Bioremediation of motor oil-contaminated soil and water by a novel indigenous Pseudomonas otitidis strain DU13 and characterization of its biosurfactant.

Production of biosurfactant by a novel indigenous isolate Pseudomonas otitidis strain DU13 and its role in bioremediation of petroleum hydrocarbon is reported. The identity of the isolate was confirmed by 16S rDNA gene sequencing analysis (Genbank accession: MK177190). The biosurfactant produced by the isolate could reduce the surface tension of petroleum supplemented medium by 46% just after 7 days of treatment. The emulsification index (E 24 ) of the surfactant was found 37, 35, and 20%, respectively, against used motor oil, diesel, and kerosene. The FTIR spectrum of the crude biosurfactant showed the presence of υC-H stretch, υCH2, υ-C=C stretch and υC-H bonding. The isolated strain could degrade 26% of TPH content of used motor oil in liquid culture. Whereas, ex situ pilot-scale field trial demonstrated very high bioremediation potential of the isolate in terms of germination rate of Vigna radiata and Cicer arietinum seeds and plant growth just after 20 days of treatment. © King Abdulaziz City for Science and Technology 2022.