Microbiologically influenced corrosion of maritime platforms

点击翻译按钮获取中文摘要

A considerable amount of research has been performed to determine the effects of destructive biofilms formed on metallic systems, most of which have been in the oil and gas, and energy industries. Although in more recent years there has been an increased interest in an effective means of detecting, monitoring, and preventing corrosion an understanding of the microbial community consortium in association with MIC is still lacking. Consequently, the identities of the bacterial consortia involved in the reactions are not fully known, which can impede the formulation of a targeted mitigation strategy for such issues. To be able to contribute to the future of anti-corrosion strategies of maritime platforms this Ph.D. programme will replicate the polymicrobial community identified at field sites, using culture-independent techniques, to develop an understanding of the bacterial consortia which could form problematic biofilms on maritime platforms for BAE systems. The proposed work will be separated into three stages and the objectives associated with each of these are as follows: Characterise corrosive biofilms found at selected docks, used by BAE systems for maritime platform storage and maintenance, to identify and isolate key microorganisms involved in biofilm activities Construct synthetic laboratory consortia to replicate the different communities identified from maritime platforms Use the synthetic community to define the roles of different bacteria in those biofilms enabling an understanding of how microbiologically influenced corrosion (MIC) associated with them might be controlled Techniques for studying individual microorganisms in the laboratory are well established and advancements in technologies now enable culture-independent characterisation of complex polymicrobial systems at the DNA level, removing the bias of which organisms are easiest to grow in isolation in the laboratory. More recently, progress has been made in several areas of microbiology by combining these two techniques, to construct artificial consortia in the laboratory that can be used to probe the roles of the individual members and to observe how the composition of the consortium changes with time and environmental stresses. Biofilm samples will be taken from sites of interest and total DNA will be prepared and used for barcoded 16S rRNA gene-specific PCR followed by next generation DNA sequencing to determine the bacterial species composition in the biofilms. This information will be used to inform enrichment experiments to isolate representatives of key groups of microorganisms from the biofilm samples. Wherever possible the isolates will correspond to the major players in the original biofilms, though even where this is not possible (because dominant organisms in complex polymicrobial communities in the environment often do not grow easily in laboratory media), representatives of the key functional groups will be obtained. This will allow subsequent experiments with artificially constructed communities of microorganisms in the laboratory, which will allow the effects of various corrosion promoting and corrosion inhibiting microorganisms to be studied in various combinations in a flow cell system that will allow observations to be made by electrochemical methods. The results are expected to inform future anti-corrosion strategies, including use of non-biocidal agents to modify biofilm behaviour and development of functional coatings containing key anticorrosion/ antifouling microorganisms.