Combatting synthetic dye toxicity through exploring the potential of lignin peroxidase from Pseudomonas fluorescence LiP RL5

Abstract

Untreated disposal of toxic synthetic dyes is a serious threat to the environment. Every year, several thousand gallons of dyes are being disposed into the water resources without any sustainable detoxi cation. The accumulation of hazardous dyes in the environment poses a severe threat to the human health, ora, fauna, and micro ora. Therefore, in the present study, a lignin peroxidase enzyme from Pseudomonas uorescence LiP-RL5 has been employed for the maximal detoxi cation of selected commercially used dyes. The enzyme production from the microorganism was enhanced ~ 20 folds using statistical optimization tool response surface methodology. Four different combinations (pH, production time, seed age, and inoculum size) were found to be crucial for the higher production of LiP.The crude enzyme showed decolorization action on commonly used commercial dyes such as Crystal violet, Congo red, Malachite green, and Coomassie brilliant blue. Successful toxicity mitigation of these dyes culminated in the improved seed germination in three plant species, Vigna radiate (20-60%), Cicer arietinum (20-40%), and Phaseolus vulgaris (10-25%). The LiP treated dyes also exhibit reduced bactericidal effects against four common resident microbial species, Escherichia coli (2-10 mm), Bacillus sp. (4-8 mm), Pseudomonas sp. (2-8 mm), and Lactobacillus sp. (2-10 mm). Therefore, apart from the tremendous industrial applications, the LiP from Pseudomonas uorescence LiP-RL5 could be a potential biocatalyst for the detoxi cation of synthetic dyes.