Paegle Longina, Ruklisha Maija
Institute of Microbiology and Biotechnology, University of Latvia, Kronvalda boulevard 4, LV-1586 Riga, Latvia.
J Biotechnol. 2003 Sep 4;104(1-3):123-8. doi: 10.1016/s0168-1656(03)00143-3.
The effect of acetate as a glucose co-substrate on growth, lysine synthesis and experimental lysine yield from carbon substrates by Corynebacterium glutamicum RC 115 was investigated. It was found that low amounts of acetate, injected with a glucose-acetate pulse into the steady-state continuous culture in bioreactor, caused a slight decrease in the specific rates of glucose uptake and bacterial growth, but a significant increase in the cell specific rate of lysine synthesis and an increase in lysine yield. In contrast, acetate injected in high amounts was followed by a drastic decrease in the values of these parameters. A strong increase in experimental lysine yield under the latter conditions was reached in the response to pyruvate addition. Therefore it was shown that acetate in low concentrations can be used as a glucose co-substrate to increase the cell specific rate of lysine synthesis and lysine yield by C. glutamicum RC 115. Pyruvate supplementation was found as a promising method to enhance lysine synthesis by bacterial cells grown in glucose-acetate media with an increased concentration of acetate.
研究了乙酸盐作为葡萄糖共底物对谷氨酸棒杆菌RC 115生长、赖氨酸合成以及从碳源底物获得的实验性赖氨酸产量的影响。结果发现，向生物反应器中的稳态连续培养物中以葡萄糖-乙酸盐脉冲形式注入少量乙酸盐，会使葡萄糖摄取比速率和细菌生长比速率略有下降，但赖氨酸合成的细胞比速率显著增加，且赖氨酸产量提高。相比之下，大量注入乙酸盐后，这些参数的值会急剧下降。在后者条件下，通过添加丙酮酸，实验性赖氨酸产量大幅提高。因此表明，低浓度的乙酸盐可作为葡萄糖共底物，以提高谷氨酸棒杆菌RC 115的赖氨酸合成细胞比速率和赖氨酸产量。发现补充丙酮酸是一种有前景的方法，可增强在乙酸盐浓度增加的葡萄糖-乙酸盐培养基中生长的细菌细胞的赖氨酸合成。
