Elsababty Zainab E, Abdel-Aziz Samir H, Ibrahim Atef M, Guirgis Adel A, Dawwam Ghada E
Botany and Microbiology Department, Faculty of Science, Benha University, Benha, 13518, Egypt.
Microbial Biotechnology Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), University of Sadat City, P.O. Box 79, Menoufia, Egypt.
J Genet Eng Biotechnol. 2022 Feb 22;20(1):34. doi: 10.1186/s43141-022-00317-4.
Cellulose is the most prevalent biomass and renewable energy source in nature. The hydrolysis of cellulosic biomass to glucose units is essential for the economic exploitation of this natural resource. Cellulase enzyme, which is largely generated by bacteria and fungus, is commonly used to degrade cellulose. Cellulases are used in a variety of industries, including bioethanol manufacturing, textiles, detergents, drugs, food, and paper. As part of our quest to find an efficient biocatalyst for the hydrolysis of cellulosic biomass, we describe the amplification, cloning, and sequencing of cellulase (cel9z) from Bacillus licheniformis strain Z9, as well as the characterization of the resulting enzyme.
Cellulase was partially purified from B. licheniformis strain Z9 using (NH)SO precipitation and Sephadex G-100 gel column chromatography with 356.5 U/mg specific activity, 2.1-purification fold, and 3.07 % yield. The nucleotide sequence of the cellulase gene was deposited to the GenBank, B. licheniformis strain Z9 cellulase (cel9z) gene, under accession number MK814929. This corresponds to 1453 nucleotides gene and encodes for a protein composed of 484 amino acids. Comparison of deduced amino acids sequence to other related cellulases showed that the enzyme cel9z can be classified as a glycoside hydrolase family 9. SDS-PAGE analysis of the purified enzyme revealed that the molecular mass was 54.5 kDa. The optimal enzyme activity was observed at pH 7.4 and 30 °C. The enzyme was found to be strongly inhibited by Mg and Na, whereas strongly activated by Fe, Cu, and Ca.
B. licheniformis strain Z9 and its cellulase gene can be further utilized for recombinant production of cellulases for industrial application.
纤维素是自然界中最普遍的生物质和可再生能源。将纤维素生物质水解为葡萄糖单元对于这种自然资源的经济开发至关重要。纤维素酶主要由细菌和真菌产生，通常用于降解纤维素。纤维素酶被用于多种行业，包括生物乙醇生产、纺织、洗涤剂、药品、食品和造纸。作为我们寻找纤维素生物质水解高效生物催化剂的一部分工作，我们描述了地衣芽孢杆菌Z9菌株纤维素酶（cel9z）的扩增、克隆和测序，以及所得酶的特性。
使用硫酸铵沉淀和Sephadex G - 100凝胶柱色谱从地衣芽孢杆菌Z9菌株中部分纯化纤维素酶，其比活性为356.5 U/mg，纯化倍数为2.1，产率为3.07%。纤维素酶基因的核苷酸序列已存入GenBank，登录号为MK814929，即地衣芽孢杆菌Z9菌株纤维素酶（cel9z）基因。该基因对应1453个核苷酸，编码一个由484个氨基酸组成的蛋白质。将推导的氨基酸序列与其他相关纤维素酶进行比较表明，cel9z酶可归类为糖苷水解酶家族9。纯化酶的SDS - PAGE分析显示其分子量为54.5 kDa。在pH 7.4和30°C时观察到最佳酶活性。发现该酶受到镁离子和钠离子的强烈抑制，而受到铁离子、铜离子和钙离子的强烈激活。
地衣芽孢杆菌Z9菌株及其纤维素酶基因可进一步用于纤维素酶的重组生产以用于工业应用。
