Optimization of Laccase Production from Bacillus sp. PK4 through Statistical Design of Experiments

Abstract

Statistical design of experiments was employed to optimize the media composition for the production of laccase from Bacillus sp. PK4. In order to find the key ingredients for the best yield of enzyme production from the selected eleven variables viz yeast extract, glucose, zinc sulphate, copper sulphate, potassium chloride, magnesium sulphate, calcium chloride, ferrous sulphate, sodium chloride, potassium dihydrogen phosphate (KH 2 PO 4) and dipotassium hydrogen phosphate (K 2 HPO 4), Plackett-Burman design was applied. The MgSO 4, FeSO 4, and CuSO 4 showed positive estimate, and their concentration optimized further. The steepest ascent method and Box-Behnken method revealed that 1.5 mM MgSO 4, 0.33 g/l FeSO 4 and 1.41 mM CuSO 4 were optimal for the laccase production by Bacillus sp. PK4. This optimization strategy leads to enhancement of laccase production from 2.13 U/ml to 40.79 U/ml. Agro-wastes residues replace the carbon source glucose in the optimized media namely sugarcane bagasse, wheat bran, rice husk, and groundnut shell, among these groundnut shells (117 U/ml) was found to enhance the laccase production significantly. The laccase produced by Bacillus sp. PK4 was found to have the potential to degrade persistent organic pollutant benzo[a]pyrene.

Application of Trametes pubescens for dye removal and biological pretreatment of sugarcane bagasse

“…The positive effects of CuSO 4 on laccase production by Bacillus sp. PK4 were also previously observed by Rajeswari and Bhuvaneswari 31 …”

“…In this study, 41 experimental runs were conducted to evaluate the effects of five different factors including temperature, incubation period, moisture content, particle size and CuSO 4 (Table 1) on the fermentation of bagasse by T. pubescens MB89. Previously, the BBD was used to optimize laccase production, and the optimization strategy enhanced laccase production from 2.13 IU mL −1 to 40.79 IU mL −1 31 . The BBD was also used by Qadir et al 32 .…”

“…Previously, the BBD was used to optimize laccase production, and the optimization strategy enhanced laccase production from 2.13 IU mL −1 to 40.79 IU mL −1 . 31 The BBD was also used by Qadir et al 32 to optimize three factors influencing the fermentation of bagasse by a yeast co-culture and obtained 9.81 IU mL −1 of cellulase. In this study, high-laccase titers were obtained in 1).…”

“…PK4 were also previously observed by Rajeswari and Bhuvaneswari. 31 Cellulase production by N. sedimentimangrovi UE25…”