Investigation of Oil-Degrading Bacterial Growth in Salt Solution and Screening of Its Bio-Emulsifiers Production Ability

Abstract

Background:Oil-degrading bacteria could be used for remediation of oil pollution as microbial degradation has a crucial role in oil removal, as well as evaporation and weathering procedure.

Objectives: This study aims to identify some oil-degrading bacterial strains and investigate their growth in salt solution with various concentrations and their ability to produce bio-emulsifiers.

Methodology:16 samples which were collected from sea water of different 4 locations in Egypt at, nearly, 1 meter depth. After bacterial growth and cultivation, the Bushnell Hass medium was made and deposited 10 mL in glass bottles 1 percent, 5 percent, 10 percent, 25 percent, and 50 percent, respectively of crude oil concentrations. 10 mL of basic medium was placed in glass bottles, along with various amounts of saline: 1.2 percent, 2.4 percent, 3.6 percent, and 5percent.For determining the ability of production bio-emulsifiers, bacterial filtration was added to 2 mL of various hydrocarbon compounds in sterile glass for each isolation type (toluene, hexane), and mixed for two minutes at room temperature and left to settle for 24 hours.The optimum emulsification effect was then determined using an equation. Identification of the selected isolates was done by 16S rRNA.

Results:Isolated bacteria had the ability for growing in a crude oil-containing medium with various concentrations up to [50%]. Excellent growth in all samples was detected in site 4. Excellent growth was observed in [34%] of the isolates at a concentration of [1%] and 5% crude oil. Excellent growth was possessed by 87.5% of the isolated bacteriaat the [1.2%] salt concentration, 75% at the [2.4%] concentration, and 75% of the isolated bacteria at the [3.6%] concentration. Isolated bacteria produced bio-emulsifiers on Toulene and Hexane. The identified bacterial isolates wereAcinetobactergrimontii, Aeribacilluspallidus, and Bacillus cereus.

Conclusion: The concentration of crude oil concentration as well as salinity has a crucial role in the oil biodegradation.