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Bryukhanov AL, Klimko AI, Netrusov AI. Antioxidant Properties of Lactic Acid Bacteria. Microbiology (Reading) 2022. [DOI: 10.1134/s0026261722601439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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2
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Zhang C, Han Y, Gui Y, Wa Y, Chen D, Huang Y, Yin B, Gu R. Influence of nitrogen sources on the tolerance of Lacticaseibacillus rhamnosus to heat stress and oxidative stress. J Ind Microbiol Biotechnol 2022; 49:6693999. [PMID: 36073749 PMCID: PMC9559300 DOI: 10.1093/jimb/kuac020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 09/02/2022] [Indexed: 11/14/2022]
Abstract
It has been found that 32 genes related to nitrogen source metabolism in Lacticaseibacillus rhamnosus are downregulated under both heat stress and oxidative stress. In this study, the influence of different nitrogen sources within the growth medium on the tolerance of L. rhamnosus to heat stress and oxidative stress was investigated. Tryptone-free MRS was found to enhance the tolerance of L. rhamnosus hsryfm 1301 to heat stress and oxidative stress during the whole growth period, and this result was universal for all L. rhamnosus species analyzed. The strongest strengthening effect occurred when the OD600 value reached 2.0, at which the survival rates under heat stress and oxidative stress increased 130-fold and 40-fold, respectively. After supplementing phenylalanine, isoleucine, glutamate, valine, histidine, or tryptophan into the tryptone-free MRS, the tolerance of L. rhamnosus to heat stress and oxidative stress exhibited a sharp drop. The spray drying survival rate of L. rhamnosus hsryfm 1301 cultured in the tryptone-free MRS rose to 75% (from 30%), and the spray dried powder also performed better in the experimentally simulated gastrointestinal digestion. These results showed that decreasing the intake of amino acids is an important mechanism for L. rhamnosus to tolerate heat stress and oxidative stress. When L. rhamnosus is cultured for spray drying, the concentration of the nitrogen source's components should be an important consideration.
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Affiliation(s)
- Chenchen Zhang
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China.,Jiangsu Dairy Biotechnology Engineering Research Center, Kang Yuan Dairy Co. Ltd., Yangzhou University, Yangzhou, P.R. China.,College of Bioscience and Biotechnology, Yangzhou University, Yangzhou, P.R. China
| | - Yuemei Han
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
| | - Ya Gui
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
| | - Yunchao Wa
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
| | - Dawei Chen
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
| | - Yujun Huang
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
| | - Boxing Yin
- Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China.,Jiangsu Dairy Biotechnology Engineering Research Center, Kang Yuan Dairy Co. Ltd., Yangzhou University, Yangzhou, P.R. China
| | - Ruixia Gu
- College of Food Science and Engineering, Yangzhou University, Yangzhou, P.R. China.,Jiangsu Key Laboratory of Dairy Biotechnology and Safety Control, Yangzhou, P.R. China
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Ye Q, Lee C, Shin E, Lee SJ. Influence of Redox Imbalances on the Transposition of Insertion Sequences in Deinococcus geothermalis. Antioxidants (Basel) 2021; 10:antiox10101623. [PMID: 34679757 PMCID: PMC8533066 DOI: 10.3390/antiox10101623] [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: 08/17/2021] [Revised: 10/11/2021] [Accepted: 10/13/2021] [Indexed: 01/11/2023] Open
Abstract
The transposition of insertion sequence elements was evaluated among different Deinococcus geothermalis lineages, including the wild-type, a cystine importer-disrupted mutant, a complemented strain, and a cystine importer-overexpressed strain. Cellular growth reached early exponential growth at OD600 2.0 and late exponential growth at OD600 4.0. Exposing the cells to hydrogen peroxide (80–100 mM) resulted in the transposition of insertion sequences (ISs) in genes associated with the carotenoid biosynthesis pathway. Particularly, ISDge7 (an IS5 family member) and ISDge5 (an IS701 family member) from the cystine importer-disrupted mutant were transposed into phytoene desaturase (dgeo_0524) via replicative transposition. Further, the cystine importer-overexpressed strain Δdgeo_1985R showed transposition of both ISDge2 and ISDge5 elements. In contrast, IS transposition was not detected in the complementary strain. Interestingly, a cystine importer-overexpressing strain exhibited streptomycin resistance, indicating that point mutation occurred in the rpsL (dgeo_1873) gene encoding ribosomal protein S12. qRT-PCR analyses were then conducted to evaluate the expression of oxidative stress response genes, IS elements, and low-molecular-weight thiol compounds such as mycothiol and bacillithiol. Nevertheless, the mechanisms that trigger IS transposition in redox imbalance conditions remain unclear. Here, we report that the active transposition of different IS elements was affected by intracellular redox imbalances caused by cystine importer deficiencies or overexpression.
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Xie J, Gänzle MG. Characterization of γ-glutamyl cysteine ligases from Limosilactobacillus reuteri producing kokumi-active γ-glutamyl dipeptides. Appl Microbiol Biotechnol 2021; 105:5503-5515. [PMID: 34228184 DOI: 10.1007/s00253-021-11429-1] [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: 04/20/2021] [Revised: 06/21/2021] [Accepted: 06/24/2021] [Indexed: 11/25/2022]
Abstract
γ-Glutamyl cysteine ligases (Gcls) catalyze the first step of glutathione synthesis in prokaryotes and many eukaryotes. This study aimed to determine the biochemical properties of three different Gcls from strains of Limosilactobacillus reuteri that accumulate γ-glutamyl dipeptides. Gcl1, Gcl2, and Gcl3 were heterologously expressed in Escherichia coli and purified by affinity chromatography. Gcl1, Gcl2, and Gcl2 exhibited biochemical with respect to the requirement for metal ions, the optimum pH and temperature of activity, and the kinetic constants for the substrates cysteine and glutamate. The substrate specificities of the three Gcls to 14 amino acids were assessed by liquid chromatography-mass spectrometry. All three Gcls converted ala, met, glu, and gln into the corresponding γ-glutamyl dipeptides. None of the three were active with val, asp, and his. Gcl1 and Gcl3 but not Gcl2 formed γ-glu-leu, γ-glu-ile, and γ-glu-phe; Gcl3 exhibited stronger activity with gly, pro, and asp when compared to Gcl2. Phylogenetic analysis of Gcl and the Gcl-domain of GshAB in lactobacilli demonstrated that most of Gcls were present in heterofermentative lactobacilli, while GshAB was identified predominantly in homofermentative lactobacilli. This distribution suggests a different ecological role of the enzyme in homofermentative and heterofermentative lactobacilli. In conclusion, three Gcls exhibited similar biochemical properties but differed with respect to their substrate specificity and thus the synthesis of kokumi-active γ-glutamyl dipeptides. KEY POINTS: • Strains of Limosilactobacillus reuteri encode for up to 3 glutamyl cysteine ligases. • Gcl1, Gcl2, and Gcl3 of Lm. reuteri differ in their substrate specificity. • Gcl1 and Gcl3 produce kokumi-active dipeptides.
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Affiliation(s)
- Jin Xie
- Department of Agricultural, Food and Nutritional Science, 4-10 Ag/For Centre, University of Alberta, Edmonton, AB, T6G 2P5, Canada
| | - Michael G Gänzle
- Department of Agricultural, Food and Nutritional Science, 4-10 Ag/For Centre, University of Alberta, Edmonton, AB, T6G 2P5, Canada.
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5
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Genomic and physiological insights into the lifestyle of Bifidobacterium species from water kefir. Arch Microbiol 2020; 202:1627-1637. [PMID: 32266422 DOI: 10.1007/s00203-020-01870-7] [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: 01/09/2020] [Revised: 02/26/2020] [Accepted: 03/20/2020] [Indexed: 12/13/2022]
Abstract
Water kefir is a fermented beverage employing a natural microbial consortium, which harbours bifidobacteria, namely Bifidobacterium aquikefiri and Bifidobacterium tibiigranuli. However, little information is available on their metabolic properties or role in the consortium. In this study, we combined genomic and physiologic investigations to predict and characterize the properties of these organisms and their possible role in the consortium. When comparing the genomes of these psychrotrophic organisms with that of the three selected mesophilic probiotic Bifidobacterium strains, we could find 143 genes shared by the 3 known isolates of bifidobacteria from water kefir that do not occur in the probiotic strains. These include genes involved in acid and oxygen tolerance. In addition, their genomically predicted carbohydrate usage and transport suggest adaptation to sucrose and other plant-related sugars. Furthermore, they proved prototrophic for all amino acids in vitro, which enables them to cope with the strong amino acid limitation in water kefir.
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6
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Choo K, Kim M, Nansa SA, Bae MK, Lee C, Lee SJ. Redox potential change by the cystine importer affected on enzymatic antioxidant protection in Deinococcus geothermalis. Antonie van Leeuwenhoek 2020; 113:779-790. [PMID: 31993844 DOI: 10.1007/s10482-020-01388-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Accepted: 01/21/2020] [Indexed: 10/25/2022]
Abstract
Radiation resistant bacteria genus Deinococcus species were well studied on DNA repair and anti-oxidative stress response mechanisms. There are many protection factors as enzymatic and nonenzymatic involved. One of them is intracellular redox potential as like thiol compounds including cysteine acts as primary protectant against oxidation stress. A gene cluster consisting of the genes Dgeo_1986 and Dgeo_1987 of Deinococcus geothermalis was identified as a cystine importer. The expression levels of dgeo_1986 and dgeo_1987 were up-regulated by over 60-fold and 4-fold during the late exponential (L) growth phase, respectively. The double-knockout mutant of dgeo_1986 and dgeo_1987 was reduced in cystine and thiol concentrations and leading to enhanced sensitivity against H2O2 stress. The expression of catalase (Dgeo_2728) as an enzymatic anti-oxidant is more induced in the wild-type strain than the Δdgeo_1986-87 strain at the late growth phase. The expression level of the oxidative stress response regulator OxyR (Dgeo_1888) is dependent on the intracellular redox balance. That is, when the intracellular thiol content was reduced in the wild-type strain during the L phase, OxyR was clearly induced. Interestingly, the expression level of OxyR was higher in the Δdgeo_1986-87 strain than in the wild-type strain upon H2O2 treatment. Although OxyR was induced by H2O2 treatment in Δdgeo_1986-87 strain, where intracellular redox potential of cystine was reduced as a thiol compound due to reduced cystine import, the relative level of expression of catalase was unexpectedly down-regulated. Therefore, the catalase induction system as an enzymatic antioxidant protection should be affected via the cystine importer but not rely on the OxyR controlled manner.
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Affiliation(s)
- Kyungsil Choo
- Department of Biology, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Korea
| | - Minwook Kim
- Department of Biology, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Korea.,Department of Developmental Biology, Pittsburgh Liver Research Center, McGowan Institute for Regenerative Medicine, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Sama Abdi Nansa
- Department of Biology, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Korea
| | - Min K Bae
- Department of Biology, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Korea
| | - Chanjae Lee
- Department of Biology, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Korea
| | - Sung-Jae Lee
- Department of Biology, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul, 02447, Korea.
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7
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Complex Responses to Hydrogen Peroxide and Hypochlorous Acid by the Probiotic Bacterium Lactobacillus reuteri. mSystems 2019; 4:4/5/e00453-19. [PMID: 31481604 PMCID: PMC6722424 DOI: 10.1128/msystems.00453-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Inflammatory diseases of the gut are associated with increased intestinal oxygen concentrations and high levels of inflammatory oxidants, including hydrogen peroxide (H2O2) and hypochlorous acid (HOCl), which are antimicrobial compounds produced by the innate immune system. This contributes to dysbiotic changes in the gut microbiome, including increased populations of proinflammatory enterobacteria (Escherichia coli and related species) and decreased levels of health-associated anaerobic Firmicutes and Bacteroidetes The pathways for H2O2 and HOCl resistance in E. coli have been well studied, but little is known about how commensal and probiotic bacteria respond to inflammatory oxidants. In this work, we have characterized the transcriptomic response of the anti-inflammatory, gut-colonizing Gram-positive probiotic Lactobacillus reuteri to both H2O2 and HOCl. L. reuteri mounts distinct but overlapping responses to each of these stressors, and both gene expression and survival were strongly affected by the presence or absence of oxygen. Oxidative stress response in L. reuteri required several factors not found in enterobacteria, including the small heat shock protein Lo18, polyphosphate kinase 2, and RsiR, an L. reuteri-specific regulator of anti-inflammatory mechanisms.IMPORTANCE Reactive oxidants, including hydrogen peroxide and hypochlorous acid, are antimicrobial compounds produced by the immune system during inflammation. Little is known, however, about how many important types of bacteria present in the human microbiome respond to these oxidants, especially commensal and other health-associated species. We have now mapped the stress response to both H2O2 and HOCl in the intestinal lactic acid bacterium Lactobacillus reuteri.
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Yan B, Chen YY, Wang W, Zhao J, Chen W, Gänzle M. γ-Glutamyl Cysteine Ligase of Lactobacillus reuteri Synthesizes γ-Glutamyl Dipeptides in Sourdough. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:12368-12375. [PMID: 30354106 DOI: 10.1021/acs.jafc.8b05056] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Kokumi-active γ-glutamyl dipeptides (γ-GPs) accumulate in fermented food. γ-Glutamyl transferase, glutaminase, glutathione synthetase, and γ-glutamyl cysteine ligase (GCL) may synthesize γ-GPs. The genome of Lactobacillus reuteri encodes GCL but not glutathione synthetase or glutamyl transferase; therefore, this study investigated the role of GCL in γ-GP synthesis by L. reuteri LTH5448. Phylogenomic analysis of gcl in lactobacilli demonstrated that three genes coding for GCL are present in L. reuteri; two of these are present in L. reuteri LTH5448. Two deletion mutants of L. reuteri LTH5448, L. reuteri LTH5448Δ gcl1 and LTH5448Δ gcl1Δ gcl2, were constructed by double crossover mutagenesis. Growth and oxygen resistance of the mutants were comparable to the wild type. γ-Glu-Glu, γ-Glu-Leu, γ-Glu-Ile, γ-Glu-Val, and γ-Glu-Cys were quantified in buffer and sourdough fermentations by liquid chromatography-mass spectrometry. The wild type and L. reuteri Δ gcl1 but not Δ gcl1Δ gcl2 converted amino acids to γ-Glu-Cys. γ-Glu-Ile accumulation was reduced in both mutants; however, the disruption of gcl did not alter the biosynthesis of the other γ-GPs. In conclusion, gcl1 in L. reuteri mediates γ-Glu-Ile synthesis, gcl2 mediates γ-Glu-Cys synthesis, but neither gene affected synthesis of other γ-GPs. This study facilitates selection of starter cultures that synthesize γ-Glu peptides with kokumi activity and, thus, improve the taste of fermented foods.
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Affiliation(s)
- Bowen Yan
- Department of Agricultural, Food and Nutritional Science , University of Alberta , Edmonton , Alberta T6G 2P5 , Canada
- School of Food Science and Technology , Jiangnan University , Wuxi , Jiangsu 214122 , People's Republic of China
| | - Yuan Yao Chen
- Department of Agricultural, Food and Nutritional Science , University of Alberta , Edmonton , Alberta T6G 2P5 , Canada
| | - Weilan Wang
- Department of Agricultural, Food and Nutritional Science , University of Alberta , Edmonton , Alberta T6G 2P5 , Canada
| | - Jianxin Zhao
- School of Food Science and Technology , Jiangnan University , Wuxi , Jiangsu 214122 , People's Republic of China
| | - Wei Chen
- School of Food Science and Technology , Jiangnan University , Wuxi , Jiangsu 214122 , People's Republic of China
| | - Michael Gänzle
- Department of Agricultural, Food and Nutritional Science , University of Alberta , Edmonton , Alberta T6G 2P5 , Canada
- School of Food Science and Technology , Jiangnan University , Wuxi , Jiangsu 214122 , People's Republic of China
- College of Bioengineering and Food Science , Hubei University of Technology , Wuhan Hubei 430068 , People's Republic of China
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9
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Montanari C, Barbieri F, Magnani M, Grazia L, Gardini F, Tabanelli G. Phenotypic Diversity of Lactobacillus sakei Strains. Front Microbiol 2018; 9:2003. [PMID: 30210476 PMCID: PMC6121134 DOI: 10.3389/fmicb.2018.02003] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 08/08/2018] [Indexed: 11/13/2022] Open
Abstract
Lactobacillus sakei is a lactic acid bacteria (LAB) species highly adapted to the meat environment. For this reason, selected strains are often used as starter culture in the production of fermented sausages, especially in Mediterranean countries. It often represents the dominant species in these products and can maintain its viability during all the ripening period, which can take also some months. This ability is guaranteed by the possibility of the species to obtain energy through pathways active even when hexoses are depleted. This species is characterized by a relevant genetic and phenotypic diversity and its metabolism can be further affected by the growth condition applied. In this work we investigate the metabolic responses of six different L. sakei in a synthetic medium (DM) containing defined amounts of amino acids in relation to temperature and NaCl concentration. In addition, the activities of cells pre-grown in presence of glucose o ribose were tested. Arginine was efficiently up-taken with the exception of the type strain DSMZ 20017t. Other amino acids (i.e., serine, asparagine, cysteine, and methionine) were metabolized through potentially energetic pathways which start from pyruvate accumulation, as demonstrated by the organic acid accumulation trend in the condition tested, especially in DM without sugar added. The presence of excesses of pyruvate deriving from amino acids lead to the accumulation of diacetyl and acetoin by all the strains when sugars were added. This approach allowed a deeper insight into the phenotypic variability of the species and improved the comprehension of the metabolic pathways adopted by L. sakei to survive and grow in restrictive conditions such as those found in fermented sausages during fermentations. Thus, the results obtained are useful information for improving and optimizing the use of such strains as starter culture for these products.
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Affiliation(s)
- Chiara Montanari
- Interdepartmental Center for Industrial Agri-Food Research, University of Bologna, Cesena, Italy
| | - Federica Barbieri
- Interdepartmental Center for Industrial Agri-Food Research, University of Bologna, Cesena, Italy
| | - Michael Magnani
- Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy
| | - Luigi Grazia
- Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy
| | - Fausto Gardini
- Interdepartmental Center for Industrial Agri-Food Research, University of Bologna, Cesena, Italy.,Department of Agricultural and Food Sciences, University of Bologna, Bologna, Italy
| | - Giulia Tabanelli
- Interdepartmental Center for Industrial Agri-Food Research, University of Bologna, Cesena, Italy
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Lo R, Ho VTT, Bansal N, Turner MS. The genetic basis underlying variation in production of the flavour compound diacetyl by Lactobacillus rhamnosus strains in milk. Int J Food Microbiol 2018; 265:30-39. [DOI: 10.1016/j.ijfoodmicro.2017.10.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 08/01/2017] [Accepted: 10/28/2017] [Indexed: 01/16/2023]
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11
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Choi PH, Vu TMN, Pham HT, Woodward JJ, Turner MS, Tong L. Structural and functional studies of pyruvate carboxylase regulation by cyclic di-AMP in lactic acid bacteria. Proc Natl Acad Sci U S A 2017; 114:E7226-E7235. [PMID: 28808024 PMCID: PMC5584425 DOI: 10.1073/pnas.1704756114] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cyclic di-3',5'-adenosine monophosphate (c-di-AMP) is a broadly conserved bacterial second messenger that has been implicated in a wide range of cellular processes. Our earlier studies showed that c-di-AMP regulates central metabolism in Listeria monocytogenes by inhibiting its pyruvate carboxylase (LmPC), a biotin-dependent enzyme with biotin carboxylase (BC) and carboxyltransferase (CT) activities. We report here structural, biochemical, and functional studies on the inhibition of Lactococcus lactis PC (LlPC) by c-di-AMP. The compound is bound at the dimer interface of the CT domain, at a site equivalent to that in LmPC, although it has a distinct binding mode in the LlPC complex. This binding site is not well conserved among PCs, and only a subset of these bacterial enzymes are sensitive to c-di-AMP. Conformational changes in the CT dimer induced by c-di-AMP binding may be the molecular mechanism for its inhibitory activity. Mutations of residues in the binding site can abolish c-di-AMP inhibition. In L. lactis, LlPC is required for efficient milk acidification through its essential role in aspartate biosynthesis. The aspartate pool in L. lactis is negatively regulated by c-di-AMP, and high aspartate levels can be restored by expression of a c-di-AMP-insensitive LlPC. LlPC has high intrinsic catalytic activity and is not sensitive to acetyl-CoA activation, in contrast to other PC enzymes.
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Affiliation(s)
- Philip H Choi
- Department of Biological Sciences, Columbia University, New York, NY 10027
| | - Thu Minh Ngoc Vu
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | - Huong Thi Pham
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | - Joshua J Woodward
- Department of Microbiology, University of Washington, Seattle, WA 98195
| | - Mark S Turner
- School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD 4072, Australia
| | - Liang Tong
- Department of Biological Sciences, Columbia University, New York, NY 10027;
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12
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Pophaly SD, Poonam S, Pophaly SD, Kapila S, Nanda DK, Tomar SK, Singh R. Glutathione biosynthesis and activity of dependent enzymes in food-grade lactic acid bacteria harbouring multidomain bifunctional fusion gene (gshF). J Appl Microbiol 2017; 123:194-203. [PMID: 28403558 DOI: 10.1111/jam.13471] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 12/20/2016] [Accepted: 04/07/2017] [Indexed: 12/20/2022]
Abstract
AIMS To assess glutathione (GSH) biosynthesis ability and activity of dependent enzymes in food-grade lactic acid bacteria (LAB) and correlating with genomic information on GSH system in LAB. METHODS AND RESULTS Whole-genome sequences of 26 food-grade LAB were screened for the presence/absence of a set of genes involved in de novo GSH system. Multiple strains of Streptococcus thermophilus (37), Lactobacillus casei (37), Lactobacillus rhamnosus (4), Lactobacillus paracasei (8) Lactobacillus plantarum (23) and Lactobacillus fermentum (22) were screened for biochemical evidence of the GSH system. Multiple sequence analysis of GshF sequences was carried out for comparing the genomic signatures between GSH-producing and nonproducing species. CONCLUSIONS Streptococcus thermophilus was found to have de novo GSH biosynthesis as well as import ability. Lactobacillus sp. were negative for GSH synthesis but could import it from the medium. All the species exhibited prolific GSH reductase and peroxidase activity. Sequence analysis revealed the absence of key amino acid residues as well as a truncated N-terminal region in lactobacilli. SIGNIFICANCE AND IMPACT OF THE STUDY The study provides a comprehensive view on the status of an important antioxidative system (the GSH system) in LAB and is expected to serve as a primer for future work on the mechanistic role of GSH in the group.
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Affiliation(s)
- S D Pophaly
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India.,Department of Dairy Microbiology, College of Dairy Science and Food Technology, Chhattisgarh Kamdhenu Vishwavidyalaya, Raipur, Chhattisgarh, India
| | - S Poonam
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India
| | - S D Pophaly
- Section of Population Genetics, School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany
| | - S Kapila
- Animal Biochemistry Division, National Dairy Research Institute, Karnal, Haryana, India
| | - D K Nanda
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India
| | - S K Tomar
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India
| | - R Singh
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India.,Directorate of Knowledge Management in Agriculture, Indian Council of Agricultural Research, New Delhi, India
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13
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Kim M, Jeong S, Lim S, Sim J, Rhie HG, Lee SJ. Oxidative stress response of Deinococcus geothermalis via a cystine importer. J Microbiol 2017; 55:137-146. [PMID: 28120190 DOI: 10.1007/s12275-017-6382-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/25/2016] [Accepted: 10/26/2016] [Indexed: 11/29/2022]
Abstract
A cystine-dependent anti-oxidative stress response is characterized in Deinococcus geothermalis for the first time. Nevertheless, the same transcriptional directed Δdgeo_1985F mutant strain was revealed to have an identical phenotype to the wild-type strain, while the reverse transcriptional directed Δdgeo_1985R mutant strain was more resistant to oxidative stress at a certain concentration of H2O2 than the wild-type strain. The wild-type and mutant strains expressed equal levels of superoxide dismutase and catalase under H2O2-induced stress. Although the expression levels of the general DNA-damage response-related genes recA, pprA, ddrA, and ddrB were up-regulated by more than five-fold in the wild-type strain relative to the Δdgeo_1985R mutant strain, the mutant strain had a higher survival rate than the wild-type under H2O2 stress. The Δdgeo_1985R mutant strain highly expressed a cystine-transporter gene (dgeo_1986), at levels 150-fold higher than the wild-type strain, leading to the conclusion that this cystine transporter might be involved in the defensive response to H2O2 stress. In this study, the cystine transporter was identified and characterized through membrane protein expression analysis, a cystine-binding assay, and assays of intracellular H2O2, cysteine, and thiol levels. The genedisrupted mutant strain of the cystine importer revealed high sensitivity to H2O2 and less absorbed cystine, resulting in low concentrations of total thiol. Thus, the absorbed cystine via this cystine-specific importer may be converted into cysteine, which acts as a primitive defense substrate that non-enzymatically scavenges oxidative stress agents in D. geothermalis.
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Affiliation(s)
- Minwook Kim
- Department of Biology, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Sunwook Jeong
- Division of Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, 56212, Republic of Korea
| | - Sangyong Lim
- Division of Biotechnology, Korea Atomic Energy Research Institute, Jeongeup, 56212, Republic of Korea
| | - Jeonggu Sim
- Department of Visual Optics, Baekseok University, Cheonan, 31065, Republic of Korea
| | - Ho-Gun Rhie
- Department of Biology, Kyung Hee University, Seoul, 02447, Republic of Korea
| | - Sung-Jae Lee
- Department of Biology, Kyung Hee University, Seoul, 02447, Republic of Korea. .,Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul, 02447, Republic of Korea.
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14
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Krumbeck JA, Marsteller NL, Frese SA, Peterson DA, Ramer-Tait AE, Hutkins RW, Walter J. Characterization of the ecological role of genes mediating acid resistance in Lactobacillus reuteri during colonization of the gastrointestinal tract. Environ Microbiol 2015; 18:2172-84. [PMID: 26530032 DOI: 10.1111/1462-2920.13108] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 10/27/2015] [Indexed: 02/06/2023]
Abstract
Rodent-derived strains of Lactobacillus reuteri densely colonize the forestomach of mice and possess several genes whose predicted functions constitute adaptations towards an acidic environment. The objective of this study was to systematically determine which genes of L. reuteri 100-23 contribute to tolerance towards host gastric acid secretion. Genes predicted to be involved in acid resistance were inactivated, and their contribution to survival under acidic conditions was confirmed in model gastric juice. Fitness of five mutants that showed impaired in vitro acid resistance were then compared through competition experiments in ex-germ-free mice that were either treated with omeprazole, a proton-pump inhibitor that suppresses acid secretion in the stomach, or left untreated. This analysis revealed that the urease cluster was the predominant factor in mediating resistance to gastric acid production. Population levels of the mutant, which were substantially decreased in untreated mice, were almost completely restored through omeprazole, demonstrating that urease production in L. reuteri is mainly devoted to overcome gastric acid. The findings provide novel information on the mechanisms by which L. reuteri colonizes its gastric niche and demonstrate that in silico gene predictions and in vitro tests have limitations for predicting the ecological functions of colonization factors in bacterial symbionts.
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Affiliation(s)
- Janina A Krumbeck
- Department of Food Science and Technology, University of Nebraska, Lincoln, NE, USA.,School of Biological Sciences, University of Nebraska, Lincoln, NE, USA
| | - Nathan L Marsteller
- Department of Food Science and Technology, University of Nebraska, Lincoln, NE, USA
| | - Steven A Frese
- Department of Food Science and Technology, University of Nebraska, Lincoln, NE, USA
| | - Daniel A Peterson
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Amanda E Ramer-Tait
- Department of Food Science and Technology, University of Nebraska, Lincoln, NE, USA
| | - Robert W Hutkins
- Department of Food Science and Technology, University of Nebraska, Lincoln, NE, USA
| | - Jens Walter
- Department of Food Science and Technology, University of Nebraska, Lincoln, NE, USA.,Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, AB, Canada.,Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
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15
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Death by Cystine: an Adverse Emergent Property from a Beneficial Series of Reactions. J Bacteriol 2015; 197:3626-8. [PMID: 26369582 DOI: 10.1128/jb.00546-15] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
In this issue of the Journal of Bacteriology, Chonoles Imlay et al. (K. R. Chonoles Imlay, S. Korshunov, and J. A. Imlay, J Bacteriol 197:3629-3644, 2015, http://dx.doi.org/10.1128/JB.00277-15) show that oxidative stress kills sulfur-restricted Escherichia coli grown with sublethal H2O2 when challenged with cystine. Killing requires rapid and seemingly unregulated cystine transport and equally rapid cystine reduction to cysteine. Cysteine export completes an energy-depleting futile cycle. Each reaction of the cycle could be beneficial. Together, a cystine-mediated vulnerability emerges during the transition from a sulfur-restricted to a sulfur-replete environment, perhaps because of complexities of sulfur metabolism.
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16
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Ohtsu I, Kawano Y, Suzuki M, Morigasaki S, Saiki K, Yamazaki S, Nonaka G, Takagi H. Uptake of L-cystine via an ABC transporter contributes defense of oxidative stress in the L-cystine export-dependent manner in Escherichia coli. PLoS One 2015; 10:e0120619. [PMID: 25837721 PMCID: PMC4383340 DOI: 10.1371/journal.pone.0120619] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 01/24/2015] [Indexed: 11/18/2022] Open
Abstract
Intracellular thiols like L-cystine and L-cystine play a critical role in the regulation of cellular processes. Here we show that Escherichia coli has two L-cystine transporters, the symporter YdjN and the ATP-binding cassette importer FliY-YecSC. These proteins import L-cystine, an oxidized product of L-cystine from the periplasm to the cytoplasm. The symporter YdjN, which is expected to be a new member of the L-cystine regulon, is a low affinity L-cystine transporter (Km = 1.1 μM) that is mainly involved in L-cystine uptake from outside as a nutrient. E. coli has only two L-cystine importers because ΔydjNΔyecS mutant cells are not capable of growing in the minimal medium containing L-cystine as a sole sulfur source. Another protein YecSC is the FliY-dependent L-cystine transporter that functions cooperatively with the L-cystine transporter YdeD, which exports L-cystine as reducing equivalents from the cytoplasm to the periplasm, to prevent E. coli cells from oxidative stress. The exported L-cystine can reduce the periplasmic hydrogen peroxide to water, and then generated L-cystine is imported back into the cytoplasm via the ATP-binding cassette transporter YecSC with a high affinity to L-cystine (Km = 110 nM) in a manner dependent on FliY, the periplasmic L-cystine-binding protein. The double disruption of ydeD and fliY increased cellular levels of lipid peroxides. From these findings, we propose that the hydrogen peroxide-inducible L-cystine/L-cystine shuttle system plays a role of detoxification of hydrogen peroxide before lipid peroxidation occurs, and then might specific prevent damage to membrane lipids.
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Affiliation(s)
- Iwao Ohtsu
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan
- * E-mail:
| | - Yusuke Kawano
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan
| | - Marina Suzuki
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan
| | - Susumu Morigasaki
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan
| | - Kyohei Saiki
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan
| | - Shunsuke Yamazaki
- Research Institute for Bioscience Products and Fine Chemicals, Ajinomoto Company, Kawasaki, Kanagawa, Japan
| | - Gen Nonaka
- Research Institute for Bioscience Products and Fine Chemicals, Ajinomoto Company, Kawasaki, Kanagawa, Japan
| | - Hiroshi Takagi
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan
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17
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He X, Slupsky CM. Metabolic fingerprint of dimethyl sulfone (DMSO2) in microbial-mammalian co-metabolism. J Proteome Res 2014; 13:5281-92. [PMID: 25245235 DOI: 10.1021/pr500629t] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
There is growing awareness that intestinal microbiota alters the energy harvesting capacity of the host and regulates metabolism. It has been postulated that intestinal microbiota are able to degrade unabsorbed dietary components and transform xenobiotic compounds. The resulting microbial metabolites derived from the gastrointestinal tract can potentially enter the circulation system, which, in turn, affects host metabolism. Yet, the metabolic capacity of intestinal microbiota and its interaction with mammalian metabolism remains largely unexplored. Here, we review a metabolic pathway that integrates the microbial catabolism of methionine with mammalian metabolism of methanethiol (MT), dimethyl sulfide (DMS), and dimethyl sulfoxide (DMSO), which together provide evidence that supports the microbial origin of dimethyl sulfone (DMSO2) in the human metabolome. Understanding the pathway of DMSO2 co-metabolism expends our knowledge of microbial-derived metabolites and motivates future metabolomics-based studies on ascertaining the metabolic consequences of intestinal microbiota on human health, including detoxification processes and sulfur xenobiotic metabolism.
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Affiliation(s)
- Xuan He
- Department of Nutrition, Department of Food Science and Technology, One Shields Avenue , University of California, Davis, Davis, California 95616, United States
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18
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An H, Douillard FP, Wang G, Zhai Z, Yang J, Song S, Cui J, Ren F, Luo Y, Zhang B, Hao Y. Integrated transcriptomic and proteomic analysis of the bile stress response in a centenarian-originated probiotic Bifidobacterium longum BBMN68. Mol Cell Proteomics 2014; 13:2558-72. [PMID: 24965555 DOI: 10.1074/mcp.m114.039156] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Bifidobacteria are natural inhabitants of the human gastrointestinal tract and well known for their health-promoting effects. Tolerance to bile stress is crucial for bifidobacteria to survive in the colon and to exert their beneficial actions. In this work, RNA-Seq transcriptomic analysis complemented with proteomic analysis was used to investigate the cellular response to bile in Bifidobacterium longum BBMN68. The transcript levels of 236 genes were significantly changed (≥ threefold, p < 0.001) and 44 proteins were differentially abundant (≥1.6-fold, p < 0.01) in B. longum BBMN68 when exposed to 0.75 g l(-1) ox-bile. The hemolysin-like protein and bile efflux systems were significantly over produced, which might prevent bile adsorption and exclude bile, respectively. The cell membrane composition was modified probably by an increase of cyclopropane fatty acid and a decrease of transmembrane proteins, resulting in a cell membrane more impermeable to bile salts. Our hypothesis was later confirmed by surface hydrophobicity assay. The transcription of genes related to xylose utilization and bifid shunt were up-regulated, which increased the production of ATP and reducing equivalents to cope with bile-induced damages in a xylan-rich colon environment. Bile salts signal the B. longum BBMN68 to gut entrance and enhance the expression of esterase and sortase associated with adhesion and colonization in intestinal tract, which was supported by a fivefold increased adhesion ability to HT-29 cells by BBMN68 upon bile exposure. Notably, bacterial one-hybrid and EMSA assay revealed that the two-component system senX3-regX3 controlled the expression of pstS in bifidobacteria and the role of this target gene in bile resistance was further verified by heterologous expression in Lactococcus lactis. Taken altogether, this study established a model for global response mechanisms in B. longum to bile.
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Affiliation(s)
- Haoran An
- From the ‡Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - François P Douillard
- §Department of Veterinary Biosciences, University of Helsinki, Helsinki, Finland
| | - Guohong Wang
- From the ‡Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Zhengyuan Zhai
- From the ‡Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Jin Yang
- ¶Core Genomic Facility, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Shuhui Song
- ¶Core Genomic Facility, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Jianyun Cui
- From the ‡Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Fazheng Ren
- From the ‡Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Yunbo Luo
- From the ‡Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Bing Zhang
- ¶Core Genomic Facility, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yanling Hao
- From the ‡Key Laboratory of Functional Dairy, Co-constructed by Ministry of Education and Beijing Municipality, College of Food Science & Nutritional Engineering, China Agricultural University, Beijing 100083, China;
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The transcriptional response of Lactobacillus sanfranciscensis DSM 20451T and its tcyB mutant lacking a functional cystine transporter to diamide stress. Appl Environ Microbiol 2014; 80:4114-25. [PMID: 24795368 DOI: 10.1128/aem.00367-14] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
As a result of its strong adaptation to wheat and rye sourdoughs, Lactobacillus sanfranciscensis has the smallest genome within the genus Lactobacillus. The concomitant absence of some important antioxidative enzymes and the inability to synthesize glutathione suggest a role of cystine transport in maintenance of an intracellular thiol balance. Diamide [synonym 1,1'-azobis(N,N-dimethylformamide)] disturbs intracellular and membrane thiol levels in oxidizing protein thiols depending on its initial concentration. In this study, RNA sequencing was used to reveal the transcriptional response of L. sanfranciscensis DSM 20451(T) (wild type [WT]) and its ΔtcyB mutant with a nonfunctional cystine transporter after thiol stress caused by diamide. Along with the different expression of genes involved in amino acid starvation, pyrimidine synthesis, and energy production, our results show that thiol stress in the wild type can be compensated through activation of diverse chaperones and proteases whereas the ΔtcyB mutant shifts its metabolism in the direction of survival. Only a small set of genes are significantly differentially expressed between the wild type and the mutant. In the WT, mainly genes which are associated with a heat shock response are upregulated whereas glutamine import and synthesis genes are downregulated. In the ΔtcyB mutant, the whole opp operon was more highly expressed, as well as a protein which probably includes enzymes for methionine transport. The two proteins encoded by spxA and nrdH, which are involved in direct or indirect oxidative stress responses, are also upregulated in the mutant. This work emphasizes that even in the absence of definitive antioxidative enzymes, bacteria with a small genome and a high frequency of gene inactivation and elimination use small molecules such as the cysteine/cystine couple to overcome potential cell damage resulting from oxidative stress.
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20
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Zhang Y, Li Y. Engineering the antioxidative properties of lactic acid bacteria for improving its robustness. Curr Opin Biotechnol 2013; 24:142-7. [DOI: 10.1016/j.copbio.2012.08.013] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2012] [Revised: 08/22/2012] [Accepted: 08/30/2012] [Indexed: 10/27/2022]
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21
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Pophaly SD, Singh R, Pophaly SD, Kaushik JK, Tomar SK. Current status and emerging role of glutathione in food grade lactic acid bacteria. Microb Cell Fact 2012; 11:114. [PMID: 22920585 PMCID: PMC3462692 DOI: 10.1186/1475-2859-11-114] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2012] [Accepted: 08/18/2012] [Indexed: 12/15/2022] Open
Abstract
Lactic acid bacteria (LAB) have taken centre stage in perspectives of modern fermented food industry and probiotic based therapeutics. These bacteria encounter various stress conditions during industrial processing or in the gastrointestinal environment. Such conditions are overcome by complex molecular assemblies capable of synthesizing and/or metabolizing molecules that play a specific role in stress adaptation. Thiols are important class of molecules which contribute towards stress management in cell. Glutathione, a low molecular weight thiol antioxidant distributed widely in eukaryotes and Gram negative organisms, is present sporadically in Gram positive bacteria. However, new insights on its occurrence and role in the latter group are coming to light. Some LAB and closely related Gram positive organisms are proposed to possess glutathione synthesis and/or utilization machinery. Also, supplementation of glutathione in food grade LAB is gaining attention for its role in stress protection and as a nutrient and sulfur source. Owing to the immense benefits of glutathione, its release by probiotic bacteria could also find important applications in health improvement. This review presents our current understanding about the status of glutathione and its role as an exogenously added molecule in food grade LAB and closely related organisms.
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Affiliation(s)
- Sarang Dilip Pophaly
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India, 132001
| | - Rameshwar Singh
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India, 132001
| | | | - Jai K Kaushik
- Animal Biotechnology Centre, National Dairy Research Institute, Karnal, Haryana, India, 132001
| | - Sudhir Kumar Tomar
- Dairy Microbiology Division, National Dairy Research Institute, Karnal, Haryana, India, 132001
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22
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Heat resistance and salt hypersensitivity in Lactococcus lactis due to spontaneous mutation of llmg_1816 (gdpP) induced by high-temperature growth. Appl Environ Microbiol 2012; 78:7753-9. [PMID: 22923415 DOI: 10.1128/aem.02316-12] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
During construction of several gene deletion mutants in Lactococcus lactis MG1363 which involved a high-temperature (37.5°C) incubation step, additional spontaneous mutations were observed which resulted in stable heat resistance and in some cases salt-hypersensitive phenotypes. Whole-genome sequencing of one strain which was both heat resistant and salt hypersensitive, followed by PCR and sequencing of four other mutants which shared these phenotypes, revealed independent mutations in llmg_1816 in all cases. This gene encodes a membrane-bound stress signaling protein of the GdpP family, members of which exhibit cyclic dimeric AMP (c-di-AMP)-specific phosphodiesterase activity. Mutations were predicted to lead to single amino acid substitutions or protein truncations. An independent llmg_1816 mutant (Δ1816), created using a suicide vector, also displayed heat resistance and salt hypersensitivity phenotypes which could be restored to wild-type levels following plasmid excision. L. lactis Δ1816 also displayed improved growth in response to sublethal concentrations of penicillin G. High-temperature incubation of a wild-type industrial L. lactis strain also resulted in spontaneous mutation of llmg_1816 and heat-resistant and salt-hypersensitive phenotypes, suggesting that this is not a strain-specific phenomenon and that it is independent of a plasmid integration event. Acidification of milk by the llmg_1816-altered strain was inhibited by lower salt concentrations than the parent strain. This study demonstrates that spontaneous mutations can occur during high-temperature growth of L. lactis and that inactivation of llmg_1816 leads to temperature resistance and salt hypersensitivity.
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Effects of a Lactobacillus reuteri BR11 mutant deficient in the cystine-transport system in a rat model of inflammatory bowel disease. Dig Dis Sci 2012; 57:713-9. [PMID: 22038505 DOI: 10.1007/s10620-011-1943-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 10/08/2011] [Indexed: 12/22/2022]
Abstract
BACKGROUND Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract associated with altered composition of the gut microbiota. Lactobacillus reuteri BR11 (BR11) has recently been reported to reduce the severity of experimental IBD because of its probiotic properties possibly attributed to a mechanism of thiol production via its unique cysteine/cystine-transport system. AIM We compared BR11 and a BR11 mutant deficient in the cystine-uptake system (PNG201), for their capacity to reduce the severity of experimental colitis. METHODS Male Sprague-Dawley rats (n = 8 per group) were gavaged (1 ml/day) with skim milk, BR11 or PNG201 (1 × 10(9) CFU/ml) for 12 days. Rats consumed either water or 2% dextran sulfate sodium in drinking water from days 6 to 12 to induce colitis. Metabolism data, disease activity index, intestinal mucin profile, and histological analyses were assessed and compared by ANOVA. RESULTS Assessed histologically, DSS administration resulted in significant colonic deterioration, including loss of crypt area and increased damage severity. BR11 administration only partially alleviated the DSS effects, with a minor improvement in crypt area (P < 0.05). Administration of the PNG201 mutant strain to colitic animals failed to achieve significance (P > 0.05) against the DSS control for any of the end-points. However, the mutant strain induced significantly greater (P < 0.05) histological severity compared with BR11-treated colitic animals, indicative of possible exacerbation of colitis. CONCLUSIONS The cystine-uptake system only minimally affects the biological effects of BR11, as evidenced by histological and macroscopic colitic changes.
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Fanous A, Hecker M, Görg A, Parlar H, Jacob F. Corynebacterium glutamicum as an indicator for environmental cobalt and silver stress--a proteome analysis. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2010; 45:666-675. [PMID: 20818520 DOI: 10.1080/03601234.2010.502442] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Cobalt and silver are toxic for cells, but mechanisms of this toxicity are largely unknown. Analysis of Corynebacterium glutamicum proteome from cells grown in control and cobalt or silver enriched media was performed by two dimensional gel electrophoresis (2DE) followed by mass spectrometry. Our results indicate that the cell adapted to cobalt stress by inducing five defense mechanisms: Scavenging of free radicals, promotion of the generation of energy, reparation of DNA, reparation and biogenesis of Fe-S cluster proteins and supporting and reparation of cell wall. In response to the detoxification of Ag+ many proteins were up-regulated, which involved reparation of damaged DNA, minimizing the toxic effect of reactive oxygen species (ROS) and energy generation. Overexpression of proteins involved in cell wall biosynthesis (1,4-alpha-glucan branching enzyme and nucleoside-diphosphate-sugar epimerase) upon cobalt stress and induction of proteins involved in energy metabolism (2-methylcitrate dehydratase and 1, 2-methylcitrate synthase) upon silver demonstrate the potential of these enzymes as biomarkers of sub-lethal Ag+ and Co toxicity.
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Affiliation(s)
- Ali Fanous
- Department for Chemical-Technical Analysis and Chemical Food Technology, Research Center Weihenstephan for Brewing and Food Quality, Technische Universität München, Freising-Weihenstephan, Germany
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The pleiotropic CymR regulator of Staphylococcus aureus plays an important role in virulence and stress response. PLoS Pathog 2010; 6:e1000894. [PMID: 20485570 PMCID: PMC2869319 DOI: 10.1371/journal.ppat.1000894] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Accepted: 04/02/2010] [Indexed: 12/20/2022] Open
Abstract
We have characterized a novel pleiotropic role for CymR, the master regulator of cysteine metabolism. We show here that CymR plays an important role both in stress response and virulence of Staphylococcus aureus. Genes involved in detoxification processes, including oxidative stress response and metal ion homeostasis, were differentially expressed in a ΔcymR mutant. Deletion of cymR resulted in increased sensitivity to hydrogen peroxide-, disulfide-, tellurite- and copper-induced stresses. Estimation of metabolite pools suggests that this heightened sensitivity could be the result of profound metabolic changes in the ΔcymR mutant, with an increase in the intracellular cysteine pool and hydrogen sulfide formation. Since resistance to oxidative stress within the host organism is important for pathogen survival, we investigated the role of CymR during the infectious process. Our results indicate that the deletion of cymR promotes survival of S. aureus inside macrophages, whereas virulence of the ΔcymR mutant is highly impaired in mice. These data indicate that CymR plays a major role in virulence and adaptation of S. aureus for survival within the host. Staphylococcus aureus is a very harmful human pathogen that is a major cause of nosocomial infections. Humans have developed sophisticated defense strategies against invading bacteria, including the innate immune response, with the generation of an oxidative burst inside phagocytic cells. Staphylococcal infections are extremely difficult to eradicate due to the remarkable capacity of these bacteria to adapt to different environmental conditions both inside and outside the host organism. Sulfur metabolism is essential for all living organisms and is tightly controlled by regulatory proteins. In this paper, we revealed an important role for CymR, a major regulator of sulfur metabolism, in adaptation of S. aureus to the host environment. Inactivation of the gene encoding this regulator in S. aureus leads to a mutant bacterium with increased vulnerability to stress conditions including oxidative stress encountered inside the host. More importantly, the deletion of the cymR gene strongly affected the interaction of S. aureus with its host, leading to impaired virulence in mice. Our results place CymR among the potential targets for attenuation of S. aureus infections.
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De Vuyst L, Vrancken G, Ravyts F, Rimaux T, Weckx S. Biodiversity, ecological determinants, and metabolic exploitation of sourdough microbiota. Food Microbiol 2009; 26:666-75. [DOI: 10.1016/j.fm.2009.07.012] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2009] [Revised: 07/13/2009] [Accepted: 07/13/2009] [Indexed: 01/26/2023]
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