Enhanced Production of Cellulase from Bacillus licheniformis K‐3 with Potential for Saccharification of Rice Straw

Abstract

The unavailability of process‐suitable cellulases and expensive cost prompted research on the economic production of proficient enzymes. Bacillus licheniformis K‐3, an isolate from degrading lignocellulosic biomass, can produce cellulose, possessing activity and stability over broad pH range (4.0–10) and at elevated temperature (40–90 °C). B. licheniformis K‐3 can be used to successfully utilize agricultural residues (such as wheat bran, corn waste, wheat straw, almond hulls, soybean meal, and mustard cake) as substrates for growth and cellulase production. The most effective fermentation variables (wheat bran, incubation time, and medium pH) have been earmarked on the basis of Plackett–Burman designed experiments and they were optimized by using response surface methodology to achieve a 7‐fold enhancement in the cellulase yield. Partially purified cellulase showed efficient saccharification potential for single‐phase sulphuric‐acid‐pretreated rice straw.

Optimization of bioprocess variables for production of a thermostable and wide range pH stable carboxymethyl cellulase from Bacillus subtilis MS 54 under solid state fermentation

“…Huge microbial diversity (fungi and bacteria) especially of extreme ecological niches can be exploited to get enzymes with suitable properties [5]. Most of the commercially available cellulases are of fungal origin [6,7], and relatively fewer bacterial cellulases have been investigated [1][2][3][4][5]8]. Bacteria offer certain discreet advantages over fungi as source of potentially novel enzymes (cellulases) which may have high process suitability [1][2][3]8].…”

“…Maize bran is nutritionally rich substrate that can support adequate growth of bacteria [3]. Process optimization by Design of Experiments (DoE) is an established approach for enhancing productivity, and hence may contribute substantially toward cost reduction for industrial enzyme production [1][2][3]10,14,15,17].…”

Production of poly-β-hydroxybutyrate by Bacillus cereus PS 10 using biphasic-acid-pretreated rice straw

“…However, relatively fewer reports are available on use of lignocellulosic materials for PHB production [14]. Lignocellulosic materials (agricultural/forestry residues) may serve as a cheap and renewable feedstock for production of commercial products [17][18][19][20]. However, these materials being rigid and fibrous in structure require prior processing before these can be converted into fermentable sugars that could be used by microorganisms [25].…”

“…Process optimization by conventional 'one-variable-at-a-time' (OVAT) approach faces several limitations [20], therefore, statistical based experimental designs have gained importance as economic and practical solutions for process optimization for various products including PHB [8,[18][19][20][21]. Rare reports on statistical based optimization of PHB production are available especially using lignocellulosic materials as substrates [9].…”

“…PHB from Gram-positive bacteria may be preferred especially for biomedical of potential inhibitors [17][18][19]. Recently, biphasic SA pretreatment approach has been used in which two stage treatments is done, first stage at relatively mild conditions during which the hemicellulose fraction is hydrolyzed, and a second stage involves acid and/or enzymatic hydrolysis at relatively higher temperatures and/or longer time during which the cellulose is hydrolyzed [18,19]. This approach promises maximum sugar release with less production of inhibitors [18].…”