Regional variations in the diversity and predicted metabolic potential of benthic prokaryotes in coastal northern Zhejiang, East China Sea.

Huajun Zhang,Heping Chen,Lian Liu,Kai Wang,Xiansen Ye,Demin Zhang

doi:10.1038/srep38709

Abstract

Knowledge about the drivers of benthic prokaryotic diversity and metabolic potential in interconnected coastal sediments at regional scales is limited. We collected surface sediments across six zones covering ~200 km in coastal northern Zhejiang, East China Sea and combined 16 S rRNA gene sequencing, community-level metabolic prediction, and sediment physicochemical measurements to investigate variations in prokaryotic diversity and metabolic gene composition with geographic distance and under local environmental conditions. Geographic distance was the most influential factor in prokaryotic β-diversity compared with major environmental drivers, including temperature, sediment texture, acid-volatile sulfide, and water depth, but a large unexplained variation in community composition suggested the potential effects of unmeasured abiotic/biotic factors and stochastic processes. Moreover, prokaryotic assemblages showed a biogeographic provincialism across the zones. The predicted metabolic gene composition similarly shifted as taxonomic composition did. Acid-volatile sulfide was strongly correlated with variation in metabolic gene composition. The enrichments in the relative abundance of sulfate-reducing bacteria and genes relevant with dissimilatory sulfate reduction were observed and predicted, respectively, in the Yushan area. These results provide insights into the relative importance of geographic distance and environmental condition in driving benthic prokaryotic diversity in coastal areas and predict specific biogeochemically-relevant genes for future studies.

Highlights

Knowledge about the drivers of benthic prokaryotic diversity and metabolic potential in interconnected coastal sediments at regional scales is limited
The diversity of benthic prokaryotes has been investigated across various coastal marine ecosystems[4,5,6,7,8,9], demonstrating a wide range of environmental drivers shaping benthic prokaryotic communities such as sediment depth[10], water depth[11], temperature[12], ocean currents[5], sediment texture[8], salinity[6], nutrients[13], organic matter quantity and availability[14], heavy metals and organic pollutants[7]
Previous studies have suggested that geographic distance drives variation in benthic prokaryotic communities[15,16]

Summary

Introduction

Knowledge about the drivers of benthic prokaryotic diversity and metabolic potential in interconnected coastal sediments at regional scales is limited. The enrichments in the relative abundance of sulfate-reducing bacteria and genes relevant with dissimilatory sulfate reduction were observed and predicted, respectively, in the Yushan area These results provide insights into the relative importance of geographic distance and environmental condition in driving benthic prokaryotic diversity in coastal areas and predict specific biogeochemically-relevant genes for future studies. Knowledge about the drivers of prokaryotic diversity in interconnected coastal sediments at a regional scale is still limited Such information may be beneficial for understanding the relative importance of geographic distance and local environmental condition in shaping the diversity of benthic prokaryotes in coastal ecosystems. We used 16S rRNA gene sequencing and PICRUSt functional prediction to investigate regional variations in the diversity and metabolic functional potential of prokaryotic communities in the surface sediments from above coastal zones to answer three questions: (1) Does geographic distance overwhelm local environmental condition in shaping prokaryotic β-diversity? We used 16S rRNA gene sequencing and PICRUSt functional prediction to investigate regional variations in the diversity and metabolic functional potential of prokaryotic communities in the surface sediments from above coastal zones to answer three questions: (1) Does geographic distance overwhelm local environmental condition in shaping prokaryotic β-diversity? (2) Do prokaryotic assemblages show biogeographic provincialism across the zones? (3) How does the predicted metabolic potential of prokaryotes shift across the coastal zones?

Methods

Discussion

Conclusion