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Tian S, Zhao G, Lv G, Wu C, Su R, Wang F, Wang Z, Liu Y, Chen N, Li Y. Efficient Fermentative Production of d-Alanine and Other d-Amino Acids by Metabolically Engineered Corynebacterium glutamicum. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:8039-8051. [PMID: 38545740 DOI: 10.1021/acs.jafc.4c00914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
d-Amino acids (d-AAs) have wide applications in industries such as pharmaceutical, food, and cosmetics due to their unique properties. Currently, the production of d-AAs has relied on chemical synthesis or enzyme catalysts, and it is challenging to produce d-AAs via direct fermentation from glucose. We observed that Corynebacterium glutamicum exhibits a remarkable tolerance to high concentrations of d-Ala, a crucial characteristic for establishing a successful fermentation process. By optimizing meso-diaminopilmelate dehydrogenases in different C. glutamicum strains and successively deleting l-Ala biosynthetic pathways, we developed an efficient d-Ala fermentation system. The d-Ala titer was enhanced through systems metabolic engineering, which involved strengthening glucose assimilation and pyruvate supply, reducing the formation of organic acid byproducts, and attenuating the TCA cycle. During fermentation in a 5-L bioreactor, a significant accumulation of l-Ala was observed in the broth, which was subsequently diminished by introducing an l-amino acid deaminase. Ultimately, the engineered strain DA-11 produced 85 g/L d-Ala with a yield of 0.30 g/g glucose, accompanied by an optical purity exceeding 99%. The fermentation platform has the potential to be extended for the synthesis of other d-AAs, as demonstrated by the production of d-Val and d-Glu.
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Affiliation(s)
- Siyu Tian
- College of Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
| | - Guihong Zhao
- College of Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
| | - Gengcheng Lv
- College of Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
| | - Chen Wu
- College of Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
| | - Rui Su
- College of Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
| | - Feiao Wang
- College of Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
| | - Zeting Wang
- College of Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
| | - Yuexiang Liu
- College of Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
| | - Ning Chen
- College of Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
| | - Yanjun Li
- College of Biotechnology, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin University of Science and Technology, No. 29, 13th Avenue, TEDA, Tianjin 300457, China
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Heuser E, Becker K, Idelevich EA. Bactericidal Activity of Sodium Bituminosulfonate against Staphylococcus aureus. Antibiotics (Basel) 2022; 11:antibiotics11070896. [PMID: 35884150 PMCID: PMC9311858 DOI: 10.3390/antibiotics11070896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 12/10/2022] Open
Abstract
Antibiotic resistance is increasing worldwide making it necessary to search for alternative antimicrobials. Sodium bituminosulfonate is a long-known substance, whose antimicrobial inhibitory activity has recently been re-evaluated. However, to the best of our knowledge, the bactericidal mode of action of this substance has not been systematically characterized. The aim of this study was to investigate the in vitro bactericidal activity of sodium bituminosulfonate by determining the minimal bactericidal concentrations (MBC), as well as the rapidity of bactericidal effect by time-kill curves. Clinical isolates of methicillin-susceptible (MSSA, n = 20) and methicillin-resistant (mecA/mecC-MRSA, n = 20) Staphylococcus aureus were used to determine MBC by a broth microdilution method. Sodium bituminosulfonate (Ichthyol® light) was tested in double-dilution concentration steps ranging from 0.03 g/L to 256 g/L. For time-kill analysis, two reference and two clinical S. aureus strains were tested with different concentrations of sodium bituminosulfonate (1× minimal inhibitory concentration (MIC), 2× MIC, 4× MIC, 16× MIC and 256× MIC). For MSSA isolates, MBC50, MBC90 and the MBC range were 0.5 g/L, 1.0 g/L and 0.125–1.0 g/L; (MBC/MIC ratio)50, (MBC/MIC ratio)90 and the range of the MBC/MIC ratio were 4, 4 and 1–8, respectively. Among MRSA isolates, MBC50, MBC90 and the MBC range amounted to 0.5 g/L, 1.0 g/L and 0.06–1.0 g/L; (MBC/MIC ratio)50, (MBC/MIC ratio)90 and the range of the MBC/MIC ratio were 2, 4 and 1–8, respectively. Time-kill kinetics revealed a bactericidal effect after 30 min for sodium bituminosulfonate concentrations of 16× MIC and 256× MIC. The bactericidal activity against MSSA and MRSA was demonstrated for sodium bituminosulfonate. The killing was very rapid with the initial population reduced by 99.9% after only short incubation with concentrations of 16× MIC and higher.
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Affiliation(s)
- Elisa Heuser
- Friedrich Loeffler-Institute of Medical Microbiology, University Medicine Greifswald, Ferdinand-Sauerbruch-Straße 1, 17489 Greifswald, Germany; (E.H.); (K.B.)
| | - Karsten Becker
- Friedrich Loeffler-Institute of Medical Microbiology, University Medicine Greifswald, Ferdinand-Sauerbruch-Straße 1, 17489 Greifswald, Germany; (E.H.); (K.B.)
| | - Evgeny A. Idelevich
- Friedrich Loeffler-Institute of Medical Microbiology, University Medicine Greifswald, Ferdinand-Sauerbruch-Straße 1, 17489 Greifswald, Germany; (E.H.); (K.B.)
- Institute of Medical Microbiology, University Hospital Münster, Domagkstraße 10, 48149 Münster, Germany
- Correspondence: ; Tel.: +49-3834-86-5563; Fax: +49-3834-86-5561
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