Botany and Microbiology Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo 11884, Egypt.
Department of Biology, College of Science, Imam Mohammad Ibn Saud Islamic University, Riyadh 11623, Saudi Arabia.
J Microbiol Biotechnol. 2024 Jan 28;34(1):207-223. doi: 10.4014/jmb.2309.09023. Epub 2023 Oct 18.
The efficacy of 40 bacterial isolates obtained from hot spring water samples to produce cellulase enzymes was investigated. As a result, the strain F3, which was identified using traditional and molecular methods, was selected as the most potent for cellulase production. Optimization was carried out using one-factor-at-a-time (OFAT) and BOX-Behnken Design to detect the best conditions for the highest cellulase activity. This was accomplished after an incubation period of 24 h at 45°C and pH 8, with an inoculum size of 1% (v/v), 5 g/l of peptone as nitrogen source, and 7.5 g/l of CMC. Moreover, the best concentration of ammonium sulfate for cellulase enzyme precipitation was 60% followed by purification using a dialysis bag and Sephadex G-100 column chromatography to collect the purified enzyme. The purified cellulase enzyme was characterized by 5.39-fold enrichment, with a specific activity of 54.20 U/mg and a molecular weight of 439 kDa. There were 15 amino acids involved in the purified cellulase, with high concentrations of 160 and 100 mg/l for glycine and proline respectively. The highest stability and activity of the purified cellulase was attained at pH 7 and 50°C in the presence of 150 ppm of CaCl, NaCl, and ZnO metal ions. Finally, the biopolishing activity of the cellulase enzyme, as indicated by weight loss percentages of the cotton fabric, was dependent on concentration and treatment time. Overall, the thermotolerant F3 strain has the potential to provide highly stable and highly active cellulase enzyme for use in biopolishing of cotton fabrics.
从温泉水样中获得的 40 个细菌分离株的产纤维素酶活性进行了研究。结果表明，通过传统和分子方法鉴定的菌株 F3 是产纤维素酶的最有效菌株。使用单因素实验（OFAT）和 Box-Behnken 设计进行优化，以检测最高纤维素酶活性的最佳条件。在 45°C 和 pH8 下孵育 24 小时，接种量为 1%（v/v），以蛋白胨为氮源 5g/L，CMC 为 7.5g/L，达到最佳条件。此外，用于纤维素酶沉淀的最佳硫酸铵浓度为 60%，然后使用透析袋和 Sephadex G-100 柱层析进行纯化，以收集纯化的酶。纯化的纤维素酶经 5.39 倍富集，比活力为 54.20U/mg，分子量为 439kDa。纯化的纤维素酶涉及 15 个氨基酸，其中甘氨酸和脯氨酸的浓度分别为 160mg/L 和 100mg/L。在存在 150ppm CaCl、NaCl 和 ZnO 金属离子的情况下，纯化的纤维素酶在 pH7 和 50°C 时具有最高的稳定性和活性。最后，纤维素酶的生物抛光活性，如棉织物失重百分比所示，取决于浓度和处理时间。总的来说，耐热菌株 F3 具有提供高稳定性和高活性纤维素酶用于棉织物生物抛光的潜力。
