Study On Species Diversity Of Marine Bacterial Community In Xiamen Coast And Predict Their Function

16S rRNA gene High-throughput sequencing technology has greatly promoted research of bacteria.This technology has been widely used in characterizing environmental sample composition and diversity.Marine bacteria play a vital role in the marine ecosystem,including the circulation of matter and the circulation of energy,as well as maintaining the stability of the marine ecosystem.In recent years,there have been more and more studies on bacterial communities in Xiamen coast,but all of them focus on the characteristics of microbial communities structure,and there have been few studies on the metabolic functions of bacteria in Xiamen coast.In this study,we collected surface seawater from Xiamen coast extracted DNA and then amplified the V3-V4 region of the 16S rRNA gene.The Illumina Miseq technology was used for sequencing and analysis.First,the composition and species diversity of marine bacterial communities in Xiamen coast were analyzed.Next,three different methods were used to predict the function of bacterial communities in Xiamen coasta.The main conclusions were as follows:(1)The bacterial communities in Xiamen were mainly composed of Proteobacteria,Actinomyces,Cyanophyta,and Bacteroidetes.The relative abundance of these four phylums accounted for 91%of the total samples.At the class level,the marine bacteria communities were mainly composed of ?-proteobacteria,y-proteobacteria,and actimicrobiia of actinomyces,flavobacteriia of bacteroidetes and 8-froteobacteria.The total relative abundance of these five classes was accounted for 76%of the entire sample in class level.(2)Analysis of a diversity indicated that the diversity of six samples was ordered:S19>S03>S08>S05>S12>S07.Correlation analysis of environmental parameters and bacterial communities indicated that there was no significant correlation between dissolved oxygen and bacterial communities;pH and NO3-concentration were positively correlated with Proteobacteria;NO2-concentration,T,DIS,PO43-concentration were positively correlated with Actinomyces,Bacteroidetes,and Chloroflexi;SAL was positively correlated with Cyanophyta.(3)The 16S rRNA gene sequences were annotated using the Greengenes database and Silva database as reference databases,obtaining the OTU tables.And then,the functions of bacterial communities in Xiamen were predicted by three different methods:PICRUSt,Tax4fun,and FAPROTAX.The results predicted by PICRUSt and Tax4Fun method,showed little difference.The overall ranking of the samples in the KEGG orthologous cluster(KO)abundance analysis by cluster analysis was S12>S05>S08>S03>S19>S07,the relative abundance of amino acid metabolism and sulfur metabolism in the KEGG metabolic pathway kept the same ranking.(4)Analysis of the relative abundance of SAR11 bacteria in Xiamen coast and the relative abundance of ABC transporters mapped in the KEGG database has the same rank,indicatd that there was consistency in the composition of bacterial communities and the functions of bacterial communities.In addition,sample S12 preferred the assimilation sulfate reduction while the dissimilation sulfate reduction prevail in sample S19.(5)The use results of FAPROTAX prediction found that the Xiamen coast bacterial communities was mainly concentrated in the functions of autotrophic,heterotrophic,nitrate metabolism,and sulfur metabolism.The relative abundance of the bacteria functions in S07 sample and S12 sample were relatively low,while S05 sample and S19 sample had a relatively high abundance.Since the FAPROTAX method was based on the cultivated bacterial database,the predicted relative abundance trends between samples were different from the other methods.