生物柴油副产品粗甘油浓度对裂殖壶菌生长与积累油脂的影响

摘要

在研究了生物柴油副产品粗甘油培养裂殖壶菌(Schizochytrium sp.)WZU6961产油脂的优化培养条件的基础上,对粗甘油浓度对裂殖壶菌生长和积累油脂的影响进行研究.结果表明,在温度、溶氧及培养基其他成分相同的培养条件下,随着粗甘油浓度的增加,菌体油脂含量和脂肪酸组成没有显著的变化;但甘油的生物量和油脂得率系数以及生物量生产率和油脂生产率逐渐下降,说明粗甘油浓度过高对细胞的生长有抑制效应;当粗甘油质量浓度分别为30 g/L和60 g/L时,生物量生产率分别为0.94 g/(L·h)和0.87 g/(L·h),油脂生产率分别为0.69 g/(L· h)和0.64 g/(L· h),两者的生物量生产率和油脂生产率比较接近,因而可以得出适宜的粗甘油质量浓度为30 g/L.在粗甘油质量浓度30 g/L下,发酵时间26 h,生物量、菌体油脂含量和DHA占油脂的比例分别为(24.38±1.42) g/L、(74.08±2.20)％和23.72％.%Based on the optimization of fermentation of oil-producing Schizochytrium sp.WZU 6961 with biodiesel byproduct crude glycerol,the effect of the concentration of crude glycerol on the strain's growth and lipid accumulation was studied.Using the same culture condition including temperature,dissolve-d oxygen,and the same other medium ingredients,the results showed that there was no significant change of the oil content and fatty acid composition with the increase of crude glycerin concentration,while the biomass and oil yields of glycerol,and the productivities of biomass and oil were gradually declined,which meant that high crude glycerol concentration had inhibitory effect on the growth of cells.For crude glycerol concentration of 30 g/L and 60 g/L,biomass productivity was 0.94 g/(L · h) and 0.87 g/(L · h) respectively,and oil productivity was 0.69 g/(L · h) and 0.64 g/(L · h) respectively,which was close to each other in the productivities of biomass and oil.So the suitable crude glycerol concentration was 30g/L.When crude glycerol concentration was 30 g/L,fermentation time was 26h,biomass,oil content and the proportion of DHA in oil were 24.38 ± 1.42g/L,74.08％ ± 2.20％ and 23.72％,respectively.