USE OF QUANTITATIVE PCR TO MONITOR MICROBIALLYINFLUENCEDCORROSION IN GAS PIPELINES

摘要

Quantitative PCR (qPCR) methods were developed to detect and quantify total bacteria andrnsome critical sub-populations related to gas and oil pipeline corrosion. 16S rRNA genes wererntargeted for the detection and quantification of total bacteria, while other functional genes,rndissimilatory sulfite reductase gene (dsrAB), nitrite reductase gene (nirS), and methyl-coenzymernM reductase gene (mcrA), were targeted for sulfate reducing bacteria (SRB), denitrifyingrnbacteria, and methanognes, respectively. The methods were evaluated in the growth cultures ofrnpipeline samples for accuracy and sensitivity, and then applied directly to pipeline samples. Thernspiking tests indicated our qPCR methods can accurately quantify all four target microorganismsrnwith an accuracy of ±10% of their true value (95% confidence level). The assay sensitivitiesrnwere 2.7 × 103, 20, 13, and 100 gene copies per reaction for bacteria, SRB, denitrifying bacteria,rnand methanogens, respectively. The quantification results indicated that methanogens were morernabundant in most of pipeline samples than denitrifying bacteria, and SRB the least abundantrnbacteria tested in this study. The results also showed the dramatic changes of microbialrncommunity composition after inoculating the pipeline samples to the growth media. The studyrnindicated that functional gene-based quantitative PCR is a fast, accurate, and sensitive method,rnand can be successfully applied to elucidate the distribution, abundance, and functionalrninteractions of microbial communities in various environments.