生物共代谢动力学模型

Models of the Kinetics of Biological Co-metabolism

共代谢转化率与生长期生长基质的消耗以及在缺乏生长基质条件下生物量和/或能源物质的消耗有关.对比了早先提出的关于休眠细胞的三种共代谢动力学模型(1～3),得出三种模型在高浓度生长基质存在时具有的共同特征,并提出在生长基质存在条件下非生长基质转化的表达式,将该表达式与细胞生长表达式合并所构成的方程描述了另一个完整模型(4),它涵盖了模型1～3的特征并同时适用于休眠细胞和生长细胞的共代谢动力学研究.模型(4)描述了非生长基质的转化及生长基质和生物量的消耗,预测共代谢导致了生物维持生长所需物质和衰减速率的增加以及共代谢种群比生长速率的降低,该模型同时还包含了竞争性抑制作用的影响.

Experimental observations indicate that the rates of co-metabolic transformations are linked to the comsumption of growth substrate during growth and to the consumption of cellmass and/or energy substrate in the absence of growth substrate.Three previously proposed models (models 1 through 3) describing the kinetice of co-metabolism by resting cells are compared,models 1 to 3 are shown to converge at high concentrations of the non-growth substrate.An expression describing non-growth substrate transformation in the presence of growth substrate is proposed,and this expression is integrated with an expression or cell growth to give a single model (model 4) that encompasses models 1 to 3 and describes co-metabolism by both resting and growing cells.Model 4 couples transformation of non-growth substrate to consumption of growth substrate and biomass,and predicts that co-metabolism will result in increased maintenance requirements and decay rates,and decreased specific growth rates for a co-metabolizing population.Competitive inhibition can also be incorporated in the model