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Liang C, Jiang Q, Yu Y, Xu T, Sun H, Deng F, Yu X. Antibacterial Evaluation of Lithium-Loaded Nanofibrous Poly(L-Lactic Acid) Membranes Fabricated via an Electrospinning Strategy. Front Bioeng Biotechnol 2021; 9:676874. [PMID: 33996786 PMCID: PMC8116607 DOI: 10.3389/fbioe.2021.676874] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 04/07/2021] [Indexed: 12/03/2022] Open
Abstract
Lithium (Li) reportedly has anti-bacterial properties. Thus, it is an ideal option to modify barrier membranes used for guided bone regeneration to inhibit the bacterial adhesion. The aims of this study were to fabricate and characterize nanofibrous poly(L-lactic acid) (PLLA) membranes containing Li, and investigate their antibacterial effects on Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans in vitro. Li (5%Li, 10%Li, and 15%Li)-loaded nanofibrous PLLA membranes were fabricated using an electrospinning technique, and characterized via scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, a contact angle measuring device, and a universal testing machine. Sustained release of Li ions was measured over a 14-day period and biocompatibility of the Li-PLLA membranes was investigated. Evaluation of bacterial adhesion and antibacterial activity were conducted by bacterial colony counting, LIVE/DEAD staining and inhibition zone method using P.gingivalis and A.actinomycetemcomitans. Of the three Li-loaded membranes assessed, the 10%Li-PLLA membrane had the best mechanical properties and biocompatibility. Adhesion of both P.gingivalis and A.actinomycetemcomitans on Li-PLLA membranes was significantly lower than adhesion on pure PLLA membranes, particularly with regard to the 10%Li and 15%Li membranes. Significant antibacterial activity of Li-PLLA were also observed against according to the inhibition zone test. Given their better mechanical properties, biocompatibility, and antibacterial activity, PLLAs with 10%Li are a better choice for future clinical utilization. The pronounced antibacterial effects of Li-loaded PLLA membranes sets the stage for further application in guided bone regeneration.
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Affiliation(s)
- Chaoan Liang
- Guangdong Provincial Key Laboratory of Stomatology, Department of Oral Implantology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Qiming Jiang
- Guangdong Provincial Key Laboratory of Stomatology, Department of Oral Implantology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Yi Yu
- Guangdong Provincial Key Laboratory of Stomatology, Department of Oral Implantology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Tao Xu
- Biomanufacturing and Rapid Forming Technology Key Laboratory of Beijing, Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Department of Mechanical Engineering, Tsinghua University, Beijing, China
| | - Hanyu Sun
- Guangdong Provincial Key Laboratory of Stomatology, Department of Oral Implantology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Feilong Deng
- Guangdong Provincial Key Laboratory of Stomatology, Department of Oral Implantology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Xiaolin Yu
- Guangdong Provincial Key Laboratory of Stomatology, Department of Oral Implantology, Hospital of Stomatology, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, China
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Haferburg G, Gröning JAD, Schmidt N, Kummer NA, Erquicia JC, Schlömann M. Microbial diversity of the hypersaline and lithium-rich Salar de Uyuni, Bolivia. Microbiol Res 2017; 199:19-28. [PMID: 28454706 DOI: 10.1016/j.micres.2017.02.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 02/25/2017] [Indexed: 10/20/2022]
Abstract
Salar de Uyuni, situated in the Southwest of the Bolivian Altiplano, is the largest salt flat on Earth. Brines of this athalassohaline hypersaline environment are rich in lithium and boron. Due to the ever- increasing commodity demand, the industrial exploitation of brines for metal recovery from the world's biggest lithium reservoir is likely to increase substantially in the near future. Studies on the composition of halophilic microbial communities in brines of the salar have not been published yet. Here we report for the first time on the prokaryotic diversity of four brine habitats across the salar. The brine is characterized by salinity values between 132 and 177 PSU, slightly acidic to near-neutral pH and lithium and boron concentrations of up to 2.0 and 1.4g/L, respectively. Community analysis was performed after sequencing the V3-V4 region of the 16S rRNA genes employing the Illumina MiSeq technology. The mothur software package was used for sequence processing and data analysis. Metagenomic analysis revealed the occurrence of an exclusively archaeal community comprising 26 halobacterial genera including only recently identified genera like Halapricum, Halorubellus and Salinarchaeum. Despite the high diversity of the halobacteria-dominated community in sample P3 (Shannon-Weaver index H'=3.12 at 3% OTU cutoff) almost 40% of the Halobacteriaceae-assigned sequences could not be classified on the genus level under stringent filtering conditions. Even if the limited taxonomic resolution of the V3-V4 region for halobacteria is considered, it seems likely to discover new, hitherto undescribed genera of the family halobacteriaceae in this particular habitat of Salar de Uyuni in future.
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Affiliation(s)
- Götz Haferburg
- Interdisciplinary Ecological Center, Environmental Microbiology Group, TU Bergakademie Freiberg, Leipziger Strasse 29, 09599 Freiberg, Germany.
| | | | - Nadja Schmidt
- Institute of Hydrogeology and Environmental Geology, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 12, 09599 Freiberg, Germany
| | - Nicolai-Alexeji Kummer
- Institute of Hydrogeology and Environmental Geology, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 12, 09599 Freiberg, Germany
| | | | - Michael Schlömann
- Interdisciplinary Ecological Center, Environmental Microbiology Group, TU Bergakademie Freiberg, Leipziger Strasse 29, 09599 Freiberg, Germany
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Di Maiuta N, Schwarzentruber P, Dow CS. Enhancement of the antimicrobial performance of biocidal formulations used for the preservation of white mineral dispersions. Appl Microbiol Biotechnol 2010; 89:429-39. [PMID: 20878320 DOI: 10.1007/s00253-010-2884-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2010] [Revised: 09/03/2010] [Accepted: 09/07/2010] [Indexed: 01/29/2023]
Abstract
Biocides play an important role in the preservation of white mineral dispersions (WMD). Due to the occurrence of biocide-resistant bacteria and technical limitations in the use of biocides, new preservation strategies are required-like the enhancement of biocides by non-biocidal compounds. The aim of this study was to evaluate the biocide enhancement performance of lithium against various biocide-resistant bacteria in WMD. Subsequently, the minimal enhancing concentration (MEC) of lithium and the bioavailability of lithium in respect to the mode of introduction into WMD were investigated. The antimicrobial performance of biocidal formulations comprising isothiazolinones and formaldehyde releasers or isothiazolinones and glutaraldehyde has been evaluated against the related resistant bacterial spectrum in the presence of lithium. The MEC of lithium ranged from 1,350 to 1,500 ppm (based on the liquid phase weight of a WMD with 75% solids) for formaldehyde releasers and glutaraldehyde-based biocidal formulations, respectively. The biocide enhancing property of lithium was independent of whether lithium was introduced into WMD via a lithium-neutralised dispersant, added during the calcium carbonate grinding step, or dosed into the final product. Lithium is a non-biocidal compound which has been discovered to be a potent and universal biocide enhancer. Lithium boosts the biocidal activity of various biocides and provides a novel technique to overcome biocide resistance in WMD. Such a biocide enhancer represents a breakthrough that offers a potential tool to revolutionise the consumption of biocidal agents in the WMD producing industry.
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Affiliation(s)
- Nicola Di Maiuta
- Omya Development AG, R&D Microbiology, 4665 Oftringen, Switzerland.
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Dupont C, Augustin JC. Influence of stress on single-cell lag time and growth probability for Listeria monocytogenes in half Fraser broth. Appl Environ Microbiol 2009; 75:3069-76. [PMID: 19304822 PMCID: PMC2681640 DOI: 10.1128/aem.02864-08] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2008] [Accepted: 03/14/2009] [Indexed: 11/20/2022] Open
Abstract
The impacts of 12 common food industry stresses on the single-cell growth probability and single-cell lag time distribution of Listeria monocytogenes were determined in half Fraser broth, the primary enrichment broth of the International Organization for Standardization detection method. First, it was determined that the ability of a cell to multiply in half Fraser broth is conditioned by its history (the probability for a cell to multiply can be decreased to 0.05), meaning that, depending on the stress in question, the risk of false-negative samples can be very high. Second, it was established that when cells are injured, the single-cell lag times increase in mean and in variability and that this increase represents a true risk of not reaching the detection threshold of the method in the enrichment broth. No relationship was observed between the impact on single-cell lag times and that on growth probabilities. These results emphasize the importance of taking into account the physiological state of the cells when evaluating the performance of methods to detect pathogens in food.
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Affiliation(s)
- Claire Dupont
- Ecole Nationale Vétérinaire d'Alfort, Unité Microbiologie des Aliments-Sécurité et Qualité, 7 Avenue du Général de Gaulle, F-94704 Maisons-Alfort Cedex, France.
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Majerník A, Gottschalk G, Daniel R. Screening of environmental DNA libraries for the presence of genes conferring Na(+)(Li(+))/H(+) antiporter activity on Escherichia coli: characterization of the recovered genes and the corresponding gene products. J Bacteriol 2001; 183:6645-53. [PMID: 11673435 PMCID: PMC95496 DOI: 10.1128/jb.183.22.6645-6653.2001] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Environmental DNA libraries prepared from three different soils were screened for genes conferring Na(+)(Li(+))/H(+) antiporter activity on the antiporter-deficient Escherichia coli strain KNabc. The presence of those genes was verified on selective LK agar containing 7.5 mM LiCl. Two positive E. coli clones were obtained during the initial screening of 1,480,000 recombinant E. coli strains. Both clones harbored a plasmid (pAM1 and pAM3) that conferred a stable Li(+)-resistant phenotype. The insert of pAM2 (1,886 bp) derived from pAM1 contained a gene (1,185 bp) which encodes a novel Na(+)/H(+) antiporter belonging to the NhaA family. The insert of pAM3 harbored the DNA region of E. coli K-12 containing nhaA, nhaR, and gef. This region is flanked by highly conserved insertion elements. The sequence identity with E. coli decreased significantly outside of the insertion sequence elements, indicating that the unknown organism from which the insert of pAM3 was cloned is different from E. coli. The products of the antiporter genes located on pAM2 and pAM3 revealed functional homology to NhaA of E. coli and enabled the antiporter-deficient E. coli mutant to grow on solid media in the presence of up to 450 mM NaCl or 250 mM LiCl at pH 8.0. The Na(+)/H(+) antiporter activity in everted membrane vesicles that were derived from the E. coli strains KNabc/pAM2 and KNabc/pAM3 showed a substantial increase between pHs 7 and 8.5. The maximal activity was observed at pHs 8.3 and 8.6, respectively. The K(m) values of both antiporters for Na(+) were approximately 10-fold higher than the values for Li(+).
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Affiliation(s)
- A Majerník
- Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, 90028 Ivanka pri Dunaji, Slovak Republic
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Ikegami M, Kawano M, Takase K, Yamato I, Igarashi K, Kakinuma Y. Enterococcus hirae vacuolar ATPase is expressed in response to pH as well as sodium. FEBS Lett 1999; 454:67-70. [PMID: 10413097 DOI: 10.1016/s0014-5793(99)00776-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The Enterococcus hirae ntp operon encodes both a vacuolar ATPase, which transports Na+ as well as Li+, and the KtrII K+ transporter. A plasmid, in which the chloramphenicol acetyltransferase gene (CAT) was placed downstream of the ntp promoter, was introduced into a mutant totally defective in Na+ extrusion. The CAT activity of this transformant was increased preferentially by addition of NaCl, but not by LiCl, in the media or by elevating the medium pH, correlating well with the increase in amounts of the ATPase subunits observed by Western blotting. The physiological significance of these responses of the ntp promoter is discussed.
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Affiliation(s)
- M Ikegami
- Faculty of Pharmaceutical Sciences, Chiba University, Japan
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7
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Verkhovskaya ML, Verkhovsky MI, Wikström M. The respiration-driven active sodium transport system in E. coli does not function with lithium. FEBS Lett 1996; 388:217-8. [PMID: 8690090 DOI: 10.1016/0014-5793(96)00531-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Comparison of respiration-driven active transport of alkali cations from E. coli cells loaded with Na+ or Li+ showed that Li+ could not be expelled from the cells like Na+. K+ accumulation, which was fast in Na+-loaded cells, was strongly inhibited in Li+-loaded cells, despite high membrane potential and respiratory rate. When Li+-loaded cells were placed into medium containing Na+ instead of Li+, Li+/Na+ exchange took place initially, while K+ accumulation was delayed. Only after almost all inside Li+ was replaced by Na+ did active Na+ and K+ transport commence. These data confirm that it is a distinct active sodium transport system (AST) with Na+,K+/H+ antiporter activity, and not the Na+/H+ antiporters, that is responsible for active Na+ transport in E. coli [Verkhovskaya, M.L., Verkhovsky, M.I. and Wikstrom, M. (1996) Biochim. Biophys. Acta 1273, 207-216]. In contrast to the Na+/H+ antiporters, the AST system is inhibited by Li+.
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Affiliation(s)
- M L Verkhovskaya
- Helisinki Bioenegetics Group, Department of Medical Chemistry, Institute of Biomedical Sciences, University of Helsinki, Finland.
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Perkins J, Gadd GM. Interactions of Cs+ and other monovalent cations (Li+, Na+, K+, Rb+, NH4+) with K+-dependent pyruvate kinase and malate dehydrogenase from the yeasts Rhodotorula rubra and Saccharomyces cerevisiae. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s0953-7562(96)80142-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mendonca AF, Knabel SJ. A novel strictly anaerobic recovery and enrichment system incorporating lithium for detection of heat-injured Listeria monocytogenes in pasteurized milk containing background microflora. Appl Environ Microbiol 1994; 60:4001-8. [PMID: 7993088 PMCID: PMC201928 DOI: 10.1128/aem.60.11.4001-4008.1994] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Heat-injured cells of Listeria monocytogenes were recovered from heated raw milk containing noninjured Enterococcus faecium by combining a simple method for obtaining strict anaerobiosis with a novel enrichment broth, Penn State University broth (PSU broth). Strictly anaerobic conditions were rapidly achieved by adding 0.5 g of filter-sterilized cysteine per liter to PSU broth and then purging the preparation with N2 gas. Little resuscitation or growth occurred in strictly anaerobic PSU broth without lithium chloride because of overgrowth by E. faecium. The growth of E. faecium decreased dramatically with increasing LiCl concentration; LiCl concentrations of 8 and 10 g/liter were completely bacteriostatic. The mechanism of inhibition by LiCl appeared to involve competition with the divalent cations Ca2+ and Mg2+. Heat-injured L. monocytogenes consistently recovered and grew rapidly in strictly anaerobic PSU broth containing 4, 6, or 7 g of LiCl per liter. The use of strictly anaerobic PSU broth containing 7 g of LiCl per liter permitted detection of severely heat-injured L. monocytogenes in one simple recovery-enrichment step by eliminating oxygen toxicity and inhibiting the growth of background microflora, without preventing the resuscitation and subsequent growth of heat-injured L. monocytogenes. L. monocytogenes heated in raw milk at 62.8 degrees C for 10, 15, and 20 min could be consistently recovered from strictly anaerobic PSU broth enrichment cultures at 30 degrees C after 48, 96, and 144 h, respectively, and hence, use of PSU broth may result in better recovery of both injured and noninjured cells from foods than currently used U.S. Department of Agriculture and Food and Drug Administration preenrichment procedures.
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Affiliation(s)
- A F Mendonca
- Department of Food Science, Pennsylvania State University, University Park 16802
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10
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Padan E, Schuldiner S. Molecular physiology of Na+/H+ antiporters, key transporters in circulation of Na+ and H+ in cells. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1185:129-51. [PMID: 8167133 DOI: 10.1016/0005-2728(94)90204-6] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- E Padan
- Department of Microbial and Molecular Ecology, Hebrew University of Jerusalem, Israel
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11
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Abstract
In everted membrane vesicles of E. coli strain EP432/pGM42, which has only one Na+/H+ antiporter (NhaA), external CaCl2 inhibits dissipation of the respiration-dependent delta pH in response to the addition of NaCl at pH 7.5, and decreases equilibrium concentration of the intravesicular Na+. In the NhaA proteoliposomes, imposition of an artificial delta pH (acid inside) leads to the several-fold accumulation of calcium. The apparent Km for this delta pH-driven Ca2+ uptake at pH 8.5 is 2 mM, and the Vmax is 1.79 mumol/min/mg of protein. Dissipation of delta pH causes release of calcium from the vesicles. CaCl2 was found to inhibit the delta pH-driven Na+ uptake mediated by reconstituted NhaA, and vice versa. Further, heterological Ca2+/Na+ exchange has been demonstrated in proteoliposomes containing NhaA. Transmembrane electric potential difference proved to drive this process. All these data are consistent with the assumption that NhaA can also catalyze Ca2+/H+ exchange.
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Affiliation(s)
- P A Dibrov
- Division of Microbial and Molecular Ecology, Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Givat Ram, Israel
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12
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Padan E, Schuldiner S. Na+/H+ antiporters, molecular devices that couple the Na+ and H+ circulation in cells. J Bioenerg Biomembr 1993; 25:647-69. [PMID: 8144493 DOI: 10.1007/bf00770252] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Na+/H+ antiporters are universal devices involved in the Na+ and H+ circulation of both eukaryotes and prokaryotes, thus playing an essential role in the pH and Na+ homeostasis of cells. This review focuses on the major impact of the application of molecular biology tools in the study of the antiporters. These tools permit the verification of the role of the antiporters and provide insights into their unique biology. A novel signal transduction to Na+ involving nhaR, a positive regulator, controls the expression of nhaA in E. coli. A "pH sensor" regulates the activity of Na+/H+ antiporters, both in eukaryotes and prokaryotes. A most intricate signal transduction to pH involving phosphorylation steps controls the activity of nhel in higher mammals. The identification of Histidine 226 in the "pH sensor" of NhaA is a step forward towards the understanding of the pH regulation of these proteins.
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Affiliation(s)
- E Padan
- Division of Microbial and Molecular Ecology, Hebrew University of Jerusalem, Israel
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13
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Dibrov PA. The role of sodium ion transport in Escherichia coli energetics. BIOCHIMICA ET BIOPHYSICA ACTA 1991; 1056:209-24. [PMID: 1848102 DOI: 10.1016/s0005-2728(05)80052-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- P A Dibrov
- Department of Bioenergetics, A.N. Belozersky Laboratory of Molecular Biology and Bioorganic Chemistry, Moscow State University, U.S.S.R
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14
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Cox L, Dooley D, Beumer R. Effect of lithium chloride and other inhibitors on the growth ofListeria spp. Food Microbiol 1990. [DOI: 10.1016/0740-0020(90)90036-h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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15
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Yamato I, Ohsawa M, Anraku Y. Defective cation-coupling mutants of Escherichia coli Na+/proline symport carrier. Characterization and localization of mutations. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39820-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Wilson DM, Wilson TH. Cation specificity for sugar substrates of the melibiose carrier in Escherichia coli. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 904:191-200. [PMID: 3311166 DOI: 10.1016/0005-2736(87)90368-3] [Citation(s) in RCA: 85] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A study has been made of the sugar substrate specificities and the cation specificities of the melibiose transport system of Escherichia coli. The following beta-galactosides were found to be transported: lactose, L-arabinose-beta-D-galactoside, D-fructose-beta-D-galactoside, o- and p-nitrophenyl-beta-D-galactosides. These beta-galactosides were cotransported with Na+ but not with H+. The alpha-galactosides raffinose, melibiose and p-nitrophenyl-alpha-galactoside were transported with either H+ or Na+. Of the monosaccharides tested D-galactose could use either Na+ or H+ for cotransport whereas D-fucose, L-arabinose and D-galactosamine could use only Na+. The sugar specificity requirements for H+ cotransport are therefore more exacting than those for Na+ cotransport.
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Affiliation(s)
- D M Wilson
- Department of Physiology, Harvard Medical School, Boston, MA 02115
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17
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Ishikawa T, Hama H, Tsuda M, Tsuchiya T. Isolation and properties of a mutant of Escherichia coli possessing defective Na+/H+ antiporter. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)47585-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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18
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Shiota S, Yamane Y, Futai M, Tsuchiya T. Escherichia coli mutants possessing an Li+-resistant melibiose carrier. J Bacteriol 1985; 162:106-9. [PMID: 3884586 PMCID: PMC218961 DOI: 10.1128/jb.162.1.106-109.1985] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Escherichia coli K-12 strains in the absence of the lactose carrier grew on the disaccharide melibiose as the sole source of carbon. The presence of 0.1 mM Li+ in the medium strongly inhibited growth of such cells, and Li+-resistant mutants appeared after several days of incubation. These mutants showed altered cation coupling to melibiose transport via the melibiose carrier. Cotransport between H+ and melibiose was lost in the mutants, although Na+-melibiose cotransport was retained. We observed no Li+-melibiose cotransport. Therefore, these mutants represent a new type of cation-coupling mutants of the melibiose carrier.
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