Article
Biotechnology & Applied Microbiology
Jannick Kappelmann, Bianca Klein, Mathias Papenfuss, Julian Lange, Bastian Blombach, Ralf Takors, Wolfgang Wiechert, Tino Polen, Stephan Noack
Summary: The study revealed the importance of PCx and PEPCk activity for balanced carbon and energy flux in the wild-type C. glutamicum. Unexpected genotype-phenotype relationships were unraveled in the mutants through comprehensive analysis. Interesting findings included the evolution of a mutant to grow on d-glucose as the sole carbon and energy source, and compensation of prevented anaplerotic carboxylation activity by up-regulation of the glyoxylate shunt in the evolved strain.
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
(2021)
Article
Biotechnology & Applied Microbiology
Naoya Kataoka, Minenosuke Matsutani, Kazunobu Matsushita, Toshiharu Yakushi
Summary: Corynebacterium glutamicum was engineered to produce phenylalanine, an important aromatic amino acid for the food and pharmaceutical industries. The production was achieved by overexpressing specific enzymes, inactivating certain pathways, and redirecting carbon flow. Mutations in the RNase J enzyme and modifications in phosphoenolpyruvate-pyruvate metabolism were found to significantly enhance phenylalanine production. The study provides insights into the practical mutations in constructing phenylalanine-producing C. glutamicum and the creation of potential strains for the biosynthesis of phenylalanine-derived compounds.
JOURNAL OF GENERAL AND APPLIED MICROBIOLOGY
(2023)
Article
Plant Sciences
Sander W. Hogewoning, Stefan A. J. van den Boogaart, Evelien van Tongerlo, Govert Trouwborst
Summary: This study elucidated the regulation of photosynthesis and carbon gain in the CAM plant Phalaenopsis cv. Sacramento, showing that factors such as light intensity, CO2 concentration, and diel variations play important roles. The findings revealed that malate storage capacity and the availability of PEP as substrate are not limiting factors for enhancing carbon gain in these CAM plants.
PLANT CELL AND ENVIRONMENT
(2021)
Article
Plant Sciences
Yangyang Wei, Zhaoguo Li, Tom C. Wedegaertner, Susan Jaconis, Sumei Wan, Zilin Zhao, Zhen Liu, Yuling Liu, Juyun Zheng, Kater D. Hake, Renhai Peng, Baohong Zhang
Summary: This study identified and analyzed the PEPC genes in cotton, revealing their presence and differentiation in different sub-genomes. The expression patterns of these genes were also examined during development and under stress conditions, uncovering their importance and functional diversity in cotton evolution.
Article
Plant Sciences
Qingchen Zhang, Yan Li, Weigang Xu, Yu Zhang, Xueli Qi, Yuhui Fang, Chaojun Peng
Summary: This study found that various combinations of maize genes had significant effects on the photosynthesis of Arabidopsis, with PCKM showing the best performance in improving photosynthetic rate and plant dry weight.
PLANT PHYSIOLOGY AND BIOCHEMISTRY
(2021)
Article
Biotechnology & Applied Microbiology
Felix Thoma, Clarissa Schulze, Carolina Gutierrez-Coto, Maurice Haedrich, Janine Huber, Christoph Gunkel, Rebecca Thoma, Bastian Blombach
Summary: This study presents an engineering approach for anaerobic succinate production with Vibrio natriegens, achieving high yield and productivity, with the final producer strain exhibiting encouraging performance indicators comparable to costly microbial production systems.
MICROBIAL BIOTECHNOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Ayano Komine-Abe, Naoko Kondo, Shosei Kubo, Hisashi Kawasaki, Makoto Nishiyama, Saori Kosono
Summary: In Corynebacterium glutamicum, acetylation of the lysine residue at position 391 on CgE2 was found to play a critical role in the assembly of PDH and ODH complexes, affecting their activities. Substitution of Lys391 with arginine in the CgE2-K391R variant strain led to increased l-glutamate production and reduced pyruvate accumulation, suggesting potential advantages for enhancing production efficiency.
BIOSCIENCE BIOTECHNOLOGY AND BIOCHEMISTRY
(2021)
Article
Biotechnology & Applied Microbiology
Jingbai Wen, Jie Bao
Summary: By secreting glutamate decarboxylase, Corynebacterium glutamicum achieved efficient production of γ-aminobutyric acid, significantly increasing the yield.
JOURNAL OF BIOTECHNOLOGY
(2021)
Article
Biotechnology & Applied Microbiology
Naoya Kataoka, Kazunobu Matsushita, Toshiharu Yakushi
Summary: In this study, a system for efficient production of 2-HG was developed using Corynebacterium glutamicum. The hgdH gene from Acidaminococcus fermentans was introduced into C. glutamicum, resulting in the biosynthesis of 2-OG. The engineered strain produced the highest reported titer and yield of 2-HG thus far under biotin- and nitrogen-limited conditions.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2023)
Article
Neurosciences
Caroline M. Voss, Lene Arildsen, Jakob D. Nissen, Helle S. Waagepetersen, Arne Schousboe, Pierre Maechler, Peter Ott, Hendrik Vilstrup, Anne B. Walls
Summary: This study highlights the central importance of GDH function in cerebral ammonia fixation and in the de novo synthesis of glutamate and glutamine during hyperammonemia. Additionally, the concerted action of GDH and alanine aminotransferase plays a crucial role in serving as an ammonia sink and substrate for ammonia fixation, highlighting a potential mechanism in human hyperammonemic states that warrants further investigation.
FRONTIERS IN NEUROSCIENCE
(2021)
Article
Plant Sciences
Jesus Perez-Lopez, Jacinto Gandullo, Clara de la Osa, Ana B. Feria, Cristina Echevarria, Jose A. Monreal, Sofia Garcia-Maurino
Summary: PPC3, a main root PEPC, plays a crucial role in responding to salinity and ammonium stress. However, Ppc3 lines showed greater susceptibility to aluminum and cadmium stress, leading to decreased growth rate and biomass production. Analysis of root exudates revealed that PPC3 is essential for the synthesis and accumulation of citrate, a key component in plant tolerance to heavy metal stress.
ENVIRONMENTAL AND EXPERIMENTAL BOTANY
(2023)
Article
Biotechnology & Applied Microbiology
Di Zhu, Caiyun Wu, Chenxin Niu, Hong Li, Fanglan Ge, Wei Li
Summary: In this study, the porphobilinogen synthase gene of C. glutamicum was cloned and expressed in E. coli. The enzymatic characteristics of C. glutamicum PBGS were analyzed, and it was found that the enzyme is Zn2+-dependent with allosteric regulation by Mg2+. Mutations in the active site and structural changes affect the enzyme's activity and quaternary structure equilibrium.
WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
(2023)
Article
Microbiology
Hedan Li, Daqing Xu, Xin Tan, Danyang Huang, Yu Huang, Guihong Zhao, Xiaoqing Hu, Xiaoyuan Wang
Summary: In this study, a mutant strain ASYA of Corynebacterium glutamicum was constructed to be unable to synthesize trehalose. ASYA grew as well as the control strain ATCC13869 in fermentation medium, but produced significantly more L-glutamate. In minimal medium, ASYA grew worse but excreted more L-glutamate. The major lipid in ASYA was phospholipids, while in ATCC13869 it was glucose monocorynomycolate, trehalose dicorynomycolate, and phospholipids.
MICROBIOLOGICAL RESEARCH
(2023)
Article
Plant Sciences
Jesus Perez-Lopez, Ana B. Feria, Jacinto Gandullo, Clara de la Osa, Irene Jimenez-Guerrero, Cristina Echevarria, Jose A. Monreal, Sofia Garcia-Maurino
Summary: Phosphoenolpyruvate carboxylase (PEPC) has crucial functions in various processes including photosynthesis, respiration, amino acid synthesis, and seed development. Its phosphorylation by PEPC-kinase (PEPCk) is well-documented. In this study, the silencing of three sorghum genes encoding PEPCk led to decreased phosphorylation of PEPC, altered metabolic profiles and amino acid content in leaves and seeds, delayed flowering, and reduced seed quantity and quality. These findings highlight the importance of PEPC phosphorylation in sorghum development, stress responses, yield, and seed quality.
Review
Psychiatry
Jun Shen, Jyoti Singh Tomar
Summary: Elevated brain glutamate levels in bipolar disorder may be explained by increased pyruvate carboxylase-mediated anaplerosis. Supporting evidence suggests that this mechanism is common in glutamatergic hyperactivity in bipolar disorder, as well as a positive association between bipolar disorder and obesity.
FRONTIERS IN PSYCHIATRY
(2021)