构建限制性条件下微生物群体生长模型时的问题

Logistic生长模型在表征营养限制性生长条件下微生物群体生长时,遇到了种种困难．该模型未能明确给出微生物群体生长的“延迟期”和“代时”两个重要生长动力学参数,也忽视了方程中参数“r”应为平均生长速率,且不具有内禀生长率性质等诸多生物学特点．采用E．coli ATCC31343,37℃液体摇瓶培养下获得的实验数据,证实了Logistic模型存在的上述局限性．通过对E．coli以葡萄糖和山梨醇共作碳源时,表现出的“二峰生长”曲线与用Logistic方程拟合结果的比较,表明适合度分析（goodness—fit test）不能作为模型是否适合的唯一判据．并对构建微生物群体生长模型的策略进行了讨论．图5参31

DIFFICULTIES IN ESTIMATING MICROBIAL GROWTH PARAMETERS BY USING LOGISTIC MODEL

Many difficulties that Logistic growth model was confronted with in describing microbial growth characteristics were discussed. An experimental result (E.coli ATCC 31343 grown in LB medium ) showed that two important growth parameters,"lag phase" and "generation time" could not be directly obtained by Logistic model, and especially the parameter "r" was, in fact, a variable value of growth rates. Unfortunately, it was defined as a constant in Logistic model that led to some misleading results in microbiology and biotechnology field. Different approaches for constructing growth models were also discussed in this paper. Fig 5, Ref 31