1
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Niu H, Gu J, Zhang Y. Bacterial persisters: molecular mechanisms and therapeutic development. Signal Transduct Target Ther 2024; 9:174. [PMID: 39013893 PMCID: PMC11252167 DOI: 10.1038/s41392-024-01866-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Revised: 05/06/2024] [Accepted: 05/13/2024] [Indexed: 07/18/2024] Open
Abstract
Persisters refer to genetically drug susceptible quiescent (non-growing or slow growing) bacteria that survive in stress environments such as antibiotic exposure, acidic and starvation conditions. These cells can regrow after stress removal and remain susceptible to the same stress. Persisters are underlying the problems of treating chronic and persistent infections and relapse infections after treatment, drug resistance development, and biofilm infections, and pose significant challenges for effective treatments. Understanding the characteristics and the exact mechanisms of persister formation, especially the key molecules that affect the formation and survival of the persisters is critical to more effective treatment of chronic and persistent infections. Currently, genes related to persister formation and survival are being discovered and confirmed, but the mechanisms by which bacteria form persisters are very complex, and there are still many unanswered questions. This article comprehensively summarizes the historical background of bacterial persisters, details their complex characteristics and their relationship with antibiotic tolerant and resistant bacteria, systematically elucidates the interplay between various bacterial biological processes and the formation of persister cells, as well as consolidates the diverse anti-persister compounds and treatments. We hope to provide theoretical background for in-depth research on mechanisms of persisters and suggest new ideas for choosing strategies for more effective treatment of persistent infections.
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Affiliation(s)
- Hongxia Niu
- School of Basic Medical Science and Key Laboratory of Blood-stasis-toxin Syndrome of Zhejiang Province, Zhejiang Chinese Medical University, Hangzhou, 310053, Zhejiang, China
| | - Jiaying Gu
- School of Basic Medical Science and Key Laboratory of Blood-stasis-toxin Syndrome of Zhejiang Province, Zhejiang Chinese Medical University, Hangzhou, 310053, Zhejiang, China
| | - Ying Zhang
- State Key Laboratory for the Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, 310003, Zhejiang, China.
- Jinan Microecological Biomedicine Shandong Laboratory, Jinan, 250022, Shandong, China.
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2
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Réthi-Nagy Z, Juhász S. Microbiome's Universe: Impact on health, disease and cancer treatment. J Biotechnol 2024; 392:161-179. [PMID: 39009231 DOI: 10.1016/j.jbiotec.2024.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/27/2024] [Accepted: 07/07/2024] [Indexed: 07/17/2024]
Abstract
The human microbiome is a diverse ecosystem of microorganisms that reside in the body and influence various aspects of health and well-being. Recent advances in sequencing technology have brought to light microbial communities in organs and tissues that were previously considered sterile. The gut microbiota plays an important role in host physiology, including metabolic functions and immune modulation. Disruptions in the balance of the microbiome, known as dysbiosis, have been linked to diseases such as cancer, inflammatory bowel disease and metabolic disorders. In addition, the administration of antibiotics can lead to dysbiosis by disrupting the structure and function of the gut microbial community. Targeting strategies are the key to rebalancing the microbiome and fighting disease, including cancer, through interventions such as probiotics, fecal microbiota transplantation (FMT), and bacteria-based therapies. Future research must focus on understanding the complex interactions between diet, the microbiome and cancer in order to optimize personalized interventions. Multidisciplinary collaborations are essential if we are going to translate microbiome research into clinical practice. This will revolutionize approaches to cancer prevention and treatment.
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Affiliation(s)
- Zsuzsánna Réthi-Nagy
- Hungarian Centre of Excellence for Molecular Medicine, Cancer Microbiome Core Group, Budapesti út 9, Szeged H-6728, Hungary
| | - Szilvia Juhász
- Hungarian Centre of Excellence for Molecular Medicine, Cancer Microbiome Core Group, Budapesti út 9, Szeged H-6728, Hungary.
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3
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Dadi P, Pauling CW, Shrivastava A, Shah DD. Synthesis of versatile neuromodulatory molecules by a gut microbial glutamate decarboxylase. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.02.583032. [PMID: 38915512 PMCID: PMC11195143 DOI: 10.1101/2024.03.02.583032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Dysbiosis of the microbiome correlates with many neurological disorders, yet very little is known about the chemistry that controls the production of neuromodulatory molecules by gut microbes. Here, we found that an enzyme glutamate decarboxylase (BfGAD) of a gut microbe Bacteroides fragilis forms multiple neuromodulatory molecules such as γ-aminobutyric acid (GABA), hypotaurine, taurine, homotaurine, and β-alanine. We evolved BfGAD and doubled its taurine productivity. Additionally, we increased its specificity towards the substrate L-glutamate. Here, we provide a chemical strategy via which the BfGAD activity could be fine-tuned. In future, this strategy could be used to modulate the production of neuromodulatory molecules by gut microbes.
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Affiliation(s)
- Pavani Dadi
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ 85281
- School of Life Sciences, Arizona State University, Tempe, AZ 85281
| | - Clint W. Pauling
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ 85281
- School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ 85306
| | - Abhishek Shrivastava
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ 85281
- School of Life Sciences, Arizona State University, Tempe, AZ 85281
| | - Dhara D. Shah
- Biodesign Center for Fundamental and Applied Microbiomics, Arizona State University, Tempe, AZ 85281
- School of Mathematical and Natural Sciences, Arizona State University, Glendale, AZ 85306
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4
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Gorelik MG, Yakhnin H, Pannuri A, Walker AC, Pourciau C, Czyz D, Romeo T, Babitzke P. Multitier regulation of the E. coli extreme acid stress response by CsrA. J Bacteriol 2024; 206:e0035423. [PMID: 38319100 PMCID: PMC11210196 DOI: 10.1128/jb.00354-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 01/15/2024] [Indexed: 02/07/2024] Open
Abstract
CsrA is an RNA-binding protein that regulates processes critical for growth and survival, including central carbon metabolism, motility, biofilm formation, stress responses, and expression of virulence factors in pathogens. Transcriptomics studies in Escherichia coli suggested that CsrA repressed genes involved in surviving extremely acidic conditions. Here, we examine the effects of disrupting CsrA-dependent regulation on the expression of genes and circuitry for acid stress survival and demonstrate CsrA-mediated repression at multiple levels. We show that this repression is critical for managing the trade-off between growth and survival; overexpression of acid stress genes caused by csrA disruption enhances survival under extreme acidity but is detrimental for growth under mildly acidic conditions. In vitro studies confirmed that CsrA binds specifically to mRNAs of structural and regulatory genes for acid stress survival, causing translational repression. We also found that translation of the top-tier acid stress regulator, evgA, is coupled to that of a small leader peptide, evgL, which is repressed by CsrA. Unlike dedicated acid stress response genes, csrA and its sRNA antagonists, csrB and csrC, did not exhibit a substantial response to acid shock. Furthermore, disruption of CsrA regulation of acid stress genes impacted host-microbe interactions in Caenorhabditis elegans, alleviating GABA deficiencies. This study expands the known regulon of CsrA to genes of the extreme acid stress response of E. coli and highlights a new facet of the global role played by CsrA in balancing the opposing physiological demands of stress resistance with the capacity for growth and modulating host interactions.IMPORTANCETo colonize/infect the mammalian intestinal tract, bacteria must survive exposure to the extreme acidity of the stomach. E. coli does this by expressing proteins that neutralize cytoplasmic acidity and cope with molecular damage caused by low pH. Because of the metabolic cost of these processes, genes for surviving acid stress are tightly regulated. Here, we show that CsrA negatively regulates the cascade of expression responsible for the acid stress response. Increased expression of acid response genes due to csrA disruption improved survival at extremely low pH but inhibited growth under mildly acidic conditions. Our findings define a new layer of regulation in the acid stress response of E. coli and a novel physiological function for CsrA.
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Affiliation(s)
- Mark G. Gorelik
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Helen Yakhnin
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Archana Pannuri
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Alyssa C. Walker
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Christine Pourciau
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
| | - Daniel Czyz
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Tony Romeo
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, USA
| | - Paul Babitzke
- Department of Biochemistry and Molecular Biology, Center for RNA Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, USA
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5
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Zepeda-Rivera M, Minot SS, Bouzek H, Wu H, Blanco-Míguez A, Manghi P, Jones DS, LaCourse KD, Wu Y, McMahon EF, Park SN, Lim YK, Kempchinsky AG, Willis AD, Cotton SL, Yost SC, Sicinska E, Kook JK, Dewhirst FE, Segata N, Bullman S, Johnston CD. A distinct Fusobacterium nucleatum clade dominates the colorectal cancer niche. Nature 2024; 628:424-432. [PMID: 38509359 PMCID: PMC11006615 DOI: 10.1038/s41586-024-07182-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Accepted: 02/08/2024] [Indexed: 03/22/2024]
Abstract
Fusobacterium nucleatum (Fn), a bacterium present in the human oral cavity and rarely found in the lower gastrointestinal tract of healthy individuals1, is enriched in human colorectal cancer (CRC) tumours2-5. High intratumoural Fn loads are associated with recurrence, metastases and poorer patient prognosis5-8. Here, to delineate Fn genetic factors facilitating tumour colonization, we generated closed genomes for 135 Fn strains; 80 oral strains from individuals without cancer and 55 unique cancer strains cultured from tumours from 51 patients with CRC. Pangenomic analyses identified 483 CRC-enriched genetic factors. Tumour-isolated strains predominantly belong to Fn subspecies animalis (Fna). However, genomic analyses reveal that Fna, considered a single subspecies, is instead composed of two distinct clades (Fna C1 and Fna C2). Of these, only Fna C2 dominates the CRC tumour niche. Inter-Fna analyses identified 195 Fna C2-associated genetic factors consistent with increased metabolic potential and colonization of the gastrointestinal tract. In support of this, Fna C2-treated mice had an increased number of intestinal adenomas and altered metabolites. Microbiome analysis of human tumour tissue from 116 patients with CRC demonstrated Fna C2 enrichment. Comparison of 62 paired specimens showed that only Fna C2 is tumour enriched compared to normal adjacent tissue. This was further supported by metagenomic analysis of stool samples from 627 patients with CRC and 619 healthy individuals. Collectively, our results identify the Fna clade bifurcation, show that specifically Fna C2 drives the reported Fn enrichment in human CRC and reveal the genetic underpinnings of pathoadaptation of Fna C2 to the CRC niche.
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Affiliation(s)
- Martha Zepeda-Rivera
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Samuel S Minot
- Data Core, Shared Resources, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Heather Bouzek
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Hanrui Wu
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Aitor Blanco-Míguez
- Department of Computational, Cellular and Integrative Biology, University of Trento, Trento, Italy
| | - Paolo Manghi
- Department of Computational, Cellular and Integrative Biology, University of Trento, Trento, Italy
| | - Dakota S Jones
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | | | - Ying Wu
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Elsa F McMahon
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, USA
| | - Soon-Nang Park
- Korean Collection for Oral Microbiology and Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju, Republic of Korea
| | - Yun K Lim
- Korean Collection for Oral Microbiology and Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju, Republic of Korea
| | | | - Amy D Willis
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | | | | | - Ewa Sicinska
- Department of Pathology, Dana-Farber Cancer Institute, Boston, MA, USA
| | - Joong-Ki Kook
- Korean Collection for Oral Microbiology and Department of Oral Biochemistry, School of Dentistry, Chosun University, Gwangju, Republic of Korea
| | - Floyd E Dewhirst
- Forsyth Institute, Cambridge, MA, USA
- Department of Oral Medicine, Infection and Immunity, Harvard School of Dental Medicine, Boston, MA, USA
| | - Nicola Segata
- Department of Computational, Cellular and Integrative Biology, University of Trento, Trento, Italy
| | - Susan Bullman
- Human Biology Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.
| | - Christopher D Johnston
- Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Center, Seattle, WA, USA.
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6
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Atasoy M, Álvarez Ordóñez A, Cenian A, Djukić-Vuković A, Lund PA, Ozogul F, Trček J, Ziv C, De Biase D. Exploitation of microbial activities at low pH to enhance planetary health. FEMS Microbiol Rev 2024; 48:fuad062. [PMID: 37985709 PMCID: PMC10963064 DOI: 10.1093/femsre/fuad062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/31/2023] [Accepted: 11/17/2023] [Indexed: 11/22/2023] Open
Abstract
Awareness is growing that human health cannot be considered in isolation but is inextricably woven with the health of the environment in which we live. It is, however, under-recognized that the sustainability of human activities strongly relies on preserving the equilibrium of the microbial communities living in/on/around us. Microbial metabolic activities are instrumental for production, functionalization, processing, and preservation of food. For circular economy, microbial metabolism would be exploited to produce building blocks for the chemical industry, to achieve effective crop protection, agri-food waste revalorization, or biofuel production, as well as in bioremediation and bioaugmentation of contaminated areas. Low pH is undoubtedly a key physical-chemical parameter that needs to be considered for exploiting the powerful microbial metabolic arsenal. Deviation from optimal pH conditions has profound effects on shaping the microbial communities responsible for carrying out essential processes. Furthermore, novel strategies to combat contaminations and infections by pathogens rely on microbial-derived acidic molecules that suppress/inhibit their growth. Herein, we present the state-of-the-art of the knowledge on the impact of acidic pH in many applied areas and how this knowledge can guide us to use the immense arsenal of microbial metabolic activities for their more impactful exploitation in a Planetary Health perspective.
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Affiliation(s)
- Merve Atasoy
- UNLOCK, Wageningen University & Research and Technical University Delft, Droevendaalsesteeg 4, 6708 PB,Wageningen, the Netherlands
| | - Avelino Álvarez Ordóñez
- Department of Food Hygiene and Technology and Institute of Food Science and Technology, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Adam Cenian
- Institute of Fluid Flow Machinery, Polish Academy of Sciences, Department of Physical Aspects of Ecoenergy, 14 Fiszera St., 80-231 Gdańsk, Poland
| | - Aleksandra Djukić-Vuković
- Department of Biochemical Engineering and Biotechnology, Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11120 Belgrade, Serbia
| | - Peter A Lund
- Institute of Microbiology and Infection,School of Biosciences, University of Birmingham, Birmingham B15 2TT, United Kingdom
| | - Fatih Ozogul
- Department of Seafood Processing and Technology, Faculty of Fisheries, Cukurova University, Balcali, 01330, Adana, Turkey
- Biotechnology Research and Application Center, Cukurova University, Balcali, 01330 Adana, Turkey
| | - Janja Trček
- Department of Biology, Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška cesta 160, 2000 Maribor, Slovenia
| | - Carmit Ziv
- Department of Postharvest Science, Agricultural Research Organization – Volcani Center, 68 HaMaccabim Road , P.O.B 15159 Rishon LeZion 7505101, Israel
| | - Daniela De Biase
- Department of Medico-Surgical Sciences and Biotechnologies, Sapienza University of Rome, Corso della Repubblica 79, 04100 Latina, Italy
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7
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Schumacher K, Gelhausen R, Kion-Crosby W, Barquist L, Backofen R, Jung K. Ribosome profiling reveals the fine-tuned response of Escherichia coli to mild and severe acid stress. mSystems 2023; 8:e0103723. [PMID: 37909716 PMCID: PMC10746267 DOI: 10.1128/msystems.01037-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 09/28/2023] [Indexed: 11/03/2023] Open
Abstract
IMPORTANCE Bacteria react very differently to survive in acidic environments, such as the human gastrointestinal tract. Escherichia coli is one of the extremely acid-resistant bacteria and has a variety of acid-defense mechanisms. Here, we provide the first genome-wide overview of the adaptations of E. coli K-12 to mild and severe acid stress at both the transcriptional and translational levels. Using ribosome profiling and RNA sequencing, we uncover novel adaptations to different degrees of acidity, including previously hidden stress-induced small proteins and novel key transcription factors for acid defense, and report mRNAs with pH-dependent differential translation efficiency. In addition, we distinguish between acid-specific adaptations and general stress response mechanisms using denoising autoencoders. This workflow represents a powerful approach that takes advantage of next-generation sequencing techniques and machine learning to systematically analyze bacterial stress responses.
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Affiliation(s)
- Kilian Schumacher
- Faculty of Biology, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Rick Gelhausen
- Bioinformatics Group, Department of Computer Science, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
| | - Willow Kion-Crosby
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
- University of Würzburg, Faculty of Medicine, Würzburg, Germany
| | - Lars Barquist
- Helmholtz Institute for RNA-based Infection Research (HIRI)/Helmholtz Centre for Infection Research (HZI), Würzburg, Germany
- University of Würzburg, Faculty of Medicine, Würzburg, Germany
| | - Rolf Backofen
- Bioinformatics Group, Department of Computer Science, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Kirsten Jung
- Faculty of Biology, Microbiology, Ludwig-Maximilians-Universität München, Martinsried, Germany
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8
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Nolte S, Krüger K, Lenz C, Zentgraf K. Optimizing the Gut Microbiota for Individualized Performance Development in Elite Athletes. BIOLOGY 2023; 12:1491. [PMID: 38132317 PMCID: PMC10740793 DOI: 10.3390/biology12121491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/23/2023] [Accepted: 11/28/2023] [Indexed: 12/23/2023]
Abstract
The human gut microbiota can be compared to a fingerprint due to its uniqueness, hosting trillions of living organisms. Taking a sport-centric perspective, the gut microbiota might represent a physiological system that relates to health aspects as well as individualized performance in athletes. The athletes' physiology has adapted to their exceptional lifestyle over the years, including the diversity and taxonomy of the microbiota. The gut microbiota is influenced by several physiological parameters and requires a highly individual and complex approach to unravel the linkage between performance and the microbial community. This approach has been taken in this review, highlighting the functions that the microbial community performs in sports, naming gut-centered targets, and aiming for both a healthy and sustainable athlete and performance development. With this article, we try to consider whether initiating a microbiota analysis is practicable and could add value in elite sport, and what possibilities it holds when influenced through a variety of interventions. The aim is to support enabling a well-rounded and sustainable athlete and establish a new methodology in elite sport.
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Affiliation(s)
- Svenja Nolte
- Department of Exercise Physiology and Sports Therapy, Institute of Sports Science, University of Giessen, 35394 Giessen, Germany; (K.K.); (C.L.)
| | - Karsten Krüger
- Department of Exercise Physiology and Sports Therapy, Institute of Sports Science, University of Giessen, 35394 Giessen, Germany; (K.K.); (C.L.)
| | - Claudia Lenz
- Department of Exercise Physiology and Sports Therapy, Institute of Sports Science, University of Giessen, 35394 Giessen, Germany; (K.K.); (C.L.)
| | - Karen Zentgraf
- Department 5: Psychology & Sports Sciences, Institute for Sports Sciences, Goethe University Frankfurt, 60323 Frankfurt am Main, Germany;
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9
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Zamakhaev M, Bespyatykh J, Goncharenko A, Shumkov M. The Benefits of Toxicity: M. smegmatis VapBC TA Module Is Induced by Tetracycline Exposure and Promotes Survival. Microorganisms 2023; 11:2863. [PMID: 38138007 PMCID: PMC10745673 DOI: 10.3390/microorganisms11122863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Revised: 11/15/2023] [Accepted: 11/22/2023] [Indexed: 12/24/2023] Open
Abstract
Toxin-antitoxin (TA) systems are widely present in bacterial genomes. Mycolicibacterium smegmatis, a common model organism for studying Mycobacterium tuberculosis physiology, has eight TA loci, including mazEF and vapBC. This study aims to investigate the physiological significance of these TA systems. Proteomic profiling was conducted on a culture overexpressing the VapC toxin, and the involvement of VapC in M. smegmatis stress responses to heat shock and antibiotic treatment was examined. While deciphering the underlying mechanisms of the altered stress resistance, we assessed the antibiotic susceptibility of vapBC, mazEF, and double vapBC-mazEF deletion mutants. Additionally, the mRNA levels of vapC and mazF were measured following tetracycline supplementation. The results reveal changes in the abundance of metabolic enzymes and stress response proteins associated with VapC overexpression. This activation of the general stress response leads to reduced thermosensitivity in M. smegmatis, but does not affect susceptibility to ciprofloxacin and isoniazid. Under tetracycline treatment, both vapC and mazF expression levels are increased, and the fate of the cell depends on the interaction between the corresponding TA systems.
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Affiliation(s)
- Mikhail Zamakhaev
- Federal Research Center Fundamentals of Biotechnology of the Russian Academy of Sciences, 33, bld. 2 Leninsky Ave., 119071 Moscow, Russia; (A.G.); (M.S.)
| | - Julia Bespyatykh
- Federal Research and Clinical Center of Physical-Chemical Medicine of Federal Medical Biological Agency, 1A Malaya Pirogovskaya St., 119435 Moscow, Russia;
- Expertise Department in Anti-Doping and Drug Control, Mendeleev University of Chemical Technology of Russia, 9, Miusskaya Sq., 125047 Moscow, Russia
| | - Anna Goncharenko
- Federal Research Center Fundamentals of Biotechnology of the Russian Academy of Sciences, 33, bld. 2 Leninsky Ave., 119071 Moscow, Russia; (A.G.); (M.S.)
| | - Mikhail Shumkov
- Federal Research Center Fundamentals of Biotechnology of the Russian Academy of Sciences, 33, bld. 2 Leninsky Ave., 119071 Moscow, Russia; (A.G.); (M.S.)
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10
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Khezri MR, Esmaeili A, Ghasemnejad-Berenji M. Role of Bmal1 and Gut Microbiota in Alzheimer's Disease and Parkinson's Disease Pathophysiology: The Probable Effect of Melatonin on Their Association. ACS Chem Neurosci 2023; 14:3883-3893. [PMID: 37823531 DOI: 10.1021/acschemneuro.3c00418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023] Open
Abstract
In recent years, the role of new factors in the pathophysiology of neurodegenerative diseases has been investigated. Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common neurodegenerative diseases worldwide. Although pathological changes such as the accumulation of aggregated proteins in the brain and inflammatory responses are known as the main factors involved in the development of these diseases, new studies show the role of gut microbiota and circadian rhythm in the occurrence of these changes. However, the association between circadian rhythm and gut microbiota in AD and PD has not yet been investigated. Recent results propose that alterations in circadian rhythm regulators, mainly Bmal1, may regulate the abundance of gut microbiota. This correlation has been linked to the regulation of the expression of immune-related genes and Bmal-1 mediated oscillation of IgA and hydrogen peroxide production. These data seem to provide new insight into the molecular mechanism of melatonin inhibiting the progression of AD and PD. Therefore, this manuscript aims to review the role of the gut microbiota and circadian rhythm in health and AD and PD and also presents a hypothesis on the effect of melatonin on their communication.
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Affiliation(s)
- Mohammad Rafi Khezri
- Faculty of Pharmacy. Urmia University of Medical Sciences, Urmia 571478334, Iran
| | - Ayda Esmaeili
- Department of Clinical Pharmacy, School of Pharmacy, Urmia University of Medical Sciences, Urmia 5715799313, Iran
| | - Morteza Ghasemnejad-Berenji
- Department of Pharmacology and Toxicology, School of Pharmacy, Urmia University of Medical Sciences, Urmia 5715799313, Iran
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11
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Wang S, Chen X, Jin X, Gu F, Jiang W, Qi Q, Liang Q. Creating Polyploid Escherichia Coli and Its Application in Efficient L-Threonine Production. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2302417. [PMID: 37749873 PMCID: PMC10625114 DOI: 10.1002/advs.202302417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 07/31/2023] [Indexed: 09/27/2023]
Abstract
Prokaryotic genomes are generally organized in haploid. In synthetic biological research, efficient chassis cells must be constructed to produce bio-based products. Here, the essential division of the ftsZ gene to create functional polyploid E. coli is regulated. The artificial polyploid E. coli containing 2-4 chromosomes is confirmed through PCR amplification, terminator localization, and flow cytometry. The polyploid E. coli exhibits a larger cell size, and its low pH tolerance and acetate resistance are stronger than those of haploid E. coli. Transcriptome analysis shows that the genes of the cell's main functional pathways are significantly upregulated in the polyploid E. coli. These advantages of the polyploid E. coli results in the highest reported L-threonine yield (160.3 g L-1 ) in fed-batch fermentation to date. In summary, an easy and convenient method for constructing polyploid E. coli and demonstrated its application in L-threonine production is developed. This work provides a new approach for creating an excellent host strain for biochemical production and studying the evolution of prokaryotes and their chromosome functions.
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Affiliation(s)
- Sumeng Wang
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
| | - Xuanmu Chen
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
| | - Xin Jin
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
| | - Fei Gu
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
| | - Wei Jiang
- Research Center of Basic MedicineCentral Hospital Affiliated to Shandong First Medical UniversityJinan250013P. R. China
| | - Qingsheng Qi
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
| | - Quanfeng Liang
- State Key Laboratory of Microbial TechnologyShandong UniversityQingdao266237P. R. China
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12
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Tamés H, Sabater C, Margolles A, Ruiz L, Ruas-Madiedo P. Production of GABA in milk fermented by Bifidobacterium adolescentis strains selected on the bases of their technological and gastrointestinal performance. Food Res Int 2023; 171:113009. [PMID: 37330847 DOI: 10.1016/j.foodres.2023.113009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 05/15/2023] [Accepted: 05/17/2023] [Indexed: 06/19/2023]
Abstract
There is an increasing interest in producing foods enriched in gamma-aminobutyric acid (GABA), due to their purported health promoting attributes. GABA is the main inhibitor neurotransmitter of the central nervous system, and several microbial species are capable to produce it through decarboxylation of glutamate. Among them, several lactic acid bacteria species have been previously investigated as an appealing alternative to produce GABA enriched foods via microbial fermentation. In this work we report for the first time an investigation into the possibility of utilizing high GABA-producing Bifidobacterium adolescentis strains as a mean to produce fermented probiotic milks naturally enriched in GABA. To this end, in silico and in vitro analyses were conducted in a collection of GABA-producing B. adolescentis strains, with the main goal to scrutinize their metabolic and safety traits, including antibiotic resistance patterns, as well as their technological robustness and performance to survive a simulated gastrointestinal passage. One of the strains, IPLA60004, exhibited better survival to lyophilization and cold storage (for up to 4 weeks at 4 °C), as well as survival to gastrointestinal passage, as compared to the other strains under investigation. Besides, the elaboration of milk drinks fermented with this strain, yielded products with the highest GABA concentration and viable bifidobacterial cell counts, achieving conversion rates of the precursor, monosodium glutamate (GMS), up to 70 %. To our knowledge, this is the first report on the elaboration of GABA enriched milks through fermentation with B. adolescentis.
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Affiliation(s)
- Héctor Tamés
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias-Consejo Superior de Investigaciones Científicas (IPLA-CSIC), Paseo Río Linares s/n, 33300 Villaviciosa, Asturias, Spain; Functionality and Ecology of Beneficial Microbes (MicroHealth) Group, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Asturias, Spain
| | - Carlos Sabater
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias-Consejo Superior de Investigaciones Científicas (IPLA-CSIC), Paseo Río Linares s/n, 33300 Villaviciosa, Asturias, Spain; Functionality and Ecology of Beneficial Microbes (MicroHealth) Group, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Asturias, Spain
| | - Abelardo Margolles
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias-Consejo Superior de Investigaciones Científicas (IPLA-CSIC), Paseo Río Linares s/n, 33300 Villaviciosa, Asturias, Spain; Functionality and Ecology of Beneficial Microbes (MicroHealth) Group, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Asturias, Spain
| | - Lorena Ruiz
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias-Consejo Superior de Investigaciones Científicas (IPLA-CSIC), Paseo Río Linares s/n, 33300 Villaviciosa, Asturias, Spain; Functionality and Ecology of Beneficial Microbes (MicroHealth) Group, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Asturias, Spain.
| | - Patricia Ruas-Madiedo
- Department of Microbiology and Biochemistry of Dairy Products, Instituto de Productos Lácteos de Asturias-Consejo Superior de Investigaciones Científicas (IPLA-CSIC), Paseo Río Linares s/n, 33300 Villaviciosa, Asturias, Spain; Functionality and Ecology of Beneficial Microbes (MicroHealth) Group, Instituto de Investigación Sanitaria del Principado de Asturias (ISPA), Oviedo, Asturias, Spain.
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13
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García E. Two putative glutamate decarboxylases of Streptococcus pneumoniae as possible antigens for the production of anti-GAD65 antibodies leading to type 1 diabetes mellitus. Int Microbiol 2023; 26:675-690. [PMID: 37154976 PMCID: PMC10165594 DOI: 10.1007/s10123-023-00364-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 04/13/2023] [Accepted: 04/21/2023] [Indexed: 05/10/2023]
Abstract
Type 1 diabetes mellitus (T1DM) has been increasing in prevalence in the last decades and has become a global burden. Autoantibodies against human glutamate decarboxylase (GAD65) are among the first to be detected at the onset of T1DM. Diverse viruses have been proposed to be involved in the triggering of T1DM because of molecular mimicry, i.e., similarity between parts of some viral proteins and one or more epitopes of GAD65. However, the possibility that bacterial proteins might also be responsible for GAD65 mimicry has been seldom investigated. To date, many genomes of Streptococcus pneumoniae (the pneumococcus), a prominent human pathogen particularly prevalent among children and the elderly, have been sequenced. A dataset of more than 9000 pneumococcal genomes was mined and two different (albeit related) genes (gadA and gadB), presumably encoding two glutamate decarboxylases similar to GAD65, were found. The various gadASpn alleles were present only in serotype 3 pneumococci belonging to the global lineage GPSC83, although some homologs have also been discovered in two subspecies of Streptococcus constellatus (pharyngis and viborgensis), an isolate of the group B streptococci, and several strains of Lactobacillus delbrueckii. Besides, gadBSpn alleles are present in > 10% of the isolates in our dataset and represent 16 GPSCs with 123 sequence types and 20 different serotypes. Sequence analyses indicated that gadA- and gadB-like genes have been mobilized among different bacteria either by prophage(s) or by integrative and conjugative element(s), respectively. Substantial similarities appear to exist between the putative pneumococcal glutamate decarboxylases and well-known epitopes of GAD65. In this sense, the use of broader pneumococcal conjugate vaccines such as PCV20 would prevent the majority of serotypes expressing those genes that might potentially contribute to T1DM. These results deserve upcoming studies on the possible involvement of S. pneumoniae in the etiopathogenesis and clinical onset of T1DM.
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Affiliation(s)
- Ernesto García
- Departamento de Biotecnología Microbiana y de Plantas, Centro de Investigaciones Biológicas Margarita Salas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain.
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14
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Merchant JP, Zhu K, Henrion MYR, Zaidi SSA, Lau B, Moein S, Alamprese ML, Pearse RV, Bennett DA, Ertekin-Taner N, Young-Pearse TL, Chang R. Predictive network analysis identifies JMJD6 and other potential key drivers in Alzheimer's disease. Commun Biol 2023; 6:503. [PMID: 37188718 PMCID: PMC10185548 DOI: 10.1038/s42003-023-04791-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Accepted: 03/31/2023] [Indexed: 05/17/2023] Open
Abstract
Despite decades of genetic studies on late-onset Alzheimer's disease, the underlying molecular mechanisms remain unclear. To better comprehend its complex etiology, we use an integrative approach to build robust predictive (causal) network models using two large human multi-omics datasets. We delineate bulk-tissue gene expression into single cell-type gene expression and integrate clinical and pathologic traits, single nucleotide variation, and deconvoluted gene expression for the construction of cell type-specific predictive network models. Here, we focus on neuron-specific network models and prioritize 19 predicted key drivers modulating Alzheimer's pathology, which we then validate by knockdown in human induced pluripotent stem cell-derived neurons. We find that neuronal knockdown of 10 of the 19 targets significantly modulates levels of amyloid-beta and/or phosphorylated tau peptides, most notably JMJD6. We also confirm our network structure by RNA sequencing in the neurons following knockdown of each of the 10 targets, which additionally predicts that they are upstream regulators of REST and VGF. Our work thus identifies robust neuronal key drivers of the Alzheimer's-associated network state which may represent therapeutic targets with relevance to both amyloid and tau pathology in Alzheimer's disease.
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Affiliation(s)
- Julie P Merchant
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Neuroscience Graduate Group, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Kuixi Zhu
- The Center for Innovation in Brain Sciences, University of Arizona, Tucson, AZ, USA
| | - Marc Y R Henrion
- Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, Pembroke Place, L3 5QA, UK
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, PO Box 30096, Blantyre, Malawi
| | - Syed S A Zaidi
- The Center for Innovation in Brain Sciences, University of Arizona, Tucson, AZ, USA
| | - Branden Lau
- The Center for Innovation in Brain Sciences, University of Arizona, Tucson, AZ, USA
- Arizona Research Labs, Genetics Core, University of Arizona, Tucson, AZ, USA
| | - Sara Moein
- The Center for Innovation in Brain Sciences, University of Arizona, Tucson, AZ, USA
| | - Melissa L Alamprese
- The Center for Innovation in Brain Sciences, University of Arizona, Tucson, AZ, USA
| | - Richard V Pearse
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - David A Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Nilüfer Ertekin-Taner
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, USA
- Department of Neurology, Mayo Clinic Florida, Jacksonville, FL, USA
| | - Tracy L Young-Pearse
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
- Harvard Stem Cell Institute, Harvard University, Boston, MA, USA.
| | - Rui Chang
- The Center for Innovation in Brain Sciences, University of Arizona, Tucson, AZ, USA.
- Department of Neurology, University of Arizona, Tucson, AZ, USA.
- INTelico Therapeutics LLC, Tucson, AZ, USA.
- PATH Biotech LLC, Tucson, AZ, USA.
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15
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Sasso JM, Ammar RM, Tenchov R, Lemmel S, Kelber O, Grieswelle M, Zhou QA. Gut Microbiome-Brain Alliance: A Landscape View into Mental and Gastrointestinal Health and Disorders. ACS Chem Neurosci 2023; 14:1717-1763. [PMID: 37156006 DOI: 10.1021/acschemneuro.3c00127] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/10/2023] Open
Abstract
Gut microbiota includes a vast collection of microorganisms residing within the gastrointestinal tract. It is broadly recognized that the gut and brain are in constant bidirectional communication, of which gut microbiota and its metabolic production are a major component, and form the so-called gut microbiome-brain axis. Disturbances of microbiota homeostasis caused by imbalance in their functional composition and metabolic activities, known as dysbiosis, cause dysregulation of these pathways and trigger changes in the blood-brain barrier permeability, thereby causing pathological malfunctions, including neurological and functional gastrointestinal disorders. In turn, the brain can affect the structure and function of gut microbiota through the autonomic nervous system by regulating gut motility, intestinal transit and secretion, and gut permeability. Here, we examine data from the CAS Content Collection, the largest collection of published scientific information, and analyze the publication landscape of recent research. We review the advances in knowledge related to the human gut microbiome, its complexity and functionality, its communication with the central nervous system, and the effect of the gut microbiome-brain axis on mental and gut health. We discuss correlations between gut microbiota composition and various diseases, specifically gastrointestinal and mental disorders. We also explore gut microbiota metabolites with regard to their impact on the brain and gut function and associated diseases. Finally, we assess clinical applications of gut-microbiota-related substances and metabolites with their development pipelines. We hope this review can serve as a useful resource in understanding the current knowledge on this emerging field in an effort to further solving of the remaining challenges and fulfilling its potential.
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Affiliation(s)
- Janet M Sasso
- CAS, a division of the American Chemical Society, 2540 Olentangy River Rd, Columbus, Ohio 43202, United States
| | - Ramy M Ammar
- Bayer Consumer Health, R&D Digestive Health, Darmstadt 64295, Germany
| | - Rumiana Tenchov
- CAS, a division of the American Chemical Society, 2540 Olentangy River Rd, Columbus, Ohio 43202, United States
| | - Steven Lemmel
- CAS, a division of the American Chemical Society, 2540 Olentangy River Rd, Columbus, Ohio 43202, United States
| | - Olaf Kelber
- Bayer Consumer Health, R&D Digestive Health, Darmstadt 64295, Germany
| | - Malte Grieswelle
- Bayer Consumer Health, R&D Digestive Health, Darmstadt 64295, Germany
| | - Qiongqiong Angela Zhou
- CAS, a division of the American Chemical Society, 2540 Olentangy River Rd, Columbus, Ohio 43202, United States
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16
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Niu H, Li T, Du Y, Lv Z, Cao Q, Zhang Y. Glutamate Transporters GltS, GltP and GltI Are Involved in Escherichia coli Tolerance In Vitro and Pathogenicity in Mouse Urinary Tract Infections. Microorganisms 2023; 11:1173. [PMID: 37317147 DOI: 10.3390/microorganisms11051173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 04/02/2023] [Accepted: 04/09/2023] [Indexed: 06/16/2023] Open
Abstract
To verify the roles of GltS, GltP, and GltI in E. coli tolerance and pathogenicity, we quantified and compared the relative abundance of gltS, gltP, and gltI in log-phase and stationary-phase E. coli and constructed their knockout mutant strains in E. coli BW25113 and uropathogenic E. coli (UPEC) separately, followed by analysis of their abilities to tolerate antibiotics and stressors, their capacity for adhesion to and invasion of human bladder epithelial cells, and their survival ability in mouse urinary tracts. Our results showed that gltS, gltP, and gltI transcripts were higher in stationary phase E. coli than in log-phase incubation. Furthermore, deletion of gltS, gltP, and gltI genes in E. coli BW25113 results in decreased tolerance to antibiotics (levofloxacin and ofloxacin) and stressors (acid pH, hyperosmosis, and heat), and loss of gltS, gltP, and gltI in uropathogenic E. coli UTI89 caused attenuated adhesion and invasion in human bladder epithelial cells and markedly reduced survival in mice. The results showed the important roles of the glutamate transporter genes gltI, gltP, and gltS in E. coli tolerance to antibiotics (levofloxacin and ofloxacin) and stressors (acid pH, hyperosmosis, and heat) in vitro and in pathogenicity in mouse urinary tracts and human bladder epithelial cells, as shown by reduced survival and colonization, which improves our understanding of the molecular mechanisms of bacterial tolerance and pathogenicity.
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Affiliation(s)
- Hongxia Niu
- School of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China
- School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Tuodi Li
- School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Yunjie Du
- School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Zhuoxuan Lv
- School of Basic Medical Sciences, Zhejiang Chinese Medical University, Hangzhou 310053, China
| | - Qianqian Cao
- School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, China
| | - Ying Zhang
- The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310053, China
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17
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Xu J, Guo L, Zhao N, Meng X, Zhang J, Wang T, Wei X, Fan M. Response mechanisms to acid stress of acid-resistant bacteria and biotechnological applications in the food industry. Crit Rev Biotechnol 2023; 43:258-274. [PMID: 35114869 DOI: 10.1080/07388551.2021.2025335] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Acid-resistant bacteria are more and more widely used in industrial production due to their unique acid-resistant properties. In order to survive in various acidic environments, acid-resistant bacteria have developed diverse protective mechanisms such as sensing acid stress and signal transduction, maintaining intracellular pH homeostasis by controlling the flow of H+, protecting and repairing biological macromolecules, metabolic modification, and cross-protection. Acid-resistant bacteria have broad biotechnological application prospects in the food field. The production of fermented foods with high acidity and acidophilic enzymes are the main applications of this kind of bacteria in the food industry. Their acid resistance modules can also be used to construct acid-resistant recombinant engineering strains for special purposes. However, they can also cause negative effects on foods, such as spoilage and toxicity. Herein, the aim of this paper is to summarize the research progress of molecular mechanisms against acid stress of acid-resistant bacteria. Moreover, their effects on the food industry were also discussed. It is useful to lay a foundation for broadening our understanding of the physiological metabolism of acid-resistant bacteria and better serving the food industry.
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Affiliation(s)
- Junnan Xu
- College of Food Science and Engineering, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Li Guo
- College of Food Science and Engineering, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Ning Zhao
- College of Food Science and Engineering, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Xuemei Meng
- College of Food Science and Engineering, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Jie Zhang
- College of Food Science and Engineering, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Tieru Wang
- College of Food Science and Engineering, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Xinyuan Wei
- College of Food Science and Engineering, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
| | - Mingtao Fan
- College of Food Science and Engineering, Northwest Agriculture and Forestry University, Yangling, Shaanxi, China
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18
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Yang L, Zhang X, Chen J, Zhang Y, Feng Z. Expanding the pH range of glutamate decarboxylase from L. pltarum LC84 by site-directed mutagenesis. Front Bioeng Biotechnol 2023; 11:1160818. [PMID: 37122870 PMCID: PMC10133459 DOI: 10.3389/fbioe.2023.1160818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 03/30/2023] [Indexed: 05/02/2023] Open
Abstract
Introduction: Glutamate decarboxylase is a class Ⅱ amino acid decarboxylase dependent onpyridoxal-5'-phosphate (PLP), which catalyzes the decarboxylation of substrateL-glutamate (L-Glu) to synthesize γ-aminobutyric acid (GABA). The low activity ofglutamic acid decarboxylase (GAD) and its ability to catalyze only under acidicconditions limit its application in biosynthesis of GABA. Methods: Taking glutamic acid decarboxylase from Lactobacillus plantarum, which produces GABA, as the research object, the mutation site was determined by amino acid sequence analysis of GAD, the mutation was introduced by primers, and the mutant was constructed by whole plasmid PCR and expressed in Escherichia coli. Then, the enzymatic properties of the mutant were analyzed. Finally, the three-dimensional structure of the mutant was simulated to support the experimental results. Results and Discussion: In this case, mutants E313S and Q347H of glutamate decarboxylase from L. pltarum LC84 (LpGAD) were constructed by targeted mutagenesis. Compared with the wild-type, their enzyme activity increased by 62.4% and 12.0% at the optimum pH 4.8, respectively. In the range of pH 4.0-7.0, their enzyme activity was higher than that of the wild-type, and enzyme activity of mutant E313S was 5 times that of the wild-type at pH 6.2. Visualization software PyMOL analyzed the 3D structure of the mutant predicted by homologous modeling, and the results showed that mutant E313S may broadened the reaction pH of LpGAD through the influence of surface charge, while mutant Q347H may broadened the reaction pH of LpGAD through the stacking effect of aromatic rings. In a word, mutants E313S and Q347H were improved the enzyme activity and were broadened the reaction pH of the enzyme, which made it possible for it to be applied in food industry and laid the foundation for the industrial production of GABA.
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Affiliation(s)
- Lijuan Yang
- College of Bioengineering, Sichuan University of Science and Engineering, Yinbin, China
- Liquor Making Bio-Technology and Application of Key Laboratory of Sichuan Province, Sichuan University of Science and Engineering, Yibin, China
| | - Xian Zhang
- College of Bioengineering, Sichuan University of Science and Engineering, Yinbin, China
| | - Jing Chen
- Faculty of Quality Management and Inspection and Quarantine, Yibin University, Yibin, China
| | - Yao Zhang
- College of Bioengineering, Sichuan University of Science and Engineering, Yinbin, China
| | - Zhiping Feng
- College of Bioengineering, Sichuan University of Science and Engineering, Yinbin, China
- Liquor Making Bio-Technology and Application of Key Laboratory of Sichuan Province, Sichuan University of Science and Engineering, Yibin, China
- *Correspondence: Zhiping Feng,
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19
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Schwarz J, Schumacher K, Brameyer S, Jung K. Bacterial battle against acidity. FEMS Microbiol Rev 2022; 46:6652135. [PMID: 35906711 DOI: 10.1093/femsre/fuac037] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 07/11/2022] [Accepted: 07/27/2022] [Indexed: 01/09/2023] Open
Abstract
The Earth is home to environments characterized by low pH, including the gastrointestinal tract of vertebrates and large areas of acidic soil. Most bacteria are neutralophiles, but can survive fluctuations in pH. Herein, we review how Escherichia, Salmonella, Helicobacter, Brucella, and other acid-resistant Gram-negative bacteria adapt to acidic environments. We discuss the constitutive and inducible defense mechanisms that promote survival, including proton-consuming or ammonia-producing processes, cellular remodeling affecting membranes and chaperones, and chemotaxis. We provide insights into how Gram-negative bacteria sense environmental acidity using membrane-integrated and cytosolic pH sensors. Finally, we address in more detail the powerful proton-consuming decarboxylase systems by examining the phylogeny of their regulatory components and their collective functionality in a population.
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Affiliation(s)
- Julia Schwarz
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
| | - Kilian Schumacher
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
| | - Sophie Brameyer
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
| | - Kirsten Jung
- Faculty of Biology, Microbiology, Ludwig-Maximilians-University München, Großhaderner Str. 2-4, 82152 Martinsried, Germany
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20
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Liu S, Wen B, Du G, Wang Y, Ma X, Yu H, Zhang J, Fan S, Zhou H, Xin F. Coordinated regulation of Bacteroides thetaiotaomicron glutamate decarboxylase activity by multiple elements under different pH. Food Chem 2022; 403:134436. [DOI: 10.1016/j.foodchem.2022.134436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 09/14/2022] [Accepted: 09/25/2022] [Indexed: 11/28/2022]
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21
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Kim H, Jeon S, Kim J, Seol D, Jo J, Cho S, Kim H. Investigation of memory-enhancing effects of Streptococcus thermophilus EG007 in mice and elucidating molecular and metagenomic characteristics using nanopore sequencing. Sci Rep 2022; 12:13274. [PMID: 35918353 PMCID: PMC9346115 DOI: 10.1038/s41598-022-14837-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Accepted: 06/13/2022] [Indexed: 11/15/2022] Open
Abstract
Over the past decades, accumulating evidences have highlighted the gut microbiota as a key player in the brain functioning via microbiota–gut–brain axis, and accordingly, the beneficial role of several probiotic strains in cognitive ability also have been actively investigated. However, the majority of the research have demonstrated the effects against age-related cognitive decline or neurological disease. To this end, we aimed to investigate lactic acid bacteria strains having beneficial effects on the cognitive function of healthy young mice and elucidate underlying characteristics by carrying out nanopore sequencing-based genomics and metagenomics analysis. 8-week consumption of Streptococcus thermophilus EG007 demonstrated marked enhancements in behavior tests assessing short-term spatial and non-spatial learning and memory. It was revealed that EG007 possessed genes encoding various metabolites beneficial for a health condition in many aspects, including gamma-aminobutyric acid producing system, a neurotransmitter associated with mood and stress response. Also, by utilizing 16S–23S rRNA operon as a taxonomic marker, we identified more accurate species-level compositional changes in gut microbiota, which was increase of certain species, previously reported to have associations with mental health or down-regulation of inflammation or infection-related species. Moreover, correlation analysis revealed that the EG007-mediated altered microbiota had a significant correlation with the memory traits.
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Affiliation(s)
- Hyaekang Kim
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Soomin Jeon
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jina Kim
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Donghyeok Seol
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea.,eGnome, Inc, Seoul, Republic of Korea
| | - JinChul Jo
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea
| | - Seoae Cho
- eGnome, Inc, Seoul, Republic of Korea
| | - Heebal Kim
- Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 08826, Republic of Korea. .,eGnome, Inc, Seoul, Republic of Korea.
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22
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Gu X, Zhang R, Zhao J, Li C, Guo T, Yang S, Han T, Kong J. Fast-acidification promotes GABA synthesis in response to acid stress in Streptococcus thermophilus. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2022.113671] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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23
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Bourebaba Y, Marycz K, Mularczyk M, Bourebaba L. Postbiotics as potential new therapeutic agents for metabolic disorders management. Biomed Pharmacother 2022; 153:113138. [PMID: 35717780 DOI: 10.1016/j.biopha.2022.113138] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/07/2022] [Accepted: 05/15/2022] [Indexed: 11/24/2022] Open
Abstract
The prevalence of obesity, diabetes, non-alcoholic fatty liver disease, and related metabolic disorders has been steadily increasing in the past few decades. Apart from the establishment of caloric restrictions in combination with improved physical activity, there are no effective pharmacological treatments for most metabolic disorders. Many scientific-studies have described various beneficial effects of probiotics in regulating metabolism but others questioned their effectiveness and safety. Postbiotics are defined as preparation of inanimate microorganisms, and/or their components, which determine their safety of use and confers a health benefit to the host. Additionally, unlike probiotics postbiotics do not require stringent production/storage conditions. Recently, many lines of evidence demonstrated that postbiotics may be beneficial in metabolic disorders management via several potential effects including anti-inflammatory, antibacterial, immunomodulatory, anti-carcinogenic, antioxidant, antihypertensive, anti-proliferative, and hypocholesterolaemia properties that enhance both the immune system and intestinal barrier functions by acting directly on specific tissues of the intestinal epithelium, but also on various organs or tissues. In view of the many reports that demonstrated the high biological activity and safety of postbiotics, we summarized in the present review the current findings reporting the beneficial effects of various probiotics derivatives for the management of metabolic disorders and related alterations.
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Affiliation(s)
- Yasmina Bourebaba
- Laboratoire de Biomathématique, Biophysique, Biochimie et Scientométrie (L3BS), Faculté des Sciences de la Nature et de la Vie, Université de Bejaia, 06000 Bejaia, Algeria.
| | - Krzysztof Marycz
- Department of Experimental Biology, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Sciences, Norwida 27B, 50-375 Wrocław, Poland; Department of Medicine and Epidemiology, UC Davis School of Veterinary Medicine, Davis, CA 95516, USA
| | - Malwina Mularczyk
- Department of Experimental Biology, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Sciences, Norwida 27B, 50-375 Wrocław, Poland; International Institute of Translational Medicine, Jesionowa, 11, Malin, 55-114 Wisznia Mała, Poland
| | - Lynda Bourebaba
- Department of Experimental Biology, Faculty of Biology and Animal Science, Wrocław University of Environmental and Life Sciences, Norwida 27B, 50-375 Wrocław, Poland; International Institute of Translational Medicine, Jesionowa, 11, Malin, 55-114 Wisznia Mała, Poland.
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The Retrospective on Atypical Brucella Species Leads to Novel Definitions. Microorganisms 2022; 10:microorganisms10040813. [PMID: 35456863 PMCID: PMC9025488 DOI: 10.3390/microorganisms10040813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 02/01/2023] Open
Abstract
The genus Brucella currently comprises twelve species of facultative intracellular bacteria with variable zoonotic potential. Six of them have been considered as classical, causing brucellosis in terrestrial mammalian hosts, with two species originated from marine mammals. In the past fifteen years, field research as well as improved pathogen detection and typing have allowed the identification of four new species, namely Brucella microti, Brucella inopinata, Brucella papionis, Brucella vulpis, and of numerous strains, isolated from a wide range of hosts, including for the first time cold-blooded animals. While their genome sequences are still highly similar to those of classical strains, some of them are characterized by atypical phenotypes such as higher growth rate, increased resistance to acid stress, motility, and lethality in the murine infection model. In our review, we provide an overview of state-of-the-art knowledge about these novel Brucella sp., with emphasis on their phylogenetic positions in the genus, their metabolic characteristics, acid stress resistance mechanisms, and their behavior in well-established in cellulo and in vivo infection models. Comparison of phylogenetic classification and phenotypical properties between classical and novel Brucella species and strains finally lead us to propose a more adapted terminology, distinguishing between core and non-core, and typical versus atypical brucellae, respectively.
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Division of labor and collective functionality in Escherichia coli under acid stress. Commun Biol 2022; 5:327. [PMID: 35393532 PMCID: PMC8989999 DOI: 10.1038/s42003-022-03281-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 03/03/2022] [Indexed: 11/09/2022] Open
Abstract
The acid stress response is an important factor influencing the transmission of intestinal microbes such as the enterobacterium Escherichia coli. E. coli activates three inducible acid resistance systems - the glutamate decarboxylase, arginine decarboxylase, and lysine decarboxylase systems to counteract acid stress. Each system relies on the activity of a proton-consuming reaction catalyzed by a specific amino acid decarboxylase and a corresponding antiporter. Activation of these three systems is tightly regulated by a sophisticated interplay of membrane-integrated and soluble regulators. Using a fluorescent triple reporter strain, we quantitatively illuminated the cellular individuality during activation of each of the three acid resistance (AR) systems under consecutively increasing acid stress. Our studies highlight the advantages of E. coli in possessing three AR systems that enable division of labor in the population, which ensures survival over a wide range of low pH values.
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Characterization and mutagenesis of a novel Mycobacterium smegmatis-derived glutamate decarboxylase active at neutral pH. World J Microbiol Biotechnol 2022; 38:75. [PMID: 35298707 DOI: 10.1007/s11274-022-03252-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Accepted: 02/17/2022] [Indexed: 10/18/2022]
Abstract
γ-aminobutyric acid (GABA) has various physiological functions and is widely used in medicine, food, and other fields. Glutamate decarboxylase (GAD) is a key enzyme that catalyzes the decarboxylation of L-glutamate to synthesize GABA. However, the industrial application of microorganism-derived GAD is limited by its rapid loss of enzymatic activity with pH approaching neutrality. In this study, a novel glutamate decarboxylase, GADMSM, from Mycobacterium smegmatis was overexpressed and purified. On the basis of homologous modeling and substrate molecular docking, several GADMSM mutants were constructed, and their enzymatic properties were analyzed. The results showed that the optimal pH of wild-type GADMSM is 5.4; at pH 6.2, 22.8% enzymatic activity was retained. The T211I replacement in GAD and C-terminal deletion mutant GADMSMΔC showed relatively high catalytic activity in a pH range of 5.0-7.0. The Vmax and Km values of GADMSMΔC were 14.69 and 5.70, respectively, at pH 5.5, and 9.87 and 6.17, respectively, at pH 7.0. Compared with the wild-type GAD, GADMSMΔC maintained higher affinity and enzymatic activity of the substrate, maintaining 78.5% of the highest enzymatic activity even at pH 7.0, which is the highest reported activity retention for GAD under neutral pH condition. Therefore, GADMSMΔC can be used for the transformation of high-yielding strains and industrial production of GABA.
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Bendiks ZA, Guice J, Coulon D, Raggio AM, Page RC, Carvajal-Aldaz DG, Luo M, Welsh DA, Marx BD, Taylor CM, Husseneder C, Keenan MJ, Marco ML. Resistant starch type 2 and whole grain maize flours enrich different intestinal bacteria and metatranscriptomes. J Funct Foods 2022. [DOI: 10.1016/j.jff.2022.104982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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Schwan WR, Luedtke J, Engelbrecht K, Mollinger J, Wheaton A, Foster JW, Wolchak R. Regulation of Escherichia coli fim gene transcription by GadE and other acid tolerance gene products. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001149. [PMID: 35316170 PMCID: PMC9558354 DOI: 10.1099/mic.0.001149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 01/26/2022] [Indexed: 11/18/2022]
Abstract
Uropathogenic Escherichia coli (UPEC) cause millions of urinary tract infections each year in the United States. Type 1 pili are important for adherence of UPEC to uroepithelial cells in the human and murine urinary tracts where osmolality and pH vary. Previous work has shown that an acidic pH adversely affects the expression of type 1 pili. To determine if acid tolerance gene products may be regulating E. coli fim gene expression, a bank of K-12 strain acid tolerance gene mutants were screened using fimA-lux, fimB-lux, and fimE-lux fusions on single copy number plasmids. We have determined that a mutation in gadE increased transcription of all three fim genes, suggesting that GadE may be acting as a repressor in a low pH environment. Complementation of the gadE mutation restored fim gene transcription to wild-type levels. Moreover, mutations in gadX, gadW, crp, and cya also affected transcription of the three fim genes. To verify the role GadE plays in type 1 pilus expression, the NU149 gadE UPEC strain was tested. The gadE mutant had higher fimE gene transcript levels, a higher frequency of Phase-OFF positioning of fimS, and hemagglutination titres that were lower in strain NU149 gadE cultured in low pH medium as compared to the wild-type bacteria. The data demonstrate that UPEC fim genes are regulated directly or indirectly by the GadE protein and this could have some future bearing on the ability to prevent urinary tract infections by acidifying the urine and shutting off fim gene expression.
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Affiliation(s)
| | | | | | | | | | - John W. Foster
- University South Alabama College of Medicine, Mobile, AL, USA
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Kim J, Yoon YW, Kim MS, Lee MH, Kim GA, Bae K, Yoon SS. Gamma-aminobutyric acid fermentation in MRS-based medium by the fructophilic Lactiplantibacillus plantarum Y7. Food Sci Biotechnol 2022; 31:333-341. [PMID: 35273823 PMCID: PMC8885955 DOI: 10.1007/s10068-022-01035-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/17/2022] [Accepted: 01/20/2022] [Indexed: 02/06/2023] Open
Abstract
Among the key metabolites produced by probiotic lactic acid bacteria (LAB), the use of gamma-aminobutyric acid (GABA), which alleviates hypertension, depression, and sleepiness in humans, is gaining popularity. Thus, GABA-producing LAB are sought after. GABA-producing LAB were preliminarily screened in acidified-MRS broth and quantified via GABase assays. The one-factor-at-a-time strategy was applied to determine the optimal conditions for GABA production. GABA production in reconstituted skim milk medium (RSM) and antibiotic susceptibility testing were performed to evaluate the potential of the strain as a yogurt starter. L. plantarum Y7 produced 4,856.86 ± 82.47 μg/mL of GABA at optimal culture conditions. Co-cultivation of Y7 and commercial Lactobacillus bulgaricus affected the amount of GABA production (6.85 ± 0.20 μg/mL) in RSM. Y7 was susceptible to ampicillin, erythromycin, and tetracycline. Therefore, L. plantarum Y7 represents a promising strain for GABA production in the food industry.
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Affiliation(s)
- Jaegon Kim
- Department of Biological Science and Technology, Yonsei University, 1 Yeonsedae-gil, Heungeop-myeon, Wonju-si, Gangwon-do 26493 Republic of Korea
| | - Yong-Won Yoon
- Department of Biological Science and Technology, Yonsei University, 1 Yeonsedae-gil, Heungeop-myeon, Wonju-si, Gangwon-do 26493 Republic of Korea
| | - Min-Sun Kim
- Department of Biological Science and Technology, Yonsei University, 1 Yeonsedae-gil, Heungeop-myeon, Wonju-si, Gangwon-do 26493 Republic of Korea
| | - Myung-Hyun Lee
- Department of Biological Science and Technology, Yonsei University, 1 Yeonsedae-gil, Heungeop-myeon, Wonju-si, Gangwon-do 26493 Republic of Korea
| | - Geun-Ah Kim
- Department of Biological Science and Technology, Yonsei University, 1 Yeonsedae-gil, Heungeop-myeon, Wonju-si, Gangwon-do 26493 Republic of Korea
| | - Kiho Bae
- Division of Biological Science and Technology, Yonsei University, Wonju, Republic of Korea
| | - Sung-Sik Yoon
- Department of Biological Science and Technology, Yonsei University, 1 Yeonsedae-gil, Heungeop-myeon, Wonju-si, Gangwon-do 26493 Republic of Korea
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Engineering the Outer Membrane Could Facilitate Better Bacterial Performance and Effectively Enhance Poly-3-Hydroxybutyrate Accumulation. Appl Environ Microbiol 2021; 87:e0138921. [PMID: 34550763 DOI: 10.1128/aem.01389-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Poly-3-hydroxybutyrate (PHB) is an environmentally friendly polymer and can be produced in Escherichia coli cells after overexpression of the heterologous gene cluster phaCAB. The biosynthesis of the outer membrane (OM) consumes many nutrients and influences cell morphology. Here, we engineered the OM by disrupting all gene clusters relevant to the polysaccharide portion of lipopolysaccharide (LPS), colanic acid (CA), flagella, and/or fimbria in E. coli W3110. All these disruptions benefited PHB production. Especially, disrupting all these OM components increased the PHB content to 83.0 wt% (PHB content percentage of dry cell weight), while the wild-type control produced only 1.5 wt% PHB. The increase was mainly due to the LPS truncation to Kdo2 (3-deoxy-d-manno-octulosonic acid)-lipid A, which resulted in 82.0 wt% PHB with a 25-fold larger cell volume, and disrupting CA resulted in 57.8 wt% PHB. In addition, disrupting LPS facilitated advantageous fermentation features, including 69.1% less acetate, a 550% higher percentage of autoaggregated cells among the total culture cells, 69.1% less biofilm, and a higher broken cell ratio. Further detailed mechanism investigations showed that disrupting LPS caused global changes in envelope and cellular metabolism: (i) a sharp decrease in flagella, fimbria, and secretions; (ii) more elastic cells; (iii) much greater carbon flux toward acetyl coenzyme A (acetyl-CoA) and supply of cofactors, including NADP, NAD, and ATP; and (iv) a decrease in by-product acids but increase in γ-aminobutyric acid by activating σE factor. Disrupting CA, flagella, and fimbria also improved the levels of acetyl-CoA and cofactors. The results indicate that engineering the OM is an effective strategy to enhance PHB production and highlight the applicability of OM engineering to increase microbial cell factory performance. IMPORTANCE Understanding the detailed influence of the OM on the cell envelope and cellular metabolism is important for optimizing the E. coli cell factory and many other microorganisms. This study revealed the applicability of remodeling the OM to enhance PHB accumulation as representative inclusion bodies. The results generated in this study give essential information for producing other inclusion bodies or chemicals which need more acetyl-CoA and cofactors but less by-product acids. This study is promising to provide new ideas for the improvement of microbial cell factories.
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Gu X, Zhao J, Zhang R, Yu R, Guo T, Kong J. Molecular Analysis of Glutamate Decarboxylases in Enterococcus avium. Front Microbiol 2021; 12:691968. [PMID: 34566904 PMCID: PMC8461050 DOI: 10.3389/fmicb.2021.691968] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/23/2021] [Indexed: 11/13/2022] Open
Abstract
Enterococcus avium (E. avium) is a common bacterium inhabiting the intestines of humans and other animals. Most strains of this species can produce gamma-aminobutyric acid (GABA) via the glutamate decarboxylase (GAD) system, but the presence and genetic organization of their GAD systems are poorly characterized. In this study, our bioinformatics analyses showed that the GAD system in E. avium strains was generally encoded by three gadB genes (gadB1, gadB2, and gadB3), together with an antiporter gene (gadC) and regulator gene (gadR), and these genes are organized in a cluster. This finding contrasts with that for other lactic acid bacteria. E. avium SDMCC050406, a GABA producer isolated from human feces, was employed to investigate the contribution of the three gadB genes to GABA biosynthesis. The results showed that the relative expression level of gadB3 was higher than those of gadB1 and gadB2 in the exponential growth and stationary phases, and this was accompanied by the synchronous transcription of gadC. After heterologous expression of the three gadB genes in Escherichia coli BL21 (DE3), the Km value of the purified GAD3 was 4.26 ± 0.48 mM, a value lower than those of the purified GAD1 and GAD2. Moreover, gadB3 gene inactivation caused decreased GABA production, accompanied by a reduction in resistance to acid stress. These results indicated that gadB3 plays a crucial role in GABA biosynthesis and this property endowed the strain with acid tolerance. Our findings provided insights into how E. avium strains survive the acidic environments of fermented foods and throughout transit through the stomach and gut while maintaining cell viability.
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Affiliation(s)
- Xinyi Gu
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Jiancun Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Rongling Zhang
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Ruohan Yu
- College of Food Science and Engineering, Shandong Agricultural University, Tai'an, China
| | - Tingting Guo
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
| | - Jian Kong
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao, China
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Ribeiro S, Mourão J, Novais Â, Campos J, Peixe L, Antunes P. From farm to fork: Colistin voluntary withdrawal in Portuguese farms reflected in decreasing occurrence of mcr-1-carrying Enterobacteriaceae from chicken meat. Environ Microbiol 2021; 23:7563-7577. [PMID: 34327794 DOI: 10.1111/1462-2920.15689] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 07/27/2021] [Indexed: 11/27/2022]
Abstract
Expansion of mcr-carrying Enterobacteriaceae (MCR-E) is a well-recognized problem affecting animals, humans and the environment. Ongoing global control actions involve colistin restrictions among food-animal production, but their impact on poultry-derived products is largely unknown, justifying comprehensive farm-to-fork studies. Occurrence of MCR-E among 53 chicken-meat batches supplied from 29 Portuguese farms shortly after colistin withdrawal was evaluated. Strains (FT-IR/MLST/WGS), mcr plasmids and their adaptive features were characterized by cultural, molecular and genomic approaches. We found high rates of chicken-meat batches (80%-100% - 4 months; 12% - the last month) with multiple MDR + mcr-1-carrying Escherichia coli (Ec-including ST117 and ST648-Cplx) and Klebsiella pneumoniae (Kp-ST147-O5:K35) clones, some of them persisting over time. The mcr-1 was located in the chromosome (Ec-ST297/16-farms) or dispersed IncX4 (Ec-ST602/ST6469/5-farms), IncHI2-ST2/ST4 (Ec-ST533/ST6469/5 farms and Kp-ST147/6-farms) or IncI2 (Ec-ST117/1-farm) plasmids. WGS revealed high load and diversity in virulence, antibiotic resistance and metal tolerance genes. This study supports colistin withdrawal potential efficacy in poultry production and highlights both poultry-production chain as a source of mcr-1 and the risk of foodborne transmission to poultry-meat consumers. Finally, in the antibiotic reduction/replacement context, other potential co-selective pressures (e.g., metals-Cu as feed additives) need to be further understood to guide concerted, effective and durable actions under 'One Health' perspective.
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Affiliation(s)
- Sofia Ribeiro
- UCIBIO - Applied Molecular Biosciences Unit, REQUIMTE, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, 4050-313, Portugal
| | - Joana Mourão
- UCIBIO - Applied Molecular Biosciences Unit, REQUIMTE, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, 4050-313, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Ângela Novais
- UCIBIO - Applied Molecular Biosciences Unit, REQUIMTE, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, 4050-313, Portugal.,Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, 4050-313, Portugal
| | - Joana Campos
- UCIBIO - Applied Molecular Biosciences Unit, REQUIMTE, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, 4050-313, Portugal.,INEB-Institute of Biomedical Engineering, i3S-Institute for Research & Innovation in Health, University of Porto, Porto, Portugal
| | - Luísa Peixe
- UCIBIO - Applied Molecular Biosciences Unit, REQUIMTE, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, 4050-313, Portugal.,Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, 4050-313, Portugal
| | - Patrícia Antunes
- UCIBIO - Applied Molecular Biosciences Unit, REQUIMTE, Laboratory of Microbiology, Department of Biological Sciences, Faculty of Pharmacy, University of Porto, Porto, 4050-313, Portugal.,Associate Laboratory i4HB - Institute for Health and Bioeconomy, Faculty of Pharmacy, University of Porto, Porto, 4050-313, Portugal.,Faculty of Nutrition and Food Sciences, University of Porto, Porto, 4150-180, Portugal
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Sheikh SW, Ali A, Ahsan A, Shakoor S, Shang F, Xue T. Insights into Emergence of Antibiotic Resistance in Acid-Adapted Enterohaemorrhagic Escherichia coli. Antibiotics (Basel) 2021; 10:antibiotics10050522. [PMID: 34063307 PMCID: PMC8147483 DOI: 10.3390/antibiotics10050522] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 04/15/2021] [Accepted: 04/29/2021] [Indexed: 12/17/2022] Open
Abstract
The emergence of multidrug-resistant pathogens presents a global challenge for treating and preventing disease spread through zoonotic transmission. The water and foodborne Enterohaemorrhagic Escherichia coli (EHEC) are capable of causing intestinal and systemic diseases. The root cause of the emergence of these strains is their metabolic adaptation to environmental stressors, especially acidic pH. Acid treatment is desired to kill pathogens, but the protective mechanisms employed by EHECs cross-protect against antimicrobial peptides and thus facilitate opportunities for survival and pathogenesis. In this review, we have discussed the correlation between acid tolerance and antibiotic resistance, highlighting the identification of novel targets for potential production of antimicrobial therapeutics. We have also summarized the molecular mechanisms used by acid-adapted EHECs, such as the two-component response systems mediating structural modifications, competitive inhibition, and efflux activation that facilitate cross-protection against antimicrobial compounds. Moving beyond the descriptive studies, this review highlights low pH stress as an emerging player in the development of cross-protection against antimicrobial agents. We have also described potential gene targets for innovative therapeutic approaches to overcome the risk of multidrug-resistant diseases in healthcare and industry.
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Affiliation(s)
- Salma Waheed Sheikh
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China;
| | - Ahmad Ali
- School of Agronomy, Anhui Agricultural University, Hefei 230036, China;
| | - Asma Ahsan
- Faculty of Life Sciences, University of Central Punjab, Lahore 54000, Punjab, Pakistan;
| | - Sidra Shakoor
- Station de Neucfchateau, CIRAD, 97130 Sainte-Marie, Capesterre Belle Eau, Guadeloupe, France;
| | - Fei Shang
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China;
- Correspondence: (F.S.); (T.X.); Tel.: +86-551-657-87380 (F.S.); +86-551-657-80690 (T.X.)
| | - Ting Xue
- School of Life Sciences, Anhui Agricultural University, Hefei 230036, China;
- Correspondence: (F.S.); (T.X.); Tel.: +86-551-657-87380 (F.S.); +86-551-657-80690 (T.X.)
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Zhao D, Yang J, Liu T, Lu D, Zhang S, Yan L, Ni Y. Complete Genome Sequence Analysis of Acidithiobacillus ferrivorans XJFY6S-08 Reveals Environmental Adaptation to Alpine Acid Mine Drainage. Curr Microbiol 2021; 78:1488-1498. [PMID: 33660044 DOI: 10.1007/s00284-021-02423-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 02/10/2021] [Indexed: 02/02/2023]
Abstract
The present work reported the complete genome sequence analysis of Acidithiobacillus ferrivorans strain XJFY6S-08 isolated from acid mine drainage in Fuyun copper mine in Xinjiang, China, revealing the potential for extreme environmental adaptation. The strain XJFY6S-08 possesses 3,161,380 bp in length and 56.55% GC content. Genomic analysis revealed that this strain harbors metal-tolerant genes coding for the mer operon, arsRBC operon and a variety of metal assimilation and efflux proteins. Genes coding for K+/H+ transporting ATPase and the Na+/H+ antiporter gene nhaA for pH adaptation were identified. The presence of genes associated with various DNA repair enzymes and the synthesis of mycosporine-like amino acids precursor support the UVR resistance mechanisms. The genes related to membrane modifications (ppiBCD, slyD, surA, cfa and fabF) and resistance-nodulation-division (RND) family can play a crucial role in organic solvents tolerance. The strain XJFY6S-08 resists low-temperature conditions by a set of mechanisms such as changes of RNA metabolism, transmembrane transport, compatible solutes and transport, biofilm and EPS formation, chemotaxis and motility and ROS scavenging. These findings can provide important information for further studying the comparative genome and environmental adaptation mechanism of A. ferrivorans.
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Affiliation(s)
- Dan Zhao
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, 163319, People's Republic of China
| | - Jian Yang
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, 163319, People's Republic of China
| | - Tao Liu
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, 163319, People's Republic of China
| | - Dong Lu
- Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, People's Republic of China
| | - Shuang Zhang
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, 163319, People's Republic of China
| | - Lei Yan
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo-Waste in Cold Region, College of Life Science and Biotechnology, Heilongjiang Bayi Agricultural University, Daqing, 163319, People's Republic of China.
| | - Yongqing Ni
- School of Food Science, Shihezi University, Shihezi, Xinjiang, 832003, People's Republic of China.
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Thuy DTB, Nguyen A, Khoo KS, Chew KW, Cnockaert M, Vandamme P, Ho YC, Huy ND, Cocoletzi HH, Show PL. Optimization of culture conditions for gamma-aminobutyric acid production by newly identified Pediococcus pentosaceus MN12 isolated from 'mam nem', a fermented fish sauce. Bioengineered 2020; 12:54-62. [PMID: 33350336 PMCID: PMC8291785 DOI: 10.1080/21655979.2020.1857626] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
This study was aimed to identify and optimize the culture conditions for gamma-aminobutyric acid (GABA) production by a lactic acid bacterium strain isolated from mam nem, a fermented fish sauce. Among the six isolates obtained from mam nem, the MN12 had the most potent GABA-producing capability. The strain was then identified to be Pedioccocus pentosaceus by employing MALDI-TOF-MS and phenylalanyl-tRNA synthase sequencing methods. The initial cell density of 5.106 CFU/mL, monosodium glutamate concentration of 60 mM, initial pH of 7, temperature of 45°C and cultivation time of 72 h were found to be the optimal culture conditions for highest production of GABA, reaching 27.9 ± 0.42 mM, by this strain. The cultivation conditions for GABA production by P. pentosaceus MN12 have been successfully optimized, providing a foundation for the development of fermented foods enriched with GABA.
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Affiliation(s)
- Do Thi Bich Thuy
- Hue University of Agriculture and Forestry, Hue Universit, Hue , Vietnam
| | - AnTien Nguyen
- Faculty of Agriculture and Forestry, Dalat University , Dalat, Vietnam
| | - Kuan Shiong Khoo
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia , Selangor Darul Ehsan, Malaysia
| | - Kit Wayne Chew
- School of Energy and Chemical Engineering, Xiamen University Malaysia, Jalan Sunsuria, Bandar Sunsuria , Sepang, Selangor, Malaysia
| | - Margo Cnockaert
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Ghent University , Ghent, Belgium
| | - Peter Vandamme
- Laboratory of Microbiology, Department of Biochemistry and Microbiology, Ghent University , Ghent, Belgium
| | - Yeek-Chia Ho
- Civil and Environmental Engineering Department, Universiti Teknologi PETRONAS , Seri Iskandar, Perak Darul Ridzuan, Malaysia.,Centre for Urban Resource Sustainability, Institute of Self-Sustainable Building, Universiti Teknologi PETRONAS , Perak Darul Ridzuan, Malaysia
| | - Nguyen Duc Huy
- Institute of Biotechnology, Hue University, Hue , Vietnam
| | | | - Pau Loke Show
- Department of Chemical and Environmental Engineering, Faculty of Science and Engineering, University of Nottingham Malaysia , Selangor Darul Ehsan, Malaysia
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36
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Yogeswara IBA, Maneerat S, Haltrich D. Glutamate Decarboxylase from Lactic Acid Bacteria-A Key Enzyme in GABA Synthesis. Microorganisms 2020; 8:microorganisms8121923. [PMID: 33287375 PMCID: PMC7761890 DOI: 10.3390/microorganisms8121923] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 01/05/2023] Open
Abstract
Glutamate decarboxylase (l-glutamate-1-carboxylase, GAD; EC 4.1.1.15) is a pyridoxal-5’-phosphate-dependent enzyme that catalyzes the irreversible α-decarboxylation of l-glutamic acid to γ-aminobutyric acid (GABA) and CO2. The enzyme is widely distributed in eukaryotes as well as prokaryotes, where it—together with its reaction product GABA—fulfils very different physiological functions. The occurrence of gad genes encoding GAD has been shown for many microorganisms, and GABA-producing lactic acid bacteria (LAB) have been a focus of research during recent years. A wide range of traditional foods produced by fermentation based on LAB offer the potential of providing new functional food products enriched with GABA that may offer certain health-benefits. Different GAD enzymes and genes from several strains of LAB have been isolated and characterized recently. GABA-producing LAB, the biochemical properties of their GAD enzymes, and possible applications are reviewed here.
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Affiliation(s)
- Ida Bagus Agung Yogeswara
- Food Biotechnology Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences BOKU, Muthgasse 18, 1190 Vienna, Austria;
- Nutrition Department, Faculty of Health, Science and Technology, Universitas Dhyana Pura, Dalung Kuta utara 80361, Bali, Indonesia
- Correspondence:
| | - Suppasil Maneerat
- Faculty of Agro-Industry, Prince of Songkla University, Hat Yai 90110, Songkhla, Thailand;
| | - Dietmar Haltrich
- Food Biotechnology Laboratory, Department of Food Science and Technology, University of Natural Resources and Life Sciences BOKU, Muthgasse 18, 1190 Vienna, Austria;
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Kutscha R, Pflügl S. Microbial Upgrading of Acetate into Value-Added Products-Examining Microbial Diversity, Bioenergetic Constraints and Metabolic Engineering Approaches. Int J Mol Sci 2020; 21:ijms21228777. [PMID: 33233586 PMCID: PMC7699770 DOI: 10.3390/ijms21228777] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 10/29/2020] [Accepted: 11/18/2020] [Indexed: 01/20/2023] Open
Abstract
Ecological concerns have recently led to the increasing trend to upgrade carbon contained in waste streams into valuable chemicals. One of these components is acetate. Its microbial upgrading is possible in various species, with Escherichia coli being the best-studied. Several chemicals derived from acetate have already been successfully produced in E. coli on a laboratory scale, including acetone, itaconic acid, mevalonate, and tyrosine. As acetate is a carbon source with a low energy content compared to glucose or glycerol, energy- and redox-balancing plays an important role in acetate-based growth and production. In addition to the energetic challenges, acetate has an inhibitory effect on microorganisms, reducing growth rates, and limiting product concentrations. Moreover, extensive metabolic engineering is necessary to obtain a broad range of acetate-based products. In this review, we illustrate some of the necessary energetic considerations to establish robust production processes by presenting calculations of maximum theoretical product and carbon yields. Moreover, different strategies to deal with energetic and metabolic challenges are presented. Finally, we summarize ways to alleviate acetate toxicity and give an overview of process engineering measures that enable sustainable acetate-based production of value-added chemicals.
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38
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Cataldo PG, Villegas JM, Savoy de Giori G, Saavedra L, Hebert EM. Enhancement of γ-aminobutyric acid (GABA) production by Lactobacillus brevis CRL 2013 based on carbohydrate fermentation. Int J Food Microbiol 2020; 333:108792. [DOI: 10.1016/j.ijfoodmicro.2020.108792] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/15/2020] [Accepted: 07/14/2020] [Indexed: 12/26/2022]
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39
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Oh JK, Chae JP, Pajarillo EAB, Kim SH, Kwak MJ, Eun JS, Chee SW, Whang KY, Kim SH, Kang DK. Association between the body weight of growing pigs and the functional capacity of their gut microbiota. Anim Sci J 2020; 91:e13418. [PMID: 32648357 DOI: 10.1111/asj.13418] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 05/01/2020] [Accepted: 05/26/2020] [Indexed: 12/20/2022]
Abstract
Gastrointestinal microbiota impact host's biological activities, including digestion of indigestible feed components, energy harvest, and immunity. In this study, fecal microbiota of high body weight (HW) and low body weight (LW) growing pigs at 103 days of age were compared. Principal coordinates analysis separated the HW and LW groups into two clusters, indicating their potential differences between microbial community composition. Although the abundances of two major phyla, Firmicutes and Bacteroidetes, did not significantly differ between the HW and LW groups, some genera showed significant differences. Among them, Peptococcus and Eubacterium exhibited strong positive correlations with body weight (BW) and average daily gain (ADG) (Rho > 0.40), whereas Treponema, Desulfovibrio, Parabacteroides, and Ruminococcaceae_unclassified exhibited strong negative correlations with BW and ADG (Rho < -0.40). Based on these results, the structure of intestinal microbiota may affect growth traits in pigs through host-microbe interactions. Further in-depth studies will provide insights into how best to reshape host-microbe interactions in pigs and other animals as well.
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Affiliation(s)
- Ju Kyoung Oh
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
| | - Jong Pyo Chae
- Biotechnology Research Institute, CJ CheilJedang, Suwon, Republic of Korea
| | | | - Sung Hun Kim
- Biotechnology Research Institute, CJ CheilJedang, Suwon, Republic of Korea
| | - Min-Jin Kwak
- Department of Biotechnology, Korea University, Seoul, Republic of Korea
| | - Jong-Su Eun
- Biotechnology Research Institute, CJ CheilJedang, Suwon, Republic of Korea
| | - Seok Woo Chee
- Biotechnology Research Institute, CJ CheilJedang, Suwon, Republic of Korea
| | - Kwang-Youn Whang
- Department of Biotechnology, Korea University, Seoul, Republic of Korea
| | - Sae-Hun Kim
- Department of Food Bioscience and Technology, Korea University, Seoul, Republic of Korea
| | - Dae-Kyung Kang
- Department of Animal Resources Science, Dankook University, Cheonan, Republic of Korea
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40
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Zhu L, Mack C, Wirtz A, Kranz A, Polen T, Baumgart M, Bott M. Regulation of γ-Aminobutyrate (GABA) Utilization in Corynebacterium glutamicum by the PucR-Type Transcriptional Regulator GabR and by Alternative Nitrogen and Carbon Sources. Front Microbiol 2020; 11:544045. [PMID: 33193127 PMCID: PMC7652997 DOI: 10.3389/fmicb.2020.544045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 09/17/2020] [Indexed: 01/14/2023] Open
Abstract
γ-Aminobutyric acid (GABA) is a non-proteinogenic amino acid mainly formed by decarboxylation of L-glutamate and is widespread in nature from microorganisms to plants and animals. In this study, we analyzed the regulation of GABA utilization by the Gram-positive soil bacterium Corynebacterium glutamicum, which serves as model organism of the phylum Actinobacteria. We show that GABA usage is subject to both specific and global regulatory mechanisms. Transcriptomics revealed that the gabTDP genes encoding GABA transaminase, succinate semialdehyde dehydrogenase, and GABA permease, respectively, were highly induced in GABA-grown cells compared to glucose-grown cells. Expression of the gabTDP genes was dependent on GABA and the PucR-type transcriptional regulator GabR, which is encoded divergently to gabT. A ΔgabR mutant failed to grow with GABA, but not with glucose. Growth of the mutant on GABA was restored by plasmid-based expression of gabR or of gabTDP, indicating that no further genes are specifically required for GABA utilization. Purified GabR (calculated mass 55.75 kDa) formed an octamer with an apparent mass of 420 kDa and bound to two inverted repeats in the gabR-gabT intergenic region. Glucose, gluconate, and myo-inositol caused reduced expression of gabTDP, presumably via the cAMP-dependent global regulator GlxR, for which a binding site is present downstream of the gabT transcriptional start site. C. glutamicum was able to grow with GABA as sole carbon and nitrogen source. Ammonium and, to a lesser extent, urea inhibited growth on GABA, whereas L-glutamine stimulated it. Possible mechanisms for these effects are discussed.
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Affiliation(s)
| | | | | | | | | | - Meike Baumgart
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, Germany
| | - Michael Bott
- IBG-1: Biotechnology, Institute of Bio- and Geosciences, Forschungszentrum Jülich, Jülich, Germany
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41
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De Biase D, Morrissey JP, O'Byrne CP. Editorial: Microbial Stress: From Sensing to Intracellular and Population Responses. Front Microbiol 2020; 11:1667. [PMID: 32849343 PMCID: PMC7411178 DOI: 10.3389/fmicb.2020.01667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 06/25/2020] [Indexed: 12/22/2022] Open
Affiliation(s)
- Daniela De Biase
- Department of Medico-Surgical Sciences and Biotechnologies, Laboratory Affiliated to the Istituto Pasteur Italia - Fondazione Cenci Bolognetti, Sapienza University of Rome, Latina, Italy
| | - John P Morrissey
- School of Microbiology, Centre for Synthetic Biology and Biotechnology, Environmental Research Institute, APC Microbiome Institute, University College Cork, Cork, Ireland
| | - Conor P O'Byrne
- Microbiology, School of Natural Sciences, College of Science, National University of Ireland, Galway, Ireland
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42
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Budnick JA, Sheehan LM, Benton AH, Pitzer JE, Kang L, Michalak P, Roop RM, Caswell CC. Characterizing the transport and utilization of the neurotransmitter GABA in the bacterial pathogen Brucella abortus. PLoS One 2020; 15:e0237371. [PMID: 32845904 PMCID: PMC7449393 DOI: 10.1371/journal.pone.0237371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2020] [Accepted: 08/04/2020] [Indexed: 01/18/2023] Open
Abstract
The neurotransmitter gamma-aminobutyric acid (GABA) is the most abundant inhibitory neurotransmitter in the human brain; however, it is becoming more evident that this non-proteinogenic amino acid plays multiple physiological roles in biology. In the present study, the transport and function of GABA is studied in the highly infectious intracellular bacterium Brucella abortus. The data show that 3H-GABA is imported by B. abortus under nutrient limiting conditions and that the small RNAs AbcR1 and AbcR2 negatively regulate this transport. A specific transport system, gts, is responsible for the transport of GABA as determined by measuring 3H-GABA transport in isogenic deletion strains of known AbcR1/2 regulatory targets; however, this locus is unnecessary for Brucella infection in BALB/c mice. Similar assays revealed that 3H-GABA transport is uninhibited by the 20 standard proteinogenic amino acids, representing preference for the transport of 3H-GABA. Metabolic studies did not show any potential metabolic utilization of GABA by B. abortus as a carbon or nitrogen source, and RNA sequencing analysis revealed limited transcriptional differences between B. abortus 2308 with or without exposure to GABA. While this study provides evidence for GABA transport by B. abortus, questions remain as to why and when this transport is utilized during Brucella pathogenesis.
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Affiliation(s)
- James A. Budnick
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, United States of America
- Center for One Health Research, Blacksburg, Virginia, United States of America
| | - Lauren M. Sheehan
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, United States of America
- Center for One Health Research, Blacksburg, Virginia, United States of America
| | - Angela H. Benton
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, United States of America
- Center for One Health Research, Blacksburg, Virginia, United States of America
| | - Joshua E. Pitzer
- Department of Microbiology and Immunology, East Carolina University Brody School of Medicine, Greenville, North Carolina, United States of America
| | - Lin Kang
- Center for One Health Research, Blacksburg, Virginia, United States of America
- Edward Via College of Osteopathic Medicine, Blacksburg, Virginia, United States of America
| | - Pawel Michalak
- Center for One Health Research, Blacksburg, Virginia, United States of America
- Edward Via College of Osteopathic Medicine, Blacksburg, Virginia, United States of America
- Institute of Evolution, University of Haifa, Haifa, Israel
| | - R. Martin Roop
- Department of Microbiology and Immunology, East Carolina University Brody School of Medicine, Greenville, North Carolina, United States of America
| | - Clayton C. Caswell
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Blacksburg, Virginia, United States of America
- Center for One Health Research, Blacksburg, Virginia, United States of America
- * E-mail:
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43
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Li H, Sun X, Liao X, Gänzle M. Control of pathogenic and spoilage bacteria in meat and meat products by high pressure: Challenges and future perspectives. Compr Rev Food Sci Food Saf 2020; 19:3476-3500. [PMID: 33337070 DOI: 10.1111/1541-4337.12617] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/10/2020] [Accepted: 07/19/2020] [Indexed: 01/18/2023]
Abstract
High-pressure processing is among the most widely used nonthermal intervention to reduce pathogenic and spoilage bacteria in meat and meat products. However, resistance of pathogenic bacteria strains in meats at the current maximum commercial equipment of 600 MPa questions the ability of inactivation by its application in meats. Pathogens including Escherichia coli, Listeria, and Salmonelle, and spoilage microbiota including lactic acid bacteria dominate in raw meat, ready-to-eat, and packaged meat products. Improved understanding on the mechanisms of the pressure resistance is needed for optimizing the conditions of pressure treatment to effectively decontaminate harmful bacteria. Effective control of the pressure-resistant pathogens and spoilage organisms in meats can be realized by the combination of high pressure with application of mild temperature and/or other hurdles including antimicrobial agents and/or competitive microbiota. This review summarized applications, mechanisms, and challenges of high pressure on meats from the perspective of microbiology, which are important for improving the understanding and optimizing the conditions of pressure treatment in the future.
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Affiliation(s)
- Hui Li
- Institute of Quality Standard and Testing Technology for Agro-Products, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaohong Sun
- College of Food and Biological Engineering, Qiqihar University, Qiqihar, Heilongjiang, China
| | - Xiaojun Liao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, China
| | - Michael Gänzle
- Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Canada
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44
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Ma X, Zhang S, Xu Z, Li H, Xiao Q, Qiu F, Zhang W, Long Y, Zheng D, Huang B, Chen C, Lu Y. SdiA Improves the Acid Tolerance of E. coli by Regulating GadW and GadY Expression. Front Microbiol 2020; 11:1078. [PMID: 32582066 PMCID: PMC7286202 DOI: 10.3389/fmicb.2020.01078] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 04/30/2020] [Indexed: 01/20/2023] Open
Abstract
The acid tolerance mechanism is important for Escherichia coli to resist acidic conditions encountered in mammalian host digestive tract environment. Here, we explored how the LuxR protein SdiA influenced E. coli acid tolerance ability in the context of the glutamate- and glutamine-dependent acid resistance system (AR2). First, using a growth and acid shock assay under different acid stresses, we demonstrated that the deletion of sdiA in SM10λpir or BW25113 led to impaired growth under the acidic environment of pH 3–6, which was restored by complementary expression of SdiA. Next, transcriptome sequencing and qPCR disclosed that the expression of glutamate decarboxylase W (GadW) and GadY, the key members of the AR2 system, were regulated by SdiA. Further, β-galactosidase reporter assays showed that the promoter activity of gadW and gadY was positively regulated by SdiA. Moreover, qPCR and β-galactosidase reporter assays confirmed that the regulation of SdiA on GadW, but not GadY, could be enhanced by quorum sensing (QS) signal molecules AHLs. Collectively, these data suggest that SdiA plays a crucial role in acid tolerance regulation of E. coli. Our findings provide new insights into the important contribution of quorum sensing system AHLs–SdiA to the networks that regulate acid tolerance.
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Affiliation(s)
- Xingyan Ma
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Shebin Zhang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhenjie Xu
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Honglin Li
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Qian Xiao
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Feng Qiu
- Department of Laboratory Medicine, Nanhai Hospital, Southern Medical University, Foshan, China
| | - Weizheng Zhang
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yifei Long
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Dexiang Zheng
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Bin Huang
- Department of Laboratory Medicine, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Cha Chen
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yang Lu
- Department of Laboratory Medicine, The Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.,The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou, China
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45
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Catlin DS, Reidl CT, Trzupek TR, Silverman RB, Cannon BL, Becker DP, Liu D. (S)-4-Amino-5-phenoxypentanoate designed as a potential selective agonist of the bacterial transcription factor GabR. Protein Sci 2020; 29:1816-1828. [PMID: 32557944 DOI: 10.1002/pro.3905] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/12/2020] [Accepted: 06/16/2020] [Indexed: 12/14/2022]
Abstract
Addressing molecular recognition in the context of evolution requires pursuing new molecular targets to enable the development of agonists or antagonists with new mechanisms of action. Disruption of transcriptional regulation through targeting transcription factors that regulate the expression of key enzymes in bacterial metabolism may provide a promising method for controlling the bacterial metabolic pathways. To this end, we have selectively targeted a bacterial transcription regulator through the design and synthesis of a series of γ-aminobutyric acid (GABA) derivatives, including (S)-4-amino-5-phenoxypentanoate (4-phenoxymethyl-GABA), which are based on docking insights gained from a previously-solved crystal structure of GabR from Bacillus subtilis. This target was selected because GabR strictly controls GABA metabolism by regulating the transcription of the gabT/D operon. These GabR transcription modulators are selective for the bacterial transcription factor GabR and are unable to bind to structural homologs of GabR due to distinct steric constraints. We have obtained a crystal structure of 4-phenoxymethyl-GABA bound as an external aldimine with PLP in the effector binding site of GabR, which suggests that this compound is capable of binding and reacting in the same manner as the native effector ligand. Inhibition assays demonstrate high selectivity of 4-phenoxymethyl-GABA for bacterial GabR versus several selected eukaryotic enzymes. Single-molecule fluorescence resonance energy transfer (smFRET) experiments reveal a ligand-induced DNA distortion that is very similar to that of the native effector GABA, suggesting that the compound functions as a potential selective agonist of GabR.
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Affiliation(s)
- Daniel S Catlin
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois, USA
| | - Cory T Reidl
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois, USA
| | - Thomas R Trzupek
- Department of Chemistry, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois, USA
| | - Richard B Silverman
- Department of Chemistry, Chemistry of Life Processes Institute, Center for Molecular Innovation and Drug Discovery, Northwestern University, Evanston, Illinois, USA.,Department of Molecular Biosciences, Northwestern University, Evanston, Illinois, USA
| | - Brian L Cannon
- Department of Physics, Loyola University Chicago, Chicago, Illinois, USA
| | - Daniel P Becker
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois, USA
| | - Dali Liu
- Department of Chemistry and Biochemistry, Loyola University Chicago, Chicago, Illinois, USA
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46
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Wang C, Ren X, Yu C, Wang J, Wang L, Zhuge X, Liu X. Physiological and Transcriptional Responses of Streptomyces albulus to Acid Stress in the Biosynthesis of ε-Poly-L-lysine. Front Microbiol 2020; 11:1379. [PMID: 32636829 PMCID: PMC7317143 DOI: 10.3389/fmicb.2020.01379] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 05/28/2020] [Indexed: 02/06/2023] Open
Abstract
Streptomyces albulus has commercially been used for the production of ε-poly-L-lysine (ε-PL), a natural food preservative, where acid stress is inevitably encountered in the biosynthesis process. To elucidate the acid tolerance response (ATR), a comparative physiology and transcriptomic analysis of S. albulus M-Z18 at different environmental pH (5.0, 4.0, and 3.0) was carried out. In response to acid stress, cell envelope regulated the membrane fatty acid composition and chain length to reduce damage. Moreover, intracellular pH homeostasis was maintained by increasing H+-ATPase activity and intracellular ATP and amino acid (mainly arginine, glutamate, aspartate and lysine) concentrations. Transcriptional analysis based on RNA-sequencing indicated that acid stress aroused global changes and the differentially expressed genes involved in transcriptional regulation, stress-response protein, transporter, cell envelope, secondary metabolite biosynthesis, DNA and RNA metabolism and ribosome subunit. Consequently, the ATR of S. albulus was preliminarily proposed. Notably, it is indicated that the biosynthesis of ε-PL is also a response mechanism for S. albulus to combat acid stress. These results provide new insights into the ATR of S. albulus and will contribute to the production of ε-PL via adaptive evolution or metabolic engineering.
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Affiliation(s)
- Chenying Wang
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Xidong Ren
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China.,Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Chao Yu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China.,Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Junming Wang
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China.,Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Li Wang
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China.,Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
| | - Xin Zhuge
- Process Development Department, IntellectiveBio Co., Ltd., Suzhou, China
| | - Xinli Liu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China.,Shandong Provincial Key Laboratory of Microbial Engineering, Department of Bioengineering, Qilu University of Technology, Shandong Academy of Sciences, Jinan, China
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Using hydrochloric acid and bile resistance for optimized detection and isolation of Shiga toxin-producing Escherichia coli (STEC) from sprouts. Int J Food Microbiol 2020; 322:108562. [PMID: 32109682 DOI: 10.1016/j.ijfoodmicro.2020.108562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/07/2020] [Accepted: 02/10/2020] [Indexed: 11/21/2022]
Abstract
Shiga toxin-producing Escherichia coli (STEC) in sprouts have caused large scale outbreaks in the past involving severe illness. The combination of this very diverse pathogen and a food matrix with high numbers of background microbiota poses a particular challenge for detection and isolation. An acid treatment of the enrichment before plating on agar has been shown to improve the recovery of STEC from sprouts. After enrichment in buffered peptone water (BPW) at 37 °C we applied an acid treatment, followed by plating on tryptone bile x-glucuronide (TBX) agar (acid bile method). An inter-laboratory study was organized with 21 laboratories taking part to evaluate the performance parameters and applicability of the acid bile method. A sample set of six sprout samples was prepared consisting of two uninoculated samples and four spiked samples, each containing one of two STEC strains at one of two concentrations (low and high). Analyzing a set of six samples at the National Reference Laboratory (NRL E. coli), we determined the relative abundance of STEC without, after acid-, after bile- and after acid-bile treatment using real-time PCR. The participating laboratories successfully applied the acid bile method and were better able to detect (sensitivity 92.9% vs. 70.0%) and isolate (sensitivity 87.5% vs. 31.3%) STEC from positive samples using the acid bile method compared to non-acid methods. The relative limit of detection (RLOD) after isolation using the acid bile method (vs. non-acid method) was <1 for both STEC strains used, BfR-EC-14434 O133:H25 (0.146) and BfR-EC-16015 O26:H11 (0.073). A collection of STEC (n = 71) of diverse type and characteristics was assessed for their resistance towards the acid bile treatment selection. The majority (n = 65) of STEC strains could be recovered after acid treatment on TBX plates. However, a few strains (n = 6), among them clinical isolates were (partly) sensitive. These results suggest that an acid bile method is a rapid and reasonable approach to improve the recovery of STEC from sprouts when used in combination with methods targeting other selection markers.
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Stefano GB, Esch T, Kream RM. Potential Immunoregulatory and Antiviral/SARS-CoV-2 Activities of Nitric Oxide. Med Sci Monit 2020; 26:e925679. [PMID: 32454510 PMCID: PMC7271680 DOI: 10.12659/msm.925679] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Nitric oxide (NO) represents a key signaling molecule in multiple regulatory pathways underlying vascular, metabolic, immune, and neurological function across animal phyla. Our brief critical discussion is focused on the multiple roles of the NO signaling pathways in the maintenance of basal physiological states of readiness in diverse cell types mediating innate immunological functions and in the facilitation of proinflammatory-mediated adaptive immunological responses associated with viral infections. Prior studies have reinforced the critical importance of constitutive NO signaling pathways in the homeostatic maintenance of the vascular endothelium, and state-dependent changes in innate immunological responses have been associated with a functional override of NO-mediated inhibitory tone. Accordingly, convergent lines of evidence suggest that dysregulation of NO signaling pathways, as well as canonical oxidative effects of inducible NO, may provide a permissive cellular environment for viral entry and replication. In immunologically compromised individuals, functional override and chronic rundown of inhibitory NO signaling systems promote aberrant expression of unregulated proinflammatory pathways resulting in widespread metabolic insufficiencies and structural damage to autonomous cellular and organ structures. We contend that restoration of normative NO tone via combined pharmaceutical, dietary, or complex behavioral interventions may partially reverse deleterious physiological conditions brought about by viral infection linked to unregulated adaptive immune responses.
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Affiliation(s)
- George B Stefano
- International Scientific Information, Inc., Melville, NY, USA.,Department of Psychiatry, First Faculty of Medicine Charles University in Prague and General University Hospital in Prague, Center for Cognitive and Molecular Neuroscience, Prague, Czech Republic
| | - Tobias Esch
- University Clinic for Integrative Health Care, Institute for Integrative Health Care and Health Promotion, Faculty of Health/School of Medicine, Witten/Herdecke University, Witten, Germany
| | - Richard M Kream
- Department of Psychiatry, First Faculty of Medicine Charles University in Prague and General University Hospital in Prague, Center for Cognitive and Molecular Neuroscience, Prague, Czech Republic
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Schwan WR, Flohr NL, Multerer AR, Starkey JC. GadE regulates fliC gene transcription and motility in Escherichia coli. World J Clin Infect Dis 2020; 10:14-23. [PMID: 32728533 PMCID: PMC7388676 DOI: 10.5495/wjcid.v10.i1.14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 03/25/2020] [Accepted: 05/05/2020] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Escherichia coli (E. coli) express flagella to ascend human urinary tracts. To survive in the acidic pH of human urine, E. coli uses the glutamate decarboxylase acid response system, which is regulated by the GadE protein.
AIM To determine if growth in an acidic pH environment affected fliC transcription and whether GadE regulated that transcription.
METHODS A fliC-lacZ reporter fusion was created on a single copy number plasmid to assess the effects of acidic pH on fliC transcription. Further, a ΔgadE mutant strain of a uropathogenic E. coli was created and tested for motility compared to the wild-type strain.
RESULTS Escherichia coli cells carrying the fliC-lacZ fusion displayed significantly less fliC transcription when grown in an acidic pH medium compared to when grown in a neutral pH medium. Transcription of fliC fell further when the E. coli was grown in an acidic pH/high osmolarity environment. Since GadE is a critical regulator of one acid response system, fliC transcription was tested in a gadE mutant strain grown under acidic conditions. Expression of fliC was derepressed in the E. coli gadE mutant strain grown under acidic conditions compared to that in wild-type bacteria under the same conditions. Furthermore, a gadE mutation in a uropathogenic E. coli background exhibited significantly greater motility than the wild-type strain following growth in an acidic medium.
CONCLUSION Together, our results suggest that GadE may down-regulate fliC transcription and motility in E. coli grown under acidic conditions.
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Affiliation(s)
- William R Schwan
- Department of Microbiology, University of Wisconsin-La Crosse, La Crosse, WI 54601, United States
| | - Nicole L Flohr
- Department of Microbiology, University of Wisconsin-La Crosse, La Crosse, WI 54601, United States
| | - Abigail R Multerer
- Department of Microbiology, University of Wisconsin-La Crosse, La Crosse, WI 54601, United States
| | - Jordan C Starkey
- Department of Microbiology, University of Wisconsin-La Crosse, La Crosse, WI 54601, United States
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