Optimization and scale-up of laccase production by Bacillus sp. BAB-4151 isolated from the waste of the soap industry

Abstract

Laccase is also known as the blue copper oxidase enzyme. Owing to its ability to oxidizes a wide variety of phenolic and non-phenolic substrates, this enzyme has many biotechnological applications. It is produced by plants, fungi, and a wide variety of bacteria. However, bacterial laccases have been studied more due to their merits over other sources. Production of bacterial laccase at the commercial level demands high yielding cultures and optimization of physicochemical parameters for more yields in a shorter period. Hence, the present research was aimed to isolate the potent laccase producing bacteria and to optimize cultural conditions for higher production of laccase. In this study, six laccase positive bacterial cultures were isolated from the waste of the soap industry in Kadi, Gujarat, India. One isolate later identified as Bacillus sp. BAB-4151 produced copious amounts of laccase. The production process of laccase was optimized at shake flask level by using one variable at a time (OVAT) method and scaled-up to 5 L capacity bioreactor. The isolate produced a higher yield of laccase under diverse physicochemical and nutritional conditions. The OVAT approach resulted in 2.9 folds improvement in the yield of laccase, which further increased by 1.4 fold during scale-up at a laboratory-scale bioreactor. The ability of the organism to produce laccase over of range of physico-chemical conditions and to retain the productivity during scale up of the process at bioreactor level suggests that the organism can be of great commercial significance.