A New Temperature Control Shifting Strategy for Enhanced Triterpene Production by Ganoderma lucidum G0119 Based on Submerged Liquid Fermentation.

Temperature control is a very important factor on triterpene productivity in submerged liquid fermentation. Temperature effects from 23 to 32 °C on triterpene production by Ganoderma lucidum G0119 were investigated in 6-L stirred fermentor. Logistic and Luedeking-Piret equations were used to estimate the mycelial growth and triterpene production kinetics by regression analysis. On that basis, a temperature-shifting fermentation control strategy was established. From 0 to 61 h, culturing was performed at 32 °C to get high specific mycelial growth rate. Between 62 and 127 h, the temperature was decreased stepwise from 31 to 30 °C to maintain high triterpene productivity. After 128 h, temperature was maintained at 29 °C to minimize triterpene production inhibition and sustain high productivity. Elevated triterpene level (0.269 g L-1), yield (0.0101 g g-1), and productivity (0.00207 g (L h)-1) were achieved representing 27.32, 13.94, and 37.11 % higher than submerged liquid fermentation at constant temperature of 29 °C, respectively, feasible for the industrial scale.