Process optimization of xylanase production using cheap solid substrate by Trichoderma reesei SAF3 and study on the alteration of behavioral properties of enzyme obtained from SSF and SmF

Abstract

This study aimed to assess the variability in respect of titer and properties of xylanase from Trichoderma reesei SAF3 under both solid-state and submerged fermentation. SSF was initially optimized with different agro-residues and among them wheat bran was found to be the best substrate that favored maximum xylanase production of 219 U (gws)(-1) at 96 h of incubation. The mycelial stage of the fungi and intracellular accumulation of Ca(++) and Mg(++) induced maximum enzyme synthesis. Inoculum level of 10 × 10(6) spores 5 g(-1) of dry solid substrate and water activity of 0.6 were found to be optimum for xylanase production under SSF. Further optimization was made using a Box-Behnken design under response surface methodology. The optimal cultivation conditions predicted from canonical analysis of this model were incubation time (A) = 96-99 h, inoculum concentration (B) = 10 × 10(6) spores 5 g(-1) of dry substrate, solid substrate concentration (C) = 10-12 g flask(-1), initial moisture level (D) = 10 mL flask(-1) (equivalent to a(w) = 0.55) and the level of xylanase was 299.7 U (gws)(-1). Subsequent verification of these levels agreed (97 % similar) with model predictions. Maximum amount of xylanase was recovered with water (6:1, v/w) and under shaking condition (125 rpm). Purified xylanase from SSF showed better stability in salt and pH, was catalytically and thermodynamically more efficient over enzyme from SmF, though molecular weight of both enzymes was identical (53.8 kDa).

Production of cellulolytic enzymes from ascomycetes: Comparison of solid state and submerged fermentation

“…It has also been shown that sterilized WB induced higher ␤-glucosidase activity for A. saccharolyticus compared to pretreated corn stover [56]. In several cases WB has been reported as the substrate that yields the highest enzyme activities of both xylanases and cellulases for many ascomycetes, compared to other lignocellulosic wastes [66][67][68][69]. For instance, A. niger (BC-1) grown on WB in solid state settings had an endoglucanase activity of 48.22 U/gs, which was the highest by a margin of 6.36 U/gs compared to other substrates.…”

Production efficiency versus thermostability of (hemi)cellulolytic enzymatic cocktails from different cultivation systems

“…Therefore, an additional important characteristic of (hemi) cellulolytic enzymes is that they should be stable in the presence of the phenolic compounds that can cause enzyme inhibition and deactivation [23,24]. Previous studies have reported differences in the characteristics of enzymes produced using SSF and SmF, in terms of optimal pH and temperature, thermal stability, kinetic parameters, and size [39,40]. The present work adds to this knowledge by demonstrating that the endoglucanases and ␤-glucosidases produced under SSF were less prone to deactivation by the phenolics in the medium, since greater thermostability was observed in the presence of higher concentrations of these compounds.…”

Dual application of agricultural residues for xylanase production and dye removal through solid state fermentation

“…Soya oil cake was observed to be the best substrate for xylanase production. Various other agro-residues such rice bran, coconut coir pith, dry banana leaves, tea exhausts (Kar et al, 2013), cantaloupe, orange peel, banana peel, watermelon rinds (Mohammed et al, 2013) and Jatropha curcas seed-cake (Ncube et al, 2012) have been investigated as substrates for enzyme production.…”