A combination of two chromatographic and two enzymatic methods was used for the analysis of molecular species of lipids from Gram-positive bacteria of the genus Kocuria. Gram-positive bacteria contain a majority of branched fatty acids (FAs), especially iso- and/or anteiso-FAs. Two strains K. rhizophila were cultivated at three different temperatures (20, 28, and 37°C) and the majority phospholipid, i.e., the mixture of molecular species of phosphatidylglycerols (PGs) was separated by means of hydrophilic interaction liquid chromatography (HILIC). After enzymatic hydrolysis of PGs by phospholipase C and derivatization of the free OH group, the sn-1,2-diacyl-3-acetyl triacylglycerols (AcTAGs) were separated by reversed phase HPLC. Molecular species such as i-15:0/i-15:0/2:0, ai-15:0/ai-15:0/2:0, and 15:0/15:0/2:0 (straight chains) were identified by liquid chromatography-positive electrospray ionization mass spectrometry. The tandem mass spectra of both standards and natural compounds containing iso, anteiso and straight chain FAs with the same carbons were identical. Therefore, for identification of the ratio of two regioisomers, i.e. i-15:0/ai-15:0/2:0 vs. ai-15:0/i-15:0/2:0, they were cleavage by pancreatic lipase. The mixture of free fatty acids (FFAs) and 2-monoacylglycerols (2-MAGs) was obtained. After their separation by TLC and esterification and/or transesterification, the fatty acid methyl esters were quantified by GC-MS and thus the ratio of regioisomers was determined. It has been shown that the ratio of PG (containing as majority i-15: 0 / i-15: 0, i-15: 0 / ai-15: 0 and / or ai-15: 0 / i-15: 0 and ai-15: 0 / ai-15: 0 molecular species) significantly affected the membrane flow of bacterial cells cultured at different temperatures.
- MeSH
- chemické techniky analytické metody MeSH
- chromatografie kapalinová * MeSH
- diglyceridy chemie izolace a purifikace MeSH
- fosfolipidy chemie MeSH
- hmotnostní spektrometrie s elektrosprejovou ionizací * MeSH
- hydrofobní a hydrofilní interakce MeSH
- mastné kyseliny chemie MeSH
- Micrococcaceae chemie MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- vysokoúčinná kapalinová chromatografie MeSH
- Publikační typ
- časopisecké články MeSH
Bacteria have developed different intra- and inter-specific communication mechanisms that involve the production, release, and detection of signaling molecules, because these molecules serve as the autoinducers involved in "quorum sensing" systems. Other communication mechanisms employ volatile signaling molecules that regulate different bacterial processes. The Arthrobacter agilis strain UMCV2 is a plant growth promoting actinobacterium, which induces plant growth and inhibits phytopathogenic fungi by emitting the dimethylhexadecylamine (DMHDA). However, little is known about the effect of this volatile compound on A. agilis UMCV2 itself, as well as on other bacteria. By exposing A. agilis UMCV2 and bacteria of the genus Bacillus and Pseudomonas to different concentrations of DMHDA, this study showed the dose-dependent effects of DMHDA on A. agilis UMCV2 growth, cellular viability, swarming motility, and expression of marker genes of the flagellar apparatus of bacteria. DMHDA was found to also modulate swarming motility of Bacillus sp. ZAP018 and P. fluorescens UM270, but not that of P. aeruginosa PA01. These data indicate that DMHDA is involved in both intra- and inter-specific bacterial interaction.
- MeSH
- Arthrobacter účinky léků růst a vývoj MeSH
- Bacillus účinky léků růst a vývoj MeSH
- methylaminy farmakologie MeSH
- mikrobiální interakce účinky léků MeSH
- pohyb účinky léků MeSH
- Pseudomonas účinky léků růst a vývoj MeSH
- quorum sensing účinky léků MeSH
- těkavé organické sloučeniny farmakologie MeSH
- Publikační typ
- časopisecké články MeSH
In insects, external chemical defences, such as reflex bleeding, have been proved to be an efficient strategy against various predators. At the same time, significant costs of reflex bleeding can be expected because bled haemolymph is lost and all valuable components included have to be renewed. Interestingly, this issue has rarely been investigated for adult insects. In this study, we examined the immune and fitness costs of repeated reflex bleeding in adults of the invasive ladybird Harmonia axyridis, investigating several haemolymph parameters. Reflex bleeding induced twice a week for three weeks resulted in a significant reduction in haemocyte concentration, total protein content, and antimicrobial activity against Micrococcus luteus, and a marginally non-significant decrease in antimicrobial activity against Escherichia coli. Repeated reflex bleeding did not result in significant body mass reduction. Interestingly, resource limitation in the form of complete food absence did not significantly interact with reflex bleeding, even though starvation itself had a strong negative effect on all haemolymph parameters investigated and individual body mass. Daily reflex bleeding did not result in decreased fecundity of young ladybirds during the first 30 days of their adult life, but the start of ladybird reproduction was delayed by about two days. Moreover, ladybirds bleeding larger amounts of haemolymph started their reproduction significantly later. Overall, our results indicate that repeated reflex bleeding weakens a ladybird's immune system and can increase their susceptibility to pathogens, but a ladybird's reproductive potential remains almost unaffected, even by very intensive reflex bleeding.
- MeSH
- brouci imunologie fyziologie MeSH
- Escherichia coli patogenita MeSH
- hemolymfa MeSH
- imunitní systém * MeSH
- Micrococcus luteus patogenita MeSH
- rozmnožování MeSH
- tělesná hmotnost MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Bakterie rodu Kocuria patří mezi gram -pozitivní, nesporulující, převážně aerobní koky, které se vyskytují ve dvojicích, krátkých řetízkách či tetrádách. Dříve byl tento rod řazen mezi bakterie rodu Micrococcus, ale na základě fylogenetických a chemotaxonomických analýz byl začleněn do samostatného rodu Kocuria. Bakterie rodu Kocuria jsou morfologicky podobné bakteriím Staphylococcus a Micrococcus. S bakteriemi Staphylococcus jsou často zaměňovány při běžných fenotypových testech. V současné době je známo 28 druhů Kocuria, které se vyskytují v půdě, ve vodě, na kůži či sliznici lidí a zvířat. Některé druhy Kocuria mohou způsobovat zdravotní problémy, které jsou spojeny s dalšími nemocemi. Některé druhy se naopak mohou využít k produkci enzymů, biosurfaktantů či pigmentů v potravinářském, kosmetickém či farmaceutickém průmyslu. Jejich produkce extrémofilními kmeny rodu Kocuria má velký potenciál díky zvýšené stabilitě mikrobiálních produktů.
All of the recognize species of Kocuria are gram -positive coccoid, non -endospore -forming, aerobic, which are arranged in pairs, short chains or tetrads. The genus Kocuria was previously belongs to the family Micrococcaceae. On the basis of the phylogenetic and chemotaxonomic analyses, it was incorporated into a separate genus Kocuria. Kocuria are morphologically similar to bacteria Staphylococcus and Micrococcus. They are often confused with bacteria Staphylococcus by conventional phenotypic tests. At present, there are known 28 species of Kocuria, which occur in soil, water, skin or mucous membranes of humans and animals. Some species of Kocuria can cause healthy problems that are associated with other diseases. On the other hand some species can be used to produce enzymes, biosurfactants or pigments in the food, cosmetic or pharmaceutical industries. Their production of extremophilic strains of the genus Kocuria has great potential due to the increased stability of microbial products.
- MeSH
- grampozitivní bakteriální infekce MeSH
- lidé MeSH
- Micrococcaceae * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Avian eggs contend with omnipresent microorganisms entering the egg interior, where they affect embryo viability and hatchling phenotype. The incubation behaviour and deposition of egg white antimicrobial proteins (AMPs) vary highly across the avian altricial-precocial spectrum. Experimental evidence of how these alterations in avian reproductive strategies affect the antimicrobial properties of the precocial and altricial egg interior is lacking, however. Here, we tested the egg white antimicrobial activity in eggs of two representative model species, from each end of the avian altricial-precocial spectrum, against potentially pathogenic and beneficial probiotic microorganisms. Eggs were experimentally treated to mimic un-incubated eggs in the nest, partial incubation during the egg-laying period, the onset of full incubation and the increased deposition of two main egg white AMPs, lysozyme and ovotransferrin. We moreover assessed to what extent egg antimicrobial components, egg white pH and AMP concentrations varied as a result of different incubation patterns. Fully incubated precocial and altricial eggs decreased their antimicrobial activity against a potentially pathogenic microorganism, whereas partial incubation significantly enhanced the persistence of a beneficial probiotic microorganism in precocial eggs. These effects were most probably conditioned by temperature-dependent alterations in egg white pH and AMP concentrations. While lysozyme concentration and pH decreased in fully incubated precocial but not altricial eggs, egg white ovotransferrin increased along with the intensity of incubation in both precocial and altricial eggs. This study is the first to experimentally demonstrate that different incubation patterns may have selective antimicrobial potential mediated by species-specific effects on antimicrobial components in the egg white.
- MeSH
- antiinfekční látky farmakologie MeSH
- Bacillus subtilis účinky léků MeSH
- Columbidae fyziologie MeSH
- Coturnix fyziologie MeSH
- Micrococcus luteus účinky léků MeSH
- muramidasa farmakologie MeSH
- ovotransferin farmakologie MeSH
- ovum enzymologie fyziologie MeSH
- ptačí proteiny farmakologie MeSH
- rozmnožování * MeSH
- vaječný bílek chemie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Four bacterial isolates, which produced polyunsaturated fatty acids (PUFA), were isolated from water samples of radioactive springs collected from Jáchymov spa. Jáchymov (Sankt Joachimsthal) is a city in northwestern Bohemia, where Marie and Pierre Curie isolated radium in 1898 from the mineral uraninite. To date, four springs (Agricola, Behounek, C1, and Curie) have been used for spa purposes, that is for the treatment of nervous and rheumatic disorders by constantly produced radioactive gas radon (222 Rn) dissolved in the water. The radioactivity reaches 24 kBq/L. Using 16S rRNA gene sequence analysis, all four isolates were identified as members of the genus Kocuria, with two isolates designated 208 and 401 affiliated with Kocuria kristinae, while isolates 101 and 301 most likely with K. rhizophila. The content of fatty acids in polar lipids was determined by gas chromatography-mass spectrometry (GC-MS) and two PUFA, that is arachidonic and eicosapentaenoic, were identified. The position of double bonds was confirmed by GC-MS of 3-pyridylcarbinol (formerly picolinyl) esters. We assume that all four isolates of Kocuria produce PUFA to increase the stability of cell membranes, which may be impaired by the reaction of the reactive oxygen species. These can arise, for example, because of α radiation during 222 Rn decay.
The contact assay measuring the inhibition of Arthrobacter globiformis dehydrogenase activity as an endpoint to evaluate the toxicity of solid samples was tested in an international ring-test to validate its performance for ISO standardization (ISO/CD 18187). This work reports the results of the ring-test involving 9 laboratories from six countries. At least 8 valid data sets were obtained for each sample and more than three quarters of the participants attained the validity criteria defined in the standard. The coefficient of variation within (CVr) and between (CVR) laboratories was generally on average <15% and <30% for negative and positive controls, respectively. Regarding solid samples, the laboratories provided a similar ranking of the samples based on their toxicity, despite some variation in the LOEC values. The logarithmic within-lab standard deviation <0.50 for soils and <0.25 for wastes evidenced a good repeatability. The between-lab variability assessed by a CVR <30%, minimum-maximum factor <4 and a reproducibility standard deviation (SDR) <0.13 for a great part of the solid samples, confirmed the test reproducibility. Overall, this assay proved to be robust, sensitive and feasible for routine use towards the quality assessment of soils and wastes.
- MeSH
- Arthrobacter enzymologie MeSH
- biotest * MeSH
- dřevo analýza MeSH
- geologické sedimenty analýza MeSH
- hornictví MeSH
- hydrolasy metabolismus MeSH
- laboratoře MeSH
- látky znečišťující půdu analýza MeSH
- monitorování životního prostředí MeSH
- popel uhelný analýza MeSH
- průmyslový odpad analýza MeSH
- reprodukovatelnost výsledků MeSH
- sklo analýza MeSH
- těžké kovy analýza MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The formulation, characterization, and anticipated antibacterial properties of hemp seed oil and its emulsions were investigated. The oil obtained from the seeds of Cannabis sativa L. in refined and unrefined form was characterized using iodine, saponification, acid values, and gas chromatography, and was employed for the preparation of stable oil-in-water emulsions. The emulsions were prepared using pairs of non-ionic surfactants (Tween, Span). The effects of the emulsification method (spontaneous emulsification vs. high-intensity stirring), hydrophilic lipophilic balance (HLB), type and concentration of surfactant, and oil type on the size and distribution of the emulsion particles were investigated. It was found that the ability to form stable emulsions with small, initial particle sizes is primarily dependent on the given method of preparation and the HLB value. The most efficient method of emulsification that afforded the best emulsions with the smallest particles (151 ± 1 nm) comprised the high-energy method, and emulsions stable over the long-term were observed at HBL 9 with 10 wt % concentration of surfactants. Under high-intensity emulsification, refined and unrefined oils performed similarly. The oils as well as their emulsions were tested against the growth of selected bacteria using the disk diffusion and broth microdilution methods. The antibacterial effect of hemp seed oil was documented against Micrococcus luteus and Staphylococcus aureus subsp. aureus. The formulated emulsions did not exhibit the antibacterial activity that had been anticipated.
- MeSH
- antibakteriální látky chemie izolace a purifikace farmakologie MeSH
- Cannabis chemie MeSH
- emulze MeSH
- hydrofobní a hydrofilní interakce MeSH
- Micrococcus luteus účinky léků MeSH
- mikrobiální testy citlivosti MeSH
- oleje rostlin chemie izolace a purifikace farmakologie MeSH
- rostlinné extrakty chemie izolace a purifikace farmakologie MeSH
- semena rostlinná chemie MeSH
- Staphylococcus aureus účinky léků MeSH
- velikost částic MeSH
- Publikační typ
- časopisecké články MeSH
Myxobacteria, a group of antimicrobial producing bacteria, have been successfully cultured and characterized from ten soil samples collected from different parts of Slovakia. A total of 79 myxobacteria belonging to four genera (Myxococcus, Corallococcus, Sorangium, and Polyangium) were isolated based on aspects of their life cycle. Twenty-five of them were purified, fermented, and screened for antimicrobial activities against 11 test microorganisms. Results indicated that crude extracts showed more significant activities against Gram-positive than against Gram-negative bacteria or fungi. Based on a higher degree and broader range of antimicrobial production, the two most potential extracts (K9-5, V3-1) were selected for HPLC fractionation against Micrococcus luteus and Staphylococcus aureus and LC/MS analysis of potential antibiotic metabolites. The analysis resulted in the identification of polyketide-peptide antibiotics, namely corallopyronin A and B (K9-5) and myxalamid B and C (V3-1), which were responsible for important Gram-positive activity in the observed strains. A sequence similarity search through BLAST revealed that these strains showed the highest sequence similarity to Corallococcus coralloides (K9-5, NCBI accession number KX256198) and Myxococcus xanthus (V3-1, NCBI accession number KX256197). Although screening of myxobacteria is laborious, due to difficulties in isolating cultures, this research represented the first report covering the isolation and cultivation of this challenging bacterial group from Slovakian soils as well as the screening of their antimicrobial activity, cultural identification, and secondary metabolite identification.
- MeSH
- antibakteriální látky chemie metabolismus farmakologie MeSH
- fylogeneze MeSH
- Micrococcus luteus účinky léků MeSH
- Myxococcales chemie genetika izolace a purifikace metabolismus MeSH
- polyketidy chemie metabolismus farmakologie MeSH
- půdní mikrobiologie * MeSH
- Staphylococcus aureus účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
Pre-separation and pre-concentration of bacteria is an important step especially when they are uncultured and bacterial concentration in the matrix is low. This study describes a preparative method based on isoelectric focusing of colored microorganisms in a cellulose-based separation medium from a high conductivity matrix. The isoelectric points found for the examined cells were 1.8 for Micrococcus luteus, 3.5 for Dietzia sp., and 4.7 for Rhodotorula mucilaginosa using capillary isoelectric focusing. The final positions of the zones of colored microbial cells in the cellulose-bed are indicated by colored pI markers. Segments of the separation medium with cells were harvested by a spatula, simply purified using centrifugation and analyzed by capillary isoelectric focusing and matrix-assisted laser desorption/ionization time of flight mass spectrometry. The determined recovery ranged from 78% to 93%. The viability of the harvested cells was verified by their cultivation.
