Abstract

The present study aimed to evaluate the lactose hydrolysis conditions from “coalho” cheese whey using β-galactosidase (β-gal) produced by Kluyveromyces lactis immobilized with sodium alginate. Three sodium alginate-based immobilization systems were evaluated (0.5, 0.7, and 1% w/v) for maximizing the immobilization yield (Y), efficiency (EM), and recovered activity (ar). The lactose hydrolysis capacity of the immobilized form of β-gal was determined, and simulated environments were used to assess the preservation of the immobilized enzyme in the gastrointestinal tract. The results showed that β-gal immobilization with 1% (w/v) sodium alginate presented the best results (EM of 66%, Y of 41%, and ar of 65%). The immobilization system maintained the highest pH stability in the range between 5.0 and 7.0, with the highest relative activity obtained under pH 5 conditions. The temperature stability was also favored by immobilization at 50 °C for 30 min was obtained a relative activity of 180.0 ± 1.37%. In 6 h, the immobilized β-gal was able to hydrolyze 46% of the initial lactose content. For the gastrointestinal simulations, around 40% of the activity was preserved after 2 h. Overall, the results described here are promising for the industrial applications of β-galactosidase from K. lactis.

摘要

本研究旨在使用乳酸克鲁维酵母产生的β-半乳糖苷酶（β-gal）评估“ coalho”干酪乳清中的乳糖水解条件用海藻酸钠固定。评估了三种基于藻酸钠的固定系统（0.5、0.7和1％w / v），以最大程度地提高固定产率（Y），效率（EM）和恢复的活性（ar）。测定固定形式的β-gal的乳糖水解能力，并使用模拟环境评估固定化酶在胃肠道中的保存。结果表明，用1％（w / v）海藻酸钠固定β-gal具有最佳效果（EM为66％，Y为41％，ar为65％）。固定化系统在5.0到7.0范围内保持了最高的pH稳定性，在pH 5的条件下获得了最高的相对活性。通过在50°C固定30分钟也获得了温度稳定性，相对活性为180.0±1.37％。在6小时内 固定化的β-gal能够水解46％的初始乳糖含量。对于胃肠道模拟，2小时后保留了约40％的活性。总体而言，此处描述的结果对于工业生产β-半乳糖苷酶很有希望克鲁维酵母。