Author/Authors :
Chhabra، Meenu نويسنده 1Department of Biology, Indian Institute of Technology-Jodhpur, Jodhpur 342011, Rajasthan, India , , Mishra، Saroj نويسنده Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz-Khas, New-Delhi 110016, India , , Ramaswamy Sreekrishnan، Trichur نويسنده Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz-Khas, New-Delhi 110016, India ,
Abstract :
Background: Laccases have good potential as bioremediating agents and can be used continuously in the
immobilized form like many other enzymes.
Methods: In the present study, laccase from Cyathus bulleri was immobilized by entrapment in Poly Vinyl Alcohol
(PVA) beads cross-linked with either nitrate or boric acid. Immobilized laccase was used for dye decolorization in
both batch and continuous mode employing a packed bed column. The products of degradation of dye Acid Red
27 were identified by LC MS/MS analysis.
Results: The method led to very effective (90%) laccase immobilization and also imparted significant stability to
the enzyme (more than 70% after 5 months of storage at 4°C). In batch decolorization, 90-95% decolorization
was achieved of the simulated dye effluent for up to 10–20 cycles. Continuous decolorization in a packed bed
bioreactor led to nearly 90% decolorization for up to 5 days. The immobilized laccase was also effective in
decolorization and degradation of Acid Red 27 in the presence of a mediator. Four products of degradation
were identified by LC-MS/MS analysis.
Conclusions: The immobilized laccase in PVA-nitrate was concluded to be an effective agent in treatment of
textile dye effluents.
