β-Glucosidase from novel bacteria Zobellella denitrificans VIT SB117 was isolated, and to increase the production of the enzyme, various growth parameters of the bacteria were optimized. Plackett–Burman design and response surface methodology helped determine the most significant parameters (fructose, temperature, and culture volume) resulting in a 10-fold increase in enzyme activity. The enzyme was purified and kinetics study for free and immobilized enzyme revealed K_m of 4.76 mM and 8.39 mM, K_cat of 255.02 s⁻¹ and 114.02 s⁻¹, and V_max of 4.33 mg/s and 1.25 mg/s, respectively. Enzyme characterization determined optimum substrate concentration and incubation time as 3.5 mM and 10 min respectively for the free enzyme, and 4 mM and 20 min respectively for the immobilized enzyme for maximum activity. pH 5, 45 °C incubation temperature and addition of Mg²⁺ and Mn²⁺ ions exhibited similar stimulatory effects on free and immobilized enzyme activities while Hg²⁺ ions showed strong inhibitory effects. The immobilized enzyme had negligible loss of activity after a month’s storage at 2–4 °C in acetate buffer and ~ 27.76% residual activity after 17 continuous cycles. These optimized parameters were employed for bioethanol production from lignocellulosic wastes. A total cellulose recovery of 52.77% was achieved after pretreatment. Release of ~ 57 mg/g substrate reducing sugars was achieved by enzymatic hydrolysis using immobilized cellulase enzyme complex that produced ~ 5.46 mg/ml bioethanol after 144 h of fermentation using yeast.

从新型细菌反硝化细菌VIT SB117中分离了β-葡萄糖苷酶，为了增加酶的产量，对细菌的各种生长参数进行了优化。Plackett-Burman设计和响应面方法有助于确定最重要的参数（果糖，温度和培养体积），从而使酶活性增加10倍。纯化了该酶，对游离和固定化酶的动力学研究表明K _m为4.76 mM和8.39 mM，K _cat为255.02 s ^-1和114.02 s ^-1，并且V _max分别为4.33 mg / s和1.25 mg / s。酶的特性确定了最佳的底物浓度和孵育时间，游离酶分别为3.5 mM和10分钟，固定酶的最佳底物浓度和孵育时间分别为4 mM和20分钟，以实现最大活性。pH 5、45°C的孵育温度以及添加Mg ²⁺和Mn ²⁺离子对游离和固定化酶的活性表现出相似的刺激作用，而Hg ²⁺离子显示出强大的抑制作用。固定化酶在乙酸缓冲液中于2-4°C储存一个月后，其活性损失可忽略不计，而在连续17个循环后，其残留活性约为27.76％。这些优化的参数用于从木质纤维素废物生产生物乙醇。预处理后，纤维素的总回收率为52.77％。使用固定的纤维素酶复合物通过酶促水解实现〜57 mg / g底物还原糖的释放，该复合物在使用酵母发酵144 h后产生了〜5.46 mg / ml的生物乙醇。