甘蔗糖蜜发酵生产多不饱和脂肪酸的菌种筛选

利用苏丹黑B染色和测定多不饱和脂肪酸碘值的方法,从土壤中筛选出一株适合用甘蔗糖蜜为原料生产多不饱和脂肪酸的霉菌LB1。研究表明,该菌株培养的最适糖蜜浓度为10°BX,通过单因素实验和正交实验设计,确定了优化培养条件:最适温度28℃、摇床转速为160r/min、pH值为6.0和培养天数为5d。在优化条件下,菌株的油脂含量为其生物量的57.08%,其中油脂中多不饱和脂肪酸的组成及含量为:油酸15.42%,亚油酸14.38%、γ-亚麻酸23.55%、α-亚麻酸3.06%、花生四烯酸9.87%、廿碳五烯酸8.14%、廿二碳六烯酸6.07%等。多不饱和脂肪酸的含量占总脂肪酸的80.49%。对LB1菌株进行形态特征、生理特征分析及5.8S rDNA基因两侧的内转录间隙进行序列分析推测该菌株为反屈毛霉。

Screening of microorganism producing polyunsaturated fatty acids with sugarcane molasses

A strain name LB1 producing polyunsaturated fatty acids with sugarcane molasses was screened form soil samples by the methods of Sudan Black B stain and the determination of PUFAs' iodine value. Based on the grass morphological and physiological characteristics and the sequence similarity of ribosomal DNA-ITS, the strain was identified as Mucor recurvus sp.. The results of L64 (4(3)) orthogonal experiments indicated when Mucor recurvus was cultivated at 28 degrees C for 5 days with 160 r/min, the yields of PUFAs with 10(0) BX sugarcane molasses (pH 6.0) were up to 80.49% content of total fatty acids. The total lipids content was 57.08% of fermentation biomass, which were composed of 15.42% Oleic acid, 14.38% Linolenic, 23.55% gamma-Linolenic, 3.06% alpha-Linolenic, 9.87% Arachidonic acid, 8.14% Eicosapentaenoic acid, 6.07% Docosahexaenoic acid, etc.