RT Journal Article SR Electronic T1 Integrated biphasic growth rate, gene expression, and cell-size homeostasis behaviour of single B. subtilis cells JF bioRxiv FD Cold Spring Harbor Laboratory SP 510925 DO 10.1101/510925 A1 Niclas Nordholt A1 Johan H. van Heerden A1 Frank J. Bruggeman YR 2019 UL http://biorxiv.org/content/early/2019/04/18/510925.abstract AB The growth rate of single bacterial cells is continuously disturbed by random uctuations in biosynthesis rates and by deterministic cell-cycle events, such as division, genome duplication, and septum formation. It is not understood whether, and how, bacteria reject these disturbances. Here we quantified growth and constitutive protein expression dynamics of single Bacillus subtilis cells, as a function of cell-cycle-progression. Variation in birth size and growth rate, resulting from unequal cell division, is largely compensated for when cells divide again. We analysed the cell-cycle-dynamics of these compensations and found that both growth and protein expression exhibited biphasic behaviour. During a first phase of variable duration, the absolute rates were approximately constant and cells behaved as sizers. In the second phase, rates increased and growth behaviour exhibited characteristics of a timer-strategy. This work shows how cell-cycle-dependent rate adjustments of biosynthesis and growth are integrated to compensate for physiological disturbances caused by cell division.