ABSTRACT
Biodegradation and detoxification of dyes, Malachite green, Nigrosin and Basic fuchsin have been carried out using two fungal isolates Aspergillus niger, and Phanerochaete chrysosporium, isolated from dye effluent soil. Three methods were selected for biodegradation, viz. agar overlay and liquid media methods; stationary and shaking conditions at 25 °C. Aspergillus niger recorded maximum decolorization of the dye Basic fuchsin (81.85%) followed by Nigrosin (77.47%), Malachite green (72.77%) and dye mixture (33.08%) under shaking condition. Whereas, P. chrysosporium recorded decolorization to the maximum with the Nigrosin (90.15%) followed by Basic fuchsin (89.8%), Malachite green (83.25%) and mixture (78.4%). The selected fungal strains performed better under shaking conditions compared to stationary method; moreover the inoculation of fungus also brought the pH of the dye solutions to neutral from acidic. Seed germination bioassay study exhibited that when inoculated dye solutions were used, seed showed germination while uninoculated dyes inhibited germination even after four days of observation. Similarly, microbial growth was also inhibited by uninoculated dyes. The excellent performance of A. niger and P. chrysporium in the biodegradation of textile dyes of different chemical structures suggests and reinforces the potential of these fungi for environmental decontamination.
Subject(s)
Aspergillus niger/metabolism , Biodegradation, Environmental , Biotransformation , Coloring Agents/metabolism , Phanerochaete/metabolism , Soil Microbiology , Aniline Compounds/metabolism , Aspergillus niger/growth & development , Aspergillus niger/isolation & purification , Hydrogen-Ion Concentration , Industrial Waste , Phanerochaete/growth & development , Phanerochaete/isolation & purification , Rosaniline Dyes/metabolism , TemperatureABSTRACT
Binding of penicillin amidase from E. coli 436 to aniline-, benzylamine- and phenylethylamine-Sepharose was studied. Binding of the enzyme to aniline-Sepharose was exclusively due to hydrophobic interactions. Benzylamine-Sepharose binds the enzyme due to affinity interactions in the absence of ammonium sulphate and due to hydrophobic interactions in the presence of ammonium sulphate. A conformational change in the penicillin amidase molecule due to ammonium sulphate there by exposing the side chain binding site as a hydrophobic core is suggested.