The paper is devoted to developing a mathematical model of nutrient-dependent bacterial growth, modified by incorporating a time delay effect. The model is formalized by an initial-boundary value problem for a system of reaction-diffusion nonlinear partial differential equations, taking into account the time lag between nutrient consumption by bacteria and their subsequent reproduction. A computational scheme based on the implicit finite difference method was constructed. The numerical algorithm was supplemented with a stochastic procedure of deformation providing naturalistic growth patterns of bacterial colonies. A series of computational experiments are conducted to explore the spatio-temporal distributions of bacterial biomass concentration depending on the lag effect. Computational experiments allow us to reveal the specification of the dependence of the bacterial growth rate on the time delay control parameter.