Reconstruction Of Genome Minimized Metabolic Model Of Bacillus Subtilis

The minimum life is one of the most important research topics in syntheticbiology. Minimizing a genome while at the same time maintaining an optimal growthof the cells is one of the important research objectives in metabolic engineering. Herewe propose a genome minimization method based on genome scale metabolicnetwork analysis. The metabolic network is minimized by first deleting the zero fluxreactions from flux variability analysis, and then by repeatedly calculating theoptimal growth rates after combinatorial deletion of the non-essential genes in thereduced network.Bacillus subtilis is a Gram-positive bacteria which is used in the production ofmany kinds of enzymes efficiently and safely. The recently reconstructed model isiBsu1147, including1147genes and1742reactions, which was reconstructed byTong Hao and her co-workers.In this work, for the first time, we reconstructed the in silico genome minimizedmetabolic model (GMMM) of Bacillus subtilis based on the well-reconstructedgenome-scale metabolic network model iBsu1147with the Top-down method. As theculture condition is an important factor which influences the scale of network, theGMMMs on minimum and LB medium are studied, respectively. The GMMM onminimum medium includes420genes and has the same specific growth rate withwild-type strain. The GMMM on LB medium includes395genes and its specificgrowth rate is100%of the wild-type strain.The in silico reconstruction of B. subtilis GMMMs not only provides guidancefor the design of wet experiments for minimizing genome, but also provides aplatform for the development of useful biological products and enhanced biologicalfunctions.