渗透压调控对裂殖壶菌发酵产DHA的影响

摘要

考察了不同渗透胁迫(0、10、20、30和40 g/L NaCl)对裂殖壶菌HX-308发酵产DHA及脂肪酸构成的影响.结果表明:20 g/L NaCl最有利于裂殖壶菌生长和DHA积累,生物量、总脂肪酸含量、DHA产量及DHA占生物量的比值分别为73 g/L、10.7 g/L、5.0 g/L和68 mg/g,并且DHA在总脂肪酸中所占百分比最高,为45.2％.此外,在低渗透压(10 g/L NaCl)条件下,添加40 mmol/L甘氨酸甜菜碱,DHA产量与未添加相比提高了28.21％；在高渗透压(40 g/L NaCl)条件下添加40 mmol/L海藻糖,DHA产量提高了46.84％；表明添加适量的外源相容性溶质能有效地促进裂殖壶菌积累DHA.%The effects of different osmotic pressures(0 ,10 ,20,30 and 40 g/L NaCl)on DHA accumulation and fatty acids composition of Schizochytrium sp. HX-308 were studied. 20 g/L salinity was proved to be beneficial for cell growth and DHA production. Cell dry weight (DCW) , total content of fatty acids,DHA yield, and DHA concentration on DCW were the highest, around 73 g/L, 10. 7 g/L, 5. 0 g/L, and 68 mg/g, respectively. The DHA percentage of total fatty acids also reached the maximum of 45. 2% . In addition, under the conditions of 40 mmol/L glycine betaine addition under low salinity ( 10 g/L NaCl) and 40 mmol/L trehalose addition under high salinity (40 g/L NaCl) DHA yield could increase by 28. 21% and 46. 84% , respectively, thus demonstrating the positive effect of compatible solute addition to be effective for DHA production by Schizochytrium sp.