Kemampuan Bakteri Kitinolitik Lokal dalam Menghambat Pertumbuhan Fusarium Sp Tanaman Kopi

Abstract

A study on the ability of chitinolytic bacteria to inhibit the growth of Fusarium sp. isolated from coffee plant, has been conducted from Juni until Desember 2010. The pathogenic fungi were isolated from leaves, fruits, and branches of coffee plant in Brastagi. Whereas fungi isolation, identification and antagonistic examination were conduced in Microbiology Laboratory, Biology Department, Faculty of Mathematic and Natural Sciences, Sumatera Utara University. The purpose of this study was to investigate the chitinolytic bacteria to inhibit the growth of Fusarium sp. pathogenic in the coffee plant. The results showed that four species of Fusarium were obtained from the coffee, which were Fusarium sp. 1, Fusarium sp. 2, Fusarium sp. 3, and Fusarium sp. 4. The chitinolytic bacteria tested were BK07, BK08, BK09, BK13, BK14, BK15, BK16, BK17, KR05, LK08 obtained from Microbiology Laboratory, Department of Biology, Sumatera Utara University. The Antagonistic assay has been conducted using chitin salt minimum media. The antagonistic assay was observed after ninth days of incubation, the results showed that BK15 effective bacteria in inhibiting the growth of the Fusarium with the diameter of clear zone of 2,18 cm, mean while BK09 showed relative low ability to inhibit the growth of the Fusarium sp. 4 with the diameter of clear zone of 0,25 cm. Based on microscopic observation, the chitinolytic bacteria caused abnormal hypae such as lytic, broken, coiled, rolled, and curly hyphae.