检测大肠杆菌群体生长动力学过程4种方法的比较  

The Comparison of Four Methods Indicating the Growth Kinetics of E.coli

作　　者：赵越[1] 何秀丽[1] 张怀强[1] 高培基[1] 

机构地区：[1]山东大学微生物技术国家重点实验室,山东济南250100

出　　处：《生物数学学报》2013年第4期702-708,共7页Journal of Biomathematics

基　　金：国家自然科学基金(资助号:30870080);山东省国际科技合作项目计划(鲁科合字[2011]176号第6项)项目资助

摘　　要：用浊度测定、菌落形成数计数(CFU)、流式细胞计数(FCT),以及MTT还原测脱氢酶活力4种检测方法,测定了E.coli CVCC249群体的生长量,并通过Logistic模型、Sigmoid模型,以及正态分布方程拟合由上述生物量所表征的群体生长动力学过程曲线.结果表明,对浊度和流式检测数据,Logistic和Sigmoid方程可给出较好的拟合度,而对CFU法和脱氢酶活力检测法,仅有正态分布方程能呈现更好的拟合.通过应用有限时域向前差分的方法,消除不能增殖的休止细胞对浊度生长过程曲线的影响,以模拟菌群增殖的过程曲线.在此基础上,求得菌群生长的即时速度(advancing velocity,v_(adv))和即时速度的瞬变率,以此为据将E.coli CVCC249生长过程划分为线性增长期、指数增长期、指数减速期、线性减速期,以及衰亡期5个阶段.此外,对新的划分生长阶段的方法与经典方法的不同,以及R^2(拟合决定系数)能否作为确定模型是否拟合的唯一判据,进行了讨论.The growth of E.coli CVCC 249 culturing in shaking bottle under 37~C with LB liguid were measured by OD600~,,~~ or Colony forming units （CFU）, respectively. And the total cell numbers estimated with Flow cytometry and the dehydrogena^se enzyme activity with tile MTT assay. All the data were fitted by using the Logistic, Sigmoid, and Normal distribution equitation, which indicated that data of OD（~00~,,~ and cell counting with Flow cytometry could get better fitness 5y using the Logistic and Sigmoid function, while the data of dehydrogenase enzynm activity and CFU could get better fitness only by using the Normal distribution equi- tation. Forward Finite difference time-domain method was used to simulate the growth curve as advancing velocity. This method can remove the influence of non-proliferated resting cells on the growth curve characterized by OD600nrn. The advancing velocity and its instantaneous changing rate were calculated, which were used to divide the growth process of E.coli CVCC 249 into 5 growth phases： linear growth phase, exponential growth phase, exponential deceleration phase, linear deceleration phase, and decline phase. In addition, the difference t）etween this new method and the classic method that are used to divide the growth phase and whether the R2 can be taken as the only judgment to decide whether the used model fits the growth curve or not were discussed.

关 键 词：正态分布方程 时域向前差分 即时生长速度 生长阶段 持续生存 

分 类 号：Q93-31[生物学—微生物学]