'omic methods have been used to describe the taxonomic structure of microbial communities in different environments and to discover new genes and enzymes of industrial and medical interest. However, microbial community structure varies in different spatial and temporal scales and none of the 'omic techniques are individually able to elucidate the complex aspects of microbial communities and ecosystems. In this article we highlight the importance of a spatiotemporal sampling design, together with a multilevel 'omic approach and a community analysis strategy (association networks and modeling) to examine and predict interacting microbial communities and their impact on the environment.

  14. Soil microbial communities respond differently to three chemically defined polyphenols

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High molecular weight polyphenols (tannins) that leach into the soil may affect microbial populations, for example by serving as substrates for microbial respiration or by selecting for certain microbes . In this study we examined how three phenolic compounds that represent environmentally widespre...

  15. Analysis of phenolic compounds for poultry feeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phenolic compounds have generated significant interest recently as feed additives that can impart bioactive characteristics such as anti-oxidant, anti-microbial, and anti-fungal properties to a feed formulation [1-2]. Such natural compounds may offer some preventive benefit to the routine administra...

  16. Hypersaline Microbial Mat Lipid Biomarkers

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda L.; Embaye, Tsegereda; Turk, Kendra A.; Summons, Roger E.

    2002-01-01

    Lipid biomarkers and compound specific isotopic abundances are powerful tools for studies of contemporary microbial ecosystems. Knowledge of the relationship of biomarkers to microbial physiology and community structure creates important links for understanding the nature of early organisms and paleoenvironments. Our recent work has focused on the hypersaline microbial mats in evaporation ponds at Guerrero Negro, Baja California Sur, Mexico. Specific biomarkers for diatoms, cyanobacteria, archaea, green nonsulfur (GNS), sulfate reducing, sulfur oxidizing and methanotrophic bacteria have been identified. Analyses of the ester-bound fatty acids indicate a highly diverse microbial community, dominated by photosynthetic organisms at the surface. The delta C-13 of cyanobacterial biomarkers such as the monomethylalkanes and hopanoids are consistent with the delta C-13 measured for bulk mat (-10%o), while a GNS biomarker, wax esters (WXE), suggests a more depleted delta C-13 for GNS biomass (-16%o). This isotopic relationship is different than that observed in mats at Octopus Spring, Yellowstone National Park (YSNP) where GNS appear to grow photoheterotrophic ally. WXE abundance, while relatively low, is most pronounced in an anaerobic zone just below the cyanobacterial layer. The WXE isotope composition at GN suggests that these bacteria utilize photoautotrophy incorporating dissolved inorganic carbon (DIC) via the 3-hydroxypropionate pathway using H2S or H2.

  17. Microbial Regulation in Gorgonian Corals

    PubMed Central

    Hunt, Laura R.; Smith, Stephanie M.; Downum, Kelsey R.; Mydlarz, Laura D.

    2012-01-01

    Gorgonian corals possess many novel natural products that could potentially mediate coral-bacterial interactions. Since many bacteria use quorum sensing (QS) signals to facilitate colonization of host organisms, regulation of prokaryotic cell-to-cell communication may represent an important bacterial control mechanism. In the present study, we examined extracts of twelve species of Caribbean gorgonian corals, for mechanisms that regulate microbial colonization, such as antibacterial activity and QS regulatory activity. Ethanol extracts of gorgonians collected from Puerto Rico and the Florida Keys showed a range of both antibacterial and QS activities using a specific Pseudomonas aeruginosa QS reporter, sensitive to long chain AHLs and a short chain N-acylhomoserine lactones (AHL) biosensor, Chromobacterium violaceium. Overall, the gorgonian corals had higher antimicrobial activity against non-marine strains when compared to marine strains. Pseudopterogorgia americana, Pseusopterogorgia acerosa, and Pseudoplexuara flexuosa had the highest QS inhibitory effect. Interestingly, Pseudoplexuara porosa extracts stimulated QS activity with a striking 17-fold increase in signal. The stimulation of QS by P. porosa or other elements of the holobiont may encourage colonization or recruitment of specific microbial species. Overall, these results suggest the presence of novel stimulatory QS, inhibitory QS and bactericidal compounds in gorgonian corals. A better understanding of these compounds may reveal insight into coral-microbial ecology and whether a therapeutic potential exists. PMID:22822369

  18. Microbial syntrophy: interaction for the common good.

    PubMed

    Morris, Brandon E L; Henneberger, Ruth; Huber, Harald; Moissl-Eichinger, Christine

    2013-05-01

    Classical definitions of syntrophy focus on a process, performed through metabolic interaction between dependent microbial partners, such as the degradation of complex organic compounds under anoxic conditions. However, examples from past and current scientific discoveries suggest that a new, simple but wider definition is necessary to cover all aspects of microbial syntrophy. We suggest the term 'obligately mutualistic metabolism', which still focuses on microbial metabolic cooperation but also includes an ecological aspect: the benefit for both partners. By the combined metabolic activity of microorganisms, endergonic reactions can become exergonic through the efficient removal of products and therefore enable a microbial community to survive with minimal energy resources. Here, we explain the principles of classical and non-classical syntrophy and illustrate the concepts with various examples. We present biochemical fundamentals that allow microorganism to survive under a range of environmental conditions and to drive important biogeochemical processes. Novel technologies have contributed to the understanding of syntrophic relationships in cultured and uncultured systems. Recent research highlights that obligately mutualistic metabolism is not limited to certain metabolic pathways nor to certain environments or microorganisms. This beneficial microbial interaction is not restricted to the transfer of reducing agents such as hydrogen or formate, but can also involve the exchange of organic, sulfurous- and nitrogenous compounds or the removal of toxic compounds.

  19. 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.

  20. EFFECT OF TEMPERATURE ON THE C ISOTOPIC VALUE OF MICROBIAL LIPIDS APPLIED TO DETERMINE C USAGE IN MICROBIAL COMMUNITIES

    EPA Science Inventory

    The combination of compound specific stable isotopic analysis with phospholipid fatty acid (PLFAS) analysis is useful in determining the source of organic carbon used by groups of a microbial community. Determination of the effect of certain environmental parameters is important ...

  1. Soil microbial community of abandoned sand fields.

    PubMed

    Elhottová, D; Szili-Kovács, T; Tríska, J

    2002-01-01

    Microbiological evaluation of sandy grassland soils from two different stages of secondary succession on abandoned fields (4 and 8 years old fallow) was carried out as a part of research focused on restoration of semi-natural vegetation communities in Kiskunság National Park in Hungary. There was an apparent total N and organic C enrichment, stimulation of microbial growth and microbial community structure change on fields abandoned by agricultural practice (small family farm) in comparison with native undisturbed grassland. A successional trend of the microbial community was found after 4 and 8 years of fallow-lying soil. It consisted in a shift of r-survival strategy to more efficient C economy, in a decrease of specific respiration and metabolic activity, forced accumulation of storage bacterial compounds and increased fungal distribution. The composition of microbial phospholipid fatty acids mixture of soils abandoned at various times was significantly different.

  2. Microbial degradation of petroleum hydrocarbons.

    PubMed

    Varjani, Sunita J

    2017-01-01

    Petroleum hydrocarbon pollutants are recalcitrant compounds and are classified as priority pollutants. Cleaning up of these pollutants from environment is a real world problem. Bioremediation has become a major method employed in restoration of petroleum hydrocarbon polluted environments that makes use of natural microbial biodegradation activity. Petroleum hydrocarbons utilizing microorganisms are ubiquitously distributed in environment. They naturally biodegrade pollutants and thereby remove them from the environment. Removal of petroleum hydrocarbon pollutants from environment by applying oleophilic microorganisms (individual isolate/consortium of microorganisms) is ecofriendly and economic. Microbial biodegradation of petroleum hydrocarbon pollutants employs the enzyme catalytic activities of microorganisms to enhance the rate of pollutants degradation. This article provides an overview about bioremediation for petroleum hydrocarbon pollutants. It also includes explanation about hydrocarbon metabolism in microorganisms with a special focus on new insights obtained during past couple of years.

  3. TRIFLUOROMETHYL COMPOUNDS OF GERMANIUM

    DTIC Science & Technology

    FLUORIDES, *GERMANIUM COMPOUNDS, *HALIDES, *ORGANOMETALLIC COMPOUNDS, ALKYL RADICALS, ARSENIC COMPOUNDS, CHEMICAL BONDS, CHEMICAL REACTIONS ...CHLORIDES, CHLORINE COMPOUNDS, HYDROLYSIS, IODIDES, METHYL RADICALS, POTASSIUM COMPOUNDS, PYROLYSIS, STABILITY, SYNTHESIS, TIN COMPOUNDS.

  4. 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.

  5. Raman Spectroscopy of Microbial Pigments

    PubMed Central

    Edwards, Howell G. M.; Oren, Aharon

    2014-01-01

    Raman spectroscopy is a rapid nondestructive technique providing spectroscopic and structural information on both organic and inorganic molecular compounds. Extensive applications for the method in the characterization of pigments have been found. Due to the high sensitivity of Raman spectroscopy for the detection of chlorophylls, carotenoids, scytonemin, and a range of other pigments found in the microbial world, it is an excellent technique to monitor the presence of such pigments, both in pure cultures and in environmental samples. Miniaturized portable handheld instruments are available; these instruments can be used to detect pigments in microbiological samples of different types and origins under field conditions. PMID:24682303

  6. The microbial fate of carbon in high-latitude seas: Impact of the microbial loop on oceanic uptake of CO{sub 2}

    SciTech Connect

    Yager, P.L.

    1996-12-31

    This dissertation examines pelagic microbial processes in high-latitude seas, how they affect regional and global carbon cycling, and how they might respond to hypothesized changes in climate. Critical to these interests is the effect of cold temperature on bacterial activity. Also important is the extent to which marine biological processes in general impact the inorganic carbon cycle. The study area is the Northeast Water (NEW) Polynya, a seasonally-recurrent opening in the permanent ice situated over the northeastern Greenland continental shelf. This work was part of an international, multi-disciplinary research project studying carbon cycling in the coastal Arctic. The first chapter describes a simple model which links a complex marine food web to a simplified ocean and atmosphere. The second chapter investigates the inorganic carbon inventory of the summertime NEW Polynya surface waters to establish the effect of biological processes on the air-sea pCO{sub 2} gradient. The third and fourth chapters use a kinetic approach to examine microbial activities in the NEW Polynya as a function of temperature and dissolved organic substrate concentration, testing the so-called Pomeroy hypothesis that microbial activity is disproportionately reduced at low environmental temperatures owing to increased organic substrate requirements. Together, the suite of data collected on microbial activities, cell size, and grazing pressure suggest how unique survival strategies adopted by an active population of high-latitude bacteria may contribute to, rather than detract from, an efficient biological carbon pump.

  7. Newest developments in compounding of wooden fibre composites WFC

    NASA Astrophysics Data System (ADS)

    Brunkau, M.

    2014-05-01

    Compounding trials in 2010 at HENSCHEL Compounding Technology Centre showed significant improvements of mechanical properties by using a co-rotating twin screw extruder combined with a newly developed machine the so-called AGGLOMAT. Together with TechWood International, UK a common patent was applied by the end of 2010 under DE 10 2010 060 911.0. Hereby the extruder stands for compounding and drying in a single process. The polymers are mixed and homogenized with the natural fibers in a continuous process. All materials are dosed via loss-in-weight feeders in a gravimetric mode. To suck out the moisture of up to 10% from the natural fibers so-called degassing side feeders are used. These side feeders are fitted out with counter-rotating twin screws which move into the process unit to avoid material deposits. The bigger volume creates an effective drying with moisture content below 0.5%. The homogenous compound will be discharged almost without pressure into an AGGLOMAT which purpose is to cool down the melt and transform it into agglomerates. The particle size of 1 to 10 mm is determined by choppers controlled by a frequency drive. This bears the advantage that the length of fibers is not shorten to much and increase mechanical properties of compound. In a further step the agglomerates are fed into a counter rotating twin screw extruder for production of WFC-profiles. Compared to previous systems the physical properties of profiles have been improved and allow new applications such as the construction of simply housings. In addition to that the throughput could be increased by 30% which delivers higher economical performance and faster return of investment.

  8. Biodegradation of nitroaromatic compounds.

    PubMed

    Spain, J C

    1995-01-01

    Nitroaromatic compounds are released into the biosphere almost exclusively from anthropogenic sources. Some compounds are produced by incomplete combustion of fossil fuels; others are used as synthetic intermediates, dyes, pesticides, and explosives. Recent research revealed a number of microbial systems capable of transforming or biodegrading nitroaromatic compounds. Anaerobic bacteria can reduce the nitro group via nitroso and hydroxylamino intermediates to the corresponding amines. Isolates of Desulfovibrio spp. can use nitroaromatic compounds as their source of nitrogen. They can also reduce 2,4,6-trinitrotoluene to 2,4,6-triaminotoluene. Several strains of Clostridium can catalyze a similar reduction and also seem to be able to degrade the molecule to small aliphatic acids. Anaerobic systems have been demonstrated to destroy munitions and pesticides in soil. Fungi can extensively degrade or mineralize a variety of nitroaromatic compounds. For example, Phanerochaete chrysosporium mineralizes 2,4-dinitrotoluene and 2,4,6-trinitrotoluene and shows promise as the basis for bioremediation strategies. The anaerobic bacteria and the fungi mentioned above mostly transform nitroaromatic compounds via fortuitous reactions. In contrast, a number of nitroaromatic compounds can serve as growth substrates for aerobic bacteria. Removal or productive metabolism of nitro groups can be accomplished by four different strategies. (a) Some bacteria can reduce the aromatic ring of dinitro and trinitro compounds by the addition of a hydride ion to form a hydride-Meisenheimer complex, which subsequently rearomatizes with the elimination of nitrite. (b) Monooxygenase enzymes can add a single oxygen atom and eliminate the nitro group from nitrophenols. (c) Dioxygenase enzymes can insert two hydroxyl groups into the aromatic ring and precipitate the spontaneous elimination of the nitro group from a variety of nitroaromatic compounds. (d) Reduction of the nitro group to the corresponding

  9. Use of antimicrobial peptides against microbial biofilms: advantages and limits.

    PubMed

    Batoni, Giovanna; Maisetta, Giuseppantonio; Brancatisano, Franca Lisa; Esin, Semih; Campa, Mario

    2011-01-01

    The formation of surface-attached cellular agglomerates, the so-called biofilms, contributes significantly to bacterial resistance to antibiotics and innate host defenses. Bacterial biofilms are associated to various pathological conditions in humans such as cystic fibrosis, colonization of indwelling medical devices and dental plaque formation involved in caries and periodontitis. Over the last years, natural antimicrobial peptides (AMPs) have attracted considerable interest as a new class of antimicrobial drugs for a number of reasons. Among these, there are the broad activity spectrum, the relative selectivity towards their targets (microbial membranes), the rapid mechanism of action and, above all, the low frequency in selecting resistant strains. Since biofilm resistance to antibiotics is mainly due to the slow growth rate and low metabolic activity of bacteria in such community, the use of AMPs to inhibit biofilm formation could be potentially an attractive therapeutic approach. In fact, due to the prevalent mechanism of action of AMPs, which relies on their ability to permeabilize and/or to form pores within the cytoplasmic membranes, they have a high potential to act also on slow growing or even non-growing bacteria. This review will highlight the most important findings obtained testing AMPs in in vitro and in vivo models of bacterial biofilms, pointing out the possible advantages and limits of their use against microbial biofilm-related infections.

  10. A Chemical Perspective on Microalgal-Microbial Interactions.

    PubMed

    Hom, Erik F Y; Aiyar, Prasad; Schaeme, Daniel; Mittag, Maria; Sasso, Severin

    2015-11-01

    The exchange of chemical compounds is central to the interactions of microalgae with other microorganisms. Although foundational for many food webs, these interactions have been poorly studied compared with higher plant-microbe interactions. Emerging insights have begun to reveal how these interactions and the participating chemical compounds shape microbial communities and broadly impact biogeochemical processes.

  11. 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.

  12. Contribution of microbial carbon to soil fractions: significance of diverse microbial group biochemistry

    NASA Astrophysics Data System (ADS)

    Throckmorton, H.; Bird, J. A.; Dane, L.; Firestone, M. K.; Horwath, W. R.

    2011-12-01

    The importance of diverse microbial groups to soil C maintenance is still a matter of debate. This study follows the turnover of 13C labeled nonliving residues from diverse microbial groups into soil physical fractions in situ in a temperate forest in California (CA) and a tropical forest in Puerto Rico (PR), during 5 sampling points per site- over a 3 and 2 year period, respectively. Microbial groups include fungi, actinomycetes, Gm(+) bacteria, and Gm(-) bacteria, isolated from CA and PR soils to obtain temperate and tropical isolates composited of 3-4 species per group. The selected density fractionation approach isolated: a "light fraction" (LF), non-mineral aggregate "occluded fraction" (OF), and a "mineral bound fraction" (MF). Pyrolysis gas chromatography mass spectrometry (Py-GC-MS) was employed to characterize microbial group isolates, whole soils, and fractions. Microbial isolates contained unique biochemical fingerprints: temperate and tropical fungi and tropical Gm(-) were characterized by a low abundance of phenol, benzene, and N-compounds compared with other microbial group isolates. Py-GC-MS revealed compositional differences among soil fractions at both sites, likely attributed to differences in the decomposition stage and C source material (ie. plant vs. microbial). For both sites, benzene and N-compounds were greatest in the MF; lignin and phenol compounds were greatest in the LF; and lipids were greatest in the OF. The trend for polysaccharides differed between sites, with the greatest concentration in the CA OF; and for PR with the lowest concentration in the OF, and similar concentrations in the LF and MF. SOM chemistry was most similar between sites in the LF, compared with the OF and MF, suggesting that differences in SOM chemistry between sites may be more attributed to differential decomposition processes than unique litter quality inputs. A substantial portion of microbial C moved from the LF into the OF, and the MF by the first sampling

  13. Anodic and cathodic microbial communities in single chamber microbial fuel cells.

    PubMed

    Daghio, Matteo; Gandolfi, Isabella; Bestetti, Giuseppina; Franzetti, Andrea; Guerrini, Edoardo; Cristiani, Pierangela

    2015-01-25

    Microbial fuel cells (MFCs) are a rapidly growing technology for energy production from wastewater and biomasses. In a MFC, a microbial biofilm oxidizes organic matter and transfers electrons from reduced compounds to an anode as the electron acceptor by extracellular electron transfer (EET). The aim of this work was to characterize the microbial communities operating in a Single Chamber Microbial Fuel Cell (SCMFC) fed with acetate and inoculated with a biogas digestate in order to gain more insight into anodic and cathodic EET. Taxonomic characterization of the communities was carried out by Illumina sequencing of a fragment of the 16S rRNA gene. Microorganisms belonging to Geovibrio genus and purple non-sulfur (PNS) bacteria were found to be dominant in the anodic biofilm. The alkaliphilic genus Nitrincola and anaerobic microorganisms belonging to Porphyromonadaceae family were the most abundant bacteria in the cathodic biofilm.

  14. Microbial Metabolism in Serpentinite Fluids

    NASA Astrophysics Data System (ADS)

    Crespo-Medina, M.; Brazelton, W. J.; Twing, K. I.; Kubo, M.; Hoehler, T. M.; Schrenk, M. O.

    2013-12-01

    Serpentinization is the process in which ultramafic rocks, characteristic of the upper mantle, react with water liberating mantle carbon and reducing power to potenially support chemosynthetic microbial communities. These communities may be important mediators of carbon and energy exchange between the deep Earth and the surface biosphere. Our work focuses on the Coast Range Ophiolite Microbial Observatory (CROMO) in Northern California where subsurface fluids are accessible through a series of wells. Preliminary analyses indicate that the highly basic fluids (pH 9-12) have low microbial diversity, but there is limited knowledge about the metabolic capabilities of these communties. Metagenomic data from similar serpentine environments [1] have identified Betaproteobacteria belonging to the order Burkholderiales and Gram-positive bacteria from the order Clostridiales as key components of the serpentine microbiome. In an effort to better characterize the microbial community, metabolism, and geochemistry at CROMO, fluids from two representative wells (N08B and CSWold) were sampled during recent field campaigns. Geochemical characterization of the fluids includes measurements of dissolved gases (H2, CO, CH4), dissolved inorganic and organic carbon, volatile fatty acids, and nutrients. The wells selected can be differentiated in that N08B had higher pH (10-11), lower dissolved oxygen, and cell counts ranging from 105-106 cells mL-1 of fluid, with an abundance of the betaproteobacterium Hydrogenophaga. In contrast, fluids from CSWold have slightly lower pH (9-9.5), DO, and conductivity, as well as higher TDN and TDP. CSWold fluid is also characterized for having lower cell counts (~103 cells mL-1) and an abundance of Dethiobacter, a taxon within the phylum Clostridiales. Microcosm experiments were conducted with the purpose of monitoring carbon fixation, methanotrophy and metabolism of small organic compounds, such as acetate and formate, while tracing changes in fluid

  15. Microbial Production of Isoprenoids Enabled by Synthetic Biology

    PubMed Central

    Immethun, Cheryl M.; Hoynes-O’Connor, Allison G.; Balassy, Andrea; Moon, Tae Seok

    2013-01-01

    Microorganisms transform inexpensive carbon sources into highly functionalized compounds without toxic by-product generation or significant energy consumption. By redesigning the natural biosynthetic pathways in an industrially suited host, microbial cell factories can produce complex compounds for a variety of industries. Isoprenoids include many medically important compounds such as antioxidants and anticancer and antimalarial drugs, all of which have been produced microbially. While a biosynthetic pathway could be simply transferred to the production host, the titers would become economically feasible when it is rationally designed, built, and optimized through synthetic biology tools. These tools have been implemented by a number of research groups, with new tools pledging further improvements in yields and expansion to new medically relevant compounds. This review focuses on the microbial production of isoprenoids for the health industry and the advancements though synthetic biology. PMID:23577007

  16. High Temperature Superconducting Compounds.

    DTIC Science & Technology

    1999-04-02

    addition to superconducting films, non-superconducting mixed-valence manganite perovskites, which exhibit so-called colossal magnetoresistance were grown...The manganites are unique in that their charge carriers are believed to be almost 100% spin polarized. These materials were combined with the...brought about by the injection of spin polarized carriers from the manganite into the curate. This work may make possible new classes of devices based on

  17. Microbial hydrogen production

    SciTech Connect

    Weaver, P.F.; Maness, P.C.; Martin, S.

    1995-09-01

    Photosynthetic bacteria inhabit an anaerobic or microaerophilic world where H{sub 2} is produced and consumed as a shared intermediary metabolite. Within a given bacterial isolate there are as many as 4 to 6 distinct enzymes that function to evolve or consume H{sub 2}. Three of the H{sub 2}-evolving physiologies involving three different enzymes from photosynthetic bacteria have been examined in detail for commercial viability. Nitrogenase-mediated H{sub 2} production completely dissimilates many soluble organic compounds to H{sub 2} and CO{sub 2} at rates up to 131 {mu}mol H{sub 2}{sm_bullet}min{sup -1}{sm_bullet}g cdw{sup -1} and can remain active for up to 20 days. This metabolism is very energy intensive, however, which limits solar conversion efficiencies. Fermentative hydrogenase can produce H{sub 2} at rates of 440 {mu}mol{sm_bullet}min{sup -1}{sm_bullet}g cdw{sup -1} at low levels of irradiation over indefinite periods. The equilibrium for this activity is low (<0.15 atmospheres), thereby requiring gas sparging, vacuuming, or microbial scavenging to retain prolonged activity. Microbial H{sub 2} production from the CO component of synthesis or producer gases maximally reaches activities of 1.5 mmol{sm_bullet}min{sup -1}{sm_bullet}g cdw{sup -1}. Mass transport of gaseous CO into an aqueous bacterial suspension is the rate-limiting step. Increased gas pressure strongly accelerates these rates. Immobilized bacteria on solid supports at ambient pressures also show enhanced shift activity when the bulk water is drained away. Scaled-up bioreactors with 100-200 cc bed volume have been constructed and tested. The near-term goal of this portion of the project is to engineer and economically evaluate a prototype system for the biological production of H{sub 2} from biomass. The CO shift enables a positive selection technique for O{sub 2}-resistant, H{sub 2}-evolving bacterial enzymes from nature.

  18. 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...

  19. Polybenzimidazole compounds

    DOEpatents

    Klaehn, John R [Idaho Falls, ID; Peterson, Eric S [Idaho Falls, ID; Orme, Christopher J [Shelley, ID; Jones, Michael G [Chubbuck, ID; Wertsching, Alan K [Idaho Falls, ID; Luther, Thomas A [Idaho Falls, ID; Trowbridge, Tammy L [Idaho Falls, ID

    2011-11-22

    A PBI compound includes imidazole nitrogens at least a portion of which are substituted with a moiety containing a carbonyl group, the substituted imidazole nitrogens being bonded to carbon of the carbonyl group. At least 85% of the nitrogens may be substituted. The carbonyl-containing moiety may include RCO--, where R is alkoxy or haloalkyl. The PBI compound may exhibit a first temperature marking an onset of weight loss corresponding to reversion of the substituted PBI that is less than a second temperature marking an onset of decomposition of an otherwise identical PBI compound without the substituted moiety. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may use more than 5 equivalents in relation to the imidazole nitrogens to be substituted.

  20. Polybenzimidazole compounds

    DOEpatents

    Klaehn, John R.; Peterson, Eric S.; Wertsching, Alan K.; Orme, Christopher J.; Luther, Thomas A.; Jones, Michael G.

    2010-08-10

    A PBI compound that includes imidazole nitrogens, at least a portion of which are substituted with an organic-inorganic hybrid moiety. At least 85% of the imidazole nitrogens may be substituted. The organic-inorganic hybrid moiety may be an organosilane moiety, for example, (R)Me.sub.2SiCH.sub.2--, where R is selected from among methyl, phenyl, vinyl, and allyl. The PBI compound may exhibit similar thermal properties in comparison to the unsubstituted PBI. The PBI compound may exhibit a solubility in an organic solvent greater than the solubility of the unsubstituted PBI. The PBI compound may be included in separatory media. A substituted PBI synthesis method may include providing a parent PBI in a less than 5 wt % solvent solution. Substituting may occur at about room temperature and/or at about atmospheric pressure. Substituting may use at least five equivalents in relation to the imidazole nitrogens to be substituted or, preferably, about fifteen equivalents.

  1. 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.

  2. Research advances on microbial genetics in China in 2015.

    PubMed

    Jianping, Xie; Yubo, Han; Gang, Liu; Linquan, Bai

    2016-09-01

    In 2015, there are significant progresses in many aspects of the microbial genetics in China. To showcase the contribution of Chinese scientists in microbial genetics, this review surveys several notable progresses in microbial genetics made largely by Chinese scientists, and some key findings are highlighted. For the basic microbial genetics, the components, structures and functions of many macromolecule complexes involved in gene expression regulation have been elucidated. Moreover, the molecular basis underlying the recognition of foreign nucleic acids by microbial immune systems was unveiled. We also illustrated the biosynthetic pathways and regulators of multiple microbial compounds, novel enzyme reactions, and new mechanisms regulating microbial gene expression. And new findings were obtained in the microbial development, evolution and population genetics. For the industrial microbiology, more understanding on the molecular basis of the microbial factory has been gained. For the pathogenic microbiology, the genetic circuits of several pathogens were depicted, and significant progresses were achieved for understanding the pathogen-host interaction and revealing the genetic mechanisms underlying antimicrobial resistance, emerging pathogens and environmental microorganisms at the genomic level. In future, the genetic diversity of microbes can be used to obtain specific products, while gut microbiome is gathering momentum.

  3. Growth-altering microbial interactions are responsive to chemical context

    PubMed Central

    2017-01-01

    Microbial interactions are ubiquitous in nature, and are equally as relevant to human wellbeing as the identities of the interacting microbes. However, microbial interactions are difficult to measure and characterize. Furthermore, there is growing evidence that they are not fixed, but dependent on environmental context. We present a novel workflow for inferring microbial interactions that integrates semi-automated image analysis with a colony stamping mechanism, with the overall effect of improving throughput and reproducibility of colony interaction assays. We apply our approach to infer interactions among bacterial species associated with the normal lung microbiome, and how those interactions are altered by the presence of benzo[a]pyrene, a carcinogenic compound found in cigarettes. We found that the presence of this single compound changed the interaction network, demonstrating that microbial interactions are indeed dynamic and responsive to local chemical context. PMID:28319121

  4. Growth-altering microbial interactions are responsive to chemical context.

    PubMed

    Liu, Angela; Archer, Anne M; Biggs, Matthew B; Papin, Jason A

    2017-01-01

    Microbial interactions are ubiquitous in nature, and are equally as relevant to human wellbeing as the identities of the interacting microbes. However, microbial interactions are difficult to measure and characterize. Furthermore, there is growing evidence that they are not fixed, but dependent on environmental context. We present a novel workflow for inferring microbial interactions that integrates semi-automated image analysis with a colony stamping mechanism, with the overall effect of improving throughput and reproducibility of colony interaction assays. We apply our approach to infer interactions among bacterial species associated with the normal lung microbiome, and how those interactions are altered by the presence of benzo[a]pyrene, a carcinogenic compound found in cigarettes. We found that the presence of this single compound changed the interaction network, demonstrating that microbial interactions are indeed dynamic and responsive to local chemical context.

  5. 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.

  6. Characteristics of volatile organic compounds emission profiles from hot road bitumens.

    PubMed

    Boczkaj, Grzegorz; Przyjazny, Andrzej; Kamiński, Marian

    2014-07-01

    A procedure for the investigation and comparison of volatile organic compounds (VOCs) emission profiles to the atmosphere from road bitumens with various degrees of oxidation is proposed. The procedure makes use of headspace analysis and gas chromatography with universal as well as selective detection, including gas chromatography-mass spectrometry (GC-MS). The studies revealed that so-called vacuum residue, which is the main component of the charge, contains variable VOC concentrations, from trace to relatively high ones, depending on the extent of thermal cracking in the boiler of the vacuum distillation column. The VOC content in the oxidation product, so-called oxidized paving bitumen, is similarly varied. There are major differences in VOC emission profiles between vacuum residue and oxidized bitumens undergoing thermal cracking. The VOC content in oxidized bitumens, which did not undergo thermal cracking, increases with the degree of oxidation of bitumens. The studies revealed that the total VOC content increases from about 120 ppm for the raw vacuum residue to about 1900 ppm for so-called bitumen 35/50. The amount of volatile sulfur compounds (VSCs) in the volatile fraction of fumes of oxidized bitumens increases with the degree of oxidation of bitumen and constitutes from 0.34% to 3.66% (w/w). The contribution of volatile nitrogen compounds (VNCs) to total VOC content remains constant for the investigated types of bitumens (from 0.16 to 0.28% (w/w) of total VOCs). The results of these studies can also find use during the selection of appropriate bitumen additives to minimize their malodorousness. The obtained data append the existing knowledge on VOC emission from oxidized bitumens. They should be included in reports on the environmental impact of facilities in which hot bitumen binders are used.

  7. Microbial life in a liquid asphalt desert.

    PubMed

    Schulze-Makuch, Dirk; Haque, Shirin; de Sousa Antonio, Marina Resendes; Ali, Denzil; Hosein, Riad; Song, Young C; Yang, Jinshu; Zaikova, Elena; Beckles, Denise M; Guinan, Edward; Lehto, Harry J; Hallam, Steven J

    2011-04-01

    Pitch Lake in Trinidad and Tobago is a natural asphalt reservoir nourished by pitch seepage, a form of petroleum that consists of mostly asphaltines, from the surrounding oil-rich region. During upward seepage, pitch mixes with mud and gases under high pressure, and the lighter portion evaporates or is volatilized, which produces a liquid asphalt residue characterized by low water activity, recalcitrant carbon substrates, and noxious chemical compounds. An active microbial community of archaea and bacteria, many of them novel strains (particularly from the new Tar ARC groups), totaling a biomass of up to 10(7) cells per gram, was found to inhabit the liquid hydrocarbon matrix of Pitch Lake. Geochemical and molecular taxonomic approaches revealed diverse, novel, and deeply branching microbial lineages with the potential to mediate anaerobic hydrocarbon degradation processes in different parts of the asphalt column. In addition, we found markers for archaeal methane metabolism and specific gene sequences affiliated with facultative and obligate anaerobic sulfur- and nitrite-oxidizing bacteria. The microbial diversity at Pitch Lake was found to be unique when compared to microbial communities analyzed at other hydrocarbon-rich environments, which included Rancho Le Brea, a natural asphalt environment in California, USA, and an oil well and a mud volcano in Trinidad and Tobago, among other sites. These results open a window into the microbial ecology and biogeochemistry of recalcitrant hydrocarbon matrices and establish the site as a terrestrial analogue for modeling the biotic potential of hydrocarbon lakes such as those found on Saturn's largest moon Titan.

  8. Microbial Life in a Liquid Asphalt Desert

    NASA Astrophysics Data System (ADS)

    Schulze-Makuch, Dirk; Haque, Shirin; de Sousa Antonio, Marina Resendes; Ali, Denzil; Hosein, Riad; Song, Young C.; Yang, Jinshu; Zaikova, Elena; Beckles, Denise M.; Guinan, Edward; Lehto, Harry J.; Hallam, Steven J.

    2011-04-01

    Pitch Lake in Trinidad and Tobago is a natural asphalt reservoir nourished by pitch seepage, a form of petroleum that consists of mostly asphaltines, from the surrounding oil-rich region. During upward seepage, pitch mixes with mud and gases under high pressure, and the lighter portion evaporates or is volatilized, which produces a liquid asphalt residue characterized by low water activity, recalcitrant carbon substrates, and noxious chemical compounds. An active microbial community of archaea and bacteria, many of them novel strains (particularly from the new Tar ARC groups), totaling a biomass of up to 107 cells per gram, was found to inhabit the liquid hydrocarbon matrix of Pitch Lake. Geochemical and molecular taxonomic approaches revealed diverse, novel, and deeply branching microbial lineages with the potential to mediate anaerobic hydrocarbon degradation processes in different parts of the asphalt column. In addition, we found markers for archaeal methane metabolism and specific gene sequences affiliated with facultative and obligate anaerobic sulfur- and nitrite-oxidizing bacteria. The microbial diversity at Pitch Lake was found to be unique when compared to microbial communities analyzed at other hydrocarbon-rich environments, which included Rancho Le Brea, a natural asphalt environment in California, USA, and an oil well and a mud volcano in Trinidad and Tobago, among other sites. These results open a window into the microbial ecology and biogeochemistry of recalcitrant hydrocarbon matrices and establish the site as a terrestrial analogue for modeling the biotic potential of hydrocarbon lakes such as those found on Saturn's largest moon Titan.

  9. Systematic mining of generally recognized as safe (GRAS) flavor chemicals for bioactive compounds.

    PubMed

    Martinez-Mayorga, Karina; Peppard, Terry L; López-Vallejo, Fabian; Yongye, Austin B; Medina-Franco, José L

    2013-08-07

    Bioactive food compounds can be both therapeutically and nutritionally relevant. Screening strategies are widely employed to identify bioactive compounds from edible plants. Flavor additives contained in the so-called FEMA GRAS (generally recognized as safe) list of approved flavoring ingredients is an additional source of potentially bioactive compounds. This work used the principles of molecular similarity to identify compounds with potential mood-modulating properties. The ability of certain GRAS molecules to inhibit histone deacetylase-1 (HDAC1), proposed as an important player in mood modulation, was assayed. Two GRAS chemicals were identified as HDAC1 inhibitors in the micromolar range, results similar to what was observed for the structurally related mood prescription drug valproic acid. Additional studies on bioavailability, toxicity at higher concentrations, and off-target effects are warranted. The methodology described in this work could be employed to identify potentially bioactive flavor chemicals present in the FEMA GRAS list.

  10. Microbial enhanced oil recovery research. [Peptides

    SciTech Connect

    Sharma, M.M.; Georgiou, G. )

    1992-01-01

    The surface active lipopeptide produced by Bacillus licheniformis JF-2 was isolated to near apparent homogeneity. NMR experiments revealed that this compound consists of a heptapeptide with an amino acid sequence similar to surfactin and a heterogeneous fatty acid consisting of the normal-, anteiso-, and iso- branched isomers. The surface activity of the B. licheniformis JF-2 surfactant was shown to depend on the presence of fermentation products and is strongly affected by the pH. Under conditions of optimal salinity and pH the interfacial tension against decane was 6 [times] 10[sup 3] mN/m which is one of the lowest values ever obtained with a microbial surfactant. Microbial compounds which exhibit particularly high surface activity are classified as biosurfactants. Microbial biosurfactants include a wide variety of surface and interfacially active compounds, such as glycolipids, lipopeptides polysaccharideprotein complexes, phospholipids, fatty acids and neutral lipids. Biosurfactants are easily biodegradable and thus are particularly suited for environmental applications such as bioremediation and the dispersion of oil spills. Bacillus licheniformis strain JF-2 has been shown to be able to grow and produce a very effective biosurfactant under both aerobic and anaerobic conditions and in the presence of high salt concentrations. The production of biosurfactants in anaerobic, high salt environments is potentially important for a variety of in situ applications such as microbial enhanced oil recovery. As a first step towards evaluating the commercial utility of the B. licheniformis JF-2 surfactant, we isolated t-he active. compound from the culture supernatant, characterized its chemical structure and investigated its phase behavior. We found that the surface activity of the surfactant is strongly dependent on the pH of the aqueous. phase. This may be important for the biological function of the surfactant and is of interest for several applications in surfactancy.

  11. 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

  12. 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.

  13. Multipurpose Compound

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Specially formulated derivatives of an unusual basic compound known as Alcide may be the answer to effective treatment and prevention of the disease bovine mastitis, a bacterial inflammation of a cow's mammary gland that results in loss of milk production and in extreme cases, death. Manufactured by Alcide Corporation the Alcide compound has killed all tested bacteria, virus and fungi, shortly after contact, with minimal toxic effects on humans or animals. Alcide Corporation credits the existence of the mastitis treatment/prevention products to assistance provided the company by NERAC, Inc.

  14. Microbial Factories for the Production of Benzylisoquinoline Alkaloids.

    PubMed

    Narcross, Lauren; Fossati, Elena; Bourgeois, Leanne; Dueber, John E; Martin, Vincent J J

    2016-03-01

    Benzylisoquinoline alkaloids (BIAs) are a family of ∼2500 alkaloids with both potential and realized pharmaceutical value, including most notably the opiates such as codeine and morphine. Only a few BIAs accumulate readily in plants, which limits the pharmaceutical potential of the family. Shifting BIA production to microbial sources could provide a scalable and flexible source of these compounds in the future. This review details the current status of microbial BIA synthesis and derivatization, including rapid developments in the past 6 months culminating in the synthesis of opioids from glucose in a microbial host.

  15. Engineering microbial factories for synthesis of value-added products

    PubMed Central

    Du, Jing; Shao, Zengyi; Zhao, Huimin

    2011-01-01

    Microorganisms have become an increasingly important platform for the production of drugs, chemicals, and biofuels from renewable resources. Advances in protein engineering, metabolic engineering, and synthetic biology enable redesigning microbial cellular networks and fine-tuning physiological capabilities, thus generating industrially viable strains for the production of natural and unnatural value-added compounds. In this review, we describe the recent progress on engineering microbial factories for synthesis of valued-added products including alkaloids, terpenoids, flavonoids, polyketides, non-ribosomal peptides, biofuels, and chemicals. Related topics on lignocellulose degradation, sugar utilization, and microbial tolerance improvement will also be discussed. PMID:21526386

  16. Microbial-Catalyzed Biotransformation of Multifunctional Triterpenoids Derived from Phytonutrients

    PubMed Central

    Shah, Syed Adnan Ali; Tan, Huey Ling; Sultan, Sadia; Mohd Faridz, Muhammad Afifi Bin; Mohd Shah, Mohamad Azlan Bin; Nurfazilah, Sharifah; Hussain, Munawar

    2014-01-01

    Microbial-catalyzed biotransformations have considerable potential for the generation of an enormous variety of structurally diversified organic compounds, especially natural products with complex structures like triterpenoids. They offer efficient and economical ways to produce semi-synthetic analogues and novel lead molecules. Microorganisms such as bacteria and fungi could catalyze chemo-, regio- and stereospecific hydroxylations of diverse triterpenoid substrates that are extremely difficult to produce by chemical routes. During recent years, considerable research has been performed on the microbial transformation of bioactive triterpenoids, in order to obtain biologically active molecules with diverse structures features. This article reviews the microbial modifications of tetranortriterpenoids, tetracyclic triterpenoids and pentacyclic triterpenoids. PMID:25003642

  17. Engineering microbial factories for synthesis of value-added products.

    PubMed

    Du, Jing; Shao, Zengyi; Zhao, Huimin

    2011-08-01

    Microorganisms have become an increasingly important platform for the production of drugs, chemicals, and biofuels from renewable resources. Advances in protein engineering, metabolic engineering, and synthetic biology enable redesigning microbial cellular networks and fine-tuning physiological capabilities, thus generating industrially viable strains for the production of natural and unnatural value-added compounds. In this review, we describe the recent progress on engineering microbial factories for synthesis of valued-added products including alkaloids, terpenoids, flavonoids, polyketides, non-ribosomal peptides, biofuels, and chemicals. Related topics on lignocellulose degradation, sugar utilization, and microbial tolerance improvement will also be discussed.

  18. Electricity generation in a microbial fuel cell with a microbially catalyzed cathode.

    PubMed

    Zhang, Jin-Na; Zhao, Qing-Liang; Aelterman, Peter; You, Shi-Jie; Jiang, Jun-Qiu

    2008-10-01

    A microbial fuel cell using aerobic microorganisms as the cathodic catalysts is described. By using anaerobic sludge in the anode and aerobic sludge in the cathode as inocula, the microbial fuel cell could be started up after a short lag time of 9 days, generating a stable voltage of 0.324 V (R (ex) = 500 Omega). At an aeration rate of 300 ml min(-1) in the cathode, a maximum volumetric power density of up to 24.7 W m(-3) (117.2 A m(-3)) was reached. This research demonstrates an economic system for recovering electrical energy from organic compounds.

  19. [Methods of the multivariate statistical analysis of so-called polyetiological diseases using the example of coronary heart disease].

    PubMed

    Lifshits, A M

    1979-01-01

    General characteristics of the multivariate statistical analysis (MSA) is given. Methodical premises and criteria for the selection of an adequate MSA method applicable to pathoanatomic investigations of the epidemiology of multicausal diseases are presented. The experience of using MSA with computors and standard computing programs in studies of coronary arteries aterosclerosis on the materials of 2060 autopsies is described. The combined use of 4 MSA methods: sequential, correlational, regressional, and discriminant permitted to quantitate the contribution of each of the 8 examined risk factors in the development of aterosclerosis. The most important factors were found to be the age, arterial hypertension, and heredity. Occupational hypodynamia and increased fatness were more important in men, whereas diabetes melitus--in women. The registration of this combination of risk factors by MSA methods provides for more reliable prognosis of the likelihood of coronary heart disease with a fatal outcome than prognosis of the degree of coronary aterosclerosis.

  20. [Iritis following cataract operations. Historical retrospective with critical comments on a so-called "toxic lens" syndrome].

    PubMed

    Wenzel, M

    1990-06-01

    Postoperative inflammation is one of the oldest complications of cataract surgery. It was described by the Indian Susruta as early as 500 BC. Following the introduction of cataract extraction by Daviel in 1745, these operations attracted increasing interest. In 1786 de Wenzel distinguished two types of postoperative inflammation. In the dangerous type there was involvement of the entire eye and severe pain; in the benign type, which began in the first few postoperative days, the conjunctiva and lids were not involved, and even if hypopyon developed there was no severe pain. During the 19th century, the possible causes of the benign type of iritis were discussed, including infection, phacoanaphylaxis, trauma, toxicity of irrigation solutions etc. In the early days of implantation of intraocular lenses, from 1949 onward, postoperative inflammation was common. However, it was not until 1980 that the term "toxic lens syndrome" was introduced. The clinical descriptions do not differ much from other descriptions of benign iritis published during the last 200 years. Therefore, it does not seem that there is any great advantage to be gained by using this new term.

  1. [Clinical signs, diagnostic approach and therapy for the so-called ovarian remnant syndrome in the bitch].

    PubMed

    Günzel-Apel, A-R; Buschhaus, J; Urhausen, C; Masal, C; Wolf, K; Meyer-Lindenberg, A; Piechotta, M; Beyerbach, M; Schoon, H-A

    2012-01-01

    The ovarian remnant syndrome arises as a consequence of incomplete ovariectomy or ovariohysterectomy. Remnant ovarian tissue which has been left mostly unintentionally in the bitch may show endocrine activity a few weeks to several years after surgery, provoking a variety of clinical signs. The majority of affected bitches return to heat, in other cases signs of pseudopregnancy and endometritis may be observed. Occasionally, bitches with unclear clinical signs are presented with the suspicion of an inactive ovarian remnant. The following article intends to place the origin of the ovarian remnant syndrome into a factual context regarding the responsibility of the veterinarian and to demonstrate a reasonable diagnostic procedure according to the respective clinical signs. In this regard, the clinical-gynaecological examination, including vaginal cytology, must receive high priority, with the addition of progesterone analysis in peripheral blood plasma or serum if required. Using these combined diagnostic tools, ovarian remnants in stages of endocrine activity (follicular and luteal phases as well as cystic or tumourous ovarian tissue) can be easily unequivocally diagnosed. The application of a GnRH-stimulation test is only reasonable in bitches in which clinical signs are missing. In this context, the usefulness of semi-quantitative LH-assays is also discussed.

  2. Unseen WEIRD Assumptions: The So-Called Language Gap Discourse and Ideologies of Language, Childhood, and Learning

    ERIC Educational Resources Information Center

    Blum, Susan D.

    2017-01-01

    Claiming to rely on "science," many well-intentioned "experts" offer advice on how to "close the gap"--word gap, language gap, achievement gap--between disadvantaged and advantaged children. Based on both research and personal experience, this advice promises magic solutions to apparently complex and intractable…

  3. A CHEMO-BIOLOGICAL STUDY OF THE RELATIONS OF PEPSIN TO SO-CALLED ANTI-PEPSIN

    PubMed Central

    Hamburger, Walter W.

    1911-01-01

    1. Fresh and inactivated animal serum under proper conditions will bind pepsin quantitatively in weak acid solution and will prevent it from digesting proteid even after the addition of free hydrochloric acid in excess. 2. This binding and inactivation of pepsin cannot be considered as due to a specific anti-pepsin. 3. The phenomenon has been named pepsin deviation in analogy with the deviation described for other ferments, notably trypsin. 4. The ability of animal serum to deviate pepsin has been responsible for most, if not all, of the published accounts of anti-pepsin. 5. By the use of a technique elaborated to control pepsin deviation, it has been found impossible to demonstrate normal anti-pepsin in the blood serum of the dog, cat, guinea pig, beef, horse, rabbit, and of man. PMID:19867495

  4. Specific amplification of bacterial DNA by optimized so-called universal bacterial primers in samples rich of plant DNA.

    PubMed

    Dorn-In, Samart; Bassitta, Rupert; Schwaiger, Karin; Bauer, Johann; Hölzel, Christina S

    2015-06-01

    Universal primers targeting the bacterial 16S-rRNA-gene allow quantification of the total bacterial load in variable sample types by qPCR. However, many universal primer pairs also amplify DNA of plants or even of archaea and other eukaryotic cells. By using these primers, the total bacterial load might be misevaluated, whenever samples contain high amounts of non-target DNA. Thus, this study aimed to provide primer pairs which are suitable for quantification and identification of bacterial DNA in samples such as feed, spices and sample material from digesters. For 42 primers, mismatches to the sequence of chloroplasts and mitochondria of plants were evaluated. Six primer pairs were further analyzed with regard to the question whether they anneal to DNA of archaea, animal tissue and fungi. Subsequently they were tested with sample matrix such as plants, feed, feces, soil and environmental samples. To this purpose, the target DNA in the samples was quantified by qPCR. The PCR products of plant and feed samples were further processed for the Single Strand Conformation Polymorphism method followed by sequence analysis. The sequencing results revealed that primer pair 335F/769R amplified only bacterial DNA in samples such as plants and animal feed, in which the DNA of plants prevailed.

  5. [So-called humero-scapular periarthropathy--classification and analysis based on 1,266 cases].

    PubMed

    Hedtmann, A; Fett, H

    1989-01-01

    1266 cases of Periarthropathia humeroscapularis (PHS) were analyzed according to their clinical and sonographic findings. We found in 32.8% a PHS simplex (simple tendinitis), in 12.6% a PHS adhäsiva (stiff and painful shoulder with intact cuff), in 17% a PHS calcarea (calcareous tendinitis) and in 33.3% a PHS destructiva (rotator cuff lesions). Isolated tendinitis of long head of biceps was rare (0.7%). Frozen shoulder (adhaesive capsulitis) was differentiated from PHS adhäsiva and accounted of 1.9%. 33.3% of frozen shoulder patients suffered from type I Diabetes mellitus. Women were more affected by PHS calcarea and Frozen Shoulder. The average age of patients with PHS adhäsiva and PHS destructiva was definitely higher than that of PHS simplex cases. PHS adhäsiva and Frozen Shoulder had an even distribution of affected sides, whereas the right side was favoured from 1.7:1 (PHS calcarea and PHS destructiva) to 3.5:1 (isolated bicipital tendinitis). Cases of rotator cuff tears were stiff in 33.7%, and had active limited motion (pseudoparalysis) in 28.5%.

  6. [Paradigm shift in the so-called "certification of medical fitness" for the recruitment of new civil servants].

    PubMed

    Lange, R

    2014-04-01

    In actual jurisdiction the Federal Administrative Court has substantially reduced the standard of "health ability" for civil servants who shall be newly employed. That means for the regulated official pre-employment medical examination that in critical cases a recommendation for non-employment will be more rarely considered in the lack of valid, i. e., selective scientific principles. Thereby the formerly pursued selection effect based on civil service law mainly will not apply in the future. Even though the widely opened approach to the civil servant status might be a favour for interested handicapped persons, the following impacts on official-organisational as well as fiscal aspects (governmental aid, pension- burden) can be difficultly foreseen. Hence, in the future the official pre-employment medical -examination will develop an increasing focus on advices about restrictions of assignment possibly having to be considered for admitted candidates.

  7. [Sudden cardiac arrest in Italian sports facilities in 2015: epidemiological implications of the so-called "Balduzzi decree"].

    PubMed

    Zorzi, Alessandro; Susana, Angela; Spadotto, Veronica; Cacciavillani, Luisa; Corrado, Domenico

    2016-11-01

    Under the Italian Law "Legge Balduzzi", which was issued after the sudden cardiac death of professional athletes Pier Mario Morosini and Vigor Bovolenta in 2012, the presence of an automated external defibrillator (AED) and personnel trained to perform cardiopulmonary resuscitation must be available in every Italian sports facility from 2016. In 2015 the national and local press reported 123 cases of sudden cardiac arrests (SCA) occurring in Italian sport facilities, corresponding to an estimated ≈0.2-0.4% of all SCA and to ≈0.6-1.2% of SCA in public places. The majority of SCA victims were males (93%) and >35 years old (88%, median age 50 years). On the basis of the report of the event on the press, the rate of return of spontaneous circulation was 62% when an AED was used before emergency medical system arrival versus 9% when no bystander cardiopulmonary resuscitation or AED use by lay rescuers was mentioned. These data demonstrated that the Law has the potential to increase the survival to SCA in athletes; however, limiting the obligation of the presence of an AED only to sports facilities is not enough to decrease significantly the incidence of SCA in the general population.

  8. Perfluorinated Compounds

    EPA Science Inventory

    Perfluorinated compounds such as the perfluoroalkyl acids (PFAAs) and their derivatives are important man-made chemicals that have wide consumer and industrial applications. They are relatively contemporary chemicals, being in use only since the 1950s, and until recently, have be...

  9. Valproic Acid Induces Antimicrobial Compound Production in Doratomyces microspores

    PubMed Central

    Zutz, Christoph; Bacher, Markus; Parich, Alexandra; Kluger, Bernhard; Gacek-Matthews, Agnieszka; Schuhmacher, Rainer; Wagner, Martin; Rychli, Kathrin; Strauss, Joseph

    2016-01-01

    One of the biggest challenges in public health is the rising number of antibiotic resistant pathogens and the lack of novel antibiotics. In recent years there is a rising focus on fungi as sources of antimicrobial compounds due to their ability to produce a large variety of bioactive compounds and the observation that virtually every fungus may still contain yet unknown so called “cryptic,” often silenced, compounds. These putative metabolites could include novel bioactive compounds. Considerable effort is spent on methods to induce production of these “cryptic” metabolites. One approach is the use of small molecule effectors, potentially influencing chromatin landscape in fungi. We observed that the supernatant of the fungus Doratomyces (D.) microsporus treated with valproic acid (VPA) displayed antimicrobial activity against Staphylococcus (S.) aureus and two methicillin resistant clinical S. aureus isolates. VPA treatment resulted in enhanced production of seven antimicrobial compounds: cyclo-(L-proline-L-methionine) (cPM), p-hydroxybenzaldehyde, cyclo-(phenylalanine-proline) (cFP), indole-3-carboxylic acid, phenylacetic acid (PAA) and indole-3-acetic acid. The production of the antimicrobial compound phenyllactic acid was exclusively detectable after VPA treatment. Furthermore three compounds, cPM, cFP, and PAA, were able to boost the antimicrobial activity of other antimicrobial compounds. cPM, for the first time isolated from fungi, and to a lesser extent PAA, are even able to decrease the minimal inhibitory concentration of ampicillin in MRSA strains. In conclusion we could show in this study that VPA treatment is a potent tool for induction of “cryptic” antimicrobial compound production in fungi, and that the induced compounds are not exclusively linked to the secondary metabolism. Furthermore this is the first discovery of the rare diketopiperazine cPM in fungi. Additionally we could demonstrate that cPM and PAA boost antibiotic activity

  10. Metabolite generation via microbial biotransformations with Actinomycetes: rapid screening for active strains and biosynthesis of important human metabolites of two development-stage compounds, 5-[(5S,9R)-9-(4-cyanophenyl)-3-(3,5-dichlorophenyl)-1-methyl-2,4-dioxo-1,3,7-triazaspiro[4.4]non7-yl-methyl]-3-thiophenecarboxylic acid (BMS-587101) and dasatinib.

    PubMed

    Li, Wenying; Josephs, Jonathan L; Skiles, Gary L; Humphreys, W Griffith

    2008-04-01

    The enzymes present in many microbial strains are capable of carrying out a variety of biotransformations when presented with drug-like molecules. Although the enzymes responsible for the biotransformations are not well characterized, microbial strains can often be found that produce metabolites identical to those found in mammalian systems. However, traditional screening for microbial strains that produce metabolites of interest is done with many labor intensive steps that include multiple shake flasks and many manual manipulations, which hinder the application of these techniques in drug metabolite preparation. A 24-well microtiter plate screening system was developed for rapid screening of actinomycetes strains for their ability to selectively produce metabolites of interest. The utility of this system was first demonstrated with the well characterized cytochrome P450 substrate diclofenac. Subsequently, the use of this system allowed the rapid identification of several actinomycetes strains that were capable of converting two drug candidates under development, 5-[(5S,9R)-9-(4-cyanophenyl)-3-(3,5-dichlorophenyl)-1-methyl-2,4-dioxo-1,3,7-triazaspiro[4.4]non7-yl-methyl]-3-thiophenecarboxylic acid and N-(2-chloro-6-methylphenyl)-2-[[6-[4-(2-hydroxyethyl)-1-piperazinyl)]-2-methyl-4-pyrimidinyl]amino)]-1,3-thiazole-5-carboxamide (dasatinib, Sprycel, BMS-345825), to mammalian metabolites of interest. Milligram quantities of the metabolites were then prepared by scaling-up the microbial biotransformation reactions. These quantities were sufficient for initial characterization, such as testing for pharmacological activity and use as analytical standards, prior to the availability of authentic chemically synthesized compounds.

  11. Conditioning biomass for microbial growth

    DOEpatents

    Bodie, Elizabeth A; England, George

    2015-03-31

    The present invention relates to methods for improving the yield of microbial processes that use lignocellulose biomass as a nutrient source. The methods comprise conditioning a composition comprising lignocellulose biomass with an enzyme composition that comprises a phenol oxidizing enzyme. The conditioned composition can support a higher rate of growth of microorganisms in a process. In one embodiment, a laccase composition is used to condition lignocellulose biomass derived from non-woody plants, such as corn and sugar cane. The invention also encompasses methods for culturing microorganisms that are sensitive to inhibitory compounds in lignocellulose biomass. The invention further provides methods of making a product by culturing the production microorganisms in conditioned lignocellulose biomass.

  12. Microbial fuel cell treatment of fuel process wastewater

    DOEpatents

    Borole, Abhijeet P; Tsouris, Constantino

    2013-12-03

    The present invention is directed to a method for cleansing fuel processing effluent containing carbonaceous compounds and inorganic salts, the method comprising contacting the fuel processing effluent with an anode of a microbial fuel ell, the anode containing microbes thereon which oxidatively degrade one or more of the carbonaceous compounds while producing electrical energy from the oxidative degradation, and directing the produced electrical energy to drive an electrosorption mechanism that operates to reduce the concentration of one or more inorganic salts in the fuel processing effluent, wherein the anode is in electrical communication with a cathode of the microbial fuel cell. The invention is also directed to an apparatus for practicing the method.

  13. Modes of Action of Microbially-Produced Phytotoxins

    PubMed Central

    Duke, Stephen O.; Dayan, Franck E.

    2011-01-01

    Some of the most potent phytotoxins are synthesized by microbes. A few of these share molecular target sites with some synthetic herbicides, but many microbial toxins have unique target sites with potential for exploitation by the herbicide industry. Compounds from both non-pathogenic and pathogenic microbes are discussed. Microbial phytotoxins with modes of action the same as those of commercial herbicides and those with novel modes of action of action are covered. Examples of the compounds discussed are tentoxin, AAL-toxin, auscaulitoxin aglycone, hydantocidin, thaxtomin, and tabtoxin. PMID:22069756

  14. 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

  15. Nitrogen cycle in microbial mats: completely unknown?

    NASA Astrophysics Data System (ADS)

    Coban, O.; Bebout, B.

    2015-12-01

    Microbial mats are thought to have originated around 3.7 billion years ago, most likely in the areas around submarine hydrothermal vents, which supplied a source of energy in the form of reduced chemical species from the Earth's interior. Active hydrothermal vents are also believed to exist on Jupiter's moon Europa, Saturn's moon Enceladus, and on Mars, earlier in that planet's history. Microbial mats have been an important force in the maintenance of Earth's ecosystems and the first photosynthesis was also originated there. Microbial mats are believed to exhibit most, if not all, biogeochemical processes that exist in aquatic ecosystems, due to the presence of different physiological groups of microorganisms therein. While most microbially mediated biogeochemical transformations have been shown to occur within microbial mats, the nitrogen cycle in the microbial mats has received very little study in spite of the fact that nitrogen usually limits growth in marine environments. We will present the first results in the determination of a complete nitrogen budget for a photosynthetic microbial mat. Both in situ sources and sinks of nitrogen in photosynthetic microbial mats are being measured using stable isotope techniques. Our work has a particular focus on recently described, but poorly understood, processes, e.g., anammox and dissimilatory nitrate reduction, and an emphasis on understanding the role that nitrogen cycling may play in generating biogenic nitrogen isotopic signatures and biomarker molecules. Measurements of environmental controls on nitrogen cycling should offer insight into the nature of co-evolution of these microbial communities and their planets of origin. Identifying the spatial (microscale) as well as temporal (diel and seasonal) distribution of nitrogen transformations, e.g., rates of nitrification and denitrification, within mats, particularly with respect to the distribution of photosynthetically-produced oxygen, is anticipated. The results

  16. Pyrogenic organic matter can alter microbial communication

    NASA Astrophysics Data System (ADS)

    Masiello, Caroline; Gao, Xiaodong; Cheng, Hsiao-Ying; Silberg, Jonathan

    2016-04-01

    Soil microbes communicate with each other to manage a large range of processes that occur more efficiently when microbes are able to act simultaneously. This coordination occurs through the continuous production of signaling compounds that are easily diffused into and out of cells. As the number of microbes in a localized environment increases, the internal cellular concentration of these signaling compounds increases, and when a threshold concentration is reached, gene expression shifts, leading to altered (and coordinated) microbial behaviors. Many of these coordinated behaviors have biogeochemically important outcomes. For example, methanogenesis, denitrification, biofilm formation, and the development of plant-rhizobial symbioses are all regulated by a simple class of cell-cell signaling molecules known as acyl homoserine lactones (AHLs). Pyrogenic organic matter in soils can act to disrupt microbial communication through multiple pathways. In the case of AHLs, charcoal's very high surface area can sorb these signaling compounds, preventing microbes from detecting each others' presence (Masiello et al., 2014). In addition, the lactone ring in AHLs is vulnerable to pH increases accompanying PyOM inputs, with soil pH values higher than 7-8 leading to ring opening and compound destabilization. Different microbes use different classes of signaling compounds, and not all microbial signaling compounds are pH-vulnerable. This implies that PyOM-driven pH increases may trigger differential outcomes for Gram negative bacteria vs fungi, for example. A charcoal-driven reduction in microbes' ability to detect cell-cell communication compounds may lead to a shift in the ability of microbes to participate in key steps of C and N cycling. For example, an increase in an archaeon-specific AHL has been shown to lead to a cascade of metabolic processes that eventually results in the upregulation of CH4 production (Zhang et al., 2012). Alterations in similar AHL compounds leads to

  17. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2003-01-01

    Seawater and natural brines accounted for about 60 percent of U.S. magnesium compounds production during 2002. Dead-burned and caustic-calcined magnesias were recovered from seawater by Premier Chemicals in Florida. They were also recovered from well brines in Michigan by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And they were recovered from magnesite in Nevada by Premier Chemicals.

  18. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2006-01-01

    In 2005, seawater and natural brines accounted for 51% of US magnesium compounds production. World magnesia production was estimated to be 14.5 Mt. Most of the production came from China, North Korea, Russia and Turkey. Although no specific production figures are available, Japan and the United States are estimated to account for almost one-half of the world's capacity from seawater and brines.

  19. Spectroscopic analysis of phenolic compounds for food and feed formulations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phenolic compounds exhibit several bioactive properties including anti-oxidant, anti-microbial, and anti-fungal characteristics with potential applications as additives in functional food and feed formulations. Phenolic compounds occur in plants as secondary metabolites and may be recovered as a co-...

  20. QMRAspot: a tool for Quantitative Microbial Risk Assessment from surface water to potable water.

    PubMed

    Schijven, Jack F; Teunis, Peter F M; Rutjes, Saskia A; Bouwknegt, Martijn; de Roda Husman, Ana Maria

    2011-11-01

    In the Netherlands, a health based target for microbially safe drinking water is set at less than one infection per 10,000 persons per year. For the assessment of the microbial safety of drinking water, Dutch drinking water suppliers must conduct a Quantitative Microbial Risk Assessment (QMRA) at least every three years for the so-called index pathogens enterovirus, Campylobacter, Cryptosporidium and Giardia. In order to collect raw data in the proper format and to automate the process of QMRA, an interactive user-friendly computational tool, QMRAspot, was developed to analyze and conduct QMRA for drinking water produced from surface water. This paper gives a description of the raw data requirements for QMRA as well as a functional description of the tool. No extensive prior knowledge about QMRA modeling is required by the user, because QMRAspot provides guidance to the user on the quantity, type and format of raw data and performs a complete analysis of the raw data to yield a risk outcome for drinking water consumption that can be compared with other production locations, a legislative standard or an acceptable health based target. The uniform approach promotes proper collection and usage of raw data and, warrants quality of the risk assessment as well as enhances efficiency, i.e., less time is required. QMRAspot may facilitate QMRA for drinking water suppliers worldwide. The tool aids policy makers and other involved parties in formulating mitigation strategies, and prioritization and evaluation of effective preventive measures as integral part of water safety plans.

  1. Resistant Microbial Cooccurrence Patterns Inferred by Network Topology

    PubMed Central

    Peura, Sari; Bertilsson, Stefan; Jones, Roger I.

    2015-01-01

    Although complex cooccurrence patterns have been described for microbes in natural communities, these patterns have scarcely been interpreted in the context of ecosystem functioning and stability. Here we constructed networks from species cooccurrences between pairs of microorganisms which were extracted from five individual aquatic time series, including a dystrophic and a eutrophic lake as well as an open ocean site. The resulting networks exhibited higher clustering coefficients, shorter path lengths, and higher average node degrees and levels of betweenness than those of random networks. Moreover, simulations demonstrated that taxa with a large number of cooccurrences and placement at convergence positions in the network, so-called “hubs” and “bottlenecks,” confer resistance against random removal of “taxa.” Accordingly, we refer to cooccurrences at convergence positions as system-relevant interdependencies, as they, like hubs and bottlenecks, determine network topology. These topology features of the cooccurrence networks point toward microbial community dynamics being resistant over time and thus could provide indicators for the state of ecosystem stability. PMID:25576616

  2. Engineering microbial chemical factories to produce renewable “biomonomers”

    PubMed Central

    Adkins, Jake; Pugh, Shawn; McKenna, Rebekah; Nielsen, David R.

    2012-01-01

    By applying metabolic engineering tools and strategies to engineer synthetic enzyme pathways, the number and diversity of commodity and specialty chemicals that can be derived directly from renewable feedstocks is rapidly and continually expanding. This of course includes a number of monomer building-block chemicals that can be used to produce replacements to many conventional plastic materials. This review aims to highlight numerous recent and important advancements in the microbial production of these so-called “biomonomers.” Relative to naturally-occurring renewable bioplastics, biomonomers offer several important advantages, including improved control over the final polymer structure and purity, the ability to synthesize non-natural copolymers, and allowing products to be excreted from cells which ultimately streamlines downstream recovery and purification. To highlight these features, a handful of biomonomers have been selected as illustrative examples of recent works, including polyamide monomers, styrenic vinyls, hydroxyacids, and diols. Where appropriate, examples of their industrial penetration to date and end-product uses are also highlighted. Novel biomonomers such as these are ultimately paving the way toward new classes of renewable bioplastics that possess a broader diversity of properties than ever before possible. PMID:22969753

  3. 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.

  4. 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...

  5. Increased electrical output when a bacterial ABTS oxidizer is used in a microbial fuel cell

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microbial fuel cells (MFCs) are a technology that provides electrical energy from the microbial oxidation of organic compounds. Most MFCs use oxygen as the oxidant in the cathode chamber. The present study examined the formation in culture of an unidentified bacterial oxidant and investigated the ...

  6. Design of multifunctional compounds for cardiovascular disease: from natural scaffolds to "classical" multitarget approach.

    PubMed

    Bisi, A; Gobbi, S; Belluti, F; Rampa, A

    2013-01-01

    Cardiovascular disease represents the main cause of death worldwide. Novel therapies to reduce elevated blood pressure and treat resistant hypertension, to consequently reduce the associated cardiovascular risk factors, are still required. Among the different strategies commonly used in medicinal chemistry to develop new molecules, the synthesis of multitarget/hybrid compounds combining two or more pharmacophore groups targeting simultaneously selected factors involved in cardiovascular diseases, has gained increasing interest. This review will focus on the most recent literature on multifunctional cardiovascular drugs, paying particular attention on hybrid compounds bearing natural scaffolds, considering that compounds derived from medicinal extracts are generally appealing for the medicinal chemist as they often bear the so-called "privileged structures". Moreover, taking into account many excellent reviews dealing with multitarget cardiovascular drugs published in the last few years, mainly devoted to RAAS inhibition and/or NO donors hybrid drugs, herein the most significant results obtained and the benefits and limitations of these approaches will be highlighted.

  7. Simultaneous complexation of organic compounds and heavy metals by a modified cyclodextrin

    SciTech Connect

    Wang, X.; Brusseau, M.L.

    1995-10-01

    The cleanup of contaminated soil and groundwater at hazardous waste sites has become a major focus of research and policy debate. A major factor complicating the cleanup of many sites is the cooccurrence of organic compounds and heavy metals, the so-called mixed wastes. We investigated the ability of a modified cyclodextrin to simultaneously complex low-polarity organic compounds and heavy metals. The results of the experiments showed that carboxymethyl-{beta}-cyclodextrin could simultaneously increase the apparent aqueous solubilities of the selected organic compounds (anthracene, trichlorobenzene; biphenyl, and ODT) and complex with Cd{sup 2+}. This complexation was not significantly affected by changes in pH or by the presence of relatively high concentrations of Ca{sup 2+}. It is possible that this reagent can be used successfully to remediate hazardous waste sites contaminated by mixed wastes. 11 refs., 7 figs.

  8. Filtering promiscuous compounds in early drug discovery: is it a good idea?

    PubMed

    Senger, Mario R; Fraga, Carlos A M; Dantas, Rafael F; Silva, Floriano P

    2016-06-01

    The use of computational filters for excluding supposedly nonspecific and promiscuous compounds from chemical libraries is a controversial issue, because many drugs used in clinics today would never reach the market if these filters were applied. In part, this conflict could be caused by the paradigm: one-drug-one-target, even though it is widely agreed that drug action is a result of a complex network of biomolecular interactions. Therefore, the so-called pan assay interference compounds (PAINS) or promiscuous compounds could be in fact assay artifacts, false positives or, simply, bright chemical matter (BCM) composed of privileged scaffolds, as we propose here. Despite apparent promiscuity, BCM can be tailored into new and safe drugs after overcoming selectivity criteria.

  9. A survey of phytotoxic microbial and plant metabolites as potential natural products for pest management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytotoxic microbial metabolites produced by certain phytopathogenic fungi and bacteria and a group of a phytotoxic plant metabolites including Amayllidaceae alkaloids and some derivatives of these compounds were evaluated for algicide, bactericide, insecticide, fungicide, and herbicide activities i...

  10. Dual active ionic liquids and organic salts for inhibition of microbially influenced corrosion.

    PubMed

    Seter, Marianne; Thomson, Melanie J; Stoimenovski, Jelena; MacFarlane, Douglas R; Forsyth, Maria

    2012-06-18

    We describe a series of novel compounds designed to combat the bacterial growth that leads to microbially induced corrosion on steel in the marine environment. A synergistic effect of the ionic components in these dual active organic salts is demonstrated.

  11. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2002-01-01

    Seawater and natural brines accounted for about 60% of US magnesium compounds production in 2001. Dead-burned and caustic-calcined magnesias were recovered from seawater in Florida by Premier Chemicals. They were also recovered from Michigan well brines by Dow Chemical, Martin Marietta Magnesia Specialties and Rohm & Haas. And Premier Chemicals recovered dead-burned and caustic-calcined magnesias from magnesite in Nevada. Reilly Industries and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah.

  12. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2011-01-01

    Seawater and natural brines accounted for about 54 percent of U.S. magnesium compounds production in 2010. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash-Wendover and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its operation mentioned above.

  13. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2010-01-01

    Seawater and natural brines accounted for about 40 percent of U.S. magnesium compounds production in 2009. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Chemicals in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Chemicals. Intrepid Potash-Wendover, and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma in Delaware and Premier Chemicals in Florida, and by Martin Marietta from its operation mentioned above.

  14. Allelopathy-mediated Competition in Microbial Mats from Antarctic Lakes.

    PubMed

    Slattery, Marc; Lesser, Michael P

    2017-02-18

    Microbial mats are vertically stratified communities that host a complex consortium of microorganisms, dominated by cyanobacteria, that compete for available nutrients and environmental niches, within these extreme habitats. The Antarctic Dry Valleys near McMurdo Sound include a series of lakes within the drainage basin that are bisected by glacial traverses. These lakes are traditionally independent, but recent increases in glacial melting have allowed two lakes (Chad and Hoare) to become connected by a meltwater stream. Microbial mats were collected from these lakes, and cultured under identical conditions at the McMurdo Station laboratory. Replicate pairings of the microbial mats exhibited consistent patterns of growth inhibition indicative of competitive dominance. Natural products were extracted from the microbial mats, and a disc diffusion assay was utilized to show that allelochemical compounds mediate competitive interactions. Both microscopy and 16S rRNA sequencing show that these mats contain significant populations of cyanobacteria known to produce allelochemicals. Two compounds were isolated from these microbial mats that might be important in the chemical ecology of these psychrophiles. In other disc:mat pairings, including extract versus mat of origin, the allelochemicals exhibited no effect. Taken together, these results indicate that Antarctic lake microbial mats can compete via allelopathy.

  15. Ecogenomics of microbial communities in bioremediation of chlorinated contaminated sites

    PubMed Central

    Maphosa, Farai; Lieten, Shakti H.; Dinkla, Inez; Stams, Alfons J.; Smidt, Hauke; Fennell, Donna E.

    2012-01-01

    Organohalide compounds such as chloroethenes, chloroethanes, and polychlorinated benzenes are among the most significant pollutants in the world. These compounds are often found in contamination plumes with other pollutants such as solvents, pesticides, and petroleum derivatives. Microbial bioremediation of contaminated sites, has become commonplace whereby key processes involved in bioremediation include anaerobic degradation and transformation of these organohalides by organohalide respiring bacteria and also via hydrolytic, oxygenic, and reductive mechanisms by aerobic bacteria. Microbial ecogenomics has enabled us to not only study the microbiology involved in these complex processes but also develop tools to better monitor and assess these sites during bioremediation. Microbial ecogenomics have capitalized on recent advances in high-throughput and -output genomics technologies in combination with microbial physiology studies to address these complex bioremediation problems at a system level. Advances in environmental metagenomics, transcriptomics, and proteomics have provided insights into key genes and their regulation in the environment. They have also given us clues into microbial community structures, dynamics, and functions at contaminated sites. These techniques have not only aided us in understanding the lifestyles of common organohalide respirers, for example Dehalococcoides, Dehalobacter, and Desulfitobacterium, but also provided insights into novel and yet uncultured microorganisms found in organohalide respiring consortia. In this paper, we look at how ecogenomic studies have aided us to understand the microbial structures and functions in response to environmental stimuli such as the presence of chlorinated pollutants. PMID:23060869

  16. Microbial diversity and their roles in the vinegar fermentation process.

    PubMed

    Li, Sha; Li, Pan; Feng, Feng; Luo, Li-Xin

    2015-06-01

    Vinegar is one of the oldest acetic acid-diluted solution products in the world. It is produced from any fermentable sugary substrate by various fermentation methods. The final vinegar products possess unique functions, which are endowed with many kinds of compounds formed in the fermentation process. The quality of vinegar is determined by many factors, especially by the raw materials and microbial diversity involved in vinegar fermentation. Given that metabolic products from the fermenting strains are directly related to the quality of the final products of vinegar, the microbial diversity and features of the dominant strains involved in different fermentation stages should be analyzed to improve the strains and stabilize fermentation. Moreover, although numerous microbiological studies have been conducted to examine the process of vinegar fermentation, knowledge about microbial diversity and their roles involved in fermentation is still fragmentary and not systematic enough. Therefore, in this review, the dominant microorganism species involved in the stages of alcoholic fermentation and acetic acid fermentation of dissimilar vinegars were summarized. We also summarized various physicochemical properties and crucial compounds in disparate types of vinegar. Furthermore, the merits and drawbacks of vital fermentation methods were generalized. Finally, we described in detail the relationships among microbial diversity, raw materials, fermentation methods, physicochemical properties, compounds, functionality, and final quality of vinegar. The integration of this information can provide us a detailed map about the microbial diversity and function involved in vinegar fermentation.

  17. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2007-01-01

    Seawater and natural brines accounted for about 52 percent of U.S. magnesium compounds production in 2006. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties from well brines in Michigan. Caustic-calcined magnesia was recovered from sea-water by Premier Chemicals in Florida; from well brines in Michigan by Martin Marietta and Rohm and Haas; and from magnesite in Nevada by Premier Chemicals. Intrepid Potash-Wendover and Great Salt Lake Minerals recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from brucite by Applied Chemical Magnesias in Texas, from seawater by SPI Pharma in Delaware and Premier Chemicals in Florida, and by Martin Marietta and Rohm and Haas from their operations mentioned above. About 59 percent of the magnesium compounds consumed in the United States was used for refractories that are used mainly to line steelmaking furnaces. The remaining 41 percent was consumed in agricultural, chemical, construction, environmental and industrial applications.

  18. Intermetallic Compounds

    NASA Astrophysics Data System (ADS)

    Takagiwa, Y.; Matsuura, Y.; Kimura, K.

    2014-06-01

    We have focused on the binary narrow-bandgap intermetallic compounds FeGa3 and RuGa3 as thermoelectric materials. Their crystal structure is FeGa3-type (tetragonal, P42/ mnm) with 16 atoms per unit cell. Despite their simple crystal structure, their room temperature thermal conductivity is in the range 4-5-W-m-1-K-1. Both compounds have narrow-bandgaps of approximately 0.3-eV near the Fermi level. Because their Seebeck coefficients are quite large negative values in the range 350-<-| S 373K|-<-550- μV-K-1 for undoped samples, it should be possible to obtain highly efficient thermoelectric materials both by adjusting the carrier concentration and by reducing the thermal conductivity. Here, we report the effects of doping on the thermoelectric properties of FeGa3 and RuGa3 as n and p-type materials. The dimensionless figure of merit, ZT, was significantly improved by substitution of Sn for Ga in FeGa3 (electron-doping) and by substitution of Zn for Ga in RuGa3 (hole-doping), mainly as a result of optimization of the electronic part, S 2 σ.

  19. Biodiversity in production of antibiotics and other bioactive compounds.

    PubMed

    Mahajan, Girish; Balachandran, Lakshmi

    2015-01-01

    Microbes continue to play a highly considerable role in the drug discovery and development process. Nevertheless, the number of new chemical entities (NCEs) of microbial origin that has been approved by the Food and Drug Administration (FDA) has been reduced in the past decade. This scarcity can be partly attributed to the redundancy in the discovered molecules from microbial isolates, which are isolated from common terrestrial ecological units. However, this situation can be partly overcome by exploring rarely exploited ecological niches as the source of microbes, which reduces the chances of isolating compounds similar to existing ones. The use of modern and advanced isolation techniques, modification of the existing fermentation methods, genetic modifications to induce expression of silent genes, analytical tools for the detection and identification of new chemical entities, use of polymers in fermentation to enhance yield of fermented compounds, and so on, have all aided in enhancing the frequency of acquiring novel compounds. These compounds are representative of numerous classes of diverse compounds. Thus, compounds of microbial origin and their analogues undergoing clinical trials continue to demonstrate the importance of compounds from microbial sources in modern drug discovery.

  20. Hydrolytic microbial communities in terrestrial ecosystems

    NASA Astrophysics Data System (ADS)

    Manucharova, Natalia; Chernov, Timofey; Kolcova, Ekaterina; Zelezova, Alena; Lukacheva, Euhenia; Zenova, Galina

    2014-05-01

    Hydrolytic microbial communities in terrestrial ecosystems Manucharova N.A., Chernov T.I., Kolcova E.M., Zelezova A.D., Lukacheva E.G. Lomonosov Moscow State University, Russia Vertical differentiation of terrestrial biogeocenoses is conditioned by the formation of vertical tiers that differ considerably in the composition and structure of microbial communities. All the three tiers, phylloplane, litter and soil, are united by a single flow of organic matter, and are spatially separated successional stages of decomposition of organic substances. Decomposition of organic matter is mainly due to the activity of microorganisms producing enzymes - hydrolase and lyase - which destroy complex organic compounds. Application of molecular biological techniques (FISH) in environmental studies provides a more complete information concerning the taxonomic diversity and potential hydrolytic activity of microbial complexes of terrestrial ecosystems that exist in a wide range of environmental factors (moisture, temperature, redox potential, organic matter). The combination of two molecular biological techniques (FISH and DGGE-analysis of fragments of gene 16S rRNA total amplificate) enables an informative assessment of the differences in the structure of dominant and minor components of hydrolytic complexes formed in different tiers of terrestrial ecosystems. The functional activity of hydrolytic microbial complexes of terrestrial ecosystems is determined by the activity of dominant and minor components, which also have a high gross enzymatic activity. Degradation of biopolymers in the phylloplane is mainly due to the representatives of the Proteobacteria phylogenetic group (classes alpha and beta). In mineral soil horizons, the role of hydrolytic representatives of Firmicutes and Actinobacteria increases. Among the key environmental parameters that determine the functional activity of the hydrolytic (chitinolytic) complex of soil layer (moisture, nutrient supply, successional

  1. Impact of a microbial-mineral biopreparation on microbial community and deodorization of manures.

    PubMed

    Matusiak, Katarzyna; Borowski, Sebastian; Opaliński, Sebastian; Bakuła, Tadeusz; Kołacz, Roman; Gutarowska, Beata

    2015-01-01

    The aim of this study was to determine the number of bacteria in poultry, cattle and swine manure in order to perform hygienization and deodorization using a microbial-mineral biopreparation. The highest number of bacteria was recorded in laying hens manure (5.1×10(10) cfu/g). It was noted that bacteria: coliforms, E. coli, Clostridium, Enterococcus number was reduced (1-2 log) after the biopreparation application. The investigated odorous compound concentrations were reduced with 34-78% efficiency, depending on the type of manure and odorant. All odorous compounds were efficiently reduced only in the case of laying hen manure.

  2. Deep subsurface microbial processes

    USGS Publications Warehouse

    Lovley, D.R.; Chapelle, F.H.

    1995-01-01

    Information on the microbiology of the deep subsurface is necessary in order to understand the factors controlling the rate and extent of the microbially catalyzed redox reactions that influence the geophysical properties of these environments. Furthermore, there is an increasing threat that deep aquifers, an important drinking water resource, may be contaminated by man's activities, and there is a need to predict the extent to which microbial activity may remediate such contamination. Metabolically active microorganisms can be recovered from a diversity of deep subsurface environments. The available evidence suggests that these microorganisms are responsible for catalyzing the oxidation of organic matter coupled to a variety of electron acceptors just as microorganisms do in surface sediments, but at much slower rates. The technical difficulties in aseptically sampling deep subsurface sediments and the fact that microbial processes in laboratory incubations of deep subsurface material often do not mimic in situ processes frequently necessitate that microbial activity in the deep subsurface be inferred through nonmicrobiological analyses of ground water. These approaches include measurements of dissolved H2, which can predict the predominant microbially catalyzed redox reactions in aquifers, as well as geochemical and groundwater flow modeling, which can be used to estimate the rates of microbial processes. Microorganisms recovered from the deep subsurface have the potential to affect the fate of toxic organics and inorganic contaminants in groundwater. Microbial activity also greatly influences 1 the chemistry of many pristine groundwaters and contributes to such phenomena as porosity development in carbonate aquifers, accumulation of undesirably high concentrations of dissolved iron, and production of methane and hydrogen sulfide. Although the last decade has seen a dramatic increase in interest in deep subsurface microbiology, in comparison with the study of

  3. Spotsizer: High-throughput quantitative analysis of microbial growth

    PubMed Central

    Jeffares, Daniel C.; Arzhaeva, Yulia; Bähler, Jürg

    2017-01-01

    Microbial colony growth can serve as a useful readout in assays for studying complex genetic interactions or the effects of chemical compounds. Although computational tools for acquiring quantitative measurements of microbial colonies have been developed, their utility can be compromised by inflexible input image requirements, non-trivial installation procedures, or complicated operation. Here, we present the Spotsizer software tool for automated colony size measurements in images of robotically arrayed microbial colonies. Spotsizer features a convenient graphical user interface (GUI), has both single-image and batch-processing capabilities, and works with multiple input image formats and different colony grid types. We demonstrate how Spotsizer can be used for high-throughput quantitative analysis of fission yeast growth. The user-friendly Spotsizer tool provides rapid, accurate, and robust quantitative analyses of microbial growth in a high-throughput format. Spotsizer is freely available at https://data.csiro.au/dap/landingpage?pid=csiro:15330 under a proprietary CSIRO license. PMID:27712582

  4. Spotsizer: High-throughput quantitative analysis of microbial growth.

    PubMed

    Bischof, Leanne; Převorovský, Martin; Rallis, Charalampos; Jeffares, Daniel C; Arzhaeva, Yulia; Bähler, Jürg

    2016-10-01

    Microbial colony growth can serve as a useful readout in assays for studying complex genetic interactions or the effects of chemical compounds. Although computational tools for acquiring quantitative measurements of microbial colonies have been developed, their utility can be compromised by inflexible input image requirements, non-trivial installation procedures, or complicated operation. Here, we present the Spotsizer software tool for automated colony size measurements in images of robotically arrayed microbial colonies. Spotsizer features a convenient graphical user interface (GUI), has both single-image and batch-processing capabilities, and works with multiple input image formats and different colony grid types. We demonstrate how Spotsizer can be used for high-throughput quantitative analysis of fission yeast growth. The user-friendly Spotsizer tool provides rapid, accurate, and robust quantitative analyses of microbial growth in a high-throughput format. Spotsizer is freely available at https://data.csiro.au/dap/landingpage?pid=csiro:15330 under a proprietary CSIRO license.

  5. Perspective for Aquaponic Systems: "Omic" Technologies for Microbial Community Analysis.

    PubMed

    Munguia-Fragozo, Perla; Alatorre-Jacome, Oscar; Rico-Garcia, Enrique; Torres-Pacheco, Irineo; Cruz-Hernandez, Andres; Ocampo-Velazquez, Rosalia V; Garcia-Trejo, Juan F; Guevara-Gonzalez, Ramon G

    2015-01-01

    Aquaponics is the combined production of aquaculture and hydroponics, connected by a water recirculation system. In this productive system, the microbial community is responsible for carrying out the nutrient dynamics between the components. The nutrimental transformations mainly consist in the transformation of chemical species from toxic compounds into available nutrients. In this particular field, the microbial research, the "Omic" technologies will allow a broader scope of studies about a current microbial profile inside aquaponics community, even in those species that currently are unculturable. This approach can also be useful to understand complex interactions of living components in the system. Until now, the analog studies were made to set up the microbial characterization on recirculation aquaculture systems (RAS). However, microbial community composition of aquaponics is still unknown. "Omic" technologies like metagenomic can help to reveal taxonomic diversity. The perspectives are also to begin the first attempts to sketch the functional diversity inside aquaponic systems and its ecological relationships. The knowledge of the emergent properties inside the microbial community, as well as the understanding of the biosynthesis pathways, can derive in future biotechnological applications. Thus, the aim of this review is to show potential applications of current "Omic" tools to characterize the microbial community in aquaponic systems.

  6. Lipid Biomarkers for a Hypersaline Microbial Mat Community

    NASA Technical Reports Server (NTRS)

    Jahnke, Linda L.; Embaye, Tsege; Turk, Kendra A.

    2003-01-01

    The use of lipid biomarkers and their carbon isotopic compositions are valuable tools for establishing links to ancient microbial ecosystems. As witnessed by the stromatolite record, benthic microbial mats grew in shallow water lagoonal environments where microorganisms had virtually no competition apart from the harsh conditions of hypersalinity, desiccation and intense light. Today, the modern counterparts of these microbial ecosystems find appropriate niches in only a few places where extremes eliminate eukaryotic grazers. Answers to many outstanding questions about the evolution of microorganisms and their environments on early Earth are best answered through study of these extant analogs. Lipids associated with various groups of bacteria can be valuable biomarkers for identification of specific groups of microorganisms both in ancient organic-rich sedimentary rocks (geolipids) and contemporary microbial communities (membrane lipids). Use of compound specific isotope analysis adds additional refinement to the identification of biomarker source, so that it is possible to take advantage of the 3C-depletions associated with various functional groups of organisms (i.e. autotrophs, heterotrophs, methanotrophs, methanogens) responsible for the cycling of carbon within a microbial community. Our recent work has focused on a set of hypersaline evaporation ponds at Guerrero Negro, Baja California Sur, Mexico which support the abundant growth of Microcoleus-dominated microbial mats. Specific biomarkers for diatoms, cyanobacteria, archaea, green nonsulfur (GNS), sulfate reducing, and methanotrophic bacteria have been identified. Analyses of the ester-bound fatty acids indicate a highly diverse microbial community, dominated by photosynthetic organisms at the surface.

  7. Microbial production strategies and applications of lycopene and other terpenoids.

    PubMed

    Ma, Tian; Deng, Zixin; Liu, Tiangang

    2016-01-01

    Terpenoids are a large class of compounds that have far-reaching applications and economic value, particularly those most commonly found in plants; however, the extraction and synthesis of these compounds is often expensive and technically challenging. Recent advances in microbial metabolic engineering comprise a breakthrough that may enable the efficient, cost-effective production of these limited natural resources. Via the engineering of safe, industrial microorganisms that encode product-specific enzymes, and even entire metabolic pathways of interest, microbial-derived semisynthetic terpenoids may soon replace plant-derived terpenoids as the primary source of these valuable compounds. Indeed, the recent metabolic engineering of an Escherichia coli strain that produces the precursor to lycopene, a commercially and medically important compound, with higher yields than those in tomato plants serves as a successful example. Here, we review the recent developments in the metabolic engineering of microbes for the production of certain terpenoid compounds, particularly lycopene, which has been increasingly used in pharmaceuticals, nutritional supplements, and cosmetics. Furthermore, we summarize the metabolic engineering strategies used to achieve successful microbial production of some similar compounds. Based on this overview, there is a reason to believe that metabolic engineering comprises an optimal approach for increasing the production of lycopene and other terpenoids.

  8. Magnesium compounds

    USGS Publications Warehouse

    Kramer, D.A.

    2012-01-01

    Seawater and natural brines accounted for about 57 percent of magnesium compounds produced in the United States in 2011. Dead-burned magnesia was produced by Martin Marietta Magnesia Specialties LLC from well brines in Michigan. Caustic-calcined magnesia was recovered from seawater by Premier Magnesia LLC in Florida, from well brines in Michigan by Martin Marietta and from magnesite in Nevada by Premier Magnesia. Intrepid Potash Wendover LLC and Great Salt Lake Minerals Corp. recovered magnesium chloride brines from the Great Salt Lake in Utah. Magnesium hydroxide was produced from seawater by SPI Pharma Inc. in Delaware and Premier Magnesia in Florida, and by Martin Marietta from its brine operation in Michigan.

  9. Bismaleimide compounds

    DOEpatents

    Adams, Johnnie E.; Jamieson, Donald R.

    1986-01-14

    Bismaleimides of the formula ##STR1## wherein R.sub.1 and R.sub.2 each independently is H, C.sub.1-4 -alkyl, C.sub.1-4 -alkoxy, C1 or Br, or R.sub.1 and R.sub.2 together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R.sub.1 and R.sub.2 are not t-butyl or t-butoxy; X is O, S or Se; n is 1-3; and the alkylene bridging group, optionally, is substituted by 1-3 methyl groups or by fluorine, form polybismaleimide resins which have valuable physical properties. Uniquely, these compounds permit extended cure times, i.e., they remain fluid for a time sufficient to permit the formation of a homogeneous melt prior to curing.

  10. Bismaleimide compounds

    DOEpatents

    Adams, J.E.; Jamieson, D.R.

    1986-01-14

    Bismaleimides of the formula shown in the diagram wherein R[sub 1] and R[sub 2] each independently is H, C[sub 1-4]-alkyl, C[sub 1-4]-alkoxy, Cl or Br, or R[sub 1] and R[sub 2] together form a fused 6-membered hydrocarbon aromatic ring, with the proviso that R[sub 1] and R[sub 2] are not t-butyl or t-butoxy; X is O, S or Se; n is 1--3; and the alkylene bridging group, optionally, is substituted by 1--3 methyl groups or by fluorine, form polybismaleimide resins which have valuable physical properties. Uniquely, these compounds permit extended cure times, i.e., they remain fluid for a time sufficient to permit the formation of a homogeneous melt prior to curing.

  11. Bioactive natural products from novel microbial sources.

    PubMed

    Challinor, Victoria L; Bode, Helge B

    2015-09-01

    Despite the importance of microbial natural products for human health, only a few bacterial genera have been mined for the new natural products needed to overcome the urgent threat of antibiotic resistance. This is surprising, given that genome sequencing projects have revealed that the capability to produce natural products is not a rare feature among bacteria. Even the bacteria occurring in the human microbiome produce potent antibiotics, and thus potentially are an untapped resource for novel compounds, potentially with new activities. This review highlights examples of bacteria that should be considered new sources of natural products, including anaerobes, pathogens, and symbionts of humans, insects, and nematodes. Exploitation of these producer strains, combined with advances in modern natural product research methodology, has the potential to open the way for a new golden age of microbial therapeutics.

  12. Microbial fuel cell with improved anode

    DOEpatents

    Borole, Abhijeet P.

    2010-04-13

    The present invention relates to a method for preparing a microbial fuel cell, wherein the method includes: (i) inoculating an anodic liquid medium in contact with an anode of the microbial fuel cell with one or more types of microorganisms capable of functioning by an exoelectrogenic mechanism; (ii) establishing a biofilm of the microorganisms on and/or within the anode along with a substantial absence of planktonic forms of the microorganisms by substantial removal of the planktonic microorganisms during forced flow and recirculation conditions of the anodic liquid medium; and (iii) subjecting the microorganisms of the biofilm to a growth stage by incorporating one or more carbon-containing nutritive compounds in the anodic liquid medium during biofilm formation or after biofilm formation on the anode has been established.

  13. Microbial production of value-added nutraceuticals.

    PubMed

    Wang, Jian; Guleria, Sanjay; Koffas, Mattheos A G; Yan, Yajun

    2016-02-01

    Nutraceuticals are important natural bioactive compounds that confer health-promoting and medical benefits to humans. Globally growing demands for value-added nutraceuticals for prevention and treatment of human diseases have rendered nutraceuticals a multi-billion dollar market. However, supply limitations and extraction difficulties from natural sources such as plants, animals or fungi, restrict the large-scale use of nutraceuticals. Metabolic engineering via microbial production platforms has been advanced as an eco-friendly alternative approach for production of value-added nutraceuticals from simple carbon sources. Microbial platforms like the most widely used Escherichia coli and Saccharomyces cerevisiae have been engineered as versatile cell factories for production of diverse and complex value-added chemicals such as phytochemicals, prebiotics, polysaccaharides and poly amino acids. This review highlights the recent progresses in biological production of value-added nutraceuticals via metabolic engineering approaches.

  14. Microbial Ecology of and Antimicrobial Resistance in Stored Swine Manure

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial compounds such as tylosin have been commonly used as feed additives for domestic animals to reduce infection and promote growth. Recent reports have suggested such feeding practices may result in increased microbial resistance to antibiotics, which can have an impact on human health. ...

  15. Granular Microbial Habitats Built from Iron Sulfides: Alternative Microbial Lifestyles?

    NASA Astrophysics Data System (ADS)

    Schieber, J.

    2005-03-01

    Concentrically zoned pyrite grains grew as granular microbial colonies. They stayed in the surface layer during long history of reworking and accretion and consist of marcasite and pyrite cortices with sulfide mineralized microbial remains.

  16. The Microbial Olympics

    PubMed Central

    Youle, Merry; Rohwer, Forest; Stacy, Apollo; Whiteley, Marvin; Steel, Bradley C.; Delalez, Nicolas J.; Nord, Ashley L.; Berry, Richard M.; Armitage, Judith P.; Kamoun, Sophien; Hogenhout, Saskia; Diggle, Stephen P.; Gurney, James; Pollitt, Eric J. G.; Boetius, Antje; Cary, S. Craig

    2014-01-01

    Every four years, the Olympic Games plays host to competitors who have built on their natural talent by training for many years to become the best in their chosen discipline. Similar spirit and endeavour can be found throughout the microbial world, in which every day is a competition to survive and thrive. Microorganisms are trained through evolution to become the fittest and the best adapted to a particular environmental niche or lifestyle, and to innovate when the ‘rules of the game’ are changed by alterations to their natural habitats. In this Essay, we honour the best competitors in the microbial world by inviting them to take part in the inaugural Microbial Olympics. PMID:22796885

  17. Retro-Biosynthesis for the Microbial Production of Organic Compounds

    DTIC Science & Technology

    2008-05-31

    product of this natural biosynthetic route is L- ascorbic acid (vitamin C). Thus, we chose to propose rationally-designed pathways for the...is the oxidation of glucose to form glucodialdose. A galactose oxidase is known to catalyze the desired reaction using galactose as a substrate...higher activities than what has previously been reported. We received the first library, a control library, to screen for a new glucose oxidase

  18. Microbial Load Monitor

    NASA Technical Reports Server (NTRS)

    Gibson, S. F.; Royer, E. R.

    1979-01-01

    The Microbial Load Monitor (MLM) is an automated and computerized system for detection and identification of microorganisms. Additionally, the system is designed to enumerate and provide antimicrobic susceptibility profiles for medically significant bacteria. The system is designed to accomplish these tasks in a time of 13 hours or less versus the traditional time of 24 hours for negatives and 72 hours or more for positives usually required for standard microbiological analysis. The MLM concept differs from other methods of microbial detection in that the system is designed to accept raw untreated clinical samples and to selectively identify each group or species that may be present in a polymicrobic sample.

  19. Microbial Control News - November 2011

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is the first of a column in the Society for Invertebrate Pathology Newsletter. Entitled "Microbial Control News" this article summarizes regulatory actions in the U.S. and Canada regarding microbial insect pest control agents....

  20. Biodegradation of halogenated organic compounds.

    PubMed Central

    Chaudhry, G R; Chapalamadugu, S

    1991-01-01

    In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant

  1. Segregation of the Anodic Microbial Communities in a Microbial Fuel Cell Cascade

    PubMed Central

    Hodgson, Douglas M.; Smith, Ann; Dahale, Sonal; Stratford, James P.; Li, Jia V.; Grüning, André; Bushell, Michael E.; Marchesi, Julian R.; Avignone Rossa, C.

    2016-01-01

    Metabolic interactions within microbial communities are essential for the efficient degradation of complex organic compounds, and underpin natural phenomena driven by microorganisms, such as the recycling of carbon-, nitrogen-, and sulfur-containing molecules. These metabolic interactions ultimately determine the function, activity and stability of the community, and therefore their understanding would be essential to steer processes where microbial communities are involved. This is exploited in the design of microbial fuel cells (MFCs), bioelectrochemical devices that convert the chemical energy present in substrates into electrical energy through the metabolic activity of microorganisms, either single species or communities. In this work, we analyzed the evolution of the microbial community structure in a cascade of MFCs inoculated with an anaerobic microbial community and continuously fed with a complex medium. The analysis of the composition of the anodic communities revealed the establishment of different communities in the anodes of the hydraulically connected MFCs, with a decrease in the abundance of fermentative taxa and a concurrent increase in respiratory taxa along the cascade. The analysis of the metabolites in the anodic suspension showed a metabolic shift between the first and last MFC, confirming the segregation of the anodic communities. Those results suggest a metabolic interaction mechanism between the predominant fermentative bacteria at the first stages of the cascade and the anaerobic respiratory electrogenic population in the latter stages, which is reflected in the observed increase in power output. We show that our experimental system represents an ideal platform for optimization of processes where the degradation of complex substrates is involved, as well as a potential tool for the study of metabolic interactions in complex microbial communities. PMID:27242723

  2. Segregation of the Anodic Microbial Communities in a Microbial Fuel Cell Cascade.

    PubMed

    Hodgson, Douglas M; Smith, Ann; Dahale, Sonal; Stratford, James P; Li, Jia V; Grüning, André; Bushell, Michael E; Marchesi, Julian R; Avignone Rossa, C

    2016-01-01

    Metabolic interactions within microbial communities are essential for the efficient degradation of complex organic compounds, and underpin natural phenomena driven by microorganisms, such as the recycling of carbon-, nitrogen-, and sulfur-containing molecules. These metabolic interactions ultimately determine the function, activity and stability of the community, and therefore their understanding would be essential to steer processes where microbial communities are involved. This is exploited in the design of microbial fuel cells (MFCs), bioelectrochemical devices that convert the chemical energy present in substrates into electrical energy through the metabolic activity of microorganisms, either single species or communities. In this work, we analyzed the evolution of the microbial community structure in a cascade of MFCs inoculated with an anaerobic microbial community and continuously fed with a complex medium. The analysis of the composition of the anodic communities revealed the establishment of different communities in the anodes of the hydraulically connected MFCs, with a decrease in the abundance of fermentative taxa and a concurrent increase in respiratory taxa along the cascade. The analysis of the metabolites in the anodic suspension showed a metabolic shift between the first and last MFC, confirming the segregation of the anodic communities. Those results suggest a metabolic interaction mechanism between the predominant fermentative bacteria at the first stages of the cascade and the anaerobic respiratory electrogenic population in the latter stages, which is reflected in the observed increase in power output. We show that our experimental system represents an ideal platform for optimization of processes where the degradation of complex substrates is involved, as well as a potential tool for the study of metabolic interactions in complex microbial communities.

  3. Recent Advances in Microbial Electrocatalysis

    DTIC Science & Technology

    2014-01-01

    Microbial electrocatalysis is a relatively new field of research in which the intrinsic metabolic capacities of various microbes are coupled with...inorganic electrodes to carryout interesting chemical conversions. Given the great diversity in microbial metabolic pathways, a wide variety of processes...past decade. A relatively new development is electrosynthesis, the electrically driven fixation of CO2 into various chemicals. Moreover, microbial

  4. Streptomyces metabolites in divergent microbial interactions.

    PubMed

    Takano, Hideaki; Nishiyama, Tatsuya; Amano, Sho-ichi; Beppu, Teruhiko; Kobayashi, Michihiko; Ueda, Kenji

    2016-03-01

    Streptomyces and related bacteria produce a wide variety of secondary metabolites. Of these, many compounds have industrial applications, but the question of why this group of microorganism produces such various kinds of biologically active substances has not yet been clearly answered. Here, we overview the results from our studies on the novel function and role of Streptomyces metabolites. The diverged action of negative and positive influences onto the physiology of various microorganisms infers the occurrence of complex microbial interactions due to the effect of small molecules produced by Streptomyces. The interactions may serve as a basis for the constitution of biological community.

  5. Characterization of microbial siderophores by mass spectrometry.

    PubMed

    Pluháček, Tomáš; Lemr, Karel; Ghosh, Dipankar; Milde, David; Novák, Jiří; Havlíček, Vladimír

    2016-01-01

    Siderophores play important roles in microbial iron piracy, and are applied as infectious disease biomarkers and novel pharmaceutical drugs. Inductively coupled plasma and molecular mass spectrometry (ICP-MS) combined with high resolution separations allow characterization of siderophores in complex samples taking advantages of mass defect data filtering, tandem mass spectrometry, and iron-containing compound quantitation. The enrichment approaches used in siderophore analysis and current ICP-MS technologies are reviewed. The recent tools for fast dereplication of secondary metabolites and their databases are reported. This review on siderophores is concluded with their recent medical, biochemical, geochemical, and agricultural applications in mass spectrometry context.

  6. Pretreatment of microbial sludges

    DOEpatents

    Rivard, C.J.; Nagle, N.J.

    1995-01-10

    Methods are described for pretreating microbial sludges to break cells and disrupt organic matter. One method involves the use of sonication, and another method involves the use of shear forces. The pretreatment of sludge enhances bioconversion of the organic fraction. This allows for efficient dewatering of the sludge and reduces the cost for final disposal of the waste.

  7. Pretreatment of microbial sludges

    DOEpatents

    Rivard, Christopher J.; Nagle, Nicholas J.

    1995-01-01

    Methods are described for pretreating microbial sludges to break cells and disrupt organic matter. One method involves the use of sonication, and another method involves the use of shear forces. The pretreatment of sludge enhances bioconversion of the organic fraction. This allows for efficient dewatering of the sludge and reduces the cost for final disposal of the waste.

  8. Microbial Weathering of Olivine

    NASA Technical Reports Server (NTRS)

    McKay, D. S.; Longazo, T. G.; Wentworth, S. J.; Southam, G.

    2002-01-01

    Controlled microbial weathering of olivine experiments displays a unique style of nanoetching caused by biofilm attachment to mineral surfaces. We are investigating whether the morphology of biotic nanoetching can be used as a biosignature. Additional information is contained in the original extended abstract.

  9. Indirect microbial detection

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.

    1980-01-01

    Indirect method for detection of microbial growth utilizes flow of charged particles across barrier that physically separated growing cells from electrodes and measures resulting difference in potential between two platinum electrodes. Technique allows simplified noncontact monitoring of all growth in highly infectious cultures or in critical biochemical studies.

  10. Automated Microbial Genome Annotation

    SciTech Connect

    Land, Miriam

    2009-05-29

    Miriam Land of the DOE Joint Genome Institute at Oak Ridge National Laboratory gives a talk on the current state and future challenges of moving toward automated microbial genome annotation at the "Sequencing, Finishing, Analysis in the Future" meeting in Santa Fe, NM

  11. SEAGRASS RHIZOSPHERE MICROBIAL COMMUNITIES

    EPA Science Inventory

    Devereux, Richard. 2005. Seagrass Rhizosphere Microbial Communities. In: Interactions Between Macro- and Microorganisms in Marine Sediments. E. Kristense, J.E. Kostka and R.H. Haese, Editors. American Geophysical Union, Washington, DC. p199-216. (ERL,GB 1213).

    Seagrasses ...

  12. A Microbial Murder Mystery.

    ERIC Educational Resources Information Center

    Mitchell, Melissa A.; Mitchell, James K.

    2002-01-01

    Proposes a microbial mystery activity to test students' knowledge of human anatomy and their ability to identify microbes. Provides an opportunity for students to develop logical deductive reasoning. Includes national science education standards related to this activity, activity sheets with whole procedures, and Internet resources. (KHR)

  13. Indirect microbial detection

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R. (Inventor)

    1981-01-01

    The growth of microorganisms in a sample is detected and monitored by culturing microorganisms in a growth medium and detecting a change in potential between two electrodes, separated from the microbial growth by a barrier which is permeable to charged paticles but microorganism impermeable.

  14. 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.

  15. Microbial Energy Conversion

    SciTech Connect

    Buckley, Merry; Wall, Judy D.

    2006-10-01

    The American Academy of Microbiology convened a colloquium March 10-12, 2006, in San Francisco, California, to discuss the production of energy fuels by microbial conversions. The status of research into various microbial energy technologies, the advantages and disadvantages of each of these approaches, research needs in the field, and education and training issues were examined, with the goal of identifying routes for producing biofuels that would both decrease the need for fossil fuels and reduce greenhouse gas emissions. Currently, the choices for providing energy are limited. Policy makers and the research community must begin to pursue a broader array of potential energy technologies. A diverse energy portfolio that includes an assortment of microbial energy choices will allow communities and consumers to select the best energy solution for their own particular needs. Funding agencies and governments alike need to prepare for future energy needs by investing both in the microbial energy technologies that work today and in the untested technologies that will serve the world’s needs tomorrow. More mature bioprocesses, such as ethanol production from starchy materials and methane from waste digestors, will find applications in the short term. However, innovative techniques for liquid fuel or biohydrogen production are among the longer term possibilities that should also be vigorously explored, starting now. Microorganisms can help meet human energy needs in any of a number of ways. In their most obvious role in energy conversion, microorganisms can generate fuels, including ethanol, hydrogen, methane, lipids, and butanol, which can be burned to produce energy. Alternatively, bacteria can be put to use in microbial fuel cells, where they carry out the direct conversion of biomass into electricity. Microorganisms may also be used some day to make oil and natural gas technologies more efficient by sequestering carbon or by assisting in the recovery of oil and

  16. Microbial load monitor

    NASA Technical Reports Server (NTRS)

    Caplin, R. S.; Royer, E. R.

    1977-01-01

    Design analysis of a microbial load monitor system flight engineering model was presented. Checkout of the card taper and media pump system was fabricated as well as the final two incubating reading heads, the sample receiving and card loading device assembly, related sterility testing, and software. Progress in these areas was summarized.

  17. Extremely Randomized Machine Learning Methods for Compound Activity Prediction.

    PubMed

    Czarnecki, Wojciech M; Podlewska, Sabina; Bojarski, Andrzej J

    2015-11-09

    Speed, a relatively low requirement for computational resources and high effectiveness of the evaluation of the bioactivity of compounds have caused a rapid growth of interest in the application of machine learning methods to virtual screening tasks. However, due to the growth of the amount of data also in cheminformatics and related fields, the aim of research has shifted not only towards the development of algorithms of high predictive power but also towards the simplification of previously existing methods to obtain results more quickly. In the study, we tested two approaches belonging to the group of so-called 'extremely randomized methods'-Extreme Entropy Machine and Extremely Randomized Trees-for their ability to properly identify compounds that have activity towards particular protein targets. These methods were compared with their 'non-extreme' competitors, i.e., Support Vector Machine and Random Forest. The extreme approaches were not only found out to improve the efficiency of the classification of bioactive compounds, but they were also proved to be less computationally complex, requiring fewer steps to perform an optimization procedure.

  18. Palygorskite changes heavy metal bioavailability and microbial functional diversity in sewage sludge composting.

    PubMed

    Liu, Siying; Liu, Jia; Zhao, Juanjuan; Xia, Dongsheng; Pan, Fei; Liu, Ci; Kyzas, George Z; Fu, Jie

    2015-01-01

    To investigate the effects of palygorskite on chemical forms of heavy metal and microbial functional diversity in the sewage sludge composting, a compost matrix of sewage sludge, wheat straw and varying contents of palygorskite were inoculated with the compound microbial preparation. The chemical speciation analysis by a Community Bureau of Reference-sequential extraction indicated the contribution of palygorskite to reduce the bioavailability of a model metal, Cu, during the composting process. The Biolog EcoPlate(TM) test revealed that the microbial community showed better capability of utilizing complex macro-molecules (such as miscellaneous and polymers) in the presence of palygorskite. Increasing the palygorskite contents from 1% to 5%, the microbial activity showed an increasing tendency. However, continuously increasing the palygorskite resulted in a decline of the microbial metabolism. Therefore, appropriate content of palygorskite is an ideal additive for composting, not only enhancing the microbial activity, but also reducing the metal toxicity.

  19. Chemistry of green encapsulating molding compounds at interfaces with other materials in electronic devices

    NASA Astrophysics Data System (ADS)

    Scandurra, A.; Zafarana, R.; Tenya, Y.; Pignataro, S.

    2004-07-01

    The interface chemistry between encapsulating epoxy phenolic molding compound (EMC) containing phosphorous based organic flame retardant (the so called "green materials") and copper oxide-hydroxide and aluminum oxide-hydroxide surfaces have been studied in comparison with "conventional" EMC containing bromine and antimony as flame retardant. These green materials are designed to reduce the presence of toxic elements in the electronic packages and, consequently, in the environment. For the study were used a Scanning Acoustic Microscopy for delamination measurements, a dynamometer for the pull strength measurements and an ESCA spectrometer for chemical analysis of the interface. The general behavior of the green compound in terms of delamination, adhesion, and corrosion is found better or at least comparable than that of the conventional EMC.

  20. Processing of disyllabic compound words in Chinese aphasia: evidence for the processing limitations account.

    PubMed

    Lee, Chia-Lin; Hung, Daisy L; Tse, John K-P; Lee, Chia-Ying; Tsai, Jie-Li; Tzeng, Ovid J-L

    2005-02-01

    The current study addresses the debate between so-called 'structural' and 'processing limitation' accounts of aphasia, i.e., whether language impairments reflect the 'loss' of linguistic knowledge or its representations, or instead reflect a limitation in processing resources. Confrontation-naming task and category-judgment tasks were used to examine and compare the performance of non-fluent and fluent aphasics on different compound types of nouns and verbs. We demonstrate that aphasic patients' performance is modulated by the canonicity of the particular compound type, a result that holds true even for the category in which patients show a 'selective category deficit.' These findings weigh against the 'loss' of linguistic representations as the underlying cause of noun-verb deficits, instead supporting a 'processing limitations' approach.

  1. Insights into the phylogeny and coding potential of microbial dark matter

    NASA Astrophysics Data System (ADS)

    Rinke, Christian; Schwientek, Patrick; Sczyrba, Alexander; Ivanova, Natalia N.; Anderson, Iain J.; Cheng, Jan-Fang; Darling, Aaron; Malfatti, Stephanie; Swan, Brandon K.; Gies, Esther A.; Dodsworth, Jeremy A.; Hedlund, Brian P.; Tsiamis, George; Sievert, Stefan M.; Liu, Wen-Tso; Eisen, Jonathan A.; Hallam, Steven J.; Kyrpides, Nikos C.; Stepanauskas, Ramunas; Rubin, Edward M.; Hugenholtz, Philip; Woyke, Tanja

    2013-07-01

    Genome sequencing enhances our understanding of the biological world by providing blueprints for the evolutionary and functional diversity that shapes the biosphere. However, microbial genomes that are currently available are of limited phylogenetic breadth, owing to our historical inability to cultivate most microorganisms in the laboratory. We apply single-cell genomics to target and sequence 201 uncultivated archaeal and bacterial cells from nine diverse habitats belonging to 29 major mostly uncharted branches of the tree of life, so-called `microbial dark matter'. With this additional genomic information, we are able to resolve many intra- and inter-phylum-level relationships and to propose two new superphyla. We uncover unexpected metabolic features that extend our understanding of biology and challenge established boundaries between the three domains of life. These include a novel amino acid use for the opal stop codon, an archaeal-type purine synthesis in Bacteria and complete sigma factors in Archaea similar to those in Bacteria. The single-cell genomes also served to phylogenetically anchor up to 20% of metagenomic reads in some habitats, facilitating organism-level interpretation of ecosystem function. This study greatly expands the genomic representation of the tree of life and provides a systematic step towards a better understanding of biological evolution on our planet.

  2. Insights into the phylogeny and coding potential of microbial dark matter

    SciTech Connect

    Rinke, Christian; Schwientek, Patrick; Sczyrba, Alexander; Ivanova, Natalia N.; Anderson, Iain J.; Cheng, Jan-Fang; Darling, Aaron; Malfatti, Stephanie; Swan, Brandon K.; Gies, Esther A.; Dodsworth, Jeremy A.; Hedlund, Brian P.; Tsiamis, George; Sievert, Stefan M.; Liu, Wen-Tso; Eisen, Jonathan A.; Hallam, Steven J.; Kyrpides, Nikos C.; Stepanauskas, Ramunas; Rubin, Edward M.; Hugenholtz, Philip; Woyke, Tanja

    2013-07-01

    Genome sequencing enhances our understanding of the biological world by providing blueprints for the evolutionary and functional diversity that shapes the biosphere. However, microbial genomes that are currently available are of limited phylogenetic breadth, owing to our historical inability to cultivate most microorganisms in the laboratory. We apply single-cell genomics to target and sequence 201 uncultivated archaeal and bacterial cells fromnine diverse habitats belonging to 29 major mostly uncharted branches of the tree of life, so-called microbial dark matter. With this additional genomic information, we are able to resolve many intra- and inter-phylum-level relationships and to propose two new superphyla. We uncover unexpected metabolic features that extend our understanding of biology and challenge established boundaries between the three domains of life. These include a novel amino acid use for the opal stop codon, an archaeal-type purine synthesis in Bacteria and complete sigma factors in Archaea similar to those in Bacteria. The single-cell genomes also served to phylogenetically anchor up to 20percent of metagenomic reads in some habitats, facilitating organism-level interpretation of ecosystem function. This study greatly expands the genomic representation of the tree of life and provides a systematic step towards a better understanding of biological evolution on our planet.

  3. High CO2 subsurface environment enriches for novel microbial lineages capable of autotrophic carbon fixation

    NASA Astrophysics Data System (ADS)

    Probst, A. J.; Jerett, J.; Castelle, C. J.; Thomas, B. C.; Sharon, I.; Brown, C. T.; Anantharaman, K.; Emerson, J. B.; Hernsdorf, A. W.; Amano, Y.; Suzuki, Y.; Tringe, S. G.; Woyke, T.; Banfield, J. F.

    2015-12-01

    Subsurface environments span the planet but remain little understood from the perspective of the capacity of the resident organisms to fix CO2. Here we investigated the autotrophic capacity of microbial communities in range of a high-CO2 subsurface environments via analysis of 250 near-complete microbial genomes (151 of them from distinct species) that represent the most abundant organisms over a subsurface depth transect. More than one third of the genomes belonged to the so-called candidate phyla radiation (CPR), which have limited metabolic capabilities. Approximately 30% of the community members are autotrophs that comprise 70% of the microbiome with metabolism likely supported by sulfur and nitrogen respiration. Of the carbon fixation pathways, the Calvin Benson Basham Cycle was most common, but the Wood-Ljungdhal pathway was present in the greatest phylogenetic diversity of organisms. Unexpectedly, one organism from a novel phylum sibling to the CPR is predicted to fix carbon by the reverse TCA cycle. The genome of the most abundant organism, an archaeon designated "Candidatus Altiarchaeum hamiconexum", was also found in subsurface samples from other continents including Europe and Asia. The archaeon was proven to be a carbon fixer using a novel reductive acetyl-CoA pathway. These results provide evidence that carbon dioxide is the major carbon source in these environments and suggest that autotrophy in the subsurface represents a substantial carbon dioxide sink affecting the global carbon cycle.

  4. Microbial community structure of two freshwater sponges using Illumina MiSeq sequencing revealed high microbial diversity.

    PubMed

    Gaikwad, Swapnil; Shouche, Yogesh S; Gade, Wasudev N

    2016-12-01

    Sponges are primitive metazoans that are known to harbour diverse and abundant microbes. All over the world attempts are being made to exploit these microbes for their biotechnological potential to produce, bioactive compounds and antimicrobial peptides. However, the majority of the studies are focussed on the marine sponges and studies on the freshwater sponges have been neglected so far. To increase our understanding of the microbial community structure of freshwater sponges, microbiota of two fresh water sponges namely, Eunapius carteri and Corvospongilla lapidosa is explored for the first time using Next Generation Sequencing (NGS) technology. Overall the microbial composition of these sponges comprises of 14 phyla and on an average, more than 2900 OTUs were obtained from C. lapidosa while E. carteri showed 980 OTUs which is higher than OTUs obtained in the marine sponges. Thus, our study showed that, fresh water sponges also posses highly diverse microbial community than previously thought and it is distinct from the marine sponge microbiota. The present study also revealed that microbial community structure of both the sponges is significantly different from each other and their respective water samples. In the present study, we have detected many bacterial lineages belonging to Firmicutes, Actinobacteria, Proteobacteria, Planctomycetes, etc. that are known to produce compounds of biotechnological importance. Overall, this study gives insight into the microbial composition of the freshwater sponges which is highly diverse and needs to be studied further to exploit their biotechnological capabilities.

  5. Applications of Microbial Cell Sensors

    NASA Astrophysics Data System (ADS)

    Shimomura-Shimizu, Mifumi; Karube, Isao

    Since the first microbial cell sensor was studied by Karube et al. in 1977, many types of microbial cell sensors have been developed as analytical tools. The microbial cell sensor utilizes microbes as a sensing element and a transducer. The characteristics of microbial cell sensors as sensing devices are a complete contrast to those of enzyme sensors or immunosensors, which are highly specific for the substrates of interest, although the specificity of the microbial cell sensor has been improved by genetic modification of the microbe used as the sensing element. Microbial cell sensors have the advantages of tolerance to measuring conditions, a long lifetime, and good cost performance, and have the disadvantage of a long response time. In this review, applications of microbial cell sensors are summarized.

  6. Possibilities for extremophilic microorganisms in microbial electrochemical systems

    PubMed Central

    Dopson, Mark; Ni, Gaofeng; Sleutels, Tom HJA

    2015-01-01

    Microbial electrochemical systems exploit the metabolism of microorganisms to generate electrical energy or a useful product. In the past couple of decades, the application of microbial electrochemical systems has increased from the use of wastewaters to produce electricity to a versatile technology that can use numerous sources for the extraction of electrons on the one hand, while on the other hand these electrons can be used to serve an ever increasing number of functions. Extremophilic microorganisms grow in environments that are hostile to most forms of life and their utilization in microbial electrochemical systems has opened new possibilities to oxidize substrates in the anode and produce novel products in the cathode. For example, extremophiles can be used to oxidize sulfur compounds in acidic pH to remediate wastewaters, generate electrical energy from marine sediment microbial fuel cells at low temperatures, desalinate wastewaters and act as biosensors of low amounts of organic carbon. In this review, we will discuss the recent advances that have been made in using microbial catalysts under extreme conditions and show possible new routes that extremophilic microorganisms open for microbial electrochemical systems. PMID:26474966

  7. Possibilities for extremophilic microorganisms in microbial electrochemical systems.

    PubMed

    Dopson, Mark; Ni, Gaofeng; Sleutels, Tom H J A

    2016-03-01

    Microbial electrochemical systems exploit the metabolism of microorganisms to generate electrical energy or a useful product. In the past couple of decades, the application of microbial electrochemical systems has increased from the use of wastewaters to produce electricity to a versatile technology that can use numerous sources for the extraction of electrons on the one hand, while on the other hand these electrons can be used to serve an ever increasing number of functions. Extremophilic microorganisms grow in environments that are hostile to most forms of life and their utilization in microbial electrochemical systems has opened new possibilities to oxidize substrates in the anode and produce novel products in the cathode. For example, extremophiles can be used to oxidize sulfur compounds in acidic pH to remediate wastewaters, generate electrical energy from marine sediment microbial fuel cells at low temperatures, desalinate wastewaters and act as biosensors of low amounts of organic carbon. In this review, we will discuss the recent advances that have been made in using microbial catalysts under extreme conditions and show possible new routes that extremophilic microorganisms open for microbial electrochemical systems.

  8. Microbial degradation of chloroethenes in groundwater systems

    USGS Publications Warehouse

    Bradley, P.M.

    2000-01-01

    The chloroethenes, tetrachloroethene (PCE) and trichloroethene (TCE) are among the most common contaminants detected in groundwater systems. As recently as 1980, the consensus was that chloroethene compounds were not significantly biodegradable in groundwater. Consequently, efforts to remediate chloroethene-contaminated groundwater were limited to largely unsuccessful pump-and-treat attempts. Subsequent investigation revealed that under reducing conditions, aquifer microorganisms can reductively dechlorinate PCE and TCE to the less chlorinated daughter products dichloroethene (DCE) and vinyl chloride (VC). Although recent laboratory studies conducted with halorespiring microorganisms suggest that complete reduction to ethene is possible, in the majority of groundwater systems reductive dechlorination apparently stops at DCE or VC. However, recent investigations conducted with aquifer and stream-bed sediments have demonstrated that microbial oxidation of these reduced daughter products can be significant under anaerobic redox conditions. The combination of reductive dechlorination of PCE and TCE under anaerobic conditions followed by anaerobic microbial oxidation of DCE and VC provides a possible microbial pathway for complete degradation of chloroethene contaminants in groundwater systems.

  9. Microbial degradation of chloroethenes in groundwater systems

    USGS Publications Warehouse

    Bradley, Paul M.

    2000-01-01

     The chloroethenes, tetrachloroethene (PCE) and trichloroethene (TCE) are among the most common contaminants detected in groundwater systems. As recently as 1980, the consensus was that chloroethene compounds were not significantly biodegradable in groundwater. Consequently, efforts to remediate chloroethene-contaminated groundwater were limited to largely unsuccessful pump-and-treat attempts. Subsequent investigation revealed that under reducing conditions, aquifer microorganisms can reductively dechlorinate PCE and TCE to the less chlorinated daughter products dichloroethene (DCE) and vinyl chloride (VC). Although recent laboratory studies conducted with halorespiring microorganisms suggest that complete reduction to ethene is possible, in the majority of groundwater systems reductive dechlorination apparently stops at DCE or VC. However, recent investigations conducted with aquifer and stream-bed sediments have demonstrated that microbial oxidation of these reduced daughter products can be significant under anaerobic redox conditions. The combination of reductive dechlorination of PCE and TCE under anaerobic conditions followed by anaerobic microbial oxidation of DCE and VC provides a possible microbial pathway for complete degradation of chloroethene contaminants in groundwater systems.

  10. CHARACTERIZING THE ABIOTIC REDUCTANTS FOR NITROAROMATIC COMPOUNDS AS A FUNCTION OF REDOX ZONATION IN ANOXIC SEDIMENTS

    EPA Science Inventory

    Reductive transformation is the dominant reaction pathway for the degradation of nitroaromatic compounds in anaerobic environments (Larson and Weber, 1994). Proposed reductants cover a spectrum ranging from reduced rninerals and organic matter to microbial enzyme systems. Transfo...

  11. A fungal metallo-beta-lactamase necessary for biotransformation of maize phytoprotectant compounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Xenobiotic compounds such as phytochemicals, microbial metabolites, and agrochemicals can impact the diversity and frequency of fungal species occurring in agricultural environments. Resistance to xenobiotics may allow plant pathogenic fungi to dominate the overall fungal community, with potential ...

  12. The Impact of Microbial Metabolism on Marine Dissolved Organic Matter

    NASA Astrophysics Data System (ADS)

    Kujawinski, Elizabeth B.

    2011-01-01

    Microbes mediate global biogeochemical cycles through their metabolism, and all metabolic processes begin with the interaction between the microbial cell wall or membrane and the external environment. For all heterotrophs and many autotrophs, critical growth substrates and factors are present within the dilute and heterogeneous mixture of compounds that constitutes dissolved organic matter (DOM). In short, the microbe-molecule interaction is one of the fundamental reactions within the global carbon cycle. Here, I summarize recent findings from studies that examine DOM-microbe interactions from either the DOM perspective (organic geochemistry) or the microbe perspective (microbial ecology). Gaps in our knowledge are highlighted and future integrative research directions are proposed.

  13. Effects of Ga substitution on the structural and magnetic properties of half metallic Fe2MnSi Heusler compound

    NASA Astrophysics Data System (ADS)

    Pedro, S. S.; Caraballo Vivas, R. J.; Andrade, V. M.; Cruz, C.; Paixão, L. S.; Contreras, C.; Costa-Soares, T.; Caldeira, L.; Coelho, A. A.; Carvalho, A. Magnus G.; Rocco, D. L.; Reis, M. S.

    2015-01-01

    The so-called half-metallic magnets have been proposed as good candidates for spintronic applications due to the feature of exhibiting a hundred percent spin polarization at the Fermi level. Such materials follow the Slater-Pauling rule, which relates the magnetic moment with the valence electrons in the system. In this paper, we study the bulk polycrystalline half-metallic Fe2MnSi Heusler compound replacing Si by Ga to determine how the Ga addition changes the magnetic, the structural, and the half-metal properties of this compound. The material does not follow the Slater-Pauling rule, probably due to a minor structural disorder degree in the system, but a linear dependence on the magnetic transition temperature with the valence electron number points to the half-metallic behavior of this compound.

  14. Application of microbiological methods for waste-compound degradation

    SciTech Connect

    Schmauder, H.P.; Ludwig, M.; Zeth, R.; Guenther, K.; Schlosser, D.

    1995-12-31

    To develop processes for decontaminating lipophilic waste compounds in water or soil, several methods were investigated based on applying free or immobilized microbial cells, as well as mediators of the solubility of lipophilic substances or mixtures. Degradation of hydrocarbons and phenolic compounds (e.g., phenol, o-, m-, and p-cresol) in the groundwater of an industrial area and preliminary investigations of the degradation of volatile halogenated hydrocarbons (model compound trichloroethylene, TCE) using these methods are described. The microorganisms used were Bacillus pumilus (degradation of hydrocarbons and phenolic compounds) and strains isolated from contaminated soils.

  15. Evolution of microbial markets.

    PubMed

    Werner, Gijsbert D A; Strassmann, Joan E; Ivens, Aniek B F; Engelmoer, Daniel J P; Verbruggen, Erik; Queller, David C; Noë, Ronald; Johnson, Nancy Collins; Hammerstein, Peter; Kiers, E Toby

    2014-01-28

    Biological market theory has been used successfully to explain cooperative behavior in many animal species. Microbes also engage in cooperative behaviors, both with hosts and other microbes, that can be described in economic terms. However, a market approach is not traditionally used to analyze these interactions. Here, we extend the biological market framework to ask whether this theory is of use to evolutionary biologists studying microbes. We consider six economic strategies used by microbes to optimize their success in markets. We argue that an economic market framework is a useful tool to generate specific and interesting predictions about microbial interactions, including the evolution of partner discrimination, hoarding strategies, specialized versus diversified mutualistic services, and the role of spatial structures, such as flocks and consortia. There is untapped potential for studying the evolutionary dynamics of microbial systems. Market theory can help structure this potential by characterizing strategic investment of microbes across a diversity of conditions.

  16. 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.

  17. Microbial Genomes Multiply

    NASA Technical Reports Server (NTRS)

    Doolittle, Russell F.

    2002-01-01

    The publication of the first complete sequence of a bacterial genome in 1995 was a signal event, underscored by the fact that the article has been cited more than 2,100 times during the intervening seven years. It was a marvelous technical achievement, made possible by automatic DNA-sequencing machines. The feat is the more impressive in that complete genome sequencing has now been adopted in many different laboratories around the world. Four years ago in these columns I examined the situation after a dozen microbial genomes had been completed. Now, with upwards of 60 microbial genome sequences determined and twice that many in progress, it seems reasonable to assess just what is being learned. Are new concepts emerging about how cells work? Have there been practical benefits in the fields of medicine and agriculture? Is it feasible to determine the genomic sequence of every bacterial species on Earth? The answers to these questions maybe Yes, Perhaps, and No, respectively.

  18. Microbial Risk Assessment

    NASA Technical Reports Server (NTRS)

    Ott, C. M.; Mena, K. D.; Nickerson, C.A.; Pierson, D. L.

    2009-01-01

    Historically, microbiological spaceflight requirements have been established in a subjective manner based upon expert opinion of both environmental and clinical monitoring results and the incidence of disease. The limited amount of data, especially from long-duration missions, has created very conservative requirements based primarily on the concentration of microorganisms. Periodic reevaluations of new data from later missions have allowed some relaxation of these stringent requirements. However, the requirements remain very conservative and subjective in nature, and the risk of crew illness due to infectious microorganisms is not well defined. The use of modeling techniques for microbial risk has been applied in the food and potable water industries and has exceptional potential for spaceflight applications. From a productivity standpoint, this type of modeling can (1) decrease unnecessary costs and resource usage and (2) prevent inadequate or inappropriate data for health assessment. In addition, a quantitative model has several advantages for risk management and communication. By identifying the variable components of the model and the knowledge associated with each component, this type of modeling can: (1) Systematically identify and close knowledge gaps, (2) Systematically identify acceptable and unacceptable risks, (3) Improve communication with stakeholders as to the reasons for resource use, and (4) Facilitate external scientific approval of the NASA requirements. The modeling of microbial risk involves the evaluation of several key factors including hazard identification, crew exposure assessment, dose-response assessment, and risk characterization. Many of these factors are similar to conditions found on Earth; however, the spaceflight environment is very specialized as the inhabitants live in a small, semi-closed environment that is often dependent on regenerative life support systems. To further complicate modeling efforts, microbial dose

  19. Evolution of microbial markets

    PubMed Central

    Werner, Gijsbert D. A.; Strassmann, Joan E.; Ivens, Aniek B. F.; Engelmoer, Daniel J. P.; Verbruggen, Erik; Queller, David C.; Noë, Ronald; Johnson, Nancy Collins; Hammerstein, Peter; Kiers, E. Toby

    2014-01-01

    Biological market theory has been used successfully to explain cooperative behavior in many animal species. Microbes also engage in cooperative behaviors, both with hosts and other microbes, that can be described in economic terms. However, a market approach is not traditionally used to analyze these interactions. Here, we extend the biological market framework to ask whether this theory is of use to evolutionary biologists studying microbes. We consider six economic strategies used by microbes to optimize their success in markets. We argue that an economic market framework is a useful tool to generate specific and interesting predictions about microbial interactions, including the evolution of partner discrimination, hoarding strategies, specialized versus diversified mutualistic services, and the role of spatial structures, such as flocks and consortia. There is untapped potential for studying the evolutionary dynamics of microbial systems. Market theory can help structure this potential by characterizing strategic investment of microbes across a diversity of conditions. PMID:24474743

  20. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Chisholm, J.L.

    1992-03-01

    The objective of this project is to perform a microbial enhanced oil recovery field pilot in the Southeast Vassar Vertz Sand Unit (SEVVSU) in Payne County, Oklahoma. Indigenous, anaerobic, nitrate reducing bacteria will be stimulated to selectively plug flow paths which have been referentially swept by a prior waterflood. This will force future flood water to invade bypassed regions of the reservoir and increase sweep efficiency. This report covers progress made during the second year, January 1, 1990 to December 31, 1990, of the Microbial Field Pilot Study project. Information on reservoir ecology, surface facilities design, operation of the unit, core experiments, modeling of microbial processes, and reservoir characterization and simulation are presented in the report. To better understand the ecology of the target reservoir, additional analyses of the fluids which support bacteriological growth and the microbiology of the reservoir were performed. The results of the produced and injected water analysis show increasing sulfide concentrations with respect to time. In March of 1990 Mesa Limited Partnership sold their interest in the SEVVSU to Sullivan and Company. In April, Sullivan and Company assumed operation of the field. The facilities for the field operation of the pilot were refined and implementation was begun. Core flood experiments conducted during the last year were used to help define possible mechanisms involved in microbial enhanced oil recovery. The experiments were performed at SEVVSU temperature using fluids and inoculum from the unit. The model described in last year's report was further validated using results from a core flood experiment. The model was able to simulate the results of one of the core flood experiments with good quality.

  1. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Chisholm, J.L.

    1992-03-01

    The objective of this project is to perform a microbial enhanced oil recovery field pilot in the Southeast Vassar Vertz Sand Unit (SEVVSU) in Payne County, Oklahoma. Indigenous, anaerobic, nitrate reducing bacteria will be stimulated to selectively plug flow paths which have been referentially swept by a prior waterflood. This will force future flood water to invade bypassed regions of the reservoir and increase sweep efficiency. This report covers progress made during the second year, January 1, 1990 to December 31, 1990, of the Microbial Field Pilot Study project. Information on reservoir ecology, surface facilities design, operation of the unit, core experiments, modeling of microbial processes, and reservoir characterization and simulation are presented in the report. To better understand the ecology of the target reservoir, additional analyses of the fluids which support bacteriological growth and the microbiology of the reservoir were performed. The results of the produced and injected water analysis show increasing sulfide concentrations with respect to time. In March of 1990 Mesa Limited Partnership sold their interest in the SEVVSU to Sullivan and Company. In April, Sullivan and Company assumed operation of the field. The facilities for the field operation of the pilot were refined and implementation was begun. Core flood experiments conducted during the last year were used to help define possible mechanisms involved in microbial enhanced oil recovery. The experiments were performed at SEVVSU temperature using fluids and inoculum from the unit. The model described in last year`s report was further validated using results from a core flood experiment. The model was able to simulate the results of one of the core flood experiments with good quality.

  2. Automated Microbial Metabolism Laboratory

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Development of the automated microbial metabolism laboratory (AMML) concept is reported. The focus of effort of AMML was on the advanced labeled release experiment. Labeled substrates, inhibitors, and temperatures were investigated to establish a comparative biochemical profile. Profiles at three time intervals on soil and pure cultures of bacteria isolated from soil were prepared to establish a complete library. The development of a strategy for the return of a soil sample from Mars is also reported.

  3. Advances in microbial amylases.

    PubMed

    Pandey, A; Nigam, P; Soccol, C R; Soccol, V T; Singh, D; Mohan, R

    2000-04-01

    This review makes a comprehensive survey of microbial amylases, i.e. alpha-amylase, beta-amylase and glucoamylase. Amylases are among the most important enzymes and are of great significance in present-day biotechnology. Although they can be derived from several sources, such as plants, animals and micro-organisms, the enzymes from microbial sources generally meet industrial demands. Microbial amylases could be potentially useful in the pharmaceutical and fine-chemical industries if enzymes with suitable properties could be prepared. With the advent of new frontiers in biotechnology, the spectrum of amylase application has widened in many other fields, such as clinical, medicinal and analytical chemistries, as well as their widespread application in starch saccharification and in the textile, food, brewing and distilling industries. In this review, after a brief description of the sources of amylases, we discuss the molecular biology of amylases, describing structures, cloning, sequences, and protoplast fusion and mutagenesis. This is followed by sections on their production and finally the properties of various amylases.

  4. Pathogenesis of microbial keratitis.

    PubMed

    Lakhundi, Sahreena; Siddiqui, Ruqaiyyah; Khan, Naveed Ahmed

    2017-03-01

    Microbial keratitis is a sight-threatening ocular infection caused by bacteria, fungi, and protist pathogens. Epithelial defects and injuries are key predisposing factors making the eye susceptible to corneal pathogens. Among bacterial pathogens, the most common agents responsible for keratitis include Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pneumonia and Serratia species. Fungal agents of corneal infections include both filamentous as well as yeast, including Fusarium, Aspergillus, Phaeohyphomycetes, Curvularia, Paecilomyces, Scedosporium and Candida species, while in protists, Acanthamoeba spp. are responsible for causing ocular disease. Clinical features include redness, pain, tearing, blur vision and inflammation but symptoms vary depending on the causative agent. The underlying molecular mechanisms associated with microbial pathogenesis include virulence factors as well as the host factors that aid in the progression of keratitis, resulting in damage to the ocular tissue. The treatment therefore should focus not only on the elimination of the culprit but also on the neutralization of virulence factors to minimize the damage, in addition to repairing the damaged tissue. A complete understanding of the pathogenesis of microbial keratitis will lead to the rational development of therapeutic interventions. This is a timely review of our current understanding of the advances made in this field in a comprehensible manner. Coupled with the recently available genome sequence information and high throughput genomics technology, and the availability of innovative approaches, this will stimulate interest in this field.

  5. Microbial reduction of iodate

    USGS Publications Warehouse

    Councell, T.B.; Landa, E.R.; Lovley, D.R.

    1997-01-01

    The different oxidation species of iodine have markedly different sorption properties. Hence, changes in iodine redox states can greatly affect the mobility of iodine in the environment. Although a major microbial role has been suggested in the past to account for these redox changes, little has been done to elucidate the responsible microorganisms or the mechanisms involved. In the work presented here, direct microbial reduction of iodate was demonstrated with anaerobic cell suspensions of the sulfate reducing bacterium Desulfovibrio desulfuricans which reduced 96% of an initial 100 ??M iodate to iodide at pH 7 in 30 mM NaHCO3 buffer, whereas anaerobic cell suspensions of the dissimilatory Fe(III)-reducing bacterium Shewanella putrefaciens were unable to reduce iodate in 30 mM NaHCO3 buffer (pH 7). Both D. desulfuricans and S. putrefaciens were able to reduce iodate at pH 7 in 10 mM HEPES buffer. Both soluble ferrous iron and sulfide, as well as iron monosulfide (FeS) were shown to abiologically reduce iodate to iodide. These results indicate that ferric iron and/or sulfate reducing bacteria are capable of mediating both direct, enzymatic, as well as abiotic reduction of iodate in natural anaerobic environments. These microbially mediated reactions may be important factors in the fate and transport of 129I in natural systems.

  6. Microbial biosurfactants and biodegradation.

    PubMed

    Ward, Owen P

    2010-01-01

    Microbial biosurfactants are amphipathic molecules having typical molecular weights of 500-1500 Da, made up of peptides, saccharides or lipids or their combinations. In biodegradation processes they mediate solubilisation, mobilization and/or accession of hydrophobic substrates to microbes. They may be located on the cell surface or be secreted into the extracellular medium and they facilitate uptake of hydrophobic molecules through direct cellular contact with hydrophobic solids or droplets or through micellarisation. They are also involved in cell physiological processes such as biofilm formation and detachment, and in diverse biofilm associated processes such as wastewater treatment and microbial pathogenesis. The protection of contaminants in biosurfactants micelles may also inhibit uptake of contaminants by microbes. In bioremediation processes biosurfactants may facilitate release of contaminants from soil, but soils also tend to bind surfactants strongly which makes their role in contaminant desorption more complex. A greater understanding of the underlying roles played by biosurfactants in microbial physiology and in biodegradative processes is developing through advances in cell and molecular biology.

  7. Diversity of microbial communities of Loki's Castle black smoker field at the ultra-slow spreading Arctic Mid-Ocean Ridge

    NASA Astrophysics Data System (ADS)

    Jaeschke, A.; Bernasconi, S. M.; Thorseth, I. H.; Pedersen, R.; Früh-Green, G.

    2010-12-01

    Here we present an organic geochemical study of Loki’s Castle, a black smoker field recently discovered at the Arctic Mid-Ocean Ridge (AMOR) in the Norwegian-Greenland Sea at around 73.2°N. Located at the Mohn-Knipovich Ridge, which is one of the slowest spreading ridge segments on Earth, Loki’s Castle is the most northerly major hydrothermal vent field known to date. The vent field is composed of five actively venting (320°C) black-smoker chimneys that tower on top of a large mound of hydrothermal sulfide deposits. Loki’s Castle is a basalt-hosted hydrothermal system, but high methane and ammonium contents in the vent fluids strongly indicate a sedimentary component below the volcanic ridge. In 2009, another site of low-temperature hydrothermal venting hosting numerous barite chimneys was discovered in the vicinity of the black smokers, which probably results from subsurface mixing of diffuse hydrothermal fluid with seawater. In our study, variations in microbial communities associated with the formation of actively venting, sulfide and sulfate chimneys in this essentially unexplored ultraslow spreading ridge system are assessed based on biomarker lipid and compound-specific carbon isotope analyses. Lipid extracts from an active, high-temperature sulfide chimney yielded abundant archaeal di- and tetraether lipids as well as irregular isoprenoidal hydrocarbons (PMIs) that are associated with archaeal methanogens and methanotrophs. Predominant archaeal biomarker lipids include archaeol, sn-2-hydroxyarchaeol as well as glycerol dialkyl glycerol tetraethers (GDGTs) containing 0-4 cyclopentyl moieties. In addition, GDGTs with an additional covalent bond between the isoprenoid hydrocarbon chains, so-called H-shaped GDGTs, containing 0-4 cyclopentyl rings were also found to be abundant components and are indicative of hyperthermophilic methanogens. Biomarkers characteristic of eukaryotes (sterols) and bacteria (fatty acids and hopanoids) were less prevalent in

  8. Microbial biofilms on building stone

    NASA Astrophysics Data System (ADS)

    Hoppert, M.; Kemmling, A.; Kämper, M.

    2003-04-01

    Microbial biofilms are ubiquitous in aquatic and terrestric ecosystems as well as on man-made material. The organisms take part in biogenic weathering on natural rocks as well as on building stone [1]. Though the presence of biofilms on stone monuments exposed to the outdoor environment is obvious, thin films also occur on monuments under controllable indoor environment conditions. Numerous biofilm organisms produce large volumes of extracellular polymer (EP), mainly polysaccharides. Hydrated, gel-like EP acts as glue between the organisms and the material surface and forms a protected environment for the microbial cells. The contact zone between EP and the material surface is the crucial reactive interface of the bio-organic cover and the underlying building material. At this interface, all hazardous compounds (e.g. organic acids), after diffusion transfer via EP, react with the material surface. Upon dehydration, volume of EP greatly decreases. The thin, varnish-like EP layer still protects the dormant cells from irreversible inactivation. Periodic shrinking and swelling of the EP induces mechanical stress on the stone surface, epecially when the polymer penetrates small pores and cavities in the underlying material surface. Thus, monitoring and structure/functional analysis of EP and EP production by organisms is important to understand biogenic weathering phenomena and building stone deterioration. The study presented here describes biofilms on the surfaces of building material in outdoor and indoor environments. The application of marker techniques and visualization of samples with light and electron microscopy illustrates the role of EP at microscale. EP forms the matrix that encloses microorganisms, dust particles and mineral grains in a rigid film. EP penetrates small pore spaces of the underlying substratum and may also facilitate subsequent penetration of the microorganisms into the material. EP seals the material surface and cements the superficial layer

  9. Microbial Formaldehyde Oxidation

    SciTech Connect

    Timothy J. Donohue

    2004-12-09

    This project analyzed how cells sense and generate energy from formaldehyde oxidation. Formaldehyde is a toxin that is produced naturally, chemically or by metabolism of a wide variety of methyl-containing compounds. Our goals are to identify how cells sense the presence of this toxic compound and determine how they generate energy and nutrients from the oxidation of formaldehyde. This research capitalizes on the role of the Rhodobacter sphaeroides glutathione dependent formaldehyde dehydrogenase (GSH FDH) in a formaldehyde oxidation pathway that is apparently found in a wide variety of microbes, plants and animals. Thus, our findings illustrate what is required for a large variety of cells to metabolize this toxic compound. A second major focus of our research is to determine how cells sense the presence of this toxic compound and control the expression of gene products required for its detoxification.

  10. Microbial diversity, producer-decomposer interactions and ecosystem processes: a theoretical model.

    PubMed

    Loreau, M

    2001-02-07

    Interactions between the diversity of primary producers and that of decomposers--the two key functional groups that form the basis of all ecosystems--might have major consequences on the functioning of depauperate ecosystems. I present a simple ecosystem model in which primary producers (plants) and decomposers (microbes) are linked through material cycling. The model considers a diversity of plant organic compounds and a diversity of microbial species. Nutrient recycling efficiency from organic compounds to decomposers is then the key parameter that controls ecosystem processes (primary productivity, secondary productivity, producer biomass and decomposer biomass). The model predicts that microbial diversity has a positive effect on nutrient recycling efficiency and ecosystem processes through either greater intensity of microbial exploitation of organic compounds or functional niche complementarity, much like in plants. Microbial niche breadth and overlap should not affect ecosystem processes unless they increase the number of organic compounds that are decomposed. In contrast, the model predicts that plant organic compound diversity can only have a negative effect or, at best, no effect on ecosystem processes, at least in a constant environment. This creates a tension between the effects of plant diversity and microbial diversity on ecosystem functioning, which may explain some recent experimental results.

  11. Bioactive berry compounds-novel tools against human pathogens.

    PubMed

    Puupponen-Pimiä, Riitta; Nohynek, Liisa; Alakomi, Hanna-Leena; Oksman-Caldentey, Kirsi-Marja

    2005-04-01

    Berry fruits are rich sources of bioactive compounds, such as phenolics and organic acids, which have antimicrobial activities against human pathogens. Among different berries and berry phenolics, cranberry, cloudberry, raspberry, strawberry and bilberry especially possess clear antimicrobial effects against, e.g. Salmonella and Staphylococcus. Complex phenolic polymers, like ellagitannins, are strong antibacterial agents present in cloudberry and raspberry. Several mechanisms of action in the growth inhibition of bacteria are involved, such as destabilisation of cytoplasmic membrane, permeabilisation of plasma membrane, inhibition of extracellular microbial enzymes, direct actions on microbial metabolism and deprivation of the substrates required for microbial growth. Antimicrobial activity of berries may also be related to antiadherence of bacteria to epithelial cells, which is a prerequisite for colonisation and infection of many pathogens. Antimicrobial berry compounds may have important applications in the future as natural antimicrobial agents for food industry as well as for medicine. Some of the novel approaches are discussed.

  12. Microbial reductive dehalogenation.

    PubMed Central

    Mohn, W W; Tiedje, J M

    1992-01-01

    A wide variety of compounds can be biodegraded via reductive removal of halogen substituents. This process can degrade toxic pollutants, some of which are not known to be biodegraded by any other means. Reductive dehalogenation of aromatic compounds has been found primarily in undefined, syntrophic anaerobic communities. We discuss ecological and physiological principles which appear to be important in these communities and evaluate how widely applicable these principles are. Anaerobic communities that catalyze reductive dehalogenation appear to differ in many respects. A large number of pure cultures which catalyze reductive dehalogenation of aliphatic compounds are known, in contrast to only a few organisms which catalyze reductive dehalogenation of aromatic compounds. Desulfomonile tiedjei DCB-1 is an anaerobe which dehalogenates aromatic compounds and is physiologically and morphologically unusual in a number of respects, including the ability to exploit reductive dehalogenation for energy metabolism. When possible, we use D. tiedjei as a model to understand dehalogenating organisms in the above-mentioned undefined systems. Aerobes use reductive dehalogenation for substrates which are resistant to known mechanisms of oxidative attack. Reductive dehalogenation, especially of aliphatic compounds, has recently been found in cell-free systems. These systems give us an insight into how and why microorganisms catalyze this activity. In some cases transition metal complexes serve as catalysts, whereas in other cases, particularly with aromatic substrates, the catalysts appear to be enzymes. Images PMID:1406492

  13. Microbial carbon turnover in the plant-rhizosphere-soil continuum

    NASA Astrophysics Data System (ADS)

    Malik, Ashish; Dannert, Helena; Griffiths, Robert; Thomson, Bruce; Gleixner, Gerd

    2014-05-01

    Soil microbial biomass contributes significantly to maintenance of soil organic matter (SOM). It is well known that biochemical fractions of soil microorganisms have varying turnover and therefore contribute differentially to soil C storage. Here we compare the turnover rates of different microbial biochemical fractions using a pulse chase 13CO2 plant labelling experiment. The isotope signal was temporally traced into rhizosphere soil microorganisms using the following biomarkers: DNA, RNA, fatty acids and chloroform fumigation extraction derived microbial biomass size classes. C flow into soil microbial functional groups was assessed through phospholipid and neutral lipid fatty acid (PLFA/NLFA) analyses. Highest 13C enrichment was seen in the low molecular weight (LMW) size class of microbial biomass (Δδ13C =151) and in nucleic acids (DNA: 38o RNA: 66) immediately after the pulse followed by a sharp drop. The amount of 13C in the high molecular weight (HMW) microbial biomass (17-81) and total fatty acids (32-54) was lower initially and stayed relatively steady over the 4 weeks experimental period. We found significant differences in turnover rates of different microbial biochemical and size fractions. We infer that LMW cytosolic soluble compounds are rapidly metabolized and linked to respiratory C fluxes, whereas mid-sized products of microbial degradation and HMW polymeric compounds have lower renewal rate in that order. The turnover of cell wall fatty acids was also very slow. DNA and RNA showed faster turnover rate; and as expected RNA renewal was the fastest due to its rapid production by active microorganisms independent of cell replication. 13C incorporation into different functional groups confirmed that mutualistic arbuscular mycorrhizal fungi rely on root C and are important in the initial plant C flux. We substantiated through measurements of isotope incorporation into bacterial RNA that rhizosphere bacteria are also important in the initial C conduit

  14. Qualitative analysis of volatile organic compounds on biochar

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Qualitative identification of sorbed volatile organic compounds (VOCs) on biochar was conducted by headspace thermal desorption coupled to capillary gas chromatographic-mass spectrometry. VOCs may have a mechanistic role influencing plant and microbial responses to biochar amendments, since VOCs ca...

  15. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Coates, J.D.; Chisholm, J.L.

    1993-05-01

    A multi-well microbially enhanced oil recovery field pilot has been performed in the Southeast Vassar Vertz Sand Unit in Payne County, Oklahoma. The primary emphasis of the experiment was preferential plugging of high permeability zones for the purpose of improving waterflood sweep efficiency. Studies were performed to determine reservoir chemistry, ecology, and indigenous bacteria populations. Growth experiments were used to select a nutrient system compatible with the reservoir that encouraged growth of a group of indigenous nitrate-using bacteria and inhibit growth of sulfate-reducing bacteria. A specific field pilot area behind an active line drive waterflood was selected. Surface facilities were designed and installed. Injection protocols of bulk nutrient materials were prepared to facilitate uniform distribution of nutrients within the pilot area. By the end of December, 1991, 82.5 tons (75.0 tonnes) of nutrients had been injected in the field. A tracer test identified significant heterogeneity in the SEVVSU and made it necessary to monitor additional production wells in the field. The tracer tests and changes in production behavior indicate the additional production wells monitored during the field trial were also affected. Eighty two and one half barrels (13.1 m[sup 3]) of tertiary oil have been recovered. Microbial activity has increased CO[sub 2] content as indicated by increased alkalinity. A temporary rise in sulfide concentration was experienced. These indicate an active microbial community was generated in the field by the nutrient injection. Pilot area interwell pressure interference test results showed that significant permeability reduction occurred. The interwell permeabilities in the pilot area between the injector and the three pilot production wells were made more uniform which indicates a successful preferential plugging enhanced oil recovery project.

  16. Microbial metabolism of Tholin

    NASA Technical Reports Server (NTRS)

    Stoker, C. R.; Mancinelli, R. L.; Boston, P. J.; Segal, W.; Khare, B. N.

    1990-01-01

    Tholin, a class of complex organic heteropolymers hypothesized to possess wide solar system distribution, is shown to furnish the carbon and energy requirements of a wide variety of common soil bacteria which encompasses aerobic, anaerobic, and facultatively anaerobic bacteria. Some of these bacteria are able to derive not merely their carbon but also their nitrogen requirements from tholin. The palatability of tholins to modern microbes is speculated to have implications for the early evolution of microbial life on earth; tholins may have formed the base of the food chain for an early heterotrophic biosphere, prior to the evolution of autotrophy on the early earth.

  17. 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.

  18. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.

    1991-12-06

    The objective of this project is to perform a microbial enhanced oil recovery field pilot test in the Southeast Vassar Vertz Sand Unit (SEVVSU) in Payne County, Oklahoma. Indigenous, anaerobic, nitrate-reducing bacteria will be stimulated to selectively plug flow paths which have been preferentially swept by a prior waterflood. This will force future flood water to invade bypassed regions of the reservoir and increase sweep efficiency. During this quarter an additional tracer study was performed in the field to determine pre-treatment flow paths and the first nutrients were injected. 2 figs.

  19. [Microbial diffusion and antibiotherapy].

    PubMed

    Vilain, R

    1982-01-01

    Cleaning leg ulcers depends on tissular and microbial enzymes, the production of which depends on good vascularization. When an aetiological treatment is started, the microbes ensure sufficient cleaning, leading to granulation and epidermization. Antibiotherapy is pointless. Sometimes it can be detrimental, replacing a natural growth with alien strains which cause diffusion. Very exceptionally, a short course of antibiotherapy may be necessary to cope with signs of diffusion, usually signifying a Group A streptococcal infection, with seasonal recrudescence. The Blue Pus Microbe has no special pathological significance. It merely indicates that the case has become chronic.

  20. 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.

  1. Bayesian Integrated Microbial Forensics

    SciTech Connect

    Jarman, Kristin H.; Kreuzer-Martin, Helen W.; Wunschel, David S.; Valentine, Nancy B.; Cliff, John B.; Petersen, Catherine E.; Colburn, Heather A.; Wahl, Karen L.

    2008-06-01

    In the aftermath of the 2001 anthrax letters, researchers have been exploring ways to predict the production environment of unknown source microorganisms. Different mass spectral techniques are being developed to characterize components of a microbe’s culture medium including water, carbon and nitrogen sources, metal ions added, and the presence of agar. Individually, each technique has the potential to identify one or two ingredients in a culture medium recipe. However, by integrating data from multiple mass spectral techniques, a more complete characterization is possible. We present a Bayesian statistical approach to integrated microbial forensics and illustrate its application on spores grown in different culture media.

  2. Microbial bebop: creating music from complex dynamics in microbial ecology.

    PubMed

    Larsen, Peter; Gilbert, Jack

    2013-01-01

    In order for society to make effective policy decisions on complex and far-reaching subjects, such as appropriate responses to global climate change, scientists must effectively communicate complex results to the non-scientifically specialized public. However, there are few ways however to transform highly complicated scientific data into formats that are engaging to the general community. Taking inspiration from patterns observed in nature and from some of the principles of jazz bebop improvisation, we have generated Microbial Bebop, a method by which microbial environmental data are transformed into music. Microbial Bebop uses meter, pitch, duration, and harmony to highlight the relationships between multiple data types in complex biological datasets. We use a comprehensive microbial ecology, time course dataset collected at the L4 marine monitoring station in the Western English Channel as an example of microbial ecological data that can be transformed into music. Four compositions were generated (www.bio.anl.gov/MicrobialBebop.htm.) from L4 Station data using Microbial Bebop. Each composition, though deriving from the same dataset, is created to highlight different relationships between environmental conditions and microbial community structure. The approach presented here can be applied to a wide variety of complex biological datasets.

  3. The use of Yucca schidigera and microbial preparation for poultry manure deodorization and hygienization.

    PubMed

    Matusiak, Katarzyna; Oleksy, Magdalena; Borowski, Sebastian; Nowak, Adriana; Korczyński, Mariusz; Dobrzański, Zbigniew; Gutarowska, Beata

    2016-04-01

    The aim of this study was to determine the effectiveness of microbial preparation and Yucca schidigera in the removal of odorous volatile compounds from poultry manure as well as to evaluate antimicrobial properties of these amendments. It was demonstrated that the combined treatment of poultry manure (PM) with the microbial preparation and Y. schidigera extract can reduce the concentration of odorants by 58%-73%, depending on the tested compound. When Y. schidigera extract and the microbial preparation were applied at a time interval of 48 h, the deodorization efficiency was improved by 6-24%. Furthermore, Y. schidigera extract has antimicrobial properties, which affect poultry manure hygienization. It was found that when the microbial preparation was enriched with Lactobacillus plantarum, it became insensitive to the antimicrobial properties of Y. schidigera.

  4. [Strategies on the construction of high-quality microbial natural product library--a review].

    PubMed

    Bian, Jiang; Song, Fuhang; Zhang, Lixin

    2008-08-01

    The microbial secondary metabolites are always the main source of the natural drugs. The historical paradigm of the deep ocean as a biological 'desert' has shifted to one of a 'rainforest' owing to the isolation of many novel microbes and their associated bioactive compounds. A high quality microbial and its natural product library are crucial for successful drug and other screenings. However, how to build up the library efficiently is still faced with many bottlenecks. To overcome the difficulties and limitations, we reviewed the following strategies: (1) diversifying microbial sources and dereplication; (2) diversifying gene sources and dereplication; (3) diversifying microbial metabolite sources and dereplication; (4) novel methods and technologies for bioactive secondary metabolites, especially the high-throughput synergy screening for multi-target drugs. Bioactive compounds isolated using the above chemical microbiology strategies have not only shown importance in biotechnological and pharmaceutical applications but also increased our understanding of the diversity of microbe, ecosystem functions and the exploitable biology.

  5. Uranium Biomineralization By Natural Microbial Phosphatase Activities in the Subsurface

    SciTech Connect

    Taillefert, Martial

    2015-04-01

    This project investigated the geochemical and microbial processes associated with the biomineralization of radionuclides in subsurface soils. During this study, it was determined that microbial communities from the Oak Ridge Field Research subsurface are able to express phosphatase activities that hydrolyze exogenous organophosphate compounds and result in the non-reductive bioimmobilization of U(VI) phosphate minerals in both aerobic and anaerobic conditions. The changes of the microbial community structure associated with the biomineralization of U(VI) was determined to identify the main organisms involved in the biomineralization process, and the complete genome of two isolates was sequenced. In addition, it was determined that both phytate, the main source of natural organophosphate compounds in natural environments, and polyphosphate accumulated in cells could also be hydrolyzed by native microbial population to liberate enough orthophosphate and precipitate uranium phosphate minerals. Finally, the minerals produced during this process are stable in low pH conditions or environments where the production of dissolved inorganic carbon is moderate. These findings suggest that the biomineralization of U(VI) phosphate minerals is an attractive bioremediation strategy to uranium bioreduction in low pH uranium-contaminated environments. These efforts support the goals of the SBR long-term performance measure by providing key information on "biological processes influencing the form and mobility of DOE contaminants in the subsurface".

  6. Possibilities for the Detection of Microbial Life on Extrasolar Planets

    NASA Astrophysics Data System (ADS)

    Knacke, Roger F.

    2003-11-01

    We consider possibilities for the remote detection of microbial life on extrasolar planets. The Darwin/Terrestrial Planet Finder (TPF) telescope concepts for observations of terrestrial planets focus on indirect searches for life through the detection of atmospheric gases related to life processes. Direct detection of extraterrestrial life may also be possible through well-designed searches for microbial life forms. Satellites in Earth orbit routinely monitor colonies of terrestrial algae in oceans and lakes by analysis of reflected ocean light in the visible region of the spectrum. These remote sensing techniques suggest strategies for extrasolar searches for signatures of chlorophylls and related photosynthetic compounds associated with life. However, identification of such life-related compounds on extrasolar planets would require observations through strong, interfering absorptions and scattering radiances from the remote atmospheres and landmasses. Techniques for removal of interfering radiances have been extensively developed for remote sensing from Earth orbit. Comparable techniques would have to be developed for extrasolar planet observations also, but doing so would be challenging for a remote planet. Darwin/TPF coronagraph concepts operating in the visible seem to be best suited for searches for extrasolar microbial life forms with instruments that can be projected for the 2010-2020 decades, although resolution and signal-to-noise ratio constraints severely limit detection possibilities on terrestrial-type planets. The generation of telescopes with large apertures and extremely high spatial resolutions that will follow Darwin/TPF could offer striking possibilities for the direct detection of extrasolar microbial life.

  7. Possibilities for the detection of microbial life on extrasolar planets.

    PubMed

    Knacke, Roger F

    2003-01-01

    We consider possibilities for the remote detection of microbial life on extrasolar planets. The Darwin/Terrestrial Planet Finder (TPF) telescope concepts for observations of terrestrial planets focus on indirect searches for life through the detection of atmospheric gases related to life processes. Direct detection of extraterrestrial life may also be possible through well-designed searches for microbial life forms. Satellites in Earth orbit routinely monitor colonies of terrestrial algae in oceans and lakes by analysis of reflected ocean light in the visible region of the spectrum. These remote sensing techniques suggest strategies for extrasolar searches for signatures of chlorophylls and related photosynthetic compounds associated with life. However, identification of such life-related compounds on extrasolar planets would require observations through strong, interfering absorptions and scattering radiances from the remote atmospheres and landmasses. Techniques for removal of interfering radiances have been extensively developed for remote sensing from Earth orbit. Comparable techniques would have to be developed for extrasolar planet observations also, but doing so would be challenging for a remote planet. Darwin/TPF coronagraph concepts operating in the visible seem to be best suited for searches for extrasolar microbial life forms with instruments that can be projected for the 2010-2020 decades, although resolution and signal-to-noise ratio constraints severely limit detection possibilities on terrestrial-type planets. The generation of telescopes with large apertures and extremely high spatial resolutions that will follow Darwin/TPF could offer striking possibilities for the direct detection of extrasolar microbial life.

  8. Microbial enzymes: industrial progress in 21st century.

    PubMed

    Singh, Rajendra; Kumar, Manoj; Mittal, Anshumali; Mehta, Praveen Kumar

    2016-12-01

    Biocatalytic potential of microorganisms have been employed for centuries to produce bread, wine, vinegar and other common products without understanding the biochemical basis of their ingredients. Microbial enzymes have gained interest for their widespread uses in industries and medicine owing to their stability, catalytic activity, and ease of production and optimization than plant and animal enzymes. The use of enzymes in various industries (e.g., food, agriculture, chemicals, and pharmaceuticals) is increasing rapidly due to reduced processing time, low energy input, cost effectiveness, nontoxic and eco-friendly characteristics. Microbial enzymes are capable of degrading toxic chemical compounds of industrial and domestic wastes (phenolic compounds, nitriles, amines etc.) either via degradation or conversion. Here in this review, we highlight and discuss current technical and scientific involvement of microorganisms in enzyme production and their present status in worldwide enzyme market.

  9. Deposition of biogenic iron minerals in a methane oxidizing microbial mat.

    PubMed

    Wrede, Christoph; Kokoschka, Sebastian; Dreier, Anne; Heller, Christina; Reitner, Joachim; Hoppert, Michael

    2013-01-01

    The syntrophic community between anaerobic methanotrophic archaea and sulfate reducing bacteria forms thick, black layers within multi-layered microbial mats in chimney-like carbonate concretions of methane seeps located in the Black Sea Crimean shelf. The microbial consortium conducts anaerobic oxidation of methane, which leads to the formation of mainly two biomineral by-products, calcium carbonates and iron sulfides, building up these chimneys. Iron sulfides are generated by the microbial reduction of oxidized sulfur compounds in the microbial mats. Here we show that sulfate reducing bacteria deposit biogenic iron sulfides extra- and intracellularly, the latter in magnetosome-like chains. These chains appear to be stable after cell lysis and tend to attach to cell debris within the microbial mat. The particles may be important nuclei for larger iron sulfide mineral aggregates.

  10. An efficient magnetically modified microbial cell biocomposite for carbazole biodegradation

    NASA Astrophysics Data System (ADS)

    Li, Yufei; Du, Xiaoyu; Wu, Chao; Liu, Xueying; Wang, Xia; Xu, Ping

    2013-12-01

    Magnetic modification of microbial cells enables to prepare smart biocomposites in bioremediation. In this study, we constructed an efficient biocomposite by assembling Fe3O4 nanoparticles onto the surface of Sphingomonas sp. XLDN2-5 cells. The average particle size of Fe3O4 nanoparticles was about 20 nm with 45.5 emu g-1 saturation magnetization. The morphology of Sphingomonas sp. XLDN2-5 cells before and after Fe3O4 nanoparticle loading was verified by scanning electron microscopy and transmission electronic microscopy. Compared with free cells, the microbial cell/Fe3O4 biocomposite had the same biodegradation activity but exhibited remarkable reusability. The degradation activity of the microbial cell/Fe3O4 biocomposite increased gradually during recycling processes. Additionally, the microbial cell/Fe3O4 biocomposite could be easily separated and recycled by an external magnetic field due to the super-paramagnetic properties of Fe3O4 nanoparticle coating. These results indicated that magnetically modified microbial cells provide a promising technique for improving biocatalysts used in the biodegradation of hazardous compounds.

  11. Microbial Biogeography and Core Microbiota of the Rat Digestive Tract

    PubMed Central

    Li, Dongyao; Chen, Haiqin; Mao, Bingyong; Yang, Qin; Zhao, Jianxin; Gu, Zhennan; Zhang, Hao; Chen, Yong Q.; Chen, Wei

    2017-01-01

    As a long-standing biomedical model, rats have been frequently used in studies exploring the correlations between gastrointestinal (GI) bacterial biota and diseases. In the present study, luminal and mucosal samples taken along the longitudinal axis of the rat digestive tract were subjected to 16S rRNA gene sequencing-based analysis to determine the baseline microbial composition. Results showed that the community diversity increased from the upper to lower GI segments and that the stratification of microbial communities as well as shift of microbial metabolites were driven by biogeographic location. A greater proportion of lactate-producing bacteria (such as Lactobacillus, Turicibacter and Streptococcus) were found in the stomach and small intestine, while anaerobic Lachnospiraceae and Ruminococcaceae, fermenting carbohydrates and plant aromatic compounds, constituted the bulk of the large-intestinal core microbiota where topologically distinct co-occurrence networks were constructed for the adjacent luminal and mucosal compartments. When comparing the GI microbiota from different hosts, we found that the rat microbial biogeography might represent a new reference, distinct from other murine animals. Our study provides the first comprehensive characterization of the rat GI microbiota landscape for the research community, laying the foundation for better understanding and predicting the disease-related alterations in microbial communities. PMID:28374781

  12. An efficient magnetically modified microbial cell biocomposite for carbazole biodegradation

    PubMed Central

    2013-01-01

    Magnetic modification of microbial cells enables to prepare smart biocomposites in bioremediation. In this study, we constructed an efficient biocomposite by assembling Fe3O4 nanoparticles onto the surface of Sphingomonas sp. XLDN2-5 cells. The average particle size of Fe3O4 nanoparticles was about 20 nm with 45.5 emu g-1 saturation magnetization. The morphology of Sphingomonas sp. XLDN2-5 cells before and after Fe3O4 nanoparticle loading was verified by scanning electron microscopy and transmission electronic microscopy. Compared with free cells, the microbial cell/Fe3O4 biocomposite had the same biodegradation activity but exhibited remarkable reusability. The degradation activity of the microbial cell/Fe3O4 biocomposite increased gradually during recycling processes. Additionally, the microbial cell/Fe3O4 biocomposite could be easily separated and recycled by an external magnetic field due to the super-paramagnetic properties of Fe3O4 nanoparticle coating. These results indicated that magnetically modified microbial cells provide a promising technique for improving biocatalysts used in the biodegradation of hazardous compounds. PMID:24330511

  13. Molecular biology of microbial ureases.

    PubMed Central

    Mobley, H L; Island, M D; Hausinger, R P

    1995-01-01

    Urease (urea amidohydrolase; EC 3.5.1.5) catalyzes the hydrolysis of urea to yield ammonia and carbamate. The latter compound spontaneously decomposes to yield another molecule of ammonia and carbonic acid. The urease phenotype is widely distributed across the bacterial kingdom, and the gene clusters encoding this enzyme have been cloned from numerous bacterial species. The complete nucleotide sequence, ranging from 5.15 to 6.45 kb, has been determined for five species including Bacillus sp. strain TB-90, Klebsiella aerogenes, Proteus mirabilis, Helicobacter pylori, and Yersinia enterocolitica. Sequences for selected genes have been determined for at least 10 other bacterial species and the jack bean enzyme. Urease synthesis can be nitrogen regulated, urea inducible, or constitutive. The crystal structure of the K. aerogenes enzyme has been determined. When combined with chemical modification studies, biophysical and spectroscopic analyses, site-directed mutagenesis results, and kinetic inhibition experiments, the structure provides important insight into the mechanism of catalysis. Synthesis of active enzyme requires incorporation of both carbon dioxide and nickel ions into the protein. Accessory genes have been shown to be required for activation of urease apoprotein, and roles for the accessory proteins in metallocenter assembly have been proposed. Urease is central to the virulence of P. mirabilis and H. pylori. Urea hydrolysis by P. mirabilis in the urinary tract leads directly to urolithiasis (stone formation) and contributes to the development of acute pyelonephritis. The urease of H. pylori is necessary for colonization of the gastric mucosa in experimental animal models of gastritis and serves as the major antigen and diagnostic marker for gastritis and peptic ulcer disease in humans. In addition, the urease of Y. enterocolitica has been implicated as an arthritogenic factor in the development of infection-induced reactive arthritis. The significant

  14. Overview of microbial biofilms.

    PubMed

    Costerton, J W

    1995-09-01

    As the success of this two-issue special section of the Journal of Industrial Microbiology attests, the study of microbial biofilms is truly burgeoning as the uniqueness and the importance of this mode of growth is increasingly recognized. Because of its universality the biofilm concept impacts virtually all of the subdivisions of Microbiology (including Medical, Dental, Agricultural, Industrial and Environmental) and these two issues incorporate contributions from authors in all of these disciplines. Some time ago we reasoned that bacteria cannot possibly be aware (sic) of their precise location, in terms of this spectrum of anthrocentric subspecialties, and that their behavior must be dictated by a standard set of phenotypic responses to environmental conditions in what must seem to them (sic) to be a continuum of very similar aquatic ecosystems. In this overview I will, therefore, stress the common features of microbial biofilms that we should bear in mind as we use this simple universal concept to seek to understand bacterial behavior in literally hundreds of aquatic ecosystems traditionally studied by dozens of subspecies of microbiologists reared in sharply different scientific and academic conventions.

  15. Microbial interactions during carrion decomposition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This addresses the microbial ecology of carrion decomposition in the age of metagenomics. It describes what is known about the microbial communities on carrion, including a brief synopsis about the communities on other organic matter sources. It provides a description of studies using state-of-the...

  16. Compositions of constructed microbial mats

    DOEpatents

    Bender, Judith A.; Phillips, Peter C.

    1999-01-01

    Compositions and methods of use of constructed microbial mats, comprising cyanobacteria and purple autotrophic bacteria and an organic nutrient source, in a laminated structure, are described. The constructed microbial mat is used for bioremediation of different individual contaminants and for mixed or multiple contaminants, and for production of beneficial compositions and molecules.

  17. The Promise of Microbial Technology.

    ERIC Educational Resources Information Center

    El Nawawy, Amin S.

    1982-01-01

    Prospects for microbial technology are discussed including: (1) possible transfer of nitrogen-fixing ability directly from bacteria to plant; (2) increasing food needs met through single-cell proteins and fermentation; (3) microbial production of antibiotics; and (4) increased biogas production. (Author/JN)

  18. Microbial chemical factories: recent advances in pathway engineering for synthesis of value added chemicals.

    PubMed

    Dhamankar, Himanshu; Prather, Kristala L J

    2011-08-01

    The dwindling nature of petroleum and other fossil reserves has provided impetus towards microbial synthesis of fuels and value added chemicals from biomass-derived sugars as a renewable resource. Microbes have naturally evolved enzymes and pathways that can convert biomass into hundreds of unique chemical structures, a property that can be effectively exploited for their engineering into Microbial Chemical Factories (MCFs). De novo pathway engineering facilitates expansion of the repertoire of microbially synthesized compounds beyond natural products. In this review, we visit some recent successes in such novel pathway engineering and optimization, with particular emphasis on the selection and engineering of pathway enzymes and balancing of their accessory cofactors.

  19. Toxicity of vapor phase petroleum contaminants to microbial degrader communities

    SciTech Connect

    Long, S.C.; Davey, C.A.

    1994-12-31

    Petroleum products constitute the largest quantity of synthetic organic chemical products produced in the US. They are comprised of mostly hydrocarbon constituents from many different chemical classes including alkenes, cycloalkanes, aromatic compounds, and polyaromatic hydrocarbons. Many petroleum constituents are classified as volatile organic compounds or VOCs. Petroleum products also constitute a major portion of environmental pollution. One emerging technology, with promise for applications to VOCs in subsurface soil environments, is bioventing coupled with soil vapor extraction. These technologies involve volatilization of contaminants into the soil gas phase by injection and withdrawal of air. This air movement causes enhancement of the aerobic microbial degradation of the mobilized vapors by the indigenous populations. This study investigated the effects of exposure of mixed, subsurface microbial communities to vapor phase petroleum constituents or vapors of petroleum mixtures. Soil slurries were prepared and plated onto mineral salts agar plates and exposed to vapor phase contaminants at equilibrium with pure product. Representative n-alkane, branched alkane, cycloalkane, and aromatic compounds were tested as well as petroleum product mixtures. Vapor exposure altered the numbers and morphologies of the colonies enumerated when compared to controls. However, even at high, equilibrium vapor concentrations, microbial degrader populations were not completely inhibited.

  20. Oxidation of aromatic contaminants coupled to microbial iron reduction

    USGS Publications Warehouse

    Lovley, D.R.; Baedecker, M.J.; Lonergan, D.J.; Cozzarelli, I.M.; Phillips, E.J.P.; Siegel, D.I.

    1989-01-01

    THE contamination of sub-surface water supplies with aromatic compounds is a significant environmental concern1,2. As these contaminated sub-surface environments are generally anaerobic, the microbial oxidation of aromatic compounds coupled to nitrate reduction, sulphate reduction and methane production has been studied intensively1-7. In addition, geochemical evidence suggests that Fe(III) can be an important electron acceptor for the oxidation of aromatic compounds in anaerobic groundwater. Until now, only abiological mechanisms for the oxidation of aromatic compounds with Fe(III) have been reported8-12. Here we show that in aquatic sediments, microbial activity is necessary for the oxidation of model aromatic compounds coupled to Fe(III) reduction. Furthermore, a pure culture of the Fe(III)-reducing bacterium GS-15 can obtain energy for growth by oxidizing benzoate, toluene, phenol or p-cresol with Fe(III) as the sole electron acceptor. These results extend the known physiological capabilities of Fe(III)-reducing organisms and provide the first example of an organism of any type which can oxidize an aromatic hydrocarbon anaerobically. ?? 1989 Nature Publishing Group.

  1. Microbial production of natural raspberry ketone.

    PubMed

    Beekwilder, Jules; van der Meer, Ingrid M; Sibbesen, Ole; Broekgaarden, Mans; Qvist, Ingmar; Mikkelsen, Joern D; Hall, Robert D

    2007-10-01

    Raspberry ketone is an important compound for the flavour industry. It is frequently used in products such as soft drinks, sweets, puddings and ice creams. The compound can be produced by organic synthesis. Demand for "natural" raspberry ketone is growing considerably. However, this product is extremely expensive. Consequently, there is a remaining desire to better understand how raspberry ketone is synthesized in vivo, and which genes and enzymes are involved. With this information we will then be in a better position to design alternative production strategies such as microbial fermentation. This article focuses on the identification and application of genes potentially linked to raspberry ketone synthesis. We have isolated candidate genes from both raspberry and other plants, and these have been introduced into bacterial and yeast expression systems. Conditions have been determined that result in significant levels of raspberry ketone, up to 5 mg/L. These results therefore lay a strong foundation for a potentially renewable source of "natural" flavour compounds making use of plant genes.

  2. Encapsulation of a model compound in pectin delays its release from a biobased polymeric material

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A model compound was encapsulated in pectin and then extruded with thermoplastic starch to form a composite. The intended product was a food-contact tray made of biobased polymers infused with an anti-microbial agent; however, caffeine was used as the model compound in the preliminary work. The mode...

  3. Analysis of phenolic compounds for poultry feed by supercritical fluid chromatography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phenolic compounds have generated interest as components in functional feed formulations due to their anti-oxidant, anti-microbial, and anti-fungal properties. These compounds may have greater significance in the future as the routine use of antibiotics is reduced and the prevalence of resistant bac...

  4. High-throughput screening to identify selective inhibitors of microbial sulfate reduction (and beyond)

    NASA Astrophysics Data System (ADS)

    Carlson, H. K.; Coates, J. D.; Deutschbauer, A. M.

    2015-12-01

    The selective perturbation of complex microbial ecosystems to predictably influence outcomes in engineered and industrial environments remains a grand challenge for geomicrobiology. In some industrial ecosystems, such as oil reservoirs, sulfate reducing microorganisms (SRM) produce hydrogen sulfide which is toxic, explosive and corrosive. Current strategies to selectively inhibit sulfidogenesis are based on non-specific biocide treatments, bio-competitive exclusion by alternative electron acceptors or sulfate-analogs which are competitive inhibitors or futile/alternative substrates of the sulfate reduction pathway. Despite the economic cost of sulfidogenesis, there has been minimal exploration of the chemical space of possible inhibitory compounds, and very little work has quantitatively assessed the selectivity of putative souring treatments. We have developed a high-throughput screening strategy to target SRM, quantitatively ranked the selectivity and potency of hundreds of compounds and identified previously unrecognized SRM selective inhibitors and synergistic interactions between inhibitors. Once inhibitor selectivity is defined, high-throughput characterization of microbial community structure across compound gradients and identification of fitness determinants using isolate bar-coded transposon mutant libraries can give insights into the genetic mechanisms whereby compounds structure microbial communities. The high-throughput (HT) approach we present can be readily applied to target SRM in diverse environments and more broadly, could be used to identify and quantify the potency and selectivity of inhibitors of a variety of microbial metabolisms. Our findings and approach are relevant for engineering environmental ecosystems and also to understand the role of natural gradients in shaping microbial niche space.

  5. Diversity of Microbial Carbohydrate-Active enZYmes (CAZYmes) Associated with Freshwater and Soil Samples from Caatinga Biome.

    PubMed

    Andrade, Ana Camila; Fróes, Adriana; Lopes, Fabyano Álvares Cardoso; Thompson, Fabiano L; Krüger, Ricardo Henrique; Dinsdale, Elizabeth; Bruce, Thiago

    2017-01-09

    Semi-arid and arid areas occupy about 33% of terrestrial ecosystems. However, little information is available about microbial diversity in the semi-arid Caatinga, which represents a unique biome that extends to about 11% of the Brazilian territory and is home to extraordinary diversity and high endemism level of species. In this study, we characterized the diversity of microbial genes associated with biomass conversion (carbohydrate-active enzymes, or so-called CAZYmes) in soil and freshwater of the Caatinga. Our results showed distinct CAZYme profiles in the soil and freshwater samples. Glycoside hydrolases and glycosyltransferases were the most abundant CAZYme families, with glycoside hydrolases more dominant in soil (∼44%) and glycosyltransferases more abundant in freshwater (∼50%). The abundances of individual glycoside hydrolase, glycosyltransferase, and carbohydrate-binding module subfamilies varied widely between soil and water samples. A predominance of glycoside hydrolases was observed in soil, and a higher contribution of enzymes involved in carbohydrate biosynthesis was observed in freshwater. The main taxa associated with the CAZYme sequences were Planctomycetia (relative abundance in soil, 29%) and Alphaproteobacteria (relative abundance in freshwater, 27%). Approximately 5-7% of CAZYme sequences showed low similarity with sequences deposited in non-redundant databases, suggesting putative homologues. Our findings represent a first attempt to describe specific microbial CAZYme profiles for environmental samples. Characterizing these enzyme groups associated with the conversion of carbohydrates in nature will improve our understanding of the significant roles of enzymes in the carbon cycle. We identified a CAZYme signature that can be used to discriminate between soil and freshwater samples, and this signature may be related to the microbial species adapted to the habitat. The data show the potential ecological roles of the CAZYme repertoire and

  6. CO2 sequestration by ureolytic microbial consortia through microbially-induced calcite precipitation.

    PubMed

    Okyay, Tugba O; Nguyen, Hang N; Castro, Sarah L; Rodrigues, Debora F

    2016-12-01

    Urea is an abundant nitrogen-containing compound found in urine of mammals and widely used in fertilizers. This compound is part of the nitrogen biogeochemical cycle and is easily biodegraded by ureolytic microorganisms that have the urease enzyme. Previous studies, with ureolytic isolates, have shown that some ureolytic microorganisms are able to sequester CO2 through a process called microbially-induced calcium carbonate precipitation. The present study investigates 15 ureolytic consortia obtained from the "Pamukkale travertines" and the "Cave Without A Name" using different growth media to identify the possible bacterial genera responsible for CO2 sequestration through the microbially-induced calcite precipitation (MICP). The community structure and diversity were determined by deep-sequencing. The results showed that all consortia presented varying CO2 sequestration capabilities and MICP rates. The CO2 sequestration varied between 0 and 86.4%, and it depended largely on the community structure, as well as on pH. Consortia with predominance of Comamonas, Plesiomonas and Oxalobacter presented reduced CO2 sequestration. On the other hand, consortia dominated by Sporosarcina, Sphingobacterium, Stenotrophomonas, Acinetobacter, and Elizabethkingia showed higher rates of CO2 uptake in the serum bottle headspace.

  7. New microbial growth factor

    NASA Technical Reports Server (NTRS)

    Bok, S. H.; Casida, L. E., Jr.

    1977-01-01

    A screening procedure was used to isolate from soil a Penicillium sp., two bacterial isolates, and a Streptomyces sp. that produced a previously unknown microbial growth factor. This factor was an absolute growth requirement for three soil bacteria. The Penicillium sp. and one of the bacteria requiring the factor, an Arthrobacter sp., were selected for more extensive study concerning the production and characteristics of the growth factor. It did not seem to be related to the siderochromes. It was not present in soil extract, rumen fluid, or any other medium component tested. It appears to be a glycoprotein of high molecular weight and has high specific activity. When added to the diets for a meadow-vole mammalian test system, it caused an increased consumption of diet without a concurrent increase in rate of weight gain.

  8. Microbial load monitor

    NASA Technical Reports Server (NTRS)

    Caplin, R. S.; Royer, E. R.

    1978-01-01

    Attempts are made to provide a total design of a Microbial Load Monitor (MLM) system flight engineering model. Activities include assembly and testing of Sample Receiving and Card Loading Devices (SRCLDs), operator related software, and testing of biological samples in the MLM. Progress was made in assembling SRCLDs with minimal leaks and which operate reliably in the Sample Loading System. Seven operator commands are used to control various aspects of the MLM such as calibrating and reading the incubating reading head, setting the clock and reading time, and status of Card. Testing of the instrument, both in hardware and biologically, was performed. Hardware testing concentrated on SRCLDs. Biological testing covered 66 clinical and seeded samples. Tentative thresholds were set and media performance listed.

  9. Microbial fuel cells

    SciTech Connect

    Nealson, Kenneth H; Pirbazari, Massoud; Hsu, Lewis

    2013-04-09

    A microbial fuel cell includes an anode compartment with an anode and an anode biocatalyst and a cathode compartment with a cathode and a cathode biocatalyst, with a membrane positioned between the anode compartment and the cathode compartment, and an electrical pathway between the anode and the cathode. The anode biocatalyst is capable of catalyzing oxidation of an organic substance, and the cathode biocatalyst is capable of catalyzing reduction of an inorganic substance. The reduced organic substance can form a precipitate, thereby removing the inorganic substance from solution. In some cases, the anode biocatalyst is capable of catalyzing oxidation of an inorganic substance, and the cathode biocatalyst is capable of catalyzing reduction of an organic or inorganic substance.

  10. Drinking water microbial myths.

    PubMed

    Allen, Martin J; Edberg, Stephen C; Clancy, Jennifer L; Hrudey, Steve E

    2015-01-01

    Accounts of drinking water-borne disease outbreaks have always captured the interest of the public, elected and health officials, and the media. During the twentieth century, the drinking water community and public health organizations have endeavored to craft regulations and guidelines on treatment and management practices that reduce risks from drinking water, specifically human pathogens. During this period there also evolved misunderstandings as to potential health risk associated with microorganisms that may be present in drinking waters. These misunderstanding or "myths" have led to confusion among the many stakeholders. The purpose of this article is to provide a scientific- and clinically-based discussion of these "myths" and recommendations for better ensuring the microbial safety of drinking water and valid public health decisions.

  11. Microbial Field Pilot Study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Chisholm, J.L.

    1990-11-01

    This report covers progress made during the first year of the Microbial Field Pilot Study project. Information on reservoir ecology and characterization, facility and treatment design, core experiments, bacterial mobility, and mathematical modeling are addressed. To facilitate an understanding of the ecology of the target reservoir analyses of the fluids which support bacteriological growth and the microbiology of the reservoir were performed. A preliminary design of facilities for the operation of the field pilot test was prepared. In addition, procedures for facilities installation and for injection treatments are described. The Southeast Vassar Vertz Sand Unit (SEVVSU), the site of the proposed field pilot study, is described physically, historically, and geologically. The fields current status is presented and the ongoing reservoir simulation is discussed. Core flood experiments conducted during the last year were used to help define possible mechanisms involved in microbial enhanced oil recovery. Two possible mechanisms, relative permeability effects and changes in the capillary number, are discussed and related to four Berea core experiments' results. The experiments were conducted at reservoir temperature using SEVVSU oil, brine, and bacteria. The movement and activity of bacteria in porous media were investigated by monitoring the growth of bacteria in sandpack cores under no flow conditions. The rate of bacteria advancement through the cores was determined. A mathematical model of the MEOR process has been developed. The model is a three phase, seven species, one dimensional model. Finite difference methods are used for solution. Advection terms in balance equations are represented with a third- order upwind differencing scheme to reduce numerical dispersion and oscillations. The model is applied to a batch fermentation example. 52 refs., 26 figs., 21 tabs.

  12. Role of oxidants in microbial pathophysiology.

    PubMed Central

    Miller, R A; Britigan, B E

    1997-01-01

    Reactive oxidant species (superoxide, hydrogen peroxide, hydroxyl radical, hypohalous acid, and nitric oxide) are involved in many of the complex interactions between the invading microorganism and its host. Regardless of the source of these compounds or whether they are produced under normal conditions or those of oxidative stress, these oxidants exhibit a broad range of toxic effects to biomolecules that are essential for cell survival. Production of these oxidants by microorganisms enables them to have a survival advantage in their environment. Host oxidant production, especially by phagocytes, is a counteractive mechanism aimed at microbial killing. However, this mechanism may be contribute to a deleterious consequence of oxidant exposure, i.e., inflammatory tissue injury. Both the host and the microorganism have evolved complex adaptive mechanisms to deflect oxidant-mediated damage, including enzymatic and nonenzymatic oxidant-scavenging systems. This review discusses the formation of reactive oxidant species in vivo and how they mediate many of the processes involved in the complex interplay between microbial invasion and host defense. PMID:8993856

  13. Microbial populations in contaminant plumes

    USGS Publications Warehouse

    Haack, S.K.; Bekins, B.A.

    2000-01-01

    Efficient biodegradation of subsurface contaminants requires two elements: (1) microbial populations with the necessary degradative capabilities, and (2) favorable subsurface geochemical and hydrological conditions. Practical constraints on experimental design and interpretation in both the hydrogeological and microbiological sciences have resulted in limited knowledge of the interaction between hydrogeological and microbiological features of subsurface environments. These practical constraints include: (1) inconsistencies between the scales of investigation in the hydrogeological and microbiological sciences, and (2) practical limitations on the ability to accurately define microbial populations in environmental samples. However, advances in application of small-scale sampling methods and interdisciplinary approaches to site investigations are beginning to significantly improve understanding of hydrogeological and microbiological interactions. Likewise, culture-based and molecular analyses of microbial populations in subsurface contaminant plumes have revealed significant adaptation of microbial populations to plume environmental conditions. Results of recent studies suggest that variability in subsurface geochemical and hydrological conditions significantly influences subsurface microbial-community structure. Combined investigations of site conditions and microbial-community structure provide the knowledge needed to understand interactions between subsurface microbial populations, plume geochemistry, and contaminant biodegradation.

  14. 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.

  15. Impact of androgenic/antiandrogenic compounds (AAC) on human sex steroid metabolizing key enzymes.

    PubMed

    Alléra, A; Lo, S; King, I; Steglich, F; Klingmüller, D

    2004-12-01

    Various pesticides, industrial pollutants and synthetic compounds, to which human populations are exposed, are known or suspected to interfere with endogenous sex hormone functions. Such interference potentially affect the development and expression of the male and female reproductive system or both. Chemicals in this class are thus referred to as endocrine disruptors (ED). This emphazises on the relevance of screening ED for a wide range of sex hormone-mimicking effects. These compounds are believed to exert influence on hormonal actions predominantly by (i) interfering with endogenous steroids in that they functionally interact with plasma membrane-located receptors as well as with nuclear receptors both for estrogens and androgens or (ii) affecting the levels of sex hormones as a result of their impact on steroid metabolizing key enzymes. Essential sex hormone-related enzymes within the endocrine system of humans are aromatase, 5alpha-reductase 2 as well as specific sulfotransferases and sulfatases (so-called phase I and phase II enzymes, respectively). Using suitable human tissues and human cancer cell lines (placenta, prostate, liver and JEG-3, lymph node carcinoma of prostate (LnCaP) cells) we investigated the impact of 10 widely used chemicals suspected of acting as ED with androgenic or antiandrogenic activity (so-called AAC) on the activity of these sex hormone metabolizing key enzymes in humans. In addition, the respective effects of six substances were also studied as positive controls due to their well-known specific hormonal agonistic/antagonistic activities. The aim of this report and subsequent investigations is to improve human health risk assessment for AAC and other ED.

  16. Limited recovery of soil microbial activity after transient exposure to gasoline vapors.

    PubMed

    Modrzyński, Jakub J; Christensen, Jan H; Mayer, Philipp; Brandt, Kristian K

    2016-09-01

    During gasoline spills complex mixtures of toxic volatile organic compounds (VOCs) are released to terrestrial environments. Gasoline VOCs exert baseline toxicity (narcosis) and may thus broadly affect soil biota. We assessed the functional resilience (i.e. resistance and recovery of microbial functions) in soil microbial communities transiently exposed to gasoline vapors by passive dosing via headspace for 40 days followed by a recovery phase of 84 days. Chemical exposure was characterized with GC-MS, whereas microbial activity was monitored as soil respiration (CO2 release) and soil bacterial growth ([(3)H]leucine incorporation). Microbial activity was strongly stimulated and inhibited at low and high exposure levels, respectively. Microbial growth efficiency decreased with increasing exposure, but rebounded during the recovery phase for low-dose treatments. Although benzene, toluene, ethylbenzene and xylene (BTEX) concentrations decreased by 83-97% during the recovery phase, microbial activity in high-dose treatments did not recover and numbers of viable bacteria were 3-4 orders of magnitude lower than in control soil. Re-inoculation with active soil microorganisms failed to restore microbial activity indicating residual soil toxicity, which could not be attributed to BTEX, but rather to mixture toxicity of more persistent gasoline constituents or degradation products. Our results indicate a limited potential for functional recovery of soil microbial communities after transient exposure to high, but environmentally relevant, levels of gasoline VOCs which therefore may compromise ecosystem services provided by microorganisms even after extensive soil VOC dissipation.

  17. The effect of raw milk microbial flora on the sensory characteristics of Salers-type cheeses.

    PubMed

    Callon, C; Berdagué, J L; Dufour, E; Montel, M C

    2005-11-01

    The sensory characteristics of Salers Protected Denomination of Origin raw-milk cheeses are linked to the biochemical composition of the raw material (milk) and to the resultant microbial community. To evaluate the influence of the microbial community on sensory characteristics, Salers-type cheeses were manufactured with the same pasteurized milk, reinoculated with 3 different microbial communities from 3 different filtrates from microfiltered milks. Each cheese was subjected to microbial counts (on selective media), biochemical tests, and volatile and sensory component analyses at different times of ripening. Adding different microbial communities to specimens of the same (biochemically identical) pasteurized milk lead to different sensory characteristics of the cheeses. Cheeses with fresh cream, hazelnut, and caramel attributes were opposed to those with fermented cream, chemical, and garlic flavors. The aromatic compounds identified (esters, acids, alcohols, and aldehydes) in these cheeses were quite similar. Nevertheless, one milk was distinguished by a higher content of acetoin, and lower 2-butanone and 3-methylpentanone concentrations. Over the production period of 1 mo, the different cheeses were characterized by the same balance of the microbial population assessed by microbial counts on different media. This was associated with the stability of some sensory attributes describing these cheeses. Nevertheless, there was no linear correlation between microbial flora data and sensory characteristics as measured in this study.

  18. [Soil microbial ecological process and microbial functional gene diversity].

    PubMed

    Zhang, Jing; Zhang, Huiwen; Li, Xinyu; Su, Zhencheng; Zhang, Chenggang

    2006-06-01

    Soil microbes in terrestrial ecosystem carry out a series of important ecological functions, such as geo-chemical cycling of elements, degradation of pollutants, and buffering to the acute changes of environment, etc. Soil microbial ecological function has a close relation with soil function, and the changes in the structure and composition of soil microbial populations can directly affect the realization of soil function. Through their produced enzymes, soil microbes take part in a series of metabolic activities, and the functional genes of coded enzymes are the functional markers of microbes. In recent ten years, molecular ecology focusing on the functional gene diversity has been developed rapidly, which gives us a new cut-in point to understand soil microbial ecological function from the point of functional gene. This paper reviewed the research advances in the functional gene diversity correlated to soil microbial ecological function, with the perspectives in this field discussed.

  19. Effects of Ga substitution on the structural and magnetic properties of half metallic Fe{sub 2}MnSi Heusler compound

    SciTech Connect

    Pedro, S. S. Caraballo Vivas, R. J.; Andrade, V. M.; Cruz, C.; Paixão, L. S.; Contreras, C.; Costa-Soares, T.; Rocco, D. L.; Reis, M. S.; Caldeira, L.; Coelho, A. A.; Carvalho, A. Magnus G.

    2015-01-07

    The so-called half-metallic magnets have been proposed as good candidates for spintronic applications due to the feature of exhibiting a hundred percent spin polarization at the Fermi level. Such materials follow the Slater-Pauling rule, which relates the magnetic moment with the valence electrons in the system. In this paper, we study the bulk polycrystalline half-metallic Fe{sub 2}MnSi Heusler compound replacing Si by Ga to determine how the Ga addition changes the magnetic, the structural, and the half-metal properties of this compound. The material does not follow the Slater-Pauling rule, probably due to a minor structural disorder degree in the system, but a linear dependence on the magnetic transition temperature with the valence electron number points to the half-metallic behavior of this compound.

  20. Soil microbial diversity and activity as terroir elements of Sangiovese vineyards in the Chianti Classico region (Italy)

    NASA Astrophysics Data System (ADS)

    Fabiani, Arturo; Mocali, Stefano; Priori, Simone; Valboa, Giuseppe; Vignozzi, Nadia; Pellegrini, Sergio; Storchi, Paolo; Perria, Rita; Costantini, Edoardo

    2016-04-01

    Linking the uniqueness and quality of grapes and wine to the environment they are produced, based on the terroir concept, have recently become popular in many parts of world. The natural components of terroir are actually a set of processes, which together create a delicate equilibrium and regulation of its effect on products in both space and time. Climate, geology, geomorphology and soil are therefore the main environmental factors which make up the terroir effect on different scales. However, information on the impact of soil microbial communities on soil functions, grapevine plants and wine quality is still lacking. Thus, four of the most suitable areas (so called "cru") for the production of Sangiovese wine were chosen within the Barone Ricasoli farm of Brolio, the largest winery in the Chianti Classico area in central Italy: Fattoio, Miniera, Ceni and Colli-Agresto. Based on previous pedological and sensing technologies surveys, each area was further divided into two distinct homogeneous areas of about 1.5 ha called Basic Terroir Unit (UTB), which were monitored over 3 years (2012-2014) for the soil the chemical-physical variability (moisture, organic matter, nitrogen, potassium), the vineyard physiological status (water stress, grape production, characteristics of the grapes and wine) and the structure and activity of soil microbial communities (determined through DGGE, soil respiration and microbial biomass, respectively). The aim of the work was to assess the relationships among soil parameters and vine quality at intra- and inter- UTB level and, in particular, the potential impact of microbial composition and/or function on the terroir concept. The overall results highlighted a microbial community structure specific for each cru area and, in particular, associated to each UTB. Furthermore, microbial activity in Miniera and Ceni appeared to be positively related to Sangiovese quality, as determined through the Sangiovese Performance Index. However, except

  1. Compounds affecting cholesterol absorption

    NASA Technical Reports Server (NTRS)

    Hua, Duy H. (Inventor); Koo, Sung I. (Inventor); Noh, Sang K. (Inventor)

    2004-01-01

    A class of novel compounds is described for use in affecting lymphatic absorption of cholesterol. Compounds of particular interest are defined by Formula I: ##STR1## or a pharmaceutically acceptable salt thereof.

  2. Dinitroso and polynitroso compounds

    PubMed Central

    Gowenlock, Brian G.; Richter-Addo, George B.

    2005-01-01

    The growing interest in the chemistry of C-nitroso compounds (RN=O; R = alkyl or aryl group) is due in part to the recognition of their participation in various metabolic processes of nitrogen-containing compounds. C-Nitroso compounds have a rich organic chemistry in their own right, displaying interesting intra- and intermolecular dimerization processes and addition reactions with unsaturated compounds. In addition, they have a fascinating coordination chemistry. While most of the attention has been directed towards C-nitroso compounds containing a single –NO moiety, there is an emerging area of research dealing with dinitroso and polynitroso compounds. In this critical review, we present and discuss the synthetic routes and properties of these relatively unexplored dinitroso and polynitroso compounds, and suggest areas of further development involving these compounds. (126 references.) PMID:16100619

  3. The biogeochemistry of microbial mats, stromatolites and the ancient biosphere

    NASA Technical Reports Server (NTRS)

    Desmarais, D. J.; Canfield, D. E.

    1991-01-01

    Stromatolites offer an unparalleled geologic record of early life, because they constitute the oldest and most abundant recognizable remains of microbial ecosystems. Microbial mats are living homologs of stromatolites; thus, the physiology of the microbiota as well as the processes which create those features of mats (e.g., biomarker organic compounds, elemental and stable isotopic compositions) which are preserved in the ancient record. Observations of the carbon isotopic composition (delta C-13) of stromatolites and microbial mats were made and are consistent with the hypothesis that atmospheric CO2 concentrations have declined by at least one to two orders of magnitude during the past 2.5 Ga. Whereas delta C-13 values of carbonate carbon average about 0 permil during both the early and mid-Proterozoic, the delta C-13 values of stromatolitic organic matter increase from an average of -35 between 2.0 and 2.6 Ga ago to an average of about -28 about 1.0 Ga ago. Modern microbial mats in hypersaline environments have delta C-13 values typically in the range of -5 to -9, relative to an inorganic bicarbonate source at 0 permil. Both microbial mats and pur cultures of cyanobacteria grown in waters in near equilibrium with current atmospheric CO2 levels exhibit minimal discrimination against C-13. In contrast, hot spring cyanobacterial mats or cyanobacterial cultures grown under higher CO2 levels exhibit substantially greater discrimination. If care is taken to compare modern mats with stromatolites from comparable environments, it might be possible to estimate ancient levels of atmospheric CO2. In modern microbial mats, a tight coupling exists between photosynthetic organic carbon production and subsequent carbon oxidation, mostly by sulfate reduction. The rate of one process fuels a high rate of the other, with much of the sulfate reduction occurring within the same depth interval as oxygenic photosynthesis. Other aspects of this study are presented.

  4. The Diversity of Anti-Microbial Secondary Metabolites Produced by Fungal Endophytes: An Interdisciplinary Perspective

    PubMed Central

    Mousa, Walaa Kamel; Raizada, Manish N.

    2013-01-01

    Endophytes are microbes that inhabit host plants without causing disease and are reported to be reservoirs of metabolites that combat microbes and other pathogens. Here we review diverse classes of secondary metabolites, focusing on anti-microbial compounds, synthesized by fungal endophytes including terpenoids, alkaloids, phenylpropanoids, aliphatic compounds, polyketides, and peptides from the interdisciplinary perspectives of biochemistry, genetics, fungal biology, host plant biology, human and plant pathology. Several trends were apparent. First, host plants are often investigated for endophytes when there is prior indigenous knowledge concerning human medicinal uses (e.g., Chinese herbs). However, within their native ecosystems, and where investigated, endophytes were shown to produce compounds that target pathogens of the host plant. In a few examples, both fungal endophytes and their hosts were reported to produce the same compounds. Terpenoids and polyketides are the most purified anti-microbial secondary metabolites from endophytes, while flavonoids and lignans are rare. Examples are provided where fungal genes encoding anti-microbial compounds are clustered on chromosomes. As different genera of fungi can produce the same metabolite, genetic clustering may facilitate sharing of anti-microbial secondary metabolites between fungi. We discuss gaps in the literature and how more interdisciplinary research may lead to new opportunities to develop bio-based commercial products to combat global crop and human pathogens. PMID:23543048

  5. Microbial Cell Imaging

    SciTech Connect

    Doktycz, Mitchel John; Sullivan, Claretta; Mortensen, Ninell P; Allison, David P

    2011-01-01

    the maximum scan size (roughly 100 x 100 {mu}m) and the restricted movement of the cantilever in the Z (or height) direction. In most commercial AFMs, the Z range is restricted to roughly 10 {mu}m such that the height of cells to be imaged must be seriously considered. Nevertheless, AFM can provide structural-functional information at nanometer resolution and do so in physiologically relevant environments. Further, instrumentation for scanning probe microscopy continues to advance. Systems for high-speed imaging are becoming available, and techniques for looking inside the cells are being demonstrated. The ability to combine AFM with other imaging modalities is likely to have an even greater impact on microbiological studies. AFM studies of intact microbial cells started to appear in the literature in the 1990s. For example, AFM studies of Saccharomyces cerevisiae examined buddings cars after cell division and detailed changes related to cell growth processes. Also, the first AFM studies of bacterial biofilms appeared. In the late 1990s, AFM studies of intact fungal spores described clear changes in spore surfaces upon germination, and studies of individual bacterial cells were also described. These early bacterial imaging studies examined changes in bacterial morphology due to antimicrobial peptides exposure and bacterial adhesion properties. The majority of these early studies were carried out on dried samples and took advantage of the resolving power of AFM. The lack of cell mounting procedures presented an impediment for cell imaging studies. Subsequently, several approaches to mounting microbial cells have been developed, and these techniques are described later. Also highlighted are general considerations for microbial imaging and a description of some of the various applications of AFM to microbiology.

  6. Short AntiMicrobial Peptides (SAMPs) as a class of extraordinary promising therapeutic agents.

    PubMed

    Ramesh, Suhas; Govender, Thavendran; Kruger, Hendrik G; de la Torre, Beatriz G; Albericio, Fernando

    2016-07-01

    The emergence of multidrug resistant bacteria has a direct impact on global public health because of the reduced potency of existing antibiotics against pathogens. Hence, there is a pressing need for new drugs with different modes of action that can kill microorganisms. Antimicrobial peptides (AMPs) can be regarded as an alternative tool for this purpose because they are proven to have therapeutic effects with broad-spectrum activities. There are some hurdles in using AMPs as clinical candidates such as toxicity, lack of stability and high budgets required for manufacturing. This can be overcome by developing shorter and more easily accessible AMPs, the so-called Short AntiMicrobial Peptides (SAMPs) that contain between two and ten amino acid residues. These are emerging as an attractive class of therapeutic agents with high potential for clinical use and possessing multifunctional activities. In this review we attempted to compile those SAMPs that have exhibited biological properties which are believed to hold promise for the future. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.

  7. Exploring microbial dark matter to resolve the deep archaeal ancestry of eukaryotes

    DOE PAGES

    Saw, Jimmy H.; Spang, Anja; Zaremba-Niedzwiedzka, Katarzyna; ...

    2015-08-31

    The origin of eukaryotes represents an enigmatic puzzle, which is still lacking a number of essential pieces. Whereas it is currently accepted that the process of eukaryogenesis involved an interplay between a host cell and an alphaproteobacterial endosymbiont, we currently lack detailed information regarding the identity and nature of these players. A number of studies have provided increasing support for the emergence of the eukaryotic host cell from within the archaeal domain of life, displaying a specific affiliation with the archaeal TACK superphylum. Recent studies have shown that genomic exploration of yet-uncultivated archaea, the so-called archaeal 'dark matter', is ablemore » to provide unprecedented insights into the process of eukaryogenesis. Here, we provide an overview of state-of-the-art cultivation-independent approaches, and demonstrate how these methods were used to obtain draft genome sequences of several novel members of the TACK superphylum, including Lokiarchaeum, two representatives of the Miscellaneous Crenarchaeotal Group (Bathyarchaeota), and a Korarchaeum-related lineage. In conclusion, the maturation of cultivation-independent genomics approaches, as well as future developments in next-generation sequencing technologies, will revolutionize our current view of microbial evolution and diversity, and provide profound new insights into the early evolution of life, including the enigmatic origin of the eukaryotic cell.« less

  8. Chapter 2. From microbial products to novel drugs that target a multitude of disease indications.

    PubMed

    Marinelli, Flavia

    2009-01-01

    More than 20,000 bioactive, so-called microbial secondary metabolites are known. In nature, they can play many different roles as antibiotics, toxins, ionophores, bioregulators, and in intra- and interspecific signaling. Their most versatile producers are differentiating filamentous fungi and actinomycetes, followed by other bacteria such as Bacillus, Pseudomonas, Myxobacteria, and Cyanobacteria. From a biotechnological point of view, bioactive metabolites have been mainly studied as potential anti-infectives (antibacterials, antifungals, antivirals, and antiparasitics). Many of them, originally discovered for their antibiotic activity, were developed further to become leading anticancer drugs, immunosuppressive agents for organ transplantation, and successful pharmaceuticals targeting metabolic and cardiovascular diseases. Old and novel antitumor antibiotics can be divided into two groups spanning diverse chemical classes: those causing some damage to the DNA such as Mitomycins (quinones), Bleomycins (glycopeptides), Actinomycins (peptides), Anthracyclines (aromatic polyketides), Pentostatin (nucleoside), Enediynes (polyketides), and Rebeccamycin derivatives (indolocarbazole glycosides)-all produced by Streptomyces strains or related genera; and the group of tubulin-targeting molecules such as plant/fungal Taxanes (terpenes), myxobacterial Epothilones (macrocyclic polyketides), and the revisited Cryptophycins (peptolides) produced by cyanobacteria. Immunosuppressive agents used in clinical practice include Cyclosporin A (cyclopeptide) and an ester of Mycophenolic acid (small aromatic polyketide), both produced by fungi, and two streptomycete macrocyclic polyketides, Sirolimus (rapamycin) and Tacrolimus (FK506). Statins include a group of fungal polyketides (Compactin or Mevastatin, Lovastatin) and their derivatives, which specifically inhibit cholesterologenesis in liver, and represent the best-selling drugs. They have been used to prevent cardiovascular diseases.

  9. Exploring microbial dark matter to resolve the deep archaeal ancestry of eukaryotes

    SciTech Connect

    Saw, Jimmy H.; Spang, Anja; Zaremba-Niedzwiedzka, Katarzyna; Juzokaite, Lina; Dodsworth, Jeremy A.; Murugapiran, Senthil K.; Colman, Dan R.; Takacs-Vesbach, Cristina; Hedlund, Brian P.; Guy, Lionel; Ettema, Thijs J. G.

    2015-08-31

    The origin of eukaryotes represents an enigmatic puzzle, which is still lacking a number of essential pieces. Whereas it is currently accepted that the process of eukaryogenesis involved an interplay between a host cell and an alphaproteobacterial endosymbiont, we currently lack detailed information regarding the identity and nature of these players. A number of studies have provided increasing support for the emergence of the eukaryotic host cell from within the archaeal domain of life, displaying a specific affiliation with the archaeal TACK superphylum. Recent studies have shown that genomic exploration of yet-uncultivated archaea, the so-called archaeal 'dark matter', is able to provide unprecedented insights into the process of eukaryogenesis. Here, we provide an overview of state-of-the-art cultivation-independent approaches, and demonstrate how these methods were used to obtain draft genome sequences of several novel members of the TACK superphylum, including Lokiarchaeum, two representatives of the Miscellaneous Crenarchaeotal Group (Bathyarchaeota), and a Korarchaeum-related lineage. In conclusion, the maturation of cultivation-independent genomics approaches, as well as future developments in next-generation sequencing technologies, will revolutionize our current view of microbial evolution and diversity, and provide profound new insights into the early evolution of life, including the enigmatic origin of the eukaryotic cell.

  10. Exploring microbial dark matter to resolve the deep archaeal ancestry of eukaryotes.

    PubMed

    Saw, Jimmy H; Spang, Anja; Zaremba-Niedzwiedzka, Katarzyna; Juzokaite, Lina; Dodsworth, Jeremy A; Murugapiran, Senthil K; Colman, Dan R; Takacs-Vesbach, Cristina; Hedlund, Brian P; Guy, Lionel; Ettema, Thijs J G

    2015-09-26

    The origin of eukaryotes represents an enigmatic puzzle, which is still lacking a number of essential pieces. Whereas it is currently accepted that the process of eukaryogenesis involved an interplay between a host cell and an alphaproteobacterial endosymbiont, we currently lack detailed information regarding the identity and nature of these players. A number of studies have provided increasing support for the emergence of the eukaryotic host cell from within the archaeal domain of life, displaying a specific affiliation with the archaeal TACK superphylum. Recent studies have shown that genomic exploration of yet-uncultivated archaea, the so-called archaeal 'dark matter', is able to provide unprecedented insights into the process of eukaryogenesis. Here, we provide an overview of state-of-the-art cultivation-independent approaches, and demonstrate how these methods were used to obtain draft genome sequences of several novel members of the TACK superphylum, including Lokiarchaeum, two representatives of the Miscellaneous Crenarchaeotal Group (Bathyarchaeota), and a Korarchaeum-related lineage. The maturation of cultivation-independent genomics approaches, as well as future developments in next-generation sequencing technologies, will revolutionize our current view of microbial evolution and diversity, and provide profound new insights into the early evolution of life, including the enigmatic origin of the eukaryotic cell.

  11. Exploring microbial dark matter to resolve the deep archaeal ancestry of eukaryotes

    PubMed Central

    Saw, Jimmy H.; Spang, Anja; Zaremba-Niedzwiedzka, Katarzyna; Juzokaite, Lina; Dodsworth, Jeremy A.; Murugapiran, Senthil K.; Colman, Dan R.; Takacs-Vesbach, Cristina; Hedlund, Brian P.; Guy, Lionel; Ettema, Thijs J. G.

    2015-01-01

    The origin of eukaryotes represents an enigmatic puzzle, which is still lacking a number of essential pieces. Whereas it is currently accepted that the process of eukaryogenesis involved an interplay between a host cell and an alphaproteobacterial endosymbiont, we currently lack detailed information regarding the identity and nature of these players. A number of studies have provided increasing support for the emergence of the eukaryotic host cell from within the archaeal domain of life, displaying a specific affiliation with the archaeal TACK superphylum. Recent studies have shown that genomic exploration of yet-uncultivated archaea, the so-called archaeal ‘dark matter’, is able to provide unprecedented insights into the process of eukaryogenesis. Here, we provide an overview of state-of-the-art cultivation-independent approaches, and demonstrate how these methods were used to obtain draft genome sequences of several novel members of the TACK superphylum, including Lokiarchaeum, two representatives of the Miscellaneous Crenarchaeotal Group (Bathyarchaeota), and a Korarchaeum-related lineage. The maturation of cultivation-independent genomics approaches, as well as future developments in next-generation sequencing technologies, will revolutionize our current view of microbial evolution and diversity, and provide profound new insights into the early evolution of life, including the enigmatic origin of the eukaryotic cell. PMID:26323759

  12. Energy and power limits for microbial activity

    NASA Astrophysics Data System (ADS)

    LaRowe, D.; Amend, J.

    2014-12-01

    The goal of this presentation is to describe a quantitative framework for determining how energy limits microbial activity, biomass and, ultimately, biogeochemical processes. Although this model can be applied to any environment, its utility is demonstrated in marine sediments, which are an attractive test habitat because they encompass a broad spectrum of energy levels, varying amounts of biomass and are ubiquitous. The potential number of active microbial cells in Arkonas Basin (Baltic Sea) sediments are estimated as a function of depth by quantifying the amount of energy that is available to them and the rate at which it is supplied: power. The amount of power supplied per cubic centimeter of sediment is determined by calculating the Gibbs energy of fermentation and sulfate reduction in combination with the rate of particulate organic carbon, POC, degradation. The Reactive Continuum Model (Boudreau and Ruddick, 1991), RCM, is used to determine the rate at which POC is made available for microbial consumption. The RCM represents POC as containing a range of different types of organic compounds whose ability to be consumed by microorganisms varies as a function of the age of the sediment and on the distribution of compound types that were initially deposited. The sediment age model and RCM parameters determined by (Mogollon et al., 2012) are used. The power available for fermentation and sulfate reduction coupled to H2 and acetate oxidation varies from 10-8 W cm-3 at the sediment water interface to between 10-11 - 10-12 W cm-3 at 3.5 meters below the seafloor, mbsf. Using values of maintenance powers for each of these catabolic activities taken from the literature, the total number of active cells in these sediments similarly decreases from just less than 108 cell cm-3 at the SWI to 4.6 x 104 cells cm-3 at 3.5 mbsf. The number of moles of POC decreases from 2.6 x 10-5 to 9.5 x 10-6, also becoming more recalcitrant with depth. Boudreau, B. P. and Ruddick, B. R

  13. 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.

  14. Teaching Microbial Growth by Simulation.

    ERIC Educational Resources Information Center

    Ruiz, A. Fernandez; And Others

    1989-01-01

    Presented is a simulation program for Apple II computer which assays the effects of a series of variables on bacterial growth and interactions between microbial populations. Results of evaluation of the program with students are summarized. (CW)

  15. 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

  16. The Future of Microbial Genomics

    SciTech Connect

    Kyrpides, Nikos

    2010-06-02

    Nikos Kyrpides, head of the Genome Biology group at the DOE Joint Genome Institute discusses current challenges in the field of microbial genomics on June 2, 2010 at the "Sequencing, Finishing, Analysis in the Future" meeting in Santa Fe, NM

  17. Microbially mediated mineral carbonation

    NASA Astrophysics Data System (ADS)

    Power, I. M.; Wilson, S. A.; Dipple, G. M.; Southam, G.

    2010-12-01

    Mineral carbonation involves silicate dissolution and carbonate precipitation, which are both natural processes that microorganisms are able to mediate in near surface environments (Ferris et al., 1994; Eq. 1). (Ca,Mg)SiO3 + 2H2CO3 + H2O → (Ca,Mg)CO3 + H2O + H4SiO4 + O2 (1) Cyanobacteria are photoautotrophs with cell surface characteristics and metabolic processes involving inorganic carbon that can induce carbonate precipitation. This occurs partly by concentrating cations within their net-negative cell envelope and through the alkalinization of their microenvironment (Thompson & Ferris, 1990). Regions with mafic and ultramafic bedrock, such as near Atlin, British Columbia, Canada, represent the best potential sources of feedstocks for mineral carbonation. The hydromagnesite playas near Atlin are a natural biogeochemical model for the carbonation of magnesium silicate minerals (Power et al., 2009). Field-based studies at Atlin and corroborating laboratory experiments demonstrate the ability of a microbial consortium dominated by filamentous cyanobacteria to induce the precipitation of carbonate minerals. Phototrophic microbes, such as cyanobacteria, have been proposed as a means for producing biodiesel and other value added products because of their efficiency as solar collectors and low requirement for valuable, cultivable land in comparison to crops (Dismukes et al., 2008). Carbonate precipitation and biomass production could be facilitated using specifically designed ponds to collect waters rich in dissolved cations (e.g., Mg2+ and Ca2+), which would allow for evapoconcentration and provide an appropriate environment for growth of cyanobacteria. Microbially mediated carbonate precipitation does not require large quantities of energy or chemicals needed for industrial systems that have been proposed for rapid carbon capture and storage via mineral carbonation (e.g., Lackner et al., 1995). Therefore, this biogeochemical approach may represent a readily

  18. Life Support Systems Microbial Challenges

    NASA Technical Reports Server (NTRS)

    Roman, Monserrate C.

    2009-01-01

    This viewgraph presentation reviews the current microbial challenges of environmental control and life support systems. The contents include: 1) Environmental Control and Life Support Systems (ECLSS) What is it?; 2) A Look Inside the International Space Station (ISS); 3) The Complexity of a Water Recycling System; 4) ISS Microbiology Acceptability Limits; 5) Overview of Current Microbial Challenges; 6) In a Perfect World What we Would like to Have; and 7) The Future.

  19. Microbial genomes: Blueprints for life

    SciTech Connect

    Relman, David A.; Strauss, Evelyn

    2000-12-31

    Complete microbial genome sequences hold the promise of profound new insights into microbial pathogenesis, evolution, diagnostics, and therapeutics. From these insights will come a new foundation for understanding the evolution of single-celled life, as well as the evolution of more complex life forms. This report is an in-depth analysis of scientific issues that provides recommendations and will be widely disseminated to the scientific community, federal agencies, industry and the public.

  20. Biogeochemical Processes in Microbial Ecosystems

    NASA Technical Reports Server (NTRS)

    DesMarais, David J.

    2001-01-01

    The hierarchical organization of microbial ecosystems determines process rates that shape Earth's environment, create the biomarker sedimentary and atmospheric signatures of life, and define the stage upon which major evolutionary events occurred. In order to understand how microorganisms have shaped the global environment of Earth and, potentially, other worlds, we must develop an experimental paradigm that links biogeochemical processes with ever-changing temporal and spatial distributions of microbial populations and their metabolic properties. Additional information is contained in the original extended abstract.

  1. Glass-forming ability of compounds in marketed amorphous drug products.

    PubMed

    Wyttenbach, Nicole; Kuentz, Martin

    2017-03-01

    This note is about the glass-forming ability (GFA) of drugs marketed as amorphous solid dispersions or as pure amorphous compounds. A thermoanalytical method was complemented with an in silico study, which made use of molecular properties that were identified earlier as being relevant for GFA. Thus, molar volume together with effective numbers of torsional bonds and hydrogen bonding were used to map drugs that are as amorphous products on the market either as solid dispersion of without co-processed carrier as amorphous drug in a solid dosage form. Differential scanning calorimetry experiments showed that most compounds were stable glass formers (GFs) (class III) followed by so-called unstable GFs (class II) and finally, only vemurafenib was found in class I with increased crystallization propensity. The in silico results, however showed that all drugs were either clearly in the chemical space expected for GFs or they were borderline to the region that holds for high crystallization tendency. Interestingly, the pure amorphous compounds scattered in a very confined region of the molecular predictors. These findings can guide amorphous product development of future drug candidates. Based on the compound location in the given chemical space, amorphous formulation opportunities can be balanced against the risks of physical instability upon storage.

  2. The eyes of a tiny 'Orsten' crustacean - a compound eye at receptor level?

    PubMed

    Schoenemann, Brigitte

    2013-01-14

    Among the oldest fossil crustaceans are those of the Late Cambrian (Furongian 499 ± 0.3-488.3 ± 1.7 Ma) of Västergötland, central Sweden and the lower Ordovician (Tremadocian 488.3 and 478.6 Ma) of the island of Őland. These are three-dimensionally preserved in nodules from the so called 'stinkstone' ('Orsten') limestone. 'Orsten'-like fossils represent tiny, often meiobenthic organsisms (Haug, Maas, & Waloszek, 2009) smaller than 2mm, which mainly were arthropods, especially crustaceans close to the stemline. As a result of phosphatisation, hairs, bristles and even cellular structures up to 0.3 μm are preserved (Walossek, 1993), especially compound eyes, as typical for all visually orientated crustaceans (Schoenemann et al., 2011). We show a miniscule prototype of a compound eye (∼40 μm) in a small crustacean, which lived almost half a billion years ago. The eye is close to but comfortably established above being limited in its resolving power by diffraction, but it is too small to be an apposition eye, normally regarded as the basal form of all compound eyes, as is found in bees, dragonflies, crustaceans and many other arthropods still living today. The facets of this compound eye are ∼8 μm in size, the surface structure indicates the relicts of a tiny lens covering each facet. In order to work functionally and to ensure that that diffraction and waveguide problems were avoided, it seems reasonable to suppose that the compound eye consisted of visual units, each with a single photoreceptor cell directly below a weak lens for capturing and slightly focusing the light. The entire unit has a diameter similar to that of a normal sensory cell as found in compound eyes. Thus, the early compound eye analysed here may be interpreted as a prototype representing the earliest stages of the evolution of crustacean compound eyes.

  3. Prediction of Competitive Microbial Growth.

    PubMed

    Fujikawa, Hiroshi

    2016-01-01

     Prediction of competitive microbial growth is becoming important for microbial food safety. There would be two approaches to predict competitive microbial growth with mathematical models. The first approach is the development of a growth model for competitive microbes. Among several candidates for the competition model considered, the combination of the primary growth model of the new logistic (NL) model and the competition model of the Lotka-Vorttera (LV) model showed the best performance in predicting microbial competitive growth in the mixed culture of two species. This system further successfully predicted the growth of three competitive species in mixed culture. The second approach is the application of the secondary model especially for the parameter of the maximum cell population in the primary growth model. The combination of the NL model and a polynomial model for the maximum population successfully predicted Salmonella growth in raw ground beef. This system further successfully predicted Salmonella growth in beef at various initial concentrations and temperatures. The first approach requires microbial growth data in monoculture for analysis. The second approach to the prediction of competitive growth from the viewpoint of microbial food safety would be more suitable for practical application.

  4. In-Drift Microbial Communities

    SciTech Connect

    D. Jolley

    2000-11-09

    As directed by written work direction (CRWMS M and O 1999f), Performance Assessment (PA) developed a model for microbial communities in the engineered barrier system (EBS) as documented here. The purpose of this model is to assist Performance Assessment and its Engineered Barrier Performance Section in modeling the geochemical environment within a potential repository drift for TSPA-SR/LA, thus allowing PA to provide a more detailed and complete near-field geochemical model and to answer the key technical issues (KTI) raised in the NRC Issue Resolution Status Report (IRSR) for the Evolution of the Near Field Environment (NFE) Revision 2 (NRC 1999). This model and its predecessor (the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document, CRWMS M and O 1998a) was developed to respond to the applicable KTIs. Additionally, because of the previous development of the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a), the M and O was effectively able to resolve a previous KTI concern regarding the effects of microbial processes on seepage and flow (NRC 1998). This document supercedes the in-drift microbial communities model as documented in Chapter 4 of the TSPA-VA Technical Basis Document (CRWMS M and O 1998a). This document provides the conceptual framework of the revised in-drift microbial communities model to be used in subsequent performance assessment (PA) analyses.

  5. Microbial production of propanol.

    PubMed

    Walther, Thomas; François, Jean Marie

    2016-01-01

    Both, n-propanol and isopropanol are industrially attractive value-added molecules that can be produced by microbes from renewable resources. The development of cost-effective fermentation processes may allow using these alcohols as a biofuel component, or as a precursor for the chemical synthesis of propylene. This review reports and discusses the recent progress which has been made in the biochemical production of propanol. Several synthetic propanol-producing pathways were developed that vary with respect to stoichiometry and metabolic entry point. These pathways were expressed in different host organisms and enabled propanol production from various renewable feedstocks. Furthermore, it was shown that the optimization of fermentation conditions greatly improved process performance, in particular, when continuous product removal prevented accumulation of toxic propanol levels. Although these advanced metabolic engineering and fermentation strategies have facilitated significant progress in the biochemical production of propanol, the currently achieved propanol yields and productivities appear to be insufficient to compete with chemical propanol synthesis. The development of biosynthetic pathways with improved propanol yields, the breeding or identification of microorganisms with higher propanol tolerance, and the engineering of propanol producer strains that efficiently utilize low-cost feedstocks are the major challenges on the way to industrially relevant microbial propanol production processes.

  6. Microbial Production of Biovanillin

    PubMed Central

    Converti, A.; Aliakbarian, B.; Domínguez, J.M.; Bustos Vázquez, G.; Perego, P.

    2010-01-01

    This review aims at providing an overview on the microbial production of vanillin, a new alternative method for the production of this important flavor of the food industry, which has the potential to become economically competitive in the next future. After a brief description of the applications of vanillin in different industrial sectors and of its physicochemical properties, we described the traditional ways of providing vanillin, specifically extraction and chemical synthesis (mainly oxidation) and compared them with the new biotechnological options, i.e., biotransformations of caffeic acid, veratraldehyde and mainly ferulic acid. In the second part of the review, emphasis has been addressed to the factors most influencing the bioproduction of vanillin, specifically the age of inoculum, pH, temperature, type of co-substrate, as well as the inhibitory effects exerted either by excess substrate or product. The final part of the work summarized the downstream processes and the related unit operations involved in the recovery of vanillin from the bioconversion medium. PMID:24031526

  7. Automated Microbial Metabolism Laboratory

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The Automated Microbial Metabolism Laboratory (AMML) 1971-1972 program involved the investigation of three separate life detection schemes. The first was a continued further development of the labeled release experiment. The possibility of chamber reuse without inbetween sterilization, to provide comparative biochemical information was tested. Findings show that individual substrates or concentrations of antimetabolites may be sequentially added to a single test chamber. The second detection system which was investigated for possible inclusion in the AMML package of assays, was nitrogen fixation as detected by acetylene reduction. Thirdly, a series of preliminary steps were taken to investigate the feasibility of detecting biopolymers in soil. A strategy for the safe return to Earth of a Mars sample prior to manned landings on Mars is outlined. The program assumes that the probability of indigenous life on Mars is unity and then broadly presents the procedures for acquisition and analysis of the Mars sample in a manner to satisfy the scientific community and the public that adequate safeguards are being taken.

  8. Chaos and microbial systems

    SciTech Connect

    Kot, M.

    1990-07-01

    A recurrent theme of much recent research is that seemingly random fluctuations often occur as the result of simple deterministic mechanisms. Hence, much of the recent work in nonlinear dynamics has centered on new techniques for identifying order in seemingly chaotic systems. To determine the robustness of these techniques, chaos must, to some extent, be brought into the laboratory. Preliminary investigations of the forced double-Monod equations, a model for a predator and a prey in a chemostat with periodic variation in inflowing substrate concentration, suggest that simple microbial systems may provide the perfect framework for determining the efficacy and relevance of the new nonlinear dynamics in dealing with complex population dynamics. This research has two main goals, that is the mathematical analysis and computer simulation of the periodically forced double-Monod equations and of related models; and experimental (chemostat) population studies that evaluate the accuracy and generality of the models, and that judge the usefulness of various new techniques of nonlinear dynamics to the study of populations.

  9. 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.

  10. Microbial Source Tracking: Current and Future Molecular Tools in Microbial Water Quality Forensics

    EPA Science Inventory

    Current regulations in the United States stipulate that the microbial quality of waters used for consumption and recreational activities should be determined regularly by measuring microbial indicators of fecal pollution. Hence, the microbial risk associated with these waters is...

  11. Effects of Actinomycete Secondary Metabolites on Sediment Microbial Communities.

    PubMed

    Patin, Nastassia V; Schorn, Michelle; Aguinaldo, Kristen; Lincecum, Tommie; Moore, Bradley S; Jensen, Paul R

    2017-02-15

    Marine sediments harbor complex microbial communities that remain poorly studied relative to other biomes such as seawater. Moreover, bacteria in these communities produce antibiotics and other bioactive secondary metabolites, yet little is known about how these compounds affect microbial community structure. In this study, we used next-generation amplicon sequencing to assess native microbial community composition in shallow tropical marine sediments. The results revealed complex communities comprised of largely uncultured taxa, with considerable spatial heterogeneity and known antibiotic producers comprising only a small fraction of the total diversity. Organic extracts from cultured strains of the sediment-dwelling actinomycete genus Salinispora were then used in mesocosm studies to address how secondary metabolites shape sediment community composition. We identified predatory bacteria and other taxa that were consistently reduced in the extract-treated mesocosms, suggesting that they may be the targets of allelopathic interactions. We tested related taxa for extract sensitivity and found general agreement with the culture-independent results. Conversely, several taxa were enriched in the extract-treated mesocosms, suggesting that some bacteria benefited from the interactions. The results provide evidence that bacterial secondary metabolites can have complex and significant effects on sediment microbial communities.

  12. Simulated Carbon Cycling in a Model Microbial Mat.

    NASA Astrophysics Data System (ADS)

    Decker, K. L.; Potter, C. S.

    2006-12-01

    We present here the novel addition of detailed organic carbon cycling to our model of a hypersaline microbial mat ecosystem. This ecosystem model, MBGC (Microbial BioGeoChemistry), simulates carbon fixation through oxygenic and anoxygenic photosynthesis, and the release of C and electrons for microbial heterotrophs via cyanobacterial exudates and also via a pool of dead cells. Previously in MBGC, the organic portion of the carbon cycle was simplified into a black-box rate of accumulation of simple and complex organic compounds based on photosynthesis and mortality rates. We will discuss the novel inclusion of fermentation as a source of carbon and electrons for use in methanogenesis and sulfate reduction, and the influence of photorespiration on labile carbon exudation rates in cyanobacteria. We will also discuss the modeling of decomposition of dead cells and the ultimate release of inorganic carbon. The detailed modeling of organic carbon cycling is important to the accurate representation of inorganic carbon flux through the mat, as well as to accurate representation of growth models of the heterotrophs under different environmental conditions. Because the model ecosystem is an analog of ancient microbial mats that had huge impacts on the atmosphere of early earth, this MBGC can be useful as a biological component to either early earth models or models of other planets that potentially harbor life.

  13. Electron beam irradiation of Matricaria chamomilla L. for microbial decontamination

    NASA Astrophysics Data System (ADS)

    Nemţanu, Monica R.; Kikuchi, Irene Satiko; de Jesus Andreoli Pinto, Terezinha; Mazilu, Elena; Setnic, Silvia; Bucur, Marcela; Duliu, Octavian G.; Meltzer, Viorica; Pincu, Elena

    2008-05-01

    Wild chamomile (Matricaria chamomilla L.) is one of the most popular herbal materials with both internal and external use to cure different health disturbances. As a consequence of its origin, chamomile could carry various microbial contaminants which offer different hazards to the final consumer. Reduction of the microbial load to the in force regulation limits represents an important phase in the technological process of vegetal materials, and the electron beam treatment might be an efficient alternative to the classical methods of hygienic quality assurance. The purpose of the study was to analyze the potential application of the electron beam treatment in order to assure the microbial safety of the wild chamomile. Samples of chamomile dry inflorescences were treated in electron beam (e-beam) of 6 MeV mean energy, at room temperature and ambient pressure. Some loss of the chemical compounds with bioactive role could be noticed, but the number of microorganisms decreased as a function on the absorbed dose. Consequently, the microbial quality of studied vegetal material inflorescences was improved by e-beam irradiation.

  14. Microbial Communities of Continuously Cropped, Irrigated Rice Fields

    PubMed Central

    Reichardt, W.; Mascarina, G.; Padre, B.; Doll, J.

    1997-01-01

    In continuously cropped, irrigated rice fields, soil microbial biomass as measured by total phospholipid fatty acid concentrations declined during the second half of the crop cycle. This decline was also observed in other components of the microbial community assessed by viable counts, including denitrifiers and sporeformers. Simultaneous with total biomass decline was the increase in potential indicators of nutrient stress--such as ratios of cyclopropanol ((Sigma)[cy/(omega)7c]) and trans ((Sigma)[(omega)7t/(omega)7c]) phospholipid fatty acids--in plain crop soil but not in the rhizosphere. Polyhydroxyalkanoate levels were enhanced in the root environment of mature rice. Polyunsaturated eukaryotic biomarkers accounted for only 13 to 16 mol% of the total phospholipids, including 2 mol% of 18:2(omega)6, which is considered a fungal biomarker. Single biomarkers for defined physiological groups of bacteria did not follow the declining trend of total microbial biomass. Signature compounds for gram-positive and gram-negative fermenters (plasmalogen phospholipids), methanogenic bacteria (diether lipids), and methanotrophs (18:1(omega)8c) increased as the crop approached maturity. Methanotrophs were not particularly enriched in the rhizosphere. Methanogenic biomarkers were, however, most abundant in root extracts from mature rice plants. Assuming that soil microbial biomass plays a significant role as a passive nutrient pool, its reduction during the second half of the cropping season suggests a mechanism that may ultimately contribute to declining productivity in irrigated, continuous rice cropping systems. PMID:16535489

  15. Fractionating soluble microbial products in the activated sludge process.

    PubMed

    Ni, Bing-Jie; Zeng, Raymond J; Fang, Fang; Xie, Wen-Ming; Sheng, Guo-Ping; Yu, Han-Qing

    2010-04-01

    Soluble microbial products (SMP) are the pool of organic compounds originating from microbial growth and decay, and are usually the major component of the soluble organic matters in effluents from biological treatment processes. In this work, SMP in activated sludge were characterized, fractionized, and quantified using integrated chemical analysis and mathematical approach. The utilization-associated products (UAP) in SMP, produced in the substrate-utilization process, were found to be carbonaceous compounds with a molecular weight (MW) lower than 290 kDa which were quantified separately from biomass-associated products (BAP). The BAP were mainly cellular macromolecules with an MW in a range of 290-5000 kDa, and for the first time were further classified into the growth-associated BAP (GBAP) with an MW of 1000 kDa, which were produced in the microbial growth phase, and the endogeny-associated BAP (EBAP) with an MW of 4500 kDa, which were generated in the endogenous phase. Experimental and modeling results reveal that the UAP could be utilized by the activated sludge and that the BAP would accumulate in the system. The GBAP and EBAP had different formation rates from the hydrolysis of extracellular polymeric substances and distinct biodegradation kinetics. This study provides better understanding of SMP formation mechanisms and becomes useful for subsequent effluent treatment.

  16. 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.

  17. High-Up: A Remote Reservoir of Microbial Extremophiles in Central Andean Wetlands

    PubMed Central

    Albarracín, Virginia H.; Kurth, Daniel; Ordoñez, Omar F.; Belfiore, Carolina; Luccini, Eduardo; Salum, Graciela M.; Piacentini, Ruben D.; Farías, María E.

    2015-01-01

    The Central Andes region displays unexplored ecosystems of shallow lakes and salt flats at mean altitudes of 3700 m. Being isolated and hostile, these so-called “High-Altitude Andean Lakes” (HAAL) are pristine and have been exposed to little human influence. HAAL proved to be a rich source of microbes showing interesting adaptations to life in extreme settings (poly-extremophiles) such as alkalinity, high concentrations of arsenic and dissolved salts, intense dryness, large daily ambient thermal amplitude, and extreme solar radiation levels. This work reviews HAAL microbiodiversity, taking into account different microbial niches, such as plankton, benthos, microbial mats and microbialites. The modern stromatolites and other microbialites discovered recently at HAAL are highlighted, as they provide unique modern—though quite imperfect—analogs of environments proxy for an earlier time in Earth's history (volcanic setting and profuse hydrothermal activity, low atmospheric O2 pressure, thin ozone layer and high UV exposure). Likewise, we stress the importance of HAAL microbes as model poly-extremophiles in the study of the molecular mechanisms underlying their resistance ability against UV and toxic or deleterious chemicals using genome mining and functional genomics. In future research directions, it will be necessary to exploit the full potential of HAAL poly-extremophiles in terms of their biotechnological applications. Current projects heading this way have yielded detailed molecular information and functional proof on novel extremoenzymes: i.e., DNA repair enzymes and arsenic efflux pumps for which medical and bioremediation applications, respectively, are envisaged. But still, much effort is required to unravel novel functions for this and other molecules that dwell in a unique biological treasure despite its being hidden high up, in the remote Andes. PMID:26733008

  18. High-Up: A Remote Reservoir of Microbial Extremophiles in Central Andean Wetlands.

    PubMed

    Albarracín, Virginia H; Kurth, Daniel; Ordoñez, Omar F; Belfiore, Carolina; Luccini, Eduardo; Salum, Graciela M; Piacentini, Ruben D; Farías, María E

    2015-01-01

    The Central Andes region displays unexplored ecosystems of shallow lakes and salt flats at mean altitudes of 3700 m. Being isolated and hostile, these so-called "High-Altitude Andean Lakes" (HAAL) are pristine and have been exposed to little human influence. HAAL proved to be a rich source of microbes showing interesting adaptations to life in extreme settings (poly-extremophiles) such as alkalinity, high concentrations of arsenic and dissolved salts, intense dryness, large daily ambient thermal amplitude, and extreme solar radiation levels. This work reviews HAAL microbiodiversity, taking into account different microbial niches, such as plankton, benthos, microbial mats and microbialites. The modern stromatolites and other microbialites discovered recently at HAAL are highlighted, as they provide unique modern-though quite imperfect-analogs of environments proxy for an earlier time in Earth's history (volcanic setting and profuse hydrothermal activity, low atmospheric O2 pressure, thin ozone layer and high UV exposure). Likewise, we stress the importance of HAAL microbes as model poly-extremophiles in the study of the molecular mechanisms underlying their resistance ability against UV and toxic or deleterious chemicals using genome mining and functional genomics. In future research directions, it will be necessary to exploit the full potential of HAAL poly-extremophiles in terms of their biotechnological applications. Current projects heading this way have yielded detailed molecular information and functional proof on novel extremoenzymes: i.e., DNA repair enzymes and arsenic efflux pumps for which medical and bioremediation applications, respectively, are envisaged. But still, much effort is required to unravel novel functions for this and other molecules that dwell in a unique biological treasure despite its being hidden high up, in the remote Andes.

  19. Diethyl phthalate in compost: ecotoxicological effects and response of the microbial community.

    PubMed

    Kapanen, A; Stephen, J R; Brüggemann, J; Kiviranta, A; White, D C; Itävaara, M

    2007-05-01

    There is a great need to understand the environmental impacts of organic pollutants on soil health. Phthalates are widely used in consumables and can be found extensively. We studied the toxicity of diethyl phthalate (DEP), spiked in a compost plant growth substrate, by means of the acute toxicity Flash test and on the basis of the germination and plant growth of radish seedlings. The response of the microbial community to DEP in the growth substrate was studied by PCR-DGGE (denaturing gradient gel electrophoresis). In the acute toxicity test, DEP was found to be less toxic as a pure compound than when mixed with the compost mixture. This suggests the synergistic effect of unknown toxic compounds or the release of compounds due to DEP addition. The same DEP concentration level in compost substrate induced toxic response in both plant test and microbial community analysis. The diversity of the major microbial community was reduced from a broad community to only 10 major species at toxic concentrations of DEP. Several of the identified microbial species are known to be able to degrade phthalates, which means that the suppression of other microbial species might be due to the substrate availability and toxicity. The major species identified included Sphingomonas sp., Pseudomonas sp., Actinomycetes sp.

  20. Continuous power generation and microbial community structure of the anode biofilms in a three-stage microbial fuel cell system.

    PubMed

    Chung, Kyungmi; Okabe, Satoshi

    2009-07-01

    A mediator-less three-stage two-chamber microbial fuel cell (MFC) system was developed and operated continuously for more than 1.5 years to evaluate continuous power generation while treating artificial wastewater containing glucose (10 mM) concurrently. A stable power density of 28 W/m(3) was attained with an anode hydraulic retention time of 4.5 h and phosphate buffer as the cathode electrolyte. An overall dissolved organic carbon removal ratio was about 85%, and coulombic efficiency was about 46% in this MFC system. We also analyzed the microbial community structure of anode biofilms in each MFC. Since the environment in each MFC was different due to passing on the products to the next MFC in series, the microbial community structure was different accordingly. The anode biofilm in the first MFC consisted mainly of bacteria belonging to the Gammaproteobacteria, identified as Aeromonas sp., while the Firmicutes dominated the anode biofilms in the second and third MFCs that were mainly fed with acetate. Cyclic voltammetric results supported the presence of a redox compound(s) associated with the anode biofilm matrix, rather than mobile (dissolved) forms, which could be responsible for the electron transfer to the anode. Scanning electron microscopy revealed that the anode biofilms were comprised of morphologically different cells that were firmly attached on the anode surface and interconnected each other with anchor-like filamentous appendages, which might support the results of cyclic voltammetry.

  1. Degradation potential and microbial community structure of heavy oil-enriched microbial consortia from mangrove sediments in Okinawa, Japan.

    PubMed

    Bacosa, Hernando P; Suto, Koichi; Inoue, Chihiro

    2013-01-01

    Mangroves constitute valuable coastal resources that are vulnerable to oil pollution. One of the major processes to remove oil from contaminated mangrove sediment is microbial degradation. A study on heavy oil- and hydrocarbon-degrading bacterial consortia from mangrove sediments in Okinawa, Japan was performed to evaluate their capacity to biodegrade and their microbial community composition. Surface sediment samples were obtained from mangrove sites in Okinawa (Teima, Oura, and Okukubi) and enriched with heavy oil as the sole carbon and energy source. The results revealed that all enriched microbial consortia degraded more than 20% of heavy oil in 21 days. The K1 consortium from Okukubi site showed the most extensive degradative capacity after 7 and 21 days. All consortia degraded more than 50% of hexadecane but had little ability to degrade polycyclic aromatic hydrocarbons (PAHs). The consortia were dominated by Pseudomonas or Burkholderia. When incubated in the presence of hydrocarbon compounds, the active bacterial community shifted to favor the dominance of Pseudomonas. The K1 consortium was a superior degrader, demonstrating the highest ability to degrade aliphatic and aromatic hydrocarbon compounds; it was even able to degrade heavy oil at a concentration of 15%(w/v). The dominance and turn-over of Pseudomonas and Burkholderia in the consortia suggest an important ecological role for and relationship between these two genera in the mangrove sediments of Okinawa.

  2. [Microbial geochemical calcium cycle].

    PubMed

    Zavarzin, G A

    2002-01-01

    The participation of microorganisms in the geochemical calcium cycle is the most important factor maintaining neutral conditions on the Earth. This cycle has profound influence on the fate of inorganic carbon, and, thereby, on the removal of CO2 from the atmosphere. The major part of calcium deposits was formed in the Precambrian, when prokaryotic biosphere predominated. After that, calcium recycling based on biogenic deposition by skeletal organisms became the main process. Among prokaryotes, only a few representatives, e.g., cyanobacteria, exhibit a special calcium function. The geochemical calcium cycle is made possible by the universal features of bacteria involved in biologically mediated reactions and is determined by the activities of microbial communities. In the prokaryotic system, the calcium cycle begins with the leaching of igneous rock predominantly through the action of the community of organotrophic organisms. The release of carbon dioxide to the soil air by organotrophic aerobes leads to leaching with carbonic acid and soda salinization. Under anoxic conditions, of major importance is the organic acid production by primary anaerobes (fermentative microorganisms). Calcium carbonate is precipitated by secondary anaerobes (sulfate reducers) and to a smaller degree by methanogens. The role of the cyanobacterial community in carbonate deposition is exposed by stromatolites, which are the most common organo-sedimentary Precambrian structures. Deposition of carbonates in cyanobacterial mats as a consequence of photoassimilation of CO2 does not appear to be a significant process. It is argued that carbonates were deposited at the boundary between the "soda continent", which emerged as a result of subaerial leaching with carbonic acid, and the ocean containing Ca2+. Such ecotones provided favorable conditions for the development of the benthic cyanobacterial community, which was a precursor of stromatolites.

  3. Microbial Production of Isoprene

    SciTech Connect

    Ray Fall

    2007-07-29

    Isoprene is a volatile hydrocarbon of unknown function, produced by certain bacteria, plants and animals, sometimes in huge amounts—the Earth’s forests are estimated to emit >500 x 106 tons of isoprene per year. With funding from this program we explored the biochemistry and regulation of isoprene formation in the model bacterial system, Bacillus subtilis, with the goals of explaining the biological rationale for isoprene biogenesis and constructing an isoprene-overproducing microbial system. Although the role for isoprene formation in B. subtilis is still uncertain, our current model for regulation of this hydrocarbon’s synthesis is that isoprene production in B. subtilis is controlled by a combination of i) rapid regulation of isoprene synthase activity and ii) supply of the substrate for isoprene synthase, dimethyallyl diphosphate (DMAPP). This model parallels our current thinking about the control of isoprene formation in plant chloroplasts. In this reporting period we have been working to test part ii) of this model; this work has produced new results using genetic and analytical approaches. For examples, we have developed an analytical method to resolve DMAPP and its isomer, isopentenyl diphosphate, from each other in bacteria and plants. We have also shown that the IPP isomerase (type 2) of B. subtilis is not the source of “isoprene synthase” activity, and discovered that B. subtilis releases C5 isoprenoid alcohols to the medium, suggesting that isoprene plus other C5 isoprenoids may be common by-products of metabolism. In addition, we have continued to work on our discovery that wild type B. subtilis strains form prolific biofilms, are normal components of plant root microflora, and are testing the idea that B. subtilis growing in biofilms uses isoprene to induce plant root exudation.

  4. Chemical diversity of microbial volatiles and their potential for plant growth and productivity.

    PubMed

    Kanchiswamy, Chidananda Nagamangala; Malnoy, Mickael; Maffei, Massimo E

    2015-01-01

    Microbial volatile organic compounds (MVOCs) are produced by a wide array of microorganisms ranging from bacteria to fungi. A growing body of evidence indicates that MVOCs are ecofriendly and can be exploited as a cost-effective sustainable strategy for use in agricultural practice as agents that enhance plant growth, productivity, and disease resistance. As naturally occurring chemicals, MVOCs have potential as possible alternatives to harmful pesticides, fungicides, and bactericides as well as genetic modification. Recent studies performed under open field conditions demonstrate that efficiently adopting MVOCs may contribute to sustainable crop protection and production. We review here the chemical diversity of MVOCs by describing microbial-plants and microbial-microbial interactions. Furthermore, we discuss MVOCs role in inducing phenotypic plant responses and their potential physiological effects on crops. Finally, we analyze potential and actual limitations for MVOC use and deployment in field conditions as a sustainable strategy for improving productivity and reducing pesticide use.

  5. Enhanced turnover of organic matter fractions by microbial stimulation during lignocellulosic waste composting.

    PubMed

    Jurado, M M; Suárez-Estrella, F; López, M J; Vargas-García, M C; López-González, J A; Moreno, J

    2015-06-01

    Enhanced organic matter turnover was detected in lignocellulosic composting piles inoculated with microorganisms specifically capable of decomposing polymeric compounds. In comparison to uninoculated piles, the following results were obtained in the inoculated piles: degradation of hemicellulose, cellulose and lignin were 28%, 21% and 25% respectively higher. Total organic matter, total sugars and phenolic compounds also decreased more intensely. Greater amounts of soluble organic carbon, reducing sugars and soluble proteins were available to the composting microbiota. Recycling of organic to inorganic nitrogen was improved and humification was more intense and earlier attained. Microbial community structure was also affected by inoculation. It was initially thought that these effects were due to enzymatic capabilities of inoculants, however, microbial counts, especially those corresponding to functional groups, revealed that inoculation induced a true stimulation of microbial growth and activity in the entire composting microbiota which was actually responsible for all the beneficial effects reported here.

  6. Performance assessment of a submerged membrane bioreactor using a novel microbial consortium.

    PubMed

    Chon, Kangmin; Lee, Kyungpyo; Kim, In-Soo; Jang, Am

    2016-06-01

    The performance of a submerged membrane bioreactor (MBR) with and without a novel microbial consortium (NMBR vs. CMBR) was compared to provide deeper insights into the effects of changes in water quality and dissolved organic matter (DOM) characteristics by a novel microbial consortium on the fouling characteristics of MBR processes. Despite similar operating conditions and identical DOM properties in the feed waters, NMBR exhibited a lower propensity to release polysaccharide-like compounds with low molecular weight by bacterial activities compared to CMBR. These compounds have a great fouling potential for MBR processes. Therefore, an increase in the transmembrane pressure (TMP) of NMBR (normalized TMP (TMP/TMP0): 1.14) was much slower and less significant than that observed in CMBR (TMP/TMP0: 2.61). These observations imply that the novel microbial consortium can efficiently mitigate membrane fouling by hydrophilic DOM in MBR processes.

  7. Bioremediation of PAHs and VOCs: Advances in clay mineral-microbial interaction.

    PubMed

    Biswas, Bhabananda; Sarkar, Binoy; Rusmin, Ruhaida; Naidu, Ravi

    2015-12-01

    Bioremediation is an effective strategy for cleaning up organic contaminants, such as polycyclic aromatic hydrocarbons (PAHs) and volatile organic compounds (VOCs). Advanced bioremediation implies that biotic agents are more efficient in degrading the contaminants completely. Bioremediation by microbial degradation is often employed and to make this process efficient, natural and cost-effective materials can serve as supportive matrices. Clay/modified clay minerals are effective adsorbents of PAHs/VOCs, and readily available substrate and habitat for microorganisms in the natural soil and sediment. However, the mechanism underpinning clay-mediated biodegradation of organic compounds is often unclear, and this requires critical investigation. This review describes the role of clay/modified clay minerals in hydrocarbon bioremediation through interaction with microbial agents in specific scenarios. The vision is on a faster, more efficient and cost-effective bioremediation technique using clay-based products. This review also proposes future research directions in the field of clay modulated microbial degradation of hydrocarbons.

  8. Perspective for Aquaponic Systems: “Omic” Technologies for Microbial Community Analysis

    PubMed Central

    Munguia-Fragozo, Perla; Alatorre-Jacome, Oscar; Rico-Garcia, Enrique; Torres-Pacheco, Irineo; Cruz-Hernandez, Andres; Ocampo-Velazquez, Rosalia V.; Garcia-Trejo, Juan F.; Guevara-Gonzalez, Ramon G.

    2015-01-01

    Aquaponics is the combined production of aquaculture and hydroponics, connected by a water recirculation system. In this productive system, the microbial community is responsible for carrying out the nutrient dynamics between the components. The nutrimental transformations mainly consist in the transformation of chemical species from toxic compounds into available nutrients. In this particular field, the microbial research, the “Omic” technologies will allow a broader scope of studies about a current microbial profile inside aquaponics community, even in those species that currently are unculturable. This approach can also be useful to understand complex interactions of living components in the system. Until now, the analog studies were made to set up the microbial characterization on recirculation aquaculture systems (RAS). However, microbial community composition of aquaponics is still unknown. “Omic” technologies like metagenomic can help to reveal taxonomic diversity. The perspectives are also to begin the first attempts to sketch the functional diversity inside aquaponic systems and its ecological relationships. The knowledge of the emergent properties inside the microbial community, as well as the understanding of the biosynthesis pathways, can derive in future biotechnological applications. Thus, the aim of this review is to show potential applications of current “Omic” tools to characterize the microbial community in aquaponic systems. PMID:26509157

  9. Carbon input increases microbial nitrogen demand, but not microbial nitrogen mining in boreal forest soils

    NASA Astrophysics Data System (ADS)

    Wild, Birgit; Alaei, Saeed; Bengtson, Per; Bodé, Samuel; Boeckx, Pascal; Schnecker, Jörg; Mayerhofer, Werner; Rütting, Tobias

    2016-04-01

    Plant primary production at mid and high latitudes is often limited by low soil N availability. It has been hypothesized that plants can indirectly increase soil N availability via root exudation, i.e., via the release of easily degradable organic compounds such as sugars into the soil. These compounds can stimulate microbial activity and extracellular enzyme synthesis, and thus promote soil organic matter (SOM) decomposition ("priming effect"). Even more, increased C availability in the rhizosphere might specifically stimulate the synthesis of enzymes targeting N-rich polymers such as proteins that store most of the soil N, but are too large for immediate uptake ("N mining"). This effect might be particularly important in boreal forests, where plants often maintain high primary production in spite of low soil N availability. We here tested the hypothesis that increased C availability promotes protein depolymerization, and thus soil N availability. In a laboratory incubation experiment, we added 13C-labeled glucose to a range of soil samples derived from boreal forests across Sweden, and monitored the release of CO2 by C mineralization, distinguishing between CO2 from the added glucose and from the native, unlabeled soil organic C (SOC). Using a set of 15N pool dilution assays, we further measured gross rates of protein depolymerization (the breakdown of proteins into amino acids) and N mineralization (the microbial release of excess N as ammonium). Comparing unamended control samples, we found a high variability in C and N mineralization rates, even when normalized by SOC content. Both C and N mineralization were significantly correlated to SOM C/N ratios, with high C mineralization at high C/N and high N mineralization at low C/N, suggesting that microorganisms adjusted C and N mineralization rates to the C/N ratio of their substrate and released C or N that was in excess. The addition of glucose significantly stimulated the mineralization of native SOC in soils

  10. Microbial ecology summer research program, June 20-August 26, 1983

    SciTech Connect

    Not Available

    1983-01-01

    The personnel, lecture topics, and summaries of research reports generated are presented. Research topics include: mutants of Escherichia coli affected in inducer exclusion; anaerobic chitin degradation; feeding relationships of harpacticoid copepods and microbial flora; degradation of ortho phenyl phenol by streptomycetes; biodegradation of dieldrin and aromatic compounds; the effect of neurotoxins on chemotaxis is Spirochaeta aurantia; chemotaxis and algal attachment of caulobacter; pigment formation in Lyngbya aestuari; diel movements of bacteria in a salt marsh; chemotaxis in S. Aurantia; isolation of marine toluate-oxidizing bacteria; growth inhibition of enteric bacteria by methyl-..cap alpha..-D-glucoside; studies of magnetic bacteria in brackish waters; and mechanisms of interaction between two microbial populations in activated sludge. (ACR)

  11. Metabolic engineering of microbial competitive advantage for industrial fermentation processes.

    PubMed

    Shaw, A Joe; Lam, Felix H; Hamilton, Maureen; Consiglio, Andrew; MacEwen, Kyle; Brevnova, Elena E; Greenhagen, Emily; LaTouf, W Greg; South, Colin R; van Dijken, Hans; Stephanopoulos, Gregory

    2016-08-05

    Microbial contamination is an obstacle to widespread production of advanced biofuels and chemicals. Current practices such as process sterilization or antibiotic dosage carry excess costs or encourage the development of antibiotic resistance. We engineered Escherichia coli to assimilate melamine, a xenobiotic compound containing nitrogen. After adaptive laboratory evolution to improve pathway efficiency, the engineered strain rapidly outcompeted a control strain when melamine was supplied as the nitrogen source. We additionally engineered the yeasts Saccharomyces cerevisiae and Yarrowia lipolytica to assimilate nitrogen from cyanamide and phosphorus from potassium phosphite, and they outcompeted contaminating strains in several low-cost feedstocks. Supplying essential growth nutrients through xenobiotic or ecologically rare chemicals provides microbial competitive advantage with minimal external risks, given that engineered biocatalysts only have improved fitness within the customized fermentation environment.

  12. 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.

  13. Exploring the metabolic potential of microbial communities in ultra-basic, reducing springs at The Cedars, CA, USA: Experimental evidence of microbial methanogenesis and heterotrophic acetogenesis

    NASA Astrophysics Data System (ADS)

    Kohl, Lukas; Cumming, Emily; Cox, Alison; Rietze, Amanda; Morrissey, Liam; Lang, Susan Q.; Richter, Andreas; Suzuki, Shino; Nealson, Kenneth H.; Morrill, Penny L.

    2016-04-01

    Present-day serpentinization generates groundwaters with conditions (pH > 11, Eh < -550 mV) favorable for the microbial and abiotic production of organic compounds from inorganic precursors. Elevated concentrations of methane, C2-C6 alkanes, acetate, and formate have been detected at these sites, but the microbial or abiotic origin of these compounds remains unclear. While geochemical data indicate that methane at most sites of present-day serpentinization is abiogenic, the stable carbon, hydrogen, and clumped isotope data as well as the hydrocarbon gas composition from The Cedars, CA, USA, are consistent with a microbial origin for methane. However, there is no direct evidence of methanogenesis at this site of serpentinization. We report on laboratory experiments in which the microbial communities in fluids and sediments from The Cedars were incubated with 13C labeled substrates. Increasing methane concentrations and the incorporation of 13C into methane in live experiments, but not in killed controls, demonstrated that methanogens converted methanol, formate, acetate (methyl group), and bicarbonate to methane. The apparent fractionation between methane and potential substrates (α13CCH4-CO2(g) = 1.059 to 1.105, α13CCH4-acetate = 1.042 to 1.119) indicated that methanogenesis was dominated by the carbonate reduction pathway. Increasing concentrations of volatile organic acid anions indicated microbial acetogenesis. α13CCO2(g)-acetate values (0.999 to 1.000), however, were inconsistent with autotrophic acetogenesis, thus suggesting that acetate was produced through fermentation. This is the first study to show direct evidence of microbial methanogenesis and acetogenesis by the native microbial community at a site of present-day serpentinization.

  14. XAFS Model Compound Library

    DOE Data Explorer

    Newville, Matthew

    The XAFS Model Compound Library contains XAFS data on model compounds. The term "model" compounds refers to compounds of homogeneous and well-known crystallographic or molecular structure. Each data file in this library has an associated atoms.inp file that can be converted to a feff.inp file using the program ATOMS. (See the related Searchable Atoms.inp Archive at http://cars9.uchicago.edu/~newville/adb/) This Library exists because XAFS data on model compounds is useful for several reasons, including comparing to unknown data for "fingerprinting" and testing calculations and analysis methods. The collection here is currently limited, but is growing. The focus to date has been on inorganic compounds and minerals of interest to the geochemical community. [Copied, with editing, from http://cars9.uchicago.edu/~newville/ModelLib/

  15. Modeling microbial growth and dynamics.

    PubMed

    Esser, Daniel S; Leveau, Johan H J; Meyer, Katrin M

    2015-11-01

    Modeling has become an important tool for widening our understanding of microbial growth in the context of applied microbiology and related to such processes as safe food production, wastewater treatment, bioremediation, or microbe-mediated mining. Various modeling techniques, such as primary, secondary and tertiary mathematical models, phenomenological models, mechanistic or kinetic models, reactive transport models, Bayesian network models, artificial neural networks, as well as agent-, individual-, and particle-based models have been applied to model microbial growth and activity in many applied fields. In this mini-review, we summarize the basic concepts of these models using examples and applications from food safety and wastewater treatment systems. We further review recent developments in other applied fields focusing on models that explicitly include spatial relationships. Using these examples, we point out the conceptual similarities across fields of application and encourage the combined use of different modeling techniques in hybrid models as well as their cross-disciplinary exchange. For instance, pattern-oriented modeling has its origin in ecology but may be employed to parameterize microbial growth models when experimental data are scarce. Models could also be used as virtual laboratories to optimize experimental design analogous to the virtual ecologist approach. Future microbial growth models will likely become more complex to benefit from the rich toolbox that is now available to microbial growth modelers.

  16. Carbon Turnover and Dynamics from Biochemically Diverse Microbial Groups in Temperate and Tropical Forest Soils

    NASA Astrophysics Data System (ADS)

    Throckmorton, H.; Bird, J. A.; Firestone, M.; Horwath, W. R.

    2009-12-01

    microbial C turnover associated with different compound classes including polysaccharide, protein, and lipid. Ongoing work examines the turnover of specific compound classes associated with the input microbial C in soil physical fractions.

  17. Chlorpromazine as permeabilizer and reagent for detection of microbial peroxidase and peroxidaselike activities.

    PubMed Central

    Galeazzi, L; Turchetti, G; Grilli, G; Groppa, G; Giunta, S

    1986-01-01

    Chlorpromazine was used to perform a test for the detection of microbial peroxidase activities. The compound acts as both a cell permeabilizer and a reagent in the procedure developed which allows the detection of peroxidase and peroxidase like reactions both semiquantitatively in whole cell determinations and quantitatively in cell-free supernatants. PMID:3539020

  18. Analyses of microbial populations and antibiotic resistance present in stored swine manure from underground storage pits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antimicrobial compounds have been commonly used as feed additives for domestic animals to reduce infection and promote growth. Recent concerns have suggested such feeding practices may result in increased microbial resistance to antibiotics, which can have an impact on human health. While many inves...

  19. Microbial Interactions Associated with Biofilms Attached to Trichodesmium spp. and Detrital Particles in the Ocean

    DTIC Science & Technology

    2010-06-01

    Trichodesmium spp. and detrital ( photosynthetically -derived sinking particulate organic carbon, POC) particles. These hot spots of microbial activity...compounds toxic to algae (e.g. prodigiosin, Nakashima et al., 2006), two processes which may directly impact the fate of photosynthetically derived...within biofilms attached to the bloom forming cyanobacterium, Trichodesmium, as well as photosynthetically -derived, detrital sinking-particulate organic

  20. Microbial hydroxylation of o-bromophenylacetic acid: synthesis of 4-substituted-2,3-dihydrobenzofurans.

    PubMed

    Deshpande, Prashant P; Nanduri, Venkata B; Pullockaran, Annie; Christie, Hamish; Mueller, Richard H; Patel, Ramesh N

    2008-08-01

    Microbial hydroxylation of o-bromophenylacetic acid provided 2-bromo-5-hydroxyphenylacetic acid. This enabled a route to the key intermediate 4-bromo-2,3-dihydrobenzofuran for synthesizing a melatonin receptor agonist and sodium hydrogen exchange compounds. Pd-mediated coupling reactions of 4-bromo-2,3-dihydrobenzofuran provided easy access to the 4-substituted-2,3-dihydrobenzofurans.