In situ environment rather than substrate type dictates microbial community structure of biofilms in a cold seep system.

On On Lee,Chun Shum Shek,Feras F Lafi,Guang Chao Wang,Yong Wang,Renmao Tian,Xixiang Zhang,Wei Xu,Zenon B Batang,Weipeng Zhang,Pei-Yuan Qian,Salim Bougouffa,Abdulaziz Al-Suwailem,Vladmir B Bajic

doi:10.1038/srep03587

Abstract

Using microscopic and molecular techniques combined with computational analysis, this study examined the structure and composition of microbial communities in biofilms that formed on different artificial substrates in a brine pool and on a seep vent of a cold seep in the Red Sea to test our hypothesis that initiation of the biofilm formation and spreading mode of microbial structures differs between the cold seep and the other aquatic environments. Biofilms on different substrates at two deployment sites differed morphologically, with the vent biofilms having higher microbial abundance and better structural features than the pool biofilms. Microbes in the pool biofilms were more taxonomically diverse and mainly composed of various sulfate-reducing bacteria whereas the vent biofilms were exclusively dominated by sulfur-oxidizing Thiomicrospira. These results suggest that the redox environments at the deployment sites might have exerted a strong selection on microbes in the biofilms at two sites whereas the types of substrates had limited effects on the biofilm development.

Highlights

In situ environment rather than substrate type dictates microbial community structure of biofilms in a cold seep system
Using microscopic and molecular techniques combined with computational analysis, this study examined the structure and composition of microbial communities in biofilms that formed on different artificial substrates in a brine pool and on a seep vent of a cold seep in the Red Sea to test our hypothesis that initiation of the biofilm formation and spreading mode of microbial structures differs between the cold seep and the other aquatic environments
This was stemmed from the presence of agglomerated masses or clumps on the BP-biofilms developed on the outer polyvinyl chloride (PVC) plates, which were not frequently observed on PS plates

Summary

Introduction

In situ environment rather than substrate type dictates microbial community structure of biofilms in a cold seep system. EPS production by microbes leads to their establishment on the surface, followed by alterations of the microbial physiological responses to conditions in their specific niches and cell-cell interaction[3] These processes can be affected by environmental or external signals that trigger corresponding genetic and regulatory circuits during biofilm development[6] and lead to substantial differences in biofilm structure and composition. We deployed artificial substrates of different materials at a newly-discovered cold brine seep system at about 840–850 m depth on the continental margin of the central Red Sea, the Thuwal Seeps[22], to examine the biofilm development in its brine pool and seeping vent and on different types of substrates, using 16S rDNA tag pyrosequencing, clone library, and scanning electron microscopy

Methods

Results

Conclusion