(Homo)acetogens, including Clostridium spp., represent an enigma in metabolic flexibility and diversity. Eubacterium callanderi KIST612 is an acetogen that produces n-butyrate with carbon monoxide (CO) as the carbon and energy source; however, the production route is unknown. Here, we report that its distinctive butyrate formation links to reductive acetate uptake, suggesting that acetate (the end-product) is reuptake, leading to a physiological advantage through NADH oxidation. Thus, we introduced an ethanol production pathway from acetyl-CoA as a competitive pathway for butyrate production. Consequently, the metabolic pathway in our mutants switched from acetogenesis to 'ethanologenesis', eliminating butyrate production and the uptake of previously produced acetate. The metabolic shifts occurred toward greater NADH oxidation, facilitating CO oxidation and productivity, which is a survival mechanism at the thermodynamic edge. This metabolic shift to a single product holds potential to revolutionize product separation strategies in synthetic gas (syngas)-based biorefineries.
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http://dx.doi.org/10.1016/j.tibtech.2024.11.008 | DOI Listing |
Nutrients
December 2024
Department of Physiology and Immunology, Faculty of Medicine Osijek, Josip Juraj Strossmayer University of Osijek, J. Huttlera 4, 31000 Osijek, Croatia.
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View Article and Find Full Text PDFMolecules
December 2024
Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata 990-9585, Japan.
Leucine, isoleucine, and valine are collectively known as branched chain amino acids (BCAAs) and are often discussed in the same physiological and pathological situations. The two consecutive initial reactions of BCAA catabolism are catalyzed by the common enzymes referred to as branched chain aminotransferase (BCAT) and branched chain α-keto acid dehydrogenase (BCKDH). BCAT transfers the amino group of BCAAs to 2-ketoglutarate, which results in corresponding branched chain 2-keto acids (BCKAs) and glutamate.
View Article and Find Full Text PDFAnimals (Basel)
December 2024
College of Advanced Agricultural Sciences, Zhejiang Wanli University, Ningbo 315101, China.
The razor clam , a significant marine bivalve species, inhabits estuaries and encounters salinity stress. Despite its commercial importance, there is limited understanding of its adaptive mechanisms to high salinity. Aldehyde dehydrogenases (ALDHs), which belong to the NAD(P)-dependent superfamily, play a crucial role in stress resilience by participating in catabolic and anabolic pathways, such as carnitine synthesis, glycolysis, and amino acid metabolism.
View Article and Find Full Text PDFCell Death Discov
January 2025
Institute of Preventive Medicine, School of Public Health, Dali University, No. 22, Wanhua Road, Dali, Yunnan, 671000, PR China.
Cadmium has been identified as an environmental pollutant and a carcinogen. N-methyladenosine (mA) plays a crucial role in the development of lung tumors, but the mechanisms remain incompletely clarified. In present study, our data demonstrated that prolonged treatment of 1 μmol/L CdSO for 40 passages in bronchial epithelial cells (Beas-2B cells) resulted in the development of a malignant phenotype, which manifested as boosted proliferation, migration and invasion capacity as well as apoptosis reduction.
View Article and Find Full Text PDFTrends Biotechnol
January 2025
School of Environment and Energy Engineering, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea; Research Center for Innovative Energy and Carbon Optimized Synthesis for Chemicals, Gwangju Institute of Science and Technology, 123 Cheomdan-gwagiro, Buk-gu, Gwangju 61005, Republic of Korea. Electronic address:
(Homo)acetogens, including Clostridium spp., represent an enigma in metabolic flexibility and diversity. Eubacterium callanderi KIST612 is an acetogen that produces n-butyrate with carbon monoxide (CO) as the carbon and energy source; however, the production route is unknown.
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