Fujikawa Hiroshi, Munakata Kanako, Sakha Mohammad Z
Laboratory of Veterinary Public Health, Faculty of Agriculture Tokyo University of Agriculture and Technology.
Biocontrol Sci. 2014;19(2):61-71. doi: 10.4265/bio.19.61.
A novel competition model for describing bacterial growth in mixed culture was developed in this study. Several model candidates were made with our logistic growth model that precisely describes the growth of a monoculture of bacteria. These candidates were then evaluated for the usefulness in describing growth of two competing species in mixed culture using Staphylococcus aureus, Escherichia coli, and Salmonella. Bacterial cells of two species grew at initial doses of 10(3), 10(4), and 10(5) CFU/g at 28ºC. Among the candidates, a model where the Lotka-Volterra model, a general competition model in ecology, was incorporated as a new term in our growth model was the best for describing all types of growth of two competitors in mixed culture. Moreover, the values for the competition coefficient in the model were stable at various combinations of the initial populations of the species. The Baranyi model could also successfully describe the above types of growth in mixed culture when it was coupled with the Gimenez and Dalgaard model. However, the values for the competition coefficients in the competition model varied with the conditions. The present study suggested that our model could be a basic model for describing microbial competition.
本研究开发了一种用于描述混合培养中细菌生长的新型竞争模型。我们利用精确描述单一培养细菌生长的逻辑斯蒂增长模型构建了几个模型候选者。然后使用金黄色葡萄球菌、大肠杆菌和沙门氏菌评估这些候选者在描述混合培养中两种竞争物种生长方面的实用性。两种细菌细胞在28℃下以10³、10⁴和10⁵CFU/g的初始剂量生长。在这些候选者中，将生态学中的通用竞争模型——洛特卡-沃尔泰拉模型作为新项纳入我们的生长模型的那个模型，最适合描述混合培养中两种竞争者的所有类型生长。此外，该模型中竞争系数的值在物种初始种群的各种组合下是稳定的。当巴拉尼模型与希门尼斯和达尔加德模型结合时，也能成功描述混合培养中的上述生长类型。然而，竞争模型中竞争系数的值随条件而变化。本研究表明，我们的模型可能是描述微生物竞争的基础模型。
