Asian Center for Environmental Research, Meisei University, 2-1-1 Hodokubo, Hino-shi, Tokyo 191-8506, Japan.
J Biosci Bioeng. 2010 Oct;110(4):453-8. doi: 10.1016/j.jbiosc.2010.05.002. Epub 2010 Jun 4.
In this study, the effect and the optimum pretreatment condition of corncobs using low strength of H2SO4 were investigated, in which H2SO4 was used to improve the enzymatic digestibility of corncobs for saccharification without degradation of sugars released. The optimum pretreatment condition was found to be the addition of 0.5% (vol./vol.) H2SO4 and autoclaving at 122°C for 20 min. Under this condition, the structural integrity of corncob was altered to make cellulose microfibrils more accessible for cellulase enzymes, and the enzymatic digestion of corncobs could be significantly enhanced. A high yield of sugar, 80% (wt./wt.), could be obtained at a low enzyme dosage of 0.024 g enzymes/g cobs, when pretreated. As a result, the ethanol production was obviously improved by the pretreatment, i.e., the ethanol yield of 77% (wt./wt.) was obtained within 36 h in the SSF fermentation using Saccharomyces cerevisiae NBRC2114.
在这项研究中，我们考察了使用低浓度 H2SO4 对玉米芯的作用和最佳预处理条件，用 H2SO4 来提高玉米芯的酶解糖化效率，而不降解所释放的糖。我们发现最佳预处理条件为添加 0.5%（体积/体积）的 H2SO4 并在 122°C 下高压灭菌 20 分钟。在此条件下，玉米芯的结构完整性发生改变，使纤维素微纤维更易于被纤维素酶接触，从而显著提高了玉米芯的酶解效率。预处理后，在低酶用量（0.024 g 酶/g 玉米芯）下可获得 80%（质量/质量）的高糖产率。结果表明，预处理明显提高了乙醇的产量，即在使用酿酒酵母 NBRC2114 的固态发酵中，36 小时内乙醇的产率达到了 77%（质量/质量）。
