dl-2 Aminobutyric acid and calliterpinone are the potential stimulators of Trichoderma cellulase activities

Trichoderma citrinoviride EB-104 has recently been developed as a hyper β-glucosidase producing mutant strain. In the present study, efforts were made to further enhance its enzyme titers using low molecular weight stimulators viz., calliterpinone (a natural plant diterpenoid), dl-2-aminobutyric acid (isomer of an amino acid, aminobutyric acid) and jasmonic acid (a natural plant growth regulator). Among test stimulators, calliterpinone and dl-2-aminobutyric acid significantly enhanced activities of all three enzymes of cellulase complex i.e., FPase, endoglucanase and β-glucosidase. A 5.0 and 2.7 fold increase in FPase and endoglucanase activities, respectively, could be achieved by incorporating 12.5 mmol dl-2-aminobutyric acid into fermentation media. On the other hand, more than fivefold enhanced β-glucosidase activity was evident with 10 μmol of calliterpinone, raising its activity from 8.28 to 43.38 IU cm−3. This β-glucosidase activity of T. citrinoviride EB-104 is far higher than that of reported earlier. These test stimulators, which improved enzyme activities of cellulase complex in T. citrinoviride EB-104, may also be explored for enhancing the activities of other fungal enzymes.