College of Light Industry and Food Engineering, Guangxi University, Nanning 530004, China.
National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning 530004, China.
Carbohydr Polym. 2021 Aug 1;265:118110. doi: 10.1016/j.carbpol.2021.118110. Epub 2021 Apr 24.
Because of its excellent stability, non-toxicity, biodegradability and unique rheology, welan gum can be widely used in various fields, such as petroleum, biomedicine and food products. In this study, a high-yield mutant strain FM01-S09 was screened through two rounds of UV mutagenesis. Remarkably, the production of welan gum could be further increased by adding 4 mM NaCl at 32 h fermentation, reaching 30.12 ± 0.25 g/L (28.66% higher than no adding), and the NaCl-WG solution had stronger structural, impact resistance, and temperature resistance than HO-WG and WG solutions. Furthermore, the mechanism by which NaCl promotes welan gum synthesis was also investigated. It was found that cell membrane characteristics, intracellular microenvironment makeup, and key enzyme gene expression levels were significantly altered in different fermentation stages. Therefore, the addition of NaCl could effectively promote the growth and fermentation performance of Sphingomonas sp., providing a novel strategy for cost-effective welan gum production.
由于其优异的稳定性、低毒性、可生物降解性和独特的流变性，韦兰胶可以广泛应用于石油、生物医药和食品等各个领域。本研究通过两轮 UV 诱变筛选出高产突变株 FM01-S09。值得注意的是，在 32 h 发酵时添加 4 mM NaCl 可进一步提高韦兰胶的产量，达到 30.12±0.25 g/L（比不添加时提高了 28.66%），并且 NaCl-WG 溶液的结构、抗冲击性和耐热性均强于 HO-WG 和 WG 溶液。此外，还研究了 NaCl 促进韦兰胶合成的机制。结果发现，不同发酵阶段细胞的膜特性、细胞内微环境组成以及关键酶基因表达水平均发生了显著变化。因此，添加 NaCl 可以有效促进鞘氨醇单胞菌的生长和发酵性能，为经济高效生产韦兰胶提供了一种新策略。
