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Sample records for microbial janitors tackle

  1. The School Janitor: A Study of the Functions and Administration of School Janitor Service. Bulletin, 1922, No. 24

    ERIC Educational Resources Information Center

    Garber, John Absalom

    1922-01-01

    There are three reasons why the following study of the school janitor service has been made: (1) The importance of the janitor's position in a modern school system. This is seen by a consideration, especially, of his relation to the up-keep and sanitation of buildings in his charge, the health and safety of their occupants, the educative value of…

  2. Even the Janitor Is White: Educating for Cultural Diversity in Small Colleges and Universities. Critical Education and Ethics. Volume 4

    ERIC Educational Resources Information Center

    Hickey, M. Gail, Ed.; Lanahan, Brian K., Ed.

    2012-01-01

    "Even the Janitor Is White" addresses challenges faced by teacher educators who are committed to diversity education. The chapters in this volume invite readers to reflect on their own practice as teacher educators as well as consider ways in which that practice might be improved. More than forty percent of students in U.S. schools are…

  3. Tackling in Youth Football.

    PubMed

    2015-11-01

    American football remains one of the most popular sports for young athletes. The injuries sustained during football, especially those to the head and neck, have been a topic of intense interest recently in both the public media and medical literature. The recognition of these injuries and the potential for long-term sequelae have led some physicians to call for a reduction in the number of contact practices, a postponement of tackling until a certain age, and even a ban on high school football. This statement reviews the literature regarding injuries in football, particularly those of the head and neck, the relationship between tackling and football-related injuries, and the potential effects of limiting or delaying tackling on injury risk.

  4. 46 CFR 184.300 - Ground tackle and mooring lines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Ground tackle and mooring lines. 184.300 Section 184.300... Ground tackle and mooring lines. A vessel must be fitted with ground tackle and mooring lines necessary for the vessel to be safely anchored or moored. The ground tackle and mooring lines provided must...

  5. 46 CFR 184.300 - Ground tackle and mooring lines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Ground tackle and mooring lines. 184.300 Section 184.300... Ground tackle and mooring lines. A vessel must be fitted with ground tackle and mooring lines necessary for the vessel to be safely anchored or moored. The ground tackle and mooring lines provided must...

  6. 46 CFR 184.300 - Ground tackle and mooring lines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Ground tackle and mooring lines. 184.300 Section 184.300... Ground tackle and mooring lines. A vessel must be fitted with ground tackle and mooring lines necessary for the vessel to be safely anchored or moored. The ground tackle and mooring lines provided must...

  7. 46 CFR 184.300 - Ground tackle and mooring lines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Ground tackle and mooring lines. 184.300 Section 184.300... Ground tackle and mooring lines. A vessel must be fitted with ground tackle and mooring lines necessary for the vessel to be safely anchored or moored. The ground tackle and mooring lines provided must...

  8. Baltimore District Tackles High Suspension Rates

    ERIC Educational Resources Information Center

    Maxwell, Lesli A.

    2007-01-01

    This article reports on how the Baltimore District tackles its high suspension rates. Driven by an increasing belief that zero-tolerance disciplinary policies are ineffective, more educators are embracing strategies that do not exclude misbehaving students from school for offenses such as insubordination, disrespect, cutting class, tardiness, and…

  9. Tackling Noncommunicable Diseases in Africa: Caveat Lector

    ERIC Educational Resources Information Center

    Mensah, George A.

    2016-01-01

    Noncommunicable disease (NCD), principally cardiovascular diseases, cancer, chronic lung disease, and diabetes, constitutes the major cause of death worldwide. Evidence of a continuing increase in the global burden of these diseases has generated recent urgent calls for global action to tackle and reduce related death and disability. Because the…

  10. Tackling Noncommunicable Diseases in Africa: Caveat Lector.

    PubMed

    Mensah, George A

    2016-04-01

    Noncommunicable disease (NCD), principally cardiovascular diseases, cancer, chronic lung disease, and diabetes, constitutes the major cause of death worldwide. Evidence of a continuing increase in the global burden of these diseases has generated recent urgent calls for global action to tackle and reduce related death and disability. Because the majority of NCD deaths occur in low- and middle-income countries, increased attention has been focused on this group of countries. However, in sub-Saharan Africa, where all countries are members of the low- and middle-income grouping, NCDs are not the leading causes of death or potential life years lost. Thus, strategies to tackle NCDs in sub-Saharan Africa are best conceived and executed in alignment with existing strategies for the prevention, treatment, and control of the actual leading causes of death in this region. This commentary addresses caveats to be considered as strategies are developed to tackle NCDs in sub-Saharan Africa as part of the global effort to prevent, treat, and control NCDs.

  11. 46 CFR 121.300 - Ground tackle and mooring lines.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Ground tackle and mooring lines. 121.300 Section 121.300... MISCELLANEOUS SYSTEMS AND EQUIPMENT Mooring and Towing Equipment § 121.300 Ground tackle and mooring lines. A vessel must be fitted with ground tackle and mooring lines necessary for the vessel to be safely...

  12. 46 CFR 121.300 - Ground tackle and mooring lines.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Ground tackle and mooring lines. 121.300 Section 121.300... MISCELLANEOUS SYSTEMS AND EQUIPMENT Mooring and Towing Equipment § 121.300 Ground tackle and mooring lines. A vessel must be fitted with ground tackle and mooring lines necessary for the vessel to be safely...

  13. 46 CFR 121.300 - Ground tackle and mooring lines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Ground tackle and mooring lines. 121.300 Section 121.300... MISCELLANEOUS SYSTEMS AND EQUIPMENT Mooring and Towing Equipment § 121.300 Ground tackle and mooring lines. A vessel must be fitted with ground tackle and mooring lines necessary for the vessel to be safely...

  14. 46 CFR 121.300 - Ground tackle and mooring lines.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Ground tackle and mooring lines. 121.300 Section 121.300... MISCELLANEOUS SYSTEMS AND EQUIPMENT Mooring and Towing Equipment § 121.300 Ground tackle and mooring lines. A vessel must be fitted with ground tackle and mooring lines necessary for the vessel to be safely...

  15. Tackling antibiotic resistance: the environmental framework.

    PubMed

    Berendonk, Thomas U; Manaia, Célia M; Merlin, Christophe; Fatta-Kassinos, Despo; Cytryn, Eddie; Walsh, Fiona; Bürgmann, Helmut; Sørum, Henning; Norström, Madelaine; Pons, Marie-Noëlle; Kreuzinger, Norbert; Huovinen, Pentti; Stefani, Stefania; Schwartz, Thomas; Kisand, Veljo; Baquero, Fernando; Martinez, José Luis

    2015-05-01

    Antibiotic resistance is a threat to human and animal health worldwide, and key measures are required to reduce the risks posed by antibiotic resistance genes that occur in the environment. These measures include the identification of critical points of control, the development of reliable surveillance and risk assessment procedures, and the implementation of technological solutions that can prevent environmental contamination with antibiotic resistant bacteria and genes. In this Opinion article, we discuss the main knowledge gaps, the future research needs and the policy and management options that should be prioritized to tackle antibiotic resistance in the environment.

  16. Tackling inequalities in health: the Australian experience.

    PubMed Central

    Whitehead, M; Judge, K; Hunter, D J; Maxwell, R; Scheuer, M A

    1993-01-01

    Federal and state governments in Australia have embarked on a series of national initiatives which show a firm commitment to tackling social inequalities in health. The development of national goals and targets for health, for example, covers social and environmental conditions and sets differential targets for specific social groups with very poor health status. In a complementary initiative, a wide ranging analysis of the health care system--the National Health Strategy--has as one of its main objectives to improve the equitable impact of the health system. Where problems of access to and quality of services have been exposed, policies have been devised to deal with them. The exceptionally poor health of the Aboriginal community has elicited cross party support for action. Resources have been allocated to implement the National Aboriginal Health Strategy: to improve living and working conditions, education, and employment opportunities. Britain can glean much from the Australian experience. Images p783-a p787-a PMID:8490345

  17. Plasma nanoscience: setting directions, tackling grand challenges

    NASA Astrophysics Data System (ADS)

    (Ken Ostrikov, Kostya; Cvelbar, Uros; Murphy, Anthony B.

    2011-05-01

    This review paper presents historical perspectives, recent advances and future directions in the multidisciplinary research field of plasma nanoscience. The current status and future challenges are presented using a three-dimensional framework. The first and the largest dimension covers the most important classes of nanoscale objects (nanostructures, nanofeatures and nanoassemblies/nanoarchitectures) and materials systems, namely carbon nanotubes, nanofibres, graphene, graphene nanoribbons, graphene nanoflakes, nanodiamond and related carbon-based nanostructures; metal, silicon and other inorganic nanoparticles and nanostructures; soft organic nanomaterials; nano-biomaterials; biological objects and nanoscale plasma etching. In the second dimension, we discuss the most common types of plasmas and plasma reactors used in nanoscale plasma synthesis and processing. These include low-temperature non-equilibrium plasmas at low and high pressures, thermal plasmas, high-pressure microplasmas, plasmas in liquids and plasma-liquid interactions, high-energy-density plasmas, and ionized physical vapour deposition as well as some other plasma-enhanced nanofabrication techniques. In the third dimension, we outline some of the 'Grand Science Challenges' and 'Grand Socio-economic Challenges' to which significant contributions from plasma nanoscience-related research can be expected in the near future. The urgent need for a stronger focus on practical, outcome-oriented research to tackle the grand challenges is emphasized and concisely formulated as from controlled complexity to practical simplicity in solving grand challenges.

  18. Malaysia urges ASEAN to tackle AIDS crisis.

    PubMed

    2000-08-07

    Urgent action is needed to fight the alarming spread of HIV/AIDS that infected 1.3 million people in Southeast Asia last year alone, Malaysia's foreign minister said July 24, 2000. Syed Hamid said the Association of Southeast Asian Nations (ASEAN) should tackle at regional and national level an epidemic that was taking its most drastic toll among the region's youth. "HIV/AIDS not only represents a major public health and social problem but is a serious challenge to development as well," Syed Hamid told the opening ceremony of ASEAN's 33rd annual foreign ministers' meeting. The crisis requires commitment at the "highest political level," he said, warning that HIV/AIDS could become a transnational problem within the 10-member group. Foreign ministers have recommended their leaders discuss the crisis later this year at an informal summit in Singapore and hold a summit on HIV/AIDS in conjunction with the 7th ASEAN Summit in Brunei next year. "I think people recognized the importance and the adverse impacts on our social development," Syed Hamid told reporters later. "I think it is a real issue that we cannot run away from." Among ASEAN members, Thailand, Cambodia, and Myanmar have some of the highest infection rates in Asia of HIV, the virus that causes AIDS.

  19. 46 CFR 121.300 - Ground tackle and mooring lines.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Ground tackle and mooring lines. 121.300 Section 121.300 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE... MISCELLANEOUS SYSTEMS AND EQUIPMENT Mooring and Towing Equipment § 121.300 Ground tackle and mooring lines....

  20. Severe and Catastrophic Neck Injuries Resulting from Tackle Football

    ERIC Educational Resources Information Center

    Torg, Joseph S.; And Others

    1977-01-01

    Use of the spring-loaded blocking and tackling devices should be discontinued due to severe neck injuries resulting from their use; employment of the head and helmet as the primary assault weapon in blocking, tackling, and head butting should be condemned for the same reason. (MJB)

  1. Tackling the organ donor shortage effectively: optimism or realism?

    PubMed

    Sheridan, Kelda; Farid, Shahid; Ahmad, Niaz

    2010-03-01

    There continues to be a growing disparity between the demand for and supply of organs for transplantation. This article reviews the status of current strategies in the UK to tackle the organ donor shortage.

  2. 2. VIEW OF BLOCK AND TACKLE FOR MOVING CEDAR LOGS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF BLOCK AND TACKLE FOR MOVING CEDAR LOGS FROM POND TO JACK LADDER--AN ENDLESS CHAIN CONVEYOR THAT MOVES LOGS INTO MILL - Lester Shingle Mill, 1602 North Eighteenth Street, Sweet Home, Linn County, OR

  3. Momentum and kinetic energy before the tackle in rugby union.

    PubMed

    Hendricks, Sharief; Karpul, David; Lambert, Mike

    2014-09-01

    Understanding the physical demands of a tackle in match situations is important for safe and effective training, developing equipment and research. Physical components such as momentum and kinetic energy, and it relationship to tackle outcome is not known. The aim of this study was to compare momenta between ball-carrier and tackler, level of play (elite, university and junior) and position (forwards vs. backs), and describe the relationship between ball-carrier and tackler mass, velocity and momentum and the tackle outcome. Also, report on the ball-carrier and tackler kinetic energy before contact and the estimated magnitude of impact (energy distributed between ball-carrier and tackler upon contact). Velocity over 0.5 seconds before contact was determined using a 2-dimensional scaled version of the field generated from a computer alogorithm. Body masses of players were obtained from their player profiles. Momentum and kinetic energy were subsequently calculated for 60 tackle events. Ball-carriers were heavier than the tacklers (ball-carrier 100 ± 14 kg vs. tackler 93 ± 11 kg, d = 0.52, p = 0.0041, n = 60). Ball-carriers as forwards had a significantly higher momentum than backs (forwards 563 ± 226 Kg(.)m(.)s(-1) n = 31 vs. backs 438 ± 135 Kg(.)m(.)s(-1), d = 0.63, p = 0.0012, n = 29). Tacklers dominated 57% of tackles and ball-carriers dominated 43% of tackles. Despite the ball-carrier having a mass advantage before contact more frequently than the tackler, momentum advantage and tackle dominance between the ball-carrier and tackler was proportionally similar. These findings may reflect a characteristic of the modern game of rugby where efficiently heavier players (particularly forwards) are tactically predetermined to carry the ball in contact. Key PointsFirst study to quantify momentum, kinetic energy, and magnitude of impact in rugby tackles across different levels in matches without a device attached to a player.Physical components alone, of either ball

  4. Momentum and Kinetic Energy Before the Tackle in Rugby Union

    PubMed Central

    Hendricks, Sharief; Karpul, David; Lambert, Mike

    2014-01-01

    Understanding the physical demands of a tackle in match situations is important for safe and effective training, developing equipment and research. Physical components such as momentum and kinetic energy, and it relationship to tackle outcome is not known. The aim of this study was to compare momenta between ball-carrier and tackler, level of play (elite, university and junior) and position (forwards vs. backs), and describe the relationship between ball-carrier and tackler mass, velocity and momentum and the tackle outcome. Also, report on the ball-carrier and tackler kinetic energy before contact and the estimated magnitude of impact (energy distributed between ball-carrier and tackler upon contact). Velocity over 0.5 seconds before contact was determined using a 2-dimensional scaled version of the field generated from a computer alogorithm. Body masses of players were obtained from their player profiles. Momentum and kinetic energy were subsequently calculated for 60 tackle events. Ball-carriers were heavier than the tacklers (ball-carrier 100 ± 14 kg vs. tackler 93 ± 11 kg, d = 0.52, p = 0.0041, n = 60). Ball-carriers as forwards had a significantly higher momentum than backs (forwards 563 ± 226 Kg.m.s-1 n = 31 vs. backs 438 ± 135 Kg.m.s-1, d = 0.63, p = 0.0012, n = 29). Tacklers dominated 57% of tackles and ball-carriers dominated 43% of tackles. Despite the ball-carrier having a mass advantage before contact more frequently than the tackler, momentum advantage and tackle dominance between the ball-carrier and tackler was proportionally similar. These findings may reflect a characteristic of the modern game of rugby where efficiently heavier players (particularly forwards) are tactically predetermined to carry the ball in contact. Key Points First study to quantify momentum, kinetic energy, and magnitude of impact in rugby tackles across different levels in matches without a device attached to a player. Physical components alone, of either ball-carrier or

  5. 46 CFR 184.300 - Ground tackle and mooring lines.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Ground tackle and mooring lines. 184.300 Section 184.300 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) VESSEL CONTROL AND MISCELLANEOUS SYSTEMS AND EQUIPMENT Mooring and Towing Equipment §...

  6. Using Invention to Change How Students Tackle Problems

    ERIC Educational Resources Information Center

    Taylor, Jared L.; Smith, Karen M.; van Stolk, Adrian P.; Spiegelman, George B.

    2010-01-01

    Invention activities challenge students to tackle problems that superficially appear unrelated to the course material but illustrate underlying fundamental concepts that are fundamental to material that will be presented. During our invention activities in a first-year biology class, students were presented with problems that are parallel to those…

  7. Sharon F. Clackum: tackling down-to-earth Priorities.

    PubMed

    Bloom, Marlene Z

    2014-11-01

    Sharon F. Clackum, incoming 2014-2015 ASCP president, will be tackling the down-to-earth priorities facing consultant pharmacists every day: improving medication therapy for older adults, increasing public awareness of the services they provide, and achieving recognition by Medicare as health professionals who need to be paid.

  8. The relationships between rugby players’ tackle training attitudes and behaviour and their match tackle attitudes and behaviour

    PubMed Central

    Hendricks, Sharief; den Hollander, Steve; Tam, Nicholas; Brown, James; Lambert, Michael

    2015-01-01

    Background The tackle event in rugby is a technical and physical contest between opposing players. A player's ability to tolerate and contest during a tackle is a prerequisite for safe participation and success in rugby. Little is known about the relationship between tackle training and tackling in matches in rugby union. Therefore, we investigated the relationships between players’ training attitudes and behaviour and their match attitudes and behaviour for tackling in rugby union. Method A questionnaire was designed to assess attitude (importance) and behaviours (frequency and quantity) among junior (under 19) players on a 5-point Likert Scale. Questionnaires were handed out to 220 players (10 schools) at a tournament and 75% (9 schools, n=164) were returned for analysis. Associations between training attitudes and behaviours were tested using the χ2 test, Cramer's V and τ-b. Results The more time spent on emphasising proper technique to prevent injuries in training, the more important players rated ‘own safety’ (τ-b=0.21, moderate, z=3.1, p<0.01), ‘going for the ball only’ (τ-b=0.27, moderate, z=4.6, p<0.001) and ‘staying on feet’ (τ-b=0.23, moderate, z=3.6, p<0.001) in match play. The more time spent on emphasising proper technique to improve performance in training, the more important players rated actions ‘going for ball only’ (τ-b=0.23, moderate, z=3.7, p<0.001) and ‘preventing the ball carrier from retaining position’ (τ-b=0.20, moderate, z=3.1, p<0.01) in match play. Conclusions This is the first study to report on the relationships between players’ training attitudes and behaviour and their match attitudes and behaviours for tackling in rugby union. The importance of tackle training to prevent injury, and the amount of time spent on technique to prevent injuries, was associated with behaviours that reduce the risk of injury in matches. PMID:27900133

  9. TSCA Section 21 Petition Requesting EPA to Regulate Lead in Fishing Tackle

    EPA Pesticide Factsheets

    This petition requests EPA to promulgate regulations under section 6 of TSCA to protect the environment from fishing tackle containing lead including fishing weights, sinkers, lures, jigs, and/or other tackle.

  10. 77 FR 10451 - Fishing Tackle Containing Lead; Disposition of Petition Filed Pursuant to TSCA Section 21

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-22

    ... to discourage the use of fishing tackle containing lead, to raise awareness of lead poisoning in... AGENCY 40 CFR Chapter I Fishing Tackle Containing Lead; Disposition of Petition Filed Pursuant to TSCA... applicable to fishing tackle containing lead (e.g., fishing weights, sinkers, lures, jigs, and/or...

  11. The Effects of Verbal Instruction and Shaping to Improve Tackling by High School Football Players

    ERIC Educational Resources Information Center

    Harrison, Antonio M.; Pyles, David A.

    2013-01-01

    We evaluated verbal instruction and shaping using TAG (teaching with acoustical guidance) to improve tackling by 3 high school football players. Verbal instruction and shaping improved tackling for all 3 participants. In addition, performance was maintained as participants moved more quickly through the tackling procedure.

  12. Tackling Trafficking by Targeting Sex Buyers: Can It Work?

    PubMed

    Niemi, Johanna; Aaltonen, Jussi

    2016-08-23

    The European legal instruments on human trafficking encourage states to tackle the demand for services of trafficked persons, for example, by making the use of services of a trafficked person a criminal offense. In Finland, buying sex from a trafficked person is a criminal offense. This article reports the results of an evaluation of the Finnish law and shows that the implementation has been inefficient. The authors argue that with an amendment of the law, the implementation could be improved but a truly efficient policy would require a total ban of sex purchase along the lines of the Swedish model.

  13. Tackle and impact detection in elite Australian football using wearable microsensor technology.

    PubMed

    Gastin, Paul B; McLean, Owen C; Breed, Ray V P; Spittle, Michael

    2014-01-01

    The effectiveness of a wearable microsensor device (MinimaxX(TM) S4, Catapult Innovations, Melbourne, VIC, Australia) to automatically detect tackles and impact events in elite Australian football (AF) was assessed during four matches. Video observation was used as the criterion measure. A total of 352 tackles were observed, with 78% correctly detected as tackles by the manufacturer's software. Tackles against (i.e. tackled by an opponent) were more accurately detected than tackles made (90% v 66%). Of the 77 tackles that were not detected at all, the majority (74%) were categorised as low-intensity. In contrast, a total of 1510 "tackle" events were detected, with only 18% of these verified as tackles. A further 57% were from contested ball situations involving player contact. The remaining 25% were in general play where no contact was evident; these were significantly lower in peak Player Load™ than those involving player contact (P < 0.01). The tackle detection algorithm, developed primarily for rugby, was not suitable for tackle detection in AF. The underlying sensor data may have the potential to detect a range of events within contact sports such as AF, yet to do so is a complex task and requires sophisticated sport and event-specific algorithms.

  14. Adaptive Online Sequential ELM for Concept Drift Tackling

    PubMed Central

    Basaruddin, Chan

    2016-01-01

    A machine learning method needs to adapt to over time changes in the environment. Such changes are known as concept drift. In this paper, we propose concept drift tackling method as an enhancement of Online Sequential Extreme Learning Machine (OS-ELM) and Constructive Enhancement OS-ELM (CEOS-ELM) by adding adaptive capability for classification and regression problem. The scheme is named as adaptive OS-ELM (AOS-ELM). It is a single classifier scheme that works well to handle real drift, virtual drift, and hybrid drift. The AOS-ELM also works well for sudden drift and recurrent context change type. The scheme is a simple unified method implemented in simple lines of code. We evaluated AOS-ELM on regression and classification problem by using concept drift public data set (SEA and STAGGER) and other public data sets such as MNIST, USPS, and IDS. Experiments show that our method gives higher kappa value compared to the multiclassifier ELM ensemble. Even though AOS-ELM in practice does not need hidden nodes increase, we address some issues related to the increasing of the hidden nodes such as error condition and rank values. We propose taking the rank of the pseudoinverse matrix as an indicator parameter to detect “underfitting” condition. PMID:27594879

  15. Tackling obesity: new therapeutic agents for assisted weight loss

    PubMed Central

    Karam, JG; McFarlane, SI

    2010-01-01

    The pandemic of overweight and obesity continues to rise in an alarming rate in western countries and around the globe representing a major public health challenge in desperate need for new strategies tackling obesity. In the United States nearly two thirds of the population is overweight or obese. Worldwide the number of persons who are overweight or obese exceeded 1.6 billion. These rising figures have been clearly associated with increased morbidity and mortality. For example, in the Framingham study, the risk of death increases with each additional pound of weight gain even in the relatively younger population between 30 and 42 years of age. Overweight and obesity are also associated with increased co-morbid conditions such as diabetes, hypertension and cardiovascular disease as well as certain types of cancer. In this review we discuss the epidemic of obesity, highlighting the pathophysiologic mechanisms of weight gain. We also provide an overview of the assessment of overweight and obese individuals discussing possible secondary causes of obesity. In a detailed section we discuss the currently approved therapeutic interventions for obesity highlighting their mechanisms of action and evidence of their efficacy and safety as provided in clinical trials. Finally, we discuss novel therapeutic interventions that are in various stages of development with a special section on the weight loss effects of anti-diabetic medications. These agents are particularly attractive options for our growing population of obese diabetic individuals. PMID:21437080

  16. Views on alternative forums for effectively tackling climate change

    NASA Astrophysics Data System (ADS)

    Hjerpe, Mattias; Nasiritousi, Naghmeh

    2015-09-01

    This year (2015) marks the 21st formal anniversary of the United Nations Framework Convention on Climate Change (UNFCCC) and in December a new climate treaty is expected to be reached. Yet, the UNFCCC has not been successful in setting the world on a path to meet a target to prevent temperatures rising by more than 2 °C above pre-industrial levels. Meanwhile, other forums, such as the G20 and subnational forums, have increasingly become sites of climate change initiatives. There has, however, so far been no systematic evaluation of what forums climate change policymakers and practitioners perceive to be needed to effectively tackle climate change. Drawing on survey data from two recent UNFCCC Conference of the Parties (COP), we show that there exists an overall preference for state-led, multilateral forums. However, preferences starkly diverge between respondents from different geographical regions and no clear alternative to the UNFCCC emerges. Our results highlight difficulties in coordinating global climate policy in a highly fragmented governance landscape.

  17. Tackling children's road safety through edutainment: an evaluation of effectiveness.

    PubMed

    Zeedyk, M S; Wallace, L

    2003-08-01

    The burgeoning market in electronic media has encouraged a trend toward 'edutainment', where entertaining, media-based materials are used to facilitate educational outcomes. In this study, we evaluated the effectiveness of a video that has recently been released by a popular children's entertainment group to help tackle Britain's poor record on children's road safety. We wished to determine whether the video had an impact on either children's knowledge or parents' awareness of pedestrian skills, when used in a standard home-based fashion. A total of 120 families participated, all of whom had children 5 years of age. Half the families received videos at the beginning of the study, while the other half served as a control group against which to measure change in the treatment group. Data were gathered at baseline and again 1 month later, using a series of tailored questionnaire items. A robust pattern of null findings indicated that the video, when used in this casual fashion, had no educational impact on either parents or children. Crucially, however, parents strongly believed that it had. The discussion explores the implications of such a mismatch and highlights similarities with outcomes of other health education interventions.

  18. Using invention to change how students tackle problems.

    PubMed

    Taylor, Jared L; Smith, Karen M; van Stolk, Adrian P; Spiegelman, George B

    2010-01-01

    Invention activities challenge students to tackle problems that superficially appear unrelated to the course material but illustrate underlying fundamental concepts that are fundamental to material that will be presented. During our invention activities in a first-year biology class, students were presented with problems that are parallel to those that living cells must solve, in weekly sessions over a 13-wk term. We compared students who participated in the invention activities sessions with students who participated in sessions of structured problem solving and with students who did not participate in either activity. When faced with developing a solution to a challenging and unfamiliar biology problem, invention activity students were much quicker to engage with the problem and routinely provided multiple reasonable hypotheses. In contrast the other students were significantly slower in beginning to work on the problem and routinely produced relatively few ideas. We suggest that the invention activities develop a highly valuable skill that operates at the initial stages of problem solving.

  19. Wind Turbine Failures - Tackling current Problems in Failure Data Analysis

    NASA Astrophysics Data System (ADS)

    Reder, M. D.; Gonzalez, E.; Melero, J. J.

    2016-09-01

    The wind industry has been growing significantly over the past decades, resulting in a remarkable increase in installed wind power capacity. Turbine technologies are rapidly evolving in terms of complexity and size, and there is an urgent need for cost effective operation and maintenance (O&M) strategies. Especially unplanned downtime represents one of the main cost drivers of a modern wind farm. Here, reliability and failure prediction models can enable operators to apply preventive O&M strategies rather than corrective actions. In order to develop these models, the failure rates and downtimes of wind turbine (WT) components have to be understood profoundly. This paper is focused on tackling three of the main issues related to WT failure analyses. These are, the non-uniform data treatment, the scarcity of available failure analyses, and the lack of investigation on alternative data sources. For this, a modernised form of an existing WT taxonomy is introduced. Additionally, an extensive analysis of historical failure and downtime data of more than 4300 turbines is presented. Finally, the possibilities to encounter the lack of available failure data by complementing historical databases with Supervisory Control and Data Acquisition (SCADA) alarms are evaluated.

  20. Tackling Cancer Stem Cells via Inhibition of EMT Transcription Factors

    PubMed Central

    Mladinich, Megan; Ruan, Diane

    2016-01-01

    Cancer stem cell (CSC) has become recognized for its role in both tumorigenesis and poor patient prognosis in recent years. Traditional therapeutics are unable to effectively eliminate this group of cells from the bulk population of cancer cells, allowing CSCs to persist posttreatment and thus propagate into secondary tumors. The therapeutic potential of eliminating CSCs, to decrease tumor relapse, has created a demand for identifying mechanisms that directly target and eliminate cancer stem cells. Molecular profiling has shown that cancer cells and tumors that exhibit the CSC phenotype also express genes associated with the epithelial-to-mesenchymal transition (EMT) feature. Ample evidence has demonstrated that upregulation of master transcription factors (TFs) accounting for the EMT process such as Snail/Slug and Twist can reprogram cancer cells from differentiated to stem-like status. Despite being appealing therapeutic targets for tackling CSCs, pharmacological approaches that directly target EMT-TFs remain impossible. In this review, we will summarize recent advances in the regulation of Snail/Slug and Twist at transcriptional, translational, and posttranslational levels and discuss the clinical implication and application for EMT blockade as a promising strategy for CSC targeting. PMID:27840647

  1. Cognition of an expert tackling an unfamiliar conceptual physics problem

    NASA Astrophysics Data System (ADS)

    Schuster, David; Undreiu, Adriana

    2009-11-01

    We have investigated and analyzed the cognition of an expert tackling a qualitative conceptual physics problem of an unfamiliar type. Our goal was to elucidate the detailed cognitive processes and knowledge elements involved, irrespective of final solution form, and consider implications for instruction. The basic but non-trivial problem was to find qualitatively the direction of acceleration of a pendulum bob at various stages of its motion, a problem originally studied by Reif and Allen. Methodology included interviews, introspection, retrospection and self-reported metacognition. Multiple facets of cognition were revealed, with different reasoning strategies used at different stages and for different points on the path. An account is given of the zigzag thinking paths and interplay of reasoning modes and schema elements involved. We interpret the cognitive processes in terms of theoretical concepts that emerged, namely: case-based, principle-based, experiential-intuitive and practical-heuristic reasoning; knowledge elements and schemata; activation; metacognition and epistemic framing. The complexity of cognition revealed in this case study contrasts with the tidy principle-based solutions we present to students. The pervasive role of schemata, case-based reasoning, practical heuristic strategies, and their interplay with physics principles is noteworthy, since these aspects of cognition are generally neither recognized nor taught. The schema/reasoning-mode perspective has direct application in science teaching, learning and problem-solving.

  2. Lead fishing weights and other fishing tackle in selected waterbirds

    USGS Publications Warehouse

    Franson, J.C.; Hansen, Scott P.; Creekmore, T.E.; Brand, C.J.; Evers, D.C.; Duerr, A.E.; DeStefano, S.

    2003-01-01

    From 1995 through 1999, 2,240 individuals of 28 species of waterbirds were examined in the United States for ingested lead fishing weights. A combination of radiography and visual examination of stomachs was used to search for lead weights and blood and liver samples from live birds and carcasses, respectively, were collected for lead analysis. Ingested lead weights were found most frequently in the Common Loon (Gavia immer) (11 of 313 = 3.5%) and Brown Pelican (Pelecanus occidentalis) (10 of 365 = 2.7%), but also in one of 81 (1.2%) Double-crested Cormorants (Phalacrocorax auritus) and one of 11 (9.1%) Black-crowned Night Herons (Nycticorax nycticorax). Birds with ingested lead fishing weights (including split shot, jig heads, and egg, bell, and pyramid sinkers) were found in California, Florida, Maine, New Hampshire, North Carolina, and Wisconsin. The size and mass of ingested lead weights ranged from split shot of 7 mm in the longest dimension, weighing less than 2 g, to a 22 ?? 39 mm pyramid sinker that weighed 78.2 g. Six ingested lead weights were more than 25.4 mm in the longest dimension. Lead concentrations in the blood and liver of birds with lead fishing weights in their stomachs ranged up to 13.9 ppm and 26.0 ppm (wet weight basis), respectively. During the study, we also noted the presence of ingested or entangled fishing tackle, with no associated lead weights, in eight species.

  3. Muscular Strength and Power Correlates of Tackling Ability in Semiprofessional Rugby League Players.

    PubMed

    Speranza, Michael J A; Gabbett, Tim J; Johnston, Rich D; Sheppard, Jeremy M

    2015-08-01

    This study investigated the relationship between muscular strength and power and tackling ability in semiprofessional rugby league players. Thirty-six semiprofessional (mean ± SD age, 23.1 ± 3.6 years) rugby league players, from 3 distinct playing divisions (first grade, second grade, and under 20s), underwent tests of upper-body strength (3 repetition maximum [RM] bench press), lower-body strength (3RM squat), upper-body power (plyometric push-up [PPU]), and lower-body power (countermovement jump). Muscular strength relative to body mass was also calculated. Tackling ability of the players was tested using video analysis of a standardized one-on-one tackling drill. For all players, the strongest correlates of tackling ability were squat (r = 0.67), bench press (r = 0.58), relative squat (r = 0.41), and PPU (r = 0.56). The strongest correlates of tackling ability in first grade players were squat (r = 0.72), bench press (r = 0.72), relative squat (r = 0.86), and PPU (r = 0.70). For second grade players, only relative squat (r = 0.60) and PPU (r = 0.67) were associated with tackling ability. The strongest correlates of tackling ability in under 20s players were squat (r = 0.77), bench press (r = 0.70), and PPU (r = 0.65). The findings of this study demonstrate that muscular strength and upper-body power contribute to tackling ability in semiprofessional rugby league players. Therefore, as long as the technical aspects of tackling technique are adequately coached and practiced, then enhancements in muscular strength and power may serve as foundational components to underpin improvement in tackling ability.

  4. Tackling the Triple-Threat Genome of Miscanthus x giganteus (2010 JGI User Meeting)

    SciTech Connect

    Moose, Steve

    2010-03-25

    Steve Moose from the University of Illinois at Urbana-Champaign and the Energy Biosciences Institute on "Tackling the Triple-Threat Genome of Miscanthus x giganteus" on March 25, 2010 at the 5th Annual DOE JGI User Meeting

  5. Tackling the Triple-Threat Genome of Miscanthus x giganteus (2010 JGI User Meeting)

    ScienceCinema

    Moose, Steve

    2016-07-12

    Steve Moose from the University of Illinois at Urbana-Champaign and the Energy Biosciences Institute on "Tackling the Triple-Threat Genome of Miscanthus x giganteus" on March 25, 2010 at the 5th Annual DOE JGI User Meeting

  6. 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.

  7. 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.

  8. Tackling emerging fungal threats to animal health, food security and ecosystem resilience

    PubMed Central

    Gow, Neil A. R.; Gurr, Sarah J.

    2016-01-01

    Emerging infections caused by fungi have become a widely recognized global phenomenon. Their notoriety stems from their causing plagues and famines, driving species extinctions, and the difficulty in treating human mycoses alongside the increase of their resistance to antifungal drugs. This special issue comprises a collection of articles resulting from a Royal Society discussion meeting examining why pathogenic fungi are causing more disease now than they did in the past, and how we can tackle this rapidly emerging threat to the health of plants and animals worldwide. This article is part of the themed issue ‘Tackling emerging fungal threats to animal health, food security and ecosystem resilience’. PMID:28080997

  9. Towards an Evidence-Based Approach to Tackling Health Inequalities: The English Experience

    ERIC Educational Resources Information Center

    Killoran, Amanda; Kelly, Michael

    2004-01-01

    This short paper considers the development of an evidence-based approach to tackling health inequalities. Inequalities in health in England at the beginning of the 21st century have widened and are stark. Despite overall improvements in death rates, the growing gap between social groups means that now some parts of England have the same levels of…

  10. Tackling Behaviour in Your Primary School: A Practical Handbook for Teachers

    ERIC Educational Resources Information Center

    Reid, Ken; Morgan, Nicola S.

    2012-01-01

    "Tackling Behaviour in the Primary School" provides ready-made advice and support for classroom professionals and can be used, read and adapted to suit the busy everyday lives of teachers working in primary schools today. This valuable text sets the scene for managing behaviour in the primary classroom in the context of the Children Act 2004…

  11. Beyond Individual Behaviour Change: The Role of Power, Knowledge and Strategy in Tackling Climate Change

    ERIC Educational Resources Information Center

    Kenis, Anneleen; Mathijs, Erik

    2012-01-01

    Individual behaviour change is fast becoming a kind of "holy grail" to tackle climate change, in environmental policy, the environmental movement and academic literature. This is contested by those who claim that social structures are the main problem and who advocate collective social action. The objective of the research presented in…

  12. Are Elementary School Teachers Prepared to Tackle Bullying? A Pilot Study

    ERIC Educational Resources Information Center

    Oldenburg, Beau; Bosman, Rie; Veenstra, René

    2016-01-01

    The aim of this pilot study was to investigate to what extent elementary school teachers were prepared to tackle bullying. Interview data from 22 Dutch elementary school teachers (M[subscript age]?=?43.3, 18 classrooms in eight schools) were combined with survey data from 373 students of these teachers (M age?=?10.7, grades 3-6, ages 8- to…

  13. Influence of Fatigue on Tackling Ability in Rugby League Players: Role of Muscular Strength, Endurance, and Aerobic Qualities

    PubMed Central

    Gabbett, Tim J.

    2016-01-01

    This study investigated the influence of repeated high-intensity effort exercise on tackling ability in rugby league players, and determined the relationship between physical qualities and tackling ability under fatigued conditions in these athletes. Eleven semi-professional rugby league players underwent measurements of speed (10 m and 40 m sprint), upper-body strength (4 repetition maximum [RM] bench press and weighted chin-up), upper-body muscular endurance (body mass maximum repetition chin-up, body mass maximum repetition dips), lower-body strength (4RM squat), and estimated maximal aerobic power (multi-stage fitness test). Tackling ability was assessed using a standardized one-on-one tackling test, before, during, and following four bouts of repeated high-intensity effort (RHIE) exercise. The relationship between physical qualities and fatigue-induced decrements in tackling ability were determined using Pearson product moment correlation coefficients. Each cycle of the RHIE protocol induced progressive reductions in tackling ability. A moderate reduction (Effect Size = ~-1.17 ± 0.60, -34.1 ± 24.3%) in tackling ability occurred after the fourth cycle of the RHIE protocol. Players with greater relative lower-body strength (i.e. 4RM squat/kg) had the best tackling ability under fatigued conditions (r = 0.72, p = 0.013). There were no significant relationships between tackling ability under fatigued conditions and any other physical quality. These findings suggest that lower-body strength protects against fatigue-induced decrements in tackling ability. The development of lower-body strength should be a priority to facilitate the development of robust tackling skills that are maintained under fatigue. PMID:27798634

  14. Tackling Targets.

    ERIC Educational Resources Information Center

    Further Education Unit, London (England).

    This document is designed to help British training and enterprise councils (TECs) and further education (FE) colleges develop and implement strategies for achieving the National Targets for Education and Training (NTET), which were developed by the Confederation of British Industry in 1992 and endorsed by the British government. The findings from…

  15. 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

  16. 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

  17. Early Results of a Helmetless-Tackling Intervention to Decrease Head Impacts in Football Players

    PubMed Central

    Swartz, Erik E.; Broglio, Steven P.; Cook, Summer B.; Cantu, Robert C.; Ferrara, Michael S.; Guskiewicz, Kevin M.; Myers, Jay L.

    2015-01-01

    Objective To test a helmetless-tackling behavioral intervention for reducing head impacts in National Collegiate Athletic Association Division I football players. Design Randomized controlled clinical trial. Setting Football field. Patients or Other Participants Fifty collegiate football players (intervention = 25, control = 25). Intervention(s) The intervention group participated in a 5-minute tackling drill without their helmets and shoulder pads twice per week in the preseason and once per week through the season. During this time, the control group performed noncontact football skills. Main Outcome Measure(s) Frequency of head impacts was recorded by an impact sensor for each athlete-exposure (AE). Data were tested with a 2 × 3 (group and time) repeated-measures analysis of variance. Significant interactions and main effects (P < .05) were followed with t tests. Results Head impacts/AE decreased for the intervention group compared with the control group by the end of the season (9.99 ± 6.10 versus 13.84 ± 7.27, respectively). The intervention group had 30% fewer impacts/AE than the control group by season's end (9.99 ± 6.10 versus 14.32 ± 8.45, respectively). Conclusion A helmetless-tackling training intervention reduced head impacts in collegiate football players within 1 season. PMID:26651278

  18. Microbial responses to southward and northward Cambisol soil transplant.

    PubMed

    Wang, Mengmeng; Liu, Shanshan; Wang, Feng; Sun, Bo; Zhou, Jizhong; Yang, Yunfeng

    2015-12-01

    Soil transplant serves as a proxy to simulate climate changes. Recently, we have shown that southward transplant of black soil and northward transplant of red soil altered soil microbial communities and biogeochemical variables. However, fundamental differences in soil types have prevented direct comparison between southward and northward transplants. To tackle it, herein we report an analysis of microbial communities of Cambisol soil in an agriculture field after 4 years of adaptation to southward and northward soil transplants over large transects. Analysis of bare fallow soils revealed concurrent increase in microbial functional diversity and coarse-scale taxonomic diversity at both transplanted sites, as detected by GeoChip 3.0 and DGGE, respectively. Furthermore, a correlation between microbial functional diversity and taxonomic diversity was detected, which was masked in maize cropped soils. Mean annual temperature, soil moisture, and nitrate (NO3 ¯-N) showed strong correlations with microbial communities. In addition, abundances of ammonium-oxidizing genes (amoA) and denitrification genes were correlated with nitrification capacity and NO3 ¯-N contents, suggesting that microbial responses to soil transplant could alter microbe-mediated biogeochemical cycle at the ecosystem level.

  19. Augmentation of a Microbial Consortium for Enhanced Polylactide (PLA) Degradation.

    PubMed

    Nair, Nimisha R; Sekhar, Vini C; Nampoothiri, K Madhavan

    2016-03-01

    Bioplastics are eco-friendly and derived from renewable biomass sources. Innovation in recycling methods will tackle some of the critical issues facing the acceptance of bioplastics. Polylactic acid (PLA) is the commonly used and well-studied bioplastic that is presumed to be biodegradable. Considering their demand and use in near future, exploration for microbes capable of bioplastic degradation has high potential. Four PLA degrading strains were isolated and identified as Penicillium chrysogenum, Cladosporium sphaerospermum, Serratia marcescens and Rhodotorula mucilaginosa. A consortium of above strains degraded 44 % (w/w) PLA in 30 days time in laboratory conditions. Subsequently, the microbial consortium employed effectively for PLA composting.

  20. Role of public-private partnerships in tackling the tobacco and obesity epidemics.

    PubMed

    Parekh, Anand K; Scott, Alicia Richmond; McMahon, Catherine; Teel, Calvin

    2014-06-12

    In response to the illness and death caused by preventable chronic diseases, the US Department of Health and Human Services created Communities Putting Prevention to Work to support community efforts in tackling tobacco use and obesity through policy, systems, and environmental change. As part of this program, 10 national nonprofit organizations with prevention expertise were funded and matched with specific community objectives. Most tobacco and obesity-related matched objectives were successfully accomplished by communities. Public-private partnerships should be considered when addressing chronic disease prevention.

  1. Tackling the x-ray cargo inspection challenge using machine learning

    NASA Astrophysics Data System (ADS)

    Jaccard, Nicolas; Rogers, Thomas W.; Morton, Edward J.; Griffin, Lewis D.

    2016-05-01

    The current infrastructure for non-intrusive inspection of cargo containers cannot accommodate exploding com-merce volumes and increasingly stringent regulations. There is a pressing need to develop methods to automate parts of the inspection workflow, enabling expert operators to focus on a manageable number of high-risk images. To tackle this challenge, we developed a modular framework for automated X-ray cargo image inspection. Employing state-of-the-art machine learning approaches, including deep learning, we demonstrate high performance for empty container verification and specific threat detection. This work constitutes a significant step towards the partial automation of X-ray cargo image inspection.

  2. High School Football Players Use Their Helmets to Tackle Other Players Despite Knowing the Risks

    PubMed Central

    Kuriyama, Andrew M; Nakatsuka, Austin S

    2017-01-01

    There is greater attention to head-related injuries and concussions in American football. The helmet's structural safety and the way that football players use their helmets are important in preventing head injuries. Current strategies include penalizing players for high-risk behavior such as leading with their helmet or hitting an opposing player above the shoulder. Passive strategies include helmet modification to better protect the head of the players or to change the playing style of the players. Hawai‘i high school varsity football players were surveyed to determine how they use their helmets and how a new helmet design would affect their style of play. One hundred seventy-seven surveys were completed; 79% said that they used their helmet to hit an opposing player during a tackle and 46% said they made this contact intentionally. When asked about modifying helmets with a soft material on the outside, 48% said they thought putting a soft cover over a regular helmet would protect their head better. However, many participants said that putting a soft cover over their regular helmet was a bad idea for various reasons. Most young football players use their helmets to block or tackle despite being taught they would be penalized or potentially injured if they did so. By gaining a better understanding of why and how players use their helmets and how they would respond to new helmet designs, steps can be taken to reduce head injuries for all levels of play. PMID:28352493

  3. Social and health policies or interventions to tackle health inequalities in European cities: a scoping review

    PubMed Central

    2014-01-01

    Background Health inequalities can be tackled with appropriate health and social policies, involving all community groups and governments, from local to global. The objective of this study was to carry out a scoping review on social and health policies or interventions to tackle health inequalities in European cities published in scientific journals. Methods Scoping review. The search was done in “PubMed” and the “Sociological Abstracts” database and was limited to articles published between 1995 and 2011. The inclusion criteria were: interventions had to take place in European cities and they had to state the reduction of health inequalities among their objectives. Results A total of 54 papers were included, of which 35.2% used an experimental design, and 74.1% were carried out in the United Kingdom. The whole city was the setting in 27.8% of them and 44.4% were based on promoting healthy behaviours. Adults and children were the most frequent target population and half of the interventions had a universal approach and the other half a selective one. Half of the interventions were evaluated and showed positive results. Conclusions Although health behaviours are not the main determinants of health inequalities, the majority of the selected documents were based on evaluations of interventions focusing on them. PMID:24564851

  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. Applying the emergency risk management process to tackle the crisis of antibiotic resistance

    PubMed Central

    Dominey-Howes, Dale; Bajorek, Beata; Michael, Carolyn A.; Betteridge, Brittany; Iredell, Jonathan; Labbate, Maurizio

    2015-01-01

    We advocate that antibiotic resistance be reframed as a disaster risk management problem. Antibiotic-resistant infections represent a risk to life as significant as other commonly occurring natural disasters (e.g., earthquakes). Despite efforts by global health authorities, antibiotic resistance continues to escalate. Therefore, new approaches and expertise are needed to manage the issue. In this perspective we: (1) make a call for the emergency management community to recognize the antibiotic resistance risk and join in addressing this problem; (2) suggest using the risk management process to help tackle antibiotic resistance; (3) show why this approach has value and why it is different to existing approaches; and (4) identify public perception of antibiotic resistance as an important issue that warrants exploration. PMID:26388864

  6. Deliberative Mapping of options for tackling climate change: Citizens and specialists 'open up' appraisal of geoengineering.

    PubMed

    Bellamy, Rob; Chilvers, Jason; Vaughan, Naomi E

    2016-04-01

    Appraisals of deliberate, large-scale interventions in the earth's climate system, known collectively as 'geoengineering', have largely taken the form of narrowly framed and exclusive expert analyses that prematurely 'close down' upon particular proposals. Here, we present the findings from the first 'upstream' appraisal of geoengineering to deliberately 'open up' to a broader diversity of framings, knowledges and future pathways. We report on the citizen strand of an innovative analytic-deliberative participatory appraisal process called Deliberative Mapping. A select but diverse group of sociodemographically representative citizens from Norfolk (United Kingdom) were engaged in a deliberative multi-criteria appraisal of geoengineering proposals relative to other options for tackling climate change, in parallel to symmetrical appraisals by diverse experts and stakeholders. Despite seeking to map divergent perspectives, a remarkably consistent view of option performance emerged across both the citizens' and the specialists' deliberations, where geoengineering proposals were outperformed by mitigation alternatives.

  7. Synthetic biology approaches to biological containment: pre-emptively tackling potential risks

    PubMed Central

    Krüger, Antje; Csibra, Eszter; Gianni, Edoardo

    2016-01-01

    Biocontainment comprises any strategy applied to ensure that harmful organisms are confined to controlled laboratory conditions and not allowed to escape into the environment. Genetically engineered microorganisms (GEMs), regardless of the nature of the modification and how it was established, have potential human or ecological impact if accidentally leaked or voluntarily released into a natural setting. Although all evidence to date is that GEMs are unable to compete in the environment, the power of synthetic biology to rewrite life requires a pre-emptive strategy to tackle possible unknown risks. Physical containment barriers have proven effective but a number of strategies have been developed to further strengthen biocontainment. Research on complex genetic circuits, lethal genes, alternative nucleic acids, genome recoding and synthetic auxotrophies aim to design more effective routes towards biocontainment. Here, we describe recent advances in synthetic biology that contribute to the ongoing efforts to develop new and improved genetic, semantic, metabolic and mechanistic plans for the containment of GEMs. PMID:27903826

  8. Quantitative nanoscopy: Tackling sampling limitations in (S)TEM imaging of polymers and composites.

    PubMed

    Gnanasekaran, Karthikeyan; Snel, Roderick; de With, Gijsbertus; Friedrich, Heiner

    2016-01-01

    Sampling limitations in electron microscopy questions whether the analysis of a bulk material is representative, especially while analyzing hierarchical morphologies that extend over multiple length scales. We tackled this problem by automatically acquiring a large series of partially overlapping (S)TEM images with sufficient resolution, subsequently stitched together to generate a large-area map using an in-house developed acquisition toolbox (TU/e Acquisition ToolBox) and stitching module (TU/e Stitcher). In addition, we show that quantitative image analysis of the large scale maps provides representative information that can be related to the synthesis and process conditions of hierarchical materials, which moves electron microscopy analysis towards becoming a bulk characterization tool. We demonstrate the power of such an analysis by examining two different multi-phase materials that are structured over multiple length scales.

  9. Waste collection in developing countries--tackling occupational safety and health hazards at their source.

    PubMed

    Bleck, Daniela; Wettberg, Wieland

    2012-11-01

    Waste management procedures in developing countries are associated with occupational safety and health risks. Gastro-intestinal infections, respiratory and skin diseases as well as muscular-skeletal problems and cutting injuries are commonly found among waste workers around the globe. In order to find efficient, sustainable solutions to reduce occupational risks of waste workers, a methodological risk assessment has to be performed and counteractive measures have to be developed according to an internationally acknowledged hierarchy. From a case study in Addis Ababa, Ethiopia suggestions for the transferral of collected household waste into roadside containers are given. With construction of ramps to dump collected household waste straight into roadside containers and an adaptation of pushcarts and collection procedures, the risk is tackled at the source.

  10. Redesigning Primary Care to Tackle the Global Epidemic of Noncommunicable Disease

    PubMed Central

    Nigenda, Gustavo; Knaul, Felicia M.

    2015-01-01

    Noncommunicable diseases (NCDs) have become the major contributors to death and disability worldwide. Nearly 80% of the deaths in 2010 occurred in low- and middle-income countries, which have experienced rapid population aging, urbanization, rise in smoking, and changes in diet and activity. Yet the health systems of low- and middle-income countries, historically oriented to infectious disease and often severely underfunded, are poorly prepared for the challenge of caring for people with cardiovascular disease, diabetes, cancer, and chronic respiratory disease. We have discussed how primary care can be redesigned to tackle the challenge of NCDs in resource-constrained countries. We suggest that four changes will be required: integration of services, innovative service delivery, a focus on patients and communities, and adoption of new technologies for communication. PMID:25602898

  11. Emerging nutrition challenges: policies to tackle under-nutrition, obesity and chronic diseases.

    PubMed

    Coitinho, Denise Costa; Rivera, Juan A; Uauy, Ricardo; Ding, Zong-Yi; Ruel, Marie T; Svensson, Per-Gunnar

    2008-01-01

    On 19 May, 2008, Mexico's Secretary of Health, Dr José Angel Córdova Villalobos, hosted an event entitled Emerging Nutrition Challenges: Policies to Tackle Under-nutrition, Obesity and Chronic Diseases. Held in conjunction with the World Health Assembly (WHA) in Geneva, nearly 100 delegates from over 30 countries attended. The International Association of Infant Food Manufacturers and the International Hospital Federation supported Mexico in its sponsorship of this event. Dr Villalobos provided opening remarks including an overview of Mexico's public policies to prevent obesity and chronic diseases. Dr. Mauricio Hernández, Mexico's Undersecretary of Health, moderated as six experts from around the world spoke on issues relating to the nutrition "double burden" (i.e. malnourishment and obesity), successful interventions and policy opportunities for improving nutrition, preventing obesity and enhancing health outcomes. Following are abstracts from their presentations.

  12. Improving psychosexual knowledge in adolescents with autism spectrum disorder: pilot of the tackling teenage training program.

    PubMed

    Dekker, Linda P; van der Vegt, Esther J M; Visser, Kirsten; Tick, Nouchka; Boudesteijn, Frieda; Verhulst, Frank C; Maras, Athanasios; Greaves-Lord, Kirstin

    2015-06-01

    Previous studies have shown that psychosexual functioning in adolescents with autism spectrum disorder (ASD) is hampered and emphasize the need for a specialized training program tailored to their needs. Therefore, an individual training program was developed; the Tackling Teenage Training (TTT) program. The current pilot study systematically evaluated whether psychosexual knowledge increased after taking part in the TTT program, using a pre- and post-training design in 30 adolescents with ASD (77 % male, mean age = 14.80 years, mean intelligence = 96.96). Psychosexual knowledge increased significantly (pre-training total score: M = 25.74, SD = 6.20; post-training total score: M = 33.52 (SD = 2.78); F(1,29) = 65.20, p < .001). The TTT program may be useful to improve psychosexual knowledge and functioning in adolescents with ASD, yet these findings are preliminary, and a more elaborate controlled trial is needed.

  13. Waste collection in developing countries - Tackling occupational safety and health hazards at their source

    SciTech Connect

    Bleck, Daniela; Wettberg, Wieland

    2012-11-15

    Waste management procedures in developing countries are associated with occupational safety and health risks. Gastro-intestinal infections, respiratory and skin diseases as well as muscular-skeletal problems and cutting injuries are commonly found among waste workers around the globe. In order to find efficient, sustainable solutions to reduce occupational risks of waste workers, a methodological risk assessment has to be performed and counteractive measures have to be developed according to an internationally acknowledged hierarchy. From a case study in Addis Ababa, Ethiopia suggestions for the transferral of collected household waste into roadside containers are given. With construction of ramps to dump collected household waste straight into roadside containers and an adaptation of pushcarts and collection procedures, the risk is tackled at the source.

  14. The persistent problem of lead poisoning in birds from ammunition and fishing tackle

    USGS Publications Warehouse

    Haig, Susan M.; D'Elia, Jesse; Eagles-Smith, Collin; Fair, Jeanne M.; Gervais, Jennifer; Herring, Garth; Rivers, James W.; Schulz, John H.

    2014-01-01

    Lead (Pb) is a metabolic poison that can negatively influence biological processes, leading to illness and mortality across a large spectrum of North American avifauna (>120 species) and other organisms. Pb poisoning can result from numerous sources, including ingestion of bullet fragments and shot pellets left in animal carcasses, spent ammunition left in the field, lost fishing tackle, Pb-based paints, large-scale mining, and Pb smelting activities. Although Pb shot has been banned for waterfowl hunting in the United States (since 1991) and Canada (since 1999), Pb exposure remains a problem for many avian species. Despite a large body of scientific literature on exposure to Pb and its toxicological effects on birds, controversy still exists regarding its impacts at a population level. We explore these issues and highlight areas in need of investigation: (1) variation in sensitivity to Pb exposure among bird species; (2) spatial extent and sources of Pb contamination in habitats in relation to bird exposure in those same locations; and (3) interactions between avian Pb exposure and other landscape-level stressors that synergistically affect bird demography. We explore multiple paths taken to reduce Pb exposure in birds that (1) recognize common ground among a range of affected interests; (2) have been applied at local to national scales; and (3) engage governmental agencies, interest groups, and professional societies to communicate the impacts of Pb ammunition and fishing tackle, and to describe approaches for reducing their availability to birds. As they have in previous times, users of fish and wildlife will play a key role in resolving the Pb poisoning issue.

  15. Tackling malnutrition in Latin America and the Caribbean: challenges and opportunities.

    PubMed

    Galicia, Luis; de Romaña, Daniel López; Harding, Kimberly B; De-Regil, Luz María; Grajeda, Rubén

    2016-08-01

    Undernutrition and micronutrient deficiencies are still a public health problem in Latin America and the Caribbean (LAC), and overweight and obesity have reached epidemic proportions. To assess the nutrition landscape in LAC countries and guide future nutrition efforts and investments, the Pan American Health Organization and the Micronutrient Initiative joined efforts to 1) identify information gaps and describe the current nutritional situation in the region; 2) map existing policies to address malnutrition in Latin America; 3) describe the impact of conditional cash transfer programs (CCTs) on nutrition and health outcomes; and 4) identify the challenges and opportunities to address malnutrition in the region. This article summarizes the methods and key findings from that research and describes the current challenges and opportunities in addressing malnutrition in the LAC region. LAC countries have advanced in reducing undernutrition and micronutrient deficiencies, but important gaps in information are a major concern. These countries have policies to address undernutrition and micronutrient deficiencies, but comprehensive and intersectoral policies to tackle obesity are lacking. CCTs in Brazil, Colombia, and Mexico have been reported to have a positive impact on child nutrition and health outcomes, providing an opportunity to integrate nutrition actions in intersectoral platforms. The current epidemiological situation and policy options offer an opportunity for countries, technical agencies, donors, and other stakeholders to jointly scale up nutrition actions. This can support the development of comprehensive and intersectoral policies to tackle the double burden of malnutrition, strengthen national nutrition surveillance systems, incorporate monitoring and evaluation as systematic components of policies and programs, document and increase investments in nutrition, and assess the effectiveness of such policies to support political commitment and guarantee

  16. Tackling Health Inequalities in the United Kingdom: The Progress and Pitfalls of Policy

    PubMed Central

    Exworthy, Mark; Blane, David; Marmot, Michael

    2003-01-01

    Goal Assess the progress and pitfalls of current United Kingdom (U.K.) policies to reduce health inequalities. Objectives (1) Describe the context enabling health inequalities to get onto the policy agenda in the United Kingdom. (2) Categorize and assess selected current U.K. policies that may affect health inequalities. (3) Apply the “policy windows” model to understand the issues faced in formulating and implementing such policies. (4) Examine the emerging policy challenges in the U.K. and elsewhere. Data Sources Official documents, secondary analyses, and interviews with policymakers. Study Design Qualitative, policy analysis. Data Collection 2001–2002. The methods were divided into two stages. The first identified policies which were connected with individual inquiry recommendations. The second involved case-studies of three policies areas which were thought to be crucial in tackling health inequalities. Both stages involved interviews with policy-makers and documentary analysis. Principal Findings (1) The current U.K. government stated a commitment to reducing health inequalities. (2) The government has begun to implement policies that address the wider determinants. (3) Some progress is evident but many indicators remain stubborn. (4) Difficulties remain in terms of coordinating policies across government and measuring progress. (5) The “policy windows” model explains the limited extent of progress and highlights current and possible future pitfalls. (6) The U.K.'s experience has lessons for other governments involved in tackling health inequalities. Conclusions Health inequalities are on the agenda of U.K. government policy and steps have been made to address them. There are some signs of progress but much remains to be done including overcoming some of the perverse incentives at the national level, improving joint working, ensuring appropriate measures of performance/progress, and improving monitoring arrangements. A conceptual policy model aids

  17. 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...

  18. 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.

  19. Can Smoking Cessation Services Be Better Targeted to Tackle Health Inequalities? Evidence from a Cross-Sectional Study

    ERIC Educational Resources Information Center

    Blackman, Tim

    2008-01-01

    Objective: To investigate how smoking cessation services could be more effectively targeted to tackle socioeconomic inequalities in health. Design: Secondary analysis of data from a household interview survey undertaken for Middlesbrough Council in north east England using the technique of Qualitative Comparative Analysis. Setting: Home-based…

  20. Caught in the (Education) Act: Tackling Michael Gove's Education Revolution. Report on 19th November 2011 Conference

    ERIC Educational Resources Information Center

    FORUM: for promoting 3-19 comprehensive education, 2012

    2012-01-01

    A number of significant campaigning organisations and education trades unions--the Anti-Academies Alliance, CASE, Comprehensive Future, Forum, ISCG and the Socialist Educational Association, along with ASCL, ATL, NASUWT and NUT--staged a conference in London on 19 November 2011, with the title 'Caught in the (Education) Act: tackling Michael…

  1. Transgressive Local Act: Tackling Domestic Violence with Forum and Popular Theatre in "Sisterhood Bound as Yuan Ze Flowers"

    ERIC Educational Resources Information Center

    Wang, Wan-Jung

    2010-01-01

    This paper examines a community theatre project in Kaohsiung County, Taiwan that aimed to tackle domestic violence through a collaboration between local community female elders and the facilitator. The paper investigates how an outside facilitator could unfix the assumed community identities which tend to exclude outsiders or sub-groups, in this…

  2. African schistosomiasis in mainland China: risk of transmission and countermeasures to tackle the risk.

    PubMed

    Wang, Wei; Liang, You-Sheng; Hong, Qing-Biao; Dai, Jian-Rong

    2013-08-28

    Schistosomiasis is a major disease of public health importance in humans occurring in 76 countries of the tropics and sub-tropics. In China, schistosomiasis japonica is one of the highest priorities in communicable disease control defined by the central government. Since 1970s, the habitats of Biomphalaria straminea, an intermediate host of Schistosoma mansoni in South America, have been identified in Hong Kong Special Administrative Region and Shenzhen city, Guangdong province of China. With the sharp growth in the China-aided projects in Africa and labor services export to Africa, a gradual rise in the cases infected with S. haematobium or S. mansoni is reported in those returning from Africa to China. The existence of intermediate snail hosts and import of infectious source of schistosomiasis results in concern about the transmission of African schistosomiasis in mainland China in the context of global climate change. This paper evaluates the risk of transmission of African schistosomiasis in China, and proposes countermeasures and research priorities to tackle the risk.

  3. Benchmarking progress in tackling the challenges of intellectual property, and access to medicines in developing countries.

    PubMed

    Musungu, Sisule F

    2006-05-01

    The impact of intellectual property protection in the pharmaceutical sector on developing countries has been a central issue in the fierce debate during the past 10 years in a number of international fora, particularly the World Trade Organization (WTO) and WHO. The debate centres on whether the intellectual property system is: (1) providing sufficient incentives for research and development into medicines for diseases that disproportionately affect developing countries; and (2) restricting access to existing medicines for these countries. The Doha Declaration was adopted at WTO in 2001 and the Commission on Intellectual Property, Innovation and Public Health was established at WHO in 2004, but their respective contributions to tackling intellectual property-related challenges are disputed. Objective parameters are needed to measure whether a particular series of actions, events, decisions or processes contribute to progress in this area. This article proposes six possible benchmarks for intellectual property-related challenges with regard to the development of medicines and ensuring access to medicines in developing countries.

  4. African schistosomiasis in mainland China: risk of transmission and countermeasures to tackle the risk

    PubMed Central

    2013-01-01

    Schistosomiasis is a major disease of public health importance in humans occurring in 76 countries of the tropics and sub-tropics. In China, schistosomiasis japonica is one of the highest priorities in communicable disease control defined by the central government. Since 1970s, the habitats of Biomphalaria straminea, an intermediate host of Schistosoma mansoni in South America, have been identified in Hong Kong Special Administrative Region and Shenzhen city, Guangdong province of China. With the sharp growth in the China-aided projects in Africa and labor services export to Africa, a gradual rise in the cases infected with S. haematobium or S. mansoni is reported in those returning from Africa to China. The existence of intermediate snail hosts and import of infectious source of schistosomiasis results in concern about the transmission of African schistosomiasis in mainland China in the context of global climate change. This paper evaluates the risk of transmission of African schistosomiasis in China, and proposes countermeasures and research priorities to tackle the risk. PMID:23985040

  5. Motor Matters: Tackling Heterogeneity of Parkinson’s Disease in Functional MRI Studies

    PubMed Central

    Möller, Harald E.; Sieger, Tomáš; Schroeter, Matthias L.; Vymazal, Josef; Růžička, Evžen; Jech, Robert

    2013-01-01

    To tackle the heterogeneity of Parkinson’s disease symptoms, most functional imaging studies tend to select a uniform group of subjects. We hypothesize that more profound considerations are needed to account for intra/inter-subject clinical variability and possibly for differing pathophysiological processes. Twelve patients were investigated using functional magnetic resonance imaging during visually-guided finger tapping. To account for disease heterogeneity, the motor score and individual symptom scores from the Unified Parkinson’s Disease Rating Scale (UPDRS-III) were utilized in the group-level model using two approaches either as the explanatory variable or as the effect of interest. Employment of the UPDRS-III score and symptom scores was systematically tested on the resulting group response to the levodopa challenge, which further accentuated the diversity of the diseased state of participants. Statistics revealed a bilateral group response to levodopa in the basal ganglia. Interestingly, systematic incorporation of individual motor aspects of the disease in the modelling amended the resulting activity patterns conspicuously, evidencing a manifold amount of explained variability by the particular score. In conclusion, the severity of clinical symptoms expressed in the UPDRS-III scores should be considered in the analysis to attain unbiased statistics, draw reliable conclusions and allow for comparisons between research groups studying Parkinson’s disease using functional magnetic resonance imaging. PMID:23418522

  6. Benchmarking progress in tackling the challenges of intellectual property, and access to medicines in developing countries.

    PubMed Central

    Musungu, Sisule F.

    2006-01-01

    The impact of intellectual property protection in the pharmaceutical sector on developing countries has been a central issue in the fierce debate during the past 10 years in a number of international fora, particularly the World Trade Organization (WTO) and WHO. The debate centres on whether the intellectual property system is: (1) providing sufficient incentives for research and development into medicines for diseases that disproportionately affect developing countries; and (2) restricting access to existing medicines for these countries. The Doha Declaration was adopted at WTO in 2001 and the Commission on Intellectual Property, Innovation and Public Health was established at WHO in 2004, but their respective contributions to tackling intellectual property-related challenges are disputed. Objective parameters are needed to measure whether a particular series of actions, events, decisions or processes contribute to progress in this area. This article proposes six possible benchmarks for intellectual property-related challenges with regard to the development of medicines and ensuring access to medicines in developing countries. PMID:16710545

  7. How will a life course framework be used to tackle wider social determinants of health?

    PubMed

    Nicolau, Belinda; Marcenes, Wagner

    2012-10-01

    The life course framework, proposed by Kuh and Schlomo in 1997, offers policy makers the means to understand the interaction between nature and nurture. This conceptual model illustrates how an individual's biological resources are influenced by their genetic endowment, their prenatal and postnatal development and their social and physical environment, both in early life and throughout the life course. Health is conceptualized as a dynamic process connecting biological and social elements that are affected by previous experiences and by present circumstances. Therefore, exposure at different stages of people's lives can either enhance or deplete the individual's health resources. Indeed, life course processes are of many kinds, including parent-child relationships, levels of social deprivation, the acquisition of emotional and behavioural assets in adolescence and the long-term effects of occupational hazards and work stress. The long-term effects of nature and nurture combine to influence disease outcomes. It is only in the last decade that theories, methods and new data have begun to be amalgamated, allowing us to further our understanding of health over the life course in ways that may eventually lead to more effective health policies and better health care. This article discusses life course concepts and how this framework can enlighten our understanding of wider social determinants of health, and provides a few examples of potential interventions to tackle their impact on health.

  8. Program effectiveness of a Restorative Whole-school Approach for tackling school bullying in Hong Kong.

    PubMed

    Wong, Dennis S W; Cheng, Christopher H K; Ngan, Raymond M H; Ma, Stephen K

    2011-09-01

    With bullying in schools high on policy makers' agendas, researchers are looking for effective strategies to tackle its disruptive effects. The present study sets out to address this issue. First, the prevalence of bullying is examined in Hong Kong High Schools, and second, the effectiveness of a Restorative Whole-school Approach (RWsA) in reducing bullying is examined in a quasi-experimental design. The RWsA emphasizes the setting up of restorative goals, clear instructions, team building, and good relationships among students, parents, and teachers. Over the course of 2 years, and across four schools, the effectiveness of this program was observed by comparing an intervention group with a partial intervention group (which did not receive the full treatment) and a control group (which received no treatment whatsoever). The group that received the RWsA treatment exhibited a significant reduction of bullying, higher empathic attitudes, and higher self-esteem in comparison to the partial intervention and the control group.

  9. [Social and organizational innovation to tackle the challenge of integrated care of the chronically ill].

    PubMed

    Nuño-Solinís, Roberto

    2014-01-01

    The increase in life expectancy, coupled with other factors, has led to an increase in the prevalence of chronic diseases and multiple morbidity. This has led to the need to develop new health and social care models, which will allow managing these efficiently and in a sustainable manner. In particular, there seems to be consensus on the need to move towards integrated, patient-centered, and more proactive care. Thus, in recent years, chronic care models have been developed at international, national and regional level, as well as introducing strategies to tackle the challenge of chronic illness. However, the implementation of actions facilitating the change towards this new model of care does not seem to be an easy task. This paper presents some of the strategic lines and initiatives carried out by the Department of Health of the Basque Government. These actions can be described within a social and organizational innovation framework, as a means for effective implementation of interventions and strategies that shape the model required for the improved care of chronic illnesses within a universal and tax-funded health system.

  10. Tackling missing data in community health studies using additive LS-SVM classifier.

    PubMed

    Wang, Guanjin; Deng, Zhaohong; Choi, Kup-Sze

    2016-12-01

    Missing data is a common issue in community health and epidemiological studies. Direct removal of samples with missing data can lead to reduced sample size and information bias, which deteriorates the significance of the results. While data imputation methods are available to deal with missing data, they are limited in performance and could introduce noises into the dataset. Instead of data imputation, a novel method based on additive least square support vector machine (LS-SVM) is proposed in this paper for predictive modeling when the input features of the model contain missing data. The method also determines simultaneously the influence of the features with missing values on the classification accuracy using the fast leave-one-out cross-validation strategy. The performance of the method is evaluated by applying it to predict the quality of life (QOL) of elderly people using health data collected in the community. The dataset involves demographics, socioeconomic status, health history and the outcomes of health assessments of 444 community-dwelling elderly people, with 5% to 60% of data missing in some of the input features. The QOL is measured using a standard questionnaire of the World Health Organization. Results show that the proposed method outperforms four conventional methods for handling missing data - case deletion, feature deletion, mean imputation and K-nearest neighbor imputation, with the average QOL prediction accuracy reaching 0.7418. It is potentially a promising technique for tackling missing data in community health research and other applications.

  11. Serious game development as a strategy for health promotion and tackling childhood obesity 1

    PubMed Central

    Dias, Jéssica David; Mekaro, Marcelo Shinyu; Cheng Lu, Jennifer Kaon; Otsuka, Joice Lee; Fonseca, Luciana Mara Monti; Zem-Mascarenhas, Silvia Helena

    2016-01-01

    ABSTRACT Objectives: to develop and assess a serious game on healthy eating and physical activity to promote health and tackle childhood obesity. Method: a descriptive, applied and methodological study.For the development of the game, the following steps were taken: conceptualization, pre-production with the development of the game documentation, prototyping, production and assessment of thecomputer and health experts. Results: a prototype has been developed up to beta version. The game was positively assessed both in terms of gameplay and mechanics, and in relation to the content presented, standing out as a powerful strategy for health promotion. The information from the assessment phase contributed to the settings in the software in order to make it available in the future for the target population of this research. The greatest advantage of the proposed game is the fact that it is an open educational resource. Conclusions: the expert assessments showed that the game has great educational potential and it is considered suitable for future application to the target audience.The serious game can become a technological teaching resource available for use in schools and health facilities, and can also be reused for the production of other educational games by accessing its source code. PMID:27533268

  12. 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

  13. 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.

  14. Synthesis and review: Tackling the nitrogen management challenge: from global to local scales

    NASA Astrophysics Data System (ADS)

    Reis, Stefan; Bekunda, Mateete; Howard, Clare M.; Karanja, Nancy; Winiwarter, Wilfried; Yan, Xiaoyuan; Bleeker, Albert; Sutton, Mark A.

    2016-12-01

    ) and the identification of policy and technology solutions to tackle global nitrogen management issues (IV), this will enable countries to fulfil their regional and global commitments.

  15. Tackling the stacking disorder of melon--structure elucidation in a semicrystalline material.

    PubMed

    Seyfarth, Lena; Seyfarth, Jan; Lotsch, Bettina V; Schnick, Wolfgang; Senker, Jürgen

    2010-03-07

    In this work we tackle the stacking disorder of melon, a layered carbon imide amide polymer with the ideal composition (C(6)N(7)(NH)(NH(2))). Although its existence has been postulated since 1834 the structure of individual melon layers could only recently be solved via electron diffraction and high-resolution (15)N solid-state NMR spectroscopy. With only weak van der Waals interactions between neighboring layers its long range stacking order is poorly defined preventing an efficient use of diffraction techniques. We, therefore, rely on a combination of solid-state NMR experiments and force field calculations. The key information is obtained based on heteronuclear ((1)H-(13)C) and homonuclear ((1)H-(1)H) second moments M(2) acquired from (1)H-(13)C cross polarization experiments. To allow for an interpretation of the polarization transfer rates the resonances in the (13)C MAS spectra have to be assigned and the hydrogen atoms have to be located. The assignment was performed using a two-dimensional (15)N-(13)C iDCP experiment. For the determination of the position of the hydrogen atoms NH and HH distances were measured via(1)H-(15)N Lee-Goldburg CP and (1)H-(1)H double-quantum build-up curves, respectively. Furthermore, the homogeneity of the material under examination was investigated exploiting (15)N spin-diffusion. Based on force field methods 256 structure models with varying lateral arrangements between neighboring layers were created. For each model the M(2) were calculated allowing them to be ranked by comparing calculated and measured M(2) as well as via their force field energies. This allows the creation of markedly structured hypersurfaces with two distinctly favored shift vectors for the displacement of neighboring layers.

  16. Tackling saponin diversity in marine animals by mass spectrometry: data acquisition and integration.

    PubMed

    Decroo, Corentin; Colson, Emmanuel; Demeyer, Marie; Lemaur, Vincent; Caulier, Guillaume; Eeckhaut, Igor; Cornil, Jérôme; Flammang, Patrick; Gerbaux, Pascal

    2017-03-01

    Saponin analysis by mass spectrometry methods is nowadays progressively supplementing other analytical methods such as nuclear magnetic resonance (NMR). Indeed, saponin extracts from plant or marine animals are often constituted by a complex mixture of (slightly) different saponin molecules that requires extensive purification and separation steps to meet the requirement for NMR spectroscopy measurements. Based on its intrinsic features, mass spectrometry represents an inescapable tool to access the structures of saponins within extracts by using LC-MS, MALDI-MS, and tandem mass spectrometry experiments. The combination of different MS methods nowadays allows for a nice description of saponin structures, without extensive purification. However, the structural characterization process is based on low kinetic energy CID which cannot afford a total structure elucidation as far as stereochemistry is concerned. Moreover, the structural difference between saponins in a same extract is often so small that coelution upon LC-MS analysis is unavoidable, rendering the isomeric distinction and characterization by CID challenging or impossible. In the present paper, we introduce ion mobility in combination with liquid chromatography to better tackle the structural complexity of saponin congeners. When analyzing saponin extracts with MS-based methods, handling the data remains problematic for the comprehensive report of the results, but also for their efficient comparison. We here introduce an original schematic representation using sector diagrams that are constructed from mass spectrometry data. We strongly believe that the proposed data integration could be useful for data interpretation since it allows for a direct and fast comparison, both in terms of composition and relative proportion of the saponin contents in different extracts. Graphical Abstract A combination of state-of-the-art mass spectrometry methods, including ion mobility spectroscopy, is developed to afford a

  17. Tackling community integration in mental health home visit integration in Finland.

    PubMed

    Raitakari, Suvi; Haahtela, Riikka; Juhila, Kirsi

    2016-09-01

    Integration - and its synonym inclusion - is emphasised in the western welfare states and in the European Union in particular. Integration is also a central topic in the social sciences and in current mental health and homelessness research and practice. As mental healthcare has shifted from psychiatric hospitals to the community, it has inevitably become involved with housing and integration issues. This article explores how community integration is understood and tackled in mental health floating support services (FSSs) and, more precisely, in service user-practitioner home visit interaction. The aim, through shedding light on how the idea of integration is present and discussed in front-line mental health practices, is to offer a 'template' on how we might, in a systematic and reflective way, develop community integration research and practice. The analysis is based on ethnomethodological and micro-sociological interaction research. The research settings are two FSSs located in a large Finnish city. The data contain 24 audio-recorded and transcribed home visits conducted in 2011 and 2012 with 16 different service users. The study shows how the participants in service user-practitioner interaction give meaning to community integration and make decisions about how it should (or should not) be enhanced in each individual case. This activity is called community integration work in action. Community integration work in action is based on various dimensions of integration: getting out of the house, participating in group activities and getting along with those involved in one's life and working life. Additionally, the analysis demonstrates how community integration work is accomplished by discursive devices (resistance, positioning, excuses and justifications, delicacy and advice-giving). The article concludes that community integration is about interaction: it is not only service users' individual challenge but also a social challenge, our challenge.

  18. Tackling NCD in LMIC: Achievements and Lessons Learned From the NHLBI-UnitedHealth Global Health Centers of Excellence Program.

    PubMed

    Engelgau, Michael M; Sampson, Uchechukwu K; Rabadan-Diehl, Cristina; Smith, Richard; Miranda, Jaime; Bloomfield, Gerald S; Belis, Deshiree; Narayan, K M Venkat

    2016-03-01

    Effectively tackling the growing noncommunicable disease (NCD) burden in low- and middle-income countries (LMIC) is a major challenge. To address research needs in this setting for NCDs, in 2009, National Heart, Lung, and Blood Institute (NHLBI) and UnitedHealth Group (UHG) engaged in a public-private partnership that supported a network of 11 LMIC-based research centers and created the NHLBI-UnitedHealth Global Health Centers of Excellence (COE) Program. The Program's overall goal was to contribute to reducing the cardiovascular and lung disease burdens by catalyzing in-country research institutions to develop a global network of biomedical research centers. Key elements of the Program included team science and collaborative approaches, developing research and training platforms for future investigators, and creating a data commons. This Program embraced a strategic approach for tackling NCDs in LMICs and will provide capacity for locally driven research efforts that can identify and address priority health issues in specific countries' settings.

  19. 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

  20. Microbial Community Responses to Glycine Addition in Kansas Prairie Soils

    NASA Astrophysics Data System (ADS)

    Bottos, E.; Roy Chowdhury, T.; White, R. A., III; Brislawn, C.; Fansler, S.; Kim, Y. M.; Metz, T. O.; McCue, L. A.; Jansson, J.

    2015-12-01

    Advances in sequencing technologies are rapidly expanding our abilities to unravel aspects of microbial community structure and function in complex systems like soil; however, characterizing the highly diverse communities is problematic, due primarily to challenges in data analysis. To tackle this problem, we aimed to constrain the microbial diversity in a soil by enriching for particular functional groups within a community through addition of "trigger substrates". Such trigger substrates, characterized by low molecular weight, readily soluble and diffusible in soil solution, representative of soil organic matter derivatives, would also be rapidly degradable. A relatively small energy investment to maintain the cell in a state of metabolic alertness for such substrates would be a better evolutionary strategy and presumably select for a cohort of microorganisms with the energetics and cellular machinery for utilization and growth. We chose glycine, a free amino acid (AA) known to have short turnover times (in the range of hours) in soil. As such, AAs are a good source of nitrogen and easily degradable, and can serve as building blocks for microbial proteins and other biomass components. We hypothesized that the addition of glycine as a trigger substrate will decrease microbial diversity and evenness, as taxa capable of metabolizing it are enriched in relation to those that are not. We tested this hypothesis by incubating three Kansas native prairie soils with glycine for 24 hours at 21 degree Celsius, and measured community level responses by 16S rRNA gene sequencing, metagenomics, and metatranscriptomics. Preliminary evaluation of 16S rRNA gene sequences revealed minor changes in bacterial community composition in response to glycine addition. We will also present data on functional gene abundance and expression. The results of these analyses will be useful in designing sequencing strategies aimed at dissecting and deciphering complex microbial communities.

  1. Systems-based approaches to unravel multi-species microbial community functioning

    PubMed Central

    Abram, Florence

    2014-01-01

    Some of the most transformative discoveries promising to enable the resolution of this century's grand societal challenges will most likely arise from environmental science and particularly environmental microbiology and biotechnology. Understanding how microbes interact in situ, and how microbial communities respond to environmental changes remains an enormous challenge for science. Systems biology offers a powerful experimental strategy to tackle the exciting task of deciphering microbial interactions. In this framework, entire microbial communities are considered as metaorganisms and each level of biological information (DNA, RNA, proteins and metabolites) is investigated along with in situ environmental characteristics. In this way, systems biology can help unravel the interactions between the different parts of an ecosystem ultimately responsible for its emergent properties. Indeed each level of biological information provides a different level of characterisation of the microbial communities. Metagenomics, metatranscriptomics, metaproteomics, metabolomics and SIP-omics can be employed to investigate collectively microbial community structure, potential, function, activity and interactions. Omics approaches are enabled by high-throughput 21st century technologies and this review will discuss how their implementation has revolutionised our understanding of microbial communities. PMID:25750697

  2. The Role of Labour Inspectorates in Tackling the Psychosocial Risks at Work in Europe: Problems and Perspectives.

    PubMed

    Toukas, Dimitrios; Delichas, Miltiadis; Toufekoula, Chryssoula; Spyrouli, Anastasia

    2015-12-01

    Significant changes in the past year have taken place in the world of work that are bringing new challenges with regard to employee safety and health. These changes have led to emerging psychosocial risks (PSRs) at work. The risks are primarily linked to how work is designed, organized, and managed, and to the economic and social frame of work. These factors have increased the level of work-related stress and can lead to serious deterioration in mental and physical health. In tackling PSRs, the European labor inspectorates can have an important role by enforcing preventive and/or corrective interventions in the content and context of work. However, to improve working conditions, unilateral interventions in the context and content of work are insufficient and require adopting a common strategy to tackle PSRs, based on a holistic approach. The implementation of a common strategy by the European Labor Inspectorate for tackling PSRs is restricted by the lack of a common legislative frame with regard to PSR evaluation and management, the different levels of labor inspectors' training, and the different levels of employees' and employers' health and safety culture.

  3. The Role of Labour Inspectorates in Tackling the Psychosocial Risks at Work in Europe: Problems and Perspectives

    PubMed Central

    Toukas, Dimitrios; Delichas, Miltiadis; Toufekoula, Chryssoula; Spyrouli, Anastasia

    2015-01-01

    Significant changes in the past year have taken place in the world of work that are bringing new challenges with regard to employee safety and health. These changes have led to emerging psychosocial risks (PSRs) at work. The risks are primarily linked to how work is designed, organized, and managed, and to the economic and social frame of work. These factors have increased the level of work-related stress and can lead to serious deterioration in mental and physical health. In tackling PSRs, the European labor inspectorates can have an important role by enforcing preventive and/or corrective interventions in the content and context of work. However, to improve working conditions, unilateral interventions in the context and content of work are insufficient and require adopting a common strategy to tackle PSRs, based on a holistic approach. The implementation of a common strategy by the European Labor Inspectorate for tackling PSRs is restricted by the lack of a common legislative frame with regard to PSR evaluation and management, the different levels of labor inspectors' training, and the different levels of employees' and employers' health and safety culture. PMID:26929837

  4. 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.

  5. 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...

  6. Tackling student neurophobia in neurosciences block with team-based learning

    PubMed Central

    Anwar, Khurshid; Shaikh, Abdul A.; Sajid, Muhammad R.; Cahusac, Peter; Alarifi, Norah A.; Al Shedoukhy, Ahlam

    2015-01-01

    improvement in communication and interpersonal skills. Conclusion We conclude that implementing TBL strategy increased students’ responsibility for their own learning and helped the students in bridging the gap in their cognitive knowledge to tackle ‘neurophobia’ in a difficult neurosciences block evidenced by their improved performance in the summative assessment. PMID:26232115

  7. Tackling student neurophobia in neurosciences block with team-based learning.

    PubMed

    Anwar, Khurshid; Shaikh, Abdul A; Sajid, Muhammad R; Cahusac, Peter; Alarifi, Norah A; Al Shedoukhy, Ahlam

    2015-01-01

    improvement in communication and interpersonal skills. Conclusion We conclude that implementing TBL strategy increased students' responsibility for their own learning and helped the students in bridging the gap in their cognitive knowledge to tackle 'neurophobia' in a difficult neurosciences block evidenced by their improved performance in the summative assessment.

  8. 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

  9. The combined water system as approach for tackling water scarcity in Permilovo groundwater basin

    NASA Astrophysics Data System (ADS)

    Filimonova, Elena; Baldenkov, Mikhail

    2014-05-01

    groundwater basin (PGB) was developed to illustrate the application of CWS. PGB is located in northwest of the Northern Dvina Artesian Basin, Russia. The principle aquifer is in the Carboniferous fissured and karstified rocks. The aquifer has a good hydraulic connection to the stream. The basin was explored but not used due to impermissible stream depletion. The organization of CWS is offered as approach for tackling environmental problem. The major well is located on the bank of river Vaymuga and induces infiltration from the stream. The deficiency of the stream flow in dry seasons (from November to April) is compensated for by the pumping aquifer storage. The aquifer system under consideration belongs to the first hydraulic case (a), where distance between CW and the stream should be sufficient enough to prevent the groundwater drawdown levels from reaching the stream edge during the pumping period. The developed PGB model showed the efficiency of compensation pumping. Application of the combined water system in PGB allows of meet water demands during water-limited periods and of avoid the environmental problems.

  10. 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.

  11. 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.

  12. Does a SLAP lesion affect shoulder muscle recruitment as measured by EMG activity during a rugby tackle?

    PubMed Central

    2010-01-01

    Background The study objective was to assess the influence of a SLAP lesion on onset of EMG activity in shoulder muscles during a front on rugby football tackle within professional rugby players. Methods Mixed cross-sectional study evaluating between and within group differences in EMG onset times. Testing was carried out within the physiotherapy department of a university sports medicine clinic. The test group consisted of 7 players with clinically diagnosed SLAP lesions, later verified on arthroscopy. The reference group consisted of 15 uninjured and full time professional rugby players from within the same playing squad. Controlled tackles were performed against a tackle dummy. Onset of EMG activity was assessed from surface EMG of Pectorialis Major, Biceps Brachii, Latissimus Dorsi, Serratus Anterior and Infraspinatus muscles relative to time of impact. Analysis of differences in activation timing between muscles and limbs (injured versus non-injured side and non injured side versus matched reference group). Results Serratus Anterior was activated prior to all other muscles in all (P = 0.001-0.03) subjects. In the SLAP injured shoulder Biceps was activated later than in the non-injured side. Onset times of all muscles of the non-injured shoulder in the injured player were consistently earlier compared with the reference group. Whereas, within the injured shoulder, all muscle activation timings were later than in the reference group. Conclusions This study shows that in shoulders with a SLAP lesion there is a trend towards delay in activation time of Biceps and other muscles with the exception of an associated earlier onset of activation of Serratus anterior, possibly due to a coping strategy to protect glenohumeral stability and thoraco-scapular stability. This trend was not statistically significant in all cases PMID:20184752

  13. 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

  14. Tackling U.S. energy challenges and opportunities: preliminary policy recommendations for enhancing energy innovation in the United States

    SciTech Connect

    Anadon, Laura Diaz; Gallagher, Kelly Sims; Bunn, Matthew; Jones, Charles

    2009-02-18

    The report offers preliminary recommendations for near-term actions to strengthen the U.S. effort to develop and deploy advanced energy technologies. The report comes as the Obama Administration and the 111th U.S. Congress face enormous challenges and opportunities in tackling the pressing security, economic, and environmental problems posed by the energy sector. Improving the technologies of energy supply and end-use is a prerequisite for surmounting these challenges in a timely and cost-effective way, and this report elaborates on how policy can support develop of these important energy technologies.

  15. Exploring the under-investigated "microbial dark matter" of drinking water treatment plants.

    PubMed

    Bruno, Antonia; Sandionigi, Anna; Rizzi, Ermanno; Bernasconi, Marzia; Vicario, Saverio; Galimberti, Andrea; Cocuzza, Clementina; Labra, Massimo; Casiraghi, Maurizio

    2017-03-14

    Scientists recently reported the unexpected detection of unknown or poorly studied bacterial diversity in groundwater. The ability to uncover this neglected biodiversity mainly derives from technical improvements, and the term "microbial dark matter" was used to group taxa poorly investigated and not necessarily monophyletic. We focused on such under-investigated microbial dark matter of drinking water treatment plant from groundwater, across carbon filters, to post-chlorination. We tackled this topic using an integrated approach where the efficacy of stringent water filtration (10000 MWCO) in recovering even the smallest environmental microorganisms was coupled with high-throughput DNA sequencing to depict an informative spectrum of the neglected microbial diversity. Our results revealed that the composition of bacterial communities varies across the plant system: Parcubacteria (OD1) superphylum is found mainly in treated water, while groundwater has the highest heterogeneity, encompassing non-OD1 candidate phyla (Microgenomates, Saccharibacteria, Dependentiae, OP3, OP1, BRC1, WS3). Carbon filters probably act as substrate for microorganism growth and contribute to seeding water downstream, since chlorination does not modify the incoming bacterial community. New questions arise about the role of microbial dark matter in drinking water. Indeed, our results suggest that these bacteria might play a central role in the microbial dynamics of drinking water.

  16. Exploring the under-investigated “microbial dark matter” of drinking water treatment plants

    PubMed Central

    Bruno, Antonia; Sandionigi, Anna; Rizzi, Ermanno; Bernasconi, Marzia; Vicario, Saverio; Galimberti, Andrea; Cocuzza, Clementina; Labra, Massimo; Casiraghi, Maurizio

    2017-01-01

    Scientists recently reported the unexpected detection of unknown or poorly studied bacterial diversity in groundwater. The ability to uncover this neglected biodiversity mainly derives from technical improvements, and the term “microbial dark matter” was used to group taxa poorly investigated and not necessarily monophyletic. We focused on such under-investigated microbial dark matter of drinking water treatment plant from groundwater, across carbon filters, to post-chlorination. We tackled this topic using an integrated approach where the efficacy of stringent water filtration (10000 MWCO) in recovering even the smallest environmental microorganisms was coupled with high-throughput DNA sequencing to depict an informative spectrum of the neglected microbial diversity. Our results revealed that the composition of bacterial communities varies across the plant system: Parcubacteria (OD1) superphylum is found mainly in treated water, while groundwater has the highest heterogeneity, encompassing non-OD1 candidate phyla (Microgenomates, Saccharibacteria, Dependentiae, OP3, OP1, BRC1, WS3). Carbon filters probably act as substrate for microorganism growth and contribute to seeding water downstream, since chlorination does not modify the incoming bacterial community. New questions arise about the role of microbial dark matter in drinking water. Indeed, our results suggest that these bacteria might play a central role in the microbial dynamics of drinking water. PMID:28290543

  17. 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.

  18. 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....

  19. Tackling the minority: sulfate-reducing bacteria in an archaea-dominated subsurface biofilm.

    PubMed

    Probst, Alexander J; Holman, Hoi-Ying N; DeSantis, Todd Z; Andersen, Gary L; Birarda, Giovanni; Bechtel, Hans A; Piceno, Yvette M; Sonnleitner, Maria; Venkateswaran, Kasthuri; Moissl-Eichinger, Christine

    2013-03-01

    Archaea are usually minor components of a microbial community and dominated by a large and diverse bacterial population. In contrast, the SM1 Euryarchaeon dominates a sulfidic aquifer by forming subsurface biofilms that contain a very minor bacterial fraction (5%). These unique biofilms are delivered in high biomass to the spring outflow that provides an outstanding window to the subsurface. Despite previous attempts to understand its natural role, the metabolic capacities of the SM1 Euryarchaeon remain mysterious to date. In this study, we focused on the minor bacterial fraction in order to obtain insights into the ecological function of the biofilm. We link phylogenetic diversity information with the spatial distribution of chemical and metabolic compounds by combining three different state-of-the-art methods: PhyloChip G3 DNA microarray technology, fluorescence in situ hybridization (FISH) and synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectromicroscopy. The results of PhyloChip and FISH technologies provide evidence for selective enrichment of sulfate-reducing bacteria, which was confirmed by the detection of bacterial dissimilatory sulfite reductase subunit B (dsrB) genes via quantitative PCR and sequence-based analyses. We further established a differentiation of archaeal and bacterial cells by SR-FTIR based on typical lipid and carbohydrate signatures, which demonstrated a co-localization of organic sulfate, carbonated mineral and bacterial signatures in the biofilm. All these results strongly indicate an involvement of the SM1 euryarchaeal biofilm in the global cycles of sulfur and carbon and support the hypothesis that sulfidic springs are important habitats for Earth's energy cycles. Moreover, these investigations of a bacterial minority in an Archaea-dominated environment are a remarkable example of the great power of combining highly sensitive microarrays with label-free infrared imaging.

  20. Tackling the minority: sulfate-reducing bacteria in an archaea-dominated subsurface biofilm

    PubMed Central

    Probst, Alexander J; Holman, Hoi-Ying N; DeSantis, Todd Z; Andersen, Gary L; Birarda, Giovanni; Bechtel, Hans A; Piceno, Yvette M; Sonnleitner, Maria; Venkateswaran, Kasthuri; Moissl-Eichinger, Christine

    2013-01-01

    Archaea are usually minor components of a microbial community and dominated by a large and diverse bacterial population. In contrast, the SM1 Euryarchaeon dominates a sulfidic aquifer by forming subsurface biofilms that contain a very minor bacterial fraction (5%). These unique biofilms are delivered in high biomass to the spring outflow that provides an outstanding window to the subsurface. Despite previous attempts to understand its natural role, the metabolic capacities of the SM1 Euryarchaeon remain mysterious to date. In this study, we focused on the minor bacterial fraction in order to obtain insights into the ecological function of the biofilm. We link phylogenetic diversity information with the spatial distribution of chemical and metabolic compounds by combining three different state-of-the-art methods: PhyloChip G3 DNA microarray technology, fluorescence in situ hybridization (FISH) and synchrotron radiation-based Fourier transform infrared (SR-FTIR) spectromicroscopy. The results of PhyloChip and FISH technologies provide evidence for selective enrichment of sulfate-reducing bacteria, which was confirmed by the detection of bacterial dissimilatory sulfite reductase subunit B (dsrB) genes via quantitative PCR and sequence-based analyses. We further established a differentiation of archaeal and bacterial cells by SR-FTIR based on typical lipid and carbohydrate signatures, which demonstrated a co-localization of organic sulfate, carbonated mineral and bacterial signatures in the biofilm. All these results strongly indicate an involvement of the SM1 euryarchaeal biofilm in the global cycles of sulfur and carbon and support the hypothesis that sulfidic springs are important habitats for Earth's energy cycles. Moreover, these investigations of a bacterial minority in an Archaea-dominated environment are a remarkable example of the great power of combining highly sensitive microarrays with label-free infrared imaging. PMID:23178669

  1. 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

  2. Tackling the social determinants of inequalities in health during Phase V of the Healthy Cities Project in Europe.

    PubMed

    Ritsatakis, Anna; Ostergren, Per-Olof; Webster, Premila

    2015-06-01

    The WHO European Healthy Cities Network has from its inception aimed at tackling inequalities in health. In carrying out an evaluation of Phase V of the project (2009-13), an attempt was made to examine how far the concept of equity in health is understood and accepted; whether cities had moved further from a disease/medical model to looking at the social determinants of inequalities in health; how far the HC project contributed to cities determining the extent and causes of inequalities in health; what efforts were made to tackle such inequalities and how far inequalities in health may have increased or decreased during Phase V. A broader range of resources was utilized for this evaluation than in previous phases of the project. These indicated that most cities were definitely looking at the broader determinants. Equality in health was better understood and had been included as a value in a range of city policies. This was facilitated by stronger involvement of the HC project in city planning processes. Although almost half the cities participating had prepared a City Health Profile, only few cities had the necessary local level data to monitor changes in inequalities in health.

  3. How to Tackle Key Challenges in the Promotion of Physical Activity among Older Adults (65+): The AEQUIPA Network Approach.

    PubMed

    Forberger, Sarah; Bammann, Karin; Bauer, Jürgen; Boll, Susanne; Bolte, Gabriele; Brand, Tilman; Hein, Andreas; Koppelin, Frauke; Lippke, Sonia; Meyer, Jochen; Pischke, Claudia R; Voelcker-Rehage, Claudia; Zeeb, Hajo

    2017-04-04

    The paper introduces the theoretical framework and methods/instruments used by the Physical Activity and Health Equity: Primary Prevention for Healthy Ageing (AEQUIPA) prevention research network as an interdisciplinary approach to tackle key challenges in the promotion of physical activity among older people (65+). Drawing on the social-ecological model, the AEQUIPA network developed an interdisciplinary methodological design including quantitative/qualitative studies and systematic reviews, while combining expertise from diverse fields: public health, psychology, urban planning, sports sciences, health technology and geriatrics. AEQUIPA tackles key challenges when promoting physical activity (PA) in older adults: tailoring of interventions, fostering community readiness and participation, strengthening intersectoral collaboration, using new technological devices and evaluating intervention generated inequalities. AEQUIPA aims to strengthen the evidence base for age-specific preventive PA interventions and to yield new insights into the explanatory power of individual and contextual factors. Currently, the empirical work is still underway. First experiences indicate that thenetwork has achieved a strong regional linkage with communities, local stakeholders and individuals. However, involving inactive persons and individuals from minority groups remained challenging. A review of existing PA intervention studies among the elderly revealed the potential to assess equity effects. The results will add to the theoretical and methodological discussion on evidence-based age-specific PA interventions and will contribute to the discussion about European and national health targets.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. 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 ...

  10. 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)

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. Tackling the Challenge of Deep Vadose Zone Remediation at the Hanford Site

    NASA Astrophysics Data System (ADS)

    Morse, J. G.; Wellman, D. M.; Gephart, R.

    2010-12-01

    The Central Plateau of the Hanford Site in Washington State contains some 800 waste disposal sites where 1.7 trillion liters of contaminated water was once discharged into the subsurface. Most of these sites received liquids from the chemical reprocessing of spent uranium fuel to recover plutonium. In addition, 67 single shell tanks have leaked or are suspected to have leaked 3.8 million liters of high alkali and aluminate rich cesium-contaminated liquids into the sediment. Today, this inventory of subsurface contamination contains an estimated 550,000 curies of radioactivity and 150 million kg (165,000 tons) of metals and hazardous chemicals. Radionuclides range from mobile 99Tc to more immobilized 137Cs, 241Am, uranium, and plutonium. A significant fraction of these contaminants likely remain within the deep vadose zone. Plumes of groundwater containing tritium, nitrate, 129I and other contaminants have migrated through the vadose zone and now extend outward from the Central Plateau to the Columbia River. During most of Hanford Site history, subsurface studies focused on groundwater monitoring and characterization to support waste management decisions. Deep vadose zone studies were not a priority because waste practices relied upon that zone to buffer contaminant releases into the underlying aquifer. Remediation of the deep vadose zone is now central to Hanford Site cleanup because these sediments can provide an ongoing source of contamination to the aquifer and therefore to the Columbia River. However, characterization and remediation of the deep vadose zone pose some unique challenges. These include sediment thickness; contaminant depth; coupled geohydrologic, geochemical, and microbial processes controlling contaminant spread; limited availability and effectiveness of traditional characterization tools and cleanup remedies; and predicting contaminant behavior and remediation performance over long time periods and across molecular to field scales. The U

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  4. 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.

  5. An Ultrahydrophobic Fluorous Metal-Organic Framework Derived Recyclable Composite as a Promising Platform to Tackle Marine Oil Spills.

    PubMed

    Mukherjee, Soumya; Kansara, Ankit M; Saha, Debasis; Gonnade, Rajesh; Mullangi, Dinesh; Manna, Biplab; Desai, Aamod V; Thorat, Shridhar H; Singh, Puyam S; Mukherjee, Arnab; Ghosh, Sujit K

    2016-07-25

    Derived from a strategically chosen hexafluorinated dicarboxylate linker aimed at the designed synthesis of a superhydrophobic metal-organic framework (MOF), the fluorine-rich nanospace of a water-stable MOF (UHMOF-100) exhibits excellent water-repellent features. It registered the highest water contact angle (≈176°) in the MOF domain, marking the first example of an ultrahydrophobic MOF. Various experimental and theoretical studies reinforce its distinctive water-repellent characteristics, and the conjugation of superoleophilicity and unparalleled hydrophobicity of a MOF material has been coherently exploited to achieve real-time oil/water separation in recyclable membrane form, with significant absorption capacity performance. This is also the first report of an oil/water separating fluorinated ultrahydrophobic MOF-based membrane material, with potential promise for tackling marine oil spillages.

  6. Tackling the Use of Supari (Areca Nut) and Smokeless Tobacco Products in the South Asian Community in the United Kingdom.

    PubMed

    Chande, Milan; Suba, Krishna

    2016-06-01

    The use of supari (areca nut) and smokeless tobacco products are seen as a major risk factor for oral cancer. There are increasing rates of oral cancer across the United Kingdom, along with the increase of the use of these products. This article examines the uses of such products amongst the South Asian Community and explores sensitive issues associated with the cessation of their use. Evidence-based recommendations are provided on how to provide advice and treatment to patients that regularly use these products. A rethink is also suggested on the policy of taxation of such products. CPD/Clinical Relevance: With the rates of oral cancer increasing across the United Kingdom, it is important for us as dental professionals to tackle the use of areca nut and smokeless tobacco products.

  7. Tackling Millennium Development Goals (MDGs) 4 and 5: The National Health Insurance Scheme (NHIS) Approach in Nigeria

    PubMed Central

    Mohammed, Shafiu

    2012-01-01

    Developing countries are devising various strategies and mechanisms to accelerate their speed towards the Millennium Development Goals (MDGs) by 2015. In Nigeria, different approaches have been used to address the tackling of health-related MDGs. One creative approach has been the implementation of the NHIS Maternal and Child Health (NHIS-MCH) Project. The project aims to speed up the achievement of MDGs 4 and 5 (reducing child mortality and improving maternal health) in the country. Little is known about the NHIS-MCH Project’s design and health insurance coverage activities. Project planning and monitoring could be hampered by lack of technical and managerial skills of health insurance most especially at middle and local levels. Challenging debates continue to emanate on the project’s sustainability.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Study of Electrochemical Reduction of CO2 for Future Use in Secondary Microbial Electrochemical Technologies.

    PubMed

    Gimkiewicz, Carla; Hegner, Richard; Gutensohn, Mareike F; Koch, Christin; Harnisch, Falk

    2017-03-09

    The fluctuation and decentralization of renewable energy have triggered the search for respective energy storage and utilization. At the same time, a sustainable bioeconomy calls for the exploitation of CO2 as feedstock. Secondary microbial electrochemical technologies (METs) allow both challenges to be tackled because the electrochemical reduction of CO2 can be coupled with microbial synthesis. Because this combination creates special challenges, the electrochemical reduction of CO2 was investigated under conditions allowing microbial conversions, that is, for their future use in secondary METs. A reproducible electrodeposition procedure of In on a graphite backbone allowed a systematic study of formate production from CO2 with a high number of replicates. Coulomb efficiencies and formate production rates of up to 64.6±6.8 % and 0.013±0.002 mmolformate  h(-1)  cm(-2) , respectively, were achieved. Electrode redeposition, reusability, and long-term performance were investigated. Furthermore, the effect of components used in microbial media, that is, yeast extract, trace elements, and phosphate salts, on the electrode performance was addressed. The results demonstrate that the integration of electrochemical reduction of CO2 in secondary METs can become technologically relevant.

  15. Tackle-related injury rates and nature of injuries in South African Youth Week tournament rugby union players (under-13 to under-18): an observational cohort study

    PubMed Central

    Burger, Nicholas; Lambert, Mike I; Viljoen, Wayne; Brown, James C; Readhead, Clint; Hendricks, Sharief

    2014-01-01

    Objectives The tackle situation is most often associated with the high injury rates in rugby union. Tackle injury epidemiology in rugby union has previously been focused on senior cohorts but less is known about younger cohorts. The aim of this study was to report on the nature and rates of tackle-related injuries in South African youth rugby union players representing their provinces at national tournaments. Design Observational cohort study. Setting Four South African Youth Week tournaments (under-13 Craven Week, under-16 Grant Khomo Week, under-18 Academy Week, under-18 Craven Week). Participants Injury data were collected from 3652 youth rugby union players (population at risk) in 2011 and 2012. Outcome measures Tackle-related injury severity (‘time-loss’ and ‘medical attention’), type and location, injury rate per 1000 h (including 95% CIs). Injury rate ratios (IRR) were calculated and modelled using a Poisson regression. A χ2 analysis was used to detect linear trends between injuries and increasing match quarters. Results The 2012 under-13 Craven Week had a significantly greater ‘time-loss’ injury rate when compared with the 2012 under-18 Academy Week (IRR=4.43; 95% CI 2.13 to 9.21, p<0.05) and under-18 Craven Week (IRR=3.52; 95% CI 1.54 to 8.00, p<0.05). The Poisson regression also revealed a higher probability of ‘overall’ (‘time-loss’ and ‘medical attention’ combined) and ‘time-loss’ tackle-related injuries occurring at the under-13 Craven Week. The proportion of ‘overall’ and ‘time-loss’ injuries increased significantly with each quarter of the match when all four tournaments were combined (p<0.05). Conclusions There was a difference in the tackle-related injury rate between the under-13 tournament and the two under-18 tournaments, and the tackle-related injury rate was higher in the final quarter of matches. Ongoing injury surveillance is required to better interpret these findings. Injury prevention strategies

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. [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.

  1. 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.

  2. 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.

  3. 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.

  4. Tackling the STEM Crisis: Five Steps Your State Can Take to Improve the Quality and Quantity of its K-12 Math and Science Teachers

    ERIC Educational Resources Information Center

    National Council on Teacher Quality, 2009

    2009-01-01

    State laws and regulations can either help or hinder the ability of school districts to hire effective teachers for STEM (science, technology, engineering and mathematics) subjects. State officials wanting to tackle this critical problem need to begin with a thorough review of relevant policies, asking themselves: "Are we part of the problem, and…

  5. Which Women Were Executed for Witchcraft? And Which Pupils Cared? Low-Attaining Year 8 Use Fiction to Tackle Three Demons: Extended Reading, Diversity and Causation

    ERIC Educational Resources Information Center

    Worth, Paula

    2011-01-01

    Paula Worth was concerned that her low-attaining set were only going through the motions when tackling causal explanation. Identifying, prioritising and weighing causes seemed an empty routine rather than a fascinating puzzle engaging intellect and imagination. She was also concerned that her usual efforts to solve this problem had been misplaced.…

  6. 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.

  7. 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.

  8. 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...

  9. 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.

  10. 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)

  11. Histone deacetylase inhibitor pracinostat in doublet therapy: a unique strategy to improve therapeutic efficacy and to tackle herculean cancer chemoresistance.

    PubMed

    Ganai, Shabir Ahmad

    2016-09-01

    Context Histone deacetylase inhibitors (HDACi) have shown promising results in neurodegeneration and cancer. Hydroxamate HDACi, including vorinostat, have shown encouraging results in haematological malignancies, but the poor pharmacokinetic of these inhibitors leads to insufficient tumour concentration limiting their application against solid malignancies. Objective This article deals with novel HDAC inhibitor pracinostat (SB939) and delineates its therapeutic role in solid and haematological malignancies. The article provides rigorous details about the underlying molecular mechanisms modulated by pracinostat to exert cytotoxic effect. The article further highlights the doublet therapy that may be used to tackle monotonous cancer chemoresistance. Methods Both old and the latest literature on pracinostat was retrieved from diverse sources, such as PubMed, Science Direct, Springer Link, general Google search using both pracinostat and SB939 keywords in various ways: after thorough evaluation the topic which can fulfil the current gap was chosen. Results Pracinostat shows potent anticancer activity against both solid and haematological malignancies compared to the FDA-approved drug vorinostat. This marvellous inhibitor has better physicochemical, pharmaceutical and pharmacokinetic properties than the defined inhibitor vorinostat. Pracinostat has  >100-fold more affinity towards HDACs compared to other zinc-dependent metalloenzymes and shows maximum efficacy when used in doublet therapy. Conclusion Pracinostat shows potent anticancer activity even against therapeutically challenging cancers when used in doublet therapy. However, the triplet combination studies of the defined inhibitor that may prove even more beneficial are still undone, emphasizing the desperate need of further research in the defined gap.

  12. Recovery strategies for tackling the impact of phenolic compounds in a UASB reactor treating coal gasification wastewater.

    PubMed

    Wang, Wei; Han, Hongjun

    2012-01-01

    The impact of phenolic compounds (around 3.2 g/L) resulted in a completely failed performance in a mesophilic UASB reactor treating coal gasification wastewater. The recovery strategies, including extension of HRT, dilution, oxygen-limited aeration, and addition of powdered activated carbon were evaluated in batch tests, in order to obtain the most appropriate way for the quick recovery of the failed reactor performance. Results indicated that addition of powdered activated carbon and oxygen-limited aeration were the best recovery strategies in the batch tests. In the UASB reactor, addition of powdered activated carbon of 1 g/L shortened the recovery time from 25 to 9 days and oxygen-limited aeration of 0-0.5 mgO2/L reduced the recovery time to 17 days. Reduction of bioavailable concentration of phenolic compounds and recovery of sludge activity were the decisive factors for the recovery strategies to tackle the impact of phenolic compounds in anaerobic treatment of coal gasification wastewater.

  13. Responsibility without legal authority? Tackling alcohol-related health harms through licensing and planning policy in local government

    PubMed Central

    Martineau, F.P.; Graff, H.; Mitchell, C.; Lock, K.

    2014-01-01

    Background The power to influence many social determinants of health lies within local government sectors that are outside public health's traditional remit. We analyse the challenges of achieving health gains through local government alcohol control policies, where legal and professional practice frameworks appear to conflict with public health action. Methods Current legislation governing local alcohol control in England and Wales is reviewed and analysed for barriers and opportunities to implement effective population-level health interventions. Case studies of local government alcohol control practices are described. Results Addressing alcohol-related health harms is constrained by the absence of a specific legal health licensing objective and differences between public health and legal assessments of the relevance of health evidence to a specific place. Local governments can, however, implement health-relevant policies by developing local evidence for alcohol-related health harms; addressing cumulative impact in licensing policy statements and through other non-legislative approaches such as health and non-health sector partnerships. Innovative local initiatives—for example, minimum unit pricing licensing conditions—can serve as test cases for wider national implementation. Conclusions By combining the powers available to the many local government sectors involved in alcohol control, alcohol-related health and social harms can be tackled through existing local mechanisms. PMID:23933915

  14. Deliberative Mapping of options for tackling climate change: Citizens and specialists ‘open up’ appraisal of geoengineering

    PubMed Central

    Bellamy, Rob; Chilvers, Jason; Vaughan, Naomi E.

    2014-01-01

    Appraisals of deliberate, large-scale interventions in the earth’s climate system, known collectively as ‘geoengineering’, have largely taken the form of narrowly framed and exclusive expert analyses that prematurely ‘close down’ upon particular proposals. Here, we present the findings from the first ‘upstream’ appraisal of geoengineering to deliberately ‘open up’ to a broader diversity of framings, knowledges and future pathways. We report on the citizen strand of an innovative analytic–deliberative participatory appraisal process called Deliberative Mapping. A select but diverse group of sociodemographically representative citizens from Norfolk (United Kingdom) were engaged in a deliberative multi-criteria appraisal of geoengineering proposals relative to other options for tackling climate change, in parallel to symmetrical appraisals by diverse experts and stakeholders. Despite seeking to map divergent perspectives, a remarkably consistent view of option performance emerged across both the citizens’ and the specialists’ deliberations, where geoengineering proposals were outperformed by mitigation alternatives. PMID:25224904

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. Tackling Absenteeism in Chicago

    ERIC Educational Resources Information Center

    Allensworth, Elaine; Evans, Shayne

    2016-01-01

    Incisive research from the University of Chicago Urban Education Institute on the prevalence and consequences of absenteeism in Chicago schools has highlighted the dramatic effects of even moderate amounts of absences on grades, graduation rates, and student success in college. These insights spurred not only an ambitious 98% attendance goal on…

  3. Smith Tackles Oakland Unified

    ERIC Educational Resources Information Center

    Mellon, Ericka

    2011-01-01

    As a 20-something, Anthony "Tony" Smith had fulfilled one dream: playing professional football for the Green Bay Packers and the San Francisco 49ers. Next up, he thought, was law school, but a former mentor reminded him that he is a teacher. Smith never became a classroom teacher, but his background in sports--where he learned the power…

  4. Districts Tackling Meal Debt

    ERIC Educational Resources Information Center

    Shah, Nirvi

    2012-01-01

    School districts have resorted to hiring debt collectors, employing constables, and swapping out standard meals for scaled-back versions to try to coerce parents to pay off school lunch debt that, in recent years, appears to have surged as the result of a faltering economy and better record-keeping. While the average school lunch costs just about…

  5. Tackling the Sixth State

    ERIC Educational Resources Information Center

    Kolm, Henry H.

    1975-01-01

    Describes the process of high gradient magnetic separation which gives promise as a method of large scale removal of colloidal impurities including bacteria and viruses. Examples and diagrams are included. (GH)

  6. Tackling a Local Problem.

    ERIC Educational Resources Information Center

    Cook, Martin

    1995-01-01

    Students studying water as a class project were concerned by levels of pollution at a nearby river and the local beach. They identified three environmental problems for research including sewage discharge, beach litter, and quality of swimming water. Research consisted of field trips which allowed for opportunities to improve skills in collecting…

  7. Tackling Human Rights

    ERIC Educational Resources Information Center

    McLester, Susan

    2005-01-01

    In 2003, four high school students from the Tashkent International School in the capital city confronted the issue of their nation's human rights problems head on by researching the topic and publishing their findings on the Web. The site, "Uzbekistan: Opaque Reality," was created as an entry for the non-profit Global SchoolNet's Doors…

  8. Tackling conference carbon footprints

    NASA Astrophysics Data System (ADS)

    Grozier, Jim

    2016-12-01

    In reply to Margaret Harris's Lateral Thoughts article "Putting my foot down", which discussed the challenges of attending a conference with a physical disability (October p76) and a subsequent letter by Anna Wood (November p18).

  9. [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.

  10. Enhancing metaproteomics-The value of models and defined environmental microbial systems

    SciTech Connect

    Herbst, Florian-Alexander; Lünsmann, Vanessa; Kjeldal, Henrik; Jehmlich, Nico; Tholey, Andreas; von Bergen, Martin; Nielsen, Jeppe Lund; Hettich, Robert L.; Seifert, Jana; Nielsen, Per Halkjaer

    2016-01-21

    Metaproteomicsthe large-scale characterization of the entire protein complement of environmental microbiota at a given point in timehas provided new features to study complex microbial communities in order to unravel these black boxes. Some new technical challenges arose that were not an issue for classical proteome analytics before that could be tackled by the application of different model systems. Here, we review different current and future model systems for metaproteome analysis. We introduce model systems for clinical and biotechnological research questions including acid mine drainage, anaerobic digesters, and activated sludge, following a short introduction to microbial communities and metaproteomics. Model systems are useful to evaluate the challenges encountered within (but not limited to) metaproteomics, including species complexity and coverage, biomass availability, or reliable protein extraction. Moreover, the implementation of model systems can be considered as a step forward to better understand microbial community responses and ecological functions of single member organisms. In the future, improvements are necessary to fully explore complex environmental systems by metaproteomics.

  11. Enhancing metaproteomics-The value of models and defined environmental microbial systems

    DOE PAGES

    Herbst, Florian-Alexander; Lünsmann, Vanessa; Kjeldal, Henrik; ...

    2016-01-21

    Metaproteomicsthe large-scale characterization of the entire protein complement of environmental microbiota at a given point in timehas provided new features to study complex microbial communities in order to unravel these black boxes. Some new technical challenges arose that were not an issue for classical proteome analytics before that could be tackled by the application of different model systems. Here, we review different current and future model systems for metaproteome analysis. We introduce model systems for clinical and biotechnological research questions including acid mine drainage, anaerobic digesters, and activated sludge, following a short introduction to microbial communities and metaproteomics. Model systemsmore » are useful to evaluate the challenges encountered within (but not limited to) metaproteomics, including species complexity and coverage, biomass availability, or reliable protein extraction. Moreover, the implementation of model systems can be considered as a step forward to better understand microbial community responses and ecological functions of single member organisms. In the future, improvements are necessary to fully explore complex environmental systems by metaproteomics.« less

  12. Population-reaction model and microbial experimental ecosystems for understanding hierarchical dynamics of ecosystems.

    PubMed

    Hosoda, Kazufumi; Tsuda, Soichiro; Kadowaki, Kohmei; Nakamura, Yutaka; Nakano, Tadashi; Ishii, Kojiro

    2016-02-01

    Understanding ecosystem dynamics is crucial as contemporary human societies face ecosystem degradation. One of the challenges that needs to be recognized is the complex hierarchical dynamics. Conventional dynamic models in ecology often represent only the population level and have yet to include the dynamics of the sub-organism level, which makes an ecosystem a complex adaptive system that shows characteristic behaviors such as resilience and regime shifts. The neglect of the sub-organism level in the conventional dynamic models would be because integrating multiple hierarchical levels makes the models unnecessarily complex unless supporting experimental data are present. Now that large amounts of molecular and ecological data are increasingly accessible in microbial experimental ecosystems, it is worthwhile to tackle the questions of their complex hierarchical dynamics. Here, we propose an approach that combines microbial experimental ecosystems and a hierarchical dynamic model named population-reaction model. We present a simple microbial experimental ecosystem as an example and show how the system can be analyzed by a population-reaction model. We also show that population-reaction models can be applied to various ecological concepts, such as predator-prey interactions, climate change, evolution, and stability of diversity. Our approach will reveal a path to the general understanding of various ecosystems and organisms.

  13. What visual illusions tell us about underlying neural mechanisms and observer strategies for tackling the inverse problem of achromatic perception

    PubMed Central

    Blakeslee, Barbara; McCourt, Mark E.

    2015-01-01

    Research in lightness perception centers on understanding the prior assumptions and processing strategies the visual system uses to parse the retinal intensity distribution (the proximal stimulus) into the surface reflectance and illumination components of the scene (the distal stimulus—ground truth). It is agreed that the visual system must compare different regions of the visual image to solve this inverse problem; however, the nature of the comparisons and the mechanisms underlying them are topics of intense debate. Perceptual illusions are of value because they reveal important information about these visual processing mechanisms. We propose a framework for lightness research that resolves confusions and paradoxes in the literature, and provides insight into the mechanisms the visual system employs to tackle the inverse problem. The main idea is that much of the debate and confusion in the literature stems from the fact that lightness, defined as apparent reflectance, is underspecified and refers to three different types of judgments that are not comparable. Under stimulus conditions containing a visible illumination component, such as a shadow boundary, observers can distinguish and match three independent dimensions of achromatic experience: apparent intensity (brightness), apparent local intensity ratio (brightness-contrast), and apparent reflectance (lightness). In the absence of a visible illumination boundary, however, achromatic vision reduces to two dimensions and, depending on stimulus conditions and observer instructions, judgments of lightness are identical to judgments of brightness or brightness-contrast. Furthermore, because lightness judgments are based on different information under different conditions, they can differ greatly in their degree of difficulty and in their accuracy. This may, in part, explain the large variability in lightness constancy across studies. PMID:25954181

  14. Tackling reproducibility in microcantilever biosensors: a statistical approach for sensitive and specific end-point detection of immunoreactions.

    PubMed

    Kosaka, Priscila M; Tamayo, Javier; Ruz, José J; Puertas, Sara; Polo, Ester; Grazu, Valeria; de la Fuente, Jesús M; Calleja, Montserrat

    2013-02-21

    In the last decade, microcantilever biosensors have shown enormous potential for highly sensitive label-free detection of nucleic acid and proteins. Despite the enormous advances, the promise of applications of this technology in the biomedical field has been frustrated because of its low reproducibility. Here we tackle the reproducibility issue in microcantilever biosensors and provide the guidelines to minimize the deviations in the biosensor response between different assays. We use as a model system the label-free end-point detection of horseradish peroxidase. We choose the end-point detection mode because of its suitability for implementation in the clinical field that requires simplicity and point-of-care capability. Our study comprises the analysis of 1012 cantilevers with different antibody surface densities, two blocking strategies based on polyethylene-glycol (PEG) and bovine serum albumin (BSA) and stringent controls. The study reveals that the performance of the assay critically depends on both antibody surface density and blocking strategies. We find that the optimal conditions involve antibody surface densities near but below saturation and blocking with PEG. We find that the surface stress induced by the antibody-antigen binding is significantly correlated with the surface stress generated during the antibody attachment and blocking steps. The statistical correlation is harnessed to identify immobilization failure or success, and thus enhancing the specificity and sensitivity of the assay. This procedure enables achieving rates of true positives and true negatives of 90% and 91% respectively. The detection limit is of 10 ng mL(-1) (250 pM) that is similar to the detection limit obtained in our enzyme-linked immunosorbent assay (ELISA) and at least two orders of magnitude smaller than that achieved with well-established label-free biosensors such as a quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) sensor.

  15. Big data or bust: realizing the microbial genomics revolution

    PubMed Central

    Luheshi, Leila

    2016-01-01

    Pathogen genomics has the potential to transform the clinical and public health management of infectious diseases through improved diagnosis, detection and tracking of antimicrobial resistance and outbreak control. However, the wide-ranging benefits of this technology can only fully be realized through the timely collation, integration and sharing of genomic and clinical/epidemiological metadata by all those involved in the delivery of genomic-informed services. As part of our review on bringing pathogen genomics into ‘health-service’ practice, we undertook extensive stakeholder consultation to examine the factors integral to achieving effective data sharing and integration. Infrastructure tailored to the needs of clinical users, as well as practical support and policies to facilitate the timely and responsible sharing of data with relevant health authorities and beyond, are all essential. We propose a tiered data sharing and integration model to maximize the immediate and longer term utility of microbial genomics in healthcare. Realizing this model at the scale and sophistication necessary to support national and international infection management services is not uncomplicated. Yet the establishment of a clear data strategy is paramount if failures in containing disease spread due to inadequate knowledge sharing are to be averted, and substantial progress made in tackling the dangers posed by infectious diseases. PMID:28348842

  16. Big data or bust: realizing the microbial genomics revolution.

    PubMed

    Raza, Sobia; Luheshi, Leila

    2016-02-01

    Pathogen genomics has the potential to transform the clinical and public health management of infectious diseases through improved diagnosis, detection and tracking of antimicrobial resistance and outbreak control. However, the wide-ranging benefits of this technology can only fully be realized through the timely collation, integration and sharing of genomic and clinical/epidemiological metadata by all those involved in the delivery of genomic-informed services. As part of our review on bringing pathogen genomics into 'health-service' practice, we undertook extensive stakeholder consultation to examine the factors integral to achieving effective data sharing and integration. Infrastructure tailored to the needs of clinical users, as well as practical support and policies to facilitate the timely and responsible sharing of data with relevant health authorities and beyond, are all essential. We propose a tiered data sharing and integration model to maximize the immediate and longer term utility of microbial genomics in healthcare. Realizing this model at the scale and sophistication necessary to support national and international infection management services is not uncomplicated. Yet the establishment of a clear data strategy is paramount if failures in containing disease spread due to inadequate knowledge sharing are to be averted, and substantial progress made in tackling the dangers posed by infectious diseases.

  17. 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.

  18. The microbial ecology of permafrost.

    PubMed

    Jansson, Janet K; Taş, Neslihan

    2014-06-01

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

  19. 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)

  20. 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

  1. 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

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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...

  17. Targeting glutamate receptors to tackle the pathogenesis, clinical symptoms and levodopa-induced dyskinesia associated with Parkinson's disease.

    PubMed

    Duty, Susan

    2012-12-01

    The appearance of levodopa-induced dyskinesia (LID) and ongoing degeneration of nigrostriatal dopaminergic neurons are two key features of Parkinson's disease (PD) that current treatments fail to address. Increased glutamate transmission contributes to the motor symptoms in PD, to the striatal plasticity that underpins LID and to the progression of neurodegeneration through excitotoxic mechanisms. Glutamate receptors have therefore long been considered as potential targets for pharmacological intervention in PD, with emphasis on either blocking activation of 2-amino-3-(5-methyl-3-oxo-1,2-oxazol-4-yl)propanoic acid (AMPA), N-methyl-D-aspartate (NMDA) or excitatory metabotropic glutamate (mGlu) 5 receptors or promoting the activation of group II/III mGlu receptors. Following a brief summary of the role of glutamate in PD and LID, this article explores the current status of pharmacological studies in pre-clinical rodent and primate models through to clinical trials, where applicable, that support the potential of glutamate-based therapeutic interventions. To date, AMPA antagonists have shown good efficacy against LID in rat and primate models, but the failure of perampanel to lessen LID in clinical trials casts doubt on the translational potential of this approach. In contrast, antagonists selective for NR2B-containing NMDA receptors were effective against LID in animal models and in small-scale clinical trials, though observed adverse cognitive effects need addressing. So far, mGlu5 antagonists or negative allosteric modulators (NAMs) look set to become the first introduced for tackling LID, with AFQ-056 reported to exhibit good efficacy in phase II clinical trials. NR2B antagonists and mGlu5 NAMs may subsequently prove to also be effective disease-modifying agents if their protective effects in rat and primate models of PD, respectively, are replicated in the next stages of investigation. Finally, group III mGlu4 agonists or positive allosteric modulators (PAMs

  18. 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

  19. [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.

  20. 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.

  1. Microbial Genomics Data from the DOE Joint Genome Institute (JGI)

    DOE Data Explorer

    The JGI makes high-quality genome sequencing data freely available to the greater scientific community through its web portal. Having played a significant role in the federally funded Human Genome Project -- generating the complete sequences of Chromosomes 5, 16, and 19--the JGI has now moved on to contributing in other critical areas of genomics research. While NIH-funded genome sequencing activities continue to emphasize human biomedical targets and applications, the JGI has since shifted its focus to the non-human components of the biosphere, particularly those relevant to the science mission of the Department of Energy. With efficiencies of scale established at the PGF, and capacity now exceeding three billion bases generated on a monthly basis, the JGI has tackled scores of additional genomes. These include more than 60 microbial genomes and many important multicellular organisms and communities of microbes. In partnership with other federal institutions and universities, the JGI is in the process of sequencing a frog (Xenopus tropicalis), a green alga (Chlamydomonas reinhardtii), a diatom (Thalassiosira pseudonana) , the cottonwood tree (Populus trichocarpa), and a host of agriculturally important plants and plant pathogens. Microorganisms, for example those that thrive under extreme conditions such as high acidity, radiation, and metal contamination, are of particular interest to the DOE and JGI. Investigations by JGI and its partners are shedding light on the cellular machinery of microbes and how they can be harnessed to clean up contaminated soil or water, capture carbon from the atmosphere, and produce potentially important sources of energy such as hydrogen and methane. [Excerpt from the JGI page "Who We Are" at http://www.jgi.doe.gov/whoweare/whoweare.html] From the JGI webportal users can view a photo grid of organisims, check assemblies for status, access the Integrated Microbial Genomes (IMG) system to do comparative analysis of publicly available

  2. 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.

  3. 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.

  4. Microbial metabolism of tholin

    NASA Astrophysics Data System (ADS)

    Stoker, C. R.; Boston, P. J.; Mancinelli, R. L.; Segal, W.; Khare, B. N.; Sagan, C.

    1990-05-01

    In this paper, we show that a wide variety of common soil bacteria are able to obtain their carbon and energy needs from tholin (a class of complex organic heteropolymers thought to be widely distributed through the solar system; in this case tholin was produced by passage of electrical discharge through a mixture of methane, ammonia, and water vapor). We have isolated aerobic, anaerobic, and facultatively anaerobic bacteria which are able to use tholin as a sole carbon source. Organisms which metabolize tholin represent a variety of bacterial genera including Clostridium, Pseudomonas, Bacillus, Acinetobacter, Paracoccus, Alcaligenes, Micrococcus, Cornebacterium, Aerobacter, Arthrobacter, Flavobacterium,and Actinomyces. Aerobic tholin-using bacteria were firrst isolated from soils containing unusual or sparse carbon sources. Some of these organisms were found to be facultatively anaerobic. Strictly anaerobic tholin-using bacteria were isolated from both carbon-rich and carbon-poor anaerobic lake muds. In addition, both aerobic and anaerobic tholin-using bacteria were isolated from common soil collected outside the laboratory building. Some, but not all, of the strains that were able to obtain carbon from tholin were also able to obtain their nitrogen requirements from tholin. Bacteria isolated from common soils were tested for their ability to obtain carbon from the water-soluble fraction, the ethanol-soluble fraction, and the water/ethanol-insoluble fraction of the tholin. Of the 3.5 × 10 7 bacteria isolated per gram of common soils, 1.7 0.5, and 0.2%, respectively, were able to obtaib their carbon requirements from the water-soluble fraction, the ethanol-soluble fraction and the water/ethanol-insoluble fraction of the tholin. The palatability of tholins to modern microbes may 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 before the evolution of

  5. Microbial Metagenomics: Beyond the Genome

    NASA Astrophysics Data System (ADS)

    Gilbert, Jack A.; Dupont, Christopher L.

    2011-01-01

    Metagenomics literally means “beyond the genome.” Marine microbial metagenomic databases presently comprise ˜400 billion base pairs of DNA, only ˜3% of that found in 1 ml of seawater. Very soon a trillion-base-pair sequence run will be feasible, so it is time to reflect on what we have learned from metagenomics. We review the impact of metagenomics on our understanding of marine microbial communities. We consider the studies facilitated by data generated through the Global Ocean Sampling expedition, as well as the revolution wrought at the individual laboratory level through next generation sequencing technologies. We review recent studies and discoveries since 2008, provide a discussion of bioinformatic analyses, including conceptual pipelines and sequence annotation and predict the future of metagenomics, with suggestions of collaborative community studies tailored toward answering some of the fundamental questions in marine microbial ecology.

  6. Microbial enhancement of oil recovery

    SciTech Connect

    Finnerty, W.R.; Singer, M.E.

    1983-03-01

    The purpose of this article is to present an overview of a supplementary biotechnology that will potentially aid in obtaining greater oil production and processing capabilities. This supplementary technology involves the application of microbiological processes to specific and well-defined problems in enhanced oil recovery (EOR). The discussion outlines scenarios for various microbiological processes that have been identified as promising areas for research and development, many of which are currently being addressed within the petroleum industry and by the Department of Energy. Microorganisms and microbial products can be used to recover oil from reservoirs. To be successful, the complexity of oil and the physical constraints in the reservoir must be taken into account. The three general approaches are: stimulation of the endogenous microbial population; injection of microorganisms with proven ability to perform well in situ; and the use of microbial products, such as xanthan gum, produced by Xanthomonas campestris.

  7. Universality of human microbial dynamics

    NASA Astrophysics Data System (ADS)

    Bashan, Amir; Gibson, Travis E.; Friedman, Jonathan; Carey, Vincent J.; Weiss, Scott T.; Hohmann, Elizabeth L.; Liu, Yang-Yu

    2016-06-01

    Human-associated microbial communities have a crucial role in determining our health and well-being, and this has led to the continuing development of microbiome-based therapies such as faecal microbiota transplantation. These microbial communities are very complex, dynamic and highly personalized ecosystems, exhibiting a high degree of inter-individual variability in both species assemblages and abundance profiles. It is not known whether the underlying ecological dynamics of these communities, which can be parameterized by growth rates, and intra- and inter-species interactions in population dynamics models, are largely host-independent (that is, universal) or host-specific. If the inter-individual variability reflects host-specific dynamics due to differences in host lifestyle, physiology or genetics, then generic microbiome manipulations may have unintended consequences, rendering them ineffective or even detrimental. Alternatively, microbial ecosystems of different subjects may exhibit universal dynamics, with the inter-individual variability mainly originating from differences in the sets of colonizing species. Here we develop a new computational method to characterize human microbial dynamics. By applying this method to cross-sectional data from two large-scale metagenomic studies—the Human Microbiome Project and the Student Microbiome Project—we show that gut and mouth microbiomes display pronounced universal dynamics, whereas communities associated with certain skin sites are probably shaped by differences in the host environment. Notably, the universality of gut microbial dynamics is not observed in subjects with recurrent Clostridium difficile infection but is observed in the same set of subjects after faecal microbiota transplantation. These results fundamentally improve our understanding of the processes that shape human microbial ecosystems, and pave the way to designing general microbiome-based therapies.

  8. Universality of human microbial dynamics.

    PubMed

    Bashan, Amir; Gibson, Travis E; Friedman, Jonathan; Carey, Vincent J; Weiss, Scott T; Hohmann, Elizabeth L; Liu, Yang-Yu

    2016-06-09

    Human-associated microbial communities have a crucial role in determining our health and well-being, and this has led to the continuing development of microbiome-based therapies such as faecal microbiota transplantation. These microbial communities are very complex, dynamic and highly personalized ecosystems, exhibiting a high degree of inter-individual variability in both species assemblages and abundance profiles. It is not known whether the underlying ecological dynamics of these communities, which can be parameterized by growth rates, and intra- and inter-species interactions in population dynamics models, are largely host-independent (that is, universal) or host-specific. If the inter-individual variability reflects host-specific dynamics due to differences in host lifestyle, physiology or genetics, then generic microbiome manipulations may have unintended consequences, rendering them ineffective or even detrimental. Alternatively, microbial ecosystems of different subjects may exhibit universal dynamics, with the inter-individual variability mainly originating from differences in the sets of colonizing species. Here we develop a new computational method to characterize human microbial dynamics. By applying this method to cross-sectional data from two large-scale metagenomic studies--the Human Microbiome Project and the Student Microbiome Project--we show that gut and mouth microbiomes display pronounced universal dynamics, whereas communities associated with certain skin sites are probably shaped by differences in the host environment. Notably, the universality of gut microbial dynamics is not observed in subjects with recurrent Clostridium difficile infection but is observed in the same set of subjects after faecal microbiota transplantation. These results fundamentally improve our understanding of the processes that shape human microbial ecosystems, and pave the way to designing general microbiome-based therapies.

  9. Synthetic networks in microbial communities

    NASA Astrophysics Data System (ADS)

    Suel, Gurol

    2015-03-01

    While bacteria are single celled organisms, they predominantly reside in structured communities known as biofilms. Cells in biofilms are encapsulated and protected by the extracellular matrix (ECM), which also confines cells in space. During biofilm development, microbial cells are organized in space and over time. Little is known regarding the processes that drive the spatio-temporal organization of microbial communities. Here I will present our latest efforts that utilize synthetic biology approaches to uncover the organizational principles that drive biofilm development. I will also discuss the possible implications of our recent findings in terms of the cost and benefit to biofilm cells.

  10. Systems biology of Microbial Communities

    SciTech Connect

    Navid, A; Ghim, C; Fenley, A; Yoon, S; Lee, S; Almaas, E

    2008-04-11

    Microbes exist naturally in a wide range of environments, spanning the extremes of high acidity and high temperature to soil and the ocean, in communities where their interactions are significant. We present a practical discussion of three different approaches for modeling microbial communities: rate equations, individual-based modeling, and population dynamics. We illustrate the approaches with detailed examples. Each approach is best fit to different levels of system representation, and they have different needs for detailed biological input. Thus, this set of approaches is able to address the operation and function of microbial communities on a wide range of organizational levels.

  11. Autophagy, Immunity, and Microbial Adaptations

    PubMed Central

    Deretic, Vojo; Levine, Beth

    2009-01-01

    Autophagy adjusts cellular biomass and function in response to diverse stimuli, including infection. Autophagy plays specific roles in shaping immune system development, fueling host innate and adaptive immune responses, and directly controlling intracellular microbes as a cell-autonomous innate defense. As an evolutionary counterpoint, intracellular pathogens have evolved to block autophagic microbicidal defense and subvert host autophagic responses for their survival or growth. The ability of eukaryotic pathogens to deploy their own autophagic machinery may also contribute to microbial pathogenesis. Thus, a complex interplay between autophagy and microbial adaptations against autophagy governs the net outcome of host-microbe encounters. PMID:19527881

  12. Integrated Environmental Modeling: Quantitative Microbial Risk Assessment

    EPA Science Inventory

    The presentation discusses the need for microbial assessments and presents a road map associated with quantitative microbial risk assessments, through an integrated environmental modeling approach. A brief introduction and the strengths of the current knowledge are illustrated. W...

  13. THE FUTURE OF MICROBIAL SOURCE TRACKING STUDIES

    EPA Science Inventory

    Microbial source tracking (MST) is differentiated from traditional microbial water quality efforts by the need to identify the host species from which the bacteria originate, rather than necessarily identifying an individual point source. Despite recent advances in the developmen...

  14. Quorum sensing and microbial drug resistance.

    PubMed

    Yufan, Chen; Shiyin, Liu; Zhibin, Liang; Mingfa, Lv; Jianuan, Zhou; Lianhui, Zhang

    2016-10-20

    Microbial drug resistance has become a serious problem of global concern, and the evolution and regulatory mechanisms of microbial drug resistance has become a hotspot of research in recent years. Recent studies showed that certain microbial resistance mechanisms are regulated by quorum sensing system. Quorum sensing is a ubiquitous cell-cell communication system in the microbial world, which associates with cell density. High-density microbial cells produce sufficient amount of small signal molecules, activating a range of downstream cellular processes including virulence and drug resistance mechanisms, which increases bacterial drug tolerance and causes infections on host organisms. In this review, the general mechanisms of microbial drug resistance and quorum-sensing systems are summarized with a focus on the association of quorum sensing and chemical signaling systems with microbial drug resistance mechanisms, including biofilm formation and drug efflux pump. The potential use of quorum quenching as a new strategy to control microbial resistance is also discussed.

  15. Microbially induced and microbially catalysed precipitation: two different carbonate factories

    NASA Astrophysics Data System (ADS)

    Meister, Patrick

    2016-04-01

    The landmark paper by Schlager (2003) has revealed three types of benthic carbonate production referred to as "carbonate factories", operative at different locations at different times in Earth history. The tropical or T-factory comprises the classical platforms and fringing reefs and is dominated by carbonate precipitation by autotrophic calcifying metazoans ("biotically controlled" precipitation). The cool or C-factory is also biotically controlled but via heterotrophic, calcifying metazoans in cold and deep waters at the continental margins. A further type is the mud-mound or M-factory, where carbonate precipitation is supported by microorganisms but not controlled by a specific enzymatic pathway ("biotically induced" precipitation). How exactly the microbes influence precipitation is still poorly understood. Based on recent experimental and field studies, the microbial influence on modern mud mound and microbialite growth includes two fundamentally different processes: (1) Metabolic activity of microbes may increase the saturation state with respect to a particular mineral phase, thereby indirectly driving the precipitation of the mineral phase: microbially induced precipitation. (2) In a situation, where a solution is already supersaturated but precipitation of the mineral is inhibited by a kinetic barrier, microbes may act as a catalyser, i.e. they lower the kinetic barrier: microbially catalysed precipitation. Such a catalytic effect can occur e.g. via secreted polymeric substances or specific chemical groups on the cell surface, at which the minerals nucleate or which facilitate mechanistically the bonding of new ions to the mineral surface. Based on these latest developments in microbialite formation, I propose to extend the scheme of benthic carbonate factories of Schlager et al. (2003) by introducing an additional branch distinguishing microbially induced from microbially catalysed precipitation. Although both mechanisms could be operative in a M

  16. In situ microbial filter used for bioremediation

    DOEpatents

    Carman, M. Leslie; Taylor, Robert T.

    2000-01-01

    An improved method for in situ microbial filter bioremediation having increasingly operational longevity of an in situ microbial filter emplaced into an aquifer. A method for generating a microbial filter of sufficient catalytic density and thickness, which has increased replenishment interval, improved bacteria attachment and detachment characteristics and the endogenous stability under in situ conditions. A system for in situ field water remediation.

  17. The microbial contribution to macroecology

    PubMed Central

    Barberán, Albert; Casamayor, Emilio O.; Fierer, Noah

    2014-01-01

    There has been a recent explosion of research within the field of microbial ecology that has been fueled, in part, by methodological improvements that make it feasible to characterize microbial communities to an extent that was inconceivable only a few years ago. Furthermore, there is increasing recognition within the field of ecology that microorganisms play a critical role in the health of organisms and ecosystems. Despite these developments, an important gap still persists between the theoretical framework of macroecology and microbial ecology. We highlight two idiosyncrasies of microorganisms that are fundamental to understanding macroecological patterns and their mechanistic drivers. First, high dispersal rates provide novel opportunities to test the relative importance of niche, stochastic, and historical processes in structuring biological communities. Second, high speciation rates potentially lead to the convergence of ecological and evolutionary time scales. After reviewing these unique aspects, we discuss strategies for improving the conceptual integration of microbes into macroecology. As examples, we discuss the use of phylogenetic ecology as an integrative approach to explore patterns across the tree of life. Then we demonstrate how two general theories of biodiversity (i.e., the recently developed theory of stochastic geometry and the neutral theory) can be adapted to microorganisms. We demonstrate how conceptual models that integrate evolutionary and ecological mechanisms can contribute to the unification of microbial ecology and macroecology. PMID:24829564

  18. Foodborne illness and microbial agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foodborne illnesses result from the consumption of food containing microbial agents such as bacteria, viruses, parasites or food contaminated by poisonous chemicals or bio-toxins. Pathogen proliferation is due to nutrient composition of foods, which are capable of supporting the growth of microorgan...

  19. Commercial production of microbial enzymes

    SciTech Connect

    Munro, I.G.

    1985-01-01

    The advantages and uses of industrially produced microbial enzymes are described. The processes involved in the production of these enzymes, cultivation techniques, enzyme extraction, enzyme purification and immobilization are outlined. Both the history of enzyme technology and its future development are discussed.

  20. Microbial ecology of watery kimchi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The biochemistry and microbial ecology of 2 similar types of watery (mul) kimchi, containing sliced and unsliced radish and vegetables (nabak and dongchimi, respectively), were investigated. Samples from kimchi were fermented at 4, 10, and 20 °C were analyzed by plating on differential and selective...

  1. Understanding Microbial Divisions of Labor

    PubMed Central

    Zhang, Zheren; Claessen, Dennis; Rozen, Daniel E.

    2016-01-01

    Divisions of labor are ubiquitous in nature and can be found at nearly every level of biological organization, from the individuals of a shared society to the cells of a single multicellular organism. Many different types of microbes have also evolved a division of labor among its colony members. Here we review several examples of microbial divisions of labor, including cases from both multicellular and unicellular microbes. We first discuss evolutionary arguments, derived from kin selection, that allow divisions of labor to be maintained in the face of non-cooperative cheater cells. Next we examine the widespread natural variation within species in their expression of divisions of labor and compare this to the idea of optimal caste ratios in social insects. We highlight gaps in our understanding of microbial caste ratios and argue for a shift in emphasis from understanding the maintenance of divisions of labor, generally, to instead focusing on its specific ecological benefits for microbial genotypes and colonies. Thus, in addition to the canonical divisions of labor between, e.g., reproductive and vegetative tasks, we may also anticipate divisions of labor to evolve to reduce the costly production of secondary metabolites or secreted enzymes, ideas we consider in the context of streptomycetes. The study of microbial divisions of labor offers opportunities for new experimental and molecular insights across both well-studied and novel model systems. PMID:28066387

  2. Life Support Systems Microbial Challenges

    NASA Technical Reports Server (NTRS)

    Roman, Monsi C.

    2010-01-01

    Many microbiological studies were performed during the development of the Space Station Water Recovery and Management System from1990-2009. Studies include assessments of: (1) bulk phase (planktonic) microbial population (2) biofilms, (3) microbially influenced corrosion (4) biofouling treatments. This slide presentation summarizes the studies performed to assess the bulk phase microbial community during the Space Station Water Recovery Tests (WRT) from 1990 to 1998. This report provides an overview of some of the microbiological analyses performed during the Space Station WRT program. These tests not only integrated several technologies with the goal of producing water that met NASA s potable water specifications, but also integrated humans, and therefore human flora into the protocols. At the time these tests were performed, not much was known (or published) about the microbial composition of these types of wastewater. It is important to note that design changes to the WRS have been implemented over the years and results discussed in this report might be directly related to test configurations that were not chosen for the final flight configuration. Results microbiological analyses performed Conclusion from the during the WRT showed that it was possible to recycle water from different sources, including urine, and produce water that can exceed the quality of municipally produced water.

  3. Microbial transformation of antimalarial terpenoids.

    PubMed

    Parshikov, Igor A; Netrusov, Alexander I; Sutherland, John B

    2012-01-01

    The fungal and bacterial transformation of terpenoids derived from plant essential oils, especially the sesquiterpenoid artemisinin from Artemisia annua, has produced several new candidate drugs for the treatment of malaria. Obtaining new derivatives of terpenoids, including artemisinin derivatives with increased antimalarial activity, is an important goal of research in microbial biotechnology and medicinal chemistry.

  4. Simplifying microbial electrosynthesis reactor design

    PubMed Central

    Giddings, Cloelle G. S.; Nevin, Kelly P.; Woodward, Trevor; Lovley, Derek R.; Butler, Caitlyn S.

    2015-01-01

    Microbial electrosynthesis, an artificial form of photosynthesis, can efficiently convert carbon dioxide into organic commodities; however, this process has only previously been demonstrated in reactors that have features likely to be a barrier to scale-up. Therefore, the possibility of simplifying reactor design by both eliminating potentiostatic control of the cathode and removing the membrane separating the anode and cathode was investigated with biofilms of Sporomusa ovata. S. ovata reduces carbon dioxide to acetate and acts as the microbial catalyst for plain graphite stick cathodes as the electron donor. In traditional ‘H-cell’ reactors, where the anode and cathode chambers were separated with a proton-selective membrane, the rates and columbic efficiencies of microbial electrosynthesis remained high when electron delivery at the cathode was powered with a direct current power source rather than with a potentiostat-poised cathode utilized in previous studies. A membrane-less reactor with a direct-current power source with the cathode and anode positioned to avoid oxygen exposure at the cathode, retained high rates of acetate production as well as high columbic and energetic efficiencies. The finding that microbial electrosynthesis is feasible without a membrane separating the anode from the cathode, coupled with a direct current power source supplying the energy for electron delivery, is expected to greatly simplify future reactor design and lower construction costs. PMID:26029199

  5. Towards a Microbial Thermoelectric Cell

    PubMed Central

    Rodríguez-Barreiro, Raúl; Abendroth, Christian; Vilanova, Cristina; Moya, Andrés; Porcar, Manuel

    2013-01-01

    Microbial growth is an exothermic process. Biotechnological industries produce large amounts of heat, usually considered an undesirable by-product. In this work, we report the construction and characterization of the first microbial thermoelectric cell (MTC), in which the metabolic heat produced by a thermally insulated microbial culture is partially converted into electricity through a thermoelectric device optimized for low ΔT values. A temperature of 41°C and net electric voltage of around 250–600 mV was achieved with 1.7 L baker’s yeast culture. This is the first time microbial metabolic energy has been converted into electricity with an ad hoc thermoelectric device. These results might contribute towards developing a novel strategy to harvest excess heat in the biotechnology industry, in processes such as ethanol fermentation, auto thermal aerobic digestion (ATAD) or bioremediation, which could be coupled with MTCs in a single unit to produce electricity as a valuable by-product of the primary biotechnological product. Additionally, we propose that small portable MTCs could be conceived and inoculated with suitable thermophilic of hyperthermophilic starter cultures and used for powering small electric devices. PMID:23468862

  6. Microbial Fuel Cells and Sensors

    DTIC Science & Technology

    2007-11-02

    funding foreign research over Quality U.S. research needs to be investigated by government officials. PATENT INFORMATION: Improved fuel cell designs and...Zeikus. Analysis of microbial electrochemical activity in marine sediment. (In preparation) REPOT D CUM NTA ON AGEForm Approved REPOT D CUM NTATON

  7. 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.

  8. Universality of Human Microbial Dynamics

    PubMed Central

    Bashan, Amir; Gibson, Travis E.; Friedman, Jonathan; Carey, Vincent J.; Weiss, Scott T.; Hohmann, Elizabeth L.; Liu, Yang-Yu

    2016-01-01

    The recent realization that human-associated microbial communities play a crucial role in determining our health and well-being1,2 has led to the ongoing development of microbiome-based therapies3 such as fecal microbiota transplantation4,5. Thosemicrobial communities are very complex, dynamic6 and highly personalized ecosystems3,7, exhibiting a high degree of inter-individual variability in both species assemblages8 and abundance profiles9. It is not known whether the underlying ecological dynamics, which can be parameterized by growth rates, intra- and inter-species interactions in population dynamics models10, are largely host-independent (i.e. “universal”) or host-specific. If the inter-individual variability reflects host-specific dynamics due to differences in host lifestyle11, physiology12, or genetics13, then generic microbiome manipulations may have unintended consequences, rendering them ineffectual or even detrimental. Alternatively, microbial ecosystems of different subjects may follow a universal dynamics with the inter-individual variability mainly stemming from differences in the sets of colonizing species7,14. Here we developed a novel computational method to characterize human microbial dynamics. Applying this method to cross-sectional data from two large-scale metagenomic studies, the Human Microbiome Project9,15 and the Student Microbiome Project16, we found that both gut and mouth microbiomes display pronounced universal dynamics, whereas communities associated with certain skin sites are likely shaped by differences in the host environment. Interestingly, the universality of gut microbial dynamics is not observed in subjects with recurrent Clostridium difficile infection17 but is observed in the same set of subjects after fecal microbiota transplantation. These results fundamentally improve our understanding of forces and processes shaping human microbial ecosystems, paving the way to design general microbiome-based therapies18. PMID

  9. GIS-based analysis of drinking-water supply structures: a module for microbial risk assessment.

    PubMed

    Kistemann, T; Herbst, S; Dangendorf, F; Exner, M

    2001-05-01

    Water-related infections constitute an important health impact world-wide. A set of tools serving for Microbial Risk Assessment (MRA) of waterborne diseases should comprise the entire drinking-water management system and take into account the Hazard Analysis and Critical Control Point (HACCP) concept which provides specific Critical Control Points (CCPs) reflecting each step of drinking-water provision. A Geographical Information System (GIS) study concerning water-supply structure (WSS) was conducted in the Rhein-Berg District (North Rhine-Westphalia, Germany). As a result, suitability of the existing water databases HYGRIS (hydrological basis geo-information system) and TEIS (drinking-water recording and information system) for the development of a WSS-GIS module could be demonstrated. Spatial patterns within the integrated raw and drinking-water data can easily be uncovered by GIS-specific options. The application of WSS-GIS allows a rapid visualization and analysis of drinking-water supply structure and offers huge advantages concerning microbial monitoring of raw and drinking water as well as recognition and investigation of incidents and outbreaks. Increasing requests regarding health protection and health reporting, demands for a better outbreak management and water-related health impacts of global climate change are major challenges of future water management to be tackled with methods including spatial analysis. GIS is assumed to be a very useful tool to meet these requirements.

  10. Toward understanding, managing, and protecting microbial ecosystems.

    PubMed

    Bodelier, Paul L E

    2011-01-01

    Microbial communities are at the very basis of life on earth, catalyzing biogeochemical reactions driving global nutrient cycles. However, unlike for plants and animals, microbial diversity is not on the biodiversity-conservation agenda. The latter, however, would imply that microbial diversity is not under any threat by anthropogenic disturbance or climate change. This maybe a misconception caused by the rudimentary knowledge we have concerning microbial diversity and its role in ecosystem functioning. This perspective paper identifies major areas with knowledge gaps within the field of environmental microbiology that preclude a comprehension of microbial ecosystems on the level we have for plants and animals. Opportunities and challenges are pointed out to open the microbial black box and to go from descriptive to predictive microbial ecology.

  11. Toward Understanding, Managing, and Protecting Microbial Ecosystems

    PubMed Central

    Bodelier, Paul L. E.

    2011-01-01

    Microbial communities are at the very basis of life on earth, catalyzing biogeochemical reactions driving global nutrient cycles. However, unlike for plants and animals, microbial diversity is not on the biodiversity–conservation agenda. The latter, however, would imply that microbial diversity is not under any threat by anthropogenic disturbance or climate change. This maybe a misconception caused by the rudimentary knowledge we have concerning microbial diversity and its role in ecosystem functioning. This perspective paper identifies major areas with knowledge gaps within the field of environmental microbiology that preclude a comprehension of microbial ecosystems on the level we have for plants and animals. Opportunities and challenges are pointed out to open the microbial black box and to go from descriptive to predictive microbial ecology. PMID:21747797

  12. The index of microbial air contamination.

    PubMed

    Pasquarella, C; Pitzurra, O; Savino, A

    2000-12-01

    The standard index of microbial air contamination (IMA) for the measurement of microbial air contamination in environments at risk is described. The method quantifies the microbial flow directly related to the contamination of surfaces coming from microbes that reach critical points by falling on to them. The index of microbial air contamination is based on the count of the microbial fallout on to Petri dishes left open to the air according to the 1/1/1 scheme (for 1h, 1m from the floor, at least 1m away from walls or any obstacle). Classes of contamination and maximum acceptable levels have been established. The index of microbial air contamination has been tested in many different places: in hospitals, in food industries, in art galleries, aboard the MIR space station and also in the open air. It has proved to be a reliable and useful tool for monitoring the microbial surface contamination settling from the air in any environment.

  13. Microbial astronauts: assembling microbial communities for advanced life support systems

    NASA Technical Reports Server (NTRS)

    Roberts, M. S.; Garland, J. L.; Mills, A. L.

    2004-01-01

    Extension of human habitation into space requires that humans carry with them many of the microorganisms with which they coexist on Earth. The ubiquity of microorganisms in close association with all living things and biogeochemical processes on Earth predicates that they must also play a critical role in maintaining the viability of human life in space. Even though bacterial populations exist as locally adapted ecotypes, the abundance of individuals in microbial species is so large that dispersal is unlikely to be limited by geographical barriers on Earth (i.e., for most environments "everything is everywhere" given enough time). This will not be true for microbial communities in space where local species richness will be relatively low because of sterilization protocols prior to launch and physical barriers between Earth and spacecraft after launch. Although community diversity will be sufficient to sustain ecosystem function at the onset, richness and evenness may decline over time such that biological systems either lose functional potential (e.g., bioreactors may fail to reduce BOD or nitrogen load) or become susceptible to invasion by human-associated microorganisms (pathogens) over time. Research at the John F. Kennedy Space Center has evaluated fundamental properties of microbial diversity and community assembly in prototype bioregenerative systems for NASA Advanced Life Support. Successional trends related to increased niche specialization, including an apparent increase in the proportion of nonculturable types of organisms, have been consistently observed. In addition, the stability of the microbial communities, as defined by their resistance to invasion by human-associated microorganisms, has been correlated to their diversity. Overall, these results reflect the significant challenges ahead for the assembly of stable, functional communities using gnotobiotic approaches, and the need to better define the basic biological principles that define ecosystem

  14. Key Concepts in Microbial Oceanography

    NASA Astrophysics Data System (ADS)

    Bruno, B. C.; Achilles, K.; Walker, G.; Weersing, K.; Team, A

    2008-12-01

    The Center for Microbial Oceanography: Research and Education (C-MORE) is a multi-institution Science and Technology Center, established by the National Science Foundation in 2006. C-MORE's research mission is to facilitate a more comprehensive understanding of the diverse assemblages of microorganisms in the sea, ranging from the genetic basis of marine microbial biogeochemistry including the metabolic regulation and environmental controls of gene expression, to the processes that underpin the fluxes of carbon, related bioelements, and energy in the marine environment. The C-MORE education and outreach program is focused on increasing scientific literacy in microbial oceanography among students, educators, and the general public. A first step toward this goal is defining the key concepts that constitute microbial oceanography. After lengthy discussions with scientists and educators, both within and outside C-MORE, we have arrived at six key concepts: 1) Marine microbes are very small and have been around for a long time; 2) Life on Earth could not exist without microbes; 3) Most marine microbes are beneficial; 4) Microbes are everywhere: they are extremely abundant and diverse; 5) Microbes significantly impact our global climate; and 6) There are new discoveries every day in the field of microbial oceanography. A C-MORE-produced brochure on these six key concepts will be distributed at the meeting. Advanced copies may be requested by email or downloaded from the C-MORE web site(http://cmore.soest.hawaii.edu/downloads/MO_key_concepts_hi-res.pdf). This brochure also includes information on career pathways in microbial oceanography, with the aim of broadening participation in the field. C-MORE is eager to work in partnership to incorporate these key concepts into other science literacy publications, particularly those involving ocean and climate literacy. We thank the following contributors and reviewers: P Chisholm, A Dolberry, and A Thompson (MIT); N Lawrence

  15. 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

  16. Microbial source tracking: a forensic technique for microbial source identification?

    PubMed

    Stapleton, Carl M; Wyer, Mark D; Kay, David; Crowther, John; McDonald, Adrian T; Walters, Martin; Gawler, Andrew; Hindle, Terry

    2007-05-01

    As the requirements of the Water Framework Directive (WFD) and the US Clean Water Act (USCWA) for the maintenance of microbiological water quality in 'protected areas' highlight, there is a growing recognition that integrated management of point and diffuse sources of microbial pollution is essential. New information on catchment microbial dynamics and, in particular, the sources of faecal indicator bacteria found in bathing and shellfish harvesting waters is a pre-requisite for the design of any 'programme of measures' at the drainage basin scale to secure and maintain compliance with existing and new health-based microbiological standards. This paper reports on a catchment-scale microbial source tracking (MST) study in the Leven Estuary drainage basin, northwest England, an area for which quantitative faecal indicator source apportionment empirical data and land use information were also collected. Since previous MST studies have been based on laboratory trials using 'manufactured' samples or analyses of spot environmental samples without the contextual microbial flux data (under high and low flow conditions) and source information, such background data are needed to evaluate the utility of MST in USCWA total maximum daily load (TMDL) assessments or WFD 'Programmes of Measures'. Thus, the operational utility of MST remains in some doubt. The results of this investigation, using genotyping of Bacteroidetes using polymerase chain reaction (PCR) and male-specific ribonucleic acid coliphage (F + RNA coliphage) using hybridisation, suggest some discrimination is possible between livestock- and human-derived faecal indicator concentrations but, in inter-grade areas, the degree to which the tracer picture reflected the land use pattern and probable faecal indicator loading were less distinct. Interestingly, the MST data was more reliable on high flow samples when much of the faecal indicator flux from catchment systems occurs. Whilst a useful supplementary tool, the MST

  17. 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.

  18. Synthetic microbial ecosystems for biotechnology.

    PubMed

    Pandhal, Jagroop; Noirel, Josselin

    2014-06-01

    Most highly controlled and specific applications of microorganisms in biotechnology involve pure cultures. Maintaining single strain cultures is important for industry as contaminants can reduce productivity and lead to longer "down-times" during sterilisation. However, microbes working together provide distinct advantages over pure cultures. They can undertake more metabolically complex tasks, improve efficiency and even expand applications to open systems. By combining rapidly advancing technologies with ecological theory, the use of microbial ecosystems in biotechnology will inevitably increase. This review provides insight into the use of synthetic microbial communities in biotechnology by applying the engineering paradigm of measure, model, manipulate and manufacture, and illustrate the emerging wider potential of the synthetic ecology field. Systems to improve biofuel production using microalgae are also discussed.

  19. Microbial Flocculant for Nature Soda

    SciTech Connect

    Qin, Peiyong; Zhang, Tong; Chen, Cuixian

    2004-03-31

    Microbial flocculant for nature soda has been studied. Lactobacillus TRJ21, which was able to produce an excellent biopolymer flocculant for nature soda, was obtained in our lab. The microbial flocculant was mainly produced when the bacteria laid in stationary growth phase. Fructose or glucose, as carbon sources, were more favorable for the bacterial growth and flocculant production. The bacteria was able to use ammonium sulfate or Urea as nitrogen to produce flocculant, but was not able to use peptone effectively. High C/N ratio was more favorable to Lactobacillus TRJ21 growth and flocculant production than low C/N ratio. The biopolymer flocculant was mainly composed of polysaccharide and protein with a molecular weight 1.38x106 by gel permeation chromatography. It was able to be easily purified from the culture medium by acetone. Protein in the flocculant was tested for the flocculating activity ingredient by heating the flocculant.

  20. Toward Engineering Synthetic Microbial Metabolism

    PubMed Central

    McArthur, George H.; Fong, Stephen S.

    2010-01-01

    The generation of well-characterized parts and the formulation of biological design principles in synthetic biology are laying the foundation for more complex and advanced microbial metabolic engineering. Improvements in de novo DNA synthesis and codon-optimization alone are already contributing to the manufacturing of pathway enzymes with improved or novel function. Further development of analytical and computer-aided design tools should accelerate the forward engineering of precisely regulated synthetic pathways by providing a standard framework for the predictable design of biological systems from well-characterized parts. In this review we discuss the current state of synthetic biology within a four-stage framework (design, modeling, synthesis, analysis) and highlight areas requiring further advancement to facilitate true engineering of synthetic microbial metabolism. PMID:20037734

  1. Microbial activity at Yucca Mountain

    SciTech Connect

    Horn, J.M.; Meike, A.

    1995-09-25

    The U.S. Department of Energy is engaged in a suitability study for a potential geological repository at Yucca Mountain, Nevada, for the containment and storage of commercially generated spent fuel and defense high-level nuclear waste. There is growing recognition of the role that biotic factors could play in this repository, either directly through microbially induced corrosion (MIC), or indirectly by altering the chemical environment or contributing to the transport of radionuclides. As a first step toward describing and predicting these processes, a workshop was held on April 10-12, 1995, in Lafayette, California. The immediate aims of the workshop were: (1) To identify microbially related processes relevant to the design of a radioactive waste repository under conditions similar to those at Yucca Mountain. (2) To determine parameters that are critical to the evaluation of a disturbed subterranean environment. (3) To define the most effective means of investigating the factors thus identified.

  2. Subsurface microbial habitats on Mars

    NASA Technical Reports Server (NTRS)

    Boston, P. J.; Mckay, C. P.

    1991-01-01

    We developed scenarios for shallow and deep subsurface cryptic niches for microbial life on Mars. Such habitats could have considerably prolonged the persistence of life on Mars as surface conditions became increasingly inhospitable. The scenarios rely on geothermal hot spots existing below the near or deep subsurface of Mars. Recent advances in the comparatively new field of deep subsurface microbiology have revealed previously unsuspected rich aerobic and anaerobic microbal communities far below the surface of the Earth. Such habitats, protected from the grim surface conditions on Mars, could receive warmth from below and maintain water in its liquid state. In addition, geothermally or volcanically reduced gases percolating from below through a microbiologically active zone could provide the reducing power needed for a closed or semi-closed microbial ecosystem to thrive.

  3. Microbial regulatory and metabolic networks.

    PubMed

    Cho, Byung-Kwan; Charusanti, Pep; Herrgård, Markus J; Palsson, Bernhard O

    2007-08-01

    Reconstruction of transcriptional regulatory and metabolic networks is the foundation of large-scale microbial systems and synthetic biology. An enormous amount of information including the annotated genomic sequences and the genomic locations of DNA-binding regulatory proteins can be used to define metabolic and regulatory networks in cells. In particular, advances in experimental methods to map regulatory networks in microbial cells have allowed reliable data-driven reconstruction of these networks. Recent work on metabolic engineering and experimental evolution of microbes highlights the key role of global regulatory networks in controlling specific metabolic processes and the need to consider the integrated function of multiple types of networks for both scientific and engineering purposes.

  4. Sonoassisted microbial reduction of chromium.

    PubMed

    Kathiravan, Mathur Nadarajan; Karthick, Ramalingam; Muthu, Naggapan; Muthukumar, Karuppan; Velan, Manickam

    2010-04-01

    This study presents sonoassisted microbial reduction of hexavalent chromium (Cr(VI)) using Bacillus sp. isolated from tannery effluent contaminated site. The experiments were carried out with free cells in the presence and absence of ultrasound. The optimum pH and temperature for the reduction of Cr(VI) by Bacillus sp. were found to be 7.0 and 37 degrees C, respectively. The Cr(VI) reduction was significantly influenced by the electron donors and among the various electron donors studied, glucose offered maximum reduction. The ultrasound-irradiated reduction of Cr(VI) with Bacillus sp. showed efficient Cr(VI) reduction. The percent reduction was found to increase with an increase in biomass concentration and decrease with an increase in initial concentration. The changes in the functional groups of Bacillus sp., before and after chromium reduction were observed with FTIR spectra. Microbial growth was described with Monod and Andrews model and best fit was observed with Andrews model.

  5. Microbial starch-binding domain.

    PubMed

    Rodríguez-Sanoja, Romina; Oviedo, Norma; Sánchez, Sergio

    2005-06-01

    Glucosidic bonds from different non-soluble polysaccharides such as starch, cellulose and xylan are hydrolyzed by amylases, cellulases and xylanases, respectively. These enzymes are produced by microorganisms. They have a modular structure that is composed of a catalytic domain and at least one non-catalytic domain that is involved in polysaccharide binding. Starch-binding modules are present in microbial enzymes that are involved in starch metabolism; these are classified into several different families on the basis of their amino acid sequence similarities. Such binding domains promote attachment to the substrate and increase its concentration at the active site of the enzyme, which allows microorganisms to degrade non-soluble starch. Fold similarities are better conserved than sequences; nevertheless, it is possible to notice two evolutionary clusters of microbial starch-binding domains. These domains have enormous potential as tags for protein immobilization, as well as for the tailoring of enzymes that play a part in polysaccharide metabolism.

  6. 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.

  7. Microbial exchange experiment AR-002

    NASA Technical Reports Server (NTRS)

    Taylor, G. R.; Kropp, K. D.; Henney, M. R.; Ekblad, S. S.; Groves, T. O.; Molina, T. C.; Decelle, J. G.; Carmichael, C. F.; Gehring, N. J.; Young, E. L.

    1976-01-01

    Operational aspects associated with the experiment and the activities of medically important microorganisms recovered from the Apollo crewmen are evaluated. A variety of potential pathogens was recovered from each of the prime and backup crew members before and after flight. However, no disease events were reported. Candida albicans and Staphylococcus aureus were shown to be transferred from one crewmember to another during the flight. No other medically significant changes in the microbial population were observed.

  8. Microbial enhanced oil recovery research

    SciTech Connect

    Sharma, M.M.; Georgiou, G.

    1990-01-01

    The objective of this work is to develop an engineering framework for the exploitation of microorganisms to enhance oil recovery. Specific goals include: (1) investigation of the mechanisms of microbially induced oil mobilization; (2) the production, isolation, chemical characterization and study of the physical properties of microbially produced surfactants; (3) model studies in sandstone cores for the characterization of the interactions between growing microbially cultures and oil reservoirs; (4) development of simulators for MEOR; and (5) design of operational strategies for the sequential injection of microorganisms and nutrient in reservoirs are: (1) systematic discussion of the mechanisms important in MEOR processes; (2) Measurement of the growth characteristics of Bacillus Licheniformis under various conditions of pH, temperature and salt concentration for both aerobic and anaerobic growth.; (3) measurement of interfacial tension reducing ability of the biosurfactant under different conditions of pH and salt concentration; (4) development of some preliminary methods to concentrate and characterize the biosurfactant; (5) development of a compositional numerical simulator for MEOR processes; and (6) Measurement of the lowest interfacial tension (IFT) value reported for biosurfactants to date. Demonstration of the fact that the low IFT values required for oil recovery can be attained with biosurfactants.

  9. 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

  10. In-Flight Microbial Monitor

    NASA Technical Reports Server (NTRS)

    Zeitlin, Nancy; Mullenix, Pamela; Wheeler, Raymond M.; Ruby, Anna Maria

    2015-01-01

    Previous research has shown that potential human pathogens have been detected on the International Space Station (ISS). New microorganisms are introduced with every exchange of crew and cargo. Microorganisms introduced to the ISS are readily transferred between crew and subsystems (i.e., ECLSS, environmental control and life support systems). Current microbial characterization methods require a culture-based enrichment of microorganisms and at least a 48-hour incubation time. This increases the microbial load while detecting only a limited number of microorganisms. The culture-based method detects approximately 1-10% of the total organisms present and provides no identification. To identify and enumerate ISS samples requires that the microbes be returned to Earth for complete analysis. Therefore, a more expedient, low-cost, inflight method of microbial detection, identification, and enumeration is needed. The RAZOR EX, a ruggedized, commercial off the shelf, real-time PCR field instrument was tested for its ability to detect microorganisms at low concentrations within one hour. Escherichia coli, Salmonella enterica Typhimurium, and Pseudomonas aeruginosa were detected at low levels using real-time DNA amplification. Total heterotrophic counts could also be detected using a 16S gene marker that can identify up to 98% of all bacteria. To reflect viable cells found in the samples, RNA was also detectable using a modified, single-step reverse transcription reaction.

  11. Microbial Engineering for Aldehyde Synthesis

    PubMed Central

    Kunjapur, Aditya M.

    2015-01-01

    Aldehydes are a class of chemicals with many industrial uses. Several aldehydes are responsible for flavors and fragrances present in plants, but aldehydes are not known to accumulate in most natural microorganisms. In many cases, microbial production of aldehydes presents an attractive alternative to extraction from plants or chemical synthesis. During the past 2 decades, a variety of aldehyde biosynthetic enzymes have undergone detailed characterization. Although metabolic pathways that result in alcohol synthesis via aldehyde intermediates were long known, only recent investigations in model microbes such as Escherichia coli have succeeded in minimizing the rapid endogenous conversion of aldehydes into their corresponding alcohols. Such efforts have provided a foundation for microbial aldehyde synthesis and broader utilization of aldehydes as intermediates for other synthetically challenging biochemical classes. However, aldehyde toxicity imposes a practical limit on achievable aldehyde titers and remains an issue of academic and commercial interest. In this minireview, we summarize published efforts of microbial engineering for aldehyde synthesis, with an emphasis on de novo synthesis, engineered aldehyde accumulation in E. coli, and the challenge of aldehyde toxicity. PMID:25576610

  12. Chip-SIP: Stable Isotope Probing of RNA combining phylogenetic microarrays and Secondary Ion Mass Spectrometry (NanoSIMS) to link structure and function in microbial systems (Invited)

    NASA Astrophysics Data System (ADS)

    Mayali, X.; Weber, P. K.; Mabery, S.; Dekas, A.; Pett-Ridge, J.

    2013-12-01

    A primary goal of microbial ecology is to understand the biogeochemical role of individual microbial taxa in the environment. Our approach to tackle this challenge (Chip-SIP) involves the combination of high-density phylogenetic microarrays ('chips') and Stable Isotope Probing (SIP) to directly link identity and function. Microbial communities are incubated in the presence of substrate(s) enriched in 13C or 15N, RNA is extracted and hybridized onto a microarray synthesized on a conductive surface, and the array is analyzed with a NanoSIMS imaging mass spectrometer to quantify isotopic enrichment of individual probes. After testing the method with mixtures of stable isotope labeled laboratory isolates, we have investigated organic and inorganic carbon and nitrogen incorporation by microbial taxa in various ecosystems including San Francisco Bay, the coastal Pacific Ocean, California soils, and the hindguts of wood-eating beetles. We will summarize the methodology, describe the types of questions it has allowed us to investigate, and discuss some testable hypotheses about biogeochemical cycling in various environments that can benefit from this approach.

  13. Microbial mercury methylation in Antarctic sea ice.

    PubMed

    Gionfriddo, Caitlin M; Tate, Michael T; Wick, Ryan R; Schultz, Mark B; Zemla, Adam; Thelen, Michael P; Schofield, Robyn; Krabbenhoft, David P; Holt, Kathryn E; Moreau, John W

    2016-08-01

    Atmospheric deposition of mercury onto sea ice and circumpolar sea water provides mercury for microbial methylation, and contributes to the bioaccumulation of the potent neurotoxin methylmercury in the marine food web. Little is known about the abiotic and biotic controls on microbial mercury methylation in polar marine systems. However, mercury methylation is known to occur alongside photochemical and microbial mercury reduction and subsequent volatilization. Here, we combine mercury speciation measurements of total and methylated mercury with metagenomic analysis of whole-community microbial DNA from Antarctic snow, brine, sea ice and sea water to elucidate potential microbially mediated mercury methylation and volatilization pathways in polar marine environments. Our results identify the marine microaerophilic bacterium Nitrospina as a potential mercury methylator within sea ice. Anaerobic bacteria known to methylate mercury were notably absent from sea-ice metagenomes. We propose that Antarctic sea ice can harbour a microbial source of methylmercury in the Southern Ocean.

  14. The microbial ocean from genomes to biomes.

    PubMed

    DeLong, Edward F

    2009-05-14

    Numerically, microbial species dominate the oceans, yet their population dynamics, metabolic complexity and synergistic interactions remain largely uncharted. A full understanding of life in the ocean requires more than knowledge of marine microbial taxa and their genome sequences. The latest experimental techniques and analytical approaches can provide a fresh perspective on the biological interactions within marine ecosystems, aiding in the construction of predictive models that can interrelate microbial dynamics with the biogeochemical matter and energy fluxes that make up the ocean ecosystem.

  15. Understanding Microbial Communities: Function, Structure and Dynamics

    DTIC Science & Technology

    2015-02-11

    Park, NC 27709-2211 Conference grant, microbial ecology , biomathematics REPORT DOCUMENTATION PAGE 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 10...Wilmes. Challenges in Microbial Ecology : building predictive understanding, ISME Journal (06 2015) TOTAL: 1 Books Number of Manuscripts: Patents...a one day ’Open for business’ day which was attended by both industrial representatives interested in microbial ecology and academics. Final progress

  16. Estimating and comparing microbial diversity in the presence of sequencing errors

    PubMed Central

    Chiu, Chun-Huo

    2016-01-01

    Estimating and comparing microbial diversity are statistically challenging due to limited sampling and possible sequencing errors for low-frequency counts, producing spurious singletons. The inflated singleton count seriously affects statistical analysis and inferences about microbial diversity. Previous statistical approaches to tackle the sequencing errors generally require different parametric assumptions about the sampling model or about the functional form of frequency counts. Different parametric assumptions may lead to drastically different diversity estimates. We focus on nonparametric methods which are universally valid for all parametric assumptions and can be used to compare diversity across communities. We develop here a nonparametric estimator of the true singleton count to replace the spurious singleton count in all methods/approaches. Our estimator of the true singleton count is in terms of the frequency counts of doubletons, tripletons and quadrupletons, provided these three frequency counts are reliable. To quantify microbial alpha diversity for an individual community, we adopt the measure of Hill numbers (effective number of taxa) under a nonparametric framework. Hill numbers, parameterized by an order q that determines the measures’ emphasis on rare or common species, include taxa richness (q = 0), Shannon diversity (q = 1, the exponential of Shannon entropy), and Simpson diversity (q = 2, the inverse of Simpson index). A diversity profile which depicts the Hill number as a function of order q conveys all information contained in a taxa abundance distribution. Based on the estimated singleton count and the original non-singleton frequency counts, two statistical approaches (non-asymptotic and asymptotic) are developed to compare microbial diversity for multiple communities. (1) A non-asymptotic approach refers to the comparison of estimated diversities of standardized samples with a common finite sample size or sample completeness. This

  17. Estimating and comparing microbial diversity in the presence of sequencing errors.

    PubMed

    Chiu, Chun-Huo; Chao, Anne

    2016-01-01

    Estimating and comparing microbial diversity are statistically challenging due to limited sampling and possible sequencing errors for low-frequency counts, producing spurious singletons. The inflated singleton count seriously affects statistical analysis and inferences about microbial diversity. Previous statistical approaches to tackle the sequencing errors generally require different parametric assumptions about the sampling model or about the functional form of frequency counts. Different parametric assumptions may lead to drastically different diversity estimates. We focus on nonparametric methods which are universally valid for all parametric assumptions and can be used to compare diversity across communities. We develop here a nonparametric estimator of the true singleton count to replace the spurious singleton count in all methods/approaches. Our estimator of the true singleton count is in terms of the frequency counts of doubletons, tripletons and quadrupletons, provided these three frequency counts are reliable. To quantify microbial alpha diversity for an individual community, we adopt the measure of Hill numbers (effective number of taxa) under a nonparametric framework. Hill numbers, parameterized by an order q that determines the measures' emphasis on rare or common species, include taxa richness (q = 0), Shannon diversity (q = 1, the exponential of Shannon entropy), and Simpson diversity (q = 2, the inverse of Simpson index). A diversity profile which depicts the Hill number as a function of order q conveys all information contained in a taxa abundance distribution. Based on the estimated singleton count and the original non-singleton frequency counts, two statistical approaches (non-asymptotic and asymptotic) are developed to compare microbial diversity for multiple communities. (1) A non-asymptotic approach refers to the comparison of estimated diversities of standardized samples with a common finite sample size or sample completeness. This approach

  18. Tackling quantitation: a report on the annual Spring Workshop of the HUPO-PSI 28-30 March 2010, Seoul, South Korea.

    PubMed

    Orchard, Sandra; Jones, Andrew; Albar, Juan-Pablo; Cho, Sang Yun; Kwon, Kyung-Hoon; Lee, Cheolju; Hermjakob, Henning

    2010-09-01

    The annual Spring Workshop of the HUPO-PSI took place in Korea, where the Mass Spectrometry and Protein Separations groups joined forces to tackle the issue of the consistent reporting of quantitative proteomic data generated by mass-spectrometry-based technologies. A preliminary mzQuantML schema was drafted which, when completed and tested, will complement the existing mzIdentML schema for reporting protein identifications. The Molecular Interactions group concentrated on the implementations of the PSICQUIC (PSI Common Query InterfaCe) service that allows users to simultaneously query interaction data across multiple participating resources. Work was also undertaken to update the MIAPE guidelines, in response to feedback from the editors of a number of proteomic journals.

  19. A 2D domain decomposition, a customized immersed boundary method and a zest of numerical dissipation: a successful cocktail to tackle turbulence on HPC systems

    NASA Astrophysics Data System (ADS)

    Laizet, Sylvain; Lamballais, Eric; Vassilicos, J. Christos

    2015-11-01

    Incompact3d is a high-order flow solver dedicated to Direct and Large Eddy Simulations (DNS/LES) using High Performance Computing (HPC) systems which isdevoted to turbulent flows at the interface between academic research and upstream industrial R&D. It is originating from the University of Poitiers (France) and was developed there as well as, more recently, in the Turbulence, Mixing and Flow Control Group at Imperial College London (UK). This high-order flow solver can reconcile accuracy, efficiency, versatility and scalability using a simple Cartesian mesh and up to one million computational cores. The three key ingredients of this successful cocktail to tackle turbulence on HPC systemswill be given in this talkfollowed by various applications such as fractal-generated turbulence, gravity currents in an open basin, impinging jets on a heated plate and a micro-jet device to control a turbulent jet.

  20. A microbial perspective of human developmental biology.

    PubMed

    Charbonneau, Mark R; Blanton, Laura V; DiGiulio, Daniel B; Relman, David A; Lebrilla, Carlito B; Mills, David A; Gordon, Jeffrey I

    2016-07-07

    When most people think of human development, they tend to consider only human cells and organs. Yet there is another facet that involves human-associated microbial communities. A microbial perspective of human development provides opportunities to refine our definitions of healthy prenatal and postnatal growth and to develop innovative strategies for disease prevention and treatment. Given the dramatic changes in lifestyles and disease patterns that are occurring with globalization, we issue a call for the establishment of 'human microbial observatories' designed to examine microbial community development in birth cohorts representing populations with diverse anthropological characteristics, including those undergoing rapid change.

  1. Microbial Cretaceous park: biodiversity of microbial fossils entrapped in amber

    NASA Astrophysics Data System (ADS)

    Martín-González, Ana; Wierzchos, Jacek; Gutiérrez, Juan C.; Alonso, Jesús; Ascaso, Carmen

    2009-05-01

    Microorganisms are the most ancient cells on this planet and they include key phyla for understanding cell evolution and Earth history, but, unfortunately, their microbial records are scarce. Here, we present a critical review of fossilized prokaryotic and eukaryotic microorganisms entrapped in Cretaceous ambers (but not exclusively from this geological period) obtained from deposits worldwide. Microbiota in ambers are rather diverse and include bacteria, fungi, and protists. We comment on the most important microbial records from the last 25 years, although it is not an exhaustive bibliographic compilation. The most frequently reported eukaryotic microfossils are shells of amoebae and protists with a cell wall or a complex cortex. Likewise, diverse dormant stages (palmeloid forms, resting cysts, spores, etc.) are abundant in ambers. Besides, viral and protist pathogens have been identified inside insects entrapped in amber. The situation regarding filamentous bacteria and fungi is quite confusing because in some cases, the same record was identified consecutively as a member of these phylogenetically distant groups. To avoid these identification errors in the future, we propose to apply a more resolute microscopic and analytical method in amber studies. Also, we discuss the most recent findings about ancient DNA repair and bacterial survival in remote substrates, which support the real possibility of ancient DNA amplification and bacterial resuscitation from Cretaceous resins.

  2. Microbial Cretaceous park: biodiversity of microbial fossils entrapped in amber.

    PubMed

    Martín-González, Ana; Wierzchos, Jacek; Gutiérrez, Juan C; Alonso, Jesús; Ascaso, Carmen

    2009-05-01

    Microorganisms are the most ancient cells on this planet and they include key phyla for understanding cell evolution and Earth history, but, unfortunately, their microbial records are scarce. Here, we present a critical review of fossilized prokaryotic and eukaryotic microorganisms entrapped in Cretaceous ambers (but not exclusively from this geological period) obtained from deposits worldwide. Microbiota in ambers are rather diverse and include bacteria, fungi, and protists. We comment on the most important microbial records from the last 25 years, although it is not an exhaustive bibliographic compilation. The most frequently reported eukaryotic microfossils are shells of amoebae and protists with a cell wall or a complex cortex. Likewise, diverse dormant stages (palmeloid forms, resting cysts, spores, etc.) are abundant in ambers. Besides, viral and protist pathogens have been identified inside insects entrapped in amber. The situation regarding filamentous bacteria and fungi is quite confusing because in some cases, the same record was identified consecutively as a member of these phylogenetically distant groups. To avoid these identification errors in the future, we propose to apply a more resolute microscopic and analytical method in amber studies. Also, we discuss the most recent findings about ancient DNA repair and bacterial survival in remote substrates, which support the real possibility of ancient DNA amplification and bacterial resuscitation from Cretaceous resins.

  3. Flat laminated microbial mat communities

    NASA Astrophysics Data System (ADS)

    Franks, Jonathan; Stolz, John F.

    2009-10-01

    Flat laminated microbial mats are complex microbial ecosystems that inhabit a wide range of environments (e.g., caves, iron springs, thermal springs and pools, salt marshes, hypersaline ponds and lagoons, methane and petroleum seeps, sea mounts, deep sea vents, arctic dry valleys). Their community structure is defined by physical (e.g., light quantity and quality, temperature, density and pressure) and chemical (e.g., oxygen, oxidation/reduction potential, salinity, pH, available electron acceptors and donors, chemical species) parameters as well as species interactions. The main primary producers may be photoautotrophs (e.g., cyanobacteria, purple phototrophs, green phototrophs) or chemolithoautophs (e.g., colorless sulfur oxidizing bacteria). Anaerobic phototrophy may predominate in organic rich environments that support high rates of respiration. These communities are dynamic systems exhibiting both spatial and temporal heterogeneity. They are characterized by steep gradients with microenvironments on the submillimeter scale. Diel oscillations in the physical-chemical profile (e.g., oxygen, hydrogen sulfide, pH) and species distribution are typical for phototroph-dominated communities. Flat laminated microbial mats are often sites of robust biogeochemical cycling. In addition to well-established modes of metabolism for phototrophy (oxygenic and non-oxygenic), respiration (both aerobic and anaerobic), and fermentation, novel energetic pathways have been discovered (e.g., nitrate reduction couple to the oxidation of ammonia, sulfur, or arsenite). The application of culture-independent techniques (e.g., 16S rRNA clonal libraries, metagenomics), continue to expand our understanding of species composition and metabolic functions of these complex ecosystems.

  4. Far and Wide - Microbial Bebop

    SciTech Connect

    Peter Larsen

    2012-10-01

    This musical composition was created from data of microbes (bacteria, algae and other microorganisms) sampled in the English Channel. Argonne National Laboratory biologist Peter Larsen created the songs as a unique way to present and comprehend large datasets. Microbial species of the Order Rickettsiales, such as the highly abundant, free-living planktonic species Pelagibacter ubique, are typical highly abundant taxa in L4 Station data. Its relative abundance in the microbial community at L4 Station follows a distinctive seasonal pattern. In this composition, there are two chords per measure, generated from photosynthetically active radiation measurements and temperature. The melody of each measure is six notes that describe the relative abundance of the Order Rickettsiales. The first note of each measure is from the relative abundance at a time point. The next five notes of a measure follow one of the following patterns: a continuous rise in pitch, a continuous drop in pitch, a rise then drop in pitch, or a drop then rise in pitch. These patterns are matched to the relative abundance of Rickettsiales at the given time point, relative to the previous and subsequent time points. The pattern of notes in a measure is mapped to the relative abundance of Rickettsiales with fewer rests per measure indicating higher abundance. For time points at which Rickettsiales was the most abundant microbial taxa, the corresponding measure is highlighted with a cymbal crash. More information at http://www.anl.gov/articles/songs-key... Image: Diatoms under a microscope: These tiny phytoplankton are encased within a silicate cell wall. Credit: Prof. Gordon T. Taylor, Stony Brook University

  5. Designing the Microbial Research Commons

    SciTech Connect

    Uhlir, Paul F.

    2011-10-01

    Recent decades have witnessed an ever-increasing range and volume of digital data. All elements of the pillars of science--whether observation, experiment, or theory and modeling--are being transformed by the continuous cycle of generation, dissemination, and use of factual information. This is even more so in terms of the re-using and re-purposing of digital scientific data beyond the original intent of the data collectors, often with dramatic results. We all know about the potential benefits and impacts of digital data, but we are also aware of the barriers, the challenges in maximizing the access, and use of such data. There is thus a need to think about how a data infrastructure can enhance capabilities for finding, using, and integrating information to accelerate discovery and innovation. How can we best implement an accessible, interoperable digital environment so that the data can be repeatedly used by a wide variety of users in different settings and with different applications? With this objective: to use the microbial communities and microbial data, literature, and the research materials themselves as a test case, the Board on Research Data and Information held an International Symposium on Designing the Microbial Research Commons at the National Academy of Sciences in Washington, DC on 8-9 October 2009. The symposium addressed topics such as models to lower the transaction costs and support access to and use of microbiological materials and digital resources from the perspective of publicly funded research, public-private interactions, and developing country concerns. The overall goal of the symposium was to stimulate more research and implementation of improved legal and institutional models for publicly funded research in microbiology.

  6. Microbial enhanced oil recovery research

    SciTech Connect

    Sharma, M.M.; Georgiou, G.

    1990-03-01

    In the previous quarterly report we described the criteria for selecting a microorganism for Microbial Enhanced Oil Recovery studies. After careful consideration we chose Bacillus licheniformis JF-2 because of its ability to withstand reservoir conditions and the production of a surface active lipopeptide. Detailed experiments were conducted in stirred tank fermenters equipped with pH control and constant sparging of air or, in the case of anaerobic experiments, O{sub 2}-free nitrogen. The effect of temperature and pH on biomass production, glucose consumption and interfacial tension against decane were determined for both aerobic and anaerobic conditions. 5 figs., 2 tabs.

  7. 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

  8. Microbial production of primary metabolites

    NASA Astrophysics Data System (ADS)

    Demain, Arnold L.

    1980-12-01

    Microbial production of primary metabolites contributes significantly to the quality of life. Through fermentation, microorganisms growing on inexpensive carbon sources can produce valuable products such as amino acids, nucleotides, organic acids, and vitamins which can be added to food to enhance its flavor or increase its nutritive value. The contribution of microorganisms will go well beyond the food industry with the renewed interest in solvent fermentations. Microorganisms have the potential to provide many petroleum-derived products as well as the ethanol necessary for liquid fuel. The role of primary metabolites and the microbes which produce them will certainly increase in importance.

  9. Microbial oxidation of dimethylnaphthalene isomers

    SciTech Connect

    Miyachi, Nobuya; Tanaka, Tohru; Suzuki, Takaya; Hotta, Yasushi ); Omori, Toshio )

    1993-05-01

    Few studies have focused on the microbial oxidation and metabolism of dimethylnaphthalenes (DMNs), which are supplied from the light oil fraction of crude oil. This report describes the isolation of 2,6-DMN-utilizing bacteria, the identification of the isolates (Alcaligenes sp. strain D-59, Pseudomonas sp. strains D-87 and D-186), the accumulation of 2,6-naphthalene dicarboxylic acid (NDCA) from 2,6-DMN, the identification of some metabolic intermediates of 2,6-DMN, and a proposal of a metabolic pathway of 2,6-DMN. 11 refs., 2 figs.

  10. Hydrogen production from microbial strains

    DOEpatents

    Harwood, Caroline S; Rey, Federico E

    2012-09-18

    The present invention is directed to a method of screening microbe strains capable of generating hydrogen. This method involves inoculating one or more microbes in a sample containing cell culture medium to form an inoculated culture medium. The inoculated culture medium is then incubated under hydrogen producing conditions. Once incubating causes the inoculated culture medium to produce hydrogen, microbes in the culture medium are identified as candidate microbe strains capable of generating hydrogen. Methods of producing hydrogen using one or more of the microbial strains identified as well as the hydrogen producing strains themselves are also disclosed.

  11. Microbial profile modification with spores

    SciTech Connect

    Bae, J.H.; Chambers, K.T.; Lee, H.O.

    1996-08-01

    To overcome the shortcomings of conventional, near-wellbore profile modification methods, a microbial profile modification (MPM) method with spores was investigated. A halotolerant, spore-forming mesophile was isolated and characterized. These biopolymer-producing spores propagate easily in Berea cores with permeabilities more than about 500 md. With a specifically formulated nutrient package, they are readily germinated and produce biofilm, which reduces the permeability of the rock. The depth of penetration and the degree of permeability reduction can be controlled by varying injection schemes.

  12. Method for analyzing microbial communities

    DOEpatents

    Zhou, Jizhong [Oak Ridge, TN; Wu, Liyou [Oak Ridge, TN

    2010-07-20

    The present invention provides a method for quantitatively analyzing microbial genes, species, or strains in a sample that contains at least two species or strains of microorganisms. The method involves using an isothermal DNA polymerase to randomly and representatively amplify genomic DNA of the microorganisms in the sample, hybridizing the resultant polynucleotide amplification product to a polynucleotide microarray that can differentiate different genes, species, or strains of microorganisms of interest, and measuring hybridization signals on the microarray to quantify the genes, species, or strains of interest.

  13. Microbial Forensics: A Scientific Assessment

    SciTech Connect

    Keim, Paul

    2003-02-17

    Microorganisms have been used as weapons in criminal acts, most recently highlighted by the terrorist attack using anthrax in the fall of 2001. Although such ''biocrimes'' are few compared with other crimes, these acts raise questions about the ability to provide forensic evidence for criminal prosecution that can be used to identify the source of the microorganisms used as a weapon and, more importantly, the perpetrator of the crime. Microbiologists traditionally investigate the sources of microorganisms in epidemiological investigations, but rarely have been asked to assist in criminal investigations. A colloquium was convened by the American Academy of Microbiology in Burlington, Vermont, on June 7-9, 2002, in which 25 interdisciplinary, expert scientists representing evolutionary microbiology, ecology, genomics, genetics, bioinformatics, forensics, chemistry, and clinical microbiology, deliberated on issues in microbial forensics. The colloquium's purpose was to consider issues relating to microbial forensics, which included a detailed identification of a microorganism used in a bioattack and analysis of such a microorganism and related materials to identify its forensically meaningful source--the perpetrators of the bioattack. The colloquium examined the application of microbial forensics to assist in resolving biocrimes with a focus on what research and education are needed to facilitate the use of microbial forensics in criminal investigations and the subsequent prosecution of biocrimes, including acts of bioterrorism. First responders must consider forensic issues, such as proper collection of samples to allow for optimal laboratory testing, along with maintaining a chain of custody that will support eventual prosecution. Because a biocrime may not be immediately apparent, a linkage must be made between routine diagnosis, epidemiological investigation, and criminal investigation. There is a need for establishing standard operating procedures and training to

  14. Microbial biodegradation of polyaromatic hydrocarbons.

    PubMed

    Peng, Ri-He; Xiong, Ai-Sheng; Xue, Yong; Fu, Xiao-Yan; Gao, Feng; Zhao, Wei; Tian, Yong-Sheng; Yao, Quan-Hong

    2008-11-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread in various ecosystems and are pollutants of great concern due to their potential toxicity, mutagenicity and carcinogenicity. Because of their hydrophobic nature, most PAHs bind to particulates in soil and sediments, rendering them less available for biological uptake. Microbial degradation represents the major mechanism responsible for the ecological recovery of PAH-contaminated sites. The goal of this review is to provide an outline of the current knowledge of microbial PAH catabolism. In the past decade, the genetic regulation of the pathway involved in naphthalene degradation by different gram-negative and gram-positive bacteria was studied in great detail. Based on both genomic and proteomic data, a deeper understanding of some high-molecular-weight PAH degradation pathways in bacteria was provided. The ability of nonligninolytic and ligninolytic fungi to transform or metabolize PAH pollutants has received considerable attention, and the biochemical principles underlying the degradation of PAHs were examined. In addition, this review summarizes the information known about the biochemical processes that determine the fate of the individual components of PAH mixtures in polluted ecosystems. A deeper understanding of the microorganism-mediated mechanisms of catalysis of PAHs will facilitate the development of new methods to enhance the bioremediation of PAH-contaminated sites.

  15. Microbial Senses and Ion Channels

    NASA Astrophysics Data System (ADS)

    Kung, Ching; Zhou, Xin-Liang; Su, Zhen-Wei; Haynes, W. John; Loukin, Sephan H.; Saimi, Yoshiro

    The complexity of animals and plants is due largely to cellular arrangement. The structures and activities of macromolecules had, however, evolved in early microbes long before the appearance of this complexity. Among such molecules are those that sense light, heat, force, water, and ligands. Though historically and didactically associated with the nervous system, ion channels also have deep evolutionary roots. For example, force sensing with channels, which likely began as water sensing through membrane stretch generated by osmotic pressure, must be ancient and is universal in extant species. Extant microbial species, such as the model bacterium Escherichia coli and yeast Saccharomyces cerevisiae, are equipped with stretch-activated channels. The ion channel proteins MscL and MscS show clearly that these bacterial channels receive stretch forces from the lipid bilayer. TRPY1, the mechanosensitive channel in yeast, is being developed towards a similar basic understanding of channels of the TRP (transientreceptor- potential) superfamily. TRPY1 resides in the vacuolar membrane and releases Ca2+ from the vacuole to the cytoplasm upon hyperosmotic shock. Unlike in most TRP preparations from animals, the mechanosensitivity of TRPY1 can be examined directly under patch clamp in either whole-vacuole mode or excised patch mode. The combination of direct biophysical examination in vitro with powerful microbial genetics in vivo should complement the study of mechanosensations of complex animals and plants.

  16. Microbial production of fatty alcohols.

    PubMed

    Fillet, Sandy; Adrio, José L

    2016-09-01

    Fatty alcohols have numerous commercial applications, including their use as lubricants, surfactants, solvents, emulsifiers, plasticizers, emollients, thickeners, and even fuels. Fatty alcohols are currently produced by catalytic hydrogenation of fatty acids from plant oils or animal fats. Microbial production of fatty alcohols may be a more direct and environmentally-friendly strategy since production is carried out by heterologous enzymes, called fatty acyl-CoA reductases, able to reduce different acyl-CoA molecules to their corresponding primary alcohols. Successful examples of metabolic engineering have been reported in Saccharomyces cerevisiae and Escherichia coli in which the production of fatty alcohols ranged from 1.2 to 1.9 g/L, respectively. Due to their metabolic advantages, oleaginous yeasts are considered the best hosts for production of fatty acid-derived chemicals. Some of these species can naturally produce, under specific growth conditions, lipids at high titers (>50 g/L) and therefore provide large amounts of fatty acyl-CoAs or fatty acids as precursors. Very recently, taking advantage of such features, over 8 g/L of C16-C18 fatty alcohols have been produced in Rhodosporidium toruloides. In this review we summarize the different metabolic engineering strategies, hosts and cultivation conditions used to date. We also point out some future trends and challenges for the microbial production of fatty alcohols.

  17. Microbial hydrolysis of steviol glycosides.

    PubMed

    Renwick, A G; Tarka, S M

    2008-07-01

    A review of the role of gut microbiota in the metabolism of the steviol glycosides, stevioside and rebaudioside A, indicates that they are not absorbed intact but undergo hydrolysis by the intestinal microflora to steviol. Steviol is not metabolized by the intestinal flora and is absorbed from the intestine. The rate of hydrolysis for stevioside is greater than for rebaudioside A. Recent studies using mass spectrometry have shown that steviol-16,17-epoxide is not a microbial metabolite of steviol glycosides. Bacteroides species are primarily responsible for hydrolysis via their beta-glucosidase activity. Fecal incubation studies with both human and animal mixed flora provide similar results, and this indicates that the rat is an appropriate model for studies on steviol glycosides. Given the similarity in the microbial metabolism of stevioside and rebaudioside A with the formation of steviol as the single hydrolysis product that is absorbed from the intestinal tract, the toxicological data on stevioside are relevant to the risk assessment of rebaudioside A.

  18. Manipulation of Biofilm Microbial Ecology

    SciTech Connect

    White, D.C.; Palmer, R.J., Jr.; Zinn, M.; Smith, C.A.; Burkhalter, R.; Macnaughton, S.J.; Whitaker, K.W.; Kirkegaard, R.D.

    1998-08-15

    The biofilm mode of growth provides such significant advantages to the members of the consortium that most organisms in important habitats are found in biofilms. The study of factors that allow manipulation of biofilm microbes in the biofilm growth state requires that reproducible biofilms be generated. The most effective monitoring of biofilm formation, succession and desaturation is with on-line monitoring of microbial biofilms with flowcell for direct observation. The biofilm growth state incorporates a second important factor, the heterogeneity in distribution in time and space of the component members of the biofilm consortium. This heterogeneity is reflected not only in the cellular distribution but in the metabolic activity within a population of cells. Activity and cellular distribution can be mapped in four dimensions with confocal microscopy, and function can be ascertained by genetically manipulated reporter functions for specific genes or by vital stains. The methodology for understanding the microbial ecology of biofilms is now much more readily available and the capacity to manipulate biofilms is becoming an important feature of biotechnology.

  19. Manipulatiaon of Biofilm Microbial Ecology

    SciTech Connect

    Burkhalter, R.; Macnaughton, S.J.; Palmer, R.J.; Smith, C.A.; Whitaker, K.W.; White, D.C.; Zinn, M.; kirkegaard, R.

    1998-08-09

    The Biofilm mode of growth provides such significant advantages to the members of the consortium that most organisms in important habitats are found in biofilms. The study of factors that allow manipulation of biofilm microbes in the biofilm growth state requires that reproducible biofilms by generated. The most effective monitoring of biofilm formation, succession and desquamation is with on-line monitoring of microbial biofilms with flowcell for direct observation. The biofilm growth state incorporates a second important factor, the heterogeneity in the distribution in time and space of the component members of the biofilm consortium. This heterogeneity is reflected not only in the cellular distribution but in the metabolic activity within a population of cells. Activity and cellular distribution can be mapped in four dimensions with confocal microscopy, and function can be ascertained by genetically manipulated reporter functions for specific genes or by vital stains. The methodology for understanding the microbial ecology of biofilms is now much more readily available and the capacity to manipulate biofilms is becoming an important feature of biotechnology.

  20. Blues for Elle - Microbial Bebop

    SciTech Connect

    Peter Larsen

    2012-10-01

    This musical composition was created from data of microbes - bacteria, algae and other microorganisms - sampled in the English Channel. (Above, the USS Winston S. Churchill traverses the English Channel.) Argonne National Laboratory biologist Peter Larsen created the songs as a unique way to present and comprehend large datasets. Some marine microbial taxa are most often present in the L4 Station community at very low abundance, but occasionally become highly dominant community members. To link these microbial blooms to relevant physical parameters, the chords in this composition are derived from changes in chlorophyll A concentrations and salinity. The melody for each measure is derived from the relative abundances of typically rare taxa that were observed to occasionally bloom to higher abundance in the following order: Cyanobacteria, Vibrionales, Opitulates, Pseudomondales, Rhizobiales, Bacillales, Oceanospirallales, and Sphingomonadales. More information at http://www.anl.gov/articles/songs-key... Photo: USS Winston S. Churchill and Royal Navy HMS Cumberland transit the English Channel, courtesy U.S. Navy (http://www.flickr.com/photos/usnavy/5...)

  1. Microbial Extremophiles in Evolutionary Aspect

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.

    2007-01-01

    The microflora of the cryosphere of planet Earth provides the best analogs for life forms that might be found in the permafrost or polar ice caps of Mars, near the surface of the cometary nuclei, or in the liquid water beneath the ice crusts of icy moons of Jupiter and Saturn. For astrobiology the focus on the study alkaliphilic microorganisms was enhanced by the findings of abundant carbonates and carbonate globules rimmed with possibly biogenic magnetites in association with the putative microfossils in the ALH84001 meteorite. Although the ALH84001 "nanofossils" were to small and simple to be unambiguously recognized as biogenic, they stimulated Astrobiology research and studies of microbial extremophiles and biomarkers in ancient rocks and meteorites. Recent studies of CI and CM carbonaceous meteorites have resulted in the detection of the well-preserved mineralized remains of coccoidal and" filamentous microorganisms in cyanobacterial mats. Energy Dispersive X-ray Analysis has shown anomalous biogenic element ratios clearly indicating they are not recent biological contaminants. This paper reviews microbial extremophiles in context of their significance to Astrobiology and the evolution of life. Extremophilic microorganisms on Earth are models for life that might endure high radiation environments in the ice near the surface of comets or on the icy moons of Jupiter and Saturn and in the seafloor deep beneath the icy crusts of Europa and Enceladus.

  2. Molecular Survey of Concrete Biofilm Microbial Communities

    EPA Science Inventory

    Although several studies have shown that bacteria can deteriorate concrete structures, there is very little information on the composition of concrete microbial communities. To this end, we studied different microbial communities associated with concrete biofilms using 16S rRNA g...

  3. Microbial Biosensors for Selective Detection of Disaccharides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seven microbial strains were screened for their ability to detect disaccharides as components of Clark-type oxygen biosensors. Sensors responded to varying degrees to maltose, cellobiose, sucrose, and melibiose, but none responded strongly to lactose. Although microbial sensors are relatively nons...

  4. Method Analysis of Microbial Resistant Gypsum Products

    EPA Science Inventory

    Abstract: Several commercially available gypsum products are marketed as microbial-resistant. During previous test method research on a microbial resistant gypsum wallboard study, a common theme from both stakeholders and product vendors was the need for a unified and accepted m...

  5. Production Methods for Microbial Biocontrol Agents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A critical constraint to the commercial use of microbial biopesticides is the development of an economic production process. The production process must be cost-effective and yield a microbial propagule that is stable and efficacious under field conditions. Currently, the commercial production of ...

  6. 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.

  7. Uses of antimicrobial genes from microbial genome

    DOEpatents

    Sorek, Rotem; Rubin, Edward M.

    2013-08-20

    We describe a method for mining microbial genomes to discover antimicrobial genes and proteins having broad spectrum of activity. Also described are antimicrobial genes and their expression products from various microbial genomes that were found using this method. The products of such genes can be used as antimicrobial agents or as tools for molecular biology.

  8. Comparative molecular analysis of endoevaporitic microbial communities.

    PubMed

    Sahl, Jason W; Pace, Norman R; Spear, John R

    2008-10-01

    A phylogenetic comparison of microbial communities in hypersaline evaporites was conducted on crusts from Guerrero Negro, Mexico, and Lindsey Lake, New Mexico, using culture-independent rRNA gene sequence analysis. Many sequences were shared between evaporites, which suggests that similar environments select for specific microbial lineages from a global metacommunity.

  9. Fundamentals of Microbial Community Resistance and Resilience

    PubMed Central

    Shade, Ashley; Peter, Hannes; Allison, Steven D.; Baho, Didier L.; Berga, Mercè; Bürgmann, Helmut; Huber, David H.; Langenheder, Silke; Lennon, Jay T.; Martiny, Jennifer B. H.; Matulich, Kristin L.; Schmidt, Thomas M.; Handelsman, Jo

    2012-01-01

    Microbial communities are at the heart of all ecosystems, and yet microbial community behavior in disturbed environments remains difficult to measure and predict. Understanding the drivers of microbial community stability, including resistance (insensitivity to disturbance) and resilience (the rate of recovery after disturbance) is important for predicting community response to disturbance. Here, we provide an overview of the concepts of stability that are relevant for microbial communities. First, we highlight insights from ecology that are useful for defining and measuring stability. To determine whether general disturbance responses exist for microbial communities, we next examine representative studies from the literature that investigated community responses to press (long-term) and pulse (short-term) disturbances in a variety of habitats. Then we discuss the biological features of individual microorganisms, of microbial populations, and of microbial communities that may govern overall community stability. We conclude with thoughts about the unique insights that systems perspectives – informed by meta-omics data – may provide about microbial community stability. PMID:23267351

  10. Microbial inoculant carrier for pesticide degradation

    SciTech Connect

    Zhixing, Y.; Velagaleti, R.; Gorman, M.

    1995-12-31

    Biological degradation of pesticides may be enhanced by using a suitable carrier that sustains microbial growth. The char matrix (TRB Char) was evaluated as a biocarrier, and is produced by three sequential cocurrent gasifications of coal. The nature of TRB Char and the large pores provides an ideal matrix for mixing, drying, and retaining liquid wastes. The macropore structure of TRB Char is also ideal for microbial growth. Plate counts were conducted to monitor the extent of microbial growth following 20 and 504 hours of growth. Additionally, electron micrograph scans showed location of microbial growth on the char particle. By 21 days 10{sup 8} colony forming units per gram of bacteria had grown. The electron micrographs showed that the macropore structure of TRB Char is an ideal shelter for microbial growth throughout the char particle. TRB Char could serve as a biocarrier for pesticide degradation.

  11. Microbial diversity drives multifunctionality in terrestrial ecosystems.

    PubMed

    Delgado-Baquerizo, Manuel; Maestre, Fernando T; Reich, Peter B; Jeffries, Thomas C; Gaitan, Juan J; Encinar, Daniel; Berdugo, Miguel; Campbell, Colin D; Singh, Brajesh K

    2016-01-28

    Despite the importance of microbial communities for ecosystem services and human welfare, the relationship between microbial diversity and multiple ecosystem functions and services (that is, multifunctionality) at the global scale has yet to be evaluated. Here we use two independent, large-scale databases with contrasting geographic coverage (from 78 global drylands and from 179 locations across Scotland, respectively), and report that soil microbial diversity positively relates to multifunctionality in terrestrial ecosystems. The direct positive effects of microbial diversity were maintained even when accounting simultaneously for multiple multifunctionality drivers (climate, soil abiotic factors and spatial predictors). Our findings provide empirical evidence that any loss in microbial diversity will likely reduce multifunctionality, negatively impacting the provision of services such as climate regulation, soil fertility and food and fibre production by terrestrial ecosystems.

  12. Microarray Applications in Microbial Ecology Research.

    SciTech Connect

    Gentry, T.; Schadt, C.; Zhou, J.

    2006-04-06

    Microarray technology has the unparalleled potential tosimultaneously determine the dynamics and/or activities of most, if notall, of the microbial populations in complex environments such as soilsand sediments. Researchers have developed several types of arrays thatcharacterize the microbial populations in these samples based on theirphylogenetic relatedness or functional genomic content. Several recentstudies have used these microarrays to investigate ecological issues;however, most have only analyzed a limited number of samples withrelatively few experiments utilizing the full high-throughput potentialof microarray analysis. This is due in part to the unique analyticalchallenges that these samples present with regard to sensitivity,specificity, quantitation, and data analysis. This review discussesspecific applications of microarrays to microbial ecology research alongwith some of the latest studies addressing the difficulties encounteredduring analysis of complex microbial communities within environmentalsamples. With continued development, microarray technology may ultimatelyachieve its potential for comprehensive, high-throughput characterizationof microbial populations in near real-time.

  13. DIAGNOSTIC AND PROGNOSTIC MICROBIAL BIOMARKERS IN IBD

    PubMed Central

    Dubinsky, Marla; Braun, Jonathan

    2015-01-01

    The microbiome plays multi-faceted roles in the pathogenesis of inflammatory bowel diseases (IBD). Accordingly, the clinical challenge of patient heterogeneity in disease phenotype and response to treatment should in part be addressed by biomarkers that detect the host response to microbiota, and the levels of microbial taxa and products eliciting the host response in susceptible individuals. Molecular analysis has revealed much evidence for microbial taxonomic membership and microbial products in association with IBD, but their utility as clinical biomarkers is still in its infancy. A rich area of progress has been the development and validation of host serologic microbial biomarkers, which have achieved a distinctive position in the diagnosis and prognosis in IBD, and as a template for defining other categories of microbial biomarkers in disease state and phenotype. PMID:26284597

  14. Microbial biofilms: biosurfactants as antibiofilm agents.

    PubMed

    Banat, Ibrahim M; De Rienzo, Mayri A Díaz; Quinn, Gerry A

    2014-12-01

    Current microbial inhibition strategies based on planktonic bacterial physiology have been known to have limited efficacy on the growth of biofilm communities. This problem can be exacerbated by the emergence of increasingly resistant clinical strains. All aspects of biofilm measurement, monitoring, dispersal, control, and inhibition are becoming issues of increasing importance. Biosurfactants have merited renewed interest in both clinical and hygienic sectors due to their potential to disperse microbial biofilms in addition to many other advantages. The dispersal properties of biosurfactants have been shown to rival those of conventional inhibitory agents against bacterial and yeast biofilms. This makes them suitable candidates for use in new generations of microbial dispersal agents and for use as adjuvants for existing microbial suppression or eradication strategies. In this review, we explore aspects of biofilm characteristics and examine the contribution of biologically derived surface-active agents (biosurfactants) to the disruption or inhibition of microbial biofilms.

  15. 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.

  16. Microbial diversity drives multifunctionality in terrestrial ecosystems

    PubMed Central

    Delgado-Baquerizo, Manuel; Maestre, Fernando T.; Reich, Peter B.; Jeffries, Thomas C.; Gaitan, Juan J.; Encinar, Daniel; Berdugo, Miguel; Campbell, Colin D.; Singh, Brajesh K.

    2016-01-01

    Despite the importance of microbial communities for ecosystem services and human welfare, the relationship between microbial diversity and multiple ecosystem functions and services (that is, multifunctionality) at the global scale has yet to be evaluated. Here we use two independent, large-scale databases with contrasting geographic coverage (from 78 global drylands and from 179 locations across Scotland, respectively), and report that soil microbial diversity positively relates to multifunctionality in terrestrial ecosystems. The direct positive effects of microbial diversity were maintained even when accounting simultaneously for multiple multifunctionality drivers (climate, soil abiotic factors and spatial predictors). Our findings provide empirical evidence that any loss in microbial diversity will likely reduce multifunctionality, negatively impacting the provision of services such as climate regulation, soil fertility and food and fibre production by terrestrial ecosystems. PMID:26817514

  17. Microbial Burden Approach : New Monitoring Approach for Measuring Microbial Burden

    NASA Technical Reports Server (NTRS)

    Venkateswaran, Kasthuri; Vaishampayan, Parag; Barmatz, Martin

    2013-01-01

    Advantages of new approach for differentiating live cells/ spores from dead cells/spores. Four examples of Salmonella outbreaks leading to costly destruction of dairy products. List of possible collaboration activities between JPL and other industries (for future discussion). Limitations of traditional microbial monitoring approaches. Introduction to new approach for rapid measurement of viable (live) bacterial cells/spores and its areas of application. Detailed example for determining live spores using new approach (similar procedure for determining live cells). JPL has developed a patented approach for measuring amount of live and dead cells/spores. This novel "molecular" method takes less than 5 to 7 hrs. compared to the seven days required using conventional techniques. Conventional "molecular" techniques can not discriminate live cells/spores among dead cells/spores. The JPL-developed novel method eliminates false positive results obtained from conventional "molecular" techniques that lead to unnecessary delay in the processing and to unnecessary destruction of food products.

  18. Microbial populations in contaminant plumes

    NASA Astrophysics Data System (ADS)

    Haack, Sheridan K.; Bekins, Barbara A.

    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. La biodégradation efficace des polluants souterrains requiert deux éléments: des populations microbiennes possédant les aptitudes nécessaires à la dégradation, et des conditions géochimiques et hydrologiques souterraines favorables. Des contraintes pratiques sur la conception et l'interprétation des expériences à la fois en microbiologie et en hydrogéologie ont conduit à une connaissance limitée des interactions entre les

  19. Tackling inequalities in obesity: a protocol for a systematic review of the effectiveness of public health interventions at reducing socioeconomic inequalities in obesity among adults

    PubMed Central

    2013-01-01

    Background Socioeconomic inequalities in obesity and associated risk factors for obesity are widening throughout developed countries worldwide. Tackling obesity is high on the public health agenda both in the United Kingdom and internationally. However, what works in terms of interventions that are able to reduce inequalities in obesity is lacking. Methods/Design The review will examine public health interventions at the individual, community and societal level that might reduce inequalities in obesity among adults aged 18 years and over, in any setting and in any country. The following electronic databases will be searched: MEDLINE, EMBASE, CINAHL, PsycINFO, Social Science Citation Index, ASSIA, IBSS, Sociological Abstracts, and the NHS Economic Evaluation Database. Database searches will be supplemented with website and gray literature searches. No studies will be excluded based on language, country or publication date. Randomized and non-randomized controlled trials, prospective and retrospective cohort studies (with/without control groups) and prospective repeat cross-sectional studies (with/without control groups) that have a primary outcome that is a proxy for body fatness and have examined differential effects with regard to socioeconomic status (education, income, occupation, social class, deprivation, poverty) or where the intervention has been targeted specifically at disadvantaged groups or deprived areas will be included. Study inclusion, data extraction and quality appraisal will be conducted by two reviewers. Meta-analysis and narrative synthesis will be conducted. The main analysis will examine the effects of 1) individual, 2) community and 3) societal level public health interventions on socioeconomic inequalities in adult obesity. Interventions will be characterized by their level of action and their approach to tackling inequalities. Contextual information on how such public health interventions are organized, implemented and delivered will also

  20. 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.

  1. Microbial biodiversity of the atmosphere

    NASA Astrophysics Data System (ADS)

    Klein, Ann Maureen

    Microorganisms are critical to the functioning of terrestrial and aquatic ecosystems and may also play a role in the functioning of the atmosphere. However, little is known about the diversity and function of microorganisms in the atmosphere. To investigate the forces driving the assembly of bacterial microbial communities in the atmosphere, I measured temporal variation in bacterial diversity and composition over diurnal and inter-day time scales. Results suggest that bacterial communities in the atmosphere markedly vary over diurnal time scales and are likely structured by inputs from both local terrestrial and long-distance sources. To assess the potential functions of bacteria and fungi in the atmosphere, I characterized total and potentially active communities using both RNA- and DNA-based data. Results suggest there are metabolically active microorganisms in the atmosphere that may affect atmospheric functions including precipitation development and carbon cycling. This dissertation includes previously published and unpublished co-authored material.

  2. Microbial reduction of iron ore

    DOEpatents

    Hoffmann, M.R.; Arnold, R.G.; Stephanopoulos, G.

    1989-11-14

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry. 11 figs.

  3. Microbial reduction of iron ore

    DOEpatents

    Hoffmann, Michael R.; Arnold, Robert G.; Stephanopoulos, Gregory

    1989-01-01

    A process is provided for reducing iron ore by treatment with microorganisms which comprises forming an aqueous mixture of iron ore, microorganisms operable for reducing the ferric iron of the iron ore to ferrous iron, and a substrate operable as an energy source for the microbial reduction; and maintaining the aqueous mixture for a period of time and under conditions operable to effect the reduction of the ore. Preferably the microorganism is Pseudomonas sp. 200 and the reduction conducted anaerobically with a domestic wastewater as the substrate. An aqueous solution containing soluble ferrous iron can be separated from the reacted mixture, treated with a base to precipitate ferrous hydroxide which can then be recovered as a concentrated slurry.

  4. Microbial diversity of cellulose hydrolysis.

    PubMed

    Wilson, David B

    2011-06-01

    Enzymatic hydrolysis of cellulose by microorganisms is a key step in the global carbon cycle. Despite its abundance only a small percentage of microorganisms can degrade cellulose, probably because it is present in recalcitrant cell walls. There are at least five distinct mechanisms used by different microorganisms to degrade cellulose all of which involve cellulases. Cellulolytic organisms and cellulases are extremely diverse possibly because their natural substrates, plant cell walls, are very diverse. At this time the microbial ecology of cellulose degradation in any environment is still not clearly understood even though there is a great deal of information available about the bovine rumen. Two major problems that limit our understanding of this area are the vast diversity of organisms present in most cellulose degrading environments and the inability to culture most of them.

  5. Well having inhibited microbial growth

    DOEpatents

    Lee, Brady D.; Dooley, Kirk J.

    2006-08-15

    The invention includes methods of inhibiting microbial growth in a well. A packing material containing a mixture of a first material and an antimicrobial agent is provided to at least partially fill a well bore. One or more access tubes are provided in an annular space around a casing within the well bore. The access tubes have a first terminal opening located at or above a ground surface and have a length that extends from the first terminal opening at least part of the depth of the well bore. The access tubes have a second terminal opening located within the well bore. An antimicrobial material is supplied into the well bore through the first terminal opening of the access tubes. The invention also includes well constructs.

  6. Microbial processes in frozen food

    NASA Astrophysics Data System (ADS)

    Geiges, O.

    Deep freezing of food and storage at -19 degC is a standard conservation procedure in food technology. The lower limit of growth of bacteria in food is from about -5 degC to about -8 degC, whereas the reproduction limit of yeasts is 2 to 3 degC lower. Storage temperatures above -10 degC should therefore not be used. At -18 degC, a commonly used storage temperature, no growth of microorganisms will occur. The microorganisms mainly found at the lower growth limit are Pseudomonas sp. and basidiomycete yeasts. The reduction in the number of microorganisms due to freezing, storage, and thawing is not of practical importance. Microbial enzymes, in particular lipases and proteases, are still active at -18 degC. Therefore, the quality of raw products and good hygiene at the production site are most important.

  7. Microbial enhanced oil recovery (MEOR).

    PubMed

    Brown, Lewis R

    2010-06-01

    Two-thirds of the oil ever found is still in the ground even after primary and secondary production. Microbial enhanced oil recovery (MEOR) is one of the tertiary methods purported to increase oil recovery. Since 1946 more than 400 patents on MEOR have been issued, but none has gained acceptance by the oil industry. Most of the literature on MEOR is from laboratory experiments or from field trials of insufficient duration or that lack convincing proof of the process. Several authors have made recommendations required to establish MEOR as a viable method to enhance oil recovery, and until these tests are performed, MEOR will remain an unproven concept rather than a highly desirable reality.

  8. Microbial Check Valve for Shuttle

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.; Putnam, D. F.; Sauer, R. L.

    1978-01-01

    The Microbial Check Valve (MCV) is a device developed for the Space Shuttle that prevents the transfer of viable microorganisms within water systems. The device is essentially a bed of resin material, impregnated with iodine, that kills microorganisms on contact. It prevents the cross-contamination of microorganisms from a nonpotable system into the potable water system when these systems are interconnected. In this regard, the function of the device is similar to that of the 'air gap' found in conventional one-gravity systems. Basic design data are presented including pressure drop, scaling factors, sizing criteria, and the results of challenging the device with suspensions of seven microorganisms including aerobes, anaerobes and spore formers.

  9. Microbial processes and subsurface contaminants

    NASA Astrophysics Data System (ADS)

    Molz, Fred J.

    A Chapman Conference entitled “Microbial Processes in the Transport, Fate, and In Situ Treatment of Subsurface Contaminants” was held in Snowbird, Utah, October 1-3, 1986. Members of the program committee and session chairmen were Lenore Clesceri (Rensselaer Polytechnic Institute, Troy, N.Y.), David Gibson (University of Texas, Austin), James Mercer (GeoTrans, Inc., Herndon , Va.), Donald Michelsen (Virginia Polytechnic Institute and State University, Blacksburg), Fred Molz (Auburn University, Auburn, Ala.), Bruce Rittman (University of Illinois, Urbana), Gary Sayler (University of Tennessee, Knoxville), and John T. Wilson (U.S. Environmental Protection Agency, Ada, Okla.). The following report attempts to highlight the six sessions that constituted the conference. For additional information, including a bound summary and abstracts, contact Fred J. Molz, Civil Engineering Department, Auburn University, AL 36849 (telephone: 205-826-4321).

  10. Resolution in forensic microbial genotyping

    SciTech Connect

    Velsko, S P

    2005-08-30

    Resolution is a key parameter for differentiating among the large number of strain typing methods that could be applied to pathogens involved in bioterror events or biocrimes. In this report we develop a first-principles analysis of strain typing resolution using a simple mathematical model to provide a basis for the rational design of microbial typing systems for forensic applications. We derive two figures of merit that describe the resolving power and phylogenetic depth of a strain typing system. Rough estimates of these figures-of-merit for MLVA, MLST, IS element, AFLP, hybridization microarrays, and other bacterial typing methods are derived from mutation rate data reported in the literature. We also discuss the general problem of how to construct a ''universal'' practical typing system that has the highest possible resolution short of whole-genome sequencing, and that is applicable with minimal modification to a wide range of pathogens.

  11. Analysis of Illumina Microbial Assemblies

    SciTech Connect

    Clum, Alicia; Foster, Brian; Froula, Jeff; LaButti, Kurt; Sczyrba, Alex; Lapidus, Alla; Woyke, Tanja

    2010-05-28

    Since the emerging of second generation sequencing technologies, the evaluation of different sequencing approaches and their assembly strategies for different types of genomes has become an important undertaken. Next generation sequencing technologies dramatically increase sequence throughput while decreasing cost, making them an attractive tool for whole genome shotgun sequencing. To compare different approaches for de-novo whole genome assembly, appropriate tools and a solid understanding of both quantity and quality of the underlying sequence data are crucial. Here, we performed an in-depth analysis of short-read Illumina sequence assembly strategies for bacterial and archaeal genomes. Different types of Illumina libraries as well as different trim parameters and assemblers were evaluated. Results of the comparative analysis and sequencing platforms will be presented. The goal of this analysis is to develop a cost-effective approach for the increased throughput of the generation of high quality microbial genomes.

  12. Biofilms: Microbial Life on Surfaces

    PubMed Central

    2002-01-01

    Microorganisms attach to surfaces and develop biofilms. Biofilm-associated cells can be differentiated from their suspended counterparts by generation of an extracellular polymeric substance (EPS) matrix, reduced growth rates, and the up- and down- regulation of specific genes. Attachment is a complex process regulated by diverse characteristics of the growth medium, substratum, and cell surface. An established biofilm structure comprises microbial cells and EPS, has a defined architecture, and provides an optimal environment for the exchange of genetic material between cells. Cells may also communicate via quorum sensing, which may in turn affect biofilm processes such as detachment. Biofilms have great importance for public health because of their role in certain infectious diseases and importance in a variety of device-related infections. A greater understanding of biofilm processes should lead to novel, effective control strategies for biofilm control and a resulting improvement in patient management. PMID:12194761

  13. Microbial deprivation, inflammation and cancer.

    PubMed

    von Hertzen, Leena C; Joensuu, H; Haahtela, T

    2011-06-01

    Dysregulated immune function is involved in the pathogenesis of many common human diseases. Living in urban, microbe-poor environment may have a profound influence on the immune function and eventually also on carcinogenesis. Unfortunately, few studies have thus far addressed the role of exposure to the environmental microbiota on the risk of cancer. Which mechanisms are broken in individuals prone to develop chronic inflammation in response to exposure that does not cause harm in others? Recent work in immunology has revealed that Th17 cells, a third subset of Th cells, and inflammatory cytokines, particularly IL-23, are closely linked with tumour-associated inflammation. Albeit the precise role of Th17 cells in cancer is still unclear and a matter of debate, accumulating evidence shows that Th17 cells are enriched in a wide range of human tumours, and that these tumour-derived Th17 cells may promote angiogenesis, tumour growth and inflammation. Regulatory T cells, in turn, appear to have counter-regulatory effects on Th17 cells and can inhibit their function. Thus, the regulatory network, induced and strengthened by continuous exposure to environmental microbiota, may play an important role in tumour immunobiology in preventing the establishment of chronic inflammation in its early phases. In addition, the discovery of the Toll-like receptor (TLR) system has brought micro-organisms to new light; continuous signalling via these TLRs and other receptors that sense microbial components is necessary for epithelial cell integrity, tissue repair, and recovery from injury. In this communication, we summarise the epidemiological data of living in environments with diverse microbial exposures and the risk of cancer, and discuss the related immunological mechanisms, focusing on the links between environmental microbiota, the Th17/IL-23 axis and cancer-associated inflammation.

  14. Interspecies Interactions within Oral Microbial Communities

    PubMed Central

    Kuramitsu, Howard K.; He, Xuesong; Lux, Renate; Anderson, Maxwell H.; Shi, Wenyuan

    2007-01-01

    Summary: While reductionism has greatly advanced microbiology in the past 400 years, assembly of smaller pieces just could not explain the whole! Modern microbiologists are learning “system thinking” and “holism.” Such an approach is changing our understanding of microbial physiology and our ability to diagnose/treat microbial infections. This review uses oral microbial communities as a focal point to describe this new trend. With the common name “dental plaque,” oral microbial communities are some of the most complex microbial floras in the human body, consisting of more than 700 different bacterial species. For a very long time, oral microbiologists endeavored to use reductionism to identify the key genes or key pathogens responsible for oral microbial pathogenesis. The limitations of reductionism forced scientists to begin adopting new strategies using emerging concepts such as interspecies interaction, microbial community, biofilms, polymicrobial disease, etc. These new research directions indicate that the whole is much more than the simple sum of its parts, since the interactions between different parts resulted in many new physiological functions which cannot be observed with individual components. This review describes some of these interesting interspecies-interaction scenarios. PMID:18063722

  15. Microbial monitoring of spacecraft and associated environments

    NASA Technical Reports Server (NTRS)

    La Duc, M. T.; Kern, R.; Venkateswaran, K.

    2004-01-01

    Rapid microbial monitoring technologies are invaluable in assessing contamination of spacecraft and associated environments. Universal and widespread elements of microbial structure and chemistry are logical targets for assessing microbial burden. Several biomarkers such as ATP, LPS, and DNA (ribosomal or spore-specific), were targeted to quantify either total bioburden or specific types of microbial contamination. The findings of these assays were compared with conventional, culture-dependent methods. This review evaluates the applicability and efficacy of some of these methods in monitoring the microbial burden of spacecraft and associated environments. Samples were collected from the surfaces of spacecraft, from surfaces of assembly facilities, and from drinking water reservoirs aboard the International Space Station (ISS). Culture-dependent techniques found species of Bacillus to be dominant on these surfaces. In contrast, rapid, culture-independent techniques revealed the presence of many Gram-positive and Gram-negative microorganisms, as well as actinomycetes and fungi. These included both cultivable and noncultivable microbes, findings further confirmed by DNA-based microbial detection techniques. Although the ISS drinking water was devoid of cultivable microbes, molecular-based techniques retrieved DNA sequences of numerous opportunistic pathogens. Each of the methods tested in this study has its advantages, and by coupling two or more of these techniques even more reliable information as to microbial burden is rapidly obtained. Copyright 2004 Springer-Verlag.

  16. Microbial stress priming: a meta-analysis.

    PubMed

    Andrade-Linares, Diana R; Lehmann, Anika; Rillig, Matthias C

    2016-04-01

    Microbes have to cope with complex and dynamic environments, making it likely that anticipatory responses provide fitness benefits. Mild, previous stressors can prepare microbes (stress priming) to further and potentially damaging stressors (triggering). We here quantitatively summarize the findings from over 250 trials of 34 studies including bacteria and fungi, demonstrating that priming to stress has a beneficial impact on microbial survival. In fact, survival of primed microbes was about 10-fold higher compared with that in non-primed microbes. Categorical moderators related to microbial taxonomy and the kind of stress applied as priming or as triggering revealed significant differences of priming effect size among 14 different microbial species, 6 stress categories and stressor combination. We found that priming by osmotic, physiological and temperature stress had the highest positive effect sizes on microbial response. Cross-protection was evident for physiological, temperature and pH stresses. Microbes are better prepared against triggering by oxidative, temperature and osmotic stress. Our finding of an overall positive mean effect of priming regardless of the microbial system and particular stressor provides unprecedentedly strong evidence of the broad ecological significance of microbial stress priming. These results further suggest that stress priming may be an important factor in shaping microbial communities.

  17. Microbial monitoring of spacecraft and associated environments.

    PubMed

    La Duc, M T; Kern, R; Venkateswaran, K

    2004-02-01

    Rapid microbial monitoring technologies are invaluable in assessing contamination of spacecraft and associated environments. Universal and widespread elements of microbial structure and chemistry are logical targets for assessing microbial burden. Several biomarkers such as ATP, LPS, and DNA (ribosomal or spore-specific), were targeted to quantify either total bioburden or specific types of microbial contamination. The findings of these assays were compared with conventional, culture-dependent methods. This review evaluates the applicability and efficacy of some of these methods in monitoring the microbial burden of spacecraft and associated environments. Samples were collected from the surfaces of spacecraft, from surfaces of assembly facilities, and from drinking water reservoirs aboard the International Space Station (ISS). Culture-dependent techniques found species of Bacillus to be dominant on these surfaces. In contrast, rapid, culture-independent techniques revealed the presence of many Gram-positive and Gram-negative microorganisms, as well as actinomycetes and fungi. These included both cultivable and noncultivable microbes, findings further confirmed by DNA-based microbial detection techniques. Although the ISS drinking water was devoid of cultivable microbes, molecular-based techniques retrieved DNA sequences of numerous opportunistic pathogens. Each of the methods tested in this study has its advantages, and by coupling two or more of these techniques even more reliable information as to microbial burden is rapidly obtained.

  18. Historical Contingencies in Microbial Responses to Drought

    NASA Astrophysics Data System (ADS)

    Hawkes, C.; Waring, B.; Rocca, J.; Kivlin, S.; Giauque, H.; Averill, C.

    2014-12-01

    Although water is a primary controller of microbial function and we expect climate change to alter water availability in the future, our understanding of how microbial communities respond to a change in moisture and what that means for soil carbon cycling remain poorly understood. In part, this uncertainty arises from a lack of understanding of microbial response mechanisms and how those lead to aggregate soil function. Environmental tracking would be facilitated if microbial communities respond to new climatic conditions via rapid physiological acclimatization, shifts in community composition, or adaptation. In contrast, historical contingencies could be created by dispersal limitation or local adaptation to previous conditions. To address environmental tracking vs. legacies, we examined how soil microbial communities were affected by precipitation at multiple scales and asked whether rainfall was a primary driver of the observed responses. We leveraged a local steep rainfall gradient with field surveys, lab incubations, reciprocal transplants, and rainfall manipulations to approach this problem. Across a steep rainfall gradient, we found that soil microbial communities were strongly associated with historical rainfall, with two-thirds of the variation in community composition explained by mean annual precipitation. In 12-month experimental lab manipulations of soil moisture, soil functional responses were constrained by historical rainfall, with greater activity in soils subjected to their original moisture condition. The constraints of historical rainfall held even after 18 months in reciprocal transplant common gardens along the rainfall gradient and with manipulated dispersal of regional microbial communities. Yet, when water was manipulated at a single site over 4 years, legacies did not develop. Overall, these findings are consistent with long-term rainfall acting as a strong habitat filter and resulting in a legacy of both microbial community composition

  19. Biotechnological Processes in Microbial Amylase Production

    PubMed Central

    Arshad, M. K. Md; Lakshmipriya, Thangavel; Hashim, Uda; Chinni, Suresh V.

    2017-01-01

    Amylase is an important and indispensable enzyme that plays a pivotal role in the field of biotechnology. It is produced mainly from microbial sources and is used in many industries. Industrial sectors with top-down and bottom-up approaches are currently focusing on improving microbial amylase production levels by implementing bioengineering technologies. The further support of energy consumption studies, such as those on thermodynamics, pinch technology, and environment-friendly technologies, has hastened the large-scale production of the enzyme. Herein, the importance of microbial (bacteria and fungi) amylase is discussed along with its production methods from the laboratory to industrial scales. PMID:28280725

  20. Improved microbial-check-valve resins

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.; Putnam, D. F.

    1980-01-01

    Improved microbial-check-valve resins have been tested for their microbicidal effectiveness and long-term stability. Resins give more-stable iodine concentrations than previous preparations and do not impart objectionable odor or taste to treated water. Microbial check valve is small cylindrical device, packed with iodide-saturated resin, that is installed in water line where contamination by micro-organisms is to be prevented. Prototype microbial check valve was tested for stability and performance under harsh environmental conditions. Effectiveness was 100 percent at 35 deg, 70 deg, and 160 deg F (2 deg, 21 deg, and 71 deg C).

  1. Pollutant effects on the microbial ecosystem.

    PubMed Central

    Ford, T

    1994-01-01

    Genetic diversity of a microbial community will inevitably be affected by environmental stress. However, our understanding of the implications of these effects is limited. Genetic exchange between natural microbial communities appears to be a common phenomenon, mediated by a number of microbial processes (conjugation, transformation, and transduction). These mechanisms of change are presumably adaptations to natural environmental perturbation, e.g., the low levels of antibiotics produced by other organisms. However, anthropogenic influences on the environment may be accelerating genetic change within microbiologic ecosystems, beyond these natural adaptation rates. This article highlights some of the perceived risks to ecosystem health and research questions that need to be addressed. PMID:7713033

  2. EVA Suit Microbial Leakage Investigation Project

    NASA Technical Reports Server (NTRS)

    Falker, Jay; Baker, Christopher; Clayton, Ronald; Rucker, Michelle

    2016-01-01

    The objective of this project is to collect microbial samples from various EVA suits to determine how much microbial contamination is typically released during simulated planetary exploration activities. Data will be released to the planetary protection and science communities, and advanced EVA system designers. In the best case scenario, we will discover that very little microbial contamination leaks from our current or prototype suit designs, in the worst case scenario, we will identify leak paths, learn more about what affects leakage--and we'll have a new, flight-certified swab tool for our EVA toolbox.

  3. Tackling the climate targets set by the Paris Agreement (COP 21): Green leadership empowers public hospitals to overcome obstacles and challenges in a resource-constrained environment.

    PubMed

    Weimann, E; Patel, B

    2016-12-21

    The healthcare sector itself contributes to climate change, the creation of hazardous waste, use of toxic metals such as mercury, and water and air pollution. To mitigate the effect of healthcare provision on the deteriorating environment and avoid creating further challenges for already burdened health systems, Global Green Hospitals was formed as a global network. Groote Schuur Hospital (GSH), as the leading academic hospital in Africa, joined the network in 2014. Since then, several projects have been initiated to reduce the amount of general waste, energy consumption and food waste, and create an environmentally friendlier and more sustainable hospital in a resource-constrained public healthcare setting. We outline the various efforts made to reduce the carbon footprint of GSH and reduce waste and hazardous substances such as mercury and polystyrene, and elaborate how obstacles and resistance to change were overcome. The hospital was able to halve the amount of coal and water used, increase recycling by 50% over 6 months, replace polystyrene cups and packaging with Forest Stewardship Council recyclable paper-based products, reduce the effect of food wastage by making use of local farmers, and implement measures to reduce the amount of expired pharmaceutical drugs. To improve commitment from all involved roleplayers, political leadership, supportive government policies and financial funding is mandatory, or public hospitals will be unable to tackle the exponentially increasing costs related to climate change and its effects on healthcare.

  4. The politics of partnerships: a study of police and housing collaboration to tackle anti-social behaviour on Australian public housing estates.

    PubMed

    Jacobs, Keith

    2010-01-01

    This paper draws on the findings from a research project on partnership arrangements between the police and housing departments on three Australian public housing estates to tackle problems associated with illicit drug activity and anti-social behaviour (ASB). The analysis focused on the setting up of the partnerships and the interactions that followed from these institutional arrangements. The assumption that informs the paper is that when studying partnerships there is a need for a more critically framed analysis. The temptation to posit "a successful model" of what partnership entails and then to judge practices in relation to this model is considerable, but it inevitably falls into the trap of constructing a narrative of partnership success or failure in terms of individual agency (that is, the degree of commitment from individuals). The analysis undertaken in this paper has therefore sought to fathom a more complex set of organizational processes. Rather than confine the discussion to issues of success and failure, the study foregrounds the subjective accounts of individuals who work within partnership and the constraints they encounter. The paper therefore makes explicit the cultural tensions within and across agencies, contestation as to the extent of the policy "problem," and the divergent perspectives on the appropriate modes of intervention.

  5. Combining microbial cultures for efficient production of electricity from butyrate in a microbial electrochemical cell.

    PubMed

    Miceli, Joseph F; Garcia-Peña, Ines; Parameswaran, Prathap; Torres, César I; Krajmalnik-Brown, Rosa

    2014-10-01

    Butyrate is an important product of anaerobic fermentation; however, it is not directly used by characterized strains of the highly efficient anode respiring bacteria (ARB) Geobacter sulfurreducens in microbial electrochemical cells. By combining a butyrate-oxidizing community with a Geobacter rich culture, we generated a microbial community which outperformed many naturally derived communities found in the literature for current production from butyrate and rivaled the highest performing natural cultures in terms of current density (∼ 11A/m(2)) and Coulombic efficiency (∼ 70%). Microbial community analyses support the shift in the microbial community from one lacking efficient ARB in the marine hydrothermal vent community to a community consisting of ∼ 80% Geobacter in the anode biofilm. This demonstrates the successful production and adaptation of a novel microbial culture for generating electrical current from butyrate with high current density and high Coulombic efficiency, by combining two mixed microbial cultures containing complementing biochemical pathways.

  6. Modern Microbial Fossilization Processes as Signatures for Interpreting Ancient Terrestrial and Extraterrestrial Microbial Forms

    NASA Technical Reports Server (NTRS)

    Morris, Penny A.; Wentworth, Susan J.; Nelman, Mayra; Byrne, Monica; Longazo, Teresa; Galindo, Charles; McKay, David S.; Sams, Clarence

    2003-01-01

    Terrestrial biotas from microbially dominated hypersaline environments will help us understand microbial fossilization processes. Hypersaline tolerant biota from Storr's Lake, San Salvador Island (Bahamas), Mono Lake (California), and the Dead Sea (Israel) represent marine and nonmarine sites for comparative studies of potential analogs for interpreting some Mars meteorites and Mars sample return rocks [1,2,3,4,5,6]. The purpose of this study is to compare microbial fossilization processes, the dominant associated minerals, and potential diagenic implications.

  7. 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

  8. Microbial fuel cells and microbial ecology: applications in ruminant health and production research.

    PubMed

    Bretschger, Orianna; Osterstock, Jason B; Pinchak, William E; Ishii, Shun'ichi; Nelson, Karen E

    2010-04-01

    Microbial fuel cell (MFC) systems employ the catalytic activity of microbes to produce electricity from the oxidation of organic, and in some cases inorganic, substrates. MFC systems have been primarily explored for their use in bioremediation and bioenergy applications; however, these systems also offer a unique strategy for the cultivation of synergistic microbial communities. It has been hypothesized that the mechanism(s) of microbial electron transfer that enable electricity production in MFCs may be a cooperative strategy within mixed microbial consortia that is associated with, or is an alternative to, interspecies hydrogen (H(2)) transfer. Microbial fermentation processes and methanogenesis in ruminant animals are highly dependent on the consumption and production of H(2)in the rumen. Given the crucial role that H(2) plays in ruminant digestion, it is desirable to understand the microbial relationships that control H(2) partial pressures within the rumen; MFCs may serve as unique tools for studying this complex ecological system. Further, MFC systems offer a novel approach to studying biofilms that form under different redox conditions and may be applied to achieve a greater understanding of how microbial biofilms impact animal health. Here, we present a brief summary of the efforts made towards understanding rumen microbial ecology, microbial biofilms related to animal health, and how MFCs may be further applied in ruminant research.

  9. Microbial Fuel Cells and Microbial Ecology: Applications in Ruminant Health and Production Research

    PubMed Central

    Osterstock, Jason B.; Pinchak, William E.; Ishii, Shun’ichi; Nelson, Karen E.

    2009-01-01

    Microbial fuel cell (MFC) systems employ the catalytic activity of microbes to produce electricity from the oxidation of organic, and in some cases inorganic, substrates. MFC systems have been primarily explored for their use in bioremediation and bioenergy applications; however, these systems also offer a unique strategy for the cultivation of synergistic microbial communities. It has been hypothesized that the mechanism(s) of microbial electron transfer that enable electricity production in MFCs may be a cooperative strategy within mixed microbial consortia that is associated with, or is an alternative to, interspecies hydrogen (H2) transfer. Microbial fermentation processes and methanogenesis in ruminant animals are highly dependent on the consumption and production of H2in the rumen. Given the crucial role that H2 plays in ruminant digestion, it is desirable to understand the microbial relationships that control H2 partial pressures within the rumen; MFCs may serve as unique tools for studying this complex ecological system. Further, MFC systems offer a novel approach to studying biofilms that form under different redox conditions and may be applied to achieve a greater understanding of how microbial biofilms impact animal health. Here, we present a brief summary of the efforts made towards understanding rumen microbial ecology, microbial biofilms related to animal health, and how MFCs may be further applied in ruminant research. PMID:20024685

  10. Paleobiological Perspectives on Early Microbial Evolution.

    PubMed

    Knoll, Andrew H

    2015-07-01

    Microfossils, stromatolites, and chemical biosignatures indicate that Earth became a biological planet more than 3.5 billion years ago, making most of life's history microbial. Proterozoic rocks preserve a rich record of cyanobacteria, including derived forms that differentiate multiple cell types. Stromatolites, in turn, show that microbial communities covered the seafloor from tidal flats to the base of the photic zone. The Archean record is more challenging to interpret, particularly on the question of cyanobacterial antiquity, which remains to be resolved. In the late Neoproterozoic Era, increasing oxygen and radiating eukaryotes altered the biosphere, with planktonic algae gaining ecological prominence in the water column, whereas seaweeds and, eventually, animals spread across shallow seafloors. From a microbial perspective, however, animals, algae, and, later, plants simply provided new opportunities for diversification, and, to this day, microbial metabolisms remain the only essential components of biogeochemical cycles.

  11. The structure of microbial evolutionary theory.

    PubMed

    Sapp, J

    2007-12-01

    The study of microbial phylogeny and evolution has emerged as an interdisciplinary synthesis, divergent in both methods and concepts from the classical evolutionary biology. The deployment of macromolecular sequencing in microbial classification has provided a deep evolutionary taxonomy hitherto deemed impossible. Microbial phylogenetics has greatly transformed the landscape of evolutionary biology, not only in revitalizing the field in the pursuit of life's history over billions of years, but also in transcending the structure of thought that has shaped evolutionary theory since the time of Darwin. A trio of primary phylogenetic lineages, along with the recognition of symbiosis and lateral gene transfer as fundamental processes of evolutionary innovation, are core principles of microbial evolutionary biology today. Their scope and significance remain contentious among evolutionists.

  12. Microfluidics expanding the frontiers of microbial ecology.

    PubMed

    Rusconi, Roberto; Garren, Melissa; Stocker, Roman

    2014-01-01

    Microfluidics has significantly contributed to the expansion of the frontiers of microbial ecology over the past decade by allowing researchers to observe the behaviors of microbes in highly controlled microenvironments, across scales from a single cell to mixed communities. Spatially and temporally varying distributions of organisms and chemical cues that mimic natural microbial habitats can now be established by exploiting physics at the micrometer scale and by incorporating structures with specific geometries and materials. In this article, we review applications of microfluidics that have resulted in insightful discoveries on fundamental aspects of microbial life, ranging from growth and sensing to cell-cell interactions and population dynamics. We anticipate that this flexible multidisciplinary technology will continue to facilitate discoveries regarding the ecology of microorganisms and help uncover strategies to control microbial processes such as biofilm formation and antibiotic resistance.

  13. Glycoside Hydrolases across Environmental Microbial Communities

    PubMed Central

    Berlemont, Renaud

    2016-01-01

    Across many environments microbial glycoside hydrolases support the enzymatic processing of carbohydrates, a critical function in many ecosystems. Little is known about how the microbial composition of a community and the potential for carbohydrate processing relate to each other. Here, using 1,934 metagenomic datasets, we linked changes in community composition to variation of potential for carbohydrate processing across environments. We were able to show that each ecosystem-type displays a specific potential for carbohydrate utilization. Most of this potential was associated with just 77 bacterial genera. The GH content in bacterial genera is best described by their taxonomic affiliation. Across metagenomes, fluctuations of the microbial community structure and GH potential for carbohydrate utilization were correlated. Our analysis reveals that both deterministic and stochastic processes contribute to the assembly of complex microbial communities. PMID:27992426

  14. Microbe Wars: A Demonstration of Microbial Antagonism.

    ERIC Educational Resources Information Center

    Fox, Marty

    1997-01-01

    Describes an exercise ideal for use in an introductory biology or microbiology course. Requires no special equipment, little expertise in microbiology, and provides a colorful demonstration of microbial interaction. (DDR)

  15. MICROBIAL BIOFILMS AS INDICATORS OF ESTUARINE CONDITION

    EPA Science Inventory

    Microbial biofilms are complex communities of bacteria, protozoa, microalgae, and micrometazoa which exist in a polymer matrix on submerged surfaces. Their development is integrative of environmental conditions and is affected by local biodiversity, the availability of organic ma...

  16. Procedures For Microbial-Ecology Laboratory

    NASA Technical Reports Server (NTRS)

    Huff, Timothy L.

    1993-01-01

    Microbial Ecology Laboratory Procedures Manual provides concise and well-defined instructions on routine technical procedures to be followed in microbiological laboratory to ensure safety, analytical control, and validity of results.

  17. Surface reflectance degradation by microbial communities

    DOE PAGES

    Cheng, Meng -Dawn; Allman, Steve L.; Graham, David E.; ...

    2015-11-05

    Building envelope, such as a roof, is the interface between a building structure and the environment. Understanding of the physics of microbial interactions with the building envelope is limited. In addition to the natural weathering, microorganisms and airborne particulate matter that attach to a cool roof tend to reduce the roof reflectance over time, compromising the energy efficiency advantages of the reflective coating designs. We applied microbial ecology analysis to identify the natural communities present on the exposed coatings and investigated the reduction kinetics of the surface reflectance upon the introduction of a defined mixture of both photoautotrophic and heterotrophicmore » microorganisms representing the natural communities. The result are (1) reflectance degradation by microbial communities follows a first-order kinetic relationship and (2) more than 50% of degradation from the initial reflectance value can be caused by microbial species alone in much less time than 3 years required by the current standard ENERGY STAR® test methods.« less

  18. 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.

  19. Support for marine microbial ecology research

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-04-01

    Support for marine microbial ecology research A new research competition will provide support to innovative scientists in marine microbial ecology and related fields, the Gordon and Betty Moore Foundation announced on 30 March. The foundation's Investigators in Marine Microbiology program will select 10-15 current and emerging leaders based on their potential to conduct cutting-edge research on the principles that govern microbially mediated nutrient flow and the interactions among marine microbes in ocean ecosystems. The foundation will invest a total of $25 million in the new investigator program over the next 5 years. The competition is open to researchers around the world at varying stages of their careers who represent a variety of scientific backgrounds, including microbial ecology, biogeochemistry, evolutionary biology, and bioinformatics.

  20. A thermodynamic theory of microbial growth

    PubMed Central

    Desmond-Le Quéméner, Elie; Bouchez, Théodore

    2014-01-01

    Our ability to model the growth of microbes only relies on empirical laws, fundamentally restricting our understanding and predictive capacity in many environmental systems. In particular, the link between energy balances and growth dynamics is still not understood. Here we demonstrate a microbial growth equation relying on an explicit theoretical ground sustained by Boltzmann statistics, thus establishing a relationship between microbial growth rate and available energy. The validity of our equation was then questioned by analyzing the microbial isotopic fractionation phenomenon, which can be viewed as a kinetic consequence of the differences in energy contents of isotopic isomers used for growth. We illustrate how the associated theoretical predictions are actually consistent with recent experimental evidences. Our work links microbial population dynamics to the thermodynamic driving forces of the ecosystem, which opens the door to many biotechnological and ecological developments. PMID:24522260

  1. Microbial fructosyltransferases and the role of fructans.

    PubMed

    Velázquez-Hernández, M L; Baizabal-Aguirre, V M; Bravo-Patiño, A; Cajero-Juárez, M; Chávez-Moctezuma, M P; Valdez-Alarcón, J J

    2009-06-01

    Microbial fructosyltransferases are polymerases that are involved in microbial fructan (levan, inulin and fructo-oligosaccharide) biosynthesis. Structurally, microbial fructosyltransferase proteins share the catalytic domain of glycoside hydrolases 68 family and are grouped in seven phylogenetically related clusters. Fructosyltransferase-encoding genes are organized in operons or in clusters associated with other genes related to carbohydrate metabolism or fructosyltransferase secretion. Fructosyltransferase gene expression is mainly regulated by two-component systems or phosphorelay mechanisms that respond to sucrose availability or other environmental signals. Microbial fructans are involved in conferring resistance to environmental stress such as water deprivation, nutrient assimilation, biofilm formation, and as virulence factors in colonization. As a result of the biological and industrial importance of fructans, fructosyltransferases have been the subject of extensive research, conducted to improve their enzymatic activity or to elucidate their biological role in nature.

  2. Microbial contributions to the Precambrian Earth

    NASA Technical Reports Server (NTRS)

    Margulis, L.; Bermudes, D.; Obar, R.

    1986-01-01

    Life has existed on Earth for approximately 3.5 billion years. For most of this time, prokaryotic communities provided the major biological forces changing the Earth. Many changes in atmospheric gas composition occurred during the Archean and Proterozoic eons as a result of microbial activity. Extant microbial communities were used to help understand the dynamics which contributed to these atmospheric changes. The microbial mat communities were characterized according to the organismic constituents. Symbiosis in microbial communities is recognized as a major force in cell evolution. Among the evolutinary enigmas investigated is the problem of the origin of the undulipodia. Undulipodial microtubules are still deployed for major cellular processes such as mitosis and meiosis. Several prokaryotes were tested for the presence of the S1-type protein, so far only spirochetes were found to possess it. The S1-type protein is being sought in cyanobacteria reported to contain microtubules.

  3. 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...

  4. Novel trends for use of microbial tannases.

    PubMed

    Zhang, Shuai; Gao, Xiangyang; He, Liping; Qiu, Yuanxin; Zhu, Huawei; Cao, Yong

    2015-01-01

    Tannases, mainly produced by microorganisms, are able to hydrolyze gallotannins, ellagitannins, complex tannins, and gallic acid esters into gallic acid, ellagic acid, glucose, or alcohols, and also synthesize gallic acid esters using tannic acid or gallic acid with a variety of alcohols in nonaqueous media. Microbial tannases have been widely applied especially in beverage processing, pharmaceutics, and brewing. However, many factors, especially high production costs, severely limit the use of microbial tannases at the industrial level. In this minireview, we aim to provide an overview of the advances in applications of microbial tannases during the last 15 years, mainly including the following respects: hydrolysis of tea cream, modification of green tea catechins, production of gallic acid, debittering of fruit juices, degradation of tannery effluents, and synthesis of propyl gallate, trying to know the trends and prospects for the future in applications of microbial tannases.

  5. A thermodynamic theory of microbial growth.

    PubMed

    Desmond-Le Quéméner, Elie; Bouchez, Théodore

    2014-08-01

    Our ability to model the growth of microbes only relies on empirical laws, fundamentally restricting our understanding and predictive capacity in many environmental systems. In particular, the link between energy balances and growth dynamics is still not understood. Here we demonstrate a microbial growth equation relying on an explicit theoretical ground sustained by Boltzmann statistics, thus establishing a relationship between microbial growth rate and available energy. The validity of our equation was then questioned by analyzing the microbial isotopic fractionation phenomenon, which can be viewed as a kinetic consequence of the differences in energy contents of isotopic isomers used for growth. We illustrate how the associated theoretical predictions are actually consistent with recent experimental evidences. Our work links microbial population dynamics to the thermodynamic driving forces of the ecosystem, which opens the door to many biotechnological and ecological developments.

  6. Surface reflectance degradation by microbial communities

    SciTech Connect

    Cheng, Meng -Dawn; Allman, Steve L.; Graham, David E.; Cheng, Karen R.; Pfiffner, Susan Marie; Vishnivetskaya, Tatiana A.; Desjarlais, Andre Omer

    2015-11-05

    Building envelope, such as a roof, is the interface between a building structure and the environment. Understanding of the physics of microbial interactions with the building envelope is limited. In addition to the natural weathering, microorganisms and airborne particulate matter that attach to a cool roof tend to reduce the roof reflectance over time, compromising the energy efficiency advantages of the reflective coating designs. We applied microbial ecology analysis to identify the natural communities present on the exposed coatings and investigated the reduction kinetics of the surface reflectance upon the introduction of a defined mixture of both photoautotrophic and heterotrophic microorganisms representing the natural communities. The result are (1) reflectance degradation by microbial communities follows a first-order kinetic relationship and (2) more than 50% of degradation from the initial reflectance value can be caused by microbial species alone in much less time than 3 years required by the current standard ENERGY STAR® test methods.

  7. Microfabricated devices in microbial bioenergy sciences.

    PubMed

    Han, Arum; Hou, Huijie; Li, Lei; Kim, Hyun Soo; de Figueiredo, Paul

    2013-04-01

    Microbes provide a platform for the synthesis of clean energy from renewable resources. Significant investments in discovering new microbial systems and capabilities, discerning the molecular mechanisms that mediate microbial bioenergy production, and optimizing existing microbial bioenergy systems have been made. However, further development is needed to achieve the economically feasible large-scale production of value-added energy products. Microfabricated lab-on-a-chip systems provide cost- and time-efficient opportunities for analyzing microbe-mediated bioenergy synthesis. Here, we review developments in the application of lab-on-a-chip systems to the bioenergy sciences. We focus on systems that support the analysis of microbial generation of bioelectricity, biogas, and liquid transportation fuels. We conclude by suggesting possible future directions.

  8. Microbial diversity arising from thermodynamic constraints

    PubMed Central

    Großkopf, Tobias; Soyer, Orkun S

    2016-01-01

    The microbial world displays an immense taxonomic diversity. This diversity is manifested also in a multitude of metabolic pathways that can utilise different substrates and produce different products. Here, we propose that these observations directly link to thermodynamic constraints that inherently arise from the metabolic basis of microbial growth. We show that thermodynamic constraints can enable coexistence of microbes that utilise the same substrate but produce different end products. We find that this thermodynamics-driven emergence of diversity is most relevant for metabolic conversions with low free energy as seen for example under anaerobic conditions, where population dynamics is governed by thermodynamic effects rather than kinetic factors such as substrate uptake rates. These findings provide a general understanding of the microbial diversity based on the first principles of thermodynamics. As such they provide a thermodynamics-based framework for explaining the observed microbial diversity in different natural and synthetic environments. PMID:27035705

  9. Microbial biotransformation of bioactive flavonoids.

    PubMed

    Cao, Hui; Chen, Xiaoqing; Jassbi, Amir Reza; Xiao, Jianbo

    2015-01-01

    The bioactive flavonoids are considered as the most important phytochemicals in food, which exert a wide range of biological benefits for human being. Microbial biotransformation strategies for production of flavonoids have attracted considerable interest because they allow yielding novel flavonoids, which do not exist in nature. In this review, we summarize the existing knowledge on the production and biotransformation of flavonoids by various microbes. The main reactions during microbial biotransformation are hydroxylation, dehydroxylation, O-methylation, O-demethylation, glycosylation, deglycosylation, dehydrogenation, hydrogenation, C ring cleavage of the benzo-γ-pyrone system, cyclization, and carbonyl reduction. Cunninghamella, Penicillium, and Aspergillus strains are very popular to biotransform flavonoids and they can perform almost all the reactions with excellent yields. Aspergillus niger is one of the most applied microorganisms in the flavonoids' biotransformation; for example, A. niger can transfer flavanone to flavan-4-ol, 2'-hydroxydihydrochalcone, flavone, 3-hydroxyflavone, 6-hydroxyflavanone, and 4'-hydroxyflavanone. The hydroxylation of flavones by microbes usually happens on the ortho position of hydroxyl group on the A ring and C-4' position of the B ring and microbes commonly hydroxylate flavonols at the C-8 position. The microorganisms tend to hydroxylate flavanones at the C-5, 6, and 4' positions; however, for prenylated flavanones, dihydroxylation often takes place on the C4α=C5α double bond on the prenyl group (the side chain of A ring). Isoflavones are usually hydroxylated at the C-3' position of the B ring by microorganisms. The microbes convert flavonoids to their 7-O-glycosides and 3-O-glycosides (when flavonoids have a hydroxyl moiety at the C-3 position). The demethylation of multimethoxyl flavonoids by microbes tends to happen at the C-3' and C-4' positions of the B ring. Multimethoxyl flavanones and isoflavone are demethylated at

  10. 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

  11. Microbial identification by mass cataloging

    PubMed Central

    Zhang, Zhengdong; Jackson, George W; Fox, George E; Willson, Richard C

    2006-01-01

    Background The public availability of over 180,000 bacterial 16S ribosomal RNA (rRNA) sequences has facilitated microbial identification and classification using hybridization and other molecular approaches. In their usual format, such assays are based on the presence of unique subsequences in the target RNA and require a prior knowledge of what organisms are likely to be in a sample. They are thus limited in generality when analyzing an unknown sample. Herein, we demonstrate the utility of catalogs of masses to characterize the bacterial 16S rRNA(s) in any sample. Sample nucleic acids are digested with a nuclease of known specificity and the products characterized using mass spectrometry. The resulting catalogs of masses can subsequently be compared to the masses known to occur in previously-sequenced 16S rRNAs allowing organism identification. Alternatively, if the organism is not in the existing database, it will still be possible to determine its genetic affinity relative to the known organisms. Results Ribonuclease T1 and ribonuclease A digestion patterns were calculated for 1,921 complete 16S rRNAs. Oligoribonucleotides generated by RNase T1 of length 9 and longer produce sufficient diversity of masses to be informative. In addition, individual fragments or combinations thereof can be used to recognize the presence of specific organisms in a complex sample. In this regard, 140 strains out of 1,921 organisms (7.3%) could be identified by the presence of a unique RNase T1-generated oligoribonucleotide mass. Combinations of just two and three oligoribonucleotide masses allowed 54% and 72% of the specific strains to be identified, respectively. An initial algorithm for recovering likely organisms present in complex samples is also described. Conclusion The use of catalogs of compositions (masses) of characteristic oligoribonucleotides for microbial identification appears extremely promising. RNase T1 is more useful than ribonuclease A in generating characteristic

  12. Tackling important issues in Europe.

    PubMed

    de Lange, Karin

    2014-06-14

    Forthcoming animal health legislation, antimicrobial resistance and corporate practice were all discussed at the recent general assembly of the Federation of Veterinarians of Europe. Karin de Lange reports.

  13. Transformative tools for tackling tuberculosis.

    PubMed

    Gardiner, Jennifer L; Karp, Christopher L

    2015-10-19

    The world is in need of more effective approaches to controlling tuberculosis. The development of improved control strategies has been hampered by deficiencies in the tools available for detecting Mycobacterium tuberculosis and defining the dynamic consequences of the interaction of M. tuberculosis with its human host. Key needs include a highly sensitive, specific nonsputum diagnostic; biomarkers predictive of responses to therapy; correlates of risk for disease development; and host response-independent markers of M. tuberculosis infection. Tools able to sensitively detect and quantify total body M. tuberculosis burden might well be transformative across many needed use cases. Here, we review the current state of the field, paying particular attention to needed changes in experimental paradigms that would facilitate the discovery, validation, and development of such tools.

  14. Tackling Teens' No. 1 Problem.

    ERIC Educational Resources Information Center

    Adair, Jan

    2000-01-01

    Drug Strategies' updated guide evaluates the 50 most popular U.S. prevention programs. Project ALERT scored high in overall quality, administrative ease, and rehearsal and role plays. Key components include age appropriateness, identification of social pressures, instruction in refusal skills, interactivity, normative education, family…

  15. Virgin's Knight tackles climate change

    NASA Astrophysics Data System (ADS)

    Banks, Michael

    2008-11-01

    "There is no greater or more immediate challenge than that posed by climate change," said Sir Richard Branson, chairman of the Virgin group, via video-link at the 59th International Astronautical Congress (IAC) held in Glasgow in the UK at the end of September. That grand statement may seem like a lot of hot air for the entrepreneur best known for his attempt to circumnavigate the globe by balloon. But Branson went on to reveal that Virgin Galactic, which aims to fly passengers 100 km into space for 200 000 per trip, will also provide room on its craft for a series of scientific experiments to study the Earth's atmosphere.

  16. Transformative tools for tackling tuberculosis

    PubMed Central

    2015-01-01

    The world is in need of more effective approaches to controlling tuberculosis. The development of improved control strategies has been hampered by deficiencies in the tools available for detecting Mycobacterium tuberculosis and defining the dynamic consequences of the interaction of M. tuberculosis with its human host. Key needs include a highly sensitive, specific nonsputum diagnostic; biomarkers predictive of responses to therapy; correlates of risk for disease development; and host response–independent markers of M. tuberculosis infection. Tools able to sensitively detect and quantify total body M. tuberculosis burden might well be transformative across many needed use cases. Here, we review the current state of the field, paying particular attention to needed changes in experimental paradigms that would facilitate the discovery, validation, and development of such tools. PMID:26458772

  17. Tackling Malawi's human resources crisis.

    PubMed

    Palmer, Debbie

    2006-05-01

    In sub-Saharan Africa, health systems are fragile and staffing is grossly inadequate to meet rising health needs. Despite growing international attention, donors have been reluctant to undertake the significant investments required to address the human resources problem comprehensively, given social and political sensitivities, and concerns regarding sustainability of interventions and risks of rising donor dependency. In Malawi, one of the poorest nations in Africa, declining human resource levels have fueled an accelerating collapse of public health services since the late 1990s. In an effort to improve health outcomes, in 2004 the government launched a new health initiative to deliver an Essential Health Package, including a major scale-up of HIV and AIDS related services. Improving staffing levels is the single biggest challenge to implementing this approach. Donors agreed to help the government develop an Emergency Human Resources Programme with five main facets: improving incentives for recruitment and retention of staff through salary top-ups, expanding domestic training capacity, using international volunteer doctors and nurse tutors as a stop-gap measure, providing international technical assistance to bolster planning and management capacity and skills, and establishing more robust monitoring and evaluation capacity. Industrial relations were a prominent consideration in determining the shape of the Programme. The combination of short- and long-term measures appears to be helpful in maintaining commitment to the programme.

  18. We must tackle population problems.

    PubMed

    Hironaka, W

    1992-03-01

    Thank you Mr. Chairman, for the opportunity to speak out not only as a Japanese parliamentarian, but also as a member of GLOBE International, Global Legislators Organization for a Balanced Environment, consisting of legislators from the US Congress, EC Parliament, USSR Assembly and Japanese Diet who have joined together to compare, improve and coordinate our respective legislative activities in an effort to effectively address the complex issues surrounding environment and development. Mr. Chairman, world population--which reached 5.4 billion in mid-1991--is growing exponentially. According to 1 UNFPA report 3 people are born every second, a total of 250,000 people every day or 95-100 million people every year. At this rate, world population will reach 6.4 billion by year 2001, and if this rate continues to go unchecked, world population will reach 14-15 billion by the end of the 21st century. GLOBE is highly aware of the relationship between rapidly growing human populations, environmental degradation and sustainable development. We urge UNCED negotiators to address population growth rates and the integrally linked concerns of resource consumption levels, particularly in the industrialized world, in their search for solutions to the conflict between environment and development. Negotiators should also seriously consider ways in which to broaden educational and economic opportunities for women to ease population growth rates, and to alleviate poverty and stresses on the environment that result from population pressures. Social and economic factors must be integrated into population planning. It is saddening to note that almost 40,000 children die every day due to malnutrition, lack of fresh water and access to resources. Over 100 million children do not receive a primary education. Mr. Chairman, worldwide demand for a range of family planning services is increasing faster than supply. Recent studies indicate that if quality family planning information, training and services were made readily available by government and other groups, population rates would drop to manageable levels. Widespread access to family planning services is essential to population stabilization. The health of mothers, children and general quality of life is also improved through the implementation of family planning programs. At the present time many women cannot make use of the limited available services because of cultural constraints, lack of status and self-confidence. Unless complementary efforts are made to expand economic and educational opportunities for women, family planning and other reproductive health services will not reach their full potential for stabilizing population. Although family planning is an individual decision, and implementation of population programs is a sovereign matter in each country, I would urge developed countries to help their neighbors in developing countries who are in need of support for family planning and health services. Investment in family planning programs is 1 of the best ways to contribute to environmental protection and improvement. A greater portion of our foreign aid monies should be allocated for direct population assistance programs that will reach people at the grassroots level. To achieve this, a cooperative working relationship with local nongovernmental organization (NGOs) is essential. The members of GLOBE hope to facilitate cooperation between NGOs and governments so that we might stabilize human population.

  19. Tackling Misconceptions about Linear Associations

    ERIC Educational Resources Information Center

    Huey, Maryann E.; Baker, Deidra L.

    2015-01-01

    Many teachers of required secondary school mathematics classes are introducing statistics and probability topics traditionally relegated to college or AP Statistics courses. As a result, they need guidance in preparing lesson plans and orchestrating effective classroom discussions. In this article, the authors will describe the students' learning…

  20. Tackling ageism in cancer treatment.

    PubMed

    Duffin, Christian

    2013-02-01

    Evidence shows that older patients are discriminated against when it comes to cancer treatment. A pilot project was commissioned by the Department of Health in partnership with Macmillan Cancer Support and Age UK. The project involved staff, including nurses, from five cancer networks in England examining ways to improve care for this patient group. Drawing on approaches used in geriatric medicine, patients' needs in accessing treatment were explored by conducting assessments and, for example, providing taxis for hospital appointments and practical support from voluntary organisations. Challenges for nurses included lack of training in patient screening and the extra workload caused by the assessments. The report on the pilot project concluded that involving elderly care specialists and using comprehensive geriatric assessments were useful approaches in the care of older cancer patients.

  1. Technology Education Tackles Energy Crisis.

    ERIC Educational Resources Information Center

    Cutshall, Sandy

    2002-01-01

    Describes the solar-hydrogen technologies at the East Valley Institute of Technology, the only technology center in the nations that offers this class. Describes its focus on solving the energy crisis. (JOW)

  2. Tackling cross-media pollution

    SciTech Connect

    Tangley, L.

    1985-02-01

    Environmental problems caused by cycling of pollutants from air to land to water have been recognized. Because of the lack of a holistic environmental approach, pollution control measures fail to account for the exposure of the ecosystem to pollutants anywhere other than the medium covered by that particular law. Examples presented in the paper include: acid rain and groundwater pollution; disposal of sludge from smokestack scrubbers; control of cadmium, 1,3-butadiene and chlorinated solvents. The efforts of the Environmental Protection Agency, the Electric Power Research Institute and industry in addressing these problems are described.

  3. The Research Status and Development Trend of Microbial Flocculant

    NASA Astrophysics Data System (ADS)

    Bao-jun, Jia; Jiang-mei, Yu

    Microbial flocculant is a kind of newly developed flocculant,For their biodegradability,high performance and harmless to environment,microbial flocculants has draw more and more attentions. This paper summarized a series of research and development on preparation of microbial flocculants. The factors that effect microbial flocculation and the optimization of the flocculation conditions were studied and discussed systematically. Also discussed the advantages and future trends of microbial flocculants in wastewater treatment.

  4. Relating nanomaterial properties and microbial toxicity

    SciTech Connect

    Suresh, Anil K; Pelletier, Dale A; Doktycz, Mitchel John

    2013-01-01

    Nanomaterials are meeting diverse needs in consumer and industrial products. Metal and metal oxide nanoparticles are among the most commonly used materials and their potential for adversely affecting environmental systems raises concern. Complex microbial consortia underlie environmental processes, and the potential toxicity of nanoparticles to microbial systems, and the consequent impacts on trophic balances, is particularly worrisome. The diverse array of metal and metal oxides, the different sizes and shapes that can be prepared and the variety of possible surface coatings complicate toxicity assessments. Further complicating toxicity interpretations are the diversity of microbial systems and their metabolic capabilities. Here, we review various studies focused on nanoparticle-microbial interactions in an effort to correlate the physical-chemical properties of engineered metal and metal oxide nanoparticles to their biological response. Gaining a predictive understanding of nanoparticle toxicity, based on the physical-chemical properties of the material, will be key to the design and responsible use of nanotechnologies. General conclusions regarding the parent material of the nanoparticle and nanoparticle s size and shape on potential toxicity can be made. However, the surface coating of the material, which can be altered significantly by environmental conditions, can ameliorate or promote microbial toxicity. Understanding nanoparticle transformations and how the nanoparticle surface can be designed to control toxicity represents a key area for further study. Additionally, the vast array of microbial species and their intrinsic metabolic capabilities complicates extrapolations of nanoparticle toxicity. A molecular-based understanding of the various microbial responses to nanoparticle-induced stress is needed. Ultimately, to interpret the effect and eventual fate of engineered materials in the environment, an understanding of the relationship between nanoparticle

  5. Controls on Microbial Transport in Subsurface Sediments

    NASA Astrophysics Data System (ADS)

    Szecsody, J. E.

    2005-12-01

    Laboratory-scale measurements of microbial transport indicate that most microbes attach to subsurface sediments. Given this attachment, it is unclear how microbes are transported significant distances in deep aquifers. It was hypothesized that attachment/detachment mechanisms are dynamic responses to nutrient availability, so that transport is dependent upon the presence/absence of electron donors and acceptors. For one microbial isolate of the Shewanella strain CN-32 there was high attachment in the presence of both electron donor and acceptor, and very little attachment if no donor or acceptor were present. In addition, CN-32 exhibited chemotatic movement through electron donor/acceptor gradients. A series of batch, 1-D homogeneous, 1-D heterogeneous, and 2-D heterogeneous experiments were conducted to quantify CN-32 Monod parameters and to assess the relative importance of simple attachment/detachment steps, dynamic growth/detachment steps, and chemotaxis. Three models included dual Monod kinetics for a single electron donor (lactate), two electron acceptors (dissolved oxygen and nitrate), and either: a) constant microbial attachment (adsorption), b) attachment linked to the presence of electron donor/acceptor, or c) chemotaxis. Simulations of batch experiments using quantified Monod parameters could not predict 1-D experimental results without accounting for microbial attachment. With constant input of electron donor/acceptors, microbial attachment could be well approximated assuming constant microbial adsorption. However, advection of input pulses of electron donor/acceptors resulted in much further downgradient migration, which could be simulated assuming an empirical growth/detachment reaction. The 2-D experimental system with microbes that received input pulses of electron donor/acceptors (idealized representation of an aquifer) showed that that both chemotaxis and the dynamic growth/detachment mechanisms were needed to approximate microbial movement over

  6. Microbial isotopic fractionation of perchlorate chlorine.

    PubMed

    Coleman, Max L; Ader, Magali; Chaudhuri, Swades; Coates, John D

    2003-08-01

    Perchlorate contamination can be microbially respired to innocuous chloride and thus can be treated effectively. However, monitoring a bioremediative strategy is often difficult due to the complexities of environmental samples. Here we demonstrate that microbial respiration of perchlorate results in a significant fractionation ( approximately -15 per thousand ) of the chlorine stable isotope composition of perchlorate. This can be used to quantify the extent of biotic degradation and to separate biotic from abiotic attenuation of this contaminant.

  7. An Economic Framework of Microbial Trade

    PubMed Central

    Mee, Michael T.

    2015-01-01

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

  8. Microbial Cellulose Utilization: Fundamentals and Biotechnology

    PubMed Central

    Lynd, Lee R.; Weimer, Paul J.; van Zyl, Willem H.; Pretorius, Isak S.

    2002-01-01

    Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for “consolidated bioprocessing” (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts. PMID:12209002

  9. Microbial Changes during Pregnancy, Birth, and Infancy

    PubMed Central

    Nuriel-Ohayon, Meital; Neuman, Hadar; Koren, Omry

    2016-01-01

    Several healthy developmental processes such as pregnancy, fetal development, and infant development include a multitude of physiological changes: weight gain, hormonal, and metabolic changes, as well as immune changes. In this review, we present an additional important factor which both influences and is affected by these physiological processes—the microbiome. We summarize the known changes in microbiota composition at a variety of body sites including gut, vagina, oral cavity, and placenta, throughout pregnancy, fetal development, and early childhood. There is still a lot to be discovered; yet several pieces of research point to the healthy desired microbial changes. Future research is likely to unravel precise roles and mechanisms of the microbiota in gestation; perhaps linking the metabolic, hormonal, and immune changes together. Although some research has started to link microbial dysbiosis and specific microbial populations with unhealthy pregnancy complications, it is important to first understand the context of the natural healthy microbial changes occurring. Until recently the placenta and developing fetus were considered to be germ free, containing no apparent microbiome. We present multiple study results showing distinct microbiota compositions in the placenta and meconium, alluding to early microbial colonization. These results may change dogmas and our overall understanding of the importance and roles of microbiota from the beginning of life. We further review the main factors shaping the infant microbiome—modes of delivery, feeding, weaning, and exposure to antibiotics. Taken together, we are starting to build a broader understanding of healthy vs. abnormal microbial alterations throughout major developmental time-points. PMID:27471494

  10. Microbial Signatures of Cadaver Gravesoil During Decomposition.

    PubMed

    Finley, Sheree J; Pechal, Jennifer L; Benbow, M Eric; Robertson, B K; Javan, Gulnaz T

    2016-04-01

    Genomic studies have estimated there are approximately 10(3)-10(6) bacterial species per gram of soil. The microbial species found in soil associated with decomposing human remains (gravesoil) have been investigated and recognized as potential molecular determinants for estimates of time since death. The nascent era of high-throughput amplicon sequencing of the conserved 16S ribosomal RNA (rRNA) gene region of gravesoil microbes is allowing research to expand beyond more subjective empirical methods used in forensic microbiology. The goal of the present study was to evaluate microbial communities and identify taxonomic signatures associated with the gravesoil human cadavers. Using 16S rRNA gene amplicon-based sequencing, soil microbial communities were surveyed from 18 cadavers placed on the surface or buried that were allowed to decompose over a range of decomposition time periods (3-303 days). Surface soil microbial communities showed a decreasing trend in taxon richness, diversity, and evenness over decomposition, while buried cadaver-soil microbial communities demonstrated increasing taxon richness, consistent diversity, and decreasing evenness. The results show that ubiquitous Proteobacteria was confirmed as the most abundant phylum in all gravesoil samples. Surface cadaver-soil communities demonstrated a decrease in Acidobacteria and an increase in Firmicutes relative abundance over decomposition, while buried soil communities were consistent in their community composition throughout decomposition. Better understanding of microbial community structure and its shifts over time may be important for advancing general knowledge of decomposition soil ecology and its potential use during forensic investigations.

  11. Microbial cellulose utilization: fundamentals and biotechnology.

    PubMed

    Lynd, Lee R; Weimer, Paul J; van Zyl, Willem H; Pretorius, Isak S

    2002-09-01

    Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for "consolidated bioprocessing" (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts.

  12. Cheese Microbial Risk Assessments — A Review

    PubMed Central

    Choi, Kyoung-Hee; Lee, Heeyoung; Lee, Soomin; Kim, Sejeong; Yoon, Yohan

    2016-01-01

    Cheese is generally considered a safe and nutritious food, but foodborne illnesses linked to cheese consumption have occurred in many countries. Several microbial risk assessments related to Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli infections, causing cheese-related foodborne illnesses, have been conducted. Although the assessments of microbial risk in soft and low moisture cheeses such as semi-hard and hard cheeses have been accomplished, it has been more focused on the correlations between pathogenic bacteria and soft cheese, because cheese-associated foodborne illnesses have been attributed to the consumption of soft cheeses. As a part of this microbial risk assessment, predictive models have been developed to describe the relationship between several factors (pH, Aw, starter culture, and time) and the fates of foodborne pathogens in cheese. Predictions from these studies have been used for microbial risk assessment as a part of exposure assessment. These microbial risk assessments have identified that risk increased in cheese with high moisture content, especially for raw milk cheese, but the risk can be reduced by preharvest and postharvest preventions. For accurate quantitative microbial risk assessment, more data including interventions such as curd cooking conditions (temperature and time) and ripening period should be available for predictive models developed with cheese, cheese consumption amounts and cheese intake frequency data as well as more dose-response models. PMID:26950859

  13. Pyrosequencing for Microbial Identification and Characterization

    PubMed Central

    Cummings, Patrick J.; Ahmed, Ray; Durocher, Jeffrey A.; Jessen, Adam; Vardi, Tamar; Obom, Kristina M.

    2013-01-01

    Pyrosequencing is a versatile technique that facilitates microbial genome sequencing that can be used to identify bacterial species, discriminate bacterial strains and detect genetic mutations that confer resistance to anti-microbial agents. The advantages of pyrosequencing for microbiology applications include rapid and reliable high-throughput screening and accurate identification of microbes and microbial genome mutations. Pyrosequencing involves sequencing of DNA by synthesizing the complementary strand a single base at a time, while determining the specific nucleotide being incorporated during the synthesis reaction. The reaction occurs on immobilized single stranded template DNA where the four deoxyribonucleotides (dNTP) are added sequentially and the unincorporated dNTPs are enzymatically degraded before addition of the next dNTP to the synthesis reaction. Detection of the specific base incorporated into the template is monitored by generation of chemiluminescent signals. The order of dNTPs that produce the chemiluminescent signals determines the DNA sequence of the template. The real-time sequencing capability of pyrosequencing technology enables rapid microbial identification in a single assay. In addition, the pyrosequencing instrument, can analyze the full genetic diversity of anti-microbial drug resistance, including typing of SNPs, point mutations, insertions, and deletions, as well as quantification of multiple gene copies that may occur in some anti-microbial resistance patterns. PMID:23995536

  14. Linking microbial carbon utilization with microbially-derived soil organic matter

    NASA Astrophysics Data System (ADS)

    Kallenbach, Cynthia M.; Grandy, A. Stuart

    2014-05-01

    Soil microbial communities are fundamental to plant C turnover, as all C inputs eventually pass through the microbial biomass. In turn, there is increasing evidence that this biomass accumulates as a significant portion of stable soil organic matter (SOM) via physiochemical interactions with the soil matrix. However, when exploring SOM dynamics, these two processes are often regarded as discrete from one another, despite potentially important linkages between microbial C utilization and the fate of that biomass C as SOM. Specifically, if stable SOM is largely comprised of microbial products, we need to better understand the soil C inputs that influence microbial biomass production and microbial C allocation. Microbial physiology, such as microbial growth efficiency (MGE), growth rate and turnover have direct influences on microbial biomass production and are highly sensitive to resource quality. Therefore, the importance of resource quality on SOM accumulation may not necessarily be a function of resistance to decay but the degree to which it optimizes microbial biomass production. To examine the relationship between microbial C utilization and microbial contributions to SOM, an ongoing 15-mo incubation experiment was set up using artificial, initially C- and microbial-free soils. Soil microcosms were constructed by mixing sand with either kaolinite or montmorillonite clays followed with a natural soil microbial inoculum. For both soil mineral treatments, weekly additions of glucose, cellobiose, or syringol are carried out, with an additional treatment of plant leachate to serve as a reference. This simplified system allows us to determine 1) if, in absence of plant-derived C, chemically complex SOM similar to natural soils can accumulate through the production of microbial residues and 2) how differences in C utilization of simple substrates, varying in energy yields, influence the quantity and chemistry of newly formed SOM. Over the course of the incubation, MGE

  15. Surface Chemistry Enhanced Microbial Bioelectrocatalysis

    PubMed Central

    Santoro, Carlo; Babanova, Sofia; Artyushkova, Kateryna; Cornejo, Jose’ A.; Ista, Linnea; Bretschger, Orianna; Marsili, Enrico; Atanassov, Plamen; Schuler, Andrew J.

    2016-01-01

    Self-assembled monolayers (SAMs) modified gold anodes are used in single chamber microbial fuel cells (SCMFC) for organics removal and electricity generation. Hydrophilic (−N(CH3)3+, −OH, −COOH) and hydrophobic (−CH3) SAMs are examined for their effect on bacterial attachment, current and power output. The different substratum chemistry affects both the current and power output and the community composition of the electrochemically active biofilm formed. Of the four SAM-modified anode tested, −N(CH3)3+ results in shortest start up time, highest single electrode polarization and power density, followed by −OH and –COOH SAMs. Hydrophobic SAM decreases bacteria attachment and anodes performance in comparison to hydrophilic SAMs. Electron transfer rate is faster on the N(CH3)3+-surface than on other surfaces, and correlates with a high abundance of δ-Proteobacteria, including electrochemically active species. A consortium of Clostridia and δ-Proteobacteria is found on all the anode surfaces, suggesting a synergistic cooperation under anodic conditions. PMID:26025340

  16. Microbial effects on colloidal agglomeration

    SciTech Connect

    Hersman, L.

    1995-11-01

    Colloidal particles are known to enhance the transport of radioactive metals through soil and rock systems. This study was performed to determine if a soil microorganism, isolated from the surface samples collected at Yucca Mountain, NV, could affect the colloidal properties of day particles. The agglomeration of a Wyoming bentonite clay in a sterile uninoculated microbial growth medium was compared to the agglomeration in the medium inoculated with a Pseudomonas sp. In a second experiment, microorganisms were cultured in the succinate medium for 50 h and removed by centrifugation. The agglomeration of the clay in this spent was compared to sterile uninoculated medium. In both experiments, the agglomeration of the clay was greater than that of the sterile, uninoculated control. Based on these results, which indicate that this microorganism enhanced the agglomeration of the bentonite clay, it is possible to say that in the presence of microorganisms colloidal movement through a rock matrix could be reduced because of an overall increase in the size of colloidal particle agglomerates. 32 refs.

  17. Microbial validation of vent filters.

    PubMed

    Robertson, J H; Frieben, W R

    1984-08-01

    The Upjohn Company uses filtration to remove microorganisms and particulates from air and other gases which may come in contact with sterile products. To validate the microbial retentivity of these filters, they were challenged with an aerosol of Bacillus subtilis var niger spores. An aerosol challenge was used because it more closely simulated the use for which these filters were designed. The test apparatus was constructed of autoclavable components using a jet-type nebulizer and heated air mixing tube. Characterization of the aerosol particle size distribution with a particle size analyzer demonstrated that 80% of the particles had a diameter of x 3.0 times;m and that the particles had a mean mass diameter of 1.9 times;m with a geometric standard deviation of 1.8 times;m. Studies conducted with aerosols of Bacillus subtilis var niger spores demonstrated that the test apparatus could recover ca. 50% of the spores that were aerosolized. Hydrophobic filters from various manufactures were challenged with an aerosol of at least 10(8) spores of Bacillus subtilis. All filters tested could retain at least 10(9) spores when physical integrity of the filter was verfield.

  18. Advanced microbial check valve development

    NASA Technical Reports Server (NTRS)

    Colombo, G. V.; Greenley, D. R.

    1980-01-01

    A flight certified assembly identified as a Microbial Check Valve (MCV) was developed and tested. The MCV is a canister packed with an iodinated anionic exchange resin. The device is used to destroy organisms in a water stream as the water passes through the device. The device is equally effective for fluid flow in either direction and its primary method of organism removal is killing rather than filtering. The MCV was successfully developed for the space shuttle to: disinfect fuel cell water; and prevent back contamination of the stored potable water supply. One version of the device consists of a high residual iodinated resin bed that imparts approximately 2 ppm of iodine to the fuel cell water as it flows to the potable water tanks. A second version of the device consists of a low residual iodinated resin bed. One of these low residual beds is located at each use port in the potable water system for the dual purpose of removing some iodine from the potable water as it is dispensed and also to prevent back contamination of the potable supply.

  19. Ohmic resistance affects microbial community and electrochemical kinetics in a multi-anode microbial electrochemical cell

    EPA Science Inventory

    Multi-anode microbial electrochemical cells (MXCs) are considered as one of the most promising configurations for scale-up of MXCs, but fundamental understanding of anode kinetics governing current density is limited in the MXCs. In this study we first assessed microbial communi...

  20. Astrobiological Significance of Microbial Extremophiles

    NASA Technical Reports Server (NTRS)

    Pikuta, Elena V.; Hoover, Richard B.

    2007-01-01

    The microflora of the cryosphere of planet Earth provides the best analogs for life forms that might be found in the permafrost or polar ice caps of Mars, near the surface of the cometary nuclei, or in the liquid water beneath and the ice crusts of icy moons of Jupiter and Saturn. The importance of study alkaliphilic microorganisms for astrobiology was enhanced by the findings of abundant carbonates and carbonate globules rimmed with possibly biogenic magnetites in association with the putative microfossils in the ALH84001 meteorite. Although the ALH84001 "nanofossils" were to small and simple to be unambiguously recognized as biogenic, they stimulated Astrobiology research and studies of microbial extremophiles and biomarkers in ancient rocks and meteorites. Recent studies of CI and CM carbonaceous meteorites have resulted in the detection of the well-preserved mineralized remains of coccoidal and filamentous microorganisms in cyanobacterial mats. Energy Dispersive X-ray Analysis has shown anomalous biogenic element ratios clearly indicating they are not recent biological contaminants. This paper reviews microbial extremophiles in context of their significance to Astrobiology. The study of halophilic microorganisms was started from work with saline soils and lakes, and one of the record of good growth for Haloferax mediterranei was shown at 30 percent NaC1. Although alkali-tolerant nitrifying bacteria had previously been reported, the first described alkaliphilic microorganism was the bacterium Streptococcus faecalis. Halophilic and alkaliphilic forms are relevant to conditions that might be found in closed impact basins and craters on Mars filled with evaporite deposits. The first obligately acidophilic bacterium described was Acidithiobacillus ferrooxydans (formally Thiobacillus ferrooxidans). Later thermophilic lithotrophic acidophiles were found, and the hyperacidophilic moderately thermophilic species of the genus Picrophilus were found to grow at negative p

  1. Sediment Interfaces: Ecotones on a Microbial Scale

    NASA Astrophysics Data System (ADS)

    Borchers, M. R.; Colwell, F. S.; D'Angelo, G.; Thurber, A. R.; Graw, M. F.

    2015-12-01

    Ecotones - transitions between different biomes - often support greater faunal diversity than the adjacent ecological systems. For subseafloor microorganisms, defined geological and chemical gradients have been shown to affect population sizes and community structure, but the role that sediment interfaces play is still unclear. Here, we test the hypothesis that zones of transition between two distinct sediment types increase microbial diversity and change community composition. Concurrently, we explore those factors that drive deep-subsurface microbial community structure (e.g., depth, interstitial water chemistry, methane concentrations, clay content). Samples from IODP Expedition 349 - South China Sea Tectonics - had interfaces of either ash/clay or turbidite/clay boundaries sampled , DNA extracted, and the 16S rRNA gene analyzed on an Illumina MiSeq platform. Initial analyses reveal that microbial communities in sediment samples are distinct from communities in drilling fluid, indicating that contamination is unlikely. In four of the eight complete interfaces currently analyzed we found an increase in diversity (based on the chao1 index), in certain cases doubling the diversity of the adjacent rock types. The pattern was not uniform across all interfaces. While some posit that ecotones provide a mixing of the two adjacent communities, we were surprised to find an abundance (mean = 392 OTUs) of unique microbial taxa within the ecotone itself when compared to adjacent sediment (mean=282 unique OTUs). Thus while diversity was not uniformly increased in ecotones, the interface led to divergent microbial communities that were not simply mixtures of those adjacent. We will discuss the ability of abiotic factors in explaining the among ecotone variance that we observed. Our investigation helps to characterize the factors that drive microbial community structure of the subseafloor while highlighting the need to focus on habitat heterogeneity at a scale pertinent to

  2. Induced polarization response of microbial induced sulfideprecipitation

    SciTech Connect

    Ntarlagiannis, Dimitrios; Williams, Kenneth Hurst; Slater, Lee; Hubbard, Susan

    2004-06-04

    A laboratory scale experiment was conducted to examine the use of induced polarization and electrical conductivity to monitor microbial induced sulfide precipitation under anaerobic conditions in sand filled columns. Three columns were fabricated; one for electrical measurements, one for geochemical sampling and a third non-inoculated column was used as a control. A continual upward flow of nutrients and metals in solution was established in each column. Desulfovibrio vulgaris microbes were injected into the middle of the geochemical and electrical columns. Iron and zinc sulfides precipitated along a microbial action front as a result of sulfate reduction due by Desulfovibrio vulgaris. The precipitation front initially developed near the microbial injection location, and subsequently migrated towards the nutrient inlet, as a result of chemotaxis by Desulfovibrio vulgaris. Sampling during and subsequent to the experiment revealed spatiotemporal changes in the biogeochemical measurements associated with microbial sulfate reduction. Conductivity measurements were insensitive to all biogeochemical changes occurred within the column. Changes in the IP response (of up to 14 mrad)were observed to coincide in place and in time with the active microbe respiration/sulfide precipitation front as determined from geochemical sampling. The IP response is correlated with the lactate concentration gradient, an indirect measurement of microbial metabolism, suggesting the potential of IP as a method for monitoring microbial respiration/activity. Post experimental destructive sample analysis and SEM imaging verified the geochemical results and supported our hypothesis that microbe induced sulfide precipitation is directly detectable using electrical methods. Although the processes not fully understood, the IP response appears to be sensitive to this anaerobic microbial precipitation, suggesting a possible novel application for the IP method.

  3. Two-stage microbial community experimental design.

    PubMed

    Tickle, Timothy L; Segata, Nicola; Waldron, Levi; Weingart, Uri; Huttenhower, Curtis

    2013-12-01

    Microbial community samples can be efficiently surveyed in high throughput by sequencing markers such as the 16S ribosomal RNA gene. Often, a collection of samples is then selected for subsequent metagenomic, metabolomic or other follow-up. Two-stage study design has long been used in ecology but has not yet been studied in-depth for high-throughput microbial community investigations. To avoid ad hoc sample selection, we developed and validated several purposive sample selection methods for two-stage studies (that is, biological criteria) targeting differing types of microbial communities. These methods select follow-up samples from large community surveys, with criteria including samples typical of the initially surveyed population, targeting specific microbial clades or rare species, maximizing diversity, representing extreme or deviant communities, or identifying communities distinct or discriminating among environment or host phenotypes. The accuracies of each sampling technique and their influences on the characteristics of the resulting selected microbial community were evaluated using both simulated and experimental data. Specifically, all criteria were able to identify samples whose properties were accurately retained in 318 paired 16S amplicon and whole-community metagenomic (follow-up) samples from the Human Microbiome Project. Some selection criteria resulted in follow-up samples that were strongly non-representative of the original survey population; diversity maximization particularly undersampled community configurations. Only selection of intentionally representative samples minimized differences in the selected sample set from the original microbial survey. An implementation is provided as the microPITA (Microbiomes: Picking Interesting Taxa for Analysis) software for two-stage study design of microbial communities.

  4. Microbial Formation of Manganese Oxides

    PubMed Central

    Greene, Anthony C.; Madgwick, John C.

    1991-01-01

    Microbial manganese oxidation was demonstrated at high Mn2+ concentrations (5 g/liter) in bacterial cultures in the presence of a microalga. The structure of the oxide produced varied depending on the bacterial strain and mode of culture. A nonaxenic, acid-tolerant microalga, a Chlamydomonas sp., was found to mediate formation of manganite (γ-MnOOH). Bacteria isolated from associations with crude cultures of this alga grown in aerated bioreactors formed disordered γ-MnO2 from Mn2+ at concentrations of 5 g/liter over 1 month, yielding 3.3 g of a semipure oxide per liter. All algal-bacterial cultures removed Mn2+ from solution, but only those with the highest removal rates formed an insoluble oxide. While the alga was an essential component of the reaction, a Pseudomonas sp. was found to be primarily responsible for the formation of a manganese precipitate. Medium components—algal biomass and urea—showed optima at 5.7 and 10 g/liters, respectively. The scaled-up culture (50 times) gave a yield of 22.3 g (53 mg/liter/day from a 15-liter culture) of semipure disordered γ-MnO2, identified by X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy, and had a manganese oxide O/Mn ratio of 1.92. The Mn(IV) content in the oxide was low (30.5%) compared with that of mined or chemically formed γ-MnO2 (ca. 50%). The shortfall in the bacterial oxide manganese content was due to biological and inorganic contaminants. FTIR spectroscopy, transmission electron microscopy, and electron diffraction studies have identified manganite as a likely intermediate product in the formation of disordered γ-MnO2. PMID:16348459

  5. Molecular biology of microbial ureases.

    PubMed Central

    Mobley, H L; Island, M D; Hausinger, R P

    1995-01-01

    progress in our understanding of the molecular biology of microbial ureases is reviewed. PMID:7565414

  6. Microbial Community Analysis of a Single Chamber Microbial Fuel Cell Using Potato Wastewater

    SciTech Connect

    Zhen Li; Rishika Haynes; Eugene Sato; Malcolm Shields; Yoshiko Fujita; Chikashi Sato

    2014-04-01

    Microbial fuel cells (MFCs) convert chemical energy to electrical energy via bioelectrochemical reactions mediated by microorganisms. We investigated the diversity of the microbial community in an air cathode single chamber MFC that utilized potato-process wastewater as substrate. Terminal Restriction Fragment Length Polymorphism (T-RFLP) results indicated that the bacterial communities on the anode, cathode, control electrode, and MFC bulk fluid were similar, but differed dramatically from that of the anaerobic domestic sludge and potato wastewater inoculum. The 16S rDNA sequencing results showed that microbial species detected on the anode were predominantly within the phyla of Proteobacteria, Firmicutes, and Bacteroidetes. Fluorescent microscopy results indicated that there was a clear enhancement of biofilm formation on the anode. Results of this study could help improve understanding of the complexity of microbial communities and optimize the microbial composition for generating electricity by MFCs that utilize potato wastewater.

  7. Microbial community analysis of a single chamber microbial fuel cell using potato wastewater.

    PubMed

    Li, Zhen; Haynes, Rishika; Sato, Eugene; Shields, Malcolm S; Fujita, Yoshiko; Sato, Chikashi

    2014-04-01

    Microbial fuel cells (MFCs) convert chemical energy to electrical energy via bio-electrochemical reactions mediated by microorganisms. This study investigated the diversity of the microbial community in an air cathode single chamber MFC that used potato-process wastewater as substrate. Terminal restriction fragment length polymorphism results indicated that the bacterial communities on the anode, cathode, control electrode, and MFC bulk fluid were similar, but differed dramatically from that of the anaerobic domestic sludge and potato wastewater inoculum. The 16S ribosomal DNA sequencing results showed that microbial species detected on the anode were predominantly within the phyla of Proteobacteria, Firmicutes, and Bacteroidetes. Fluorescent microscopy results indicated that there was a clear enhancement of biofilm formation on the anode. Results of this study could help improve understanding of the complexity of microbial communities and optimize the microbial composition for generating electricity by MFCs that use potato wastewater.

  8. A Theoretical Reassessment of Microbial Maintenance and Implications for Microbial Ecology Modeling

    SciTech Connect

    Wang, Gangsheng; Post, Wilfred M

    2012-01-01

    We attempted to reconcile three microbial maintenance models (Herbert, Pirt, and Compromise) through a critical reassessment. We provided a rigorous proof that the true growth yield coefficient (YG) is the ratio of the specific maintenance rate (a in Herbert) to the maintenance coefficient (m in Pirt). Other findings from this study include: (1) the Compromise model is identical to the Herbert for computing microbial growth and substrate consumption, but it expresses the dependence of maintenance on both microbial biomass and substrate; (2) the maximum specific growth rate in the Herbert ( max,H) is higher than those in the other two models ( max,P and max,C), and the difference is the physiological maintenance factor (mq = a); and (3) the overall maintenance coefficient (mT) is more sensitive to mq than to the specific growth rate ( G) and YG. Our critical reassessment of microbial maintenance provides a new approach for quantifying some important components in soil microbial ecology models.

  9. Sulfuric Acid Speleogenesis: Microbial Karst and Microbial Crust

    NASA Astrophysics Data System (ADS)

    Engel, A. S.; Bennett, P. C.; Stern, L. A.

    2001-12-01

    Sulfuric acid speleogenesis is a fundamental mechanism of karst formation, and is potentially responsible for the formation of some of the most extensive cave systems yet discovered. Speleogenesis occurs from the rapid dissolution of the host limestone by sulfuric acid produced from biotic and abiotic sulfide oxidation, and with the release of carbon dioxide, secondary gypsum crusts form. This crust develops predominately on the cave walls, often preserving original bedding indicators, until it finally collapses under its own weight to expose fresh limestone for dissolution. While this general speleogenetic process can be inferred from secondary residues in some caves, directly observing this process is difficult, and involves entry into an extreme environment with toxic atmospheres and low pH solutions. Kane Cave, Big Horn County, WY, offers the unique opportunity to study microbe-rock interactions directly. Kane Cave presently contains 3 springs that discharge hydrogen sulfide-rich waters, supporting thick subaqueous mats of diverse microbial communities in the stream passage. Condensation droplets and elemental sulfur form on subaerially exposed gypsum surfaces. Droplets have an average pH of 1.7, and are dominated by dissolved sulfate, Ca, Mg, Al, and Si, with minor Sr and Fe, and trace Mn and U. SEM and EDS examination of the crusts reveal the presence of C, O, and S, as well as authigenic, doubly-terminated quartz crystals. An average δ 13C value of -36 ‰ suggests that the crusts are biogenic and are composed of chemoautotrophic microorganisms. Enrichment cultures of biofilms and acid droplets rapidly produce sulfuric acid, demonstrating the dominance of sulfur-oxidizing bacteria. Colonization of gypsum surfaces by acidophilic microorganisms enhances acid dissolution of the limestone, and hence the growth of the cave itself. Limestone dissolution also results in mineralized crusts and biofilms that accumulate insoluble residues, which serve as sources of

  10. Non-microbial methane emissions from soils

    NASA Astrophysics Data System (ADS)

    Wang, Bin; Hou, Longyu; Liu, Wei; Wang, Zhiping

    2013-12-01

    Traditionally, methane (CH4) is anaerobically formed by methanogenic archaea. However, non-microbial CH4 can also be produced from geologic processes, biomass burning, animals, plants, and recently identified soils. Recognition of non-microbial CH4 emissions from soils remains inadequate. To better understand this phenomenon, a series of laboratory incubations were conducted to examine effects of temperature, water, and hydrogen peroxide (H2O2) on CH4 emissions under both aerobic and anaerobic conditions using autoclaved (30 min, 121 °C) soils and aggregates (>2000 μm, A1; 2000-250 μm, A2; 250-53 μm, M1; and <53 μm, M2). Results show that applying autoclaving to pre-treat soils is effective to inhibit methanogenic activity, ensuring the CH4 emitted being non-microbial. Responses of non-microbial CH4 emissions to temperature, water, and H2O2 were almost identical between aerobic and anaerobic conditions. Increasing temperature, water of proper amount, and H2O2 could significantly enhance CH4 emissions. However, the emission rates were inhibited and enhanced by anaerobic conditions without and with the existence of H2O2, respectively. As regards the aggregates, aggregate-based emission presented an order of M1 > A2 > A1 > M2 and C-based emission an order of M2 > M1 > A1 > A2, demonstrating that both organic carbon quantity and property are responsible for CH4 emissions from soils at the scale of aggregate. Whole soil-based order of A2 > A1 > M1 > M2 suggests that non-microbial CH4 release from forest soils is majorly contributed by macro-aggregates (i.e., >250 μm). The underlying mechanism is that organic matter through thermal treatment, photolysis, or reactions with free radicals produce CH4, which, in essence, is identical with mechanisms of other non-microbial sources, indicating that non-microbial CH4 production may be a widespread phenomenon in nature. This work further elucidates the importance of non-microbial CH4 formation which should be distinguished

  11. 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

  12. Microbial hotspots and hot moments in soil

    NASA Astrophysics Data System (ADS)

    Kuzyakov, Yakov; Blagodatskaya, Evgenia

    2015-04-01

    Soils are the most heterogeneous parts of the biosphere, with an extremely high differentiation of properties and processes within nano- to macroscales. The spatial and temporal heterogeneity of input of labile organics by plants creates microbial hotspots over short periods of time - the hot moments. We define microbial hotspots as small soil volumes with much faster process rates and much more intensive interactions compared to the average soil conditions. Such hotspots are found in the rhizosphere, detritusphere, biopores (including drilosphere) and on aggregate surfaces, but hotspots are frequently of mixed origin. Hot moments are short-term events or sequences of events inducing accelerated process rates as compared to the averaged rates. Thus, hotspots and hot moments are defined by dynamic characteristics, i.e. by process rates. For this hotspot concept we extensively reviewed and examined the localization and size of hotspots, spatial distribution and visualization approaches, transport of labile C to and from hotspots, lifetime and process intensities, with a special focus on process rates and microbial activities. The fraction of active microorganisms in hotspots is 2-20 times higher than in the bulk soil, and their specific activities (i.e. respiration, microbial growth, mineralization potential, enzyme activities, RNA/DNA ratio) may also be much higher. The duration of hot moments in the rhizosphere is limited and is controlled by the length of the input of labile organics. It can last a few hours up to a few days. In the detritusphere, however, the duration of hot moments is regulated by the output - by decomposition rates of litter - and lasts for weeks and months. Hot moments induce succession in microbial communities and intense intra- and interspecific competition affecting C use efficiency, microbial growth and turnover. The faster turnover and lower C use efficiency in hotspots counterbalances the high C inputs, leading to the absence of strong

  13. Humans differ in their personal microbial cloud

    PubMed Central

    Altrichter, Adam E.; Bateman, Ashley C.; Stenson, Jason; Brown, GZ; Green, Jessica L.; Bohannan, Brendan J.M.

    2015-01-01

    Dispersal of microbes between humans and the built environment can occur through direct contact with surfaces or through airborne release; the latter mechanism remains poorly understood. Humans emit upwards of 106 biological particles per hour, and have long been known to transmit pathogens to other individuals and to indoor surfaces. However it has not previously been demonstrated that humans emit a detectible microbial cloud into surrounding indoor air, nor whether such clouds are sufficiently differentiated to allow the identification of individual occupants. We used high-throughput sequencing of 16S rRNA genes to characterize the airborne bacterial contribution of a single person sitting in a sanitized custom experimental climate chamber. We compared that to air sampled in an adjacent, identical, unoccupied chamber, as well as to supply and exhaust air sources. Additionally, we assessed microbial communities in settled particles surrounding each occupant, to investigate the potential long-term fate of airborne microbial emissions. Most occupants could be clearly detected by their airborne bacterial emissions, as well as their contribution to settled particles, within 1.5–4 h. Bacterial clouds from the occupants were statistically distinct, allowing the identification of some individual occupants. Our results confirm that an occupied space is microbially distinct from an unoccupied one, and demonstrate for the first time that individuals release their own personalized microbial cloud. PMID:26417541

  14. 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.

  15. Microbial biodiversity in glacier-fed streams.

    PubMed

    Wilhelm, Linda; Singer, Gabriel A; Fasching, Christina; Battin, Tom J; Besemer, Katharina

    2013-08-01

    While glaciers become increasingly recognised as a habitat for diverse and active microbial communities, effects of their climate change-induced retreat on the microbial ecology of glacier-fed streams remain elusive. Understanding the effect of climate change on microorganisms in these ecosystems is crucial given that microbial biofilms control numerous stream ecosystem processes with potential implications for downstream biodiversity and biogeochemistry. Here, using a space-for-time substitution approach across 26 Alpine glaciers, we show how microbial community composition and diversity, based on 454-pyrosequencing of the 16S rRNA gene, in biofilms of glacier-fed streams may change as glaciers recede. Variations in streamwater geochemistry correlated with biofilm community composition, even at the phylum level. The most dominant phyla detected in glacial habitats were Proteobacteria, Bacteroidetes, Actinobacteria and Cyanobacteria/chloroplasts. Microorganisms from ice had the lowest α diversity and contributed marginally to biofilm and streamwater community composition. Rather, streamwater apparently collected microorganisms from various glacial and non-glacial sources forming the upstream metacommunity, thereby achieving the highest α diversity. Biofilms in the glacier-fed streams had intermediate α diversity and species sorting by local environmental conditions likely shaped their community composition. α diversity of streamwater and biofilm communities decreased with elevation, possibly reflecting less diverse sources of microorganisms upstream in the catchment. In contrast, β diversity of biofilms decreased with increasing streamwater temperature, suggesting that glacier retreat may contribute to the homogenisation of microbial communities among glacier-fed streams.

  16. Anthropogenic perturbations in marine microbial communities.

    PubMed

    Nogales, Balbina; Lanfranconi, Mariana P; Piña-Villalonga, Juana M; Bosch, Rafael

    2011-03-01

    Human activities impact marine ecosystems at a global scale and all levels of complexity of life. Despite their importance as key players in ecosystem processes, the stress caused to microorganisms has been greatly neglected. This fact is aggravated by difficulties in the analysis of microbial communities and their high diversity, making the definition of patterns difficult. In this review, we discuss the effects of nutrient increase, pollution by organic chemicals and heavy metals and the introduction of antibiotics and pathogens into the environment. Microbial communities respond positively to nutrients and chemical pollution by increasing cell numbers. There are also significant changes in community composition, increases in diversity and high temporal variability. These changes, which evidence the modification of the environmental conditions due to anthropogenic stress, usually alter community functionality, although this aspect has not been explored in depth. Altered microbial communities in human-impacted marine environments can in turn have detrimental effects on human health (i.e. spread of pathogens and antibiotic resistance). New threats to marine ecosystems, i.e. related to climate change, could also have an impact on microbial communities. Therefore, an effort dedicated to analyse the microbial compartment in detail should be made when studying the impact of anthropogenic activities on marine ecosystems.

  17. Microbial biodiversity in glacier-fed streams

    PubMed Central

    Wilhelm, Linda; Singer, Gabriel A; Fasching, Christina; Battin, Tom J; Besemer, Katharina

    2013-01-01

    While glaciers become increasingly recognised as a habitat for diverse and active microbial communities, effects of their climate change-induced retreat on the microbial ecology of glacier-fed streams remain elusive. Understanding the effect of climate change on microorganisms in these ecosystems is crucial given that microbial biofilms control numerous stream ecosystem processes with potential implications for downstream biodiversity and biogeochemistry. Here, using a space-for-time substitution approach across 26 Alpine glaciers, we show how microbial community composition and diversity, based on 454-pyrosequencing of the 16S rRNA gene, in biofilms of glacier-fed streams may change as glaciers recede. Variations in streamwater geochemistry correlated with biofilm community composition, even at the phylum level. The most dominant phyla detected in glacial habitats were Proteobacteria, Bacteroidetes, Actinobacteria and Cyanobacteria/chloroplasts. Microorganisms from ice had the lowest α diversity and contributed marginally to biofilm and streamwater community composition. Rather, streamwater apparently collected microorganisms from various glacial and non-glacial sources forming the upstream metacommunity, thereby achieving the highest α diversity. Biofilms in the glacier-fed streams had intermediate α diversity and species sorting by local environmental conditions likely shaped their community composition. α diversity of streamwater and biofilm communities decreased with elevation, possibly reflecting less diverse sources of microorganisms upstream in the catchment. In contrast, β diversity of biofilms decreased with increasing streamwater temperature, suggesting that glacier retreat may contribute to the homogenisation of microbial communities among glacier-fed streams. PMID:23486246

  18. Rapid quantitative profiling of complex microbial populations

    PubMed Central

    Palmer, Chana; Bik, Elisabeth M.; Eisen, Michael B.; Eckburg, Paul B.; Sana, Theodore R.; Wolber, Paul K.; Relman, David A.; Brown, Patrick O.

    2006-01-01

    Diverse and complex microbial ecosystems are found in virtually every environment on earth, yet we know very little about their composition and ecology. Comprehensive identification and quantification of the constituents of these microbial communities—a ‘census’—is an essential foundation for understanding their biology. To address this problem, we developed, tested and optimized a DNA oligonucleotide microarray composed of 10 462 small subunit (SSU) ribosomal DNA (rDNA) probes (7167 unique sequences) selected to provide quantitative information on the taxonomic composition of diverse microbial populations. Using our optimized experimental approach, this microarray enabled detection and quantification of individual bacterial species present at fractional abundances of <0.1% in complex synthetic mixtures. The estimates of bacterial species abundance obtained using this microarray are similar to those obtained by phylogenetic analysis of SSU rDNA sequences from the same samples—the current ‘gold standard’ method for profiling microbial communities. Furthermore, probes designed to represent higher order taxonomic groups of bacterial species reliably detected microbes for which there were no species-specific probes. This simple, rapid microarray procedure can be used to explore and systematically characterize complex microbial communities, such as those found within the human body. PMID:16407321

  19. Microbial Diversity of Impact-Generated Habitats.

    PubMed

    Pontefract, Alexandra; Osinski, Gordon R; Cockell, Charles S; Southam, Gordon; McCausland, Phil J A; Umoh, Joseph; Holdsworth, David W

    2016-10-01

    Impact-generated lithologies have recently been identified as viable and important microbial habitats, especially within cold and arid regions such as the polar deserts on Earth. These unique habitats provide protection from environmental stressors, such as freeze-thaw events, desiccation, and UV radiation, and act to trap aerially deposited detritus within the fissures and pore spaces, providing necessary nutrients for endoliths. This study provides the first culture-independent analysis of the microbial community structure within impact-generated lithologies in a Mars analog environment, involving the analysis of 44,534 16S rRNA sequences from an assemblage of 21 rock samples that comprises three shock metamorphism categories. We find that species diversity increases (H = 2.4-4.6) with exposure to higher shock pressures, which leads to the development of three distinct populations. In each population, Actinobacteria were the most abundant (41%, 65%, and 59%), and the dominant phototrophic taxa came from the Chloroflexi. Calculated porosity (a function of shock metamorphism) for these samples correlates (R(2) = 0.62) with inverse Simpson indices, accounting for overlap in populations in the higher shock levels. The results of our study show that microbial diversity is tied to the amount of porosity in the target substrate (as a function of shock metamorphism), resulting in the formation of distinct microbial populations. Key Words: Microbial diversity-Endoliths-Impact melt-rocks-Mars-Astrobiology. Astrobiology 16, 775-786.

  20. Environmental Regulation of Microbial Community Structure

    NASA Technical Reports Server (NTRS)

    Bebout, Leslie; DesMarais, D.; Heyenga, G.; Nelson, F.; DeVincenzi, D. (Technical Monitor)

    2002-01-01

    Most naturally occurring microbes live in complex microbial communities consisting of thousands of phylotypes of microorganisms living in close proximity. Each of these draws nutrients from the environment and releases metabolic waste products, which may in turn serve as substrates for other microbial groups. Gross environmental changes, such as irradiance level, hydrodynamic flow regime, temperature or water chemistry can directly affect the productivity of some community members, which in turn will affect other dependent microbial populations and rate processes. As a first step towards the development of "standard" natural communities of microorganisms for a variety of potential NASA applications, we are measuring biogeochemical cycling in artificially structured communities of microorganisms, created using natural microbial mat communities as inoculum. The responses of these artificially assembled communities of microorganisms to controlled shifts in ecosystem incubation conditions is being determined. This research requires close linking of environmental monitoring, with community composition in a closed and controlled incubation setting. We are developing new incubation chamber designs to allow for this integrated approach to examine the interplay between environmental conditions, microbial community composition and biogeochemical processes.

  1. Biogeochemistry of microbial coal-bed methane

    USGS Publications Warehouse

    Strc, D.; Mastalerz, Maria; Dawson, K.; MacAlady, J.; Callaghan, A.V.; Wawrik, B.; Turich, C.; Ashby, M.

    2011-01-01

    Microbial methane accumulations have been discovered in multiple coal-bearing basins over the past two decades. Such discoveries were originally based on unique biogenic signatures in the stable isotopic composition of methane and carbon dioxide. Basins with microbial methane contain either low-maturity coals with predominantly microbial methane gas or uplifted coals containing older, thermogenic gas mixed with more recently produced microbial methane. Recent advances in genomics have allowed further evaluation of the source of microbial methane, through the use of high-throughput phylogenetic sequencing and fluorescent in situ hybridization, to describe the diversity and abundance of bacteria and methanogenic archaea in these subsurface formations. However, the anaerobic metabolism of the bacteria breaking coal down to methanogenic substrates, the likely rate-limiting step in biogenic gas production, is not fully understood. Coal molecules are more recalcitrant to biodegradation with increasing thermal maturity, and progress has been made in identifying some of the enzymes involved in the anaerobic degradation of these recalcitrant organic molecules using metagenomic studies and culture enrichments. In recent years, researchers have attempted lab and subsurface stimulation of the naturally slow process of methanogenic degradation of coal. Copyright ?? 2011 by Annual Reviews. All rights reserved.

  2. 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.

  3. 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.

  4. High-resolution phylogenetic microbial community profiling

    PubMed Central

    Singer, Esther; Bushnell, Brian; Coleman-Derr, Devin; Bowman, Brett; Bowers, Robert M; Levy, Asaf; Gies, Esther A; Cheng, Jan-Fang; Copeland, Alex; Klenk, Hans-Peter; Hallam, Steven J; Hugenholtz, Philip; Tringe, Susannah G; Woyke, Tanja

    2016-01-01

    Over the past decade, high-throughput short-read 16S rRNA gene amplicon sequencing has eclipsed clone-dependent long-read Sanger sequencing for microbial community profiling. The transition to new technologies has provided more quantitative information at the expense of taxonomic resolution with implications for inferring metabolic traits in various ecosystems. We applied single-molecule real-time sequencing for microbial community profiling, generating full-length 16S rRNA gene sequences at high throughput, which we propose to name PhyloTags. We benchmarked and validated this approach using a defined microbial community. When further applied to samples from the water column of meromictic Sakinaw Lake, we show that while community structures at the phylum level are comparable between PhyloTags and Illumina V4 16S rRNA gene sequences (iTags), variance increases with community complexity at greater water depths. PhyloTags moreover allowed less ambiguous classification. Last, a platform-independent comparison of PhyloTags and in silico generated partial 16S rRNA gene sequences demonstrated significant differences in community structure and phylogenetic resolution across multiple taxonomic levels, including a severe underestimation in the abundance of specific microbial genera involved in nitrogen and methane cycling across the Lake's water column. Thus, PhyloTags provide a reliable adjunct or alternative to cost-effective iTags, enabling more accurate phylogenetic resolution of microbial communities and predictions on their metabolic potential. PMID:26859772

  5. Microbial interactions: ecology in a molecular perspective.

    PubMed

    Braga, Raíssa Mesquita; Dourado, Manuella Nóbrega; Araújo, Welington Luiz

    2016-12-01

    The microorganism-microorganism or microorganism-host interactions are the key strategy to colonize and establish in a variety of different environments. These interactions involve all ecological aspects, including physiochemical changes, metabolite exchange, metabolite conversion, signaling, chemotaxis and genetic exchange resulting in genotype selection. In addition, the establishment in the environment depends on the species diversity, since high functional redundancy in the microbial community increases the competitive ability of the community, decreasing the possibility of an invader to establish in this environment. Therefore, these associations are the result of a co-evolution process that leads to the adaptation and specialization, allowing the occupation of different niches, by reducing biotic and abiotic stress or exchanging growth factors and signaling. Microbial interactions occur by the transference of molecular and genetic information, and many mechanisms can be involved in this exchange, such as secondary metabolites, siderophores, quorum sensing system, biofilm formation, and cellular transduction signaling, among others. The ultimate unit of interaction is the gene expression of each organism in response to an environmental (biotic or abiotic) stimulus, which is responsible for the production of molecules involved in these interactions. Therefore, in the present review, we focused on some molecular mechanisms involved in the microbial interaction, not only in microbial-host interaction, which has been exploited by other reviews, but also in the molecular strategy used by different microorganisms in the environment that can modulate the establishment and structuration of the microbial community.

  6. Humans differ in their personal microbial cloud.

    PubMed

    Meadow, James F; Altrichter, Adam E; Bateman, Ashley C; Stenson, Jason; Brown, G Z; Green, Jessica L; Bohannan, Brendan J M

    2015-01-01

    Dispersal of microbes between humans and the built environment can occur through direct contact with surfaces or through airborne release; the latter mechanism remains poorly understood. Humans emit upwards of 10(6) biological particles per hour, and have long been known to transmit pathogens to other individuals and to indoor surfaces. However it has not previously been demonstrated that humans emit a detectible microbial cloud into surrounding indoor air, nor whether such clouds are sufficiently differentiated to allow the identification of individual occupants. We used high-throughput sequencing of 16S rRNA genes to characterize the airborne bacterial contribution of a single person sitting in a sanitized custom experimental climate chamber. We compared that to air sampled in an adjacent, identical, unoccupied chamber, as well as to supply and exhaust air sources. Additionally, we assessed microbial communities in settled particles surrounding each occupant, to investigate the potential long-term fate of airborne microbial emissions. Most occupants could be clearly detected by their airborne bacterial emissions, as well as their contribution to settled particles, within 1.5-4 h. Bacterial clouds from the occupants were statistically distinct, allowing the identification of some individual occupants. Our results confirm that an occupied space is microbially distinct from an unoccupied one, and demonstrate for the first time that individuals release their own personalized microbial cloud.

  7. Microbial shaping of sedimentary wrinkle structures

    NASA Astrophysics Data System (ADS)

    Mariotti, G.; Pruss, S. B.; Perron, J. T.; Bosak, T.

    2014-10-01

    Wrinkle structures on sandy bed surfaces were present in some of the earliest sedimentary environments, but are rare in modern environments. These enigmatic millimetre- to centimetre-scale ridges or pits are particularly common in sediments that harbour trace fossils and imprints of early animals, and appeared in the aftermath of some large mass extinctions. Wrinkle structures have been interpreted as possible remnants of microbial mats, but the formation mechanism and associated palaeoenvironmental and palaeoecological implications of these structures remain debated. Here we show that microbial aggregates can form wrinkle structures on a bed of bare sand in wave tank experiments. Waves with a small orbital amplitude at the bed surface do not move sand grains directly. However, they move millimetre-size, light microbial fragments and thereby produce linear sand ridges and rounded scour pits at the wavelengths observed in nature within hours. We conclude that wrinkle structures are morphological biosignatures that form at the sediment-water interface in wave-dominated environments, and not beneath microbial mats as previously thought. During early animal evolution, grazing by eukaryotic organisms may have temporarily increased the abundance of microbial fragments and thus the production of wrinkle structures.

  8. HIV legal precedent useful for microbial forensics.

    PubMed

    Budowle, Bruce; Harmon, Rockne

    2005-08-01

    The field of microbial forensics was formalized because of the need for attribution in events where a bioweapon has been used. Microbial forensics has its origins in traditional forensics, microbiology, and epidemiology. Microbial forensics can be defined as a scientific discipline dedicated to analyzing evidence for attribution purposes from a bioterrorism act, biocrime, hoax, or inadvertent microorganism/toxin release. This is a very challenging task, since there are myriad microorganisms that can pose a threat, and analytical methods need to be used reliably. The Scientific Working Group on Microbial Genetics and Forensics (SWGMGF) has addressed some quality assurance and control issues, and particularly validation criteria (focusing on preliminary validation) due to the dynamic nature of evolving investigations. Unique identification of a microorganism may never be possible. Yet, qualitative and/or quantitative assessments of the evidence can be made. One approach to provide direction on gaps in the microbial forensics effort is to perform an end-to-end retrospective analysis of past cases. As an example, the case of a gastroenterologist who was accused of second degree attempted murder of his paramour using HIV as the weapon was reviewed. The scientific evaluation involves epidemiology, molecular biology, phylogenetics, and legal deliberations.

  9. Microbial enhanced oil recovery and compositions therefor

    DOEpatents

    Bryant, Rebecca S.

    1990-01-01

    A method is provided for microbial enhanced oil recovery, wherein a combination of microorganisms is empirically formulated based on survivability under reservoir conditions and oil recovery efficiency, such that injection of the microbial combination may be made, in the presence of essentially only nutrient solution, directly into an injection well of an oil bearing reservoir having oil present at waterflood residual oil saturation concentration. The microbial combination is capable of displacing residual oil from reservoir rock, which oil may be recovered by waterflooding without causing plugging of the reservoir rock. Further, the microorganisms are capable of being transported through the pores of the reservoir rock between said injection well and associated production wells, during waterflooding, which results in a larger area of the reservoir being covered by the oil-mobilizing microorganisms.

  10. Cancer-promoting effects of microbial dysbiosis.

    PubMed

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

    2014-10-01

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

  11. Epithelial Intermediate Filaments: Guardians against Microbial Infection?

    PubMed Central

    Geisler, Florian; Leube, Rudolf E.

    2016-01-01

    Intermediate filaments are abundant cytoskeletal components of epithelial tissues. They have been implicated in overall stress protection. A hitherto poorly investigated area of research is the function of intermediate filaments as a barrier to microbial infection. This review summarizes the accumulating knowledge about this interaction. It first emphasizes the unique spatial organization of the keratin intermediate filament cytoskeleton in different epithelial tissues to protect the organism against microbial insults. We then present examples of direct interaction between viral, bacterial, and parasitic proteins and the intermediate filament system and describe how this affects the microbe-host interaction by modulating the epithelial cytoskeleton, the progression of infection, and host response. These observations not only provide novel insights into the dynamics and function of intermediate filaments but also indicate future avenues to combat microbial infection. PMID:27355965

  12. Microbial Enzymes: Tools for Biotechnological Processes

    PubMed Central

    Adrio, Jose L.; Demain, Arnold L.

    2014-01-01

    Microbial enzymes are of great importance in the development of industrial bioprocesses. Current applications are focused on many different markets including pulp and paper, leather, detergents and textiles, pharmaceuticals, chemical, food and beverages, biofuels, animal feed and personal care, among others. Today there is a need for new, improved or/and more versatile enzymes in order to develop more novel, sustainable and economically competitive production processes. Microbial diversity and modern molecular techniques, such as metagenomics and genomics, are being used to discover new microbial enzymes whose catalytic properties can be improved/modified by different strategies based on rational, semi-rational and random directed evolution. Most industrial enzymes are recombinant forms produced in bacteria and fungi. PMID:24970208

  13. The information science of microbial ecology.

    PubMed

    Hahn, Aria S; Konwar, Kishori M; Louca, Stilianos; Hanson, Niels W; Hallam, Steven J

    2016-06-01

    A revolution is unfolding in microbial ecology where petabytes of 'multi-omics' data are produced using next generation sequencing and mass spectrometry platforms. This cornucopia of biological information has enormous potential to reveal the hidden metabolic powers of microbial communities in natural and engineered ecosystems. However, to realize this potential, the development of new technologies and interpretative frameworks grounded in ecological design principles are needed to overcome computational and analytical bottlenecks. Here we explore the relationship between microbial ecology and information science in the era of cloud-based computation. We consider microorganisms as individual information processing units implementing a distributed metabolic algorithm and describe developments in ecoinformatics and ubiquitous computing with the potential to eliminate bottlenecks and empower knowledge creation and translation.

  14. Microbial steroid transformations: current state and prospects.

    PubMed

    Donova, Marina V; Egorova, Olga V

    2012-06-01

    Studies of steroid modifications catalyzed by microbial whole cells represent a well-established research area in white biotechnology. Still, advances over the last decade in genetic and metabolic engineering, whole-cell biocatalysis in non-conventional media, and process monitoring raised research in this field to a new level. This review summarizes the data on microbial steroid conversion obtained since 2003. The key reactions of structural steroid functionalization by microorganisms are highlighted including sterol side-chain degradation, hydroxylation at various positions of the steroid core, and redox reactions. We also describe methods for enhancement of bioprocess productivity, selectivity of target reactions, and application of microbial transformations for production of valuable pharmaceutical ingredients and precursors. Challenges and prospects of whole-cell biocatalysis applications in steroid industry are discussed.

  15. Cancer-Promoting Effects of Microbial Dysbiosis

    PubMed Central

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

    2014-01-01

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

  16. Microbial precipitation of dolomite in methanogenic groundwater

    USGS Publications Warehouse

    Roberts, Jennifer A.; Bennett, Philip C.; Gonzalez, Luis A.; Macpherson, G.L.; Milliken, Kitty L.

    2004-01-01

    We report low-temperature microbial precipitation of dolomite in dilute natural waters from both field and laboratory experiments. In a freshwater aquifer, microorganisms colonize basalt and nucleate nonstoichiometric dolomite on cell walls. In the laboratory, ordered dolomite formed at near-equilibrium conditions from groundwater with molar Mg:Ca ratios of <1; dolomite was absent in sterile experiments. Geochemical and microbiological data suggest that methanogens are the dominant metabolic guild in this system and are integral to dolomite precipitation. We hypothesize that the attached microbial consortium reacts with the basalt surface, releasing Mg and Ca into solution, which drives dolomite precipitation via nucleation on the cell wall. These findings provide insight into the long-standing dolomite problem and suggest a fundamental role for microbial processes in the formation of dolomite across a wide range of environmental conditions.

  17. Specificity of marine microbial surface interactions.

    PubMed Central

    Imam, S H; Bard, R F; Tosteson, T R

    1984-01-01

    The macromolecular surface components involved in intraspecific cell surface interactions of the green microalga Chlorella vulgaris and closely associated bacteria were investigated. The specific surface attachment between this alga and its associated bacteria is mediated by lectin-like macromolecules associated with the surfaces of these cells. The binding activity of these surface polymers was inhibited by specific simple sugars; this suggests the involvement of specific receptor-ligand binding sites on the interactive surfaces. Epifluorescent microscopic evaluation of bacteria-alga interactions in the presence and absence of the macromolecules that mediate these interactions showed that the glycoproteins active in these processes were specific to the microbial sources from which they were obtained. The demonstration and definition of the specificity of these interactions in mixed microbial populations may play an important role in our understanding of the dynamics of marine microbial populations in the sea. PMID:6508293

  18. Microbial Ecology: Where are we now?

    PubMed Central

    2016-01-01

    Conventional microbiological methods have been readily taken over by newer molecular techniques due to the ease of use, reproducibility, sensitivity and speed of working with nucleic acids. These tools allow high throughput analysis of complex and diverse microbial communities, such as those in soil, freshwater, saltwater, or the microbiota living in collaboration with a host organism (plant, mouse, human, etc). For instance, these methods have been robustly used for characterizing the plant (rhizosphere), animal and human microbiome specifically the complex intestinal microbiota. The human body has been referred to as the Superorganism since microbial genes are more numerous than the number of human genes and are essential to the health of the host. In this review we provide an overview of the Next Generation tools currently available to study microbial ecology, along with their limitations and advantages. PMID:27975077

  19. Universal microbial diagnostics using random DNA probes

    PubMed Central

    Aghazadeh, Amirali; Lin, Adam Y.; Sheikh, Mona A.; Chen, Allen L.; Atkins, Lisa M.; Johnson, Coreen L.; Petrosino, Joseph F.; Drezek, Rebekah A.; Baraniuk, Richard G.

    2016-01-01

    Early identification of pathogens is essential for limiting development of therapy-resistant pathogens and mitigating infectious disease outbreaks. Most bacterial detection schemes use target-specific probes to differentiate pathogen species, creating time and cost inefficiencies in identifying newly discovered organisms. We present a novel universal microbial diagnostics (UMD) platform to screen for microbial organisms in an infectious sample, using a small number of random DNA probes that are agnostic to the target DNA sequences. Our platform leverages the theory of sparse signal recovery (compressive sensing) to identify the composition of a microbial sample that potentially contains novel or mutant species. We validated the UMD platform in vitro using five random probes to recover 11 pathogenic bacteria. We further demonstrated in silico that UMD can be generalized to screen for common human pathogens in different taxonomy levels. UMD’s unorthodox sensing approach opens the door to more efficient and universal molecular diagnostics. PMID:27704040

  20. Microbial survival in deep space environment.

    NASA Technical Reports Server (NTRS)

    Silverman, G. J.

    1971-01-01

    Review of the knowledge available on the extent to which microorganisms (mainly microbial spores, vegetative cells, and fungi) are capable of surviving the environment of deep space, based on recent simulation experiments of deep space. A description of the experimental procedures used is followed by a discussion of deep space ecology, the behavior of microorganisms in ultrahigh vacuum, and factors influencing microbial survival. It is concluded that, so far, simulation experiments have proved far less lethal to microorganisms than to other forms of life. There are, however, wide gaps in the knowledge available, and no accurate predictions can as yet be made on the degree of lethality that might be incurred by a microbial population on a given mission. Therefore, sterilization of spacecraft surfaces is deemed necessary if induced panspermia (i.e., interplanetary life propagation) is to be avoided.

  1. Microbial fuel cells for biosensor applications.

    PubMed

    Yang, Huijia; Zhou, Minghua; Liu, Mengmeng; Yang, Weilu; Gu, Tingyue

    2015-12-01

    Microbial fuel cells (MFCs) face major hurdles for real-world applications as power generators with the exception of powering small sensor devices. Despite tremendous improvements made in the last two decades, MFCs are still too expensive to build and operate and their power output is still too small. In view of this, in recently years, intensive researches have been carried out to expand the applications into other areas such as acid and alkali production, bioremediation of aquatic sediments, desalination and biosensors. Unlike power applications, MFC sensors have the immediate prospect to be practical. This review covers the latest developments in various proposed biosensor applications using MFCs including monitoring microbial activity, testing biochemical oxygen demand, detection of toxicants and detection of microbial biofilms that cause biocorrosion.

  2. Microfluidics Expanding the Frontiers of Microbial Ecology

    PubMed Central

    Rusconi, Roberto; Garren, Melissa; Stocker, Roman

    2014-01-01

    The ability afforded by microfluidics to observe the behaviors of microbes in highly controlled and confined microenvironments, across scales from a single cell to mixed communities, has significantly contributed to expand the frontiers of microbial ecology over the last decade. Spatially and temporally varying distributions of organisms and chemical cues that mimic natural microbial habitats can now be established by exploiting physics at the micrometer scale and by incorporating structures with specific geometries and materials. Here we review applications of microfluidics that have resulted in highly insightful discoveries on fundamental aspects of microbial life, ranging from growth and sensing to cell-cell interactions and population dynamics. We anticipate that this flexible, multidisciplinary technology will continue to facilitate discoveries regarding the ecology of microorganisms and help uncover strategies to control phenomena such as biofilm formation and antibiotic resistance. PMID:24773019

  3. Microbial Life Under Extreme Energy Limitation

    NASA Technical Reports Server (NTRS)

    Hoehler, Tori M.; Jorgensen, Bo Barker

    2013-01-01

    A great number of the bacteria and archaea on Earth are found in subsurface environments in a physiological state that is poorly represented or explained by laboratory cultures. Microbial cells in these very stable and oligotrophic settings catabolize 104- to 106-fold more slowly than model organisms in nutrient-rich cultures, turn over biomass on timescales of centuries to millennia rather than hours to days, and subsist with energy fluxes that are 1,000-fold lower than the typical culture-based estimates of maintenance requirements. To reconcile this disparate state of being with our knowledge of microbial physiology will require a revised understanding of microbial energy requirements, including identifying the factors that comprise true basal maintenance and the adaptations that might serve to minimize these factors.

  4. Microbial ecology of terrestrial Antarctica: Are microbial systems at risk from human activities?

    SciTech Connect

    White, G.J.

    1996-08-01

    Many of the ecological systems found in continental Antarctica are comprised entirely of microbial species. Concerns have arisen that these microbial systems might be at risk either directly through the actions of humans or indirectly through increased competition from introduced species. Although protection of native biota is covered by the Protocol on Environmental Protection to the Antarctic Treaty, strict measures for preventing the introduction on non-native species or for protecting microbial habitats may be impractical. This report summarizes the research conducted to date on microbial ecosystems in continental Antarctica and discusses the need for protecting these ecosystems. The focus is on communities inhabiting soil and rock surfaces in non-coastal areas of continental Antarctica. Although current polices regarding waste management and other operations in Antarctic research stations serve to reduce the introduction on non- native microbial species, importation cannot be eliminated entirely. Increased awareness of microbial habitats by field personnel and protection of certain unique habitats from physical destruction by humans may be necessary. At present, small-scale impacts from human activities are occurring in certain areas both in terms of introduced species and destruction of habitat. On a large scale, however, it is questionable whether the introduction of non-native microbial species to terrestrial Antarctica merits concern.

  5. MBGD update 2013: the microbial genome database for exploring the diversity of microbial world

    PubMed Central

    Uchiyama, Ikuo; Mihara, Motohiro; Nishide, Hiroyo; Chiba, Hirokazu

    2013-01-01

    The microbial genome database for comparative analysis (MBGD, available at http://mbgd.genome.ad.jp/) is a platform for microbial genome comparison based on orthology analysis. As its unique feature, MBGD allows users to conduct orthology analysis among any specified set of organisms; this flexibility allows MBGD to adapt to a variety of microbial genomic study. Reflecting the huge diversity of microbial world, the number of microbial genome projects now becomes several thousands. To efficiently explore the diversity of the entire microbial genomic data, MBGD now provides summary pages for pre-calculated ortholog tables among various taxonomic groups. For some closely related taxa, MBGD also provides the conserved synteny information (core genome alignment) pre-calculated using the CoreAligner program. In addition, efficient incremental updating procedure can create extended ortholog table by adding additional genomes to the default ortholog table generated from the representative set of genomes. Combining with the functionalities of the dynamic orthology calculation of any specified set of organisms, MBGD is an efficient and flexible tool for exploring the microbial genome diversity. PMID:23118485

  6. Cave speleothems as repositories of microbial biosignatures

    NASA Astrophysics Data System (ADS)

    Miller, Ana Z.; Jurado, Valme; Pereira, Manuel F. C.; Fernández, Octavio; Calaforra, José M.; Dionísio, Amélia; Saiz-Jimenez, Cesareo

    2015-04-01

    The need to better understand the biodiversity, origins of life on Earth and on other planets, and the wide applications of the microbe-mineral interactions have led to a rapid expansion of interest in subsurface environments. Recently reported results indicated signs of an early wet Mars and rather recent volcanic activity which suggest that Mars's subsurface can house organic molecules or traces of microbial life, making the search for microbial life on Earth's subsurface even more compelling. Caves on Earth are windows into the subsurface that harbor a wide variety of mineral-utilizing microorganisms, which may contribute to the formation of biominerals and unusual microstructures recognized as biosignatures. These environments contain a wide variety of redox interfaces and stable physicochemical conditions, which enhance secondary mineral precipitation and microbial growth under limited organic nutrient inputs. Enigmatic microorganisms and unusual mineral features have been found associated with secondary mineral deposits or speleothems in limestone caves and lava tubes. In this study, Field Emission Scanning Electron Microscopy (FESEM) and Energy Dispersive X-ray spectroscopy (EDS) analyses were conducted on cave speleothem samples to assess microbe-mineral interactions, evaluate biogenicity, as well as to describe unusual mineral formations and microbial features. Microbial mats, extracellular polymeric substances, tubular empty sheaths, mineralized cells, filamentous fabrics, as well as "cell-sized" etch pits or microborings produced by bacterial cells were observed on minerals. These features evidence microbe-mineral interactions and may represent mineralogical signatures of life. We can thus consider that caves on Earth are plausible repositories of terrestrial biosignatures where we can look for microbial signatures. Acknowledgments: AZM acknowledges the support from the Marie Curie Intra-European Fellowship within the 7th European Community Framework

  7. Microbial communities associated with house dust.

    PubMed

    Rintala, Helena; Pitkäranta, Miia; Täubel, Martin

    2012-01-01

    House dust is a complex mixture of inorganic and organic material with microbes in abundance. Few microbial species are actually able to grow and proliferate in dust and only if enough moisture is provided. Hence, most of the microbial content originates from sources other than the dust itself. The most important sources of microbes in house dust are outdoor air and other outdoor material tracked into the buildings, occupants of the buildings including pets and microbial growth on moist construction materials. Based on numerous cultivation studies, Penicillium, Aspergillus, Cladosporium, and about 20 other fungal genera are the most commonly isolated genera from house dust. The cultivable bacterial flora is dominated by Gram-positive genera, such as Staplylococcus, Corynebacterium, and Lactococcus. Culture-independent studies have shown that both the fungal and the bacterial flora are far more diverse, with estimates of up to 500-1000 different species being present in house dust. Concentrations of microbes in house dust vary from nondetectable to 10(9) cells g(-1) dust, depending on the dust type, detection method, type of the indoor environment and season, among other factors. Microbial assemblages in different house dust types usually share the same core species; however, alterations in the composition are caused by differing sources of microbes for different dust types. For example, mattress dust is dominated by species originating from the user of the mattress, whereas floor dust reflects rather outdoor sources. Farming homes contain higher microbial load than urban homes and according to a recent study, temperate climate zones show higher dust microbial diversity than tropical zones.

  8. Systems Biology of Microbial Exopolysaccharides Production

    PubMed Central

    Ates, Ozlem

    2015-01-01

    Exopolysaccharides (EPSs) produced by diverse group of microbial systems are rapidly emerging as new and industrially important biomaterials. Due to their unique and complex chemical structures and many interesting physicochemical and rheological properties with novel functionality, the microbial EPSs find wide range of commercial applications in various fields of the economy such as food, feed, packaging, chemical, textile, cosmetics and pharmaceutical industry, agriculture, and medicine. EPSs are mainly associated with high-value applications, and they have received considerable research attention over recent decades with their biocompatibility, biodegradability, and both environmental and human compatibility. However, only a few microbial EPSs have achieved to be used commercially due to their high production costs. The emerging need to overcome economic hurdles and the increasing significance of microbial EPSs in industrial and medical biotechnology call for the elucidation of the interrelations between metabolic pathways and EPS biosynthesis mechanism in order to control and hence enhance its microbial productivity. Moreover, a better understanding of biosynthesis mechanism is a significant issue for improvement of product quality and properties and also for the design of novel strains. Therefore, a systems-based approach constitutes an important step toward understanding the interplay between metabolism and EPS biosynthesis and further enhances its metabolic performance for industrial application. In this review, primarily the microbial EPSs, their biosynthesis mechanism, and important factors for their production will be discussed. After this brief introduction, recent literature on the application of omics technologies and systems biology tools for the improvement of production yields will be critically evaluated. Special focus will be given to EPSs with high market value such as xanthan, levan, pullulan, and dextran. PMID:26734603

  9. Microbial limitation in a changing world: A stoichiometric approach for predicting microbial resource limitation and fluxes

    NASA Astrophysics Data System (ADS)

    Midgley, M.; Phillips, R.

    2014-12-01

    Microbes mediate fluxes of carbon (C), nitrogen (N), and phosphorus (P) in soils depending on ratios of available C, N, and P relative to microbial demand. Hence, characterizing microbial C and nutrient limitation in soils is critical for predicting how ecosystems will respond to human alterations of climate and nutrient availability. Here, we take a stoichiometric approach to assessing microbial C, N, and P limitation by using threshold element ratios (TERs). TERs enable shifting resource limitation to be assessed by matching C, N and P ratios from microbial biomass, extracellular enzyme activities, and soil nutrient concentrations. We assessed microbial nutrient limitation in temperate forests dominated by trees that associate with one of two mycorrhizal symbionts: arbsucular mycorrhizal (AM) or ectomycorrhizal (ECM) fungi. We found that both ECM and AM microbial communities were co-limited by C and N, supporting conventional wisdom that microbes are C-limited and temperate forests are N-limited. However, AM microbial communities were relatively more C-limited than ECM communities (P=0.001). In response to chronic field N fertilization, both AM and ECM communities became relatively more P-limited (P=0.011), but they remained N- and C-limited overall. Thus, realistic levels of N deposition may not dampen microbial N limitation. Reflecting differences in relative limitation, N mineralization rates were higher in AM soils than in ECM soils (P=0.004) while C mineralization rates were higher in ECM soils than in AM soils (P=0.023). There were no significant differences in P flux between AM and ECM soils or detectable mineralization responses to N addition, indicating that mineralization rates are closely tied to C and nutrient limitation. Overall, we found that 1) microbial resource limitation can be detected without resource addition; and 2) TERs and ratios of labile resources are viable tools for predicting mineralization responses to resource additions.

  10. Microbial biofilms in intertidal systems: an overview

    NASA Astrophysics Data System (ADS)

    Decho, Alan W.

    2000-07-01

    Intertidal marine systems are highly dynamic systems which are characterized by periodic fluctuations in environmental parameters. Microbial processes play critical roles in the remineralization of nutrients and primary production in intertidal systems. Many of the geochemical and biological processes which are mediated by microorganisms occur within microenvironments which can be measured over micrometer spatial scales. These processes are localized by cells within a matrix of extracellular polymeric secretions (EPS), collectively called a "microbial biofilm". Recent examinations of intertidal systems by a range of investigators using new approaches show an abundance of biofilm communities. The purpose of this overview is to examine recent information concerning the roles of microbial biofilms in intertidal systems. The microbial biofilm is a common adaptation of natural bacteria and other microorganisms. In the fluctuating environments of intertidal systems, biofilms form protective microenvironments and may structure a range of microbial processes. The EPS matrix of biofilm forms sticky coatings on individual sediment particles and detrital surfaces, which act as a stabilizing anchor to buffer cells and their extracellular processes during the frequent physical stresses (e.g., changes in salinity and temperature, UV irradiation, dessication). EPS is an operational definition designed to encompass a range of large microbially-secreted molecules having widely varying physical and chemical properties, and a range of biological roles. Examinations of EPS using Raman and Fourier-transform infared spectroscopy, and atomic-force microscopy suggest that some EPS gels possess physical and chemical properties which may hasten the development of sharp geochemical gradients, and contribute a protective effect to cells. Biofilm polymers act as a sorptive sponge which binds and concentrates organic molecules and ions close to cells. Concurrently, the EPS appear to localize

  11. Microbial production of energy sources from biomass

    NASA Astrophysics Data System (ADS)

    Righelato, R. C.

    1980-02-01

    The biochemical options available for the microbial production of energy sources from biomass is reviewed and some of the technology available for microbial conversion is discussed with particular reference to present limitations and how they may be overcome. Attention is given to the chemical process of anaerobic fermentation emphasizing the chemical reaction of glucose into pyruvic acid. The capital costs and energy consumption of ethanol and methane and their production are discussed. It is concluded that anaerobic fermentation of carbohydrates and digestion of biomass-containing effluents can be used as methods for achieving greater energy availability.

  12. The Microbial Opsin Family of Optogenetic Tools

    SciTech Connect

    Zhang, Feng; Vierock, Johannes; Yizhar, Ofer; Fenno, Lief E.; Tsunoda, Satoshi; Kianianmomeni, Arash; Prigge, Matthias; Berndt, Andre; Cushman, John C.; Polle, Juergen E.; Magnuson, Jon K.; Hegemann, Peter; Deisseroth, Karl

    2011-12-23

    The capture and utilization of light is an exquisitely evolved process. The single-component microbial opsins, although more limited than multicomponent cascades in processing, display unparalleled compactness and speed. Recent advances in understanding microbial opsins have been driven by molecular engineering for optogenetics and by comparative genomics. Here we provide a Primer on these light-activated ion channels and pumps, describe a group of opsins bridging prior categories, and explore the convergence of molecular engineering and genomic discovery for the utilization and understanding of these remarkable molecular machines.

  13. [Progress in microbial production of succinic acid].

    PubMed

    Liu, Rongming; Liang, Liya; Wu, Mingke; Jiang, Min

    2013-10-01

    Succinic acid is one of the key intermediates in the tricarboxylic acid cycle (TCA)and has huge potentials in biopolymer, food, medicine applications. This article reviews recent research progress in the production of succinic acid by microbial fermentation, including discovery and screening of the succinic-acid-producing microbes, the progress of genetic engineering strategy and metabolic engineering technology for construction of succinic acid-producing strains, and fermentation process control and optimization. Finally, we discussed the limitation of current progress and proposed the future research needs for microbial production of succinic acid.

  14. 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

  15. MICROBIAL DEGRADATION OF SEVEN AMIDES BY SUSPENDED BACTERIAL POPULATIONS

    EPA Science Inventory

    Microbial transformation rate constants were determined for seven amides in natural pond water. A second-order mathematical rate expression served as the model for describing the microbial transformation. Also investigated was the relationship between the infrared spectra and the...

  16. Functional Microbial Diversity Explains Groundwater Chemistry in a Pristine Aquifer

    EPA Science Inventory

    Microbial communities inhabiting anoxic aquifers catalyze critical biogeochemical reactions in the subsurface, yet little is known about how their community structure correlates with groundwater chemistry. In this study, we described the composition of microbial communities in th...

  17. GEOELECTRICAL EVIDENCE OF MICROBIAL DEGRADATION OF DIESEL CONTAMINATED SEDIMENTS

    EPA Science Inventory

    The alteration of physical properties by microbial activity in petroleum contaminated sediments was investigated using geophysical techniques in laboratory column experiments. Microbial population growth was determined by the Most Probable Number technique (MPN), community dynami...

  18. Microbial Alteration of Maskelynite: Implications for ALH 84001

    NASA Technical Reports Server (NTRS)

    VanCleave, K. A.; Robbins, L. L.; Bell, M. S.

    2000-01-01

    To assess the origin of Fe and Mg-enriched carbonates associated with maskelynite in ALH 84001, we are conducting experiments involving the microbial alteration of feldspathic glass and any microbially-induced precipitation which results during this process.

  19. Microbial control of arthropod pests of orchards in temperate climates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Temperate orchards systems have several environmental features that make them conducive to microbial control strategies including adequate soil moisture, shading (protection from harmful UV) and stability. This chapter reviews and analyzes microbial control efforts in temperate orchards, including p...

  20. [Advances in microbial solar cells--A review].

    PubMed

    Guo, Xiaoyun; Yu, Changping; Zheng, Tianling

    2015-08-04

    The energy crisis has become one of the major problems hindering the development of the world. The emergence of microbial fuel cells provides a new solution to the energy crisis. Microbial solar cells, integrating photosynthetic organisms such as plants and microalgae into microbial fuel cells, can convert solar energy into electrical energy. Microbial solar cell has steady electric energy, and broad application prospects in wastewater treatment, biodiesel processing and intermediate metabolites production. Here we reviewed recent progress of microbial solar cells from the perspective of the role of photosynthetic organisms in microbial fuel cells, based on a vast amount of literature, and discussed their advantages and deficiency. At last, brief analysis of the facing problems and research needs of microbial fuel cells are undertaken. This work was expected to be beneficial for the application of the microbial solar cells technology.

  1. Environmental Microbial Community Proteomics: Status, Challenges and Perspectives

    PubMed Central

    Wang, Da-Zhi; Kong, Ling-Fen; Li, Yuan-Yuan; Xie, Zhang-Xian

    2016-01-01

    Microbial community proteomics, also termed metaproteomics, is an emerging field within the area of microbiology, which studies the entire protein complement recovered directly from a complex environmental microbial community at a given point in time. Although it is still in its infancy, microbial community proteomics has shown its powerful potential in exploring microbial diversity, metabolic potential, ecological function and microbe-environment interactions. In this paper, we review recent advances achieved in microbial community proteomics conducted in diverse environments, such as marine and freshwater, sediment and soil, activated sludge, acid mine drainage biofilms and symbiotic communities. The challenges facing microbial community proteomics are also discussed, and we believe that microbial community proteomics will greatly enhance our understanding of the microbial world and its interactions with the environment. PMID:27527164

  2. 7 CFR 3201.105 - Microbial cleaning products.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Microbial cleaning products. 3201.105 Section 3201... PROCUREMENT Designated Items § 3201.105 Microbial cleaning products. (a) Definition. (1) Cleaning agents that... include organisms that digest protein, starch, fat, and cellulose. (2) Microbial cleaning products...

  3. 21 CFR 866.2560 - Microbial growth monitor.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Microbial growth monitor. 866.2560 Section 866...) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Microbiology Devices § 866.2560 Microbial growth monitor. (a) Identification. A microbial growth monitor is a device intended for medical purposes...

  4. Microbial community structure elucidates performance of Glyceria maxima plant microbial fuel cell.

    PubMed

    Timmers, Ruud A; Rothballer, Michael; Strik, David P B T B; Engel, Marion; Schulz, Stephan; Schloter, Michael; Hartmann, Anton; Hamelers, Bert; Buisman, Cees

    2012-04-01

    The plant microbial fuel cell (PMFC) is a technology in which living plant roots provide electron donor, via rhizodeposition, to a mixed microbial community to generate electricity in a microbial fuel cell. Analysis and localisation of the microbial community is necessary for gaining insight into the competition for electron donor in a PMFC. This paper characterises the anode-rhizosphere bacterial community of a Glyceria maxima (reed mannagrass) PMFC. Electrochemically active bacteria (EAB) were located on the root surfaces, but they were more abundant colonising the graphite granular electrode. Anaerobic cellulolytic bacteria dominated the area where most of the EAB were found, indicating that the current was probably generated via the hydrolysis of cellulose. Due to the presence of oxygen and nitrate, short-chain fatty acid-utilising denitrifiers were the major competitors for the electron donor. Acetate-utilising methanogens played a minor role in the competition for electron donor, probably due to the availability of graphite granules as electron acceptors.

  5. 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

  6. Analysis of oxygen reduction and microbial community of air-diffusion biocathode in microbial fuel cells.

    PubMed

    Wang, Zejie; Zheng, Yue; Xiao, Yong; Wu, Song; Wu, Yicheng; Yang, Zhaohui; Zhao, Feng

    2013-09-01

    Microbes play irreplaceable role in oxygen reduction reaction of biocathode in microbial fuel cells (MFCs). In this study, air-diffusion biocathode MFCs were set up for accelerating oxygen reduction and microbial community analysis. Linear sweep voltammetry and Tafel curve confirmed the function of cathode biofilm to catalyze oxygen reduction. Microbial community analysis revealed higher diversity and richness of community in plankton than in biofilm. Proteobacteria was the shared predominant phylum in both biofilm and plankton (39.9% and 49.8%) followed by Planctomycetes (29.9%) and Bacteroidetes (13.3%) in biofilm, while Bacteroidetes (28.2%) in plankton. Minor fraction (534, 16.4%) of the total operational taxonomic units (3252) was overlapped demonstrating the disproportionation of bacterial distribution in biofilm and plankton. Pseudomonadales, Rhizobiales and Sphingobacteriales were exoelectrogenic orders in the present study. The research obtained deep insight of microbial community and provided more comprehensive information on uncultured rare bacteria.

  7. Impact of UV disinfection on microbially available phosphorus, organic carbon, and microbial growth in drinking water.

    PubMed

    Lehtola, Markku J; Miettinen, Ilkka T; Vartiainen, Terttu; Rantakokko, Panu; Hirvonen, Arja; Martikainen, Pertti J

    2003-03-01

    UV irradiation at a wavelength of 253.7 nm (UV(254)) is commonly used for drinking water disinfection. UV radiation is known to convert organically combined phosphorus to orthophosphate and to degrade natural organic matter. We studied if UV disinfection increases the amount of microbially available forms of organic carbon and phosphorus in drinking waters with different characteristics, and if these changes in water chemical quality could enhance the microbial growth in drinking water. The UV(254) dose (15-50 mWs/cm(2)) used in waterworks reduced the concentration of assimilable organic carbon and the sum of the molecular size fractions. The release of microbially available phosphorus needed higher doses (204 mWs/cm(2)) of UV(254) radiation. Of bacteria in drinking water, 90% were inactivated with UV(254)-irradiation doses below 50 mWs/cm(2). A high dose (501 mWs/cm(2)) of UV(254) radiation inhibited the microbial growth in water.

  8. 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.

  9. Microbial Diversity of Impact-Generated Habitats

    NASA Astrophysics Data System (ADS)

    Pontefract, Alexandra; Osinski, Gordon R.; Cockell, Charles S.; Southam, Gordon; McCausland, Phil J. A.; Umoh, Joseph; Holdsworth, David W.

    2016-10-01

    Impact-generated lithologies have recently been identified as viable and important microbial habitats, especially within cold and arid regions such as the polar deserts on Earth. These unique habitats provide protection from environmental stressors, such as freeze-thaw events, desiccation, and UV radiation, and act to trap aerially deposited detritus within the fissures and pore spaces, providing necessary nutrients for endoliths. This study provides the first culture-independent analysis of the microbial community structure within impact-generated lithologies in a Mars analog environment, involving the analysis of 44,534 16S rRNA sequences from an assemblage of 21 rock samples that comprises three shock metamorphism categories. We find that species diversity increases (H = 2.4-4.6) with exposure to higher shock pressures, which leads to the development of three distinct populations. In each population, Actinobacteria were the most abundant (41%, 65%, and 59%), and the dominant phototrophic taxa came from the Chloroflexi. Calculated porosity (a function of shock metamorphism) for these samples correlates (R2 = 0.62) with inverse Simpson indices, accounting for overlap in populations in the higher shock levels. The results of our study show that microbial diversity is tied to the amount of porosity in the target substrate (as a function of shock metamorphism), resulting in the formation of distinct microbial populations.

  10. Microbial production of amino acids in Japan.

    PubMed

    Kumagai, H

    2000-01-01

    The microbial biotechnology of amino acids production which was developed and industrialized in Japan have been summarized. The amino acids include L-glutamic acid, L-lysine, L-threonine, L-aspartic acid, L-alanine, L-cysteine, L-dihydroxyphenylalanine, D-p-hydroxyphenyl-glycine, and hydroxy-L-proline.

  11. Uncovering the Horseshoe Effect in Microbial Analyses

    PubMed Central

    Morton, James T.; Toran, Liam; Edlund, Anna; Metcalf, Jessica L.; Lauber, Christian

    2017-01-01

    ABSTRACT The horseshoe effect is a phenomenon that has long intrigued ecologists. The effect was commonly thought to be an artifact of dimensionality reduction, and multiple techniques were developed to unravel this phenomenon and simplify interpretation. Here, we provide evidence that horseshoes arise as a consequence of distance metrics that saturate—a familiar concept in other fields but new to microbial ecology. This saturation property loses information about community dissimilarity, simply because it cannot discriminate between samples that do not share any common features. The phenomenon illuminates niche differentiation in microbial communities and indicates species turnover along environmental gradients. Here we propose a rationale for the observed horseshoe effect from multiple dimensionality reduction techniques applied to simulations, soil samples, and samples from postmortem mice. An in-depth understanding of this phenomenon allows targeting of niche differentiation patterns from high-level ordination plots, which can guide conventional statistical tools to pinpoint microbial niches along environmental gradients. IMPORTANCE The horseshoe effect is often considered an artifact of dimensionality reduction. We show that this is not true in the case for microbiome data and that, in fact, horseshoes can help analysts discover microbial niches across environments. PMID:28251186

  12. Nutrient addition dramatically accelerates microbial community succession.

    PubMed

    Knelman, Joseph E; Schmidt, Steven K; Lynch, Ryan C; Darcy, John L; Castle, Sarah C; Cleveland, Cory C; Nemergut, Diana R

    2014-01-01

    The ecological mechanisms driving community succession are widely debated, particularly for microorganisms. While successional soil microbial communities are known to undergo predictable changes in structure concomitant with shifts in a variety of edaphic properties, the causal mechanisms underlying these patterns are poorly understood. Thus, to specifically isolate how nutrients--important drivers of plant succession--affect soil microbial succession, we established a full factorial nitrogen (N) and phosphorus (P) fertilization plot experiment in recently deglaciated (∼3 years since exposure), unvegetated soils of the Puca Glacier forefield in Southeastern Peru. We evaluated soil properties and examined bacterial community composition in plots before and one year after fertilization. Fertilized soils were then compared to samples from three reference successional transects representing advancing stages of soil development ranging from 5 years to 85 years since exposure. We found that a single application of +NP fertilizer caused the soil bacterial community structure of the three-year old soils to most resemble the 85-year old soils after one year. Despite differences in a variety of soil edaphic properties between fertilizer plots and late successional soils, bacterial community composition of +NP plots converged with late successional communities. Thus, our work suggests a mechanism for microbial succession whereby changes in resource availability drive shifts in community composition, supporting a role for nutrient colimitation in primary succession. These results suggest that nutrients alone, independent of other edaphic factors that change with succession, act as an important control over soil microbial community development, greatly accelerating the rate of succession.

  13. Syntrophic exchange in synthetic microbial communities

    PubMed Central

    Mee, Michael T.; Collins, James J.; Church, George M.; Wang, Harris H.

    2014-01-01

    Metabolic crossfeeding is an important process that can broadly shape microbial communities. However, little is known about specific crossfeeding principles that drive the formation and maintenance of individuals within a mixed population. Here, we devised a series of synthetic syntrophic communities to probe the complex interactions underlying metabolic exchange of amino acids. We experimentally analyzed multimember, multidimensional communities of Escherichia coli of increasing sophistication to assess the outcomes of synergistic crossfeeding. We find that biosynthetically costly amino acids including methionine, lysine, isoleucine, arginine, and aromatics, tend to promote stronger cooperative interactions than amino acids that are cheaper to produce. Furthermore, cells that share common intermediates along branching pathways yielded more synergistic growth, but exhibited many instances of both positive and negative epistasis when these interactions scaled to higher dimensions. In more complex communities, we find certain members exhibiting keystone species-like behavior that drastically impact the community dynamics. Based on comparative genomic analysis of >6,000 sequenced bacteria from diverse environments, we present evidence suggesting that amino acid biosynthesis has been broadly optimized to reduce individual metabolic burden in favor of enhanced crossfeeding to support synergistic growth across the biosphere. These results improve our basic understanding of microbial syntrophy while also highlighting the utility and limitations of current modeling approaches to describe the dynamic complexities underlying microbial ecosystems. This work sets the foundation for future endeavors to resolve key questions in microbial ecology and evolution, and presents a platform to develop better and more robust engineered synthetic communities for industrial biotechnology. PMID:24778240

  14. QUANTITATIVE RISK ASSESSMENT FOR MICROBIAL AGENTS

    EPA Science Inventory

    Compared to chemical risk assessment, the process for microbial agents and infectious disease is more complex because of host factors and the variety of settings in which disease transmission can occur. While the National Academy of Science has established a paradigm for performi...

  15. Arctic permafrost: Microbial lid on subsea methane

    NASA Astrophysics Data System (ADS)

    Thornton, Brett F.; Crill, Patrick

    2015-08-01

    Submarine permafrost thaw in the Arctic has been suggested as a trigger for the release of large quantities of methane to the water column, and subsequently the atmosphere -- with important implications for global warming. Now research shows that microbial oxidation of methane at the thaw front can effectively prevent its release.

  16. Microbial Control of Structural Insect Pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three major pest groups affecting urban structures, ants, termites, and peridomestic cockroaches, are potentially the most amenable for the development of microbial controls. It is not only because of their economic importance, but their biology and ecology make them more susceptible to control by e...

  17. Microbial colonization in orthodontic mini-implants.

    PubMed

    de Freitas, Amanda Osório Ayres; Alviano, Celuta Sales; Alviano, Daniela Sales; Siqueira, José Freitas; Nojima, Lincoln Issamu; Nojima, Matilde da Cunha Gonçalves

    2012-01-01

    Peri-implant inflammation contributes for loss of secondary stability of orthodontic mini-implants. The investigation of microbial colonization in this area would benefit its control, and consequently favor the long-term success of mini-implants. Therefore, the aim of this study was to determine the establishment and the evolution of microbial colonization process in orthodontic mini-implants for 3 months, since the time of their installation. One-hundred and fifty samples collected from 15 mini-implants were investigated from baseline up to 3 months. The biological material was obtained from peri-implant area using paper points. Nonspecific, Streptococcus spp, Lactobacillus casei and Candida spp colonizations were analyzed by cell growth methods. Porphyromonas gingivalis colonization was observed by 16S rDNA-directed polymerase chain reaction. Data from cell growth were submitted to the Wilcoxon sign rank test and results from molecular analysis were presented in a descriptive way. There was no significant difference in the microbial colonization among the examined time intervals, except for Streptococcus spp, between baseline and 24 h, which characterized the initial colonization in this time interval. Lactobacillus casei and Candida spp colonizations were insignificant. No Porphyromonas gingivalis was detected among the analyzed samples. The microbial colonization of mini-implants did not significantly change during the study. However, it should be monitored by orthodontists, since it is an important factor for mini-implants success.

  18. Interval scanning photomicrography of microbial cell populations.

    NASA Technical Reports Server (NTRS)

    Casida, L. E., Jr.

    1972-01-01

    A single reproducible area of the preparation in a fixed focal plane is photographically scanned at intervals during incubation. The procedure can be used for evaluating the aerobic or anaerobic growth of many microbial cells simultaneously within a population. In addition, the microscope is not restricted to the viewing of any one microculture preparation, since the slide cultures are incubated separately from the microscope.

  19. The Forminalized Rat: A Convenient Microbial Ecosystem.

    ERIC Educational Resources Information Center

    Lee, Adrian

    1984-01-01

    Presents a series of experiments built around the bacteria found in the intestinal tract of formalinized rats as a model for discussing microbial ecology. Describes methods of examination of intestinal content, student tasks, and discussion questions; also gives a challenge problem to solve.

  20. Screening criteria for microbial for processes

    SciTech Connect

    Bryant, R.S.

    1990-12-01

    The National Institute for Petroleum and Energy Research (NIPER) has maintained a microbial enhanced oil recovery (MEOR) field project data base since 1985. One of the major goals of this data base is to continue to document characteristics of reservoirs used for MEOR field projects and to assist the US Department of Energy by revising published screening criteria for MEOR processes. Since the last update of this data base in 1987, the number of MEOR field projects entered has increased from 39 to 65. Microbial EOR has been recognized as a potentially cost-effective method, particularly for stripper well production. Stripper wells are particularly in need of cost-effective EOR because independent operators produce about 40% of the total oil recovered, but cannot conduct needed EOR research. Microbial methods for improving oil recovery are potentially cost-effective and particularly well suited to be applied in today's economic climate. The lower price of crude oil as well as a more general acceptance of use of biotechnological processes has probably contributed to this increase. Although in some instances information was unavailable or not reported for each element of the data base, there exists adequate data to demonstrate both the viability and variety of options for using microbial technology for improved oil production. this report updates the data base and provides summary of several of the more important MEOR field experiments conducted during the 1970s and 1980s. 19 refs., 1 fig., 11 tabs.

  1. Modeling and applications in microbial food safety

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mathematical modeling is a scientific and systematic approach to study and describe the recurrent events or phenomena with successful application track for decades. When models are properly developed and validated, their applications may save costs and time. For the microbial food safety concerns, ...

  2. MICROBIAL SOURCE TRACKING: DIFFERENT USES AND APPROACHES

    EPA Science Inventory

    Microbial Source Tracking (MST) methods are used to determine the origin of fecal pollution impacting natural water systems. Several methods require the isolation of pure cultures in order to develop phenotypic or genotypic fingerprint libraries of both source and water bacterial...

  3. Using Omics to Study Microbial Water Quality

    EPA Science Inventory

    Water is one of the most important resources of all natural ecosystems. Not only is water important to life, but it is also a habitat for a large diversity of microbial forms, in many cases carrying critical geochemical functions. In other instances, water is implicated in outbre...

  4. Ohmic resistance affects microbial community and ...

    EPA Pesticide Factsheets

    Multi-anode microbial electrochemical cells (MXCs) are considered as one of the most promising configurations for scale-up of MXCs, but fundamental understanding of anode kinetics governing current density is limited in the MXCs. In this study we first assessed microbial community and electrochemical kinetic parameters for biofilms on individual anodes in a multi-anode MXC to better comprehend anode fundamentals. Microbial community analysis using 16S rRNA illumine sequencing showed that Geobactor genus, one of the most kinetically efficient anode-respiring bacteria (ARB), was abundant (87%) only on the biofilm anode closest to a reference electrode in which current density was the highest among four anodes. In comparison, Geobacter populations were less than 11% for other three anodes more distant from the reference electrode, generating small current density. Half-saturation anode potential (EKA) was the lowest at -0.251 to -0.242 V (vs. standard hydrogen electrode) for the closest anode, while EKA was as high as -0.134 V for the farthest anode. Our study clearly proves that ohmic resistance changes anode potential which mainly causes different biofilm communities on individual anodes and consequently influences anode kinetics. This study explored the use of multiple anodes in microelectrochemical cells and the microbial community on these anodes, as a function of the efficiency in producing hydrogen peroxide.

  5. The Biogeography of Putative Microbial Antibiotic Production.

    PubMed

    Morlon, Hélène; O'Connor, Timothy K; Bryant, Jessica A; Charkoudian, Louise K; Docherty, Kathryn M; Jones, Evan; Kembel, Steven W; Green, Jessica L; Bohannan, Brendan J M

    2015-01-01

    Understanding patterns in the distribution and abundance of functional traits across a landscape is of fundamental importance to ecology. Mapping these distributions is particularly challenging for species-rich groups with sparse trait measurement coverage, such as flowering plants, insects, and microorganisms. Here, we use likelihood-based character reconstruction to infer and analyze the spatial distribution of unmeasured traits. We apply this framework to a microbial dataset comprised of 11,732 ketosynthase alpha gene sequences extracted from 144 soil samples from three continents to document the spatial distribution of putative microbial polyketide antibiotic production. Antibiotic production is a key competitive strategy for soil microbial survival and performance. Additionally, novel antibiotic discovery is highly relevant to human health, making natural antibiotic production by soil microorganisms a major target for bioprospecting. Our comparison of trait-based biogeographical patterns to patterns based on taxonomy and phylogeny is relevant to our basic understanding of microbial biogeography as well as the pressing need for new antibiotics.

  6. The Biogeography of Putative Microbial Antibiotic Production

    PubMed Central

    Bryant, Jessica A.; Charkoudian, Louise K.; Docherty, Kathryn M.; Jones, Evan; Kembel, Steven W.; Green, Jessica L.; Bohannan, Brendan J. M.

    2015-01-01

    Understanding patterns in the distribution and abundance of functional traits across a landscape is of fundamental importance to ecology. Mapping these distributions is particularly challenging for species-rich groups with sparse trait measurement coverage, such as flowering plants, insects, and microorganisms. Here, we use likelihood-based character reconstruction to infer and analyze the spatial distribution of unmeasured traits. We apply this framework to a microbial dataset comprised of 11,732 ketosynthase alpha gene sequences extracted from 144 soil samples from three continents to document the spatial distribution of putative microbial polyketide antibiotic production. Antibiotic production is a key competitive strategy for soil microbial survival and performance. Additionally, novel antibiotic discovery is highly relevant to human health, making natural antibiotic production by soil microorganisms a major target for bioprospecting. Our comparison of trait-based biogeographical patterns to patterns based on taxonomy and phylogeny is relevant to our basic understanding of microbial biogeography as well as the pressing need for new antibiotics. PMID:26102275

  7. Relevance of antarctic microbial ecosystems to exobiology

    NASA Technical Reports Server (NTRS)

    Mckay, Christopher P.

    1993-01-01

    Antarctic microbial ecosystems which provide biological and physical analogs that can be used in exobiology are studied. Since the access to extraterrestrial habitats is extremely difficult, terrestrial analogs represent the best opportunity for both formulation and preliminary testing of hypothesis about life. Antarctica, as one of few suitable environments on earth is considered to be a major locus of progress in exobiology.

  8. Anticorrosive Microbial Polysaccharides: Structure-Function Relationships

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water-soluble microbial polysaccharides are often implicated in biofilm formation and are believed to mediate cell-cell aggregation and adhesion to surfaces. Generally, biofilm formation is considered harmful or undesirable, as it leads to increased drag, plugging of pores, dimished heat transfer, ...

  9. 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.

  10. Microbial food safety - modeling and applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microbial food safety is a key issue for the food processing industry, and enhancing food safety is everyone’s responsibility from food producers to consumers. Financial losses to the economy due to foodborne illness are in the billions of dollars, annually. Foodborne illness can be caused by patho...

  11. Perspectives of microbial oils for biodiesel production.

    PubMed

    Li, Qiang; Du, Wei; Liu, Dehua

    2008-10-01

    Biodiesel has become more attractive recently because of its environmental benefits, and the fact that it is made from renewable resources. Generally speaking, biodiesel is prepared through transesterification of vegetable oils or animal fats with short chain alcohols. However, the lack of oil feedstocks limits the large-scale development of biodiesel to some extent. Recently, much attention has been paid to the development of microbial, oils and it has been found that many microorganisms, such as algae, yeast, bacteria, and fungi, have the ability to accumulate oils under some special cultivation conditions. Compared to other plant oils, microbial oils have many advantages, such as short life cycle, less labor required, less affection by venue, season and climate, and easier to scale up. With the rapid expansion of biodiesel, microbial oils might become one of potential oil feedstocks for biodiesel production in the future, though there are many works associated with microorganisms producing oils need to be carried out further. This review is covering the related research about different oleaginous microorganisms producing oils, and the prospects of such microbial oils used for biodiesel production are also discussed.

  12. Mass Spectrometry Imaging of Complex Microbial Communities

    PubMed Central

    2016-01-01

    Conspectus In the two decades since mass spectrometry imaging (MSI) was first applied to visualize the distribution of peptides across biological tissues and cells, the technique has become increasingly effective and reliable. MSI excels at providing complementary information to existing methods for molecular analysis—such as genomics, transcriptomics, and metabolomics—and stands apart from other chemical imaging modalities through its capability to generate information that is simultaneously multiplexed and chemically specific. Today a diverse family of MSI approaches are applied throughout the scientific community to study the distribution of proteins, peptides, and small-molecule metabolites across many biological models. The inherent strengths of MSI make the technique valuable for studying microbial systems. Many microbes reside in surface-attached multicellular and multispecies communities, such as biofilms and motile colonies, where they work together to harness surrounding nutrients, fend off hostile organisms, and shield one another from adverse environmental conditions. These processes, as well as many others essential for microbial survival, are mediated through the production and utilization of a diverse assortment of chemicals. Although bacterial cells are generally only a few microns in diameter, the ecologies they influence can encompass entire ecosystems, and the chemical changes that they bring about can occur over time scales ranging from milliseconds to decades. Because of their incredible complexity, our understanding of and influence over microbial systems requires detailed scientific evaluations that yield both chemical and spatial information. MSI is well-positioned to fulfill these requirements. With small adaptations to existing methods, the technique can be applied to study a wide variety of chemical interactions, including those that occur inside single-species microbial communities, between cohabitating microbes, and between microbes

  13. Kombucha tea fermentation: Microbial and biochemical dynamics.

    PubMed

    Chakravorty, Somnath; Bhattacharya, Semantee; Chatzinotas, Antonis; Chakraborty, Writachit; Bhattacharya, Debanjana; Gachhui, Ratan

    2016-03-02

    Kombucha tea, a non-alcoholic beverage, is acquiring significant interest due to its claimed beneficial properties. The microbial community of Kombucha tea consists of bacteria and yeast which thrive in two mutually non-exclusive compartments: the soup or the beverage and the biofilm floating on it. The microbial community and the biochemical properties of the beverage have so far mostly been described in separate studies. This, however, may prevent understanding the causal links between the microbial communities and the beneficial properties of Kombucha tea. Moreover, an extensive study into the microbial and biochemical dynamics has also been missing. In this study, we thus explored the structure and dynamics of the microbial community along with the biochemical properties of Kombucha tea at different time points up to 21 days of fermentation. We hypothesized that several biochemical properties will change during the course of fermentation along with the shifts in the yeast and bacterial communities. The yeast community of the biofilm did not show much variation over time and was dominated by Candida sp. (73.5-83%). The soup however, showed a significant shift in dominance from Candida sp. to Lachancea sp. on the 7th day of fermentation. This is the first report showing Candida as the most dominating yeast genus during Kombucha fermentation. Komagateibacter was identified as the single largest bacterial genus present in both the biofilm and the soup (~50%). The bacterial diversity was higher in the soup than in the biofilm with a peak on the seventh day of fermentation. The biochemical properties changed with the progression of the fermentation, i.e., beneficial properties of the beverage such as the radical scavenging ability increased significantly with a maximum increase at day 7. We further observed a significantly higher D-saccharic acid-1,4-lactone content and caffeine degradation property compared to previously described Kombucha tea fermentations. Our

  14. Microbial Threats to Health. Emerging Infections: Microbial Threats to Health in the United States.

    DTIC Science & Technology

    1992-10-01

    Cryptosporidiosis - a parasitic infection of the epithelial cells of the gastrointestinal . biliary, and respiratory tracts of man, as well as other... gastrointestinal tract (where the female lays eggs) MODE OF TRANSMISSION - penetration of skin or mucous membrane by infective larvae (usually from fecally...AD-A257 841 AD____ GRANT NO: DAMD17-90-Z-0047 TITLE: MICROBIAL THREATS TO HEALTH SUBTITLE: REmerging Infections - Microbial Threats to Health in the

  15. Phylogenetic & Physiological Profiling of Microbial Communities of Contaminated Soils/Sediments: Identifying Microbial consortia...

    SciTech Connect

    Terence L. Marsh

    2004-05-26

    The goals of this study were: (1) survey the microbial community in soil samples from a site contaminated with heavy metals using new rapid molecular techniques that are culture-independent; (2) identify phylogenetic signatures of microbial populations that correlate with metal ion contamination; and (3) cultivate these diagnostic strains using traditional as well as novel cultivation techniques in order to identify organisms that may be of value in site evaluation/management or bioremediation.

  16. Tackling inequalities in obesity: a protocol for a systematic review of the effectiveness of public health interventions at reducing socioeconomic inequalities in obesity amongst children

    PubMed Central

    2012-01-01

    , Sociological Abstracts and the NHS Economic Evaluation Database. Database searches will be supplemented with website and grey literature searches. No studies will be excluded on the basis of language, country of origin or publication date. Study inclusion, data extraction and quality appraisal will be conducted by two reviewers. Meta-analysis and narrative synthesis will be conducted. The main analysis will examine the effects of (1) individual, (2) community and (3) societal level public health interventions on socioeconomic inequalities in childhood obesity. Interventions will be characterised by their level of action and their approach to tackling inequalities. Contextual information on how such public health interventions are organised, implemented and delivered will also be examined. Discussion In this review, we consider public health strategies which reduce and prevent inequalities in the prevalence of childhood obesity, highlight any gaps in the evidence base and seek to establish how such public health interventions are organised, implemented and delivered. PROSPERO registration number: CRD42011001740 PMID:22587775

  17. Microbial inoculants and their impact on soil microbial communities: a review.

    PubMed

    Trabelsi, Darine; Mhamdi, Ridha

    2013-01-01

    The knowledge of the survival of inoculated fungal and bacterial strains in field and the effects of their release on the indigenous microbial communities has been of great interest since the practical use of selected natural or genetically modified microorganisms has been developed. Soil inoculation or seed bacterization may lead to changes in the structure of the indigenous microbial communities, which is important with regard to the safety of introduction of microbes into the environment. Many reports indicate that application of microbial inoculants can influence, at least temporarily, the resident microbial communities. However, the major concern remains regarding how the impact on taxonomic groups can be related to effects on functional capabilities of the soil microbial communities. These changes could be the result of direct effects resulting from trophic competitions and antagonistic/synergic interactions with the resident microbial populations, or indirect effects mediated by enhanced root growth and exudation. Combination of inoculants will not necessarily produce an additive or synergic effect, but rather a competitive process. The extent of the inoculation impact on the subsequent crops in relation to the buffering capacity of the plant-soil-biota is still not well documented and should be the focus of future research.

  18. Microbial communities involved in electricity generation from sulfide oxidation in a microbial fuel cell.

    PubMed

    Sun, Min; Tong, Zhong-Hua; Sheng, Guo-Ping; Chen, Yong-Zhen; Zhang, Feng; Mu, Zhe-Xuan; Wang, Hua-Lin; Zeng, Raymond J; Liu, Xian-Wei; Yu, Han-Qing; Wei, Li; Ma, Fang

    2010-10-15

    Simultaneous electricity generation and sulfide removal can be achieved in a microbial fuel cell (MFC). In electricity harvesting from sulfide oxidation in such an MFC, various microbial communities are involved. It is essential to elucidate the microbial communities and their roles in the sulfide conversion and electricity generation. In this work, an MFC was constructed to enrich a microbial consortium, which could harvest electricity from sulfide oxidation. Electrochemical analysis demonstrated that microbial catalysis was involved in electricity output in the sulfide-fed MFC. The anode-attached and planktonic communities could perform catalysis independently, and synergistic interactions occurred when the two communities worked together. A 16S rRNA clone library analysis was employed to characterize the microbial communities in the MFC. The anode-attached and planktonic communities shared similar richness and diversity, while the LIBSHUFF analysis revealed that the two community structures were significantly different. The exoelectrogenic, sulfur-oxidizing and sulfate-reducing bacteria were found in the MFC anodic chamber. The discovery of these bacteria was consistent with the community characteristics for electricity generation from sulfide oxidation. The exoelectrogenic bacteria were found both on the anode and in the solution. The sulfur-oxidizing bacteria were present in greater abundance on the anode than in the solution, while the sulfate-reducing bacteria preferably lived in the solution.

  19. Microbial Inoculants and Their Impact on Soil Microbial Communities: A Review

    PubMed Central

    2013-01-01

    The knowledge of the survival of inoculated fungal and bacterial strains in field and the effects of their release on the indigenous microbial communities has been of great interest since the practical use of selected natural or genetically modified microorganisms has been developed. Soil inoculation or seed bacterization may lead to changes in the structure of the indigenous microbial communities, which is important with regard to the safety of introduction of microbes into the environment. Many reports indicate that application of microbial inoculants can influence, at least temporarily, the resident microbial communities. However, the major concern remains regarding how the impact on taxonomic groups can be related to effects on functional capabilities of the soil microbial communities. These changes could be the result of direct effects resulting from trophic competitions and antagonistic/synergic interactions with the resident microbial populations, or indirect effects mediated by enhanced root growth and exudation. Combination of inoculants will not necessarily produce an additive or synergic effect, but rather a competitive process. The extent of the inoculation impact on the subsequent crops in relation to the buffering capacity of the plant-soil-biota is still not well documented and should be the focus of future research. PMID:23957006

  20. Influence of substrate and microbial interaction on efficiency of rumen microbial growth.

    PubMed

    Demeyer, D; Van Nevel, C

    1986-01-01

    Microbial N produced in the rumen and flowing to the duodenum (Ni) is related to the total amount of OM fermented or apparently digested in the rumen (OMf). This relationship, best expressed as microbial N yield (gNi/kgOMf), is affected mainly by the physical and chemical properties of feed carbohydrates and the amounts ingested. These factors influence yields at three levels of increasing complexity: Bacterial fermentation within one compartment following the continuous culture model. Fermentation pattern as such does not seem to affect yields. High fermentation rates are associated with lactate production, low methane production and transient polysaccharide synthesis. These effects induce acidification and lower yields, partly compensated by faster growth. Protozoal action, determined by the presence of sequestration spaces provided mainly by roughage diets. The presence of protozoa depresses microbial N yield but allows more complete fibre digestion. Compartmentation and differential passage. With roughage diets, optimal microbial N yield seems to require well developed microbial compartmentation, involving a large proportion of microbes in a large-particle pool with a slow turnover, balanced by a small proportion in liquid, small-particle pools with a fast turnover. Such a situation is associated with long roughage feeding. It is hypothesized that microbial N yields in the rumen may vary between two extremes which are associated with the feeding of long roughage on the one hand or with concentrate (starch) feeding on the other.