掷孢酵母发酵红薯淀粉酶解液产油脂的发酵条件

Fermentation Conditions for Lipid Production by Sporobolomyces reseus with Sweet Potato Starch Hydrolysates

利用红薯粗淀粉酶解液为碳源进行发酵试验,采用单因素和均匀设计试验法对掷孢酵母(Sporobolomyces reseus)As.2.618产油脂发酵培养基进行优化,考察了二价金属离子及氧载体正十二烷对油脂积累的影响,以期降低微生物油脂的成本.通过DPS软件对均匀设计结果进行二次逐步回归分析,给出最优培养基组成(ρ/gL-1)为:还原糖103、酵母粉11.5、磷酸二氢钾0.3、硫酸镁0.15.在此基础上添加30mgL-1硫酸锌.在发酵条件为初始pH6.0,发酵温度27℃,转速200r/min,装液量30mL/500mL三角瓶,接种量5%,发酵24h后添加2gL-1CaCO3和2%(V/V)正十二烷,振荡培养至168h,菌体生物量高达35.05gL-1,油脂产量也达到11.98gL-1.

To optimize medium composition and fermentation conditions for lipid production by Sporobolomyces reseus, the experiments with single factor and uniform design were conducted. The effects of divalent metal ions and oxygen vector （n-dodecane）on lipid accumulation were studied. The optimum medium obtained from the above experiments consisted of reducing sugar 103 g L^-1, yeast extract 11.5 g L^-1, KH2PO4 0.3 g L^-1, MgSO4 0.15 g L^-1, and ZnSO4 30 mg L^-1. The fermentation conditions were： initial pH 6.0, fermentation temperature 27 ℃, rotation speed 200 r/min and the 500 mL flasks contained 30 mL medium with 5% inoculation volume, and after 24 h fermentation, 2 g L^-1 CaCO3 and 2% （V/V） n-dodecane were added. Then, the medium was shaken for 168 h, and the biomass was found as high as 35.05 g L^-1 and lipid was 11.98 g L^-1. Fig 3, Tab 2, Ref 13