Optimization of alkali-thermostable and cellulase-free eylanase production from Bacillus Sp.

Abstract

Context: To analyze the nutritional and physicochemical parameters for the production of alkali-thermostable and cellulase free xylanase from bacteria. Objectives:The aim of this study was to isolation and identification and of alkali-thermostable and cellulase free xylanase producing bacteria from soil as well as optimization of process parameters for xylanase production. Materials and Methods:The bacterium Bacillus sp. was isolated from soil by serial dilution technique on xylan agar medium and identified by morphological and biochemical studies. The production of xylanase was carried out on xylan broth medium and xylanase activity was assayed by dinitrosalicylic acid (DNS) method. The effect of cultural parameters on the production of xylanase was determined by measuring the activity of xylanase. The effect of temperature and pH on the activity of partially purified xylanase as well as substrate specificity of xylanase were examined. Results:The maximum xylanase production (4000 U/L) by a Bacillus sp. was attained when the medium containing 0.5% wheat bran xylan and peptone at pH 8.0 and 50-55°C within 48-60 h. The partially purified xylanase was optimally active at pH 9.0 and 55°C. The xylanase showed high substrate activity towards wheat bran xylan but no activity towards cellulose, carboxymethyl cellulose and starch. Thus the enzyme was alkali-thermostable and cellulase free xylanase. Conclusion:The results obtained in this study suggest that the Bacillus sp. used is highly potential and useful for the production of cellulase free xylanase.

Optimization of procedural factors for advanced xylanase synthesis by Lysinibacillus fusiformis using Kolanut husk as substrate

“…Temperature is another key dynamic that influences the success of optimization system. The best medium temperature was 35 o C which is close to the optimal temperature for utmost xylanase titre in submerged fermentation (SmF) (Table 7) from other Bacillus species reported as 37 °C (Qureshi et al 2002;Battan et al 2007;Geetha and Gunasekaran 2010;Nagar et al 2012) but contradicts the report of 50 °C temperature (Sa-Pereira et al 2002;Azeri et al 2010;Sepahy et al 2011), 50 -55 °C (Anuradha et al 2007;Sharma et al 2011) and 55 °C (Annamalai et al 2009). This indicates that productions of xylanase are favored at ambient temperature as compared to extremophilic temperature.…”