Polygalacturonase Production by Sarocladium strictum T4 Isolate using Apricot Pulp as Substrate in Non-Sterile Culture Conditions

In this study, 34 molds showing pectin degradation activity were isolated from the soil of orchards, by several tests. By using these isolates, pectinase group enzymes; studies on pectin lyase and polygalacturonase production were performed in the batch system and under non-sterile culture conditions. 5 isolates denoting polygalacturonase activity were coded as: T1, T2, T3, T4, T5 and the best polygalacturonase activity among these isolates was determined as 354.4 U/L in T4 isolate. Thus, optimization analyses continued by the use of this isolate. Initial apricot pulp concentration, temperature, pH and incubation period were tested as optimization parameters. The effects on enzyme activities were investigated by changing the initial apricot pulp concentration in the range of 5-100 (g/L), and in this regard, polygalacturonase activity was determined as 397.4 U/L at 50 g/L. In addition, the pH parameter was analyzed in each unit between pH = 3 – 8, and the temperature was tested by increasing 5 units in the range of 5-25°C. Consequently, the maximum polygalacturonase activity was determined as 405.7 U/L at pH 5 and 406.3 U/L at 15°C. Besides, the effect of the incubation period was studied within 1-5 days and the maximum polygalacturonase activity was determined as 429.0 U/L on the 4th day (after 96 hours). As a result, the above-mentioned T4 isolate, with which the optimization studies were conducted, was identified as Sarocladium strictum (Top ekinküfü) T4 by molecular methods.