Grimaldi J, Collins C H, Belfort G
Howard P. Isermann Dept. of Chemical and Biological Engineering, Center for Biotechnology and Interdisciplinary Studies, RPI, Troy, NY, 12180-3590.
Biotechnol Prog. 2014 Mar-Apr;30(2):324-31. doi: 10.1002/btpr.1876. Epub 2014 Jan 30.
To overcome the main challenges facing alcohol-based biofuel production, we propose an alternate simplified biofuel production scheme based on a cell-free immobilized enzyme system. In this paper, we measured the activity of two tetrameric enzymes, a control enzyme with a colorimetric assay, β-galactosidase, and an alcohol-producing enzyme, alcohol dehydrogenase, immobilized on multiple surface curvatures and chemistries. Several solid supports including silica nanoparticles (convex), mesopourous silica (concave), diatomaceous earth (concave), and methacrylate (concave) were examined. High conversion rates and low protein leaching was achieved by covalent immobilization of both enzymes on methacrylate resin. Alcohol dehydrogenase (ADH) exhibited long-term stability and over 80% conversion of aldehyde to alcohol over 16 days of batch cycles. The complete reaction scheme for the conversion of acid to aldehyde to alcohol was demonstrated in vitro by immobilizing ADH with keto-acid decarboxylase free in solution.
为了克服基于酒精的生物燃料生产面临的主要挑战，我们提出了一种基于无细胞固定化酶系统的简化生物燃料生产方案。在本文中，我们测定了两种四聚体酶的活性，一种是用比色法测定活性的对照酶β-半乳糖苷酶，另一种是产酒精的酶乙醇脱氢酶，它们被固定在多种表面曲率和化学性质的载体上。研究了几种固体载体，包括二氧化硅纳米颗粒（凸面）、介孔二氧化硅（凹面）、硅藻土（凹面）和甲基丙烯酸酯（凹面）。通过将两种酶共价固定在甲基丙烯酸酯树脂上，实现了高转化率和低蛋白渗漏。乙醇脱氢酶（ADH）表现出长期稳定性，在16天的分批循环中，醛向酒精的转化率超过80%。通过将ADH与溶液中游离的酮酸脱羧酶固定在一起，在体外证明了酸转化为醛再转化为酒精的完整反应方案。
