Molecular Docking of Laccase Protein from Bacillus Safensis DSKK5 Isolated from Earthworm gut: A Novel Method to Study dye Decolorization Potential

摘要

The bacterial communities in the intestinal tracts of earthworm were isolated by culture-dependent approaches. In total, 72 cultures were isolated and purified from the gut of an earthworm under aerobic culture condition, out of which 25 isolates were laccase positive. Isolate 33, a good laccase producer was identified as Bacillus safensis DSKK5, using both biochemical and molecular approaches. It was found to produce maximum laccase activity at 0.75 % of wheat bran, 37 ℃, and pH 6.2. Further, copper sulfate and copper chloride showed a maximum laccase production. In order to understand the affinity of binding and interaction between toxic dyes and bacterial laccase, homology models were generated. The resulted models were further validated and used for docking studies with commonly used industrial dyes. Molecular docking using CCDC GOLD software gave a good score with all the textile dyes. Further, validation using molsoft ICM software showed a good binding energy of -104.25, -106.00, -113.98, and -100.36, with commercial dyes, i.e., procion blue, procion green, procion red, and reactive yellow 86, respectively. Experimental data showed a maximum decolorization with procion green (85.66 %) and procion red (85.58 %), which validate the molsoft ICM results, i.e., -106.00 and -113.98, respectively.