Co-acclimation of bacterial communities under stresses of hydrocarbons with different structures.

Hui Wang,Wenwen Dong,Bin Wang,Xiaoke Hu

doi:10.1038/srep34588

Abstract

Crude oil is a complex mixture of hydrocarbons with different structures; its components vary in bioavailability and toxicity. It is important to understand how bacterial communities response to different hydrocarbons and their co-acclimation in the process of degradation. In this study, microcosms with the addition of structurally different hydrocarbons were setup to investigate the successions of bacterial communities and the interactions between different bacterial taxa. Hydrocarbons were effectively degraded in all microcosms after 40 days. High-throughput sequencing offered a great quantity of data for analyzing successions of bacterial communities. The results indicated that the bacterial communities responded dramatically different to various hydrocarbons. KEGG database and PICRUSt were applied to predict functions of individual bacterial taxa and networks were constructed to analyze co-acclimations between functional bacterial groups. Almost all functional genes catalyzing degradation of different hydrocarbons were predicted in bacterial communities. Most of bacterial taxa were believed to conduct biodegradation processes via interactions with each other. This study addressed a few investigated area of bacterial community responses to structurally different organic pollutants and their co-acclimation and interactions in the process of biodegradation. The study could provide useful information to guide the bioremediation of crude oil pollution.

Highlights

Capable of degrading a small range of hydrocarbons with similar structure, e.g. alkanes with different carbon chain length, or aromatic hydrocarbons with similar characteristics
The results indicated that bacteria in the genera Thalassolituns and Roseobacter dominated the process of n-alkane degradation; bacteria in the genus Alcanivorax were responsible for the degradation of branched alkane, and Cycloclasticus was the dominant genus in PAHs degradation
We successfully revealed successions of bacterial communities and co-acclimation between different functional bacterial taxa under stresses of hydrocarbons with different structures

Summary

Introduction

Capable of degrading a small range of hydrocarbons with similar structure, e.g. alkanes with different carbon chain length, or aromatic hydrocarbons with similar characteristics. Different bacteria dominate specific process of biodegrading hydrocarbons with different structures. Bacterial genus Alcanivorax was regarded as the typical functional group degrading strait-chain or branched alkanes[9,17], while bacteria in the genus Cycloclasticus showed priority in degrading PAHs18,19. A series of microcosms were setup with addition of petroleum hydrocarbons with different structures, to investigate 1, successions of bacterial communities under stresses of different hydrocarbons; 2, functions and contributions of different bacterial taxa in each steps of hydrocarbon-degrading; 3, co-acclimations between different bacterial phylotypes or between different functional groups. This study could provide a better understanding of co-acclimation of functional bacteria in the process of biodegrading hydrocarbons

Methods

Results

Discussion

Conclusion