利用乙醇发酵副产CO_2培养富含淀粉亚心型四爿藻作为其补充原料

Ethanol production with starch-based Tetraselmis subcordiformis grown with CO_2 produced during ethanol fermentation

建立了乙醇发酵耦联微藻培养系统,研究了利用酿酒酵母Saccharomyces cerevisiae乙醇发酵副产CO2为碳源,培养富含淀粉的亚心形四爿藻Tetraselmis subcordiformis,作为乙醇发酵补充原料的可行性。在连续光照条件下,间歇式培养7 d,反应器中藻细胞密度达到2.0 g/L左右,胞内淀粉含量约45%。微藻细胞收集后,经超声处理和酶法水解,葡萄糖释放量为胞内淀粉总量的71.1%。S.cerevisiae发酵微藻生物质水解液生产乙醇,其得率达到理论值的87.6%。表明乙醇发酵耦联微藻培养可行,既减少了CO2向环境的排放,又收获了富含淀粉的微藻生物质作为乙醇发酵的补充原料,节省粮食类淀粉质原料的消耗。

A system coupling ethanol fermentation with microalgae culture was developed,in which CO2 produced during ethanol fermentation was used as carbon source for the growth of Tetraselmis subcordiformis,a microalgae accumulating starch intracellularly.The biomass concentration about 2.0 g DCW/L was achieved within the photobioreactor for the batch culture of 7 days,and intracellular starch accumulation was about 45%.Furthermore,ultrasonic pretreatment and enzymatic hydrolysis were applied to the microalgae biomass,and 71.1% of the intracellular starch was converted into glucose that was fermented sequentially to ethanol by Saccharomyces cerevisiae with an ethanol yield of 87.6% of the theoretical value,indicating that the microalgae biomass could be an alternative feedstock for ethanol production to save grain consumption,and in the meantime mitigate the CO2 emission.