Molecular ecology of sulphate-reducing bacteria involved in anaerobic degradation of hydrocarbons at marine gas and oil seeps

点击翻译按钮获取中文摘要

Marine gas and oil seeps are hot spots of microbial sulphate reduction because of a long term supply of hydrocarbons to natural microbial communities. In the first funding period members of the diverse deltaproteobacterial Desulfosarcina/Desulfococcus (DSS) group have been shown to be global key players in seep sediments (CARD-FISH) and to be capable of butane and dodecane degradation (DNA-/RNA-SIP). In one part of the proposed project we aim to further enrich the key butane- and dodecane-degrading sulphate-reducing bacteria (SRB) from established enrichment cultures. The n-alkane- degrading microbial community will be further targeted by in situ detection of methylalkyl-succinate synthase genes (masD) via GeneFISH. In another part, SEEP-SRB2, a group of uncultured SRB highly abundant in marine seep sediments, will be studied by a polyphasic approach including enrichment attempts and genomics. Additionally, sequencing of single cell genomes from four other uncultivated SRB will be continued. The combination of comparative genome analysis and proteomics will be used to gain insights into a common gene pool and the expression of novel key enzymes for hydrocarbon degradation. By showing the environmental relevance of enriched SRB and by the in situ quantification of masD and corresponding organisms this project contributes to a better understanding of in situ hydrocarbon turnover and a possible response of the environment to oil spills.