scholarly journals Altered Metabolic Flux due to Deletion of odhA causes l-Glutamate Overproduction in Corynebacterium glutamicum

2006 ◽  
Vol 73 (4) ◽  
pp. 1308-1319 ◽  
Author(s):  
Yoko Asakura ◽  
Eiichiro Kimura ◽  
Yoshihiro Usuda ◽  
Yoshio Kawahara ◽  
Kazuhiko Matsui ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Corynebacterium Glutamicum ◽  
Metabolic Flux ◽  
Dry Weight ◽  
Wild Type ◽  
Glutamate Production ◽  
Glutamate Dehydrogenase Activity ◽  
Tween 40 ◽  
Oxoglutarate Dehydrogenase ◽  
The Relationship

ABSTRACT l-Glutamate overproduction in Corynebacterium glutamicum, a biotin auxotroph, is induced by biotin limitation or by treatment with certain fatty acid ester surfactants or with penicillin. We have analyzed the relationship between the inductions, 2-oxoglutarate dehydrogenase complex (ODHC) activity, and l-glutamate production. Here we show that a strain deleted for odhA and completely lacking ODHC activity produces l-glutamate as efficiently as the induced wild type (27.8 mmol/g [dry weight] of cells for the ohdA deletion strain compared with only 1.0 mmol/g [dry weight] of cells for the uninduced wild type). This level of production is achieved without any induction or alteration in the fatty acid composition of the cells, showing that l-glutamate overproduction can be caused by the change in metabolic flux alone. Interestingly, the l-glutamate productivity of the odhA-deleted strain is increased about 10% by each of the l-glutamate-producing inductions, showing that the change in metabolic flux resulting from the odhA deletion and the inductions have additive effects on l-glutamate overproduction. Tween 40 was indicated to induce drastic metabolic change leading to l-glutamate overproduction in the odhA-deleted strain. Furthermore, optimizing the metabolic flux from 2-oxoglutarate to l-glutamate by tuning glutamate dehydrogenase activity increased the l-glutamate production of the odhA-deleted strain.

scholarly journals Cometabolism of a Nongrowth Substrate: l-Serine Utilization by Corynebacterium glutamicum

2004 ◽  
Vol 70 (12) ◽  
pp. 7148-7155 ◽  
Author(s):  
Roman Netzer ◽  
Petra Peters-Wendisch ◽  
Lothar Eggeling ◽  
Hermann Sahm
Keyword(s):  
Growth Rate ◽  
Corynebacterium Glutamicum ◽  
Recombinant Strain ◽  
Growth Yield ◽  
Dry Weight ◽  
Resonance Spectroscopy ◽  
Central Metabolism ◽  
Wild Type ◽  
Single Substrate ◽  
Serine Dehydratase

ABSTRACT Despite its key position in central metabolism, l-serine does not support the growth of Corynebacterium glutamicum. Nevertheless, during growth on glucose, l-serine is consumed at rates up to 19.4 ± 4.0 nmol min−1 (mg [dry weight])−1, resulting in the complete consumption of 100 mM l-serine in the presence of 100 mM glucose and an increased growth yield of about 20%. Use of 13C-labeled l-serine and analysis of cellularly derived metabolites by nuclear magnetic resonance spectroscopy revealed that the carbon skeleton of l-serine is mainly converted to pyruvate-derived metabolites such as l-alanine. The sdaA gene was identified in the genome of C. glutamicum, and overexpression of sdaA resulted in (i) functional l-serine dehydratase (l-SerDH) activity, and therefore conversion of l-serine to pyruvate, and (ii) growth of the recombinant strain on l-serine as the single substrate. In contrast, deletion of sdaA decreased the l-serine cometabolism rate with glucose by 47% but still resulted in degradation of l-serine to pyruvate. Cystathionine β-lyase was additionally found to convert l-serine to pyruvate, and the respective metC gene was induced 2.4-fold under high internal l-serine concentrations. Upon sdaA overexpression, the growth rate on glucose is reduced 36% from that of the wild type, illustrating that even with glucose as a single substrate, intracellular l-serine conversion to pyruvate might occur, although probably the weak affinity of l-SerDH (apparent Km , 11 mM) prevents substantial l-serine degradation.

Characterization of lysine acetylation in the peripheral subunit-binding domain of the E2 subunit of the pyruvate dehydrogenase-2-oxoglutarate dehydrogenase hybrid complex from Corynebacterium glutamicum

2020 ◽  
Vol 85 (4) ◽  
pp. 874-881
Author(s):  
Ayano Komine-Abe ◽  
Naoko Kondo ◽  
Shosei Kubo ◽  
Hisashi Kawasaki ◽  
Makoto Nishiyama ◽  
...  
Keyword(s):  
Corynebacterium Glutamicum ◽  
Pyruvate Dehydrogenase ◽  
Critical Role ◽  
Binding Domain ◽  
Lysine Acetylation ◽  
Hybrid Complex ◽  
Glutamate Production ◽  
Accumulation Kinetic ◽  
Oxoglutarate Dehydrogenase

ABSTRACT In Corynebacterium glutamicum, pyruvate dehydrogenase (PDH) and 2-oxoglutarate dehydrogenase (ODH) form a unique hybrid complex in which CgE1p and CgE1o are associated with the CgE2–CgE3 subcomplex. We analyzed the role of a lysine acetylation site in the peripheral subunit-binding domain of CgE2 in PDH and ODH functions. Acetylation-mimic substitution at Lys391 of CgE2 severely reduced the interaction of CgE2 with CgE1p and CgE3, but not with CgE1o, indicating the critical role of this residue in the assembly of CgE1p and CgE3 into the complex. It also suggested that Lys391 acetylation inhibited the binding of CgE1p and CgE3 to CgE2, thereby affecting PDH and ODH activities. Interestingly, the CgE2-K391R variant strain showed increased l-glutamate production and reduced pyruvate accumulation. Kinetic analysis suggested that the increased affinity of the K391R variant toward pyruvate might be advantageous for l-glutamate production.

Effect of odhA overexpression and odhA antisense RNA expression on Tween-40-triggered glutamate production by Corynebacterium glutamicum

2009 ◽  
Vol 81 (6) ◽  
pp. 1097-1106 ◽  
Author(s):  
Jongpill Kim ◽  
Takashi Hirasawa ◽  
Yoshiyasu Sato ◽  
Keisuke Nagahisa ◽  
Chikara Furusawa ◽  
...  
Keyword(s):  
Corynebacterium Glutamicum ◽  
Antisense Rna ◽  
Rna Expression ◽  
Glutamate Production ◽  
Tween 40

Biomass production, transpiration rate and endogenous abscisic acid levels in grafts of flacca and wild-type tomato (Lycopersicon esculentum)

2002 ◽  
Vol 29 (11) ◽  
pp. 1329 ◽  
Author(s):  
Guoxiong Chen ◽  
S. Herman Lips ◽  
Moshe Sagi
Keyword(s):  
Plant Growth ◽  
Biomass Production ◽  
Transpiration Rate ◽  
Loading Rate ◽  
Dry Weight ◽  
Wild Type ◽  
Signalling Molecule ◽  
Xylem Loading ◽  
The Relationship ◽  
Endogenous Aba

ABA is a plant signalling-molecule that plays a key role in regulating stomatal response, stress-tolerance responses, and coordinated growth of roots and shoots. Knowledge of the relationship between endogenous ABA level and plant growth is essential for improving plant growth and productivity. The wild-type tomato Rheinlands Ruhm (RR) and its flacca mutant were grafted in order to determine the relationship between endogenous ABA levels and biomass production. The flacca genotype is an ABA-deficient mutant, characterized by high stomatal conductance during the day or the night, high transpiration rate, marked tendency to wilt, and smaller size. Flacca scions grafted on to wild-type rootstock (Fs/Wr) exhibited higher ABA levels, lower transpiration rate, and higher water content than those of a control graft of flacca scion on flacca rootstock (Fs/Fr). Fs/Wr exhibited a lower ABA concentration, xylem exudate rate, ABA xylem-loading rate, and dry weight biomass in wild-type rootstock than in control grafts of wild-type scion on wild-type rootstock (Ws/Wr). Flacca rootstock grafted to wild-type scion (Ws/Fr) showed a higher ABA level, xylem exudation rate, ABA xylem-loading rate, dry weight biomass and length than grafts to flacca scion (Fs/Fr). Ws/Fr did not induce significant changes in wild-type scion as compared with Ws/Wr. In double grafts, flacca shoot fresh weight was significantly increased in flacca scion and wild-type scion grafted on to flacca rootstock (Fs + Ws/Fr) or wild-type rootstock (Fs + Ws/Wr). There was a significant linear relationship between biomass and ABA in scions (r=0.997, P=0.001). These results support the notion that ABA increases growth of tomato seedlings via improved stomatal control.

scholarly journals Engineering of a Glycerol Utilization Pathway for Amino Acid Production by Corynebacterium glutamicum

2008 ◽  
Vol 74 (20) ◽  
pp. 6216-6222 ◽  
Author(s):  
Doris Rittmann ◽  
Steffen N. Lindner ◽  
Volker F. Wendisch
Keyword(s):  
Amino Acid ◽  
Corynebacterium Glutamicum ◽  
Biodiesel Production ◽  
Carbon Substrate ◽  
Wild Type ◽  
E Coli ◽  
Glutamate Production ◽  
Glycerol Utilization ◽  
Glycerol 3 Phosphate Dehydrogenase ◽  
Utilization Pathway

ABSTRACT The amino acid-producing organism Corynebacterium glutamicum cannot utilize glycerol, a stoichiometric by-product of biodiesel production. By heterologous expression of Escherichia coli glycerol utilization genes, C. glutamicum was engineered to grow on glycerol. While expression of the E. coli genes for glycerol kinase (glpK) and glycerol 3-phosphate dehydrogenase (glpD) was sufficient for growth on glycerol as the sole carbon and energy source, additional expression of the aquaglyceroporin gene glpF from E. coli increased growth rate and biomass formation. Glutamate production from glycerol was enabled by plasmid-borne expression of E. coli glpF, glpK, and glpD in C. glutamicum wild type. In addition, a lysine-producing C. glutamicum strain expressing E. coli glpF, glpK, and glpD was able to produce lysine from glycerol as the sole carbon substrate as well as from glycerol-glucose mixtures.

Effects of an Autoregulatory Senescence-inhibitor Gene Construct on Nicotiana alata Link and Otto.

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 519d-519 ◽  
Author(s):  
Kenneth R. Schroeder ◽  
Dennis P. Stimart
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Plant Height ◽  
Dry Weight ◽  
Nicotiana Alata ◽  
Wild Type ◽  
Gene Encoding ◽  
Delayed Senescence ◽  
Gene Construct ◽  
Shoot Dry Weight ◽  
Inhibitor System

Nicotiana alata Link and Otto. was transformed via Agrobacterium tumefaciens encoding a senescence-specific promoter SAG12 cloned from Arabidopsis thaliana fused to a Agrobacterium tumefaciens gene encoding isopentenyl transferase (IPT) that catalyzes cytokinin synthesis. This was considered an autoregulatory senescence-inhibitor system. In 1996, we reported delayed senescence of intact flowers by 2 to 6 d and delayed leaf senescence of transgenic vs. wild-type N. alata. Further evaluations in 1997 revealed several other interesting effects of the SAG12-IPT gene construct. Measurement of chlorophyll content of mature leaves showed higher levels of both chlorophyll a and b in transgenic material under normal fertilization and truncated fertilization regimes. At 4 to 5 months of age transgenic plants expressed differences in plant height, branching, and dry weight. Plant height was reduced by 3 to 13 cm; branch counts increased 2 to 3 fold; and shoot dry weight increased up to 11 g over wild-type N. alata. These observations indicate the system is not tightly autoregulated and may prove useful to the floriculture industry for producing compact and more floriferous plants.

scholarly journals Overexpression of vesicle-associated membrane protein PttVAP27-17 as a tool to improve biomass production and the overall saccharification yields in Populus trees

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Madhavi Latha Gandla ◽  
Niklas Mähler ◽  
Sacha Escamez ◽  
Tomas Skotare ◽  
Ogonna Obudulu ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Biomass Production ◽  
Enzymatic Saccharification ◽  
Dry Weight ◽  
Populus Tremula ◽  
Transgenic Trees ◽  
Wild Type ◽  
Glucose Yield ◽  
Transgenic Lines ◽  
Wild Type Control

Abstract Background Bioconversion of wood into bioproducts and biofuels is hindered by the recalcitrance of woody raw material to bioprocesses such as enzymatic saccharification. Targeted modification of the chemical composition of the feedstock can improve saccharification but this gain is often abrogated by concomitant reduction in tree growth. Results In this study, we report on transgenic hybrid aspen (Populus tremula × tremuloides) lines that showed potential to increase biomass production both in the greenhouse and after 5 years of growth in the field. The transgenic lines carried an overexpression construct for Populus tremula × tremuloides vesicle-associated membrane protein (VAMP)-associated protein PttVAP27-17 that was selected from a gene-mining program for novel regulators of wood formation. Analytical-scale enzymatic saccharification without any pretreatment revealed for all greenhouse-grown transgenic lines, compared to the wild type, a 20–44% increase in the glucose yield per dry weight after enzymatic saccharification, even though it was statistically significant only for one line. The glucose yield after enzymatic saccharification with a prior hydrothermal pretreatment step with sulfuric acid was not increased in the greenhouse-grown transgenic trees on a dry-weight basis, but increased by 26–50% when calculated on a whole biomass basis in comparison to the wild-type control. Tendencies to increased glucose yields by up to 24% were present on a whole tree biomass basis after acidic pretreatment and enzymatic saccharification also in the transgenic trees grown for 5 years on the field when compared to the wild-type control. Conclusions The results demonstrate the usefulness of gene-mining programs to identify novel genes with the potential to improve biofuel production in tree biotechnology programs. Furthermore, multi-omic analyses, including transcriptomic, proteomic and metabolomic analyses, performed here provide a toolbox for future studies on the function of VAP27 proteins in plants.

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