ABSTRACT

Background: The chitinase enzyme has received increased attention due to its wide range of biotechnological applications,especially in agriculture for the biocontrol of fungi. In this study, chitinolytic bacteria from shrimp farms (East Java, Indonesia) were isolated and evaluated for their antifungal activity. Material and methods: Screening of chitinolytic bacteria in the media containing colloidal chitin was determined by colorimetric activity using a UV-Vis spectrophotometer. Isolates with the highest activity are determined species based on physiology, morphology, and the 16S-rRNA gene. Chitinase enzymes from selected isolates are tested as antifungals of chili plants by measuring their taste ability through the formed clear zones. Result: There were 24, 40, 54, and 78 isolates of bacteria from shrimp farms in Tuban (TB), Situbondo (ST), Lamongan (LA), and Sidoarjo (SD) in Indonesia respectively. Based on enzyme production, four isolates namely LA21 (0.73 U / mL), SD54 (0.663 U / mL), TB11 (1.160 U / mL), and ST7 (0.405 U / mL) were selected for further analyzed and evaluated. Phylogenetic analysis revealed that the LA21 isolates have homologous with Bacillus cereus, morphological and biochemical tests showed that isolate TB11 is thought to be a group of Vibrio alginolyticus while isolating ST 13 belongs to Bacillus licheniformis. The LA21 isolate displayed antifungal activity against Fusarium oxysporum f.sp. capsici and Colletotrichum capsici during the trial period. Conclusion: This study demonstrated that chitinolytic bacterial isolates from various shrimp farms have great potential for chitinase production and antifungal applications.