Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam, India.
Prep Biochem Biotechnol. 2013;43(7):717-34. doi: 10.1080/10826068.2013.773342.
The present study describes the usage of dried leafy biomass of mango (Mangifera indica) containing 26.3% (w/w) cellulose, 54.4% (w/w) hemicellulose, and 16.9% (w/w) lignin, as a substrate for bioethanol production from Zymomonas mobilis and Candida shehatae. The substrate was subjected to two different pretreatment strategies, namely, wet oxidation and an organosolv process. An ethanol concentration (1.21 g/L) was obtained with Z. mobilis in a shake-flask simultaneous saccharification and fermentation (SSF) trial using 1% (w/v) wet oxidation pretreated mango leaves along with mixed enzymatic consortium of Bacillus subtilis cellulase and recombinant hemicellulase (GH43), whereas C. shehatae gave a slightly higher (8%) ethanol titer of 1.31 g/L. Employing 1% (w/v) organosolv pretreated mango leaves and using Z. mobilis and C. shehatae separately in the SSF, the ethanol titers of 1.33 g/L and 1.52 g/L, respectively, were obtained. The SSF experiments performed with 5% (w/v) organosolv-pretreated substrate along with C. shehatae as fermentative organism gave a significantly enhanced ethanol titer value of 8.11 g/L using the shake flask and 12.33 g/L at the bioreactor level. From the bioreactor, 94.4% (v/v) ethanol was recovered by rotary evaporator with 21% purification efficiency.
本研究描述了利用芒果（Mangifera indica）叶干粉作为生物乙醇生产的底物，其纤维素含量为 26.3%（w/w），半纤维素含量为 54.4%（w/w），木质素含量为 16.9%（w/w）。底物采用了两种不同的预处理策略，即湿式氧化和有机溶剂法。在摇瓶同步糖化发酵（SSF）试验中，使用 1%（w/v）湿式氧化预处理的芒果叶和枯草芽孢杆菌纤维素酶和重组半纤维素酶（GH43）混合酶制剂，Zymomonas mobilis 可获得 1.21 g/L 的乙醇浓度，而 Candida shehatae 则略高（8%），乙醇产量为 1.31 g/L。采用 1%（w/v）有机溶剂法预处理的芒果叶，分别使用 Z. mobilis 和 C. shehatae 进行 SSF，乙醇产量分别为 1.33 g/L 和 1.52 g/L。在 SSF 试验中，使用 5%（w/v）有机溶剂预处理的底物，结合 C. shehatae 作为发酵生物，在摇瓶中可获得显著提高的乙醇产量，为 8.11 g/L，在生物反应器中为 12.33 g/L。从生物反应器中，通过旋转蒸发器可回收 94.4%（v/v）的乙醇，纯度为 21%。
