恒化培养稀释率和碳氮比对圆红冬孢酵母油脂积累的影响

采用恒化培养的方法,考察了稀释率(D)和碳氮比(mol/mol)对圆红冬孢酵母Rhodosporidiumtoruloides AS 2.138 9积累油脂的影响。结果表明:稀释率增大,油脂含量和油脂得率降低。在D=0.02 h 1时油脂得率最大,为0.18 g油/g糖;D=0.14 h 1时油脂生成速率最大,为0.09 g/(L.h)。碳氮比增大,油脂含量略有增加。在C/N=92时油脂得率最大,为0.12 g油/g糖;C/N=32时油脂生成速率最大,为0.13 g/(L.h)。碳氮比对油脂的脂肪酸组成影响不明显,油脂的棕榈酸、硬脂酸和油酸总含量超过85%。

Effects of dilution rate and carbon-to-nitrogen ratio on lipid accumulation by Rhodosporidium toruloides under chemostat conditions

The objective of this work is to investigate how dilution rate and carbon-to-nitrogen(C/N) ratio affects lipid accumulation by Rhodosporidium toruloides AS 2.138 9 in continuous culture.Under steady-state conditions,the increase in dilution rate led to the decrease in lipid content and lipid yield.The highest lipid yield and lipid content at D=0.02 h?1 were 0.18 g lipid/g sugar and 57.1%,respectively,while the highest lipid productivity and biomass productivity were obtained at D=0.14 h?1.The increase in C/N ratio led to the increase in lipid content.The highest lipid content of 38% was obtained at C/N=237.The highest lipid yield of 0.12 g lipid/g sugar was obtained at C/N=92.However,the highest lipid productivity of 0.12 g/(L?h) was obtained at C/N=32.No significant changes were observed in terms of fatty acid composition of the lipid produced under different C/N ratios,and these three fatty acids,palmitic acid,stearic acid and oleic acid,took over 85% in all samples.