Dataset Information

Identifying the Growth Modulon of Corynebacterium glutamicum.

ABSTRACT: The growth rate (?) of industrially relevant microbes, such as Corynebacterium glutamicum, 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-1 ?. 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.

SUBMITTER: Haas T

PROVIDER: S-EPMC6517550 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Identifying the Growth Modulon of <i>Corynebacterium glutamicum</i>.

Haas Thorsten T Graf Michaela M Nieß Alexander A Busche Tobias T Kalinowski Jörn J Blombach Bastian B Takors Ralf R

Frontiers in microbiology 20190508

The growth rate (μ) of industrially relevant microbes, such as <i>Corynebacterium glutamicum</i>, 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 inv ...[more]

PMID: 31134020

Similar Datasets

Project description:The growth rate (µ) of microbes is a fundamental property influencing its production capacity. To identify the transcriptomic changes of Corynebacterium glutamicum ATCC13032 with increasing growth rate, three transitions, induced by different pre-culture conditions, were sampled in triplicate at growth rates ranging from 0.02 to 0.4 h-1. The pre-culture conditions differed in limiting substrate (phosphate, nitrogen, carbon) and the length of the stationary phase. Samples of 2 mL were withdrawn from the bioreactor in biological triplicates and immediately centrifuged at 20000 g for 30 seconds at 4 °C. The supernatant was discarded and the remaining cell pellet was immediately flash frozen in liquid nitrogen. Total RNA was isolated from three biological replicates using RNeasy Mini Kit along with a DNase Kit (both from Qiagen). Initially RNA quality was checked by Trinean Xpose (Gentbrugge,Belgium) and Agilent RNA Nano 6000 kit on Agilent 2100 Bioanalyzer (Agilent Technologies, Böblingen, Germany). Samples contaminated with DNA were treated with DNase (Qiagen), cleaned as described above and rechecked by Xpose and Agilent Bioanalyzer. Finally RNA was free of DNA with an RNA Integrity Number (RIN) > 9 and rRNA Ratio [23s / 16s] > 1.5. Ribo-Zero rRNA Removal Kit (Bacteria) from Illumina (San Diego, CA, USA) was used to remove the ribosomal RNA molecules from the isolated total RNA. Removal of rRNA was checked by Agilent RNA Pico 6000 kit on Agilent 2100 Bioanalyzer (Agilent Technologies, Böblingen, Germany). RNA was free of detectable rRNA. TruSeq Stranded mRNA Library Prep Kit from Illumina (San Diego, CA, USA) was used to prepare cDNA libraries. The resulting cDNAs were sequenced paired end on an Illumina MiSeq system using 75 bp read length and on Illumina HiSeq 1500 system using 70 bp read length and 50 bp read length for one single sample. Through the comparison of these three datasets, each containing three biological replicates, the pre-condition independent gene expression changes could be deduced and the growth rate modulon was identified.

Project description:To ensure economic competitiveness, bioprocesses should achieve maximum productivities enabled by high growth rates (?) and equally high substrate consumption rates (qS) as a prerequisite of sufficient carbon-to-product conversion. Both traits were investigated and improved via bioprocess engineering approaches studying the industrial work horse Corynebacterium glutamicum. Standard minimal medium CGXII with glucose as sole carbon source was supplemented with complex brain-heart-infusion (BHI) or amino acid (AA) cocktails. Maximum ? of 0.67 h-1 was exclusively observed in 37 g BHI L-1 whereas only minor growth stimulation was found after AA supplementation (? = 0.468 h-1). Increasing glucose consumption rates (qGlc) were solely observed in certain dosages of BHI (1-10 g L-1), while 37 g BHI L-1 and AA addition revealed qGlc below the reference experiments. Moreover, BHI supplementation revealed Monod-type saturation kinetics of ? (KBHI = 2.73 g BHI L-1) referring to the preference of non-AAs as key boosting nutrients. ATP-demands under reference, 1 g BHI L-1, and AA conditions were nearly constant but halved in BHI concentrations above 5 g L-1 reflecting the energetic advantage of consuming complex nutrient components in addition to "simple" building blocks such as AAs. Furthermore, C. glutamicum revealed maximum biomass per carbon yields of about 18 gCDW C-mol-1 irrespective of the medium. In AA supplementation experiments, simultaneous uptake of 17 AAs was observed, maximum individual consumption rates determined, and L-asparagine and L-glutamine were distinguished as compounds with the highest consumption rates. Employment of the expanded stoichiometric model iMG481 successfully reproduced experimental results and revealed the importance of C. glutamicum's transaminase network to compensate needs of limiting AA supply. Model-based sensitivity studies attributed the highest impact on ? to AAs with high ATP and NADPH demands such as L-tryptophan or L-phenylalanine.

Dataset Information

Identifying the Growth Modulon of Corynebacterium glutamicum.

Publications

Identifying the Growth Modulon of <i>Corynebacterium glutamicum</i>.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets