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Abstract
Water is the cellular milieu, drives all biochemistry within Earth's biosphere and facilitates microbe-mediated decay processes. Instead of reviewing these topics, the current article focuses on the activities of water as a preservative-its capacity to maintain the long-term integrity and viability of microbial cells-and identifies the mechanisms by which this occurs. Water provides for, and maintains, cellular structures; buffers against thermodynamic extremes, at various scales; can mitigate events that are traumatic to the cell membrane, such as desiccation-rehydration, freeze-thawing and thermal shock; prevents microbial dehydration that can otherwise exacerbate oxidative damage; mitigates against biocidal factors (in some circumstances reducing ultraviolet radiation and diluting solute stressors or toxic substances); and is effective at electrostatic screening so prevents damage to the cell by the intense electrostatic fields of some ions. In addition, the water retained in desiccated cells (historically referred to as 'bound' water) plays key roles in biomacromolecular structures and their interactions even for fully hydrated cells. Assuming that the components of the cell membrane are chemically stable or at least repairable, and the environment is fairly constant, water molecules can apparently maintain membrane geometries over very long periods provided these configurations represent thermodynamically stable states. The spores and vegetative cells of many microbes survive longer in the presence of vapour-phase water (at moderate-to-high relative humidities) than under more-arid conditions. There are several mechanisms by which large bodies of water, when cooled during subzero weather conditions remain in a liquid state thus preventing potentially dangerous (freeze-thaw) transitions for their microbiome. Microbial life can be preserved in pure water, freshwater systems, seawater, brines, ice/permafrost, sugar-rich aqueous milieux and vapour-phase water according to laboratory-based studies carried out over periods of years to decades and some natural environments that have yielded cells that are apparently thousands, or even (for hypersaline fluid inclusions of mineralized NaCl) hundreds of millions, of years old. The term preservative has often been restricted to those substances used to extend the shelf life of foods (e.g. sodium benzoate, nitrites and sulphites) or those used to conserve dead organisms, such as ethanol or formaldehyde. For living microorganisms however, the ultimate preservative may actually be water. Implications of this role are discussed with reference to the ecology of halophiles, human pathogens and other microbes; food science; biotechnology; biosignatures for life and other aspects of astrobiology; and the large-scale release/reactivation of preserved microbes caused by global climate change.
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Affiliation(s)
- John E. Hallsworth
- Institute for Global Food SecuritySchool of Biological SciencesQueen’s University Belfast19 Chlorine GardensBelfastBT9 5DLUK
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Comparison of Preservation Methods of Staphylococcus aureus and Escherichia coli Bacteria. JOURNAL OF PURE AND APPLIED MICROBIOLOGY 2020. [DOI: 10.22207/jpam.14.3.58] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
One of the most important problems faced by microbiologists is to preserve bacterial isolates in the best state to study and further diagnosis. The current study aims to provide a summary of experimental results to maintain two species of bacteria alive after being stored by using some additives. This study found that the best temperature to preserve Staphylococcus aureus was -20°C for a year, while for Escherichia coli it was the same temperature except in using Glycerol (G) 100% and Food oil (FO) methods. The optimum method to preserve S. aureus was by using Normal Saline (NS), while Distilled Water (DW) was the optimum method to preserve E. coli at temperatures (4, 25 and -20)°C for a year, the phenotypic patterns for examining bacteria were maintained except in NS at 4°C for S. aureus after a year ago. Glycerol was used alone at concentrations (100, 50, 30 and 15)%, and another group used G+NS in the same volumes, good results were achieved when it used alone or with NS to preserve bacteria for six months at 4°C except for methods of G100% and (G100% + NS) for examining bacteria. FO has never been used as preservation liquid, it is successful to survive S. aureus at -20°C for a year, and when it was added to NS, E. coli survived for a year at three temperatures (4, 25 and -20)°C, while S. aureus didn’t survive for a year when FO+NS method used at room temperature. The precipitation method was used for bacterial suspension, then added the preserving liquid, but the results were not effective compared to the First method.
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3
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Morkus P, Zolfaghari M, Parrello D, Csordas M, Malikov M, Rose J, Choi KB, Filipe CDM, Latulippe DR. Optimization of microorganism preservation conditions for the development of an acute toxicity bioassay for biocides. CHEMOSPHERE 2019; 221:45-54. [PMID: 30634148 DOI: 10.1016/j.chemosphere.2018.12.182] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 12/22/2018] [Accepted: 12/24/2018] [Indexed: 06/09/2023]
Abstract
Biocides, also referred to as 'microbicides' or 'inhibitors', are widely used in industrial processes (e.g. utility water in cooling towers) to control and/or eliminate the growth of microorganisms. Because of their inherent toxicity, their presence in various sources (e.g. river sediments, potable water) can negatively affect ecosystems. Currently available biocide detection techniques are not suitable for 'point-of-use' applications since they are tedious, complicated, and often require experienced personnel to operate. To address this concern, we sought to develop a simple-to-use toxicity bioassay based on a model microorganism (E. coli) after short (<30 min) exposure to known biocides that can be stored at room temperature (preferably) or in the fridge. Based on recent work and our expertise in polymer-based preservation of biomolecules, we leveraged this knowledge to improve E. coli preservation for biocide detection purposes. A design-of-experiments strategy was used to evaluate 16 different preservation conditions from 5 process parameters (i.e. 25-1 fractional factorial). It was found that pullulan, a sugar-based polymer, improved E. coli culturability by an order of magnitude after three months of storage. Also, it was found that storing E. coli in the fridge in Milli-Q water was favorable for maintaining a high level of culturability. Finally, the toxicity of three common biocides (Cetyltrimethylammonium bromide (CTAB), ProClin™ 300, and Grotan® BK) was evaluated using a fluorescence-based assay across all 16 preservation conditions. The response of the preserved E. coli was biocide specific and at certain conditions did not vary during the entire three-month storage period.
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Affiliation(s)
- Patrick Morkus
- Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
| | - Mehdi Zolfaghari
- Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
| | - Damien Parrello
- Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
| | - Matthew Csordas
- Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
| | - Mikayil Malikov
- Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
| | - James Rose
- Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
| | - Kenneth Byungjun Choi
- Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
| | - Carlos D M Filipe
- Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada
| | - David R Latulippe
- Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, L8S 4L7, Canada.
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4
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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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Shahrokh Esfahani S, Emtiazi G, Shafiei R, Ghorbani N, Zarkesh Esfahani SH. Tolerance Induction of Temperature and Starvation with Tricalcium Phosphate on Preservation and Sporulation in Bacillus amyloliquefaciens Detected by Flow Cytometry. Curr Microbiol 2016; 73:366-373. [DOI: 10.1007/s00284-016-1066-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 04/13/2016] [Indexed: 11/24/2022]
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6
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Oxygen consumption rates of bacteria under nutrient-limited conditions. Appl Environ Microbiol 2013; 79:4921-31. [PMID: 23770901 DOI: 10.1128/aem.00756-13] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many environments on Earth experience nutrient limitation and as a result have nongrowing or very slowly growing bacterial populations. To better understand bacterial respiration under environmentally relevant conditions, the effect of nutrient limitation on respiration rates of heterotrophic bacteria was measured. The oxygen consumption and population density of batch cultures of Escherichia coli K-12, Shewanella oneidensis MR-1, and Marinobacter aquaeolei VT8 were tracked for up to 200 days. The oxygen consumption per CFU (QO2) declined by more than 2 orders of magnitude for all three strains as they transitioned from nutrient-abundant log-phase growth to the nutrient-limited early stationary phase. The large reduction in QO2 from growth to stationary phase suggests that nutrient availability is an important factor in considering environmental respiration rates. Following the death phase, during the long-term stationary phase (LTSP), QO2 values of the surviving population increased with time and more cells were respiring than formed colonies. Within the respiring population, a subpopulation of highly respiring cells increased in abundance with time. Apparently, as cells enter LTSP, there is a viable but not culturable population whose bulk community and per cell respiration rates are dynamic. This result has a bearing on how minimal energy requirements are met, especially in nutrient-limited environments. The minimal QO2 rates support the extension of Kleiber's law to the mass of a bacterium (100-fg range).
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Figge MJ, Robertson LA, Ast JC, Dunlap PV. Historical microbiology: revival and phylogenetic analysis of the luminous bacterial cultures of M. W. Beijerinck. FEMS Microbiol Ecol 2011; 78:463-72. [PMID: 22066815 DOI: 10.1111/j.1574-6941.2011.01177.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2011] [Revised: 07/21/2011] [Accepted: 07/24/2011] [Indexed: 11/29/2022] Open
Abstract
Luminous bacteria isolated by Martinus W. Beijerinck were sealed in glass ampoules in 1924 and 1925 and stored under the names Photobacterium phosphoreum and 'Photobacterium splendidum'. To determine if the stored cultures were viable and to assess their evolutionary relationship with currently recognized bacteria, portions of the ampoule contents were inoculated into culture medium. Growth and luminescence were evident after 13 days of incubation, indicating the presence of viable cells after more than 80 years of storage. The Beijerinck strains are apparently the oldest bacterial cultures to be revived from storage. Multi-locus sequence analysis, based on the 16S rRNA, gapA, gyrB, pyrH, recA, luxA, and luxB genes, revealed that the Beijerinck strains are distant from the type strains of P. phosphoreum, ATCC 11040(T), and Vibrio splendidus, ATCC 33125(T), and instead form an evolutionarily distinct clade of Vibrio. Newly isolated strains from coastal seawater in Norway, France, Uruguay, Mexico, and Japan grouped with the Beijerinck strains, indicating a global distribution for this new clade, designated as the beijerinckii clade. Strains of the beijerinckii clade exhibited little sequence variation for the seven genes and approximately 6300 nucleotides examined despite the geographic distances and the more than 80 years separating their isolation. Gram-negative bacteria therefore can survive for many decades in liquid storage, and in nature, they do not necessarily diverge rapidly over time.
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Affiliation(s)
- Marian J Figge
- The Netherlands Culture Collection of Bacteria, CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands
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8
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Boiardi J, Moreni N, Galar M. Survival and infectivity of aRhizobium melilotistrain maintained in water and buffer suspensions. ACTA ACUST UNITED AC 2008. [DOI: 10.1111/j.1365-2672.1988.tb01884.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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9
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Gomathy M, Thangaraju M, Gunasekaran S, Gopal NO. Sporulation and regeneration efficiency of phosphobacteria (Bacillus megaterium var phosphaticum). Indian J Microbiol 2007; 47:259-62. [PMID: 23100674 PMCID: PMC3450343 DOI: 10.1007/s12088-007-0047-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2007] [Revised: 06/25/2007] [Accepted: 06/30/2007] [Indexed: 12/01/2022] Open
Abstract
Sporulation in Bacillus megaterium var phosphaticum (PB - 1) was induced using modified nutrient media. This modified medium induced sporulation within 36 h. After spore induction the spores were kept under refrigerated (5°C) and room temperature (32°C) for five months and survival of spores was studied at 15 days intervals by plating them in nutrient agar medium. It was observed that there was not much variation in the storage temperature (5°C & 32°C). The spore cells of Bacillus megaterium var phosphaticum (PB - 1) were observed up to five months of storage under refrigerated (5°C) and room temperature (32°C). Regeneration of spore cells into vegetative cells was studied in tap water, rice gruel, nutrient broth, sterile lignite and sterile water at different concentrations of spore inoculum. The multiplication of sporulated Bacillus megaterium var phosphaticum culture was fast and reached its maximum (29.5 × 10(8) cfu ml(-1)) in nutrient broth containing 5 per cent inoculum level.
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Affiliation(s)
- M. Gomathy
- Department of Agricultural Microbiology, TNAU, Coimbatore, 641 003 India
| | - M. Thangaraju
- Department of Agricultural Microbiology, TNAU, Coimbatore, 641 003 India
| | - S. Gunasekaran
- Department of Agricultural Microbiology, TNAU, Coimbatore, 641 003 India
| | - N. O. Gopal
- Department of Agricultural Microbiology, TNAU, Coimbatore, 641 003 India
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10
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Liao CH, Shollenberger LM. Survivability and long-term preservation of bacteria in water and in phosphate-buffered saline. Lett Appl Microbiol 2003; 37:45-50. [PMID: 12803555 DOI: 10.1046/j.1472-765x.2003.01345.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS To evaluate the suitability of using sterile water and phosphate-buffered saline (PBS) for preservation of bacteria pathogenic to plants or humans. METHODS AND RESULTS The stationary-phase bacterial cells collected from rich agar media were transferred to 10 ml of sterile water or PBS (pH 7.2) containing KH2PO4, 15.44 microm; NaCl, 1.55 mm; Na2HPO4, 27.09 microm in a screw-cap tube. The tubes were sealed with parafilm membranes and stored in the dark and at room temperature. Almost all the bacteria tested (148 strains), including Pseudomonas fluorescens, P. viridiflava, Erwinia spp., Xanthomonas campestris, Cytophaga johnsonae, Salmonella spp., Yersinia enterocolitica, Escherichia coli O157:H7, Listeria monocytogenes and Staphylococcus aureus, survived in water for at least several months and up to 16 years. A vast majority of the Gram-negative bacteria tested survived equally well in water and in PBS for at least 30 weeks. However, the populations of two Gram-positive bacteria [G(+)], L. monocytogenes and Staph. aureus, declined more rapidly in water than in PBS. CONCLUSIONS Plant- and human-pathogenic bacteria can be preserved in pure water or PBS for several years. G(+) bacteria appear to survive better in PBS than in water. SIGNIFICANCE AND IMPACT OF THE STUDY The method described here is a simple and economical means for preservation of bacterial cultures, which is especially useful for laboratories not equipped with the lyophilizer or ultra-low freezer. Long-term survival of food-borne pathogens in water underlines the importance of water as a potential vehicle for transmitting the diseases.
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Affiliation(s)
- C-H Liao
- Food Safety Intervention Technologies Research Unit, US Department of Agriculture, Agricultural Research Service, Eastern Regional Research Center, Wyndmoor, PA 19038, USA.
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11
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Smeulders MJ, Keer J, Speight RA, Williams HD. Adaptation of Mycobacterium smegmatis to stationary phase. J Bacteriol 1999; 181:270-83. [PMID: 9864340 PMCID: PMC103559 DOI: 10.1128/jb.181.1.270-283.1999] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/1998] [Accepted: 10/28/1998] [Indexed: 11/20/2022] Open
Abstract
Mycobacterium tuberculosis can persist for many years within host lung tissue without causing clinical disease. Little is known about the state in which the bacilli survive, although it is frequently referred to as dormancy. Some evidence suggests that cells survive in nutrient-deprived stationary phase. Therefore, we are studying stationary-phase survival of Mycobacterium smegmatis as a model for mycobacterial persistence. M. smegmatis cultures could survive 650 days of either carbon, nitrogen, or phosphorus starvation. In carbon-limited medium, cells entered stationary phase before the carbon source (glycerol) had been completely depleted and glycerol uptake from the medium continued during the early stages of stationary phase. These results suggest that the cells are able to sense when the glycerol is approaching limiting concentrations and initiate a shutdown into stationary phase, which involves the uptake of the remaining glycerol from the medium. During early stationary phase, cells underwent reductive cell division and became more resistant to osmotic and acid stress and pool mRNA stabilized. Stationary-phase cells were also more resistant to oxidative stress, but this resistance was induced during late exponential phase in a cell-density-dependent manner. Upon recovery in fresh medium, stationary-phase cultures showed an immediate increase in protein synthesis irrespective of culture age. Colony morphology variants accumulated in stationary-phase cultures. A flat colony variant was seen in 75% of all long-term-stationary-phase cultures and frequently took over the whole population. Cryo scanning electron microscopy showed that the colony organization was different in flat colony strains, flat colonies appearing less well organized than wild-type colonies. Competition experiments with an exponential-phase-adapted wild-type strain showed that the flat strain had a competitive advantage in stationary phase, as well a providing evidence that growth and cell division occur in stationary-phase cultures of M. smegmatis. These results argue against stationary-phase M. smegmatis cultures entering a quiescent state akin to dormancy but support the idea that they are a dynamic population of cells.
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Affiliation(s)
- M J Smeulders
- Department of Biology, Imperial College of Science, Technology and Medicine, London SW7 2AZ, United Kingdom
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13
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Amy PS, Haldeman DL, Ringelberg D, Hall DH, Russell C. Comparison of Identification Systems for Classification of Bacteria Isolated from Water and Endolithic Habitats within the Deep Subsurface. Appl Environ Microbiol 1992; 58:3367-73. [PMID: 16348791 PMCID: PMC183105 DOI: 10.1128/aem.58.10.3367-3373.1992] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
One water and three rock samples were taken from a mined tunnel system, U12n, in Rainier Mesa at the Nevada Test Site. Endolithic microorganisms were cultured from ashfall tuff, which was crushed and made into slurries with a formulation of artificial pore water, on R2A agar plates. Microbial counts ranged from 10
2
to 10
4
viable cells per g (dry weight) of rock sampled. The cultured water sample yielded 10
2
viable cells per ml. Many of the isolates were very small (<1 μm) when viewed in the rock matrix and remained small even when cultured. Most were gram-negative rods. Individual isolates were profiled by API-NFT strip number, antibiotic and metal resistance patterns, and colony and cellular morphologies. Three identification systems, API-NFT strips, BIOLOG, and MIDI, were compared. Each system identified only a small percentage of the total isolates, and in only seven cases were the isolates identified the same way by more than one system. The same genus was identified in three of these cases, but different species were indicated. The genus
Pseudomonas
was the most commonly identified. The isolate profiles and the three identification systems demonstrated that water isolates were considerably different from endolithic isolates.
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Affiliation(s)
- P S Amy
- Department of Biological Sciences, University of Nevada, Las Vegas, Las Vegas, Nevada 89154; Desert Research Institute, Las Vegas, Nevada 89120 ; and Institute for Applied Microbiology, University of Tennessee, Knoxville, Tennessee 37932
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Cabral JP. Damage to the cytoplasmic membrane and cell death caused by dodine (dodecylguanidine monoacetate) in Pseudomonas syringae ATCC 12271. Antimicrob Agents Chemother 1991; 35:341-4. [PMID: 1902648 PMCID: PMC245002 DOI: 10.1128/aac.35.2.341] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Treatment of Pseudomonas syringae cells with low concentrations of the fungicide dodecylguanidine monoacetate (dodine) resulted in cell death and leakage of K+, UV-absorbing materials, and ribose-containing molecules. The results suggest that dodine causes gross and extensive damage to the cytoplasmic membrane, which is probably implicated in the death of cells.
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Affiliation(s)
- J P Cabral
- Instituto Nacional de Investigação Científica, Centro de Citologia Experimental da Universidade do Porto, Portugal
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Goodnow RA, Harrison MD, Morris JD, Sweeting KB, Laduca RJ. Fate of Ice Nucleation-Active
Pseudomonas syringae
Strains in Alpine Soils and Waters and in Synthetic Snow Samples. Appl Environ Microbiol 1990; 56:2223-7. [PMID: 16348241 PMCID: PMC184587 DOI: 10.1128/aem.56.7.2223-2227.1990] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The stability of the ice nucleation activity (INA) and viability of INA
Pseudomonas syringae
31a, used as an ice nucleator in the manufacture of synthetic snow, was determined in snow. The viability of
P. syringae
1-2b, a rifampin-resistant mutant selected from strain 31a to improve recovery from test samples, was determined in laboratory tests of three alpine soil and water samples from three different sources. Snow samples were exposed to environmental conditions or held in darkness at −20°C. Samples of soil and water were maintained in darkness at 0, 7.5, or 15°C. Parent strain 31a INA decreased significantly (>99.0%) in snow exposed to sunlight and freeze-thaw, while the INA of the cell population in snow held in darkness at −20°C remained essentially unchanged. No viable strain 31a was detected in snow exposed to the environment after 7 days, while the viability of strain 31a in snow held in darkness at −20°C decreased to <3% of the original inoculation at the test conclusion. Mutant strain 1-2b viability was undetectable or had decreased significantly 19 days postinoculation in soil samples held at 0 or 15°C. In contrast, 1-2b viability remained detectable at low levels for the duration of the test in soils held at 7.5°C. The 1-2b population demonstrated a significantly longer half-life in peatlike soil than in the loam soils tested. The rate of decrease in 1-2b viability was essentially the same in the three alpine water samples tested with respect to water temperature and sample location.
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Affiliation(s)
- R A Goodnow
- Genencor International, 1870 Winton Road, South, Rochester, New York 14618; Department of Plant Pathology and Weed Science, Colorado State University, Fort Collins, Colorado 80523 ; and Eastman Kodak Company, Rochester, New York 14650
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