scholarly journals Effects of Temperature, Salinity, and Medium Composition on Compatible Solute Accumulation byThermococcus spp

1998 ◽  
Vol 64 (10) ◽  
pp. 3591-3598 ◽  
Author(s):  
Pedro Lamosa ◽  
Lígia O. Martins ◽  
Milton S. Da Costa ◽  
Helena Santos

ABSTRACT The effects of salinity and growth temperature on the accumulation of intracellular organic solutes were examined by nuclear magnetic resonance spectroscopy (NMR) in Thermococcus litoralis,Thermococcus celer, Thermococcus stetteri, andThermococcus zilligii (strain AN1). In addition, the effects of growth stage and composition of the medium were studied inT. litoralis. A novel compound identified as β-galactopyranosyl-5-hydroxylysine was detected in T. litoralis grown on peptone-containing medium. Besides this newly discovered compound, T. litoralis accumulated mannosylglycerate, aspartate, α-glutamate, di-myo-inositol-1,1′(3,3′)-phosphate, hydroxyproline, and trehalose. The hydroxyproline and β-galactopyranosyl-5-hydroxylysine were probably derived from peptone, while the trehalose was derived from yeast extract; none of these three compounds was detected in the other Thermococcus strains examined. Di-myo-inositol-1,1′(3,3′)-phosphate, aspartate, and mannosylglycerate were detected in T. celer and T. stetteri, and the latter organism also accumulated α-glutamate. The only nonmarine species studied, T. zilligii, accumulated very low levels of α-glutamate and aspartate. The levels of mannosylglycerate and aspartate increased in T. litoralis, T. celer, and T. stetteri in response to salt stress, while di-myo-inositol-1,1′(3,3′)-phosphate was the major intracellular solute at supraoptimal growth temperatures. The phase of growth had a strong influence on the types and levels of compatible solutes in T. litoralis; mannosylglycerate and aspartate were the major solutes during exponential growth, while di-myo-inositol-1,1′(3,3′)-phosphate was the predominant organic solute during the stationary phase of growth. This work revealed an unexpected ability of T. litoralis to scavenge suitable components from the medium and to use them as compatible solutes.

2002 ◽  
Vol 68 (2) ◽  
pp. 772-783 ◽  
Author(s):  
Anne U. Kuhlmann ◽  
Erhard Bremer

ABSTRACT By using natural-abundance 13C-nuclear magnetic resonance spectroscopy and high-performance liquid chromatography (HPLC) analysis we have investigated the types of compatible solutes that are synthesized de novo in a variety of Bacillus species under high-osmolality growth conditions. Five different patterns of compatible solute production were found among the 13 Bacillus species we studied. Bacillus subtilis, B. licheniformis, and B. megaterium produced proline; B. cereus, B. circulans, B. thuringiensis, Paenibacillus polymyxa, and Aneurinibacillus aneurinilyticus synthesized glutamate; B. alcalophilus, B. psychrophilus, and B. pasteurii synthesized ectoine; and Salibacillus (formerly Bacillus) salexigens produced both ectoine and hydroxyectoine, whereas Virgibacillus (formerly Bacillus) pantothenticus synthesized both ectoine and proline. Hence, the ability to produce the tetrahydropyrimidine ectoine under hyperosmotic growth conditions is widespread within the genus Bacillus and closely related taxa. To study ectoine biosynthesis within the group of Bacillus species in greater detail, we focused on B. pasteurii. We cloned and sequenced its ectoine biosynthetic genes (ectABC). The ectABC genes encode the diaminobutyric acid acetyltransferase (EctA), the diaminobutyric acid aminotransferase (EctB), and the ectoine synthase (EctC). Together these proteins constitute the ectoine biosynthetic pathway, and their heterologous expression in B. subtilis led to the production of ectoine. Northern blot analysis demonstrated that the ectABC genes are genetically organized as an operon whose expression is strongly enhanced when the osmolality of the growth medium is raised. Primer extension analysis allowed us to pinpoint the osmoregulated promoter of the B. pasteurii ectABC gene cluster. HPLC analysis of osmotically challenged B. pasteurii cells revealed that ectoine production within this bacterium is finely tuned and closely correlated with the osmolality of the growth medium. These observations together with the osmotic control of ectABC transcription suggest that the de novo synthesis of ectoine is an important facet in the cellular adaptation of B. pasteurii to high-osmolarity surroundings.


2006 ◽  
Vol 3 (2) ◽  
pp. 94 ◽  
Author(s):  
Hans Jörg Kunte

Environmental Context.Bacteria and Archaea have developed two basic mechanisms to cope with osmotic stress. The ‘salt-in-cytoplasm mechanism’ involves adjusting the salt concentration in the cytoplasm according to the environmental osmolarity and the ‘organic-osmolyte mechanism’ involves accumulating uncharged, highly water-soluble organic compounds in order to maintain an osmotic equilibrium with the surrounding medium. This highlight gives an overview of the osmoadaptation of prokaryotes employing the organic-osmolyte strategy and introduces a model explaining the fine-tuning of osmoregulatory osmolyte synthesis. Abstract.Bacteria and Archaea have developed two basic mechanisms to cope with osmotic stress, the salt-in-cytoplasm mechanism, and the organic-osmolyte mechanism. Organic osmolytes or so-called compatible solutes can be accumulated in molar concentration in the cytoplasm and allow for the adaptation of bacterial cells to varying salt concentrations. The biosynthetic pathways of compatible solutes and different compatible solute transport systems are described. A model for osmoregulatory compatible solute accumulation is introduced.


2002 ◽  
Vol 65 (6) ◽  
pp. 1008-1015 ◽  
Author(s):  
ODDUR VILHELMSSON ◽  
KAREN J. MILLER

The effects of different humectants (sodium chloride, sucrose, and glycerol) on the growth of and compatible solute (glycine betaine, proline, and carnitine) uptake by the osmotolerant foodborne pathogen Staphylococcus aureus were investigated. While growth in the presence of the impermeant humectants sodium chloride and sucrose induced the accumulation of proline and glycine betaine by cells, growth in the presence of the permeant humectant glycerol did not. When compatible solutes were omitted from low-water-activity media, growth was very poor in the presence of impermeant humectants. In contrast, the addition of compatible solutes had essentially no effect on growth when cells were grown in low-water-activity media containing glycerol as the humectant. Carnitine was found to accumulate to high intracellular levels in osmotically stressed cells when proline and glycine betaine were absent, making it a potentially important compatible solute for this organism.


Elem Sci Anth ◽  
2020 ◽  
Vol 8 ◽  
Author(s):  
Hannah M. Dawson ◽  
Katherine R. Heal ◽  
Angela K. Boysen ◽  
Laura T. Carlson ◽  
Anitra E. Ingalls ◽  
...  

Sea-ice algae are an important source of primary production in polar regions, yet we have limited understanding of their responses to the seasonal cycling of temperature and salinity. Using a targeted liquid chromatography-mass spectrometry-based metabolomics approach, we found that axenic cultures of the Antarctic sea-ice diatom, Nitzschia lecointei, displayed large differences in their metabolomes when grown in a matrix of conditions that included temperatures of –1 and 4°C, and salinities of 32 and 41, despite relatively small changes in growth rate. Temperature exerted a greater effect than salinity on cellular metabolite pool sizes, though the N- or S-containing compatible solutes, 2, 3-dihydroxypropane-1-sulfonate (DHPS), glycine betaine (GBT), dimethylsulfoniopropionate (DMSP), and proline responded strongly to both temperature and salinity, suggesting complexity in their control. We saw the largest (> 4-fold) response to salinity for proline. DHPS, a rarely studied but potential compatible solute, had the highest intracellular concentrations among all compatible solutes of ~85 mM. When comparing the culture findings to natural Arctic sea-ice diatom communities, we found extensive overlap in metabolite profiles, highlighting the relevance of culture-based studies to probe environmental questions. Large changes in sea-ice diatom metabolomes and compatible solutes over a seasonal cycle could be significant components of biogeochemical cycling within sea ice.


2000 ◽  
Vol 66 (11) ◽  
pp. 4696-4704 ◽  
Author(s):  
Katy R. Fraser ◽  
Duncan Harvie ◽  
Peter J. Coote ◽  
Conor P. O'Byrne

ABSTRACT We identified an operon in Listeria monocytogenes EGD with high levels of sequence similarity to the operons encoding the OpuC and OpuB compatible solute transporters from Bacillus subtilis, which are members of the ATP binding cassette (ABC) substrate binding protein-dependent transporter superfamily. The operon, designated opuC, consists of four genes which are predicted to encode an ATP binding protein (OpuCA), an extracellular substrate binding protein (OpuCC), and two membrane-associated proteins presumed to form the permease (OpuCB and OpuCD). The operon is preceded by a potential SigB-dependent promoter. An opuC-defective mutant was generated by the insertional inactivation of theopuCA gene. The mutant was impaired for growth at high osmolarity in brain heart infusion broth and failed to grow in a defined medium. Supplementation of the defined medium with peptone restored the growth of the mutant in this medium. The mutant was found to accumulate the compatible solutes glycine betaine and choline to same extent as the parent strain but was defective in the uptake ofl-carnitine. We conclude that the opuC operon in L. monocytogenes encodes an ABC compatible solute transporter which is capable of transporting l-carnitine and which plays an important role in osmoregulation in this pathogen.


1998 ◽  
Vol 29 (2) ◽  
pp. 397-407 ◽  
Author(s):  
Bert Poolman ◽  
Erwin Glaasker

Microbiology ◽  
2010 ◽  
Vol 156 (6) ◽  
pp. 1708-1718 ◽  
Author(s):  
Maud Flechard ◽  
Catherine Fontenelle ◽  
Carlos Blanco ◽  
Renan Goude ◽  
Gwennola Ermel ◽  
...  

Adaptation to osmotic stress can be achieved by the accumulation of compatible solutes that aid in turgor maintenance and macromolecule stabilization. The genetic regulation of solute accumulation is poorly understood, and has been described well at the molecular level only in enterobacteria. In this study, we show the importance of the alternative sigma factor RpoE2 in Sinorhizobium meliloti osmoadaptation. Construction and characterization of an S. meliloti rpoE2 mutant revealed compromised growth in hyperosmotic media. This defect was due to the lack of trehalose, a minor carbohydrate osmolyte normally produced in the initial stages of growth and in stationary phase. We demonstrate here that all three trehalose synthesis pathways are RpoE2 dependent, but only the OtsA pathway is important for osmoinducible trehalose synthesis. Furthermore, we confirm that the absence of RpoE2-dependent induction of otsA is the cause of the osmotic phenotype of the rpoE2 mutant. In conclusion, we have highlighted that, despite its low level, trehalose is a crucial compatible solute in S. meliloti, and the OtsA pathway induced by RpoE2 is needed for its accumulation under hyperosmotic conditions.


2003 ◽  
Vol 69 (4) ◽  
pp. 2015-2022 ◽  
Author(s):  
Katy R. Fraser ◽  
David Sue ◽  
Martin Wiedmann ◽  
Kathryn Boor ◽  
Conor P. O'Byrne

ABSTRACT The regulation of the compatible solute transport systems in Listeria monocytogenes by the stress-inducible sigma factor σB was investigated. Using wild-type strain 10403S and an otherwise isogenic strain carrying an in-frame deletion in sigB, we have examined the role of σB in regulating the ability of cells to utilize betaine and carnitine during growth under conditions of hyperosmotic stress. Cells lacking σB were defective for the utilization of carnitine but retained the ability to utilize betaine as an osmoprotectant. When compatible solute transport studies were performed, the initial rates of uptake of both betaine and carnitine were found to be reduced in the sigB mutant; carnitine transport was almost abolished, whereas betaine transport was reduced to approximately 50% of that of the parent strain. Analysis of the cytoplasmic pools of compatible solutes during balanced growth revealed that both carnitine and betaine steady-state pools were reduced in the sigB mutant. Transcriptional reporter fusions to the opuC (which encodes an ABC carnitine transporter) and betL (which encodes an a secondary betaine transporter) operons were generated by using a promoterless copy of the gus gene from Escherichia coli. Measurement of β-glucuronidase activities directed by opuC-gus and betL-gus revealed that transcription of opuC is largely σB dependent, consistent with the existence of a potential σB consensus promoter motif upstream from opuCA. The transcription of betL was found to be sigB independent. Reverse transcriptase PCR experiments confirmed these data and indicated that the transcription of all three known compatible solute uptake systems (opuC, betL, and gbu), as well as a gene that is predicted to encode a compatible solute transporter subunit (lmo1421) is induced in response to elevated osmolarity. The osmotic induction of opuCA and lmo1421 was found to be strongly σB dependent. Together these observations suggest that σB plays a major role in the regulation of carnitine utilization by L. monocytogenes but is not essential for betaine utilization by this pathogen.


1988 ◽  
Vol 34 (5) ◽  
pp. 605-612 ◽  
Author(s):  
Yves Bellinger ◽  
François Larher

Glycerol, arabitol and trehalose were the principle solutes detected in cellular extracts of Hansenula anomala, using natural-abundance 13C nuclear magnetic resonance spectroscopy. Only the two polyols accumulated in response to increased salinity, glycerol increase being far greater. Arabitol content also increased with culture age, independently of the presence or absence of salt and in line with the evolution of trehalose content. Glycerol retention potential was 15 times greater for Hansenula than for Saccharomyces cerevisiae. The former displayed the specific property of increasing this capacity in high salt concentrations. Under such conditions its growth was associated with a limited increase in glucose consumption per unit biomass, relative to S. cerevisiae, the salt-sensitive reference yeast. In addition, a polysaccharide, the chemical nature of which was not further characterized, was detected exclusively in the external medium of Hansenula growing in the presence of salt.


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