Hydrocarbon Fuel will always have Microbial infection. It is a serious threat to Marine Safety and responsible for extensive damage to marine, industrial and land transport machinery.

The cost attributable to microbiological contamination of diesel fuel and hydrocarbon oils is immense and cannot be quantified.
Bacteria of a variety of types, both aerobic and anaerobic, produce organic acids, including sulphurous and sulphuric. These highly corrosive chemicals will cause severe degradation of storage tank coatings, corrosion of metal tank surfaces and injection equipment.

Microbiological contaminant impairs performance and dramatically increases wear rates of injectors. It also brings about poor combustion conditions, loss of engine power and reduced service life of components.

Microbiological bacteria causes fuel filter blockage through the growth of bacteria farms in the fuel filter medium. The bacteria colonies passing from the contaminated fuel tank are trapped by the filter element and create an improved environment for bacteria growth within the fuel. The growth accelerates due to the colony's ability to attract more bacteria passing from the tank together with the ability to utilize the nutrient and moisture contained in the fuel. This results in increase in flow resistance and pressure drop across the filter, producing fuel depravation and engine performance.

Treatment through addition of a suitable biocide brings with it its own problems like:

1. The proprietary brands of biocide are expensive.
2. The biocide may kill of some of the bacteria strain, leaving others to enjoy an increase in growth rate and assume the ecological elevation previously prevented by bacteria strains now killed off.
3. If the biocide is highly toxic, it requires special procedures and extreme care in handling.