Microbial Bioremediation of Effluents from Tanning Industry in Bangladesh

• Extensive use of chromium, cadmium and lead nitrate in tanning industry has caused substantial environmental pollution in Bangladesh. Bioremediation of tanning effluents with the help of bacteria was investigated. Samples of effluents with cadmium, chromium and lead nitrate (10mg/ml) were incubated in mineral salt medium at 37°C for 4 days and bacterial strain was isolated from the sample. Preliminary characterization of the organisms according to Bergey's manual suggests that the organisms may belong to Coccus species. The rate of reduction of these effluents was determined by using the flame Atomic Absorption Spectrophotometer (AAS). Out of 3 ppm concentration the rates of reduction were found to be 2.96 ppm for chromium; 2.92 ppm for cadmium and 2.46 ppm for lead nitrate. The isolated bacteria harboured three endogenous plasmids. All of the plasmids were lost when the organisms were treated with ethidium bromide (100mg/ml). Loss of the plasmids resulted in disability of the bacteria to grow on media containing chromium, cadmium and lead-nitrate. Phenotypic testing of wild type and cured strains revealed that the gene(s) responsible for chromium, cadmium and lead-nitrate degradation may reside upon the plasmids.

Nyckelord

Effluents

Bacteria

Plasmid

Bioremediation

Naturvetenskap

Natural sciences

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)