利用微生物油脂制备生物柴油

Biodiesel Production with Microbial Lipid

考察了产油菌株粘红酵母(Rhodotorula gutini As2.107)的产油特性.结果表明,以葡萄糖为碳源,(NH_4)_2SO_4为氮源,培养基中加入微量 Mg^(2+),Ca^(2+)和 Fe^(2+),接种量为5%,温度为30℃,摇床转速为180 r/min 时,菌体的生物量可达到11 g/L,油脂产量可达4.3 g/L,其油脂的酸值为26.21 mgKOH/g 油,皂化值为231.86 mgKOH/g 油,平均分子量为818.78.油脂主要成份为软脂酸、硬脂酸、油酸和亚油酸.质量分数分别为17.80%,10.27%,53.02%和5.29%.以粘红酵母发酵所产微生物油脂为原料制备生物柴油,当醇油物质的量之比为20∶1,催化剂用量1.5%,反应温度60℃时,脂肪酸甲酯得率可达92%。

The characteristic of Rhodotorula gutinf As2. 107 for producing lipid was studied. The biomass was 11 g/L and the lipid concentration reached 4. 5 g/L with the optimal fermentation medium containing glucose 5%, （NH4）2SO40.25%, MgSO40.2%, CaCl20.01%, FeCl3 0. 007 %. The optimal fermentation temperature, rotation speed and inoculation size were 30 ℃, 180 rpm and 5% respectively. The acid value, saponification value and the average molecular weight were analyzed as 26.31 mgKOH/g oil, 231.86 mgKOH/g oil and 818.78. The components of the microbial lipid were palmitic acid 17.8%, steric acid 10.27%, oleic acid 53.02%, linoleic acid 5.29%, which was similar with that of vegetable oil. Based on the above results, biodiesel production with the microbial lipid of Rhodotorula gutini As2. 107 was investigated. The results indicated that the maximum methyl esters （ME） yield reached 93% by using alkali as the catalyst, with the molar ratio of methanol to oil 20 ： 1, 1.5% KOH and reaction temperature 60 ℃, after the high acid value of the microbial lipid was first lowed.