Background: Microbial degradation of highly stable textile dyes, using lignin peroxidase,
is an eco-friendly, less expensive and much advantageous in comparison to the
Objective: Biodegradation potential of lignin peroxidase (LiP), from Pseudomonas fluorescens
LiP-RL5, was enhanced after optimization and purification so as to use it as a potential
bioresource for the treatment of textile effluent.
Methods: LiP producing bacterial isolate was primarily screened by methylene blue assay
followed by LiP assay. The standard protocol was used for purification of lignin peroxidase
and purified LiP was finally used for degradation of textile dyes.
Results: 57 bacterial isolates were screened for lignin peroxidase activity. Isolate LiP-RL5
showed maximum activity (19.8 ±0.33 %) in terms of methylene blue reduction in comparison
to others. Biochemical and molecular characterization of LiP-RL5 showed 99 % similarity
with P. fluorescens. Lignin peroxidase activity was increased by 50 % after optimization
of cultural conditions. Maximum enhancement in the activity was achieved when peptone
was used as a nitrogen source. LiP from P. fluorescens LiP-RL5 was further purified up to 2
folds. SDS-PAGE analysis revealed a single protein band of approximately 40 kDa. Enzyme
also showed high catalytic efficiency with Km= 6.94 mM and Vmax= 78.74 μmol/ml/min. Purified
enzyme was able to decolorize the simulated textile effluent up to 45.05 ±0.28 % after
Conclusion: High catalytic efficiency of purified LiP from P. fluorescens LiP-RL5 suggests
its utility as a potential candidate for biodegradation of toxic dyes in the industrial effluent,
which could be successfully utilized for wastewater treatment at commercial level.