Microbial growth control: integrating protein abundance and activity.

Understanding the governing principles of microbial growth control is central to fundamental microbiology, biotechnology, and systems biology. Recent quantitative studies have highlighted the pivotal role of proteome allocation in microbial growth control. Rather than simply maximizing growth, microbial cells dynamically adjust their resource allocation strategies to balance multiple physiological traits due to the fundamental constraint of trade-offs. Moreover, beyond resource allocation, which largely involves 'abundance control', recent studies have revealed another critical regulatory layer of microbial growth - 'activity control', such as modulations of ribosomal elongation rates, metabolic enzyme efficiency, and the fraction of actively translating ribosomes. Integrating these quantitative principles is expected to advance a comprehensive understanding of how distinct microbial physio-types emerge across diverse ecological niches and to further guide the rational design of synthetic biology.