Biofilm formation is an effective survival strategy of plant-associated microorganisms in hostile environments, so the application of biofilm-forming and exopolysaccharide (EPS)-producing beneficial microbes to plants has received more attention in recent years. This study examined the ability of biofilm and EPS production of Bacillus subtilis and Bacillus thuringiensis strains under different NaCl concentrations (0, 50, 100, 200, and 400 mmol/L), pH values (5.5, 6.5, 7.5, and 8.5), and phosphate levels (0, 25, 50, and 100 mmol/L at 0 and 400 mmol/L NaCl). B. subtilis BS2 and B. thuringiensis BS6/BS7 strains significantly increased biofilm formation in a similar pattern to EPS production under salt stress. B. subtilis BS2/BS3 enhanced biofilm production at slightly acidic pH with a lower EPS production but the other strains formed considerably more amount of biofilm and EPS at alkaline pH. Interestingly, higher levels of phosphate substantially decreased biofilm and EPS production at 0 mmol/L NaCl but increased biofilm formation at 400 mmol/L salt concentration. Overall, contrary to phosphate, salt and pH differently influenced biofilm and EPS production by Bacillus strains. EPS production contributed to biofilm formation to some extent under all the conditions tested. Some Bacillus strains produced more abundant biofilm under salt and pH stress, indicating their potential to form in vivo biofilms in rhizosphere and on plants, particularly under unfavorable conditions.
- MeSH
- Bacillus subtilis fyziologie metabolismus účinky léků MeSH
- Bacillus thuringiensis fyziologie účinky léků MeSH
- bakteriální polysacharidy * metabolismus biosyntéza MeSH
- biofilmy * účinky léků růst a vývoj MeSH
- chlorid sodný * farmakologie metabolismus MeSH
- fosfáty * metabolismus farmakologie MeSH
- koncentrace vodíkových iontů MeSH
- Publikační typ
- časopisecké články MeSH
Fonticins are phage tail-like bacteriocins produced by the Gram-negative bacterium Pragia fontium from the family Budviciaceae. This bacterium produces contractile-type particles that adsorb on the surface of sensitive bacteria and penetrate the cell wall, probably during contraction, in a way similar to the type VI secretion system. We characterized the pore-forming activity of fonticins using both living cells and in vitro model membranes. Using a potassium leakage assay, we show that fonticins are able to permeabilize sensitive cells. On black lipid membranes, single-pore conductance is about 0.78 nS in 1 M NaCl and appears to be linearly dependent on the increasing molar strength of NaCl solution, which is a property of considerably large pores. In agreement with these findings, fonticins are not ion selective for Na+, K+, and Cl-. Polyethylene glycol 3350 (PEG 3350) molecules of about 3.5 nm in diameter can enter the fonticin pore lumen, whereas the larger molecules cannot pass the pore. The size of fonticin pores was confirmed by transmission electron microscopy. The terminal membrane-piercing complex of the fonticin tube probably creates a selective barrier restricting passage of macromolecules. IMPORTANCE Phage tail-like bacteriocins are now the subject of research as potent antibacterial agents due to their narrow host specificity and single-hit mode of action. In this work, we focused on the structure and mode of action of fonticins. According to some theories, related particles were initially adapted for passage of double-stranded DNA (dsDNA) molecules, but fonticins changed their function during the evolution; they are able to form large pores through the bacterial envelope of Gram-negative bacteria. As various pore-forming proteins are extensively used for nanopore sequencing and stochastic sensing, we decided to investigate the pore-forming properties of fonticin protein complexes on artificial lipid membranes. Our research revealed remarkable structural properties of these particles that may have a potential application as a nanodevice.
Vysoký příjem soli v potravě poškozuje nemocné ledviny řadou mechanismů. Jedním z nich může být acidifikační vliv soli. Poměr mezi obsahem natria a chloru je v extracelulární tekutině 1,4 : 1, zatímco v soli 1 : 1, a proto má požití soli acidifikační efekt. Podle Stewartovy-Fenclovy teorie acidobazické rovnováhy je rozdíl mezi náboji nesenými silnými kationty a silnými anionty (tzv. SID – strong ion difference; SID = (Na+ K+ Ca++ Mg++) – (Cl- + UA -) (UA- jsou ionty, které běžně nestanovujeme) jednou ze základních veličin, které rozhodují o koncetraci vodíkových iontů v extracelulární tekutině (ECT). Snížení SID acidifikuje. V souvislosti s příjmem soli můžeme SID zjednodušit na rozdíl [Na+ – Cl-]. Po požití soli se tento rozdíl v ECT sníží, a proto acidifikuje. Důsledkem je snížení [HCO3-]. Aby ledviny udržely fyziologickou hodnotu [Na+-Cl-], musí ve zvýšené míře syntetizovat NH4+ a HCO3- a tím uchovat fyziologický rozdíl [Na+-Cl-], a tudíž fyziologickou koncentraci [HCO3-] v krvi. To je spojeno se zvýšenou spotřebou kyslíku v ledvinách. „Sůl“ složená ze dvou třetin z NaCl a z jedné třetiny z NaHCO3 obsahuje oba ionty v přibližně stejném poměru, jako je tomu v ECT, a proto by neměla mít acidifikační efekt. Zdravé ledviny se s nadbytkem chloridů snadno vyrovnají. Domníváme se však, že při onemocněních ledvin by měl být bikarbonát podáván dříve, než se sníží pH, či dokonce [HCO3-]. Tím by se omezilo zatížení ledvin spojené se zvýšenou tvorbou bikarbonátu v důsledku solení.
A high salt intake is harmful to diseased kidneys by several mechanisms. The acidifying salt intake effect may be one of them. The ratio between sodium and chloride concentration is 1.4:1 in the extracellular fluid (ECF), while it is 1:1 in salt. According to the Stewart-Fencl theory, the ECF strong ion difference (SID = (Na++ K++Ca+++Mg++) – (Cl- + UA-); (UA- means routinely unidentified ions) is one of the basic variables determining the hydrogen ion concentration. The SID decrease causes acidemia and vice versa. In the context with salt intake, we can simplify the SID equation and replace it by the difference [Na+-Cl-]. In the ECF [Na+-Cl-] difference is diminished after the salt intake and contributes to acidemia, which is signalized by [HCO3-] decrease. To maintain a physiological [Na+-Cl-] in the ECF, the kidneys must raise the NH4+ and HCO3- synthesis from glutamate. This is associated with the increased kidney oxygen consumption. „Salt“ composed of the 2/3 of NaCl and 1/3 of NaHCO3 has [Na+-Cl-] difference in the approximately same level as it is in the ECF. Therefore this mixture does not have an acidifying effect. Healthy kidneys cope with the chloride excess after salt ingestion easily. However, we believe that in renal patients, apart from salt intake reduction, bicarbonate should be administered early in the course of disease, sooner than pH or even [HCO3-] are reduced. Thus, salt-elicited demand for increased bicarbonate synthesis would be suppressed early in the course of renal diseases.
- MeSH
- acidobazická rovnováha fyziologie MeSH
- chlorid sodný * metabolismus terapeutické užití MeSH
- fyziologie výživy fyziologie MeSH
- hydrogenuhličitan sodný metabolismus terapeutické užití MeSH
- lidé MeSH
- nemoci ledvin * dietoterapie MeSH
- poruchy acidobazické rovnováhy metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Crude oil extracted from oilfield reservoirs brings together hypersaline produced water. Failure in pipelines transporting this mixture causes contamination of the soil with oil and hypersaline water. Soil salinization is harmful to biological populations, impairing the biodegradation of contaminants. We simulated the contamination of a soil from an oilfield with produced water containing different concentrations of NaCl and crude oil, in order to evaluate the effect of salinity and hydrocarbon concentration on prokaryote community structure and biodegradation activity. Microcosms were incubated in CO2-measuring respirometer. After the incubation, residual aliphatic hydrocarbons were quantified and were performed 16S rRNA gene sequencing. An increase in CO2 emission and hydrocarbon biodegradation was observed with increasing oil concentration up to 100 g kg-1. Alpha diversity decreased in oil-contaminated soils with an increase in the relative abundance of Actinobacteria and reduction of Bacteroidetes with increasing oil concentration. In the NaCl-contaminated soils, alpha diversity, CO2 emission, and hydrocarbon biodegradation decreased with increasing NaCl concentration. There was an increase in the relative abundance of Firmicutes and Proteobacteria and a reduction of Actinobacteria with increasing salt concentration. Our results highlight the need to adopt specific bioremediation strategies in soils impacted by mixtures of crude oil and hypersaline produced water.
- MeSH
- Bacteria klasifikace genetika izolace a purifikace metabolismus MeSH
- chlorid sodný metabolismus MeSH
- mikrobiota * genetika MeSH
- oxid uhličitý metabolismus MeSH
- půda chemie MeSH
- půdní mikrobiologie * MeSH
- RNA ribozomální 16S genetika MeSH
- ropa metabolismus mikrobiologie MeSH
- ropná a plynová pole mikrobiologie MeSH
- salinita MeSH
- uhlovodíky metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
A systematic study on the lack of dissimilatory nitrate reductase (NAR) properties in Halomonas strains had been reported so far. The effects of different factors on Halomonas sp. B01 NAR activity were investigated. The salt tolerance of NAR was characterized. The denitrification process under high salt conditions was reported. Halomonas sp. B01 expressed membrane-bound NAR under induced culture by nitrate. The optimum pH of the enzyme reaction system was 8, and the optimum temperature was 30 °C. The mRNA expression abundance of narH in NAR encoding gene was highest in the 60 g/L NaCl inducing matrix. The NaCl concentration of optimum growth and induction of NAR were both 60 g/L. The ectoine added to the NAR vitro enzyme reaction system could maintain NAR activity under high NaCl concentration. In the range of 0-60 g/L NaCl, the NAR activity was stable at 17.7 (± 0.3) U/mg. The denitrification was performed by Halomonas sp. B01 at 60 g/L NaCl, and the denitrification rate reached 97.1% at 24 h. This study reveals for the first time the NAR properties of Halomonas strains, which provides a theoretical and technical basis for the nitrogen removal of high-salt nitrogenous wastewater using this strain.
- MeSH
- aminokyseliny diaminové metabolismus MeSH
- bakteriální proteiny genetika metabolismus MeSH
- buněčná membrána metabolismus MeSH
- chlorid sodný metabolismus MeSH
- denitrifikace MeSH
- dusičnany metabolismus MeSH
- Halomonas enzymologie genetika růst a vývoj metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- nitrátreduktasa genetika metabolismus MeSH
- regulace genové exprese u bakterií MeSH
- teplota MeSH
- tolerance k soli * MeSH
- Publikační typ
- časopisecké články MeSH
The role of microorganisms in litter degradation in arid and semi-arid zones, where soil and water salinization is one of the main factors limiting carbon turnover and decay, remains obscure. Heterostachys ritteriana (Amaranthaceae), a halophyte shrub growing in arid environments such as "Salinas Grandes" (Córdoba, Argentina), appears to be the main source of organic matter in the area. Little is known regarding the microorganisms associated with H. ritteriana, although they are a potential source of enzymes such as cellulolytic ones, which might be important in biotechnological fields such as bioethanol production using ionic liquids. In the present study, by studying the microbiota growing on H. ritteriana leaf litter in "Salinas Grandes," we isolated the cellulolytic fungus Fusarium equiseti LPSC 1166, which grew and degraded leaf litter under salt stress. The growth of this fungus was a function of the C substrate and the presence of NaCl. Although in vitro the fungus used both soluble and polymeric compounds from H. ritteriana litter and synthesized extracellular β-1,4 endoglucanases, its activity was reduced by 10% NaCl. Based on these results, F. equiseti LPSC 1166 can be described as a halotolerant cellulolytic fungus most probably playing a key role in the decay of H. ritteriana leaf litter in "Salinas Grandes."
- MeSH
- biodegradace MeSH
- celulosa metabolismus MeSH
- Chenopodiaceae mikrobiologie MeSH
- chlorid sodný metabolismus MeSH
- fungální proteiny genetika metabolismus MeSH
- Fusarium enzymologie genetika metabolismus MeSH
- glykosidhydrolasy genetika metabolismus MeSH
- listy rostlin mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
AIM: This study aimed at unprecedented physical and chemical evaluation of the 'green plastics' polyhydroxyalkanoates (PHAs), in an extremely halotolerant Halomonas elongata strain 2FF under high-salt concentration. METHODS AND RESULTS: The investigated bacterial strain was isolated from the surface water of the hypersaline Fără Fund Lake. The 16S rRNA gene sequence phylogeny and phenotypic analysis indicated that the isolate belonged to H. elongata. PHA inclusions were observed by Sudan Black B, Nile Red staining, and transmission electron microscopy during growth at high salinity (10%, w/v, NaCl) on 1% (w/v) d-glucose. The produced polymer was quantitatively and qualitatively assessed using crotonic acid assay, elemental analysis, Fourier transform infrared and Raman spectroscopies. Additionally, X-ray powder diffraction, 1 H-NMR spectroscopy, and differential scanning calorimetry were applied. The investigations showed that the intracellular polymer was polyhydroxybutyrate (PHB) of which the strain produced up to 40 wt% of total cell dry weight after 48 h. The analysis of phaC gene from the isolated H. elongata strain indicated that the encoded PHA synthase belongs to Class I PHA synthase family. CONCLUSIONS: Overall, our investigations pointed out that the halotolerant H. elongata strain 2FF was capable to produce significant amounts of PHB from d-glucose, and PHAs from various carbon substrates at high-salt concentrations. SIGNIFICANCE AND IMPACT OF THE STUDY: The tested strain showed the ability for significant production of natural, biodegradable polymers under nutrient limitation and hypersaline conditions suggesting its potentiality for further metabolic and molecular investigations towards enhanced biopolymer production. Additionally, this study reports on the unprecedented use of Raman and XPRD techniques to investigate PHAs of an extremely halotolerant bacterium, thus expanding the repertoire of physical methods to study green plastics derived from extremophilic microorganisms.
- MeSH
- biopolymery biosyntéza MeSH
- chlorid sodný metabolismus MeSH
- fylogeneze MeSH
- Halomonas genetika izolace a purifikace metabolismus MeSH
- jezera mikrobiologie MeSH
- polyhydroxyalkanoáty biosyntéza chemie MeSH
- RNA ribozomální 16S genetika MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Rumunsko MeSH
Candida dubliniensis was reported as a new species in 1995. This species is often misidentified as Candida albicans. The aims of this work were to determine the occurrence of C. dubliniensis in various clinical materials, to evaluate several ways to identify it and to examine the genetic variability of isolates. Among 7706 isolates originally identified as C. albicans, 237 were identified as C. dubliniensis (3.1%). Most of the C. dubliniensis isolates were obtained from the upper and lower respiratory tract (61.4 and 22.9%). Five phenotypic methods including latex agglutination were used (cultivation on CHROMagar Candida, on Staib agar, at 42 °C and in medium with 6.5% NaCl), but only cultivation on the medium with an increased concentration of NaCl and latex agglutination gave reliable results. Species-specific polymerase chain reaction was used as the confirmation method. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry provided less reliable results. In fact, 78.9% of C. dubliniensis isolates had scores above 1.7. However, the rest of them (21.1%) were also identified as C. dubliniensis even when the scores were lower than 1.7. Divergences among C. dubliniensis strains were evaluated by means of pulsed-field gel electrophoresis. Eighty-six selected C. dubliniensis isolates showed a 69.6% level of similarity. The results of this study expand the knowledge of the incidence, means of identification and genotypic divergence of C. dubliniensis isolates.
- MeSH
- Candida klasifikace genetika izolace a purifikace fyziologie MeSH
- chlorid sodný metabolismus MeSH
- genetická variace MeSH
- genotyp MeSH
- kandidóza mikrobiologie MeSH
- latex fixační testy MeSH
- lidé MeSH
- mikrobiologické techniky metody MeSH
- polymerázová řetězová reakce MeSH
- pulzní gelová elektroforéza MeSH
- spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
- teplota MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The yeast Nha1p Na(+), K(+)/H(+) antiporter has a house-keeping role in pH and cation homeostasis. It is also needed to alleviate excess Na(+) or K(+) from the cytoplasm under high external concentrations of these cations. Erv14p, a putative cargo receptor for transmembrane proteins is required for trafficking of Nha1p from the endoplasmic reticulum to the plasma membrane. Sensitivity to high Na(+) concentrations of the erv14 mutant associated to the intracellular mislocalization of Nha1p-GFP, together with a lower Na(+) efflux, indicate the involvement of this mutual association to accomplish the survival of the yeast cell upon sodium stress. This observation is supported by the protein-protein interaction between Erv14p and Nha1p detected by the mating-based Split Ubiquitin System and co-immunoprecipitation assays. Our results indicate that even though Erv14p interacts with Nha1p through the TMD, the C-terminal is important not only for the efficient delivery of Nha1p to the plasma membrane but also for its dimerization to accomplish its role in yeast salt tolerance.
- MeSH
- biologický transport MeSH
- chlorid sodný metabolismus farmakologie MeSH
- draslík metabolismus farmakologie MeSH
- interakční proteinové domény a motivy MeSH
- kationty jednomocné MeSH
- membránové proteiny chemie genetika metabolismus MeSH
- multimerizace proteinu MeSH
- Na(+)-H(+) antiport chemie genetika metabolismus MeSH
- proteiny přenášející kationty chemie genetika metabolismus MeSH
- protony * MeSH
- regulace genové exprese u hub * MeSH
- rekombinantní fúzní proteiny chemie genetika metabolismus MeSH
- Saccharomyces cerevisiae - proteiny chemie genetika metabolismus MeSH
- Saccharomyces cerevisiae účinky léků genetika metabolismus MeSH
- sekundární struktura proteinů MeSH
- tolerance k soli MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Water plays an important role in the transmission of Arcobacter spp. to animals and humans. The aim of this study was to isolate and characterize Arcobacter spp. from 115 different water samples (66 sewage, 25 rivers, 16 spring water, and 8 drinking water) in Izmir, Turkey. In total, 41 samples (35.7 %) were found positive for Arcobacter spp. by the genus-specific PCR. Arcobacter butzleri was detected in 39 out of 115 samples (33.9 %) including 24 sewage, 13 rivers, and 2 spring water. The remaining Arcobacter spp. (n = 2) isolates could not be identified by m-PCR and 16S rRNA gene sequencing. Based on the phenotypic characterization, most of the Arcobacter species (87.8 %) indicated weak catalase activity. In addition, there were differences in phenotypic patterns among isolated species during growth at 37 °C under microaerobic and aerobic conditions, in the presence of 2 % (39/41) and 3.5 % (32/41) NaCl and 0.04 % TTC (39/41) and on MacConkey agar (38/41). The results of this study indicated that environmental water samples are common sources for Arcobacter spp. Therefore, effective control measures should be taken to protect human health.
- MeSH
- aerobióza MeSH
- Arcobacter klasifikace genetika růst a vývoj izolace a purifikace MeSH
- chlorid sodný metabolismus MeSH
- DNA bakterií chemie genetika MeSH
- kultivační média chemie MeSH
- mikrobiologie vody * MeSH
- ribozomální DNA chemie genetika MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- techniky typizace bakterií MeSH
- teplota MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Turecko MeSH
