Food Science and Technology Institute, Federal University of Rio Grande do Sul State, Porto Alegre, RS, Brazil.
J Ind Microbiol Biotechnol. 2010 Feb;37(2):205-12. doi: 10.1007/s10295-009-0665-1. Epub 2009 Nov 20.
Biomass and lactic acid production by a Lactobacillus plantarum strain isolated from Serrano cheese, a microorganism traditionally used in foods and recognized as a potent probiotic, was optimized. Optimization procedures were carried out in submerged batch bioreactors using cheese whey as the main carbon source. Sequential experimental Plackett-Burman designs followed by central composite design (CCD) were used to assess the influence of temperature, pH, stirring, aeration rate, and concentrations of lactose, peptone, and yeast extract on biomass and lactic acid production. Results showed that temperature, pH, aeration rate, lactose, and peptone were the most influential variables for biomass formation. Under optimized conditions, the CCD for temperature and aeration rate showed that the model predicted maximal biomass production of 14.30 g l(-1) (dw) of L. plantarum. At the central point of the CCD, a biomass of 10.2 g l(-1) (dw), with conversion rates of 0.10 g of cell g(-1) lactose and 1.08 g lactic acid g(-1) lactose (w/w), was obtained. These results provide useful information about the optimal cultivation conditions for growing L. plantarum in batch bioreactors in order to boost biomass to be used as industrial probiotic and to obtain high yields of conversion of lactose to lactic acid.
从西班牙塞拉诺奶酪中分离出的植物乳杆菌生产生物量和乳酸，这种微生物传统上用于食品中，被认为是一种有效的益生菌，对其进行了优化。在使用奶酪乳清作为主要碳源的浸没式分批生物反应器中进行了优化程序。采用顺序实验 Plackett-Burman 设计和中心复合设计 (CCD) 来评估温度、pH 值、搅拌、通气率以及乳糖、蛋白胨和酵母提取物的浓度对生物量和乳酸生产的影响。结果表明，温度、pH 值、通气率、乳糖和蛋白胨是生物量形成的最具影响力的变量。在优化条件下，CCD 对温度和通气率的显示，该模型预测了植物乳杆菌最大的生物量生产为 14.30 g l(-1)（dw）。在 CCD 的中心点，获得了 10.2 g l(-1)（dw）的生物量，乳糖转化率为 0.10 g 细胞 g(-1)乳糖和 1.08 g 乳酸 g(-1)乳糖（w/w）。这些结果为在分批生物反应器中培养植物乳杆菌提供了有用的信息，以优化培养条件来提高生物量，用于工业益生菌，并获得高转化率的乳糖转化为乳酸。
