Abstract

The biochemical treatment of cellulosic ethanol wastewater (CEW) is considered to be an ideal green process. To screen out the best oleaginous yeastfor the utilization of cellulosic ethanol wastewater, four oleaginous yeasts (Trichosporon cutaneum, Rhorosporidium toruloides, Cryptococcus albidus and T. coremiiforme) were compared to assess their abilities for lipid production in terms of biomass production, lipid content and lipid yield. Furthermore, thechemical oxygen demand (COD) conversion rate, COD degradation and fatty acid composition were calculated to analyze the effect of wastewaters treatment. According to the fermentation results, the highest biomass and lipid yield of T. cutaneum in CEW were 20.945 and 1.56 g/L, respectively, while the R. toruloides reached the highest lipid content (17.32%). The maximum conversion rates of T. cutaneum are 73.64 and 6.06%, respectively, in terms of conversion yield of biomass/COD and lipids/COD. The content of fatty acids showed that after six days’ fermentation, T. coremiiforme obtained the highest unsaturated fatty acid content, the content of C18:1 and C18:2 was 57.64%. This study suggests that T. cutaneum has great potential for lipid production and wastewaters treatment from cellulosic ethanol fermentation.

摘要

纤维素乙醇废水（CEW）的生化处理被认为是一种理想的绿色工艺。筛选出的最佳含油yeastfor纤维素乙醇废水的利用率，四个含油酵母（皮状丝孢，Rhorosporidium孢酵母，浅白隐球酵母和T. coremiiforme）进行比较，以评估在生物量生产，脂质含量和脂质而言其为脂质生产能力产量。此外，通过计算化学需氧量（COD）转化率、COD降解率和脂肪酸组成来分析废水处理效果。根据发酵结果，T. cutaneum 的生物量和脂质产量最高CEW 中的脂质含量分别为 20.945 和 1.56 g/L，而R. toruloides的脂质含量最高（17.32%）。就生物质/COD 和脂质/COD 的转化率而言，T. cutaneum的最大转化率分别为73.64% 和6.06%。脂肪酸含量表明，发酵6天后，T. coremiiforme获得的不饱和脂肪酸含量最高，C18:1和C18:2的含量为57.64%。这项研究表明，T. cutaneum在纤维素乙醇发酵的脂质生产和废水处理方面具有巨大潜力。