【摘要】 以玉米粉糖液为碳源,用深黄被孢霉突变株发酵生产多不饱和脂肪酸。研究氮源种类、碳氮源质量比、碳源质量浓度、硫酸镁质量浓度、接种量体积分数、p H、温度和发酵时间对菌株发酵效果的影响。以生物量和油脂产量为评价指标,通过单因素及正交试验优化确定发酵条件。结果表明:选定氮源为酵母粉、碳氮源质量比30∶1,最佳发酵条件为碳源质量浓度80.0 g/L、氮源质量浓度2.7 g/L、硫酸镁质量浓度0.7 g/L、柠檬酸钠质量浓度2.0 g/L、磷酸二氢钾质量浓度2.0 g/L、接种量体积分数10%、pH 6.0、温度26℃、发酵时间6 d。在此条件下,深黄被孢霉菌体生物量和油脂产量达26.12、14.63 g/L。经气相色谱分析深黄被孢霉油脂中脂肪酸组成为肉豆蔻酸、棕榈酸、棕榈一烯酸、硬脂酸、油酸、亚油酸、花生酸、γ-亚麻酸、α-亚麻酸,其中不饱和脂肪酸含量81.45%、多不饱和脂肪酸含量16.28%。更多还原

【Abstract】 The polyunsaturated fatty acids were produced by the mutant strain of Mortierella isabellina,using corn flour sugar solution as carbon source. The effects of type of nitrogen source, mass ratio of carbon sources to nitrogen sources, mass concentration of carbon source, mass concentration of magnesium sulfate, inoculation volume fraction, pH, temperature and fermentation time on the fermentation effect of the strain were studied. Using biomass and oil yield as evaluation indexes, the fermentation conditions were optimized by single factor and orthogonal experiments. The results showed that yeast powder was selected as the nitrogen source and the mass ratio of carbon sources to nitrogen sources was 30 ∶ 1. The optimal fermentation conditions were as follows: the mass concentration of carbon source 80. 0 g/L, nitrogen source 2. 7 g/L, magnesium sulfate 0. 7 g/L, sodium citrate 2. 0 g/L, potassium dihydrogen phosphate2. 0 g/L, inoculation volume fraction 10 %, pH 6. 0, temperature 26 ℃ and fermentation time 6 d. Under these conditions, the biomass and oil yield of Mortierella isabellina reached 26. 12 and 14. 63 g/L fatty acid composition in the oil of Mortierella isabellina was determined by gas chromatography to be myristic acid, palmitic acid, palmitic monoenoic acid, stearic acid, oleic acid, linoleic acid, arachidonic acid, γ-linolenic acid and α-linolenic acid. The content of unsaturated fatty acid and polyunsaturated fatty acid were 81. 45 % and 16. 28 % respectively.更多还原