Exploring Surface Microbial Plankton Community In The Western North Pacific Ocean Using Metagenomic Methods

Microbes are abundant and diverse in marine ecosystem and play a crucial role in global biogeochemistry.Exploring marine microbial communities is critical to our understanding of microbial biomass,diversity,and ecosystem function.In the western North Pacific Ocean,the exploring of microbial metagenomics is still scant.In this paper,springtime 16S rRNA and summertime metagenomics of surface planktonic microbial communities were investigated in different waters in the western North Pacific Ocean.Summertime metagenomic studies of the surface planktonic microbial communities in the western North Pacific Ocean showed that a total 743,531 contigs were obtained,involving 44 phyla and more than 6,000 species,while the surface planktonic microbial communities in the spring involved 22 phyla.And the Cyanobacteria,Proteobacteria,Bacteroidetes and Actinobacteria were found to be the most abundant groups in the study area,accounting for more than 95%of the community.In spring,there were significant community structure differentiations in different waters.Prochlorococcus and Pseudoalteromonas exhibited relatively higher abundance in subtropical N-deficient regimes such as the subtropical countercurrent,while most Flavobacteriaceae and Rhodobacteraceae were found in the Kuroshio-Oyashio mixing zone.In summer.however,the surface planktonic bacteria communities were homogenized among different water types,while the relative abundance of Cyanobacteria increased to 68.6%?84.9%,becoming the absolute dominant group.These data suggest that the bacterial communities had distinct distribution patterns with spatially-and temporally-heterogeneous distributions in the surface of the western North Pacific Ocean.In this paper,the functional genes of summertime metagenomics were also analyzed and annotated.After gene prediction,1,566,315 unigenes were obtained in this study,including 123,763 core functional genes(Core),accounting for 7.9%of all unigenes.KEGG annotation results showed that the most representative metabolic process of microorganisms in the western North Pacific Ocean was Carbonhydrate metabolism,accounting for 20%of all metabolic pathways(73,993 unigenes),followed by Amino acid metabolism,accounting for 18%(68,689 unigenes).CAZymes annotation annotated a total of 10,142 unigenes(genomic data of 10 mixed samples),of which 5,358 unigenes belonged to Glycosyl Transferases(GT).In addition,the binning process in this study eventually obtained 37 metagenome assembled genomes(MAGs)with a high degree of integrity and low degree of contamination.They were annotated using NCBI nt and NCBI tax databases.It was found that 20 MAGs could be annotated to the Kingdom level,3 to the Phylum level,7 to the Class level,5 to the Family level,and 2 to the Species level.These findings contribute to the understanding of marine microbial distribution patterns,environmental adaptability and ecosystem functions.