The Effect of Environmental Conditions on Penicillin Fermentations with Penicillium chrysogenum X-1612

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Abstract
Incubation temp. from 20 to 29[degree]C did not affect penicillin yield in 200-liter tank batches. Incubation at 32[degree] lowered the yield. Penicillin yields of 400 U. per ml. were obtained with internal tank pressures of 2 and 20 lbs. per sq. in. 275 U. (av.) were produced at 40 lbs. pressure. The slow pH rise and the low NH3-N levels at the later stages of the high pressure fermentation may have limited penicillin formation. Increased CO2 tension in the medium and in the exhaust air (0.7 to 2.5% CO2) did not affect penicillin production. Substitution of glucose for lactose as a carbohydrate source resulted in rapid glucose utilization at a pH value too low for rapid penicillin formation, followed by autolysis after glucose exhaustion. Lard, lard oil, soybean oil, corn oil, Nopco defoatner, Vegifat Y, 3% octadecanol in lard oil, and 3% octadecanol in soybean oil were tested as antifoam agents in shake flask fermentations. 3% octadecanol in lard oil or 3% octadecanol in soybean oil were the most useful. Nopco defoamer and Vegifat Y were the most effective anti-foam agents but were the most toxic.