On the intrinsic constraint of bacterial growth rate: M. tuberculosis’s view of the protein translation capacity

Abstract

In nature, the maximal growth rates vary widely among different bacteria species. Fast-growing bacteria species such as Escherichia coli can have a shortest generation time of 20 min. Slow-growing bacteria species are perhaps best known for Mycobacterium tuberculosis, a human pathogen with a generation time being no less than 16 h. Despite of the significant progress made on understanding the pathogenesis of M. tuberculosis, we know little on the origin of its intriguingly slow growth. From a global view, the intrinsic constraint of the maximal growth rate of bacteria remains to be a fundamental question in microbiology. In this review, we analyze and discuss this issue from the angle of protein translation capacity, which is the major demand for cell growth. Based on quantitative analysis, we propose four parameters: rRNA chain elongation rate, abundance of RNA polymerase engaged in rRNA synthesis, polypeptide chain elongation rate, and active ribosome fraction, which potentially limit the maximal growth rate of bacteria. We further discuss the relation of these parameters with the growth rate for M. tuberculosis as well as other bacterial species. We highlight future comprehensive investigation of these parameters for different bacteria species to understand how bacteria set their own specific growth rates.

Keywords:

• Bacterial growth rate
• Mycobacterium tuberculosis
• rRNA chain elongation rate
• fraction of RNA polymerase engaged in rRNA synthesis
• polypeptide chain elongation rate
• active ribosome fraction

Acknowledgements

We are grateful to members in Professor Terence Hwa’s lab (UCSD, US) for useful discussion and inspiration during various stages of the conceptualization of this work.

Disclosure statement

The authors report no declarations of interest.

Additional information

Funding

This research was supported by the National Natural Science Foundation of China [No. 31700039 to MZ; No. 31700089 to XD] and the start-up funding of central china normal university. MZ and XD specially thank the funding support from the Institute of Science and Technology Development in Central China Normal University.