Isolation and Characterization of Halogenated Aniline-Metabolizing Bacteria from Selected Contaminated Sites in Lagos State, Nigeria

Tobun, Olukemi A.; Adebusoye, Sunday A.; Ilori, Matthew O.

doi:10.21608/eajbsg.2024.390513

Isolation and Characterization of Halogenated Aniline-Metabolizing Bacteria from Selected Contaminated Sites in Lagos State, Nigeria

Document Type : Original Article

Authors

Department of Microbiology, Faculty of Science, University of Lagos, Akoka, Lagos State, Nigeria

10.21608/eajbsg.2024.390513

Abstract

Studies have shown that halogenated aniline (HA) contaminants are released into the environments as a result of numerous human activities. This study aimed to unveil the presence of HA bacterial-metabolizing strains from indigenous polluted sites and their degradation potentials on HA contaminant. Soil samples were collected from three contaminated sites (agricultural site ASS, municipal waste MSS and industrial site ISS). Promising bacterial strains capable of utilizing HAs (3-chloroanilines, 4-chloroanilines, 3-chloro-4-fluoroanilines, and 3, 4-dichloroanilines) were isolated by selective enrichment culture technique. The isolates were characterized based on cultural, biochemical characteristics and 16S rRNA gene sequencing methods. In the present study, Pseudomonas hibiscicola BT9, P. hibiscicola BT7, Stenotrophomonas maltophilia BT8, S. maltoplhilia BT10, Bacillus subtilis WT5 and Alkalihalobacillus halodurans BT2 were isolated from contaminated soil sites by enrichment culture containing equivalent amounts of HAs. Growths of strains BT9, BT7 and BT10 were defined in all the incubation system by increased in biomass, residual substrate concentration and stoichiometric chloride released into the culture media during mineralization. However, lower substrate concentration in strain BT9 was obtained when grew on 3,4-dichloroanilines yielding 65% degradation in 120 h, degradation rate of 0.54 mg L^-1 h^-1 with stoichiometric chloride release of 1.63 mM. Although strain BT10 appeared to utilize the congener in a similar trend, strain BT9 is more amenable to degradation. This study demonstrated that halogenated anilines utilizing bacteria could be used as potential bioremediation agent for cleaning up this contaminant.

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