Fungal metabolic carbon acquisition and its subsequent partitioning between biomass production and respiration, i.e. the carbon-use efficiency (CUE), are central parameters in biogeochemical modeling. However, current available techniques for estimating these parameters are all associated with practical and theoretical shortcomings, making assessments unreliable. Gene expression analyses hold the prospect of phenotype prediction by indirect means, providing new opportunities to obtain information about metabolic priorities. We cultured four different fungal isolates (Chalara longipes, Laccaria bicolor, Serpula lacrymans and Trichoderma harzianum) in liquid media with contrasting nitrogen availability and measured growth rates and respiration to calculate CUE. By relating gene expression markers to measured carbon fluxes, we identified genes coding for 1,3-β-glucan synthase and 2-oxoglutarate dehydrogenase as suitable markers for growth and respiration, respectively, capturing both intraspecific variation as well as within-strain variation dependent on growth medium. A transcript index based on these markers correlated significantly with differences in CUE between the fungal isolates. Our study paves the way for the use of these markers to assess differences in growth, respiration and CUE in natural fungal communities, using metatranscriptomic or the RT-qPCR approach.
- MeSH
- Ascomycota genetika metabolismus MeSH
- Basidiomycota genetika MeSH
- biologické markery * analýza MeSH
- fungální proteiny * genetika metabolismus MeSH
- houby * genetika metabolismus MeSH
- Hypocreales genetika metabolismus MeSH
- Laccaria genetika metabolismus MeSH
- transkriptom * MeSH
- Trichoderma genetika metabolismus MeSH
- uhlík * metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Numerous serotypes which belong to the genus Enterovirus (EV) show variability in their virulence and clinical manifestations. They are also known to undergo changes caused by mutations and recombination during their circulation in the environment and the population. Various EV serotypes are prevalent in groundwater, wastewater and surface waters. Our previous studies showed that oral infection induces pancreatitis depending on specific conditions, such as gravidity, in an outbred murine model. Our aim in the present study was to further explore the pancreatic histopathology in an outbred mouse model following oral infection with clinical isolates from a patient who had aseptic meningitis and an isolate from a treated-sewage sample recovered from the residential area of the patient. The isolates were identified as coxsackievirus B4 (CVB4) in tissue culture. The CVB4 sewage-isolate induced pancreatitis after oral infection. In contrast, pancreatitis was absent following infection with the clinical isolates. Comparison of polyprotein sequences showed that the treated-sewage strains differed from the patient's isolates by 9 and 11 amino acids. We conclude that the isolates of clinical and environmental origin differed in their pathogenic properties and showed genetic variation.
- MeSH
- coxsackie virózy * virologie MeSH
- enterovirus B lidský * patogenita fyziologie MeSH
- lidé MeSH
- myši MeSH
- odpadní vody * virologie MeSH
- pankreatitida * chemicky indukované virologie MeSH
- virulence MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Increasing antimicrobial resistance of nosocomial pathogens is becoming a serious threat to public health. To control the spread of this resistance, it is necessary to detect β-lactamase-producing organisms in the clinical setting. The aims of the study were to design a PCR assay for rapid detection of clinically encountered β-lactamase genes described in Enterobacteriaceae and Gram-negative non-fermenting bacteria. The functionality of proposed primers was verified using eight reference strains and 17 strains from our collection, which contained 29 different β-lactamase genes. PCR products of the test strains were confirmed by Sanger sequencing. Sequence analysis was performed using bioinformatics software Geneious. Overall, 67 pairs of primers for detecting 12 members of the class C β-lactamase family, 15 members of class A β-lactamases, six gene families of subclass B1, one member each of subclasses B2, B3 and class D β-lactamases were designed, of which 43 pairs were experimentally tested in vitro. All 29 β-lactamase genes, including 10 oxacillinase subgroups, were correctly identified by PCR. The proposed set of primers should be able to specifically detect 99.7% of analyzed β-lactamase subtypes and more than 79.8% of all described β-lactamase genes.
- MeSH
- Bacteria enzymologie genetika izolace a purifikace MeSH
- bakteriologické techniky * MeSH
- beta-laktamasy genetika metabolismus MeSH
- beta-laktamová rezistence genetika MeSH
- DNA bakterií genetika MeSH
- DNA primery MeSH
- lidé MeSH
- polymerázová řetězová reakce * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Inclusions in evaporitic minerals sometimes contain remnants of microorganisms or biomarkers, which can be considered as traces of life. Raman spectroscopy with resonance enhancement is one of the best analytical methods to search for such biomarkers in places of interest for astrobiology, including the surface and near subsurface of planet Mars. Portable Raman spectrometers are used as training tools for detection of biomarkers. Investigations of the limits and challenges of detecting biomolecules in crystals using Raman spectroscopy is important because natural occurrences often involve mineral assemblages as well as their fluid and solid inclusions. A portable Raman spectrometer with 532 nm excitation was used for detection of carotenoid biomarkers: salinixanthin of Salinibacter ruber (Bacteroidetes) and α-bacterioruberin of Halorubrum sodomense (Halobacteria) in laboratory-grown artificial inclusions in compound crystals of several chlorides and sulfates, simulating entrapment of microorganisms in evaporitic minerals. Crystals of halite (NaCl), sylvite (KCl), arcanite (K2SO4) and tschermigite ((NH4)Al(SO4)2·12H2O) were grown from synthetic solutions that contained microorganisms. A second crystalline layer of NaCl or K2SO4 was grown subsequently so that primary crystals containing microorganisms are considered as solid inclusions. A portable Raman spectrometer with resonance enabling excitation detected signals of both carotenoid pigments. Correct positions of diagnostic Raman bands corresponding to the specific carotenoids were recorded.
A specific technique of nuclear magnetic resonance (NMR) spectroscopy, filter-exchange spectroscopy (FEXSY), was employed to investigate water transport through the plasma membrane in intact yeast cells. This technique allows water transport to be monitored directly, thus avoiding the necessity to subject the cells to any rapid change in the external conditions, e.g. osmotic shock. We established a sample preparation protocol, a data analysis procedure and verified the applicability of FEXSY experiments. We recorded the exchange rates in the temperature range 10-40°C for Saccharomyces cerevisiae. The resulting activation energy of 29 kJ mol-1 supports the hypothesis that water exchange is facilitated by water channels-aquaporins. Furthermore, we measured for the first time water exchange rates in three other phylogenetically unrelated yeast species (Schizosaccharomyces pombe, Candida albicans and Zygosaccharomyces rouxii) and observed remarkably different water exchange rates between these species. Findings of our work contribute to a better understanding of as fundamental a cell process as the control of water transport through the plasma membrane.
- MeSH
- akvaporiny metabolismus MeSH
- biologický transport MeSH
- buněčná membrána metabolismus MeSH
- Candida albicans metabolismus MeSH
- kinetika MeSH
- magnetická rezonanční spektroskopie MeSH
- Schizosaccharomyces metabolismus MeSH
- teplota MeSH
- termodynamika MeSH
- voda metabolismus MeSH
- Zygosaccharomyces metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Infection with Toxoplasma gondii has usually been connected with consumption of improperly treated meat. However, contaminated water and products of plant origin have emerged as new sources of infection in the last few years. Here, 292 vegetable samples-carrot, cucumber and lettuce-obtained from nine farms in the Czech Republic were examined using triplex real time PCR targeting two specific T. gondii sequences. Irrigation water and water used for washing of vegetables were also included. Overall, a positivity rate of 9.6% was found in vegetables. The concentration varied between 1.31 × 100 and 9.00 × 102 oocysts/g of sample. A significant difference was found between the positivity of vegetables collected directly from fields and that of vegetables collected from farm storage rooms (4.4-8.6% vs 10-24.1%, respectively). All samples of irrigation water and water used to rinse vegetables were negative. Genotyping based on restriction fragment length polymorphism (RFLP) analysis using seven markers revealed the exclusive presence of genotype II.
- MeSH
- bezpečnost potravin MeSH
- farmy * MeSH
- genotyp MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- potravinářská parazitologie * MeSH
- Toxoplasma * klasifikace genetika izolace a purifikace MeSH
- zelenina parazitologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
We investigated the effect of Kluyveromyces lactis ERG6 gene deletion on plasma membrane function and showed increased susceptibility of mutant cells to salt stress, cationic drugs and weak organic acids. Contrary to Saccharomyces cerevisiae, Klerg6 mutant cells exhibited increased tolerance to tunicamycin. The content of cell wall polysacharides did not significantly vary between wild-type and mutant cells. Although the expression of the NAD+-dependent glycerol 3-phosphate dehydrogenase (KlGPD1) in the Klerg6 mutant cells was only half of that in the parental strain, it was induced in the presence of calcofluor white. Also, cells exposed to this drug accumulated glycerol. The absence of KlErg6p led to plasma membrane hyperpolarization but had no statistically significant influence on the plasma membrane fluidity. We propose that the phenotype of Klerg6 mutant cells to a large extent was a result of the reduced activity of specific plasma membrane proteins that require proper lipid composition for full activity.
- MeSH
- delece genu MeSH
- fungální proteiny genetika metabolismus MeSH
- fyziologická adaptace * MeSH
- kationické antimikrobiální peptidy metabolismus MeSH
- Kluyveromyces účinky léků enzymologie genetika fyziologie MeSH
- kyseliny karboxylové toxicita MeSH
- methyltransferasy genetika metabolismus MeSH
- osmotický tlak MeSH
- regulace genové exprese u hub * MeSH
- tolerance léku MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Pectinatella magnifica is a freshwater bryozoan, which has become a subject of scientific interest because of its invasive expansion worldwide. To obtain a comprehensive overview of its influence on environments, information on associated bacteria is needed. In this study, cultivable bacteria associated with P. magnifica were investigated. In total, 253 isolates were selected for preliminary identification by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and clustered based on repetitive extragenic palindromic-PCR profiles. Among these, 169 strains were selected and identified using 16S rRNA gene comparative analyses. The sequences were grouped into 76 phylotypes and affiliated with 67 species. The majority of isolated bacteria belonged to Gammaproteobacteria, followed by Betaproteobacteria, Firmicutes, Bacteroidetes and Actinobacteria. Most strains within the Betaproteobacteria were isolated exclusively from bryozoan colonies. Aeromonas was the genus predominantly isolated from both P. magnifica and the water samples. Based on 16S rDNA similarity values, 15 putative new species belonging to the genera Aeromonas, Aquitalea, Clostridium, Herbaspirillum, Chromobacterium, Chryseobacterium, Morganella, Paludibacterium, Pectobacterium, Rahnella, Rhodoferax and Serratia, and putative new genera belonging to families Clostridiaceae and Sporomusaceae were revealed. The majority of the detected bacteria were species widely distributed in the environments; nevertheless, a possible symbiotic association of two new putative species with P. magnifica cannot be excluded.
- MeSH
- Betaproteobacteria klasifikace genetika růst a vývoj izolace a purifikace MeSH
- Bryozoa mikrobiologie MeSH
- Firmicutes klasifikace genetika růst a vývoj izolace a purifikace MeSH
- fylogeneze MeSH
- Gammaproteobacteria klasifikace genetika růst a vývoj izolace a purifikace MeSH
- sladká voda mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
Dekkera bruxellensis is important for lambic beer fermentation but is considered a spoilage yeast in wine fermentation. We compared two D. bruxellensis strains isolated from wine and found that they differ in some basic properties, including osmotolerance. The genomes of both strains contain two highly similar copies of genes encoding putative glycerol-proton symporters from the STL family that are important for yeast osmotolerance. Cloning of the two DbSTL genes and their expression in suitable osmosensitive Saccharomyces cerevisiae mutants revealed that both identified genes encode functional glycerol uptake systems, but only DbStl2 has the capacity to improve the osmotolerance of S. cerevisiae cells.
- MeSH
- Dekkera genetika izolace a purifikace metabolismus fyziologie MeSH
- druhová specificita MeSH
- fungální proteiny genetika metabolismus MeSH
- genom bakteriální genetika MeSH
- glycerol metabolismus MeSH
- osmoregulace genetika MeSH
- protony MeSH
- rekombinantní proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae genetika MeSH
- symportéry genetika metabolismus MeSH
- testy genetické komplementace MeSH
- víno mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
Heterologous production of recombinant proteins is a cornerstone of microbiological and biochemical research as well as various biotechnological processes. Yields and quality of produced proteins have a tremendous impact on structural and enzymology studies, development of new biopharmaceuticals and establishing new biocatalytic processes. Majority of current protocols for recombinant protein expression in Escherichia coli exploit batch cultures with complex media, often providing low yields of the target protein due to oxygen transfer limitation, rapid depletion of carbon sources and pH changes during the cultivation. Recently introduced EnBase technology enables fed-batch-like cultivations in shake flasks with continuous glucose release from a soluble starch. In this study, we critically compare the yields of fourteen model enzymes in E. coli cultured in a novel semi-defined medium and in a complex medium. Significant improvements of the volumetric yields 2-31 times were observed for all tested enzymes expressed in enzymatic fed-batch-like cultures with no adverse impact on enzyme structure, stability or activity. Exceptional yields, higher than 1 g of protein per liter of culture, were obtained with six enzymes. We conclude that the novel semi-defined medium tested in this study provides a robust improvement of protein yields in shake flasks without investment into costly bioreactors.
