Moghannem Saad A M, Farag Mohamed M S, Shehab Amr M, Azab Mohamed S
Al-Azhar University, Faculty of Science, Botany and Microbiology Department, Cairo, Egypt.
Al-Azhar University, Faculty of Science, Botany and Microbiology Department, Cairo, Egypt.
Braz J Microbiol. 2018 Jul-Sep;49(3):452-462. doi: 10.1016/j.bjm.2017.05.012. Epub 2018 Jan 18.
Exopolysaccharide (EPS) biopolymers produced by microorganisms play a crucial role in the environment such as health and bio-nanotechnology sectors, gelling agents in food and cosmetic industries in addition to bio-flocculants in the environmental sector as they are degradable, nontoxic. This study focuses on the improvement of EPS production through manipulation of different culture and environmental conditions using response surface methodology (RSM). Plackett-Burman design indicated that; molasses, yeast extract and incubation temperature are the most effective parameters. Box-Behnken RSM indicated that; the optimum concentration for each parameter was 12% (w/v) for molasses, 6g/L yeast extract and 30°C for incubation temperature. The most potent bacterial isolate was identified as Bacillus velezensis KY498625. After production, EPS was extracted, purified using DEAE-cellulose, identified using Fourier transform infrared (FTIR), gel permeation chromatography (GPC) and gas chromatography-mass spectroscopy (GC-MS). The result indicated that; it has molecular weight 1.14×10D consisting of glucose, mannose and galactose.
微生物产生的胞外多糖(EPS)生物聚合物在健康和生物纳米技术等环境领域发挥着关键作用,在食品和化妆品行业中作为胶凝剂,此外在环境领域作为生物絮凝剂,因为它们可降解、无毒。本研究重点在于使用响应面法(RSM)通过操纵不同的培养和环境条件来提高EPS产量。Plackett-Burman设计表明,糖蜜、酵母提取物和培养温度是最有效的参数。Box-Behnken RSM表明,每个参数的最佳浓度为:糖蜜12%(w/v)、酵母提取物6g/L和培养温度30°C。最有效的细菌分离株被鉴定为贝莱斯芽孢杆菌KY498625。生产后,提取EPS,使用DEAE-纤维素进行纯化,使用傅里叶变换红外光谱(FTIR)、凝胶渗透色谱(GPC)和气相色谱-质谱联用(GC-MS)进行鉴定。结果表明,它的分子量为1.14×10D,由葡萄糖、甘露糖和半乳糖组成。