Screening of Chromium-reducing Bacteria from Tannery Effluents

Abstract

Tannery effluent has remained one of the major sources of chromium pollution in the environment. Although conventional methods have been widely used, they are inefficient and costly. Bacterial remediation is one of the best alternatives being proposed. Therefore, the aim of this research was to isolate bacteria from tannery effluents and screen them for chromium-reduction potentials. Three different tannery effluents were collected and used for the isolation of chromium-reducing bacteria. The organisms were identified using morphological and biochemical characteristics and screened on 1% (v/v) Cr (VI). The results revealed the presence of three bacterial species, namely: Bacillus subtilis, Escherichia coli and Pseudomonas sp. The screening results revealed that out of the three bacterial isolates, Bacillus subtilis had the highest reduction potential (86.23%), while equal reduction capacity was recorded in both E. coli and Pseudomonas sp. (84.03%). Therefore, these three isolates can be used as a consortium to improve biological remediation of Cr (VI) effluents.