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Icer MA, Sarikaya B, Kocyigit E, Atabilen B, Çelik MN, Capasso R, Ağagündüz D, Budán F. Contributions of Gamma-Aminobutyric Acid (GABA) Produced by Lactic Acid Bacteria on Food Quality and Human Health: Current Applications and Future Prospects. Foods 2024; 13:2437. [PMID: 39123629 PMCID: PMC11311711 DOI: 10.3390/foods13152437] [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: 06/10/2024] [Revised: 07/20/2024] [Accepted: 07/29/2024] [Indexed: 08/12/2024] Open
Abstract
The need to increase food safety and improve human health has led to a worldwide increase in interest in gamma-aminobutyric acid (GABA), produced by lactic acid bacteria (LABs). GABA, produced from glutamic acid in a reaction catalyzed by glutamate decarboxylase (GAD), is a four-carbon, non-protein amino acid that is increasingly used in the food industry to improve the safety/quality of foods. In addition to the possible positive effects of GABA, called a postbiotic, on neuroprotection, improving sleep quality, alleviating depression and relieving pain, the various health benefits of GABA-enriched foods such as antidiabetic, antihypertension, and anti-inflammatory effects are also being investigated. For all these reasons, it is not surprising that efforts to identify LAB strains with a high GABA productivity and to increase GABA production from LABs through genetic engineering to increase GABA yield are accelerating. However, GABA's contributions to food safety/quality and human health have not yet been fully discussed in the literature. Therefore, this current review highlights the synthesis and food applications of GABA produced from LABs, discusses its health benefits such as, for example, alleviating drug withdrawal syndromes and regulating obesity and overeating. Still, other potential food and drug interactions (among others) remain unanswered questions to be elucidated in the future. Hence, this review paves the way toward further studies.
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Affiliation(s)
- Mehmet Arif Icer
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Amasya University, Amasya 05100, Turkey;
| | - Buse Sarikaya
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Amasya University, Amasya 05100, Turkey;
| | - Emine Kocyigit
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Ordu University, Ordu 52000, Turkey;
| | - Büşra Atabilen
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Karamanoğlu Mehmetbey University, Karaman 70100, Turkey;
| | - Menşure Nur Çelik
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Ondokuz Mayıs University, Samsun 55000, Turkey;
| | - Raffaele Capasso
- Department of Agricultural Sciences, University of Naples Federico II, 80055 Portici, Italy;
| | - Duygu Ağagündüz
- Department of Nutrition and Dietetics, Faculty of Health Sciences, Gazi University, Emek, Ankara 06490, Turkey;
| | - Ferenc Budán
- Institute of Physiology, Medical School, University of Pécs, H-7624 Pécs, Hungary
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Milon RB, Hu P, Zhang X, Hu X, Ren L. Recent advances in the biosynthesis and industrial biotechnology of Gamma-amino butyric acid. BIORESOUR BIOPROCESS 2024; 11:32. [PMID: 38647854 PMCID: PMC10992975 DOI: 10.1186/s40643-024-00747-7] [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: 12/15/2023] [Accepted: 03/03/2024] [Indexed: 04/25/2024] Open
Abstract
GABA (Gamma-aminobutyric acid), a crucial neurotransmitter in the central nervous system, has gained significant attention in recent years due to its extensive benefits for human health. The review focused on recent advances in the biosynthesis and production of GABA. To begin with, the investigation evaluates GABA-producing strains and metabolic pathways, focusing on microbial sources such as Lactic Acid Bacteria, Escherichia coli, and Corynebacterium glutamicum. The metabolic pathways of GABA are elaborated upon, including the GABA shunt and critical enzymes involved in its synthesis. Next, strategies to enhance microbial GABA production are discussed, including optimization of fermentation factors, different fermentation methods such as co-culture strategy and two-step fermentation, and modification of the GABA metabolic pathway. The review also explores methods for determining glutamate (Glu) and GABA levels, emphasizing the importance of accurate quantification. Furthermore, a comprehensive market analysis and prospects are provided, highlighting current trends, potential applications, and challenges in the GABA industry. Overall, this review serves as a valuable resource for researchers and industrialists working on GABA advancements, focusing on its efficient synthesis processes and various applications, and providing novel ideas and approaches to improve GABA yield and quality.
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Affiliation(s)
- Ripon Baroi Milon
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
| | - Pengchen Hu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
| | - Xueqiong Zhang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
| | - Xuechao Hu
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China
- Shanghai JanStar Technology Development Co, Ltd., No. 1288, Huateng Road, Shanghai, People's Republic of China
| | - Lujing Ren
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30 South Puzhu Road, Nanjing, 211816, People's Republic of China.
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Development of an oil-sealed anaerobic fermentation process for high production of γ-aminobutyric acid with Lactobacillus brevis isolated by directional colorimetric screening. Biochem Eng J 2023. [DOI: 10.1016/j.bej.2023.108893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
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4
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High level production of γ-aminobutyric acid in engineered Escherichia coli by refactoring the glutamate decarboxylase. Process Biochem 2022. [DOI: 10.1016/j.procbio.2022.04.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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5
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Abstract
The bacterial genus Lactobacillus comprises a vast range of strains with varying metabolic and probiotic traits, with genome editing representing an essential tool to probe genotype-phenotype relationships and enhance their beneficial properties. Currently, one of the most effective means of genome editing in bacteria couples low-efficiency recombineering with high-efficiency counterselection by nucleases from CRISPR-Cas systems. In lactobacilli, several CRISPR-based genome editing methods exist that have shown varying success in different strains. Here, we detail a fast and simple approach using two shuttle vectors encoding a recombineering template as well as the Streptococcus pyogenes Cas9, a trans-activating RNA, and a CRISPR array. We provide a step-by-step procedure for cloning the shuttle vectors, sequentially transforming the vectors into lactobacilli, screening for the desired edit, and finally clearing the shuttle vectors from the mutant strain. As CRISPR-based genome editing in bacteria can fail for various reasons, we also lay out instructions for probing mechanisms of escape. Finally, we include practical notes along the way to facilitate each stage of genome editing, and we illustrate the technique using a representative edit in a strain of Lactobacillus plantarum. Overall, this method should serve as a complete guide to performing genome editing in lactobacilli.
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Affiliation(s)
- Justin M Vento
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA
| | - Chase L Beisel
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, NC, USA.
- Helmholtz Institute for RNA-based Infection Research (HIRI), Helmholtz-Centre for Infection Research (HZI), Würzburg, Germany.
- Medical Faculty, University of Würzburg, Würzburg, Germany.
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An Overview of Bioprocesses Employing Specifically Selected Microbial Catalysts for γ-Aminobutyric Acid Production. Microorganisms 2021; 9:microorganisms9122457. [PMID: 34946060 PMCID: PMC8704203 DOI: 10.3390/microorganisms9122457] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 11/17/2022] Open
Abstract
Gamma-aminobutyric acid (GABA) is an important chemical compound in the human brain. GABA acts as an inhibitory neurotransmitter by inducing hyperpolarization of cellular membranes. Usually, this pharmaceutically important compound is synthesized using a chemical process, but in this short overview we have only analysed microbial processes, which have been studied for the biosynthesis of this commercially important compound. The content of this article includes the following summarised information: the search for biological processes showed a number of lactic acid bacteria and certain species of fungi, which could be effectively used for the production of GABA. Strains found to possess GABA-producing pathways include Lactobacillus brevis CRL 1942, L. plantarum FNCC 260, Streptococcus salivarius subsp. thermophilus Y2, Bifidobacterium strains, Monascus spp., and Rhizopus spp. Each of these strains required specific growth conditions. However, several factors were common among these strains, such as the use of two main supplements in their fermentation medium—monosodium glutamate and pyridoxal phosphate—and maintaining an acidic pH. Optimization studies of GABA production were comprised of altering the media constituents, modifying growth conditions, types of cultivation system, and genetic manipulation. Some strains increased the production of GABA under anaerobic conditions. Genetic manipulation focused on silencing some genes or overexpression of gadB and gadC. The conclusion, based on the review of information available in published research, is that the targeted manipulation of selected microorganisms, as well as the culture conditions for an optimised bioprocess, should be adopted for an increased production of GABA to meet its increasing demand for food and pharmaceutical applications.
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Su A, Yu Q, Luo Y, Yang J, Wang E, Yuan H. Metabolic engineering of microorganisms for the production of multifunctional non-protein amino acids: γ-aminobutyric acid and δ-aminolevulinic acid. Microb Biotechnol 2021; 14:2279-2290. [PMID: 33675575 PMCID: PMC8601173 DOI: 10.1111/1751-7915.13783] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 02/09/2021] [Accepted: 02/12/2021] [Indexed: 12/14/2022] Open
Abstract
Gamma-aminobutyric acid (GABA) and delta-aminolevulinic acid (ALA), playing important roles in agriculture, medicine and other fields, are multifunctional non-protein amino acids with similar and comparable properties and biosynthesis pathways. Recently, microbial synthesis has become an inevitable trend to produce GABA and ALA due to its green and sustainable characteristics. In addition, the development of metabolic engineering and synthetic biology has continuously accelerated and increased the GABA and ALA yield in microorganisms. Here, focusing on the current trends in metabolic engineering strategies for microbial synthesis of GABA and ALA, we analysed and compared the efficiency of various metabolic strategies in detail. Moreover, we provide the insights to meet challenges of realizing industrially competitive strains and highlight the future perspectives of GABA and ALA production.
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Affiliation(s)
- Anping Su
- State Key Laboratory of Agrobiotechnology and Key Laboratory of Soil MicrobiologyMinistry of AgricultureCollege of Biological SciencesChina Agricultural UniversityNo.2 Yuanmingyuan West RoadHaidian DistrictBeijing100193China
| | - Qijun Yu
- State Key Laboratory of Agrobiotechnology and Key Laboratory of Soil MicrobiologyMinistry of AgricultureCollege of Biological SciencesChina Agricultural UniversityNo.2 Yuanmingyuan West RoadHaidian DistrictBeijing100193China
| | - Ying Luo
- State Key Laboratory of Agrobiotechnology and Key Laboratory of Soil MicrobiologyMinistry of AgricultureCollege of Biological SciencesChina Agricultural UniversityNo.2 Yuanmingyuan West RoadHaidian DistrictBeijing100193China
| | - Jinshui Yang
- State Key Laboratory of Agrobiotechnology and Key Laboratory of Soil MicrobiologyMinistry of AgricultureCollege of Biological SciencesChina Agricultural UniversityNo.2 Yuanmingyuan West RoadHaidian DistrictBeijing100193China
| | - Entao Wang
- Departamento de MicrobiologíaEscuela Nacional de Ciencias BiológicasInstituto Politécnico NacionalMexico City11340Mexico
| | - Hongli Yuan
- State Key Laboratory of Agrobiotechnology and Key Laboratory of Soil MicrobiologyMinistry of AgricultureCollege of Biological SciencesChina Agricultural UniversityNo.2 Yuanmingyuan West RoadHaidian DistrictBeijing100193China
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Surachat K, Deachamag P, Kantachote D, Wonglapsuwan M, Jeenkeawpiam K, Chukamnerd A. In silico comparative genomics analysis of Lactiplantibacillus plantarum DW12, a potential gamma-aminobutyric acid (GABA)-producing strain. Microbiol Res 2021; 251:126833. [PMID: 34352473 DOI: 10.1016/j.micres.2021.126833] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/21/2021] [Accepted: 07/26/2021] [Indexed: 01/22/2023]
Abstract
Gamma-aminobutyric acid (GABA) is an amino that plays a major role as a neurotransmitter. It iscommonly produced by lactic acid bacteria (LAB) naturally found in fermented food and fruit. Lactiplantibacillus plantarum DW12 is a high potential GABA-producing strain isolated from a fermented beverage. In this study, to highlight its ability to produce GABA, we sequenced the genome of L. plantarum DW12 and then performed comprehensive bioinformatics and meta-analysis to compare the genomic data of previously published genomes. Also, the evolutionary analysis among L. plantarum species was demonstrated using pan-genome analysis against 576 genomes from the database. As a result, the DW12 genome comprises one circular chromosome of 3,217,574 bp. It contains several genes that encode for the production of antimicrobial compounds including plantaricin A, E, F, J, K, and N. The glutamic acid decarboxylase (GAD) operon was found in the DW12 genome, suggests a high potential of producing GABA in this strain. Therefore, L. plantarum DW12 could be a good candidate as a starter culture in the beverage and food industries due to its safety aspects and ability to produce GABA.
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Affiliation(s)
- Komwit Surachat
- Division of Computational Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand; Molecular Evolution and Computational Biology Research Unit, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
| | - Panchalika Deachamag
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
| | - Duangporn Kantachote
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
| | - Monwadee Wonglapsuwan
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
| | - Kongpop Jeenkeawpiam
- Division of Computational Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand; Molecular Evolution and Computational Biology Research Unit, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
| | - Arnon Chukamnerd
- Department of Biomedical Sciences, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
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Food-grade γ-aminobutyric acid production by immobilized glutamate decarboxylase from Lactobacillus plantarum in rice vinegar and monosodium glutamate system. Biotechnol Lett 2021; 43:2027-2034. [PMID: 34308525 DOI: 10.1007/s10529-021-03164-4] [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] [Received: 03/16/2021] [Accepted: 07/13/2021] [Indexed: 10/20/2022]
Abstract
OBJECTIVES γ-amino butyric acid (GABA) is a non-protein amino acid, considered a potent bioactive compound. This study focused on biosynthesis of food-grade GABA by immobilized glutamate decarboxylase (GAD) from Lactobacillus plantarum in the rice vinegar and monosodium glutamate (MSG) reaction system. RESULTS The gene encoding glutamate decarboxylase (GadB) from L. plantarum has been heterologously expressed in Lactococcus lactis and biochemically characterized. Recombinant GadB existed as a homodimer, and displayed maximal activity at 40 °C and pH 5.0. The Km value and catalytic efficiency (kcat/Km) of GadB for L-Glu was 22.33 mM and 62.4 mM-1 min-1, respectively, with a specific activity of 24.97 U/mg protein. Then, purified GadB was encapsulated in gellan gum beads. Compared to the free enzyme, immobilized GadB showed higher operational and storage stability. Finally, 9.82 to 21.48 g/L of GABA have been acquired by regulating the amounts of catalyst microspheres ranging from 0.5 to 0.8 g (wet weight) in 0.8 mL of the designed rice vinegar and MSG reaction system. CONCLUSIONS The method of production GABA by immobilized GadB microspheres mixed in the rice vinegar and MSG reaction system is introduced herein for the first time. Especially, the results obtained here meet the increased interest in the harnessing of biocatalyst to synthesize food-grade GABA.
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Reconstruction of the glutamate decarboxylase system in Lactococcus lactis for biosynthesis of food-grade γ-aminobutyric acid. Appl Microbiol Biotechnol 2021; 105:4127-4140. [PMID: 33990858 DOI: 10.1007/s00253-021-11328-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 04/24/2021] [Accepted: 04/29/2021] [Indexed: 10/21/2022]
Abstract
Gamma-aminobutyric acid (GABA), an important bioactive compound, is synthesized through the decarboxylation of L-glutamate (L-Glu) by glutamate decarboxylase (GAD). The use of lactic acid bacteria (LAB) as catalysts opens interesting avenues for the biosynthesis of food-grade GABA. However, a key obstacle involved in the improvement of GABA production is how to resolve the discrepancy of optimal pH between the intracellular GAD activity and cell growth. In this work, a potential GAD candidate (LpGadB) from Lactobacillus plantarum was heterologously expressed in Escherichia coli. Recombinant LpGadB existed as a homodimer under the native conditions with a molecular mass of 109.6 kDa and exhibited maximal activity at 40°C and pH 5.0. The Km value and catalytic efficiency (kcat/Km) of LpGadB for L-Glu was 21.33 mM and 1.19 mM-1s-1, respectively, with the specific activity of 26.67 μM/min/mg protein. Subsequently, four C-terminally truncated LpGadB mutants (GadBΔC10, GadBΔC11, GadBΔC12, GadBΔC13) were constructed based on homology modeling. Among them, the mutant GadBΔC11 with highest catalytic activity at near-neutral pH values was selected. In further, the GadBΔC11 and Glu/GABA antiporter (GadC) of Lactococcus lactis were co-overexpressed in the host L. lactis NZ3900. Finally, after 48 h of batch fermentation, the engineered strain L. lactis NZ3900/pNZ8149-gadBΔC11C yielded GABA concentration up to 33.52 g/L by applying a two-stage pH control strategy. Remarkably, this is the highest yield obtained to date for GABA from fermentation with L. lactis as a microbial cell factory.Key points• The GadB from L. plantarum was heterologously expressed in E. coli and biochemically characterized.• Deletion of the C-plug in GadB shifted its pH-dependent activity toward a higher pH.• Reconstructing the GAD system of L. lactis is an effective approach for improving its GABA production.
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Luo H, Liu Z, Xie F, Bilal M, Liu L, Yang R, Wang Z. Microbial production of gamma-aminobutyric acid: applications, state-of-the-art achievements, and future perspectives. Crit Rev Biotechnol 2021; 41:491-512. [PMID: 33541153 DOI: 10.1080/07388551.2020.1869688] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Gamma-aminobutyric acid (GABA) is an important non-protein amino acid with wide-ranging applications. Currently, GABA can be produced by a variety of methods, including chemical synthesis, plant enrichment, enzymatic methods, and microbial production. Among these methods, microbial production has gained increasing attention to meet the strict requirements of an additive in the fields of food, pharmaceutical, and livestock. In addition, renewable and abundant resources, such as glucose and lignocellulosic biomass can also be used for GABA microbial production under mild and environmentally friendly processing conditions. In this review, the applications, metabolic pathways and physiological functions of GABA in different microorganisms were firstly discussed. A comprehensive overview of the current status of process engineering strategies for enhanced GABA production, including fermentation optimization and whole-cell conversion from different feedstocks by various host strains is also provided. We also presented the state-of-the-art achievements in strain development strategies for industrial lactic acid bacteria (LAB), Corynebacterium glutamicum and Escherichia coli to enhance the performance of GABA bioproduction. In order to use bio-based GABA in the fields of food and pharmaceutical, some Generally Recognized as Safe (GRAS) strains such as LAB and C. glutamicum will be the promising chassis hosts. Toward the end of this review, current challenges and valuable research directions/strategies on the improvements of process and strain engineering for economic microbial production of GABA are also suggested.
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Affiliation(s)
- Hongzhen Luo
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Zheng Liu
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Fang Xie
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Muhammad Bilal
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Lina Liu
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Rongling Yang
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
| | - Zhaoyu Wang
- School of Life Science and Food Engineering, Huaiyin Institute of Technology, Huaian, China
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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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GlnR Negatively Regulates Glutamate-Dependent Acid Resistance in Lactobacillus brevis. Appl Environ Microbiol 2020; 86:AEM.02615-19. [PMID: 31953336 DOI: 10.1128/aem.02615-19] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 01/08/2020] [Indexed: 11/20/2022] Open
Abstract
Lactic acid bacteria often encounter a variety of multiple stresses in their natural and industrial fermentation environments. The glutamate decarboxylase (GAD) system is one of the most important acid resistance systems in lactic acid bacteria. In this study, we demonstrated that GlnR, a nitrogen regulator in Gram-positive bacteria, directly modulated γ-aminobutyric acid (GABA) conversion from glutamate and was involved in glutamate-dependent acid resistance in Lactobacillus brevis The glnR deletion strain (ΔglnR mutant) achieved a titer of 284.7 g/liter GABA, which is 9.8-fold higher than that of the wild-type strain. The cell survival of the glnR deletion strain was significantly higher than that of the wild-type strain under the condition of acid challenge and was positively correlated with initial glutamate concentration and GABA production. Quantitative reverse transcription-PCR assays demonstrated that GlnR inhibited the transcription of the glutamate decarboxylase-encoding gene (gadB), glutamate/GABA antiporter-encoding gene (gadC), glutamine synthetase-encoding gene (glnA), and specific transcriptional regulator-encoding gene (gadR) involved in gadCB operon regulation. Moreover, GABA production and glutamate-dependent acid resistance were absolutely abolished in the gadR glnR deletion strain. Electrophoretic mobility shift and DNase I footprinting assays revealed that GlnR directly bound to the 5'-untranslated regions of the gadR gene and gadCB operon, thus inhibiting their transcription. These results revealed a novel regulatory mechanism of GlnR on glutamate-dependent acid resistance in Lactobacillus IMPORTANCE Free-living lactic acid bacteria often encounter acid stresses because of their organic acid-producing features. Several acid resistance mechanisms, such as the glutamate decarboxylase system, F1Fo-ATPase proton pump, and alkali production, are usually employed to relieve growth inhibition caused by acids. The glutamate decarboxylase system is vital for GAD-containing lactic acid bacteria to protect cells from DNA damage, enzyme inactivation, and product yield loss in acidic habitats. In this study, we found that a MerR-type regulator, GlnR, was involved in glutamate-dependent acid resistance by directly regulating the transcription of the gadR gene and gadCB operon, resulting in an inhibition of GABA conversion from glutamate in L. brevis This study represents a novel mechanism for GlnR's regulation of glutamate-dependent acid resistance and also provides a simple and novel strategy to engineer Lactobacillus strains to elevate their acid resistance as well as GABA conversion from glutamate.
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Improving the Thermostability of Glutamate Decarboxylase from Lactobacillus brevis by Consensus Mutagenesis. Appl Biochem Biotechnol 2020; 191:1456-1469. [DOI: 10.1007/s12010-020-03283-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 02/13/2020] [Indexed: 01/22/2023]
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16
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Cui Y, Miao K, Niyaphorn S, Qu X. Production of Gamma-Aminobutyric Acid from Lactic Acid Bacteria: A Systematic Review. Int J Mol Sci 2020; 21:ijms21030995. [PMID: 32028587 PMCID: PMC7037312 DOI: 10.3390/ijms21030995] [Citation(s) in RCA: 176] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 01/21/2020] [Accepted: 01/27/2020] [Indexed: 02/04/2023] Open
Abstract
Gamma-aminobutyric acid (GABA) is widely distributed in nature and considered a potent bioactive compound with numerous and important physiological functions, such as anti-hypertensive and antidepressant activities. There is an ever-growing demand for GABA production in recent years. Lactic acid bacteria (LAB) are one of the most important GABA producers because of their food-grade nature and potential of producing GABA-rich functional foods directly. In this paper, the GABA-producing LAB species, the biosynthesis pathway of GABA by LAB, and the research progress of glutamate decarboxylase (GAD), the key enzyme of GABA biosynthesis, were reviewed. Furthermore, GABA production enhancement strategies are reviewed, from optimization of culture conditions and genetic engineering to physiology-oriented engineering approaches and co-culture methods. The advances in both the molecular mechanisms of GABA biosynthesis and the technologies of synthetic biology and genetic engineering will promote GABA production of LAB to meet people’s demand for GABA. The aim of the review is to provide an insight of microbial engineering for improved production of GABA by LAB in the future.
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Affiliation(s)
- Yanhua Cui
- Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150090, China; (K.M.)
- Correspondence:
| | - Kai Miao
- Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150090, China; (K.M.)
| | - Siripitakyotin Niyaphorn
- Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150090, China; (K.M.)
| | - Xiaojun Qu
- Institute of Microbiology, Heilongjiang Academy of Sciences, Harbin 150010, China;
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17
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Lyu CJ, Liu L, Huang J, Zhao WR, Hu S, Mei LH, Yao SJ. Biosynthesis of γ-aminobutyrate by engineered Lactobacillus brevis cells immobilized in gellan gum gel beads. J Biosci Bioeng 2019; 128:123-128. [DOI: 10.1016/j.jbiosc.2019.01.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 01/03/2019] [Accepted: 01/17/2019] [Indexed: 01/07/2023]
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18
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Gong L, Ren C, Xu Y. Deciphering the crucial roles of transcriptional regulator GadR on gamma-aminobutyric acid production and acid resistance in Lactobacillus brevis. Microb Cell Fact 2019; 18:108. [PMID: 31196094 PMCID: PMC6567505 DOI: 10.1186/s12934-019-1157-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 06/07/2019] [Indexed: 11/26/2022] Open
Abstract
Background In lactic acid bacteria (LAB), acid stress leads to decreases of cell vitality and fermentation yield. Glutamate decarboxylase (GAD) system is regarded as one of the essential acid-resistance mechanisms in LAB. However, the regulation of GAD system is not well identified in the genus Lactobacillus. Although potential transcriptional regulator gene located upstream of GAD system genes was found in several Lactobacillus species, such as Lactobacillus (L.) brevis, the contribution of the regulator to acid resistance of the genus Lactobacillus has not been experimentally determined. Results The potential transcriptional regulator gene gadR was disrupted by homologous recombination in L. brevis ATCC 367, leading to the decreased expression of gadC and gadB. The inactivation of GadR completely eliminated γ-aminobutyric acid (GABA) production and decreased the glutamate-dependent acid resistance. Moreover, expression of gadC and gadB in the presence of glutamate was increased and glutamate also stimulated the expression of gadR. In addition, L. brevis D17, a strain screened from acidic fermented grains of Chinese liquor production, had much higher expression level of gadR than the typical strain L. brevis ATCC 367. Under the pH-controlled and mixed-feed fermentation, L. brevis D17 achieved a titer of 177.74 g/L and a productivity of 4.94 g/L/h of GABA within 36 h. However, the L. brevis ATCC 367 only achieved a titer of 6.44 g/L and 0.18 g/L/h of GABA although the same fermentation control approach was employed. Conclusions GadR is a positive transcriptional regulator controlling GABA conversion and acid resistance in L. brevis. L. brevis strains with hyper-expressing of gadR are excellent candidates for GABA production in industrial scale. Electronic supplementary material The online version of this article (10.1186/s12934-019-1157-2) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Luchan Gong
- Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Cong Ren
- Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi, 214122, China
| | - Yan Xu
- Key Laboratory of Industrial Biotechnology of Ministry of Education, State Key Laboratory of Food Science and Technology, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
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19
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Gao D, Chang K, Ding G, Wu H, Chen Y, Jia M, Liu X, Wang S, Jin Y, Pan H, Li H. Genomic insights into a robust gamma-aminobutyric acid-producer Lactobacillus brevis CD0817. AMB Express 2019; 9:72. [PMID: 31127390 PMCID: PMC6534642 DOI: 10.1186/s13568-019-0799-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 05/16/2019] [Indexed: 01/22/2023] Open
Abstract
Lactobacillus brevis CD0817, a strain isolated from a healthy adult gut, was currently the most efficient lactic acid bacterial cell factory for gamma-aminobutyric acid. In this study, the complete genome sequence of CD0817 was determined and compared with some related L. brevis genomes. The CD0817 genome consists of one 2,990,570-bp chromosome and four plasmids. The comparative genomic and phylogenetic analysis revealed that L. brevis CD0817 was not very conserved with low GABA-producing L. brevis strains. A significant divergence was that CD0817 harbors only the gadCA operon whereas the low GABA-producing L. brevis strains contain the operon and gadB. The gadB seemed to only marginally contribute to the accumulation of GABA. The high GABA production ability of CD0817 may be associated with its extraordinary genome.
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20
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Lyu C, Zhao W, Peng C, Hu S, Fang H, Hua Y, Yao S, Huang J, Mei L. Exploring the contributions of two glutamate decarboxylase isozymes in Lactobacillus brevis to acid resistance and γ-aminobutyric acid production. Microb Cell Fact 2018; 17:180. [PMID: 30454056 PMCID: PMC6240960 DOI: 10.1186/s12934-018-1029-1] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 11/12/2018] [Indexed: 01/26/2023] Open
Abstract
Background The glutamate decarboxylase (GAD) system of Lactobacillus brevis involves two isoforms of GAD, GadA and GadB, which catalyze the conversion of L-glutamate to γ-aminobutyric acid (GABA) in a proton-consuming reaction contributing to intracellular pH homeostasis. However, direct experimental evidence for detailed contributions of gad genes to acid tolerance and GABA production is lacking. Results Molecular analysis revealed that gadB is cotranscribed in tandem with upstream gadC, and that expression of gadCB is greatly upregulated in response to low ambient pH when cells enter the late exponential growth phase. In contrast, gadA is located away from the other gad genes, and its expression was consistently lower and not induced by mild acid treatment. Analysis of deletion mutations in the gad genes of L. brevis demonstrated a decrease in the level of GAD activity and a concomitant decrease in acid resistance in the order of wild-type> ΔgadA> ΔgadB> ΔgadC> ΔgadAB, indicating that the GAD activity mainly endowed by GadB rather than GadA is an indispensable step in the GadCB mediated acid resistance of this organism. Moreover, engineered strains with higher GAD activities were constructed by overexpressing key GAD system genes. With the proposed two-stage pH and temperature control fed-batch fermentation strategy, GABA production by the engineered strain L. brevis 9530: pNZ8148-gadBC continuously increased reaching a high level of 104.38 ± 3.47 g/L at 72 h. Conclusions This is the first report of the detailed contribution of gad genes to acid tolerance and GABA production in L. brevis. Enhanced production of GABA by engineered L. brevis was achieved, and the resulting GABA level was one of the highest among lactic acid bacterial species grown in batch or fed-batch culture. Electronic supplementary material The online version of this article (10.1186/s12934-018-1029-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Changjiang Lyu
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, China.,College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Weirui Zhao
- School of Biotechnology and Chemical Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo, 315100, China
| | - Chunlong Peng
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Sheng Hu
- School of Biotechnology and Chemical Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo, 315100, China
| | - Hui Fang
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, China
| | - Yujiao Hua
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, China
| | - Shanjing Yao
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Jun Huang
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, China.
| | - Lehe Mei
- College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, China. .,School of Biotechnology and Chemical Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo, 315100, China.
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21
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Huang J, Fang H, Gai ZC, Mei JQ, Li JN, Hu S, Lv CJ, Zhao WR, Mei LH. Lactobacillus brevis CGMCC 1306 glutamate decarboxylase: Crystal structure and functional analysis. Biochem Biophys Res Commun 2018; 503:1703-1709. [PMID: 30049439 DOI: 10.1016/j.bbrc.2018.07.102] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 07/20/2018] [Indexed: 01/14/2023]
Abstract
Glutamate decarboxylase (GAD), which is a unique pyridoxal 5-phosphate (PLP)-dependent enzyme, can catalyze α-decarboxylation of l-glutamate (L-Glu) to γ-aminobutyrate (GABA). The crystal structure of GAD in complex with PLP from Lactobacillus brevis CGMCC 1306 was successfully solved by molecular-replacement, and refined at 2.2 Å resolution to an Rwork factor of 18.76% (Rfree = 23.08%). The coenzyme pyridoxal 5-phosphate (PLP) forms a Schiff base with the active-site residue Lys279 by continuous electron density map, which is critical for catalysis by PLP-dependent decarboxylase. Gel filtration showed that the active (pH 4.8) and inactive (pH 7.0) forms of GAD are all dimer. The residues (Ser126, Ser127, Cys168, Ile211, Ser276, His278 and Ser321) play important roles in anchoring PLP cofactor inside the active site and supporting its catalytic reactivity. The mutant T215A around the putative substrate pocket displayed an 1.6-fold improvement in catalytic efficiency (kcat/Km) compared to the wild-type enzyme (1.227 mM-1 S-1 versus 0.777 mM-1 S-1), which was the highest activity among all variants tested. The flexible loop (Tyr308-Glu312), which is positioned near the substrate-binding site, is involved in the catalytic reaction, and the conserved residue Tyr308 plays a vital role in decarboxylation of L-Glu.
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Affiliation(s)
- Jun Huang
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, PR China; Department of Biological and Pharmaceutical Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo, 315100, PR China
| | - Hui Fang
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, PR China
| | - Zhong-Chao Gai
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, PR China
| | - Jia-Qi Mei
- Department of Chemical Engineering, The University of Utah, Salt Lake City, 84102, Utah, United States
| | - Jia-Nan Li
- College of Pharmacy, Zhejiang University of Technology, Hangzhou, 310014, PR China
| | - Sheng Hu
- Department of Biological and Pharmaceutical Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo, 315100, PR China
| | - Chang-Jiang Lv
- School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, PR China
| | - Wei-Rui Zhao
- Department of Biological and Pharmaceutical Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo, 315100, PR China
| | - Le-He Mei
- Department of Biological and Pharmaceutical Engineering, Ningbo Institute of Technology, Zhejiang University, Ningbo, 315100, PR China.
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