通过pH控制发酵通过Gluconobacter oxydans合成和物理化学分析来自马尔托德克斯的德克斯
Seung-Min Baek1, Bo-Ram Park1, Legesse Shiferaw Chewaka1
1Fermentation Research Department, National Institute of Agricultural Science, RDA, Jeonju 54875, Republic of Korea.
Foods (Basel, Switzerland)
|January 11, 2025
概括
为Gluconobacter oxydans发酵优化pH条件可以增强德克斯的产生. 这项研究发现pH4.5产生了最高粘度的德克斯,适用于缓慢消化碳水化合物和代谢性疾病管理.
科学领域:
- 生物技术和工业微生物学
- 食品科学与技术 食品科学与技术
- 生物化学 生物化学
背景情况:
- 德克斯是一种外聚糖 (EPS),在食品和药品中具有多种应用.
- 莱可诺斯托克 (Leuconostoc mesenteroides) 是主要的生产者,但Gluconobacter oxydans可以通过德克斯酶从德克斯中合成德克斯.
研究的目的:
- 研究发酵器条件,特别是pH,在生物转化过程中对G. oxydans生长和右合成的影响.
- 在不同的pH条件下评估德克斯的特性,包括粘度,分子量和水解速率.
主要方法:
- 在不同的pH条件下 (不受控制,pH4.5,pH5.0) 在发酵器中培养G. oxydans.
- 细胞密度的测量 (O.D. 在600nm) 和流动特性 (粘度) 的分析,以评估德克斯的生产.
- 使用1H-NMR进行结构确认和评估对葡萄糖的水解速率.
主要成果:
- 最佳的细胞密度和最高的乳粘度 (30.99 mPa·s) 在pH值4.5.5下得到实现.
- 1H-NMR证实了α-1,6糖化键的存在,其分子量分布根据pH值从1.3×10^3Da到5.1×10^4Da不等.
- 在pH4.5下产生的德克斯呈现出最慢的水解率到葡萄糖 (53.96%),表明消化速度较慢.
结论:
- pH显著影响G. oxydans的生长,酶活性,以及随后的德克斯生产和特征.
- pH4.5条件是生产具有可取性质的德克斯的最佳条件,可作为缓慢消化的碳水化合物用于应用.
- 这种pH值优化的德克斯具有糖分调节和减轻糖尿病等慢性代谢疾病的潜力.
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