Isolation of cellulase-free xylanase Bacillus sp. strains, enzyme production, characterization and investigation of biotechnological applications

In this study, the cellulase free xylanase enzymes from Bacillus sp. strains isolated from different environments were produced and characterized. For this purpose, different temperatures and pH values of bacteria and enzymes to produce reproductive capabilities on solid plate were investigated. Besides, different chemicals and NaCl effects on the enzyme activity was determined.Molecular weight of the enzyme from Bacillus sp. X6 was estimated as 62.4 and 22 kDa on SDS-PAGE. The optimum activity was obtained at 30ºC. The enzyme was retained it?s activity around %86 at the end of 60 minutes between 30-100 ºC. The optimum activity was obtained at pH 8.0. The enzyme also presented the alkali-stable properties with a residual activity around 57% at 30 ºC between pH 7.0-12.0 for 24 hours. The optimum activity of X6 xylanase has shown 60% in the 15% NaCl concentration. H2O2 (%75), MnCl2 (%65) and ß-mercaptoethanol (%149) stimulated the enzyme activity significantly however the other chemicals reduced. Maltose was obtained as a hydrolysis product by thin layer chromatography.According to these result, X6 enzyme shows psychrotolerant, extreme-thermophile, mesophile, alkaliphile, halotolerant, thermostable and alkali-stable characters. Due to these properties X6 cellulase free xylanase enzyme has capable of using at bio-bleaching applications, paper and pulp industry, clarification processes of fruit juice and bleaching prosseses at textile industry.