scholarly journals Exploring the interaction network of a synthetic gut bacterial community

2021 ◽  
Author(s):  
Anna S. Weiss ◽  
Anna G. Burrichter ◽  
Abilash Chakravarthy Durai Raj ◽  
Alexandra von Strempel ◽  
Chen Meng ◽  
...  

AbstractA key challenge in microbiome research is to predict functionality from microbial community composition. As central microbiota functions are determined by bacterial community networks it is important to gain insight into the principles that govern bacteria-bacteria interactions. Here, we focused on growth and metabolic interactions of the Oligo-Mouse-Microbiota (OMM12) synthetic bacterial community, which is increasingly used as model system in gut microbiome research. Using a bottom-up approach, we uncovered the directionality of strain-strain interactions in mono- and pairwise co-culture experiments, as well as in community batch culture. Metabolomics analysis of spent culture supernatant of individual strains in combination with genome-informed pathway reconstruction provided insights into the metabolic potential of the individual community members. Thereby, we could show that the OMM12 interaction network is shaped by both, exploitative and interference competition in vitro. In particular, Enterococcus faecalis KB1 was identified as important driver of community composition by affecting the abundance of several other consortium members. Together, this study gives fundamental insight into key drivers and mechanistic basis of the OMM12 interaction network, which serves as knowledge base for future mechanistic studies.

2021 ◽  
Author(s):  
Anna S. Weiss ◽  
Anna G. Burrichter ◽  
Abilash Chakravarthy Durai Raj ◽  
Alexandra von Strempel ◽  
Chen Meng ◽  
...  

AbstractA key challenge in microbiome research is to predict the functionality of microbial communities based on community membership and (meta)-genomic data. As central microbiota functions are determined by bacterial community networks, it is important to gain insight into the principles that govern bacteria-bacteria interactions. Here, we focused on the growth and metabolic interactions of the Oligo-Mouse-Microbiota (OMM12) synthetic bacterial community, which is increasingly used as a model system in gut microbiome research. Using a bottom-up approach, we uncovered the directionality of strain-strain interactions in mono- and pairwise co-culture experiments as well as in community batch culture. Metabolic network reconstruction in combination with metabolomics analysis of bacterial culture supernatants provided insights into the metabolic potential and activity of the individual community members. Thereby, we could show that the OMM12 interaction network is shaped by both exploitative and interference competition in vitro in nutrient-rich culture media and demonstrate how community structure can be shifted by changing the nutritional environment. In particular, Enterococcus faecalis KB1 was identified as an important driver of community composition by affecting the abundance of several other consortium members in vitro. As a result, this study gives fundamental insight into key drivers and mechanistic basis of the OMM12 interaction network in vitro, which serves as a knowledge base for future mechanistic in vivo studies.


mSystems ◽  
2019 ◽  
Vol 4 (6) ◽  
Author(s):  
Holly L. Lutz ◽  
Elliot W. Jackson ◽  
Paul W. Webala ◽  
Waswa S. Babyesiza ◽  
Julian C. Kerbis Peterhans ◽  
...  

ABSTRACT Recent studies of mammalian microbiomes have identified strong phylogenetic effects on bacterial community composition. Bats (Mammalia: Chiroptera) are among the most speciose mammals on the planet and the only mammal capable of true flight. We examined 1,236 16S rRNA amplicon libraries of the gut, oral, and skin microbiota from 497 Afrotropical bats (representing 9 families, 20 genera, and 31 species) to assess the extent to which host ecology and phylogeny predict microbial community similarity in bats. In contrast to recent studies of host-microbe associations in other mammals, we found no correlation between chiropteran phylogeny and bacterial community dissimilarity across the three anatomical sites sampled. For all anatomical sites, we found host species identity and geographic locality to be strong predictors of microbial community composition and observed a positive correlation between elevation and bacterial richness. Last, we identified significantly different bacterial associations within the gut microbiota of insectivorous and frugivorous bats. We conclude that the gut, oral, and skin microbiota of bats are shaped predominantly by ecological factors and do not exhibit the same degree of phylosymbiosis observed in other mammals. IMPORTANCE This study is the first to provide a comprehensive survey of bacterial symbionts from multiple anatomical sites across a broad taxonomic range of Afrotropical bats, demonstrating significant associations between the bat microbiome and anatomical site, geographic locality, and host identity—but not evolutionary history. This study provides a framework for future systems biology approaches to examine host-symbiont relationships across broad taxonomic scales, emphasizing the need to elucidate the interplay between host ecology and evolutionary history in shaping the microbiome of different anatomical sites.


2018 ◽  
Vol 10 (8) ◽  
pp. 156
Author(s):  
Sofia Magalhaes Moreira ◽  
Claudia Braga Pereira Bento ◽  
Analice Claudia Azevedo ◽  
Hilario C. Mantovani

Antibiotics are used as feed additives for cattle to alter rumen fermentation and increase weight gain. However, this practice can potentially lead to the presence of antibiotic residues in milk and meat and the selection of multiresistant bacteria. Bacteriocins have been suggested as an alternative to antibiotics used in animal production. This work aimed to evaluate the in vitro effects of bovicin HC5 and virginiamycin on ruminal fermentation and on microbial community composition. Ruminal fluid was collected from fistulated cows fed corn silage and incubated with Trypticase (15 g L-1). Cultures treated with bovicin HC5 or virginiamycin decreased (P < 0.05) ammonia accumulation by 47.46% and 66.17%, respectively. Bovicin HC5 and virginiamycin also decreased (P < 0.05) the concentration of organic acids and gas production, but the effects were somewhat distinct. Molecular fingerprinting of the microbial community using PCR-DGGE revealed that community structure varied between treatments and were distinct from the controls. These results demonstrate that bovicin HC5 and virginiamycin have distinct effects on ruminal fermentation and modify differently the microbial community composition. These results also expand the knowledge about the effects of antibiotics and bacteriocins on bacterial and archaeal communities involved in protein metabolism in the rumen.


2003 ◽  
Vol 69 (2) ◽  
pp. 835-844 ◽  
Author(s):  
Wietse de Boer ◽  
Patrick Verheggen ◽  
Paulien J. A. Klein Gunnewiek ◽  
George A. Kowalchuk ◽  
Johannes A. van Veen

ABSTRACT Most soils inhibit fungal germination and growth to a certain extent, a phenomenon known as soil fungistasis. Previous observations have implicated microorganisms as the causal agents of fungistasis, with their action mediated either by available carbon limitation (nutrient deprivation hypothesis) or production of antifungal compounds (antibiosis hypothesis). To obtain evidence for either of these hypotheses, we measured soil respiration and microbial numbers (as indicators of nutrient stress) and bacterial community composition (as an indicator of potential differences in the composition of antifungal components) during the development of fungistasis. This was done for two fungistatic dune soils in which fungistasis was initially fully or partly relieved by partial sterilization treatment or nutrient addition. Fungistasis development was measured as restriction of the ability of the fungi Chaetomium globosum, Fusarium culmorum, Fusarium oxysporum, and Trichoderma harzianum to colonize soils. Fungistasis did not always reappear after soil treatments despite intense competition for carbon, suggesting that microbial community composition is important in the development of fungistasis. Both microbial community analysis and in vitro antagonism tests indicated that the presence of pseudomonads might be essential for the development of fungistasis. Overall, the results lend support to the antibiosis hypothesis.


2021 ◽  
Author(s):  
Sven P. Tobias-Hünefeldt ◽  
Stephen R. Wing ◽  
Federico Baltar ◽  
Sergio E. Morales

Abstract Fjords are semi-enclosed marine systems with unique physical conditions that influence microbial community composition and structure. Pronounced organic matter and physical condition gradients within fjords provide a natural laboratory for the study of changes in microbial phylogeny and metabolic potential in response to environmental conditions. Photosynthetic production in euphotic zones sustains deeper aphotic microbial activity via organic matter sinking, augmented by large terrestrial inputs. We profiled microbial functional potential (Biolog Ecoplates), bacterial abundance, heterotrophic production (3H-Leucine incorporation), and prokaryotic/eukaryotic community composition (16S and 18S rRNA amplicon gene sequencing) to link metabolic potential, activity, and community composition to known community drivers. Similar factors shaped metabolic potential, activity and community (prokaryotic and eukaryotic) composition across surface/near surface sites. However, increased metabolic diversity at near bottom (aphotic) sites reflected an organic matter influence from sediments. Photosynthetically produced particulate organic matter shaped the upper water column community composition and metabolic potential. In contrast, microbial activity at deeper aphotic waters were strongly influenced by other organic matter imput than sinking marine snow (e.g. sediment resuspension of benthic organic matter, remineralisation of terrestrially derived organic matter, etc.), severing the link between phylogeny and metabolic potential. Taken together, different organic matter sources shape microbial activity, but not community composition, in New Zealand fjords.


2014 ◽  
Vol 81 (4) ◽  
pp. 1463-1471 ◽  
Author(s):  
Stefan Thiele ◽  
Bernhard M. Fuchs ◽  
Rudolf Amann ◽  
Morten H. Iversen

ABSTRACTDue to sampling difficulties, little is known about microbial communities associated with sinking marine snow in the twilight zone. A drifting sediment trap was equipped with a viscous cryogel and deployed to collect intact marine snow from depths of 100 and 400 m off Cape Blanc (Mauritania). Marine snow aggregates were fixed and washedin situto prevent changes in microbial community composition and to enable subsequent analysis using catalyzed reporter deposition fluorescencein situhybridization (CARD-FISH). The attached microbial communities collected at 100 m were similar to the free-living community at the depth of the fluorescence maximum (20 m) but different from those at other depths (150, 400, 550, and 700 m). Therefore, the attached microbial community seemed to be “inherited” from that at the fluorescence maximum. The attached microbial community structure at 400 m differed from that of the attached community at 100 m and from that of any free-living community at the tested depths, except that collected near the sediment at 700 m. The differences between the particle-associated communities at 400 m and 100 m appeared to be due to internal changes in the attached microbial community rather thande novocolonization, detachment, or grazing during the sinking of marine snow. The new sampling method presented here will facilitate future investigations into the mechanisms that shape the bacterial community within sinking marine snow, leading to better understanding of the mechanisms which regulate biogeochemical cycling of settling organic matter.


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