Rhodotorula glutinis发酵糖蜜产油脂影响因素研究

 微生物油脂生产是解决生物柴油原料问题的重要途径之一。本文以制糖厂废糖蜜为原料，通过间歇发酵试验，考查了装液量、pH、接种量、温度，以及氮素和碳素等因素对黏红酵母（Rhodotorula glutinis）增殖与油脂合成的影响。结果表明，在稀释糖蜜COD浓度11100mg/L、初始pH值6.5、30℃和160r/min条件下发酵132h，黏红酵母的总细胞干重和油脂产量分别达到2.42和0.8g/L，去除单位COD的细胞产量和油脂产量分别为0.35和0.12kg/kg；在黏红酵母发酵系统中，氮源的补充对细胞增殖具有显著刺激作用，但对油脂合成与积累无显著影响；在发酵过程中一次性补加碳源葡萄糖10g/L，可使黏红酵母的细胞和油脂产量分别提高到3.74和1.3g/L。

Influencing Factors in Molass Fermentation by Rhodotorula glutinis for Microbial Oil Production

Microbial oil production is a feasible source of raw materials for biodiesel industry. Because of its excellent capability in grease synthesis and accumulation, Rhodotorula glutinis is a good candidate to produce microbial oil by molasses fermentation. The influencing factors, such as culture volume, pH value, inoculum concentration, temperature, nitrogen and carbon nutrition, were investigated by batch cultures. The results indicate that a dry-cell yield of 2.42g/L and a grease yield of 0.8g/L are obtained after fermenting for 132h with an initial COD concentration of 11100mg/L, pH value of 6.5, temperature of 30℃ and swing at 160r/min. The corresponding specific dry-cell and grease yield by COD removal are 0.35 and 0.12kg/kg, respectively. The dry-cell yield and grease yield could be increased to 3.74 and 1.31g/L, respectively, by adding 10g/L glucose instantly at a certain fermentation moment. The addition of nitrogenous nutriments to the fermentation system could promote the multiplication of R. glutinis remarkably, but has no observable influence on the grease yield.