Enhancement of Laccase Production by Optimizing the Cultural Conditions for Pleurotus sajor-caju in Solid-State Fermentation

Shradhdha Sharma,Duggirala Srinivas Murty

doi:10.22207/jpam.15.2.54

Abstract

Nowadays, a lot of interest has been given to the development of cost-effective and efficient enzyme production technologies. Laccase enzymes are widely used in biotechnological, environmental and industrial sectors. Due to the cost-effectiveness of the solid-state fermentation (SSF) process, it is widely used to produce a broad range of biological products. In this study, optimization of moisture content, temperature, pH, and inoculum size were studied to enhance laccase production ability of Pleurotus sajor-caju in SSF by using One Factor At Time (OFAT) and Response Surface Methodology (RSM). OFAT was used as a baseline study for deducing the experimental design of RSM. The highest production of laccase enzyme (1450 U/g) by Pleurotus sajor-caju on wheat straw was observed at 26°C, 6.0 pH, 72.5 % moisture content, 7.5% inoculum size, 1% fructose and 0.5 % peptone. Unlike the conventional inoculum preparation method, here the inoculum was generated by the spawning method for SSF. The molecular weight of partially purified laccase from Pleurotus sajor-caju was estimated to be around 62 K Da using SDS PAGE. The activity staining of laccase was observed as a zymogram on Native PAGE using ABTS as a substrate. Lignin degradation of wheat straw and its structural disruption due to laccase was observed by Scanning Electron Microscopy (SEM).

Highlights

The use of agro-industrial wastes for solid-state fermentation (SSF) is a better option than burning it
This study focused on laccase production using Pleurotus sajor-caju on wheat straw and optimization of different factors for enhancing laccase production in solid state fermentation
This study explored the ability of Pleurotus sajor-caju in solid state fermentation for laccase production using cost effective and available agro-residues

Summary

INTRODUCTION

The use of agro-industrial wastes for solid-state fermentation (SSF) is a better option than burning it. Agricultural residues containing lignin, hemicellulose, and cellulose are abundantly available and cost-effective in SSF32. Presence of carbon and nitrogen sources is the most important criteria for cost effective production in solid state fermentation. Basidiomyceteous fungi, especially white rot fungi widely are used in the production of ligninolytic enzymes like laccase (EC 1.10.3.2)[42], lignin peroxidase The optimization and production of laccase has been shown using white rot fungi[6,16,5,23,39] but to our knowledge, there have been no studies on optimization of laccase production from Pleurotus sajor-caju in solid state fermentation on wheat straw. This study focused on laccase production using Pleurotus sajor-caju on wheat straw and optimization of different factors for enhancing laccase production in solid state fermentation

MATERIALS AND METHOD Culture collection and maintenance

AND DISCUSSION Substrate screening

Findings

CONCLUSION