中文摘要：

为降低微生物发酵产油成本,利用甘薯粗淀粉酶解液为碳源,从10株产油霉菌中筛选到一株能充分利用淀粉糖的菌株（S-1）,经5.8S r DNA-ITS序列分析,鉴定其为赤霉菌（Gibberella intermedia）.菌株S-1的初始生物量、油脂含量和油脂产量分别是15.82 g/L、31.51%和4.98 g/L,通过单因素和正交试验优化后分别提高到21.67 g/L、39.87%和8.64g/L,与优化前相比,油脂产量提高了73.5%.利用GC-MS对发酵提取后的油脂进行脂肪酸成分分析,主要成分为棕榈酸、亚油酸、油酸,与植物油相似,适用于生物柴油的生产,且不饱和脂肪酸含量达89.82%.本研究表明菌株S-1能够充分利用淀粉酶解液发酵产油,是生物柴油生产的潜在菌株.

英文摘要：

Microbial oil is a potential raw material for biodiesel. In order to reduce the cost of microbial lipid production, it is necessary to screen high oil producing strain that can make full use of sweet potato starch sugar and optimize the fermentation conditions. In the present study, the strain named Gibberella intermedia（S-1） identified by 5.8S r DNA-ITS sequence was screened by using sweet potato starch sugar as carbon source. To optimize the medium composition and fermentation conditions for lipid production by the strain S-1, experiments with single factor and orthogonal test were conducted. The strain S-1 had an initial biomass of 15.82 g/L, lipid content of 31.51% and lipid yield of 4.98 g/L, which increased to 21.67 g/L, 39.87% and 8.64 g/L, respectively, after optimization by single factor and orthogonal test. The lipid composition of the strain S-1 was determined by GC-MS. The results showed that the oil similar to vegetable oil, with 89.82% of it unsaturated fatty acid; the main contents were palmitic acid, oleic acid and linoleic acid, suitable to produce biodiesel. This research therefore suggested that the strain S-1 is able to take full advantage of the relatively cheap raw materials for microbial oil production and is a potential strain for biodiesel production.