Dataset Information

Physiological Response of Corynebacterium glutamicum to Increasingly Nutrient-Rich Growth Conditions.

ABSTRACT: To ensure economic competitiveness, bioprocesses should achieve maximum productivities enabled by high growth rates (?) and equally high substrate consumption rates (q_S) 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 (q_Glc) were solely observed in certain dosages of BHI (1-10 g L^-1), while 37 g BHI L^-1 and AA addition revealed q_Glc below the reference experiments. Moreover, BHI supplementation revealed Monod-type saturation kinetics of ? (K_BHI = 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 g_CDW 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.

SUBMITTER: Graf M

PROVIDER: S-EPMC6123352 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Physiological Response of Corynebacterium glutamicum to Increasingly Nutrient-Rich Growth Conditions.

Graf Michaela M Zieringer Julia J Haas Thorsten T Nieß Alexander A Blombach Bastian B Takors Ralf R

Frontiers in microbiology 20180829

To ensure economic competitiveness, bioprocesses should achieve maximum productivities enabled by high growth rates (μ) 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 ...[more]

PMID: 30210489

Similar Datasets

Project description:The bacterium Corynebacterium glutamicum is utilized during industrial fermentation to produce amino acids such as L-glutamate. During L-glutamate fermentation, C. glutamicum changes the flux of central carbon metabolism to favor L-glutamate production, but the molecular mechanisms that explain these flux changes remain largely unknown. Here, we found that the profiles of two major lysine acyl modifications were significantly altered upon glutamate overproduction in C. glutamicum; acetylation decreased, whereas succinylation increased. A label-free semi-quantitative proteomic analysis identified 604 acetylated proteins with 1328 unique acetylation sites and 288 succinylated proteins with 651 unique succinylation sites. Acetylation and succinylation targeted enzymes in central carbon metabolic pathways that are directly related to glutamate production, including the 2-oxoglutarate dehydrogenase complex (ODHC), a key enzyme regulating glutamate overproduction. Structural mapping revealed that several critical lysine residues in the ODHC components were susceptible to acetylation and succinylation. Furthermore, induction of glutamate production was associated with changes in the extent of acetylation and succinylation of lysine, suggesting that these modifications may affect the activity of enzymes involved in glutamate production. Deletion of phosphotransacetylase decreased the extent of protein acetylation in nonproducing condition, suggesting that acetyl phosphate-dependent acetylation is active in C. glutamicum. However, no effect was observed on the profiles of acetylation and succinylation in glutamate-producing condition upon disruption of acetyl phosphate metabolism or deacetylase homologs. It was considered likely that the reduced acetylation in glutamate-producing condition may reflect metabolic states where the flux through acid-producing pathways is very low, and substrates for acetylation do not accumulate in the cell. Succinylation would occur more easily than acetylation in such conditions where the substrates for both acetylation and succinylation are limited. This is the first study investigating the acetylome and succinylome of C. glutamicum, and it provides new insight into the roles of acyl modifications in C. glutamicum biology.

Dataset Information

Physiological Response of Corynebacterium glutamicum to Increasingly Nutrient-Rich Growth Conditions.

Publications

Physiological Response of <i>Corynebacterium glutamicum</i> to Increasingly Nutrient-Rich Growth Conditions.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets