Department of Microbiology & Cell Science, University of Florida, Box 110700, Gainesville, FL 32611, USA.
Bioresour Technol. 2011 Apr;102(8):5145-52. doi: 10.1016/j.biortech.2011.02.008. Epub 2011 Feb 24.
The addition of reduced sulfur compounds (thiosulfate, cysteine, sodium hydrosulfite, and sodium metabisulfite) increased growth and fermentation of dilute acid hydrolysate of sugarcane bagasse by ethanologenic Escherichia coli (strains LY180, EMFR9, and MM160). With sodium metabisulfite (0.5mM), toxicity was sufficiently reduced that slurries of pretreated biomass (10% dry weight including fiber and solubles) could be fermented by E. coli strain MM160 without solid-liquid separation or cleanup of sugars. A 6-h liquefaction step was added to improve mixing. Sodium metabisulfite also caused spectral changes at wavelengths corresponding to furfural and soluble products from lignin. Glucose and cellobiose were rapidly metabolized. Xylose utilization was improved by sodium metabisulfite but remained incomplete after 144 h. The overall ethanol yield for this liquefaction plus simultaneous saccharification and co-fermentation process was 0.20 g ethanol/g bagasse dry weight, 250 L/tonne (61 gal/US ton).
添加还原硫化合物（硫代硫酸盐、半胱氨酸、亚硫酸氢钠和偏亚硫酸钠）可提高产乙醇大肠杆菌（LY180、EMFR9 和 MM160 菌株）对甘蔗渣稀酸水解物的生长和发酵。使用偏亚硫酸钠（0.5mM），毒性得到充分降低，未经固液分离或糖液净化，预处理生物质（包括纤维和可溶性物质在内的 10%干重）的浆料可被大肠杆菌 MM160 发酵。添加 6 小时液化步骤可改善混合。偏亚硫酸钠还会引起与糠醛和木质素可溶性产物对应的波长的光谱变化。葡萄糖和纤维二糖可迅速代谢。亚硫酸盐可改善木糖的利用，但 144 小时后仍未完全利用。这种液化+同步糖化和共发酵过程的总乙醇得率为 0.20g 乙醇/克蔗渣干重，250L/吨（61 加仑/美吨）。
