School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
Appl Biochem Biotechnol. 2012 Mar;166(6):1388-400. doi: 10.1007/s12010-011-9532-4. Epub 2012 Jan 14.
To investigate the effect of pH and temperature on the cell growth and bacteriocin production of Pediococcus acidilactici PA003, a lactic acid bacterium isolated from traditionally fermented cabbage, the kinetic behaviour of P. acidilactici PA003 was simulated in vitro during laboratory fermentations by making use of MRS broth. Firstly, primary models were developed for cell growth, glucose consumption, lactic acid and bacteriocin production for a given set of environmental conditions. Based on primary models, further study was undertaken to fit secondary models to describe the influence of temperature and pH on microbial behaviour. The models were validated successfully for all components. The results from the cell yield coefficient for lactic acid production reflected the homofermentative nature of P. acidilactici PA003. Both cell growth and bacteriocin production were very much influenced by changes in temperature and pH. The optimal condition for specific growth rate and biomass concentration was almost the same at pH 6.5 and 35 °C. At 35 °C and pH 6.1, the maximal bacteriocin activity was also achieved. The kinetic models provide useful tools for elucidating the mechanisms of temperature and pH on the kinetic behaviour of P. acidilactici PA003. The information obtained in this paper may be very useful for the selection of suitable starter cultures for a particular fermentation process and is a first step in the optimization of food fermentation processes and technology as well.
为了研究 pH 值和温度对从传统发酵白菜中分离得到的乳酸细菌植物乳杆菌 PA003 的细胞生长和细菌素产生的影响，利用 MRS 肉汤在实验室发酵中模拟了植物乳杆菌 PA003 的动力学行为。首先，为一组给定的环境条件开发了用于细胞生长、葡萄糖消耗、乳酸和细菌素生产的初步模型。基于初步模型，进一步研究了适合描述温度和 pH 值对微生物行为影响的二次模型。所有组件的模型都成功验证。乳酸生产的细胞产率系数的结果反映了植物乳杆菌 PA003 的同型发酵性质。细胞生长和细菌素生产都受到温度和 pH 值变化的很大影响。在 pH 值为 6.5 和 35°C 时，比生长速率和生物量浓度的最佳条件几乎相同。在 35°C 和 pH 值为 6.1 时，也达到了最大的细菌素活性。动力学模型为阐明温度和 pH 值对植物乳杆菌 PA003 动力学行为的影响机制提供了有用的工具。本文获得的信息对于选择特定发酵过程中合适的起始培养物可能非常有用，并且是优化食品发酵过程和技术的第一步。
