EVALUATION OF ANTIFUNGAL SUBSTANCES PRODUCED BY BACILLUS SUBTILIS AGAINST PHYTOPATHOGENIC FUNGI (GANODERMA BONINENSE)

• Main Author: SINGHALATH, Sinpakone
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/35902
• Institution: Institut Teknologi Bandung

Ganoderma boninense is a fungal pathogen in oil palm plantations which can cause basal stem rot (BSR) which is difficult to be eradicated. This deadly disease has caused major losses in the oil palm industry and no remedy is reported to date. The more promising control on G. boninense is the use of biological control agent (BCA). The objectives of this study were to determine the optimum culture incubation time for antifungal substances against G. boninense and hydrolytic enzyme (?-glucanase and chitinase) production by B. subtilis as well as optimum pH and temperature condition for enzymatic activity and to determine the optimum solvent (methanol, ethyl acetate or hexane) for extraction the metabolite. The results showed that ?-glucanase could be optimally produced (with a specific activity 4.222 U/mg-protein) after 28-hour of incubation. Optimum pH and temperature of ?-glucanase were at pH 7.5 and 45°C respectively, using 1% laminarin as substrate. B. subtilis showed optimum chitinase activity (0.0514 U/mL) after 8-hour of incubation. Optimum pH and temperature of chitinase were pH 6.0 and 40 °C respectively, using, using 1% colloidal chitin as substrate. It also showed that ?-glucanase crude enzyme significantly inhibited the mycelial growth of G. boninense better than crude enzyme of chitinase with inhibition rate of 47.75%. Furthermore, the better solvent used to extract metabolite from B. subtilis was ethyl acetate that gave value of inhibition by 38.91%. Antifungal product from B. subtilis can be used as potential biological control agent against G. boninense in the oil palm plantation.