Abstract: Host-microbe associations have been, and continue to be, an area of great interest. Even within a well-defined and well-studied gut microbial community, little attention has been paid to how the host’s gut may be co-evolving along the spectrum of microbial independence, ranging from loose and opportunistic host-microbe associations at one end versus intimate and specific associations at the other. This study explores factors that may influence gut microbial assembly and diversity among saproxylic and forest floor invertebrate hosts (velvet worms, wood cockroach, funnel web spiders) and its immediate environment, frass. All found in Tallaganda Region except for huntsman spiders. The study utilized the V4-V5 region of the 16S rRNA gene, fluorescence in situ hybridization (FISH), and feeding/fasting experiments in order to characterize gut microbial composition of the hosts and frass.

Low gut microbial abundance and highly variable gut microbial communities were observed across all velvet worms, funnel web and huntsman spiders’ gut samples, even with fasting/feeding experiments. The dominant bacterial phyla across all samples were Actinobacteria, Firmicutes, Proteobacteria, Spirochaetes, and Tenericutes. Interestingly, fluorescence in situ hybridization did not detect any bacterial signal in the velvet worm gut tissue. Coupled with the results of feeding experiments, our findings suggest that velvet worms and spiders are likely to have transient microbial communities, in contrast to the wood cockroach, which appears to have a well-established community of microbes.

Biolography: I am a broadly trained microbial ecologist who has worked with projects like marine microbial symbiosis, secondary metabolites for drug discovery and biofuels using chemistry, molecular biology, and FISH confocal microscopy; wetland restoration project as carbon sink using metagenomics and microbial biogeochemical approaches, especially in the greenhouse gas field measurements; marine water samples from San Pedro Ocean Time (SPOT) series which focus in spatio-temporal patterns of microbial and diversity productivity using field and lab measurements in conjunction with molecular, statistical tools, bioinformatics, and genomics.