低能氮离子注入诱变选育高产结冷胶菌株的研究

Breeding of gellan gum-producing bacteria by low energy N^+ ion implantation

结冷胶是由伊乐假单胞杆菌生成的具有重要商业价值的微生物胞外多糖。本研究为了提高伊乐假单孢菌的产结冷胶水平,采用低能氮离子注入的方法选育高产菌株。经过初筛和复筛得到一株高产结冷胶菌株Pseudomonas elodea A3-5。该菌株传代稳定,生长迅速,在7 L发酵罐内生长状态优于出发菌株,分子量和品质都较高,分批发酵结冷胶产量达到16.5g/L,较出发菌株明显提高了25%。

Gellan gum is a kind of microbial exopolysaccharides with great commercial value produced by Pseudomonas elodea. In order to increase gellan gum production, low-energy N＋ ion beam implantation was used to explore a mutant strain producing a high level of gellan gum. After screening, the high producing mutant A3-5 was isolated, which exhibited better properties and increased molecular weight. Mutant A3-5 grew much faster and subcultured stably in 7 L fermentor than the wild strain. The maximal geUan gum production in batch fermentation by A3-5 was 16.53 g/L, 2596 higher than that of the wild strain.