叔丁醇介质体系中R.oryzae细胞催化大豆油制备生物柴油的研究

利用产胞内脂肪酶的微生物全细胞代替脂肪酶用于生物柴油的制备是降低酶法制备生物柴油成本的一条可行途径,近年来成为酶法制备生物柴油领域的研究热点。本论文探讨在叔丁醇介质体系下,以固定化R.oryzae全细胞作为催化剂催化大豆油制备生物柴油的可行性;考察叔丁醇用量、甲醇用量、缓冲液pH、初始含水量、菌体干重以及反应温度等因素对生物柴油得率的影响。在优化反应条件下,以大豆油为原料,反应24h生物柴油得率可达70%左右。比较了固定化R.oryzae全细胞在叔丁醇介质体系与无溶剂体系两种体系下的稳定性。结果表明,叔丁醇介质体系下R.oryzae全细胞回用稳定性显著提高。

R.oryzae whole cell-catalyzed methanolysis of soybean oil for biodiesel production in tert-butanol system

Utilizing whole cell biocatalyst instead of free or immobilized enzyme is a potential way to reduce the cost of catalyst in lipase-catalyzed biodiesel production. Rhizopus oryzae （R.oryzae） IFO4697 whole cell immobilized within biomass support particles （BSPs） is used for the methanolysis of soybean oil for biodiesel production in this paper. Tert-butanol is demonstrated to be an ideal reaction medium, in which the negative effects caused by substrate methanol could be eliminated effectively. Parameters that may influence the biodiesel yield are studied systematically, including tert-butanol to oil ratio （v/v）, methanol to oil ratio （mol/mol）, buffer pH, initial water content （based on oil weight）, dry biomass of the whole cell, reaction temperature and rotate speed of the shaker. When methanolysis using BSP-immobilized cells is carried out in tert-butanol system, the highest biodiesel yield after 24 hours is about 70%. The stability of the immobilized cells in tert-butanol system has been improved significantly compared to that in solvent free system.