Distribution and diversity of bacterial species with potential of producing biosurfactant from tannery effluents in Maiduguri, Nigeria

Abstract

The search of bacteria with ability to produce biosurfactant is extended to various environments. The potential of bacterial isolates from tannery effluents was considered because of the complex form of organic material released as effluent. These tannery effluents can be a rich source of nutrient to be used by microorganisms. Effluents samples from various points of the tannery production were collected aseptically and transported to the laboratory for possible isolation of bacteria with the ability to produce biosurfactants. Specifically, samples were collected from six different sections of Majema tannery. Physicochemical analysis was conducted on the samples and culture method was used to isolate the bacterial isolates which were screened using hemolysis, oil emulsification drops collapse and oil spreading techniques. The result of physicochemical analysis revealed that the effluents were having slightly low pH (5.3-5.6), EC of (45.0-70.0), BOD (0.76-1.21) and DO of (6.66-7.49). Six bacteria species were isolated by enrichment culture method using Mineral salt media (supplemented with 0.1% v/v Bonny light crude oil) and identified using biochemical characterization; the result showed bacterial species such as Pseudomonas sp., Bacillus sp., Citrobacter sp., Micrococcus sp., Rhodococcus and Corynebacteriuim sp. Further screening of the bacterial isolates for biosurfactant production using Hemolysis, oil emulsification, drop collapse and oil spreading methods showed all the bacterial isolates have been hemolytic and able to emulsify and spread the oil respectively. The isolates are also positive for drop collapse except for Rhodococcus sp. and Corynebacterium sp. This indicates that the bacterial
isolates are very good candidates for the production of biosurfactant and can be used for commercialization.