Mechanism of Microbiological Contamina- Tion of Jet Fuel and Development of Tech- Niques for Detection of Microbiological Contamination

摘要

Progress was made in understanding and partially solving the problem of jet fuel contaminants, including microorganisms, surface-active materials, iron rust, water, and extraneous materials as they pertain to fuel properties, sludge formation, and the corrosion and degradation of materials in aircraft fuel systems. A study of the corrosion in simulated water bottoms revealed that ions, such as iron and calcium, cause aluminum corrosion. Other ions in the media, such as nitrate and phosphate, prevented aluminum corrosion. Aluminum corrosion was also caused by another mechanism as revealed by the corrosion produced by the growth of fuel isolates in media containing protein, peptides, and amino acids. This type of corrosion was not inhibited by nitrate. Metabolic mechanisms which operate in the production of fuel contaminants such as emulsions and sludges were also studied. Compounds produced by microorganisms grown in fuel were isolated and partially characterized. An effective method of controlling the microorganisms in fuel was discovered. The respiration and viability of these isolates were especially sensitive to inhibition by short-chain unsaturated hydrocarbons. The breakdown of coatings on aluminum was correlated with microbial growth. Microorganisms utilized these coating materials as sources of nitrogen and carbon for growth. Several different detector systems were applied to the study of fuel contamination and corrosion.