Partial characterization of ß-glucosidase, ß-xylosidase, and a-larabinofuranosidase from Jiangella alba DSM 45237 and their potential in lignocellulose-based biorefining

Jiangella alba DSM 45237 exhibited excellent extracellular ss-glucosidase (1.03 +/- 0.09 U/mL), ss xylosidase (16.29 +/- 0.23 U/mL), and alpha-l-arabinofuranosidase (7.00 +/- 0.09 U/mL) production in the growth media containing 15 g/L wheat straw pretreated with NaOH. The optimum temperature was 40 degrees C for ss-glucosidase and ss-xylosidase, whereas it was 50 degrees C for a-larabinofuranosidase. Among them, alpha-l-arabinofuranosidase was relatively stable at 60 and 70 degrees C. Enzymes showed maximum activity at pH 8.0. Enzymes, particularly ss-glucosidase and al-arabinofuranosidase, were able to tolerate NaCl up to a final concentration of 12% (v/w). Among solvents, only ethanol and methanol increased the ss-glucosidase activity. The majority of solvents did not significantly affect ss-xylosidase activity but increased alpha-l-arabinofuranosidase activity. Except for phenol, other lignocellulose-derived compounds did not cause a significant activity loss in enzymes. Some of them, such as vanillic acid and acetic acid, have even increased the activity of enzymes. Hydrolysis of pretreated wheat straw using the crude enzyme from J. alba DSM 45237 released 160.9 mg/gds reducing sugars. Analysis of hydrolysis products with thin layer chromatography (TLC) showed that major products were 5C sugars. This is the first report related to the characterization of ss-glucosidase, ss-xylosidase, and alpha-l-arabinofuranosidase from J.alba DSM 45237 to date.