Cost-Effective Production and Optimization of Alkaline Xylanase by Indigenous Bacillus mojavensis AG137 Fermented on Agricultural Waste

Abstract

A xylanase producer Bacillus mojavensis strain, called AG137, isolated from cotton farm (Kashan-Iran). The optimal xylanase activity reached at 55°C & pH 9.0. Enzyme yield was studied using a medium with different agricultural wastes as inducers. Xylanase production of about 249.308 IU/mL was achieved at pH 8 and 37°C, within 48 h submerged fermentation in enzyme production medium supplemented with 2% (w/v) oat bran as an optimum carbon source. A mixture of 1% (w/v) yeast extract and 1% (w/v) tryptone as optimum nitrogen sources, agitation speed 200 rpm, and inoculum size 2% (v/v) were the optimums for maximum production. Accordingly, xylanase yield from 194.68 IU/mL under non-optimized fermentation condition enhanced to 302.466 IU/mL in optimized condition. Screened xylanase is thermostable, presenting 70% stability at 60°C during 30 min. Further enzyme incubation in higher temperature caused a decrease in the residual enzyme activity, yet it retained 68%–50% of its activity after 1 hour from 45°C to 55°C. Besides, it is stable in pH 9 and 10, maintaining over 70% of its activity for 2 h. The enzyme also could preserve 71% and 63% of its initial activity after 3 hours of pre-incubation in the same alkaline condition. Produced xylanase therefore was introduced as an alkaline-active and stable one, displaying suitable thermostability feature, confirmed by HPLC analysis. Hence, all xylanase properties highlight its promising uses in industrial scale.

Optimization of Process Conditions for the Production of Holocellulase by a <i>Bacillus</i> Species Isolated from Nahoon Beach Sediments

“…Similar finding to this study was made by other authors who reported 30°C as optimal temperature for xylanase and cellulase production by different Bacillus species (Nagar et al, 2012;Bai et al, 2012;; and very close to the finding of Mukesh who reported that 32°C was optimal for cellulase production by B. cereus MRK1. Contrary to the result of this study however, maximum production of xylanase and cellulase by other bacterial species at both lower and higher incubation temperatures have been reported (Sepahy et al, 2011;Bibi et al, 2014), which is suggestive that optimal incubation temperature for cellulase and xylanase production is dependent on bacterial strain (Gautam et al, 2011).…”

“…Several Bacillus species includig B. circulans, B. amyloliquefaciens, B. halodurans, B. licheniformis, B. subtilis and B. mojavensis have been reported as producers of cellulase and xylanase (Ray et al, 2007;van Dyk et al, 2010;Sepahy et al, 2011;Acharya and Chaudhary, 2012). However, investigation of hemi (cellulolytic) bacteria from marine environment is on the increase due to their remarkable versatility and adaptation to heterogeneous environmental conditions (Lordan et al, 2011).…”

“…In that context hemi (cellulolytic) bacterial strains are continuously being sourced from diverse environments with a view to finding better alternative producers or other cellulases and xylanases capable of enhancing existing commercial enzyme cocktail preparations (Banerjee et al, 2010). Therefore investigation on novel bacterial strains adaptable to industrial process dynamics and capable of producing cellulases and xylanases with favourable industrial characteristics is ongoing (Sepahy et al, 2011;de Souza Vandenberghe et al, 2016).…”

Classical Optimization of Cellulase and Xylanase Production by a Marine Streptomyces Species

“…Ab 106. On the contrary, Sepahy et al [51] reported 200 rpm as optimal for xylanase production by Bacillus mojavensis AG137 cultured on agricultural waste. Whereas Saratale et al [31] reported static condition as optimal for endocellulase production by Streptomyces sp.…”

<b>Reuse of wastewater from pulp industry for the optimization of fungal xylanase production

“…However, increasing the production period failed to increase the levels of enzymatic activity. On the contrary, they would rather be reduced, suggesting the hypothesis that decrease was caused by depletion of nutrients or proteolysis due to secretion of nonspecific proteases (Sepahy, Ghazi, & Sepahy, 2011;Nasr, Soudi, Salmanian, & Ghadam, 2013).…”