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Chen Z, Zhang Y, Mao D, Wang X, Luo Y. NaClO Co-selects antibiotic and disinfectant resistance in Klebsiella pneumonia: Implications for the potential risk of extensive disinfectant use during COVID-19 pandemic. JOURNAL OF HAZARDOUS MATERIALS 2024; 470:134102. [PMID: 38554506 DOI: 10.1016/j.jhazmat.2024.134102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 02/01/2024] [Accepted: 03/19/2024] [Indexed: 04/01/2024]
Abstract
The inappropriate use of antibiotics is widely recognized as the primary driver of bacterial antibiotic resistance. However, less attention has been given to the potential induction of multidrug-resistant bacteria through exposure to disinfectants. In this study, Klebsiella pneumonia, an opportunistic pathogen commonly associated with hospital and community-acquired infection, was experimentally exposed to NaClO at both minimum inhibitory concentration (MIC) and sub-MIC levels over a period of 60 days. The result demonstrated that NaClO exposure led to enhanced resistance of K. pneumonia to both NaClO itself and five antibiotics (erythromycin, polymyxin B, gentamicin, tetracycline, and ciprofloxacin). Concurrently, the evolved resistant strains exhibited fitness costs, as evidenced by decreased growth rates. Whole population sequencing revealed that both concentrations of NaClO exposure caused genetic mutations in the genome of K. pneumonia. Some of these mutations were known to be associated with antibiotic resistance, while others had not previously been identified as such. In addition, 11 identified mutations were located in the virulence factors, demonstrating that NaClO exposure may also impact the pathogenicity of K. pneumoniae. Overall, this study highlights the potential for the widespread use of NaClO-containing disinfectants during the COVID-19 pandemic to contribute to the emergence of antibiotic-resistant bacteria. ENVIRONMENTAL IMPLICATION: Considering the potential hazardous effects of disinfectant residues on environment, organisms and biodiversity, the sharp rise in use of disinfectants during COVID-19 pandemic has been considered highly likely to cause worldwide secondary disasters in ecosystems and human health. This study demonstrated that NaClO exposure enhanced the resistance of K. pneumonia to both NaClO and five antibiotics (erythromycin, polymyxin B, gentamicin, tetracycline, and ciprofloxacin), highlighting the widespread use of NaClO-containing disinfectants during the COVID-19 pandemic may increase the emergence of antibiotic-resistant bacteria in the environment.
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Affiliation(s)
- Zeyou Chen
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300071, China
| | - Yulin Zhang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300071, China
| | - Daqing Mao
- School of Medicine, Nankai University, Tianjin, China
| | - Xiaolong Wang
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300071, China.
| | - Yi Luo
- College of Environmental Science and Engineering, Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria, Nankai University, Tianjin 300071, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China.
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2
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Shu P, Zhang S, Li Y, Wang X, Yao L, Sheng J, Shen L. Over-expression of SlWRKY46 in tomato plants increases susceptibility to Botrytis cinerea by modulating ROS homeostasis and SA and JA signaling pathways. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2021; 166:1-9. [PMID: 34087740 DOI: 10.1016/j.plaphy.2021.05.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Accepted: 05/16/2021] [Indexed: 06/12/2023]
Abstract
WRKY, as one of the largest families of transcription factors (TFs), binds to cis-acting elements of downstream genes to regulate biotic and abiotic stress. However, the role of SlWRKY46 in fungal disease response induced by Botrytis cinerea (B.cinerea) and potential mechanism remains obscure. To ascertain the role of SlWRKY46 in response to B.cinerea, we constructed SlWRKY46-overexpression plants, which were then inoculated with B.cinerea. SlWRKY46-overexpression plants were more susceptible to B.cinerea and accompanied by the inhibited activities of phenylalanine ammonialyase (PAL), polyphenol oxidase (PPO), chitinase (CHI), and β-1,3-glucanase (GLU). Additionally, SlWRKY46-overexpression plants showed the decreased activities of ascorbate peroxidase (APX), superoxide dismutase (SOD) and the content of H2O2, and the increased content of O2•-. Moreover, over-expression of SlWRKY46 suppressed the salicylic acid (SA) and jasmonic acid (JA) marker genes, pathogenesis related protein (PR1), and proteinase inhibitors (PI Ⅰ and PI Ⅱ) and consequently aggravated the disease symptoms. Therefore, we speculated that SlWRKY46 played negative regulatory roles in B. cinerea infection probably by inhibiting the activities of antioxidants and disease resistance enzymes, regulating SA and JA signaling pathways and modulating reactive oxygen (ROS) homeostasis.
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Affiliation(s)
- Pan Shu
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Shujuan Zhang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Yujing Li
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Xinyu Wang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Lan Yao
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China
| | - Jiping Sheng
- School of Agricultural Economics and Rural Development, Renmin University of China, Beijing, 100872, China
| | - Lin Shen
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083, China.
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3
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Shu P, Li Z, Min D, Zhang X, Ai W, Li J, Zhou J, Li Z, Li F, Li X. CRISPR/Cas9-Mediated SlMYC2 Mutagenesis Adverse to Tomato Plant Growth and MeJA-Induced Fruit Resistance to Botrytis cinerea. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:5529-5538. [PMID: 32372640 DOI: 10.1021/acs.jafc.9b08069] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Methyl jasmonate (MeJA), a natural phytohormone, played a critical role not only in plant growth but also in plant defense response to biotic and abiotic stresses. MYC2, a basic helix-loop-helix transcription factor, is a master regulator in MeJA signaling pathway. In the present work, slmyc2 mutants were generated by the clustered regularly interspaced short palindromic repeats and associated Cas9 protein (CRISPR/Cas9) system to investigate the role of SlMYC2 in tomato plant growth and fruit disease resistance induced by exogenous MeJA. The results showed that slmyc2 mutants possessed a higher number of flowers and a lower fruit setting rate in comparison with wild-type plants. In addition, the fruit shape of slmyc2 mutant was prolate, while the control fruits were oblate. Knockout of SlMYC2 significantly decreased the activities of disease defensive and antioxidant enzymes, as well as the expression levels of pathogen-related (PR) genes (SlPR-1 and SlPR-STH2) and the key genes related to jasmonic acid (JA) biosynthesis and signaling pathway including allene oxide cyclase (SlAOC), lipoxygenase D (SlLOXD), SlMYC2, and coronatine insensitive 1 (SlCOI1), and consequently aggravated the disease symptoms. By contrast, the disease symptoms were largely reduced in MeJA-treated fruit that possessed higher activities of these enzymes and expression levels of genes. However, the induction effects of MeJA on fruit disease resistance and these enzymes' activities and genes' expressions were significantly attenuated by knockout of SlMYC2. Therefore, the results indicated that SlMYC2 played positive regulatory roles not only in the growth of tomato plants but also in MeJA-induced disease resistance and the antioxidant process in tomato fruits.
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Affiliation(s)
- Pan Shu
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255049 Shandong, P. R. China
| | - Ziye Li
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255049 Shandong, P. R. China
| | - Dedong Min
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255049 Shandong, P. R. China
| | - Xinhua Zhang
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255049 Shandong, P. R. China
| | - Wen Ai
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255049 Shandong, P. R. China
| | - Jiaozhuo Li
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255049 Shandong, P. R. China
| | - Jingxiang Zhou
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255049 Shandong, P. R. China
| | - Zilong Li
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255049 Shandong, P. R. China
| | - Fujun Li
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255049 Shandong, P. R. China
| | - Xiaoan Li
- School of Agricultural Engineering and Food Science, Shandong University of Technology, Zibo, 255049 Shandong, P. R. China
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Moody S, Bull J, Dudley E, Loveridge E. The impact of combinatorial stress on the growth dynamics and metabolome of
Burkholderia mesoacidophila
demonstrates the complexity of tolerance mechanisms. J Appl Microbiol 2019; 127:1521-1531. [DOI: 10.1111/jam.14404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/19/2019] [Accepted: 07/23/2019] [Indexed: 12/15/2022]
Affiliation(s)
- S.C. Moody
- College of Science Swansea University Swansea UK
- School of Sport, Health and Social Sciences Solent University Southampton UK
| | - J.C. Bull
- College of Science Swansea University Swansea UK
| | - E. Dudley
- College of Medicine Swansea University Swansea UK
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Niche Construction and Exploitation by Agrobacterium: How to Survive and Face Competition in Soil and Plant Habitats. Curr Top Microbiol Immunol 2018; 418:55-86. [PMID: 29556826 DOI: 10.1007/82_2018_83] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Agrobacterium populations live in different habitats (bare soil, rhizosphere, host plants), and hence face different environmental constraints. They have evolved the capacity to exploit diverse resources and to escape plant defense and competition from other microbiota. By modifying the genome of their host, Agrobacterium populations exhibit the remarkable ability to construct and exploit the ecological niche of the plant tumors that they incite. This niche is characterized by the accumulation of specific, low molecular weight compounds termed opines that play a critical role in Agrobacterium 's lifestyle. We present and discuss the functions, advantages, and costs associated with this niche construction and exploitation.
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Joghee NN, Gurunathan J. Planococcus maritimus VITP21 synthesizes (2-acetamido-2-deoxy-α-d-glucopyranosyl)-(1→2)-β-d-fructofuranose under osmotic stress: a novel protein stabilizing sugar osmolyte. Carbohydr Res 2013; 383:76-81. [PMID: 24333897 DOI: 10.1016/j.carres.2013.11.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 11/09/2013] [Accepted: 11/16/2013] [Indexed: 11/16/2022]
Abstract
A halotolerant bacterium, Planococcus maritimus VITP21 isolated from a saltern region in Kumta along the Arabian Sea Coast of India was found to have increased cellular levels of sugars (up to 2.3-fold) under osmotic stress when grown in minimal medium with glucose as the sole carbon and energy source supplemented with 10% w/v NaCl. The major sugar osmolyte which increased with the concentration of NaCl in the growth medium was purified and characterized using various nuclear magnetic resonance spectroscopy techniques. The sugar was found to be similar to sucrose but with the C-2 hydroxyl group of the glucose ring substituted with acetamido group, which is not previously reported for its natural synthesis by any other organism. This novel sugar, (2-acetamido-2-deoxy-α-d-glucopyranosyl)-(1→2)-β-d-fructofuranose, exhibited stabilizing effect on a model protein α-amylase by increasing the apparent midpoint transition, onset temperature of denaturation, and free energy of thermal unfolding.
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7
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Choline uptake in Agrobacterium tumefaciens by the high-affinity ChoXWV transporter. J Bacteriol 2011; 193:5119-29. [PMID: 21803998 DOI: 10.1128/jb.05421-11] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Agrobacterium tumefaciens is a facultative phytopathogen that causes crown gall disease. For successful plant transformation A. tumefaciens requires the membrane lipid phosphatidylcholine (PC), which is produced via the methylation and the PC synthase (Pcs) pathways. The latter route is dependent on choline. Although choline uptake has been demonstrated in A. tumefaciens, the responsible transporter(s) remained elusive. In this study, we identified the first choline transport system in A. tumefaciens. The ABC-type choline transporter is encoded by the chromosomally located choXWV operon (ChoX, binding protein; ChoW, permease; and ChoV, ATPase). The Cho system is not critical for growth and PC synthesis. However, [14C]choline uptake is severely reduced in A. tumefaciens choX mutants. Recombinant ChoX is able to bind choline with high affinity (equilibrium dissociation constant [KD] of ≈2 μM). Since other quaternary amines are bound by ChoX with much lower affinities (acetylcholine, KD of ≈80 μM; betaine, KD of ≈470 μM), the ChoXWV system functions as a high-affinity transporter with a preference for choline. Two tryptophan residues (W40 and W87) located in the predicted ligand-binding pocket are essential for choline binding. The structural model of ChoX built on Sinorhizobium meliloti ChoX resembles the typical structure of substrate binding proteins with a so-called "Venus flytrap mechanism" of substrate binding.
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8
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Somero GN, Yancey PH. Osmolytes and Cell‐Volume Regulation: Physiological and Evolutionary Principles. Compr Physiol 2011. [DOI: 10.1002/cphy.cp140110] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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9
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Fernandez-Aunión C, Hamouda TB, Iglesias-Guerra F, Argandoña M, Reina-Bueno M, Nieto JJ, Aouani ME, Vargas C. Biosynthesis of compatible solutes in rhizobial strains isolated from Phaseolus vulgaris nodules in Tunisian fields. BMC Microbiol 2010; 10:192. [PMID: 20633304 PMCID: PMC2918589 DOI: 10.1186/1471-2180-10-192] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2010] [Accepted: 07/16/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Associated with appropriate crop and soil management, inoculation of legumes with microbial biofertilizers can improve food legume yield and soil fertility and reduce pollution by inorganic fertilizers. Rhizospheric bacteria are subjected to osmotic stress imposed by drought and/or NaCl, two abiotic constraints frequently found in semi-arid lands. Osmostress response in bacteria involves the accumulation of small organic compounds called compatible solutes. Whereas most studies on rhizobial osmoadaptation have focussed on the model species Sinorhizobium meliloti, little is known on the osmoadaptive mechanisms used by native rhizobia, which are good sources of inoculants. In this work, we investigated the synthesis and accumulations of compatible solutes by four rhizobial strains isolated from root nodules of Phaseolus vulgaris in Tunisia, as well as by the reference strain Rhizobium tropici CIAT 899T. RESULTS The most NaCl-tolerant strain was A. tumefaciens 10c2, followed (in decreasing order) by R. tropici CIAT 899, R. leguminosarum bv. phaseoli 31c3, R. etli 12a3 and R. gallicum bv. phaseoli 8a3. 13C- and 1H-NMR analyses showed that all Rhizobium strains synthesized trehalose whereas A. tumefaciens 10c2 synthesized mannosucrose. Glutamate synthesis was also observed in R. tropici CIAT 899, R. leguminosarum bv. phaseoli 31c3 and A. tumefaciens 10c2. When added as a carbon source, mannitol was also accumulated by all strains. Accumulation of trehalose in R. tropici CIAT 899 and of mannosucrose in A. tumefaciens 10c2 was osmoregulated, suggesting their involvement in osmotolerance. The phylogenetic analysis of the otsA gene, encoding the trehalose-6-phosphate synthase, suggested the existence of lateral transfer events. In vivo 13C labeling experiments together with genomic analysis led us to propose the uptake and conversion pathways of different carbon sources into trehalose. Collaterally, the beta-1,2-cyclic glucan from R. tropici CIAT 899 was co-extracted with the cytoplasmic compatible solutes and its chemical structure was determined. CONCLUSIONS The soil bacteria analyzed in this work accumulated mainly disaccharides in response to NaCl stress. We could not find a direct correlation between the trehalose content of the rhizobial strains and their osmotolerance, suggesting that additional osmoadaptive mechanism should be operating in the most NaCl-tolerant strain R. tropici CIAT 899.
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10
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Torres LL, Salerno GL. A metabolic pathway leading to mannosylfructose biosynthesis in Agrobacterium tumefaciens uncovers a family of mannosyltransferases. Proc Natl Acad Sci U S A 2007; 104:14318-23. [PMID: 17728402 PMCID: PMC1964871 DOI: 10.1073/pnas.0706709104] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A metabolic pathway for biosynthesis of the nonreducing disaccharide mannosylfructose (beta-fructofuranosyl-alpha-mannopyranoside), an important osmolyte in Agrobacterium tumefaciens, was discovered. We have identified and functionally characterized two ORFs that correspond to genes (named mfpsA and mfppA) encoding the rare enzymes mannosylfructose-phosphate synthase and mannosylfructose-phosphate phosphatase, an associated phosphohydrolase. The mfpsA and mfppA genes are arranged in an operon structure, whose transcription is up-regulated by NaCl, resulting in the accumulation of mannosylfructose in the cells. Not only is the biosynthesis of mannosylfructose mechanistically similar to that of sucrose, but the corresponding genes for the biosynthesis of both disaccharides are also phylogenetic close relatives. Importantly, a protein phylogeny analysis indicated that mannosylfructose-phosphate synthase defines a unique group of mannosyltransferases.
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Affiliation(s)
- Leticia L. Torres
- Centro de Investigaciones Biológicas, Fundación para Investigaciones Biológicas Aplicadas, Casilla de Correo, 1348, 7600 Mar del Plata, Argentina
| | - Graciela L. Salerno
- Centro de Investigaciones Biológicas, Fundación para Investigaciones Biológicas Aplicadas, Casilla de Correo, 1348, 7600 Mar del Plata, Argentina
- *To whom correspondence should be addressed at:
Vieytes 3103, Casilla de Correo, 1348, 7600 Mar del Plata, Argentina. E-mail:
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11
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Essendoubi M, Brhada F, Eljamali JE, Filali-Maltouf A, Bonnassie S, Georgeault S, Blanco C, Jebbar M. Osmoadaptative responses in the rhizobia nodulating Acacia isolated from south-eastern Moroccan Sahara. Environ Microbiol 2007; 9:603-11. [PMID: 17298361 DOI: 10.1111/j.1462-2920.2006.01176.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Four strains of rhizobia nodulating Acacia were isolated from the Moroccan desert soil by trapping with seedlings of Acacia gummifera and Acacia raddiana, and were studied for their ability to tolerate high salinity and dryness conditions. The strains MDSMC 2, MDSMC 18 and MDSMC 50 were halotolerant (they tolerated up to 1 M NaCl) and they accumulated glutamate and mannosucrose. The synthesis of the latter solute, which is the major endogenous osmolyte, is partially repressed in the presence of glycine betaine. The strain MDSMC 34 was less halotolerant (growth inhibited by a concentration greater than 0.5 M NaCl), and accumulated trehalose (as the main endogenous osmolyte) and glutamate. Rhizobia from the Moroccan desert soil were highly resistant to desiccation and their tolerance to dryness was stimulated by osmotic pretreatment. Thus, the accumulation of mannosucrose or trehalose by desert rhizobia represents both an osmoadaptative response and a part of a desiccation tolerance mechanism.
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Affiliation(s)
- Mohammed Essendoubi
- Departement Osmorégulation chez les Bactéries, UMR-CNRS 6026, IFR 140, Université de Rennes 1, Campus de Beaulieu, Av. du Général Leclerc, 35042 Rennes, France
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12
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Gouffi K, Pica N, Pichereau V, Blanco C. Disaccharides as a new class of nonaccumulated osmoprotectants for Sinorhizobium meliloti. Appl Environ Microbiol 1999; 65:1491-500. [PMID: 10103242 PMCID: PMC91212 DOI: 10.1128/aem.65.4.1491-1500.1999] [Citation(s) in RCA: 68] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sucrose and ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidine carboxylic acid) are very unusual osmoprotectants for Sinorhizobium meliloti because these compounds, unlike other bacterial osmoprotectants, do not accumulate as cytosolic osmolytes in salt-stressed S. meliloti cells. Here, we show that, in fact, sucrose and ectoine belong to a new family of nonaccumulated sinorhizobial osmoprotectants which also comprises the following six disaccharides: trehalose, maltose, cellobiose, gentiobiose, turanose, and palatinose. Also, several of these disaccharides were very effective exogenous osmoprotectants for strains of Rhizobium leguminosarum biovars phaseoli and trifolii. Sucrose and trehalose are synthesized as endogenous osmolytes in various bacteria, but the other five disaccharides had never been implicated before in osmoregulation in any organism. All of the disaccharides that acted as powerful osmoprotectants in S. meliloti and R. leguminosarum also acted as very effective competitors of [14C]sucrose uptake in salt-stressed cultures of these bacteria. Conversely, disaccharides that were not osmoprotective for S. meliloti and R. leguminosarum did not inhibit sucrose uptake in these bacteria. Hence, disaccharide osmoprotectants apparently shared the same uptake routes in these bacteria. Natural-abundance 13C nuclear magnetic resonance spectroscopy and quantification of cytosolic solutes demonstrated that the novel disaccharide osmoprotectants were not accumulated to osmotically significant levels in salt-stressed S. meliloti cells; rather, these compounds, like sucrose and ectoine, were catabolized during early exponential growth, and contributed indirectly to enhance the cytosolic levels of two endogenously synthesized osmolytes, glutamate and the dipeptide N-acetylglutaminylglutamine amide. The ecological implication of the use of these disaccharides as osmoprotectants is discussed.
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Affiliation(s)
- K Gouffi
- Groupe Membranes et Osmorégulation, UPRES-A CNRS 6026, Université de Rennes 1, Campus de Beaulieu, F-35042 Rennes, France
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13
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da Costa MS, Santos H, Galinski EA. An overview of the role and diversity of compatible solutes in Bacteria and Archaea. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 1998; 61:117-53. [PMID: 9670799 DOI: 10.1007/bfb0102291] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The accumulation of compatible solutes is a prerequisite for the adaptation of microorganisms to osmotic stress imposed by salt or organic solutes. Two types of strategies exist to cope with high external solute concentrations; one strategy is found in the extremely halophilic Archaea of the family Halobacteriaceae and the Bacteria of the order Haloanaerobiales involving the accumulation of inorganic ions. The other strategy of osmoadaptation involves the accumulation of specific organic solutes and is found in the vast majority of microorganisms. The organic osmolytes range from sugars, polyols, amino acids and their respective derivatives, ectoines and betaines. The diversity of these organic solutes has increased in the past few years as more organisms, especially thermophilic and hyperthermophilic Bacteria and Archaea, have been examined. The term compatible solute can also be applied to solutes that protect macromolecules and cells against stresses such as high temperature, desiccation and freezing. The mechanisms by which compatible solutes protect enzymes, cell components and cells are still a long way from being thoroughly elucidated, but there is a growing interest in the utilization of these solutes to protect macromolecules and cells from heating, freezing and desiccation.
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Affiliation(s)
- M S da Costa
- Departamento de Bioquímica, Universidade de Coimbra, Portugal.
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14
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Desmarais D, Jablonski PE, Fedarko NS, Roberts MF. 2-Sulfotrehalose, a novel osmolyte in haloalkaliphilic archaea. J Bacteriol 1997; 179:3146-53. [PMID: 9150208 PMCID: PMC179091 DOI: 10.1128/jb.179.10.3146-3153.1997] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
A novel 1-->1 alpha-linked glucose disaccharide with sulfate at C-2 of one of the glucose moieties, 1-(2-O-sulfo-alpha-D-glucopyranosyl)-alpha-D-glycopyranose, was found to be the major organic solute accumulated by a Natronococcus sp. and several Natronobacterium species. The concentration of this novel disaccharide, termed sulfotrehalose, increased with increasing concentrations of external NaCl, behavior consistent with its identity as an osmolyte. A variety of noncharged disaccharides (trehalose, sucrose, cellobiose, and maltose) were added to the growth medium to see if they could suppress synthesis and accumulation of sulfotrehalose. Sucrose was the most effective in suppressing biosynthesis and accumulation of sulfotrehalose, with levels as low as 0.1 mM being able to significantly replace the novel charged osmolyte. Other common osmolytes (glycine betaine, glutamate, and proline) were not accumulated or used for osmotic balance in place of the sulfotrehalose by the halophilic archaeons.
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Affiliation(s)
- D Desmarais
- Merkert Chemistry Center, Boston College, Chestnut Hill, Massachusetts 02167, USA
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15
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Smith LT. Role of osmolytes in adaptation of osmotically stressed and chill-stressed Listeria monocytogenes grown in liquid media and on processed meat surfaces. Appl Environ Microbiol 1996; 62:3088-93. [PMID: 8795194 PMCID: PMC168099 DOI: 10.1128/aem.62.9.3088-3093.1996] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Listeria monocytogenes is a food-borne pathogen that is widely distributed in nature and is found in many kinds of fresh and processed foods. The pervasiveness of this organism is due, in part, to its ability to tolerate environments with elevated osmolarity and reduced temperatures. Previously, we showed that L. monocytogenes adapts to osmotic and chill stress by transporting the osmolyte glycine betaine from the environment and accumulating it intracellularly (R. Ko, L. T. Smith, and G. M. Smith, J. Bacteriol. 176:426-431, 1994). In the present study, the influence of various environmental conditions on the accumulation of glycine betaine and another osmolyte, carnitine, was investigated. Carnitine was shown to confer both chill and osmotic tolerance to the pathogen but was less effective than glycine betaine. The absolute amount of each osmolyte accumulated by the cell was dependent on the temperature, the osmolarity of the medium, and the phase of growth of the culture. L. monocytogenes also accumulated high levels of osmolytes when grown on a variety of processed meats at reduced temperatures. However, the contribution of carnitine to the total intracellular osmolyte concentration was much greater in samples grown on meat than in those grown in liquid media. While the amount of each osmolyte in meat was less than 1 nmol/mg (fresh weight), the overall levels of osmolytes in L. monocytogenes grown on meat were about the same as those in liquid samples, from about 200 to 1,000 nmol/mg of cell protein for each osmolyte. This finding suggests that the accumulation of osmolytes is as important in the survival of L. monocytogenes in meat as it is in liquid media.
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Affiliation(s)
- L T Smith
- Department of Agronomy and Range Science, University of California, Davis 95616, USA.
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Pocard JA, Smith LT, Smith GM, Le Rudulier D. A prominent role for glucosylglycerol in the adaptation of Pseudomonas mendocina SKB70 to osmotic stress. J Bacteriol 1994; 176:6877-84. [PMID: 7961447 PMCID: PMC197056 DOI: 10.1128/jb.176.22.6877-6884.1994] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The mechanism of osmoadaptation in a salt-tolerant (1.2 M NaCl) bacterial isolate identified as Pseudomonas mendocina (N. J. Palleroni, M. Doudoroff, R. Y. Stanier, R. E. Solanes, and R. Mandel, J. Gen. Microbiol. 60:215-231, 1970) was investigated. In response to osmotic stress, this species accumulated a number of compatible solutes, the intracellular levels of which depended on both the osmolarity and the ionic composition of the growth medium. Glucosylglycerol [alpha-D-glucopyranosyl-alpha-(1-->2)-glycerol], N-acetylglutaminylglutamine amide, and L-alpha-glutamate were the major compatible solutes accumulated via de novo biosynthesis. Trehalose was also accumulated, but only in cells grown in the presence of high concentrations of sulfate or phosphate ions. Glycine betaine was accumulated only when supplied exogenously to cells grown at high osmolarity, and its accumulation caused a significant depletion of the intracellular pools of glucosylglycerol and glutamate. Glucosylglycerol was also found to accumulate in the type strains of P. mendocina and P. pseudoalcaligenes. This is the first report demonstrating the pivotal role of glucosylglycerol in osmoadaptation in a nonphotosynthetic microorganism.
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Affiliation(s)
- J A Pocard
- Department of Agronomy and Range Science, University of California, Davis 95616
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Betaine attenuates glutamate-induced neurotoxicity in primary cultured brain cells. Arch Pharm Res 1994. [DOI: 10.1007/bf02974174] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Smith LT, Smith GM, D'Souza MR, Pocard JA, Rudulier DL, Madkour MA. Osmoregulation inRhizobium meliloti: Mechanism and control by other environmental signals. ACTA ACUST UNITED AC 1994. [DOI: 10.1002/jez.1402680214] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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