College of Biotechnology and Pharmaceutical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, No. 5 Xinmofan Road, Nanjing 210009, People's Republic of China.
Appl Biochem Biotechnol. 2011 Aug;164(7):979-90. doi: 10.1007/s12010-011-9189-z. Epub 2011 Feb 19.
The fermentation characteristics of Mortierella alpina were investigated in response to various nitrogen sources. Influences on nitrogen source and glucose uptake rate, mycelial morphology of M. alpina, and pH of medium in relation to different nitrogen sources were discussed. Effects of different nitrogen sources on cell growth, fatty acid composition, arachidonic acid (ARA), and total lipid concentration were also evaluated. It revealed that the maximum nitrogen source uptake ratio was obtained when corn steep liquor was used as nitrogen source. When yeast extract was used as the sole nitrogen source, glucose was completely exhausted at the end of fermentation. The maximum dry cell weight obtained from medium with yeast extract as nitrogen source had the highest total lipid concentration. Sodium nitrate was the favorable nitrogen source for ARA accumulation, and the highest ARA percentage in total fatty acids was obtained, 35.9%. Urea was identified as the favorable nitrogen source for ARA production, the highest ARA concentration obtained from urea was 5.8 g/l. Compared with inorganic nitrogen sources, organic nitrogen compounds are favorable for both cell growth and total lipids accumulation.
考察了不同氮源对蜡状枝霉（Mortierella alpina）发酵特性的影响。讨论了氮源和葡萄糖摄取率、蜡状枝霉菌丝形态以及不同氮源与介质 pH 值的关系。还评估了不同氮源对细胞生长、脂肪酸组成、花生四烯酸（ARA）和总脂质浓度的影响。结果表明，当使用玉米浆作为氮源时，最大的氮源摄取比例。当酵母提取物作为唯一氮源时，发酵结束时葡萄糖完全耗尽。从以酵母提取物为氮源的培养基中获得的最大干细胞重量具有最高的总脂质浓度。硝酸钠是积累 ARA 的有利氮源，获得的总脂肪酸中最高的ARA 百分比为 35.9%。尿素被鉴定为 ARA 生产的有利氮源，从尿素中获得的最高 ARA 浓度为 5.8g/L。与无机氮源相比，有机氮化合物有利于细胞生长和总脂质积累。
