A novel biosurfactant producing Kocuria rosea ABR6 as potential strain in oil sludge recovery and lubrication.

Biosurfactants are amphiphilic molecules composed of a hydrophilic and hydrophobic moiety and had the ability to penetrate into different phases to reduce the surface tension. This features caused to oil recovery, lubrication and facilities of crude oil in pipeline. In current research Biosurfactant-producing strain was isolated from the storage tanks of the Isfahan Oil Refining Company in Iran, and screened by oil expansion test, droplet collapse, and surface tension reduction measurement. Hydrocarbon recovery from crude 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 using Response Surface Method (RSM). 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. Chemical analysis proved that the produced biosurfactant 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 upgraded as it could be said that for a certain distance the transfer time reduced from 64 to 35 s. The highest biosurfactant production was measured at pH 9, aeration rate of 120 rpm and 96 h 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.