金属离子对纤维素酶降解汽爆秸秆的影响

摘要：以汽爆秸秆为底物，分别考察添加 Fe2+、Mg2+、Cu2+和 Fe3+四种金属离子对纤维素酶解性能的影响。结果表明，金属离子的种类、用量均会影响纤维素的酶解效率。其中 Fe2+、Cu2+对纤维素降解有促进作用，当 Fe2+浓度为 0.6 mg/mL 时，对纤维素降解促进作用最明显。Mg2+和 Fe3+则会抑制纤维素酶解。考察了纤维素酶在水解过程中的吸附过程，添加 Fe2+可加快纤维素酶的吸附，促进纤维素酶与纤维素的有效结合。关键词：纤维素酶；金属离子；水解；激活；吸附Effects of Metal Ion on the Hydrolysis of Steam-exploded Straw by CellulaseLI De-yinga ， TIAN Yi-hongb ， GONG Da-chunc（a. College of Materials and Chemical Engineering ； b. college of Biological and Pharmaceutical Sciences；c. Research Institute for New Energy ， China Three Gorges University，Yichang 443002，Hubei，China）Abstract ： Effects of metal ions Fe2+、Mg2+、Cu2+and Fe3+on the enzymatic hydrolysis of steam-exploded straw were studied. Results showed that the kinds and concentrations of metal ions affected yield of enzymatic hydrolysis. Fe2+ and Cu2+ improved enzymatic hydrolysis of lignocelluloses. Fe2+ significantly increased yield of enzymatic hydrolysis when the concentration was 0.6 mg/mL. Mg2+ and Fe3+ had some inhibition on the degradation of cellulose. The adsorption process of cellulase in the hydrolysis was examined. Adding Fe2+ accelerated cellulase adsorption and formed productive binding that increases accessibility of cellulose to cellulose.Key words ： cellulase ； metal ion ； hydrolysis ； activation ； adsorption木质纤维素水解是纤维素乙醇的关键技术之一。利用纤维素酶进行纤维素水解，可以避开酸水解工艺的高温高压苛刻条件，也可以防止对生产设备的腐蚀，但其缺点是反应速度慢、生产周期长、酶成本高。因此，设法提高纤维素酶的活力可以提高转化率，降低生产成本。目前报道较多的金属离子对纤维素酶的影响基本都采纳游离酶作为考察对象，没有涉及到反应体系中的酶，对实际应用意义不大[4-8]。本讨论...