Screening of Bacteria Isolated from Hydrocarbon Contaminated Soil for Biosurfactant Production within Sokoto Metropolis

Abstract

Biosurfactants are biomolecules with versatile functions that have wide range of applications ranging from pharmaceutical, cosmetic and environmental bioactive compound that has a lot of potentials in bioremediation of oil contaminants. This study was carried out to screen bacteria isolated from hydrocarbon contaminated soil for biosurfactant production in Sokoto metropolis, Sokoto State, Nigeria. The best bacteria for biosurfactant production were detected using standard procedures. The result of physical and chemical characteristics of the hydrocarbon contaminated soil samples from this study revealed that the pH of all soil samples ranges from 4.6- 7.4. The average temperature was 28.5°C to 30°C during winter period. The bacterial count of all samples ranges from 1.0 × 10⁵ ± 0.8 to 2.8 × 10⁵± 2.0 cfu/g. A total of six (6) bacterial genera were identified biochemically as Brucella intermedia, Bacillus sp, Staphylococcus aureus, Proteus mirabilis, Staphylococcus saccharolyticus and Bacillus alvei. And were all positive for biosurfactant screening tests. The best isolates for biosurfactant production were identified molecularly as Brucella intermedia Strain B13 with accession no. MZ571907.1 and Bacillus sp. strain nsu-44 with accession no. OR392926.1. The phylogenetic tree was produced using neighbour joining method based on the close members from GenBank of NCBI. Brucella intermedia and Bacillus sp. which appeared to be the most potent isolates from this study can be applied in large scale production of biosurfactant for different applications.

Keywords: Screening, Bacteria, Hydrocarbon Contaminated Soil, Biosurfactant, Drop Collapse, Oil Displacement