Journal of Agricultural Technology 2013, Vol. 9(5): 1157-1165 1157 Production of an antibacterial compound against the plant pathogen Erwinia carotovora subs. carotovora by the biocontrol strain Gliocladium sp. T.N.C73 Hendra Saputra 1 , Fifi Puspita 2 and Titania Tjandrawati Nugroho 1 1 Department of Chemistry, Faculty of Mathematics and Natural Science, University of Riau, Pekanbaru, Riau, Indonesia, 2 Department of Agrotechnology, Faculty of Agriculture, University of Riau, Pekanbaru, Riau, Indonesia Hendra Saputra, Fifi Puspita and Titania Tjandrawati Nugroho (2013) Production of an antibacterial compound against the plant pathogen Erwinia carotovora subs. carotovora by the biocontrol strain Gliocladium sp. T.N.C73. Journal of Agricultural Technology 9(5):1157-1165. Gliocladium sp. T.N.C73 was originally isolated as a biocontrol agent from suppressive soil against the phytopathogen Phytophtora capsici. Apart from producing chitinase, this biocontrol fungal strain also produces secondary metabolites having antibacterial properties against the Gram positive bacteria Bacillus subtilis and Staphylococcus aeureus. In order to further explore the ability of Gliocladium sp. T.N.C73 in managing plant diseases caused by bacteria, ethyl acetate extracts of the fermentation medium of this strain was analyzed for its ability to inhibit the Gram negative Erwinia carotovora subsp. carotovora that causes soft rot disease in food crops. Disc diffusion bioassays showed that the extracts could inhibit E. carotovora subsp. carotovora growth. Depending on the initial spore concentration of the fermentation medium inoculum, several compounds were detected by thin layer chromatography (TLC) of the ethyl acetate extracts that fluorescence under UV light, and one compound that gave a bright red spot when sprayed with a p-anisaldehyde solution. Keywords: Gliocladium, Erwinia carotovora, soft rot, biocontrol agent. Introduction Sustainable agriculture practices require the use of biological control agents (BCAs) to manage plant diseases, in place of synthetic chemicals. Several biocontrol mechanisms have been identified in BCAs, namely mycoparasitism involving cell wall degrading enzymes, nutrient competition, production of secondary metabolites acting as antibacterials or antifungals, and production of metabolites that can induce plant resistance (Punja and Utkhede, 2003; Harman, 2006; Shoresh et al., 2010). Modeling and experimental studies  Corresponding author: Titania T. Nugroho; email: titanianugroho@gmail.com; titania_nugroho@unri.ac.id Journal of Agricultural Technology 2013 Vol. 9(5): 1157-1165 Available online http://www.ijat-aatsea.com ISSN 1686-9141