Haas Thorsten, Graf Michaela, Nieß Alexander, Busche Tobias, Kalinowski Jörn, Blombach Bastian, Takors Ralf
Institute of Biochemical Engineering, University of Stuttgart, Stuttgart, Germany.
Center for Biotechnology (CeBiTec), Bielefeld University, Bielefeld, Germany.
Front Microbiol. 2019 May 8;10:974. doi: 10.3389/fmicb.2019.00974. eCollection 2019.
The growth rate (μ) of industrially relevant microbes, such as , is a fundamental property that indicates its production capacity. Therefore, understanding the mechanism underlying the growth rate is imperative for improving productivity and performance through metabolic engineering. Despite recent progress in the understanding of global regulatory interactions, knowledge of mechanisms directing cell growth remains fragmented and incomplete. The current study investigated RNA-Seq data of three growth rate transitions, induced by different pre-culture conditions, in order to identify transcriptomic changes corresponding to increasing growth rates. These transitions took place in minimal medium and ranged from 0.02 to 0.4 h μ. This study enabled the identification of 447 genes as components of the growth modulon. Enrichment of genes within the growth modulon revealed 10 regulons exhibiting a significant effect over growth rate transition. In summary, central metabolism was observed to be regulated by a combination of metabolic and transcriptional activities orchestrating control over glycolysis, pentose phosphate pathway, and the tricarboxylic acid cycle. Additionally, major responses to changes in the growth rate were linked to iron uptake and carbon metabolism. In particular, genes encoding glycolytic enzymes and the glucose uptake system showed a positive correlation with the growth rate.
工业相关微生物（如 ）的生长速率（μ）是一项表明其生产能力的基本特性。因此，了解生长速率背后的机制对于通过代谢工程提高生产力和性能至关重要。尽管在理解全局调控相互作用方面取得了最新进展，但指导细胞生长的机制知识仍然零散且不完整。当前研究调查了由不同预培养条件诱导的三个生长速率转变的RNA测序数据，以识别与生长速率增加相对应的转录组变化。这些转变发生在基本培养基中，范围从0.02到0.4 h μ。这项研究使得能够鉴定出447个基因作为生长调节子的组成部分。生长调节子内基因的富集揭示了10个调节子对生长速率转变具有显著影响。总之，观察到中心代谢受代谢和转录活动的组合调控，这些活动协调对糖酵解、磷酸戊糖途径和三羧酸循环的控制。此外，对生长速率变化的主要反应与铁摄取和碳代谢有关。特别是，编码糖酵解酶和葡萄糖摄取系统的基因与生长速率呈正相关。
