Extracellular bacterial laccase based biodegradation of Remazol Brilliant Blue R and phytotoxicity studies

Abstract

Laccase producing bacteria, Pseudomonas putida LUA15.1 was isolated from rice rhizospheric soil samples of paddy fields of Una district, Himachal Pradesh (India). Remazol Brilliant Blue R (40 mg/l) was 90.21% decolorized within 48 hrs by Pseudomonas putida LUA15.1. Purification of laccase enzyme was done by using ammonium sulfate precipitation, dialysis, gel filtration chromatography and ion exchange chromatography and 94.02% decolorization of Remazol Brilliant Blue R (40 mg/l) was observed by purified laccase of Pseudomonas putida LUA15.1. UV-Visible absorption spectrum showed the decolorization of Remazol Brilliant Blue R and phytotoxicity studies revealed the degradation of Remazol Brilliant Blue R into non-toxic products by purified laccase of Pseudomonas putida LUA15.1. Seed germination, length of plumule and radicle of Phaseolus vulgaris were significantly affected by Remazol Brilliant Blue R than its degradative metabolites indicating less toxic nature of degradation metabolites as compared to dye. It was therefore concluded that Pseudomonas putida LUA15.1 and its extracellular laccase has a good potential for use in the treatment of industrial effluent containing Remazol Brilliant Blue R.