Proceeding ITB, Vol. 32, (3) : 85-91 (2000)
Dini Jamiah Rayati; I Nyoman P. Aryantha and Purwo Arbianto
Department of Biology, Faculty of Mathematics and Sciences ITB
Jalan Ganesha 10 Bandung Indonesia
Paecilomyces fumosoroseus has been reported to be potential as a biocontrol agent for insect pests. The mass spore production of the fungus still needs to be developed. This research was trying to find out the optimum condition for producing the mass spore production of the fungus. At submerged-fermentation stage (vegetative growth), the nutrition factors (i.e. carbon, nitrogen source and C/N ratio) were optimized, whereas at surface-fermentation stage (sporulation) nutrient concentration was optimized. The results show that three kinds of carbon source (i.e glucose, maltose, and sucrose) gave the same mycelial growth for P. fumosoroseus. The organic nitrogen sources (i.e glysine, glutamine, serine, alanine, asparagines and a mixture of the first four amino acids) gave a better significant growth for P. fumosoroseus (a=0,05) compared with the inorganic -nitrogen source (sodium nitrate and ammonium chloride). The optimum C/N ratio for the mycelial growth of the fungus was found at 14 value. Finally, the optimum nutrient condition for sporulation was found in the stationary growth phase medium by transferring the harvested mycelium into a flat container. At this optimum condition the fungus produced an average of 4.5 x 109 spre per gram mycelium after 190 hours. These results suggests that the mass spore production of P. fumosoroseus could be done by using two steps fermentation system by using organic substrate containing amino acids and sugars such as wheat or rice bran and mollases.
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Biological control, Entomopathogenic fungus, fumosoroseus, two-stage fermentation
