das Neves Luiz Carlos Martins, Vitolo Michele
Department of Biochemical and Pharmaceutical Technology, University of São Paulo, School of Pharmaceutical Sciences, Av. Prof. Lineu Prestes, 580, B.16, 05508-900, São Paulo, SP, Brasil.
Appl Biochem Biotechnol. 2007 Apr;137-140(1-12):161-70. doi: 10.1007/s12010-007-9048-0.
This article aims at the evaluation of the catalytic performance of glucose oxidase (GO) (EC.1.1.3.4) for the glucose/gluconic acid conversion in the ultrafiltration cell type membrane reactor (MB-CSTR). The reactor was coupled with a Millipore ultrafiltration-membrane (cutoff of 100 kDa) and operated for 24 h under agitation of 100 rpm, pH 5.5, and 30 degrees C. The experimental conditions varied were the glucose concentration (2.5, 5.0, 10.0, 20.0, and 40.0 mM), the feeding rate (0.5, 1.0, 3.0, and 6.0/h), dissolved oxygen (8.0 and 16.0 mg/L), GO concentration (2.5, 5.0, 10.0, and 20.0 U(GO)/mL), and the glucose oxidase/catalase activity ratio (U(GO)/U(CAT))(1:0, 1:10, 1:20, and 1:30). A conversion yield of 80% and specific reaction rate of 40 x 10(-4) mmol/h x U(GO) were attained when the process was carried out under the following conditions: D =3.0/h, dissolved oxygen =16.0 mg/L, [G] =40 mM, and (U(GO)/U(CAT)) =1:20. A simplified model for explaining the inhibition of GO activity by hydrogen peroxide, formed during the glucose/gluconic acid conversion, was presented.
本文旨在评估葡萄糖氧化酶（GO）（EC.1.1.3.4）在超滤池型膜反应器（MB-CSTR）中对葡萄糖/葡萄糖酸转化的催化性能。该反应器与Millipore超滤膜（截留分子量为100 kDa）相连，在100 rpm搅拌、pH 5.5和30℃条件下运行24小时。变化的实验条件包括葡萄糖浓度（2.5、5.0、10.0、20.0和40.0 mM）、进料速率（0.5、1.0、3.0和6.0/h）、溶解氧（8.0和16.0 mg/L）、GO浓度（2.5、5.0、10.0和20.0 U(GO)/mL）以及葡萄糖氧化酶/过氧化氢酶活性比（U(GO)/U(CAT)）（1:0、1:10、1:20和1:30）。当在以下条件下进行该过程时，获得了80%的转化率和40×10⁻⁴ mmol/h×U(GO)的比反应速率：D = 3.0/h，溶解氧 = 16.0 mg/L，[G] = 40 mM，且（U(GO)/U(CAT)） = 1:20。本文提出了一个简化模型，用于解释在葡萄糖/葡萄糖酸转化过程中形成的过氧化氢对GO活性的抑制作用。
