Title: Removal of Cr (VI) from tannery effluents with mixed cultures of bacteria and fungi isolated from soils contaminated with tropical tannery effluents

Authors: Olubunmi O. Akpomie; Bernard O. Ejechi

Addresses: Department of Microbiology, Delta State University, P.M.B. 1, Abraka, Nigeria ' Department of Microbiology, Delta State University, P.M.B. 1, Abraka, Nigeria

Abstract: Pseudomonas aeruginosa, Escherichia coli, Aspergilllus niger and Penicillium chrysogenum isolated from tannery effluent-contaminated soil showed resistance to chromium [Cr (VI)] with minimum inhibitory concentrations (MIC) of 80-120 mg/l in potato dextrose or nutrient agar. This increased to 100-150 mg/l in glucose and yeast extract supplemented mineral salts medium. Significant removal of Cr (VI) occurred in tannery effluents treated with the isolates singly, although reductions were >0.05 mg/l (stipulated limit) in all treatments. Chromium was reduced in glucose, beef and yeast extracts supplemented effluents to non-detectable levels < 0.05 mg/l in all except in E. coli treatment. However, mixed cultures' treatment of non-supplemented effluent reduced Cr (V1) below 0.05 mg/l with the consortium of P. aeruginosa, P. chysogenum and A. niger reaching 99.6-100% removal. Mixed bacterial and fungal culture may be of potential cost effective application in the removal of chromium in tannery wastes.

Keywords: tannery effluent; chromium removal; Pseudomonas aeruginosa; Escherichia coli; E coli; Aspergilllus niger; Penicillium chrysogenum; bacteria; fungi; soil contamination; environmental pollution; potato dextrose; nutrient agar; glucose; yeast extract; mineral salts; tannery waste.

DOI: 10.1504/IJEWM.2016.076431

International Journal of Environment and Waste Management, 2016 Vol.17 No.1, pp.60 - 70

Received: 22 Sep 2014
Accepted: 01 Jan 2016
Published online: 06 May 2016 *

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