Study On The Microbial Diversity Of Sediments From The West Philippine Sea Bicol Shelf And Manus Basin

The archaeal diversity and phylogenesis of the sediments samples from the Bicol shelf of West Philippine Sea for West Pacific Ocean were investigated and analyzed by using the 16S rRNA gene clone libraries method. Total 465 efficient cloning sequences were obtained and divided into 63 OTUs. Phylogenetic results showed that Archaea sequences were from Crenarchaeota and Euryarchaeota. The majority of archaeal phylotypes were Marine Benthic Group B (MBGB),Marine Group I (MGI),Miscellaneous Crenarchaeotic Group (MCG),and Marine Benthic Group D. Additional few sequences fell into Marine Hydrothermal Vent Group (MHVG). The results indicated that the sediment samples of five different layers has only five groups of archaea. Achaeal community diversity was low, and dominant archaea have some differences in each layers.To study the archaeal diversity and bacterial diversity of hydrothermal sediments of Manus Basin, we investigated the diversity of archaeal 16S rRNA and bacterialn16S rRNA genes sequences by using a PCR-based cloning approach. Phylogenetic and statistic analysis of clone sequences showed that: the archaeal diversity of hydrothermal sediments of Manus Basin has eight groups of archaea. The majority of archaeal phylotypes were MBGB. Additional few sequences fell into MCG,Methanosarcina,MBGE,MBGD,VALШand unknown archaea. Diversity of bacteria was detected in this hydrothermal sediment and at least 15 major lineages of the bacteria domain were obtained. They are the phyla of the Proteobcteria, Planctomycetes, Actinobacteria (high G+C Gram-positive bacteria), Bacteroidetes, Chloroflexi, Gemmatimonadetes, Chlorobi, Spirochaetaeeae, Verrucomicrobia, Deferribacteres, Nitrospirae,Candidate division OP8, candidate division OD1, candidate division TM6,candidate division WS3. The division of the Proteobcteria contained five subdivisions including theα-,γ-,δ-,β- andε-Proteobateria subdivisions in our libraries and it was mainlyγ- andδ- Proteobcteria . Proteobcteria bacteria were common in different deep-sea environments.The result showed that Manus Basin hydrothermal sediments has rich microbial flora and unrecognized new species.Comparative analysis demonstrated that: Archaea sequences of Bicol shelf and Manus Basin were both mainly Crenarchaeota. MBGB is the dominant species in the volcanic ash layer. However, two volcanic ash layers Bicol Shelf diversity of Archaea compared to hydrothermal volcanic ash layers of Archaea population diversity are lower, this may be because of different sea, different temperatures, different depth and ability to adapt to the environment result. Archaeal diversity of Manus basin is lower than the bacterial diversity, bacteria may be dominated, which may be related to the submarine hydrothermal temperature and microbial adaptation.