Abstract

Paecilomyces lilacinus is known as an effective parasite on nematodes which cause diseases to plants. P. lilacinus shows potential as a biocontrol agent against plant parasitic nematodes. The objective of this study is to optimize culture methods including nutritional requirements and environmental factors. The optimized culture conditions for biomass yields of P. lilacinus M-14 were spore suspension on basal medium (sucrose 19.00 g, soy peptone 4.06 g, K₂HPO₄ 1.00 g, KCl 0.50 g, MgSO₄ 0.50 g, FeSO₄ 0.01 g and 17.00 g Bactor) for the first stage culture of 4 days under room condition for fungal growth, and then moved to another medium (maltose 5.00 g, soy peptone 2.50 g, ZnSO₄·7H₂O 0.25 gL^-1, Na₂MoO₄·2H₂O 0.005 gL^-1, H₃BO₄ 0.005 gL^-1, CuSO₄·5H₂O 0.01 gL^-1 and 17.00 g Bactor) for another 4 days culture. The environmental factors combination was water potential -1.2 MPa/pH 3/light 12 h/temperature 29°C for biomass yields, and for sporulation of P. lilacinus M-14 under the environmental conditions, it was water potential -1.2 MPa/pH 3/24 h light/29°C. It will provide valuable insight into culturing of the biocontrol fungus.

Key words: Biomass, environment, Paecilomyces lilacinu, biocontrol fungus.