Diversity And Spatial Distribution Of The Microbial Community And Functional Genes Associated With The South China Sea Sponge Astrosclera Willeyana

The differences of living environment of marine microorganisms such as sea water and growth temperature, not only affect the existence of microbial groups, but also affect the production of microbial metabolites. Sponge-associated microorganisms on the different spatial parts of the sponge play different roles. Therefore, we suggest that the sponge-associated microorganisms have a spatial distribution, which of the microorganisms associated to the sponge will be different in different parts from cortex to the endosome.Diversity and spatial distribution of the microbial community and functional genes associated with the South China Sea sponge Astrosclera willeyana were investigated by molecular technology. We established 10 gene clone libraries of bacteria, archaea, actinomycetes, cyanobacteria 16S rRNA gene and two function genes from the cortex layer and the endosome layer of the sponge sample. Totally they were grouped into 49OTUs.South China Sea sponge Astrosclera willeyana associated bacteria have been identified belonging to seven gates: Planctomycetes, Cyanobacteria, Bacteroidetes, Firmicutes, Alpha-proteobacteria, Gamma-proteobacteria, and Actinobacteria which including Propionibacterineae, Frankineae, Micrococcineae, Corynebacterineae Acidimicrobiadae. Crenarchaeota and Euryarchaeota were also detected as well. Of all above, Bacteroidetes, Propionibacterineae and Frankineae were only detected in the endosome layer while Planctomycetes and Cyanobacteria were only detected in the cortex layer.Statistical analysis of sponge associated bacteria showed that differences of diversity and spatial distribution between cortex layer and endosome layer are significant. But the result of sponge associated archaea, which using a same statistical analysis, showed that diversity and spatial distribution between cortex layer and endosome layer did not show significant differences.Functional genes of the sponge associated microbes were also investigated by gene clone libraries. In South China Sea sponge library Astrosclera willeyana, we successfully established the functional gene clone libraries of nirS and amoA gene from the cortex layer and the endosome layer.The results showed that in the South China Sea sponge Astrosclera willeyana, amoA reflects a significant difference of spatial distribution between two layers while the functional gene nirS, and at the same time, did not reflect significant difference at all.In this study we found that in sponge Astrosclera willeyan, different, complex but unique microbial communities were associated, which had also a different spatial distribution. Especially the sponge associated bacteria showed a significant difference. It can provide new evidence for revealing the existence of microbial sponge selective retention mechanism and for exploring the differences of spatial distribution of sponge-associated microbial community from different spatial parts. It also made a useful attempt for targeted development of sponge natural product resources.