Fermentable sugars production from lignocellulosic materials hydrolysis by thermophilic enzymes from Bacillus subtilis J12

Hot spring water and soil samples collected from various locations in Thailand were screened as thermophilic lignocellulase producers. Isolate J12, which showed the highest carboxymethylcellulase (CMCase) activity was selected for further enzymatic characterization. The isolate J12 exhibited both CMCase and xylanase acitvities. Optimum temperature for the J12 CMCase and xylanase acitvities were found to be the same at 60°C. But optimum pH were slightly different at pH 6.0 and 5.5, respectively. Both enzymes were stable at high temperatures and retained more than 60 % of their activities after 20 min at 60°C. Therefore, CMCase and xylanase produced from the selected bacterium showed thermophilic properties as to stability as well as activity. Plant degradation potential of J12 enzymes was also investigated using corncob and Napier grass. The result revealed that hydrolytic efficacy of this enzyme on corncob 13.2 % was superior to Napier grass at 9.6 %. Morphology and 16S rDNA sequencing results indicated that the bacterial isolate J12 was Bacillus sp.