Ramírez Nicolás, Ubilla Claudia, Campos Javiera, Valencia Francisca, Aburto Carla, Vera Carlos, Illanes Andrés, Guerrero Cecilia
School of Biochemical Engineering, Pontificia Universidad Católica de Valparaíso (PUCV), Valparaíso, Chile.
Department of Biology, Faculty of Chemistry and Biology, Universidad de Santiago de Chile (USACH), Santiago, Chile.
Bioresour Technol. 2021 Dec;341:125769. doi: 10.1016/j.biortech.2021.125769. Epub 2021 Aug 13.
The effects of the most significant operational variables on reactor performance of fed-batch and repeated fed-batch were evaluated in the lactulose production by enzymatic transgalactosylation. Feed flowrate in the fed stage (F) and fructose to lactose molar ratio (Fr/L) were the variables that mostly affected the values of lactulose yield (Y), lactulose productivity (π) and selectivity of transgalactosylation (S/). Maximum Y of 0.21 g lactulose per g lactose was obtained at 50% w/w inlet carbohydrates concentration (IC) of, 50 °C, Fr/L 8, F 1 mL⋅min, 200 IU∙g reactor enzyme load and pH 4.5. At these conditions the selectivity was 7.4, productivity was 0.71 g∙g∙hand lactose conversion was 0.66. The operation by repeated fed batch increases the efficiency of use of the biocatalysts (E) and the accumulated productivity compared to batch and fed batch operation with the same biocatalyst. E obtained was 4.13 g∙mg, 10.6 times higher than in fed-batch.
在通过酶促转半乳糖基化生产乳果糖的过程中，评估了最重要的操作变量对分批补料和重复分批补料反应器性能的影响。补料阶段的进料流速（F）和果糖与乳糖的摩尔比（Fr/L）是对乳果糖产率（Y）、乳果糖生产率（π）和转半乳糖基化选择性（S/）值影响最大的变量。在50% w/w的入口碳水化合物浓度（IC）、50°C、Fr/L为8、F为1 mL·min、200 IU∙g反应器酶负载和pH 4.5的条件下，获得了每克乳糖0.21 g乳果糖的最大Y值。在这些条件下，选择性为7.4，生产率为0.71 g∙g∙h，乳糖转化率为0.66。与使用相同生物催化剂的分批和分批补料操作相比，重复分批补料操作提高了生物催化剂的使用效率（E）和累积生产率。获得的E为4.13 g∙mg，比分批补料高10.6倍。
