Comparative Study of Sulfite (SPORL), Dilute Acid and NaOH Pretreatments of Bamboo for Enzymatic Saccharification
Comparative Study of Sulfite (SPORL), Dilute Acid and NaOH Pretreatments of Bamboo for Enzymatic Saccharification
复制标题
DOI：
10.1166/jbmb.2012.1250
复制
发表时间：
2012-10-01
影响因子：
0.5
通讯作者：
Pan, Xuejun
中科院分区：
文献类型：
--
作者：
Li, Zhiqiang;Yang, Qiang;Pan, Xuejun
比较了亚硫酸盐（SPORL）、稀酸（DA）和碱（NaOH）三种预处理方法对竹材酶法糖化的预处理效果。预处理在微波加速反应器中在180 ° C下以6.25：1（v/w）的液竹比进行30 min。DA预处理的化学负荷为2%H2SO4，碱预处理的化学负荷为6%和9% NaOH，SPORL预处理的化学负荷为2- 8%Na2SO3和2- 4%H2SO4。结果表明，与其他禾本科植物不同的是，竹子由于其高密度和高木质素含量而对预处理具有抗性。在每克纤维素酶加酶量为15 FPU纤维素酶和30 IU β-葡萄糖苷酶的条件下，预处理后的竹材在48 h内水解50-60%。半纤维素的去除似乎比木质素的去除更关键的底物的酶消化率时，脱木质素是不广泛的。酸预处理对竹材半纤维素的去除率高于碱预处理。在木质素和半纤维素含量相近的情况下，SPORL底物比DA底物具有更好的消化性，这是因为少量亚硫酸盐的加入使木质素部分磺化，降低了木质素对纤维素酶的疏水性影响。SPORL预处理的其他优点包括总糖产量高，发酵抑制剂的形成有限，并产生高价值的木质素磺酸盐。
The performance of sulfite (SPORL), dilute acid (DA), and base (NaOH) pretreatments was compared in pretreating bamboo for enzymatic saccharification. The pretreatments were conducted in a microwave-accelerated reactor at 180 degrees C for 30 min with a liquor-to-bamboo ratio of 6.25:1 (v/w). Chemical loadings were 2% H2SO4 for DA pretreatment, 6 and 9% NaOH for base pretreatment, and 2-8% Na2SO3 with 2-4% H2SO4 for SPORL pretreatment (on oven-dry bamboo), respectively. Results indicated that unlike other grasses, bamboo was resistant to pretreatment due to high density and lignin content. The pretreated bamboo was hydrolyzed by 50-60% within 48 hours with an enzyme loading of 15 FPU cellulase and 30 IU beta-glucosidase per gram cellulose. The removal of hemicellulose seemed more critical to the enzymatic digestibility of a substrate than the removal of lignin when delignification was not extensive. In general, acidic pretreatments were more effective to bamboo than base pretreatments since the former removed more hemicelluloses than the latter. At similar content of lignin and hemicelluloses, SPORL substrate had better digestibility than DA substrate because the addition of small amount of sulfite made the lignin partially sulfonated, which reduced the hydrophobic impact of lignin on cellulases. Other advantages of SPORL pretreatment included high overall sugar yield, limited formation of fermentation inhibitors, and production of high-value lignosulfonate.