Abstract
At various stages of crude oil refining, solid and semi-solid wastes, known as petroleum sludge, are produced. Accumulation of oil waste in the refinery leads to reduced efficiency of oil refining and its release causes environmental pollution Biosurfactant-producing isolates were isolated from the oil reservoirs of the Isfahan refinery, Iran, and screened by oil expansion test, droplet collapse, and surface tension reduction measurement. Oil recovery from oil sludge was measured under constant conditions. The effect of factoring biosource lubrication on crude oil in pipelines was investigated in vitro. Also, the optimization of biosurfactant production in different conditions was measured as a single factor and Response surface Methodology. The best biosurfactant-producing bacterium was identified as Kocuria rosea ABR6, and its sequence was registered in the gene bank with access number of MK100469 registered. Chemical analysis proved that the biosurfactant produced was a lipopeptide. 7% of crude oil was recovered from petroleum sludge by biosurfactant obtained from Kocuria rosea ABR6.Also, the speed of crude oil transfer in pipelines was reduced from 64 seconds to 35 seconds. The highest biosurfactant production was measured at pH 9, aeration rate of 120 rpm and 96 hours after incubation. The use of biosurfactants produced by Kocuria rosea ABR6 is recommended to remove oil sludge and lubricate oil in pipelines recommended in the oil industry
Biosurfactant Production by Bacillus strains isolated from sugar cane mill wastewaters
