Qualitative Assessment of Biosurfactant Producing Microorganisms in the Cleanup of Crude Oil in Soil

Abstract

Crude oil contaminates the soil in several ways and its poisonous effect has caused havoc in the environment which can lead to the death of living organisms. Some microorganisms can produce biosurfactants which aid in high biodegradability. This study investigated biosurfactant production by some indigenous microorganisms isolated from crude oil-contaminated soils. Isolates were identified, preliminarily screened for 7 days using the mineral salt medium on agar plates, and then screened further for biosurfactant production. The Drop collapse test, Haemolytic test and Oil spreading test were used to determine the production of biosurfactants. Thirty microorganisms were isolated from the contaminated soil samples and identified as species of Corynebacterium (7), Bacillus (8), Lysinibacillus fusiformis (1) Aspergillus (3), Penicillium (5), Fusarium (3), Microsporum (2) and Cladosporium (1). Three of the isolates (Bacillus subtilis, Lysinibacillus fusiformis, and Aspergillus flavus) proved to be biosurfactant producers while also utilizing 8 % of crude oil during qualitative screening. These isolates can produce active compounds (biosurfactants) that can emulsify the crude oil which leads to the easy degradation of the crude oil. They could also be potential candidates for Microbial Enhanced Oil Recovery