Entomopathogenic fungi are widely available as biological control agents for controlling insect pests in agriculture and forestry. The fungal culture broth contains various pathogenesis-related components such as blastospores, mycelium and insecticidal enzymes such as chitinase, Pr1- and Pr2-proteases, which have been reported to play an important role in penetrating insect cuticles. In this study, we tried to evaluate the utility of culture broth from Beauveria bassiana SFB-205 to control lepidopteran pests. High level of insecticidal activity correspond to over 90% of mortality were observed when the culture broth of B. bassiana SFB-205 was inoculated to the Spodoptera litura larvae together with the B. thuringiensis K1. The freeze-dried culture broth showed synergistic effects in insecticidal activity against larvae of S. exigua and S. litura when treated with corresponding baculoviruses, SeNPV and SlNPV. Active ingredient of the B. bassiana SFB-205 culture broth was identified to chitinase, which have truncated form by insertional mutation compared to previously reported chitinases.

• Jae Young Choi(Research Institute for Agriculture and Life Sciences, Seoul National University)
• Yong Wang(Department of Agricultural Biotechnology, Seoul National University)
• Jong Yul Roh(Department of Agricultural Biotechnology, Seoul National University)
• Xueying Tao(Department of Agricultural Biotechnology, Seoul National University)
• Qin Liu(Department of Agricultural Biotechnology, Seoul National University)
• Jong Bin Park(Department of Agricultural Biotechnology, Seoul National University)
• Soo Dong Woo(College of Agriculture, Life and Environment Sciences, Chungbuk National University)
• Yeon Ho Je(Department of Agricultural Biotechnology, Seoul National University)