Identification of Newly Isolated Talaromyces pinophilus and Statistical Optimization of β-Glucosidase Production Under Solid-State Fermentation

Fungi able to degrade agriculture wastes were isolated from different soil samples, rice straw, and compost; these isolates were screened for their ability to produce beta-glucosidase. The most active fungal isolate was identified as Talaromyces pinophilus strain EMOO 13-3. The Plackett-Burman design is used for identifying the significant variables that influence beta-glucosidase production under solid-state fermentation. Fifteen variables were examined for their significances on the production of beta-glucosidase in 20 experimental runs. Among the variables screened, moisture content, Tween 80, and (NH4)(2)SO4 had significant effects on beta-glucosidase production with confidence levels above 90% (p<0.1). The optimal levels of these variables were further optimized using Box-Behnken statical design. As a result, the maximal beta-glucosidase activity is 3648.519Ug(-1), which is achieved at the following fermentation conditions: substrate amount 0.5 (g/250mL flask), NaNO3 0.5 (%), KH2PO4 0.3 (%), KCl 0.02 (%), MgSO4 center dot 7H(2)O 0.01 (%), CaCl2 0.01 (%), yeast extract 0.07 (%), FeSO4 center dot 7H(2)O 0.0002 (%), Tween 80 0.02 (%), (NH4)(2)SO4 0.3 (%), pH 6.5, temperature 25 degrees C, moisture content 1 (mL/g dry substrate), inoculum size 0.5 (mL/g dry substrate), and incubation period 5 days.