氮源调控Schizochytrium sp.DP-16发酵产DHA油脂

Regulation of nitrogen source on DHA oil fermentation by Schizochytrium sp.DP-16

利用一株海洋真菌Schizochytrium sp.DP-16发酵产DHA油脂,从有机氮源、无机氮源两方面研究不同氮源种类和浓度下DHA油脂积累情况。利用GC分析DHA占总脂肪酸的质量分数,结果表明,在牛肉膏、玉米浆、蛋白胨、酵母浸粉4种有机氮源中,添加酵母浸粉15 g/L,油脂产量达到20.7 g/L,相比对照组提高了16.9%。添加谷氨酸钠10 g/L,油脂产量为22.8 g/L,DHA占总脂肪酸质量分数的36.6%,相比对照组提高了11.2%和28.4%。硝酸钠、硫酸铵、氯化铵3种无机氮源中,添加氯化铵1.5 g/L,DHA产量占总脂肪酸的质量分数高达41.5%,相比对照组提高了17.5%。油脂发酵结果表明,添加酵母浸粉15 g/L和谷氨酸钠10 g/L氮源复配条件下发酵效果可观。

A marine fungus Schizochytrium sp.DP-16 was used to ferment DHA oil.The accumulation of DHA oil were studied under different nitrogen sources and concentrations from organic and inorganic nitrogen sources.DHA content in total fatty acid was analyzed by GC.The results showed that in beef extract,corn syrup,peptone and yeast extract,the oil yield could reach 20.7 g/L when 15 g/L yeast extract was added to the basic medium,which was 16.9%higher than that of the control group.When 10 g/L sodium glutamate was added,the oil yield and DHA content in total fatty acid reached 22.8 g/L and 36.6%,respectively,which were 11.2%and 28.4%higher than that of the control group,respectively.When 1.5 g/L ammonium chloride was added to the three inorganic nitrogen sources(sodium nitrate,ammonium sulfate and ammonium chloride),the content of DHA in total fatty acids reached 41.5%,which was 17.5%higher than that in the control group.The result of oil fermentation showed that 15 g/L yeast extract and 10 g/L sodium glutamate were effective.