| Summary: | 碩士 === 東海大學 === 化學工程學系 === 90 === The main objective of this research is to study the effects of cultural conditions on the formation of superoxide dismutase (SOD) in the submerged culture of Ganoderma lucidum. In addition, the response surface method (RSM) was employed to determine the interaction effects of factors, such as C-source, N-source and initial pH.
The strain of Ganoderma lucidum CCRC 37200 was chosen and the experiments were carried out in shake flasks to determine the optimal cultural conditions. The results indicated that the condition with the temperature of 30℃, was the initial pH of 5, the rotary speed of 100rpm, and the inoculums density of 8% was in favor of the SOD production. Under that condition, the mycelium concentration and intracellular SOD activity could reach 586.89mg/100ml and 255.46/g d.w., respectively, in a 7-day culture. A number of carbon sources were tested in order to determine their effects on the growth of mycelium and SOD production. The activity of SOD obtained with sucrose was higher than that with glucose. The results showed that the combination of yeast extract and peptone was the best choice for nitrogen source. The addition of H2O2 could induce the formation of SOD, although it might reduce the growth rate of mycelia. By examination different carbon and nitrogen sources, sucrose, peptone, and yeast extract were selected for the following test of RSM to study the interaction effects of C-source concentration, N-source concentration, and initial pH. With the optimal composition determined by RSM, which was consist of 2.33% of sucrose, 0.106% of peptone, 2.59% of yeast extract, and the initial pH of 6.05, the concentration of SOD could reach 1604mg/100ml on the 7th day and which was more 5-fold.
The results demonstrated that the cultural conditions had a great influence on the formation of SOD. The optimal conditions determined by the RSM effectively increase the productivity of SOD in shake flask cultures of Ganoderma lucidum.
|
|---|
