缺乏胺的乳球菌 (Lactococcus lactis) 用于生产食品级的酸盐
Shuangqing Zhao1, Christian Solem1
1National Food Institute, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark.
Journal of agricultural and food chemistry
|February 20, 2024
概括
饥饿的乳球菌对胺转向其新陈代谢以产生pyruvate,一个有价值的食品成分. 这种方法避免了基因改造,产生了用于抗氧化剂和黄油调味剂等应用的酸盐.
科学领域:
- 微生物学 微生物学
- 代谢工程是代谢工程.
- 食品科学 食品科学 食品科学
背景情况:
- 乳球菌 (Lactococcus lactis) 是一种安全的细菌,对乳制品发酵至关重要,主要生产乳酸.
- 基因工程可以修改L. lactis以产生其他化合物,但非遗传方法是可取的.
研究的目的:
- 探索重新连接L. lactis的新陈代谢以生产无遗传工具的pyruvate.
- 作为一种控制发酵途径的策略,研究胺剥夺.
主要方法:
- 使用了一种缺乏胺辅酶和乳酸脱酶的L. lactis菌株 (RD1M5).
- 剥夺了胺的菌株,以抑制依赖胺酸盐 (TPP) 的酸盐脱酶 (PDHc) 和α-乙酸盐合成酶 (ALS).
- 使用空气对氧气敏感的酸盐酸酶 (PFL) 失活,将新陈代谢重定向到酸盐生产.
主要成果:
- 胺饥饿有效地阻断了pyruvate代谢中的关键酶,导致pyruvate的积累.
- 在不生长的细胞和生长的细胞中实现了酸盐的产生,包括在低胺基质中,如用Florisil处理的牛奶.
- 一种衍生菌株从分泌的pyruvate中产生α-acetolactate和diacetyl,一种黄油芳香化合物.
结论:
- 通过简单的胺饥饿,可以实现L. lactis的代谢重定向以产生食品级的酸盐分泌.
- 这种非遗传方法提供了一种可持续的方法,用于生产用于抗氧化剂或风味前体的pyruvate.
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