Abstract

Biogeochemical reaction modeling (BGRM) is a computational framework that couples the simulation of microbial metabolism with the simulation of chemical reactions. BGRM simulates chemical reactions using the classical approaches of geochemical reaction modeling. Specifically, it builds on the equilibrium simulation of chemical speciation, and applies kinetic or equilibrium modeling approach to redox reaction, mineral precipitation and dissolution, and other chemical reactions. BGRM simulates the metabolism of microbial groups in terms of the rates of microbial respiration/fermentation, growth, and maintenance. It describes microbial rates using rate laws that consider the availability of electron donors, acceptors, and growth nutrients, the thermodynamics of the environment, and the energetics of microbial metabolism. By capturing the thermodynamics and kinetics of chemical and microbial reactions, BGRM can be applied to assess the habitability and potential metabolic activit ies of natural environments, and to predict the dynamics of microbial populations and environmental chemistry. By simulating simultaneously chemical and microbial reactions, BGRM can also be applied to investigate the interactions among different microbial groups, and between microbes and their environment.