ABSTRACT

 Bacterial and fungal growths in radiator fluid were studied. Bacteria isolated from used Abro and Holt fluid were Bacillus sp, Micrococcus sp, serratia sp, Citrobacter sp, Pseudomonas sp, fungi isolated were Aspergillus niger, Rhodotorola sp, Aspergillusflavus.The total bacterial and fungal count in this study was found to be high in the used samples with the range of 8.2x10⁵- 10.9 x 10⁵cfu/ml and 7.0x 10⁵— 8.5 x10⁵cfu/ml respectively for Abro radiator fluid, 10.9x10 — 8.9 x 10⁵cfu/ml and 5.3x 10—55 I05cfu/m! respectively for Holt radiator fluid. Total bacterial and fungal counts for unused radiator fluid ranged 6.5x 10 _6.2 x 103cfu/ml and 4.7 x 10 —4.3 x 10³cfu/ml respectively for Abro radiator fluid and 5.4x 10³— 5.2x 10³ x cfu/ml and 4.3x10 - 4.0 x lO³cfu/ml respectively for Holt. Growth profile of mixed bacterial cultures and fungi were monitored using the optical density, total viable count and pH of the used and unused radiator fluid from the two manufacturers. It was determined that mixed cultures of bacteria and fungi decreased in pH which verified chemical changes of the radiator fluid caused by microbial enzyrnes.lncubation of bacteria at different temperature for 4 hours showed that 100% grew at 30C, 62.5% grew at 45C C, 56% grew at 55C C, 12.5% grew at 60C C while at 70C C there was no growth while at 80C C they were viable but no growth.