Abstract

MICROBIAL CONTAMINATION OF STORED DIESEL OIL IN NIGERIA

S.C. Onuorah¹, *M.N. Ikegbunam², S.N, Awah¹, and J.O Ezeadila¹

ABSTRACT

The microbial contamination of stored diesel oil in Nigeria was studied. Mineral salts of medium were used for the isolation of the organisms. Seven genera of bacteria were isolated from the sample which were characterized and identified as Micrococcus, Flavobacterium, Acinetobacter, Serratia, Pedioccoccus, Pseudomonas and Bacillus. In addition, five genera of fungi were recovered from the oil and were characterized and identified as Mucor, Fusarium, Penicillium, Rhizopus and Microsporum. The ability of the bacterial isolates to grow in the stored diesel oil was determined by growing them individually for fourteen days in mineral salts medium with the sample as the sole carbon source. The genera Acinetobacter, Serratia Pediococcus and Pseudomonas produced heavy turbidity while Micrococcus, Flavobacterium and Bacillus produced moderate turbidity while growing in the medium. These organisms may contribute to aging instability in diesel oil, induce the corrosion of storage tanks and pipe works, form mats which can block filters and pipelines and increase wear in fuel pumps. These problems can be drastically minimized by incorporating effective biocides into the oil as well as frequent removal of water from the fuel tanks. In addition, the holding of strategic reserves for long periods should be discouraged.

Keywords: Mucor, Fusarium, Penicillium, Rhizopus and Microsporum.