Mitrea Laura, Vodnar Dan Cristian
Faculty of Food Science and Technology, Institute of Life Sciences, University of Agricultural Sciences and Veterinary Medicine, Calea Mănăștur 3-5, 400372 Cluj-Napoca, Romania.
Pathogens. 2019 Dec 11;8(4):293. doi: 10.3390/pathogens8040293.
Despite being a well-known human pathogen, plays a significant role in the biotechnology field, being considered as a microbial cell factory in terms of valuable chemical biosynthesis. In this work, DSMZ 2026 was investigated for its potential to biosynthesize 1,3-propanediol (PDO) and 2,3-butanediol (BDO) during batch fermentation under controlled and uncontrolled pH levels. The bacterial strain was cultivated at a bioreactor level, and it was inoculated in 2 L of specific mineral broth containing 50 g/L of glycerol as the main carbon source. The process was conducted under anaerobic conditions at 37 °C and 180 RPM (rotations per minute) for 24 h. The effect of pH oscillation on the biosynthesis of PDO and BDO was investigated. Samples were taken every 3 h and specific tests were performed: pH measurement, main substrate consumption, PDO and BDO production. The cell morphology was analyzed on both solid and liquid media. After 24 h of cultivation, the maximum concentrations of PDO and BDO were 28.63 ± 2.20 g/L and 18.10 ± 1.10 g/L when the pH value was maintained at 7. Decreased concentrations of PDO and BDO were achieved (11.08 ± 0.14 g/L and 7.35 ± 0.00 g/L, respectively) when the pH level was not maintained at constant values. Moreover, it was identified the presence of other metabolites (lactic, citric, and succinic acids) in the cultivation media at the beginning of the process, after 12 h and 24 h of cultivation.
尽管它是一种知名的人类病原体，但在生物技术领域发挥着重要作用，在有价值的化学生物合成方面被视为微生物细胞工厂。在这项工作中，研究了DSMZ 2026在受控和不受控pH水平下分批发酵过程中生物合成1,3 - 丙二醇（PDO）和2,3 - 丁二醇（BDO）的潜力。该细菌菌株在生物反应器水平上进行培养，并接种到2 L含有50 g/L甘油作为主要碳源的特定矿物肉汤中。该过程在37°C和180转/分钟的厌氧条件下进行24小时。研究了pH振荡对PDO和BDO生物合成的影响。每3小时取样并进行特定测试：pH测量、主要底物消耗、PDO和BDO产量。在固体和液体培养基上分析细胞形态。培养24小时后，当pH值保持在7时，PDO和BDO的最大浓度分别为28.63±2.20 g/L和18.10±1.10 g/L。当pH水平未保持恒定值时，PDO和BDO的浓度降低（分别为11.08±0.14 g/L和7.35±0.00 g/L）。此外，在培养过程开始时、培养12小时和24小时后，在培养基中鉴定出其他代谢产物（乳酸、柠檬酸和琥珀酸）的存在。
