Isolation,identification And Comparative Genomics Analysis Of Marine Verrucomicrobia

Verrucomicrobia phylum is one of the important phyla that has been clearly defined in the bacterial domain.It is the core member of the PVC group(Planctomycetes-Verrucomicrobia-Chlamydiae superpylum).The members of this pedigree are widely distributed in many habitats,but due to the lack of culturable groups,we have little understanding of their role in the environment.It is very important to mine the resources of Verrucomicrobia,accumulate more culturable strains and explore their metabolic characteristics.According to previous research,Verrucomicrobia was found in both sediments and algae samples.Therefore,this thesis takes Verrucomicrobia as the research object,Yuncheng Salt Lake samples,brown algae samples and sediments of Wendeng Salt Field were selected to design isolation media for Verrucomicrobia,polyphasic taxonomy and genome sequencing of potential new bacteria were performed.In addition,genome annotation and comparative analysis were performed on 40 strains of Verrucomicrobia phylum bacteria to further explore the potential characteristics and functions of Verrucomicrobia.The following results were obtained in this paper:1.Using Yuncheng Salt Lake samples,brown algae samples and sediment samples of Wendeng Salt Field as isolation materials,three different methods were used to isolate and culture Verrucomicrobia.A total of 1280 strains of bacteria were isolated and sequenced.There were 416 potential new bacteria whose 16S rRNA gene similarity was less than 98.6%,enriched the microbial resources.The potential new bacteria R534T was isolated from Yuncheng Salt Lake samples.The potential new bacteria 5K14T and 5K15T was isolated from brown algae samples.The potential new bacteria A430T and A504T was isolated from the sediment samples of Wendeng Salt Field.More resources of culturable new bacteria were accumulated for Verrucomicrobia.2.Polyphasic taxonomy analysis was carried out to determine the classification status of the three potential new bacteria.Strain 5K14T was identif1ed as a novel genus of Puniceicoccaceae,for which the name Marinisphaera coccoides gen.nov.,sp.nov.is proposed.Strain 5K15T was identified as a novel species of Oceaniferula,for which the name Oceaniferula flavus sp.nov.is proposed.Strain A504T was identified as a novel species of Haloferula,for which the name Haloferula rubra sp.nov.is proposed.3.The draft genomes of three potential new strains of Verrucomicrobia were sequenced.The functional genes,metabolic pathways,drug resistance genes,resistance mechanisms and secondary metabolite biosynthesis gene clusters of 40 strains were annotated by bioinformatics.According to the results of functional annotation and comparative genome analysis,Verrucomicrobia not only contains a variety of secondary metabolite synthesis gene clusters and drug resistance genes,but also has the ability of nitrite reduction and assimilate sulfate reduction.It is speculated that Verrucomicrobia may have potential ecological role in biogeochemical cycle.