Proteomic Sample Preparation for the Petroleum Industry: A Biocorrosion Case Study

Petroleum-associated environments are among the most chemically complex and biologically extreme systems encountered in the field of industrial biotechnology. Here, microbial activity plays a pivotal role in hydrocarbon biodegradation, reservoir souring, and microbiologically influenced corrosion (MIC). In these systems, proteins constitute the functional interface between microbial metabolism and physicochemical processes affecting infrastructure integrity and environmental impact. This chapter presents an integrated proteomics-based workflow for the characterization of microbial communities inhabiting oil pipeline sludges, with particular emphasis on sample preparation strategies tailored to hydrocarbon-rich, metal-laden, and saline matrices. Optimized phenol-based extraction, electrochemical in vitro corrosion assays, two-dimensional gel electrophoresis, and high-resolution mass spectrometry are combined with metagenomic information to enable robust identification and functional interpretation of proteins involved in redox metabolism, biofilm formation, extracellular electron transfer, sulfur and nitrogen cycling, and stress adaptation. The approach is illustrated through a biocorrosion case study of marine pipeline sludge, revealing key enzymatic systems, including oxidoreductases, hydrolases, cytochromes, ABC transporters, and biofilm-associated structural proteins that mediate metal dissolution and microbial energy conservation. By integrating proteomics with electrochemical measurements and systems-level analysis, this chapter highlights how tailored sample preparation and functional protein profiling can overcome the limitations of culture-dependent methods, providing mechanistic insight into complex petroleum microbiomes. These advances establish proteomics as a critical tool for monitoring, predicting, and ultimately mitigating biocorrosion, as well as for guiding the development of biotechnology-based strategies in the oil and gas industry.