Szijártó Nóra, Szengyel Zsolt, Lidén Gunnar, Réczey Kati
Department of Agricultural Chemical Technology, Budapest University of Technology and Economics, Budapest, Hungary.
Appl Biochem Biotechnol. 2004 Spring;113-116:115-24. doi: 10.1385/abab:113:1-3:115.
An economic process for the enzymatic hydrolysis of cellulose would allow utilization of cellulosic biomass for the production of easily fermentable low-cost sugars. New and more efficient fermentation processes are emerging to convert this biologic currency to a variety of commodity products with a special emphasis on fuel ethanol production. Since the cost of cellulase production currently accounts for a large fraction of the estimated total production costs of bioethanol, a significantly less expensive process for cellulase enzyme production is needed. It will most likely be desirable to obtain cellulase production on different carbon sources-including both polymeric carbohydrates and monosaccharides. The relation between enzyme production and growth profile of the microorganism is key for designing such processes. We conducted a careful characterization of growth and cellulase production by the soft-rot fungus Trichoderma reesei. Glucose-grown cultures of T. reesei Rut-C30 were subjected to pulse additions of Solka-floc (delignified pine pulp), and the response was monitored in terms of CO2 evolution and increased enzyme activity. There was an immediate and unexpectedly strong CO2 evolution at the point of Solka-floc addition. The time profiles of induction of cellulase activity, cellulose degradation, and CO2 evolution are analyzed and discussed herein.
一种用于纤维素酶促水解的经济方法将使得纤维素生物质能够被用于生产易于发酵的低成本糖类。新的且更高效的发酵工艺正在涌现，以将这种生物货币转化为各种商品，尤其侧重于燃料乙醇的生产。由于目前纤维素酶的生产成本在生物乙醇估计的总生产成本中占很大一部分，因此需要一种成本显著更低的纤维素酶生产工艺。很可能需要在包括聚合碳水化合物和单糖在内的不同碳源上实现纤维素酶的生产。酶的生产与微生物生长曲线之间的关系是设计此类工艺的关键。我们对软腐真菌里氏木霉的生长和纤维素酶生产进行了仔细的表征。用葡萄糖培养里氏木霉Rut-C30的培养物，对其进行Solka-floc（脱木质素松浆）的脉冲添加，并根据二氧化碳释放量和酶活性的增加来监测反应。在添加Solka-floc时立即出现了出乎意料的强烈二氧化碳释放。本文分析并讨论了纤维素酶活性诱导、纤维素降解和二氧化碳释放的时间曲线。
