Abstract

This study focus on the production of antibacterial compound from Trichoderma spp. Screening of antibacterial activities in some Trichoderma spp. was investigated using CYS80 medium. Trichoderma reesei and Trichoderma viride were highly effective toward human-pathogenic bacteria tested. T. viride and T. reesei were separately applied on Sephacryl S–200 column. Column fractions No. 56 to 64 for T. viride and fractions No. 57 to 66 for T. reesei had inhibitory effect against the most pathogenic bacteria examined. T. reesei and T. viride Sephacryl S-200 fractions with antibacterial activity were analyzed byGas chromatography–mass spectrometry (GC- MS). The product with highest peak (95%), using different libraries, was kojic acid. The yield of kojic acid crystals from T. reesei and T. viride Sephacryl S-200 fractions were 3 and 5 g/L, respectively. Physical analysis of kojic acid with respect to UV, IR, ¹HNMR analysis and melting point was examined. The minimum inhibitory concentration (MIC) of kojic acid and augmentin, as control, against human-pathogenic bacteria were evaluated. Kojic acid and augmentin showed a similar time-killing kinetics with human-pathogenic bacteria. The level of kojic acid increased with decreased level of reducing sugar during the growth of T. reesei and T. viride suggesting that the enzyme system for the synthesis of kojic acid found in the cell of these fungi.

Key words: Trichoderma spp., human-pathogenic bacteria, kojic acid, minimum inhibitory concentration.