BioGenomics2017 - Global Biodiversity Genomics Conference
February 21-23, 2017
Smithsonian National Museum of Natural History | Washington, D.C.

Program - Single Session


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16
Microbiomics

Room: Salon 2, Marriott Hotel

09:00 - 10:30

Moderator: Jack Okamura



16.1  09:10  Surface microbiomes of crustose coralline algae shift in response to ocean acidification and macroalgae with implications for coral recruitment . Sneed JM*, Smithsonian Marine Station; Campbell JE, Smithsonian Marine Station; Johnston LN, University of Delaware; Paul VJ, Smithsonian Marine Station

Crustose coralline algae (CCA) are vital to healthy coral reef ecosystems and provide settlement cues for a variety of invertebrate larvae including corals. For some corals, settlement, which is an integral part of the recruitment process, appears to be dependent on the presence of chemical cues produced by biofilm bacteria associated with CCA. Both macroalgal presence and ocean acidification (OA) have detrimental impacts on coral settlement, but the extent to which these stressors impact bacterial communities associated with settlement substrata has been underexplored. Further, these stressors will not occur in isolation, and understanding the implications of these factors in combination is critical. We exposed the crustose coralline alga (CCA) <em>Hydrolithon beorgesenii</em> to direct macroalgal contact and OA separately and in combination. There were significant changes in the core microbiomes of CCA surfaces exposed to low pH and macroalgae as compared to those exposed to low pH and a fake-plant control that corresponded to significant differences in coral larval settlement. Given the increasing evidence that bacteria provide important settlement cues for some corals, it is likely that changes in the settlement response of corals to surfaces treated with macroalgae and OA may be linked to shifts in the bacterial communities on these surfaces.


16.2  09:30  Changes in soil microbial diversity across land use types in wet and dry tropical forests of Panama. Saltonstall K*, STRI; Turner B, STRI; van Breugel M, STRI; Hall J, STRI

Forest recovery following abandonment of agricultural lands in the tropics depends on a variety of factors, including the surrounding vegetation communities, levels of soil degradation, and natural disturbance processes. Belowground microbial communities may also play an important role in the recovery of aboveground forest communities, as microbes may either enhance or postpone forest recovery. Soil samples were collected from three land-use types (pasture, young secondary and old secondary forests, n=12 in each) in the Agua Salud landscape near Colon, Panama (wet forest) and the Azuero Peninsula near Pedasi (dry forest). We investigated changes in soil bacterial and fungal communities across these land use types by sequencing 16s and ITS metagenomic libraries on an Illumina MiSeq. Nutrients and pH of each soil sample, as well as aboveground vegetation cover at each site were also analyzed. We have found that at the community level, the bacteria and fungi of pasture soils are distinct from old secondary forest soils, with young secondary forest plots having communities representative of both pastures and older forest. These sites are ideal for looking at the effect of land use and vegetation cover on soil microbial communities as they contain a mosaic of landscapes across an area with relatively homogeneous soils and other edaphic factors. Detailed analysis of soil properties and vegetation cover will enhance our understanding of the role that soil microbial communities may play in successional processes of tropical forests.


16.3  09:50  Unprecedented eukaryotic gut microbiome diversity within long-tailed macaques (Macaca fascicularis) in southeast Asia. Hollocher H*, University of Notre Dame; Wilcox J, University of Notre Dame

The majority of eukaryotes have been suggested to live on or in other hosts, but the diversity and ecology of these symbiotic eukaryotes remains consummately uncharacterized, despite unprecedented contemporary interest in prokaryotic microbiomes.  Key ecological roles played by eukaryotes in free-living systems and the ubiquity of parasitism, commensalism, and mutualism in eukaryotes suggest that symbiotic eukaryotes may make important contributions to host-associated communities.  While previous studies on the host-associated eukaryotic communities of vertebrates have reported low levels of diversity relative to both sympatric prokaryotic and free-living eukaryotic communities, these findings may be more indicative of differences in the methodologies used to characterize these communities than they are of actual ecological differences between these biological systems.  To assess the potential for such hidden diversity within guts of non-human primates, we utilize a novel Illumina sequencing approach to characterize eukaryotic diversity within the feces of wild long-tailed macaques (Macaca fascicularis) on two islands in southeast Asia: Singapore and Bali, Indonesia.  We report substantially higher levels of eukaryotic diversity than previously reported from the feces of primates.  All five super-groups of eukaryotic life were represented, and several taxonomic groups were found to be common across all samples, suggesting the existence of a core eukaryotic community with the capacity to perform consistent ecological functions within these macaque hosts.  Despite these commonalities, differences in eukaryotic gut assemblages were also detected that could be attributed to differences in host geography and diet. Our results are discussed within the context of how ecological guilds operating in the gut of macaques can drive community assemblage of symbiotic eukaryotes.


16.4  10:10  Introducing BASE: the Biomes of Australian Soil Environments soil microbial diversity database. Bissett A, CSIRO; Fitzgerald A, Bioplatforms Australia; Meintjes T, Murdoch University; Mele P, LaTrobe University; Reith F, CSIRO; Young A*, CSIRO

Microbial inhabitants of soils are important to ecosystem and planetary functions, yet there are large gaps in our knowledge of their diversity and ecology. The "Biomes of Australian Soil Environments" (BASE) project has generated a database of microbial diversity with associated metadata across extensive environmental gradients at continental scale. As the characterisation of microbes rapidly expands, the BASE database provides an evolving platform for interrogating microbial diversity and function. BASE currently provides amplicon sequences and associated contextual data for over 900 geographical locations encompassing all Australian states and territories, as well as a wide variety of bioregions, vegetation and land-use types. Amplicons target bacteria, archaea and general and fungal-specific eukaryotes. The growing database will soon include metagenomics data. Data are provided in both raw sequence (FASTQ) and analysed OTU table formats and are accessed via the project"s data portal, which provides a user-friendly search tool to quickly identify samples of interest. Processed data can be visually interrogated and intersected with other Australian diversity and environmental data using tools developed by the "Atlas of Living Australia". Developed within an open data framework, the BASE project is the first Australian soil microbial diversity database. The database will grow and link to other global efforts to explore microbial, plant, animal, and marine biodiversity. Its design and open access nature ensures that BASE will evolve as a valuable tool for documenting an often overlooked component of biodiversity and the many microbe-driven processes that are essential to sustain soil function and ecosystem services.




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