D. E. Brown

Effect of temperature and pH on lipid accumulation by Trichoderma reesei

SummaryThe fungal micro-organism Trichoderma reesei was grown in batch culture with excess glucose at pH values between 2.7 and 4.5 and temperatures between 25°C and 35°C. A maximum lipid concentration of 16.9% of the cell dry weight was achieved at pH 3.2 and a temperature of 27°C. Lipid concentration was shown to be correlated with a calculated maximum specific growth rate (µmc) and the maximum lipid value occurred at µmc = 0.10 h−1. Fatty acid analysis was carried out and found to change with changing pH and temperature. Palmitic (16:0) acid and unusually high proportions of stearic acid (18:0) were commonly present. A conversion of fatty acids to palmitoleic acid (16:1) occurred following an unidentified nutrient limitation other than nitrogen depletion after 70 h of culture.

Fat production byTrichodermareesei

SummarySnake flask experiments were carried out as a preliminary study of fat formation byTrichodermareesei (formallyviride) QM 9123 using a glucose based medium. The maximum quantity of fat production was 16% of the dry weight. The pH of the medium, as much as its composition, appeared to influence the quantity of fat that was produced. The fatty acids formed by the hydrolysis of the fats were found to be mainly unsaturated, with the 18∶2 (linoleic) acid predominating.