Effect of industrial tannery effluent on soil fungi and fungal protease/cellulase activity on modified rice husk /modified sawdust medium (MRHM/MSDM)

Abstract

The release of unprecedented tannery effluents into agricultural fields constitutes danger to land fill and nutrient cycling as well as organic matter processing. In the present study, tannery effluent discharged soil (polluted landfill), undischarged soil (control) and effluent discharged (waste) were collected from the surrounding areas of tannery industry. The physico-chemical and biological properties and soil protease / cellulose were examined. The study shows that the value obtained from the colour, odour, pH, electrical conductivity and water holding capacity of the polluted soil was black, foul odour, 5.12, 0.72 µMhos cm-1 and 0.51 mg/l, respectively. In chemical parameters, organic matter, total nitrogen phosphorus and potassium have the following values: 8.2, 1.2, 0.15 and 0.39% respectively. In all ramifications, the polluted soils showed higher values than the control except that of potassium. The soil protease/ cellulose activities of the selected fungal were observed on different media (modified rice husk, modified saw dust and on control liquid media respectively). The activities were found to be higher on MRHM and MSDM (2.81 and 1.82 IU/ml) at maximum of 45 days than the control liquid media (1.23 IU/ml) at maximum of 15 days; they decreased to 0.312 IU/ml at 30 days. It was found that Rhizopus nigricans exhibited the highest cellulase activity (2.81 IU/ml) followed by Aspergillus niger (1.82 IU/ml) and the least Penicillium species (0.98 UI/ml) respectively. Key words: Protease/Cellulase, Rhizopus, Aspergillus, Penicillium solid state/submerge fermentation, tannery waste and contaminated soil.