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Diverse Communities (diverse + community)
Selected AbstractsAutoinducers extracted from microbial mats reveal a surprising diversity of N -acylhomoserine lactones (AHLs) and abundance changes that may relate to diel pHENVIRONMENTAL MICROBIOLOGY, Issue 2 2009Alan W. Decho Summary Microbial mats are highly structured and diverse communities, and one of the earliest-known life assemblages. Mat bacteria interact within an environment marked by strong geochemical gradients and fluctuations. We examined natural mat systems for the presence of autoinducers involved in quorum sensing, a form of cell,cell communication. Our results revealed that a diverse array of N -acylhomoserine lactones (AHLs) including C4 - to C14 -AHLs, were identified from mat extracts using mass spectrometry (MS), with further confirmation by MS/MS-collision-induced dissociation (CID), and additions of external standards. Microelectrode measurements showed that mats exhibited diel pH fluctuations, ranging from alkaline (pH 9.4) during daytime (net photosynthesis) to acidic (pH 6.8) during darkness (net respiration/fermentation). Under laboratory conditions, AHLs having shorter acyl-chains were degraded within the time frame that daily alkaline pH (> 8.2) conditions exist in mats. Intensive sampling of mats after full day- or night-time incubations revealed that accumulations of extractable shorter-chain AHLs (e.g. C8 - and C10 -AHLs) were significantly (P < 0.001) diminished during daytime. Our study offers evidence that stabilities of AHLs under natural conditions may be influenced by the proximal extracellular environment. We further propose that the ancient periodicity of photosynthesis/respiration in mats may potentially drive a mechanism for diel differences in activities of certain autoinducers, and hence bacterial activities mediated through quorum sensing. [source] Host plant development, water level and water parameters shape Phragmites australis -associated oomycete communities and determine reed pathogen dynamics in a large lakeFEMS MICROBIOLOGY ECOLOGY, Issue 2 2009Anna Wielgoss Abstract In a 3-year-study, we analysed the population dynamics of the reed pathogen Pythium phragmitis and other reed-associated oomycetes colonizing fresh and dried reed leaves in the littoral zone of a large lake. Oomycete communities derived from internal transcribed spacer clone libraries were clearly differentiated according to substrate and seasonal influences. In fresh leaves, diverse communities consisting of P. phragmitis and other reed-associated pathogens were generally dominant. Pythium phragmitis populations peaked in spring with the emergence of young reed shoots, and in autumn after extreme flooding events. In summer it decreased with falling water levels, changing water chemistry and rising temperatures. Another Pythium species was also highly abundant in fresh leaves throughout the year and might represent a new, as-yet uncultured reed pathogen. In dried leaves, reed pathogens were rarely detected, whereas saprophytic species occurred abundantly during all seasons. Saprophyte communities were less diverse, less temperature sensitive and independent of reed development. In general, our results provide evidence for the occurrence of highly specialized sets of reed-associated oomycetes in a natural reed ecosystem. Quantitative analyses (clone abundances and quantitative real-time PCR) revealed that the reed pathogen P. phragmitis is particularly affected by changing water levels, water chemistry and the stage of reed development. [source] Nutrient dependent effects of consumer identity and diversity on freshwater ecosystem functionFRESHWATER BIOLOGY, Issue 1 2008ANDREW R. DZIALOWSKI Summary 1. Over the past decade, ecologists have tried to determine how changes in species composition and diversity affect ecosystem structure and function. Until recently, the majority of these studies have been conducted in terrestrial ecosystems and have not taken into account environmental variability. The purpose of this research was to determine how species identity and diversity in the freshwater zooplankton affected biomass of algae and zooplankton at two levels of nutrient enrichment. 2. Several species of cladocerans were grown alone and together in microcosms at both ambient and raised phosphorus concentrations to determine if the effects of consumer identity and diversity were nutrient dependent. 3. Total zooplankton biomass was greater, while algal biomass was lower, in mixed culture than in monoculture. The effects of zooplankton diversity on algal biomass, however, were only observed at raised phosphorus concentrations, suggesting that diversity effects were nutrient dependent. Specifically, diversity effects appeared to be related with biological mechanisms such as complementarity in resource use and/or facilitation. 4. More diverse communities of zooplankton appear to be better able to control algae than single species of zooplankton at high nutrient concentrations; therefore, zooplankton diversity may provide a buffer against eutrophication in freshwater ecosystems. [source] Species richness and susceptibility to heat and drought extremes in synthesized grassland ecosystems: compositional vs physiological effectsFUNCTIONAL ECOLOGY, Issue 6 2004L. VAN PEER Summary 1We investigated effects of declining plant species richness (S) on resistance to extremes in grassland communities. 2Synthesized model ecosystems of different S, grown outdoors in containers, were exposed to a stress peak combining heat and drought. The heat wave was induced experimentally by infrared irradiation in free air conditions. 3Before the heat wave, the more species-rich communities produced more biomass as a result of a large and positive complementarity effect that outweighed a small negative selection effect. 4Water use during the heat wave was likewise enhanced by S, which could not be attributed to dominance of ,water-wasting' species. Instead, water consumption at high S exceeded that expected from changes in community biomass and biomass composition. The observed enhancement of resource (water) acquisition under stress with increasing S therefore probably originated from complementarity. 5Despite enhanced water use in the more diverse communities, plant survival was significantly less, affecting all species alike. Physiological stress, recorded as photochemical efficiency of photosystem II electron transport, was significantly greater. Before the heat wave, the changes in biomass composition that coincided with increasing S did not favour species that would later prove intrinsically sensitive or insensitive. 6Complementarity in resource use for biomass production had a cost in terms of reduced survival under stress, despite the likelihood of complementarity in water acquisition during exposure. The greater loss of individuals from the more diverse grasslands suggests enhanced risk of local extinction. [source] Gender, social capital and location: understanding the interactionsINTERNATIONAL JOURNAL OF SOCIAL WELFARE, Issue 2 2007Karen Healy In recent years, governments in many post-industrial nations have re-discovered ,community'. Social capital and neighbourhood renewal are key concepts underpinning policies aimed at building the capacities of communities to respond to the problems facing them. Despite the apparent consensus amongst Anglo-American governments about the use of social capital, and related concepts, as a guide for policy formulation these ideas remain hotly contested amongst social policy commentators. Against a general backdrop of disquiet about the application of social capital initiatives to communities facing significant social and economic challenges, some commentators highlight the curious inattention to gender in debates about social capital. This is all the more troubling given the apparent reliance of social capital initiatives on the informal network-building activities often undertaken by women. In this article we present findings from an empirical study of social capital creation across four geographically diverse communities. We show that the relationship between gender and social capital is complex. We argue that the ,one-size-fits-all' approach to social capital formulation fails to recognise gendered patterns of social capital formulation, but so, too, do analyses of gender that neglect the complex interactions between gender and other factors, particularly location, age and income. We argue for approaches to policy formulation that recognise local differences, including differences between and amongst men and women in social capital creation. [source] Loving America and Longing for Home: Isma'il al-Faruqi and the Emergence of the Muslim Diaspora in North AmericaINTERNATIONAL MIGRATION, Issue 2 2004Behrooz Ghamari-Tabrizi In this paper, I weave the experience of an emerging community of Muslim diaspora around a biographical narrative of the Muslim activist and scholar Isma'il al-Faruqi. Through this narrative, I illustrate that the diasporic experience begins in the place of origin and it does not inevitably lead toward a perpetual hybridization. The latter point is particularly significant because notions of diaspora and hybridity are conceptually linked and are often understood as a unidirectional cutting and mixing between the West and the East, or between the modern and the traditional. Al-Faruqi's experience shows that, in a Fanonian sense of colonialism, diasporic experience conveys living as a "stranger", at and away from home. The postcolonial condition has made it possible for ethnically diverse communities of Muslims to reside in the West, but maintain strong connections with their place of origin. Adopting the allegory of the Prophet's migration or hijra, al-Faruqi constructed a fantastic notion of the ummah and a normative homo islamicus subject. Although he was profoundly influenced by the diversity of the Muslim Student Associations' constituency, al-Faruqi encouraged Muslims to transcend their differences and sought to conceive a discursively homogenous ummah. Ultimately, however, his project failed because it did not correspond to real life experiences of Muslims of the West. Historically, Muslim communities have negotiated the boundaries of Muslimhood and the social responsibilities it entails, both in their homelands and in their new home in the West , a new home that increasingly becomes hostile to their presence, and thereby further complicates their triangular diaspora/host society/homeland relationship. [source] Response of recruitment to light availability across a tropical lowland rain forest communityJOURNAL OF ECOLOGY, Issue 6 2009Nadja Rüger Summary 1. ,Many hypotheses about species coexistence involve differential resource use and trade-offs in species' life-history traits. Quantifying resource use across most species in diverse communities, although, has seldom been attempted. 2. ,We use a hierarchical Bayesian approach to quantify the light dependence of recruitment in 263 woody species in a 50-ha long-term forest census plot in Panama. Data on sapling recruitment were obtained using the 1985,1990 and 1990,1995 census intervals. Available light was estimated for each recruit from yearly censuses of canopy density. 3. ,We use a power function (linear log,log relationship) to model the light effect on recruitment. Different responses of recruitment to light are expressed by the light effect parameter b. The distribution of b had a central mode at 0.8, suggesting that recruitment of many species responds nearly linearly to increasing light. 4. ,Nearly every species showed increases in recruitment with increasing light. Just nine species (3%) had recruitment declining with light, while 198 species (75%) showed increasing recruitment in both census intervals. Most of the increases in recruitment were decelerating, i.e. the increase was less at higher light (b < 1). In the remaining species, the response to light varied between census intervals (24 species) or species did not have recruits in both intervals (41 species). 5. ,Synthesis. Nearly all species regenerate better in higher light, and recruitment responses to light are spread along a continuum ranging from modest increase with light to a rather strict requirement for high light. These results support the hypothesis that spatio-temporal variation in light availability may contribute to the diversity of tropical tree species by providing opportunities for niche differentiation with respect to light requirements for regeneration. [source] The role of genotypic diversity in determining grassland community structure under constant environmental conditionsJOURNAL OF ECOLOGY, Issue 5 2007RAJ WHITLOCK Summary 1A recent experiment varied the genetic diversity of model grassland communities under standardized soil and management conditions and at constant initial species diversity. After 5 years' growth, genetically diverse communities retained more species diversity and became more similar in species composition than genetically impoverished communities. 2Here we present the results of further investigation within this experimental system. We proposed that two mechanisms , the first invoking genetically determined and constant differences in plant phenotypes and the second invoking genotype,environment interactions , could each underpin these results. This mechanistic framework was used as a tool to interpret our findings. 3We used inter-simple sequence repeat (ISSR) DNA markers to confirm which of the individuals of six study species initially included in the model communities were unique genotypes. We then used the molecular markers to assess the survival and abundance of each genotype at the end of the 5-year experimental period. 4The DNA marker data were used to create, for the first time, a genotype abundance hierarchy describing the structure of a community at the level of genotypes. This abundance hierarchy revealed wide variation in the abundance of genotypes within species, and large overlaps in the performance of the genotypes of different species. 5Each genotype achieved a consistent level of abundance within genetically diverse communities, which differed from that attained by other genotypes of the same species. The abundance hierarchy of genotypes within species also showed consistency across communities differing in their initial level of genetic diversity, such that species abundance in genetically impoverished communities could be predicted, in part, by genotypic identity. 6Three species (including two canopy-dominants) experienced shifts in their community-level genotype abundance hierarchies that were consistent with an increased influence of genotype,environment interactions in genetically impoverished communities. 7Our results indicate that under relatively constant environmental conditions the species abundance structure of plant communities can in part be predicted from the genotypic composition of their component populations. Genotype,environment interactions also appear to shape the structure of communities under such conditions, although further experiments are needed to clarify the magnitude and mechanism of these effects. [source] Effects of genetic impoverishment on plant community diversityJOURNAL OF ECOLOGY, Issue 5 2003Rosemary E. Booth Summary 1Established individuals removed at random from populations of 11 long-lived herbaceous species coexisting in a local area of ancient limestone pasture at Cressbrookdale in North Derbyshire were subjected to clonal propagation to produce stocks of genetically identical individuals sufficient to create 36 model communities identical in species composition but widely contrasted in genetic diversity. 2Three levels of genetic diversity were imposed. In one treatment, all individuals of each species were genetically unique. The second contained four randomly selected genotypes of each species. In the third, there was no genetic diversity in any of the species but each community contained a unique combination of genotypes. 3Over a period of 5 years the communities were allowed to develop in microcosms containing natural rendzina soil and exposed to a standardized regime of simulated grazing and trampling. The treatments were maintained by the removal of flowers, immature seed-heads and seedlings originating from the seed-bank and seed rain. Point quadrat surveys were used to monitor changes in species composition and diversity in the three experimental treatments. 4During the experiment a distinction rapidly developed between five canopy dominants and five subordinates, a process that caused the vegetation structure to closely resemble that occurring at Cressbrookdale. 5A gradual loss of species diversity occurred in all three treatments but by the end of the fifth growing season species diversity was higher in the most genetically diverse communities. 6Ordination of the 36 communities at intervals over a 5-year period revealed a gradual convergence in the species composition of the 4-genotype and 16-genotype communities and this effect was more strongly developed in the latter. A comparable process was not observed in the 1-genotype communities, suggesting that interaction between particular genotypes of different species in local neighbourhoods may be an essential part of the mechanism that determines the predictable composition of a mature pasture community. 7It is concluded that, under the conditions of this experiment, genetic diversity within component species reduced the rate at which species diversity declined. The relative importance in this effect of factors such as greater disease resistance and moderated competitive interactions remains uncertain. [source] Rethinking diversity in learning science: The logic of everyday sense-makingJOURNAL OF RESEARCH IN SCIENCE TEACHING, Issue 5 2001Beth Warren There are many ways to understand the gap in science learning and achievement separating low-income, ethnic minority and linguistic minority children from more economically privileged students. In this article we offer our perspective. First, we discuss in broad strokes how the relationship between everyday and scientific knowledge and ways of knowing has been conceptualized in the field of science education research. We consider two dominant perspectives on this question, one which views the relationship as fundamentally discontinuous and the other which views it as fundamentally continuous. We locate our own work within the latter tradition and propose a framework for understanding the everyday sense-making practices of students from diverse communities as an intellectual resource in science learning and teaching. Two case studies follow in which we elaborate this point of view through analysis of Haitian American and Latino students' talk and activity as they work to understand metamorphosis and experimentation, respectively. We conclude with a discussion of the implications of this new conceptualization for research on science learning and teaching. © 2001 John Wiley & Sons, Inc. J Res Sci Teach 38: 529,552, 2001 [source] Future research on dementia relating to culturally and linguistically diverse communitiesAUSTRALASIAN JOURNAL ON AGEING, Issue 3 2009Lee-Fay Low About one in five older Australians were born overseas. However, there has been very little information published in Australia or internationally about dementia in persons from culturally and linguistically diverse (CALD) backgrounds. This limits our ability to plan for and provide evidence-based medical care, social care and aged care services to persons from CALD backgrounds. This paper describes challenges to conducting CALD dementia research; these include sampling, having valid instruments and costs. Nine key research recommendations in the areas of epidemiology, community knowledge, carers, service delivery, screening and assessment, medical management, residential aged care and minority CALD reached by consensus by an expert group are presented. The paper closes with some strategies to encourage CALD research. The material presented here will provide guidance for future research endeavours. [source] Microbial functional structure of Montastraea faveolata, an important Caribbean reef-building coral, differs between healthy and yellow-band diseased coloniesENVIRONMENTAL MICROBIOLOGY, Issue 2 2010Nikole E. Kimes Summary A functional gene array (FGA), GeoChip 2.0, was used to assess the biogeochemical cycling potential of microbial communities associated with healthy and Caribbean yellow band diseased (YBD) Montastraea faveolata. Over 6700 genes were detected, providing evidence that the coral microbiome contains a diverse community of archaea, bacteria and fungi capable of fulfilling numerous functional niches. These included carbon, nitrogen and sulfur cycling, metal homeostasis and resistance, and xenobiotic contaminant degradation. A significant difference in functional structure was found between healthy and YBD M. faveolata colonies and those differences were specific to the physical niche examined. In the surface mucopolysaccharide layer (SML), only two of 31 functional categories investigated, cellulose degradation and nitrification, revealed significant differences, implying a very specific change in microbial functional potential. Coral tissue slurry, on the other hand, revealed significant changes in 10 of the 31 categories, suggesting a more generalized shift in functional potential involving various aspects of nutrient cycling, metal transformations and contaminant degradation. This study is the first broad screening of functional genes in coral-associated microbial communities and provides insights regarding their biogeochemical cycling capacity in healthy and diseased states. [source] Soil CO2 flux and photoautotrophic community composition in high-elevation, ,barren' soilENVIRONMENTAL MICROBIOLOGY, Issue 3 2009Kristen R. Freeman Summary Soil-dominated ecosystems, with little or no plant cover (i.e. deserts, polar regions, high-elevation areas and zones of glacial retreat), are often described as ,barren', despite their potential to host photoautotrophic microbial communities. In high-elevation, subnival zone soil (i.e. elevations higher than the zone of continuous vegetation), the structure and function of these photoautotrophic microbial communities remains essentially unknown. We measured soil CO2 flux at three sites (above 3600 m) and used molecular techniques to determine the composition and distribution of soil photoautotrophs in the Colorado Front Range. Soil CO2 flux data from 2002 and 2007 indicate that light-driven CO2 uptake occurred on most dates. A diverse community of Cyanobacteria, Chloroflexi and eukaryotic algae was present in the top 2 cm of the soil, whereas these clades were nearly absent in deeper soils (2,4 cm). Cyanobacterial communities were composed of lineages most closely related to Microcoleus vaginatus and Phormidium murrayi, eukaryotic photoautotrophs were dominated by green algae, and three novel clades of Chloroflexi were also abundant in the surface soil. During the light hours of the 2007 snow-free measurement period, CO2 uptake was conservatively estimated to be 23.7 g C m,2 season,1. Our study reveals that photoautotrophic microbial communities play an important role in the biogeochemical cycling of subnival zone soil. [source] Bacteria,diet interactions affect longevity in the medfly ,Ceratitis capitataJOURNAL OF APPLIED ENTOMOLOGY, Issue 9-10 2008M. Ben-Yosef Abstract Mediterranean fruit flies (Ceratitis capitata Wiedemann, Dipt.: Tephritidae) harbour a diverse community of bacteria in their digestive system. This microbiota may have important functions impacting on the fly's fitness. Recently, we described the effect of eliminating intestinal bacteria on the reproductive success of C. capitata males and females. Here, we expand the view on the nature of fly,bacteria interactions by examining the effect of bacteria on male and female longevity. Antibiotics were used to suppress the gut bacterial community and mortality rates were compared between antibiotic-treated and non-treated flies when either nutritionally stressed (maintained on sugar) or provided with a full diet. These tests revealed that eliminating the gut bacterial population prolonged longevity, but only when flies were nutritionally stressed, indicating that the effect of bacteria on lifespan was diet dependent. Considering these results in light of other known effects of bacteria on fitness components of the fly demonstrates a cost-benefit relationship between C. capitata and its gut microbiota. [source] Ecological recovery of an afromontane forest in south- western UgandaAFRICAN JOURNAL OF ECOLOGY, Issue 2004J. B. Lejju Abstract A study of the regeneration of an afromontane forest was carried out in Mgahinga Gorilla National Park (MGNP), south-western Uganda. The area landscape has been subjected to agricultural encroachment for the last 50 years. The landscape was changed by terracing and removing the indigenous vegetation and replacing it with exotic tree species. Stratified random sampling was employed in sampling the vegetation. There was a significant difference in species richness and density in the three habitat types. The natural forest supported the highest stem density (75%) and the lowest stem density (4%) was recorded under exotic woodlots. Seedlings (<2 cm, diameter at breast height) accounted for the majority of juveniles in the three habitats. The natural forest had the highest density (24,625 seedlings ha,1) and exotic woodlots supported the lowest stem density (1350 seedlings ha,1). The level of regeneration in the encroachment area is influenced by the intensity of cultivation and soil nutrients. The advanced growth beneath the exotic woodlots, especially black wattle (Acacia mearnsii) and Eucalyptus sp. stands is relatively impoverished. This condition beneath the exotic species suggests that a low diverse community of native species is able to exploit this environment. [source] Fate of epiphytes on phorophytes with different architectural characteristics along the perturbation gradient of Sabal mexicana forests in Veracruz, MexicoJOURNAL OF VEGETATION SCIENCE, Issue 1 2010A. Aguirre Abstract Question: Vascular epiphytes and hemiepiphytes (E/HE) in neotropical forests account for a large fraction of plant richness, but little is known of how the interplay between phorophyte architectural characteristics and habitat perturbation affect communities of E/HE. Location: Sabal mexicana forests in a coastal area of Veracruz, Mexico. Methods: We compared communities of E/HE on phorophytes with different architectural characteristics , the palm S. mexicana and non-palm phorophytes , in three environments: conserved sites, perturbed sites and small regenerated forest fragments. We combined traditional (abundance, species richness, similarity and complementarity indices) and more recent (phylogenetic diversity) metrics to describe the communities of E/HE. Results: Overall, we recorded 924 E/HE individuals (nine families, 16 genera and 21 species). The abundance and species richness of E/HE was higher on palms than on non-palm phorophytes. Abundance-based complementarities between phorophytes and sites were high. We detected clear changes in community structure of E/HE with habitat perturbation, but there were no effects on the phylogenetic diversity of the E/HE community. Palm phorophytes hosted a more phylogenetically diverse community of E/HE than did non-palm phorophytes. Conclusions: Palm phorophytes are key elements supporting the conservation of resilient communities of E/HE in S. mexicana forest. Habitat fragmentation has a strong effect on the structure of the E/HE community in S. mexicana forests. Ferns are the group of epiphytes most severely affected by habitat perturbation, but we detected no significant effect on the phylogenetic diversity of the community. [source] Effects of Mycorrhizae and Nontarget Organisms on Restoration of a Seasonal Tropical Forest in Quintana Roo, Mexico: Factors Limiting Tree EstablishmentRESTORATION ECOLOGY, Issue 2 2005Michael F. Allen Abstract We initiated a study of the effects of mycorrhizal fungal community composition on the restoration of tropical dry seasonal forest trees. Tree seedlings were planted in a severely burned experimental site (1995 fire) during the growing season of 1998 at the El Edén Ecological Reserve, in north Quintana Roo, Mexico. Seedlings of Leucaena leucocephala, Guazuma ulmifolia, Caesalpinia violacea, Piscidia piscipula, Gliricidia sepium, and Cochlospermum vitifolium were germinated in steam-sterilized soil and either remained uninoculated (nonmycorrhizal at transplanting) or were inoculated with mycorrhizal fungi in soils from early-seral (recently burned) or late-seral (mature forest) inoculum. Inoculum from the early-seral soil was largely Glomus spp., whereas a diverse community of arbuscular mycorrhizal fungi were reintroduced from the mature forest including species of Scutellospora, Gigaspora, Glomus, Sclerocystis, and Acaulospora. Plants grew better when associated with the mature forest inoculum, unlike a previous experiment in which plants grew taller with the early-seral inoculum. Reasons for the different responses include a less-intense burn resulting in more residual organic matter. In addition to mycorrhizal responses, plants were severely affected by deer browsing. One tree species, C. vitifolium found in the region but not in the reserve, was eliminated by a resident fungal facultative pathogen. Several practical conclusions for restoration can be made. The common nursery practice of soil sterilization may be detrimental because it eliminates beneficial mycorrhizal fungi; species not native to the site may not survive because they may not be adapted to the local pathogens; and herbivory can be severe depending on the landscape context of the restoration. [source] Microbial community structure in a biofilm anode fed with a fermentable substrate: The significance of hydrogen scavengersBIOTECHNOLOGY & BIOENGINEERING, Issue 1 2010Prathap Parameswaran Abstract We compared the microbial community structures that developed in the biofilm anode of two microbial electrolysis cells fed with ethanol, a fermentable substrate,one where methanogenesis was allowed and another in which it was completely inhibited with 2-bromoethane sulfonate. We observed a three-way syntrophy among ethanol fermenters, acetate-oxidizing anode-respiring bacteria (ARB), and a H2 scavenger. When methanogenesis was allowed, H2 -oxidizing methanogens were the H2 scavengers, but when methanogenesis was inhibited, homo-acetogens became a channel for electron flow from H2 to current through acetate. We established the presence of homo-acetogens by two independent molecular techniques: 16S rRNA gene based pyrosequencing and a clone library from a highly conserved region in the functional gene encoding formyltetrahydrofolate synthetase in homo-acetogens. Both methods documented the presence of the homo-acetogenic genus, Acetobacterium, only with methanogenic inhibition. Pyrosequencing also showed a predominance of ethanol-fermenting bacteria, primarily represented by the genus Pelobacter. The next most abundant group was a diverse community of ARB, and they were followed by H2 -scavenging syntrophic partners that were either H2 -oxidizing methanogens or homo-acetogens when methanogenesis was suppressed. Thus, the community structure in the biofilm anode and suspension reflected the electron-flow distribution and H2 -scavenging mechanism. Biotechnol. Bioeng. 2010;105: 69,78. © 2009 Wiley Periodicals, Inc. [source] | ||||||||||||||||||||||||||||