Choi Nakyung, Lee Jeom-Sig, Kwak Jieun, Lee Junsoo, Kim In-Hwan
Department of Food and Nutrition, Korea University.
J Oleo Sci. 2016 Nov 1;65(11):913-921. doi: 10.5650/jos.ess16092. Epub 2016 Oct 12.
A two-step enzymatic transesterification process in a solvent-free system has been developed as a novel approach to the production of biodiesel using acid oil from rice bran oil soapstock. The acid oil consisted of 53.7 wt% fatty acids, 2.4 wt% monoacylglycerols, 9.1 wt% diacylglycerols, 28.8 wt% triacylglycerols, and 6.0 wt% others. Three immobilized lipases were evaluated as potential biocatalysts, including Novozym 435 from Candida antarctica, Lipozyme RM IM from Rhizomucor miehei, and Lipozyme TL IM from Thermomyces lanuginosus. The effects of molar ratio of acid oil to ethanol, temperature, and enzyme loading were investigated to determine the optimum conditions for the transesterification with the three immobilized lipases. The optimum conditions of the three immobilized lipases were a molar ratio of 1:5 (acid oil to ethanol), the temperature range of 30-40°C, and the enzyme loading range of 5-10%. The two-step transesterification was then conducted under the optimum conditions of each lipase. The stepwise use of Novozym 435 and Lipozyme TL IM or Lipozyme RM IM and Lipozyme TL IM resulted in similar or higher levels of yield to the individual lipases. The maximum yields obtained in both stepwise uses were ca. 92%.
已开发出一种在无溶剂体系中的两步酶促酯交换过程，作为一种利用米糠油皂脚中的酸性油生产生物柴油的新方法。该酸性油由53.7 wt%的脂肪酸、2.4 wt%的单酰甘油、9.1 wt%的二酰甘油、28.8 wt%的三酰甘油和6.0 wt%的其他成分组成。评估了三种固定化脂肪酶作为潜在的生物催化剂，包括来自南极假丝酵母的诺维信435、来自米黑根毛霉的Lipozyme RM IM和来自嗜热栖热菌的Lipozyme TL IM。研究了酸性油与乙醇的摩尔比、温度和酶负载量的影响，以确定三种固定化脂肪酶进行酯交换反应的最佳条件。三种固定化脂肪酶的最佳条件为摩尔比1:5（酸性油与乙醇）、温度范围30 - 40°C和酶负载量范围5 - 10%。然后在每种脂肪酶的最佳条件下进行两步酯交换反应。分步使用诺维信435和Lipozyme TL IM或Lipozyme RM IM和Lipozyme TL IM得到的产率与单独使用脂肪酶时相似或更高。两种分步使用方法获得的最大产率约为92%。
