Optimization of different culture conditions for enhanced laccase production and its purification from Tricholoma giganteum AGHP

Abstract

Background:In current times, enzyme-catalyzed reactions have gained importance for the development of new chemical processes. These require the production of large quantity of enzyme at low cost. Solid-state fermentation (SSF) is an efficient process because this bioprocess has a potential to convert agro-industrial residues into valuable compounds. Hence, the current study focuses on the optimization of process parameters for the higher production of laccase using a novel basidiomycete fungi Tricholoma giganteum AGHP under solid-state fermentation (SSF). Further, the purification of laccase using column chromatographic technique was performed.Results: Various physico-chemical parameters were evaluated and maximum production obtained was 2.69 × 10 5 U/g using wheat straw as a dry substrate. Optimum pH was found to be 5.0 and the temperature of 30 °C with 0.3 mM copper as an inducer. The enzyme was purified from the initial protein preparation by two-step column chromatography. A yield of 10.49 % with 3.33-fold purification was obtained using Sephadex G-75 gel permeation chromatography. Further increase in purification (total) was found to be 10.80-fold with a yield of 8.50 % using DEAE Sephadex A-50 ion exchange column chromatography. The purified enzyme was identified as a monomeric protein with a molecular weight of 66 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Conclusion:In view of the results obtained, we can conclude that the extracellular laccase production is governed by various cultural parameters such as pH, temperature, and the composition of culture medium. "One-factor-ata-time" methodology was capable of establishing the optimum conditions that significantly increases the enzyme production several folds using lignocellulosic substrate. Therefore, laccase from T. giganteum AGHP has a potential in several industrial applications.

Lignin Degradation by Fungal Pretreatment: A Review

“…Production of lignolytic gene is influenced by the initial pH of the medium. In the pH of 4 to 5 most of the white rot fungi can grow properly and also the substrate acidity decrease their growth [66]. Inoculum concentration performs a significant function in biological pre-treatment.…”

Induction of laccase in fungus, Cyathus stercoreus using some aromatic inducers

“…A few studies have shown that there was production enhancement by the addition of phenolic and nonphenolic inducers. The maximum production was observed on the 12 th day with a further decline in the production after day 15 with ST02 strain (Patel and Gupte 2016). Mazumder et al (Mazumder et al, 2009) observed that Pleurotus ostreatus have strong proteolytic activity in submerged fermentation (SmF) presumably caused subsequent laccase degradation, which lowered the ultimate laccase production in SmF compared to SSF.…”

Optimization of laccase production and its application in delignification of biomass

“…The different types of substrates have a notable effect on the production of laccase. The wheat straw substrate was also observed as most suitable for laccase production by T. giganteum AGHP with full colonization of substrate on the 16th day of incubation (Patel and Gupte 2016).…”

“…Some of the agricultural waste residues commonly used includes banana peel, apple pomace, brewery waste, wheat straw, wheat bran, rice straw, rice bran, sugarcane bagasse, etc. (Gassara et al 2011;Vivekanand et al 2011;Karp et al 2015;Patel and Gupte 2016). SSF can be applied for the synthesis of several valuable chemical intermediates with many advantages which includes enhanced fungal growth on the contact substrate in moist environment, higher biomass yields, higher product concentration, low energy requirements, less capital investment, less waste generation, simple equipment design and high product recovery (Bagewadi et al 2016a;Viniegra-González et al 2003).…”