Hubei International Scientific and Technological Cooperation Base of Traditional Fermented Foods, College of Food Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
Department of Food Science and Technology, Faculty of Agriculture, Sana'a University, Alwehdah street, P. O. Box 19509, Sana'a, Yemen.
Sci Rep. 2020 Aug 11;10(1):13527. doi: 10.1038/s41598-020-70404-4.
A novel bacterial strain of acetic acid bacteria capable of producing riboflavin was isolated from the soil sample collected in Wuhan, China. The isolated strain was identified as Gluconobacter oxydans FBFS97 based on several phenotype characteristics, biochemicals tests, and 16S rRNA gene sequence conducted. Furthermore, the complete genome sequencing of the isolated strain has showed that it contains a complete operon for the biosynthesis of riboflavin. In order to obtain the maximum concentration of riboflavin production, Gluconobacter oxydans FBFS97 was optimized in shake flask cultures through response surface methodology employing Plackett-Burman design (PBD), and Central composite design (CCD). The results of the pre-experiments displayed that fructose and tryptone were found to be the most suitable sources of carbon and nitrogen for riboflavin production. Then, PBD was conducted for initial screening of eleven minerals (FeSO, FeCl, KHPO, KHPO, MgSO, ZnSO, NaCl, CaCl, KCl, ZnCl, and AlCl.6HO) for their significances on riboflavin production by Gluconobacter oxydans strain FBFS97. The most significant variables affecting on riboflavin production are KHPO and CaCl, the interaction affects and levels of these variables were optimized by CCD. After optimization of the medium compositions for riboflavin production were determined as follows: fructose 25 g/L, tryptone 12.5 g/L, KHPO 9 g/L, and CaCl 0.06 g/L with maximum riboflavin production 23.24 mg/L.
从中国武汉采集的土壤样本中分离出一株能产核黄素的新型醋酸菌。根据几个表型特征、生化试验和 16S rRNA 基因序列鉴定，该分离株被鉴定为氧化葡萄糖酸杆菌 FBFS97。此外，该分离株的全基因组测序表明，它含有一个完整的核黄素生物合成操纵子。为了获得核黄素生产的最大浓度，通过响应面法（Plackett-Burman 设计（PBD）和中心复合设计（CCD））对氧化葡萄糖酸杆菌 FBFS97 在摇瓶培养中进行了优化。预实验结果表明，果糖和胰蛋白胨是核黄素生产最适宜的碳源和氮源。然后，通过 PBD 对 11 种矿物质（FeSO、FeCl、KHPO、KHPO、MgSO、ZnSO、NaCl、CaCl、KCl、ZnCl 和 AlCl.6HO）进行了初始筛选，以确定它们对氧化葡萄糖酸杆菌 FBFS97 生产核黄素的重要性。对核黄素生产影响最大的变量是 KHPO 和 CaCl，这些变量的相互作用和水平通过 CCD 进行了优化。优化后确定核黄素生产的最佳培养基组成为：果糖 25 g/L、胰蛋白胨 12.5 g/L、KHPO 9 g/L 和 CaCl 0.06 g/L，最大核黄素产量为 23.24 mg/L。
