Converting wastes to valuable products is the main target for many kinds of research nowadays. Wastes represent an environmental problem and getting rid of it is not easy and causes pollution. Accordingly, this study offers production of the valuable enzyme β-galactosidase using rice straw and orange peel as the main medium constituents. β-galactosidase converts lactose to glucose and galactose which are simple sugars and can be fermented easily by lactose-intolerant people who represent more than 50% of the world’s population. It was produced by Lactobacillus paracasei, a series isolated from fermented milk, identified using 16S ribosomal RNA gene partial sequence and had the accession number MK852178. Plackett–Burman (PB) and Central Composite (CCD) Designs optimized the production scoring 1.683(10)⁶ U/ml with a difference five times higher than the non-optimized medium. The addition of 0.3 or 0.6% of β-galactosidase serves as a good fortification for manufacturing nutritional and therapeutic low-lactose yogurt with no significant differences in total protein, total solids, fat, and ash between control and all treatments. The chemical, rheological and sensory properties of the final produced yogurt were evaluated during storage periods up to 9 days at 5 °C. In conclusion, L. paracasei MK852178 β-galactosidase is a promising additive in manufacturing low lactose yogurt for lactose-intolerant people since it reduces the lactose content and doesn’t influence the chemical and sensory properties.

将废物转化为有价值的产品是当今许多研究的主要目标。废物是一个环境问题，摆脱它并不容易，而且会造成污染。因此，本研究提供了利用稻草和橘皮作为主要培养基成分生产有价值的酶β-半乳糖苷酶。β-半乳糖苷酶将乳糖转化为葡萄糖和半乳糖，它们是单糖，可以被占世界人口 50% 以上的乳糖不耐症人群轻松发酵。由从发酵乳中分离得到的副干酪乳酸杆菌生产，经16S核糖体RNA基因部分序列鉴定，登录号为MK852178。Plackett-Burman (PB) 和 Central Composite (CCD) 设计优化了生产得分 1.683(10)⁶ U/ml，差异是未优化培养基的五倍。添加 0.3% 或 0.6% 的 β-半乳糖苷酶可作为生产营养和治疗性低乳糖酸奶的良好强化剂，对照和所有处理之间的总蛋白质、总固体、脂肪和灰分没有显着差异。在 5°C 下长达 9 天的储存期间，对最终生产的酸奶的化学、流变和感官特性进行了评估。总之，L. paracasei MK852178 β-半乳糖苷酶是一种很有前途的添加剂，可用于为乳糖不耐症人群制造低乳糖酸奶，因为它可以降低乳糖含量并且不影响化学和感官特性。