Bacterial growth laws and their applications

Quantitative empirical relationships between cell composition and growth rate played an important role in the early days of microbiology. Gradually, the focus of the field began to shift from growth physiology to the ever more elaborate molecular mechanisms of regulation employed by the organisms. Advances in systems biology and biotechnology have renewed interest in the physiology of the cell as a whole. Furthermore, gene expression is known to be intimately coupled to the growth state of the cell. Here, we review recent efforts in characterizing such couplings, particularly the quantitative phenomenological approaches exploiting bacterial ‘growth laws.’ These approaches point toward underlying design principles that can guide the predictive manipulation of cell behavior in the absence of molecular details.

► Bacterial gene expression is generically dependent on the growth status of the cell.
► The above dependence can be predicted quantitatively based on bacterial growth laws.
► Growth laws have several direct applications to biotechnology.
► Predict growth bistability due to intrinsic feedback without the need of regulation.
► Point to design principles for interfacing of synthetic circuitry with host physiology.