Mounting evidence indicated the capability of various microorganisms in biosynthesis of exopolysaccharides (EPSs). A wide range of evidence extensively investigated the ability of bacterial species for EPS synthesis and their favorable effects, so little is known regarding yeast species. Many factors like composition of growth media and fermentation conditions are related to the structural and physical properties of EPSs. The EPS protects the producer yeast strain against extreme environment. Researchers proposed that yeast EPSs have priority over bacterial EPSs because of high yields of EPS biosynthesis and easy separation methods from growth media. Besides, they have drawn increasing attention due to their interesting biological activities, food, pharmaceutical, and cosmetics applications. Although a limited number of studies exist, this review aims to highlight the EPS structure and various applications of known yeast species in detail.
This is the first exhaustive report on the fungal community biodiversity in hypersaline water in România. A total of 27 fungal strains (19 molds and eight yeast) have been isolated from Lopătari hypersaline water, Buzau County. Based on classical investigation, these strains have been identified as belonging to the genera Aureobasidium, Alternaria, Aspergillus, Penicillium, and Fusarium. The molecular characterization of fungal isolates at species level was performed using PCR-RFLP analysis of the 5.8S-ITS region. PCR products were digested with different combinations of endonucleases. The most frequently isolated species were Aspergillus niger (14.81% of all isolates), A. versicolor, (14.81%) and Penicillium crustosum (14.81%). In addition, ribosomal restriction patterns which exhibited profiles specific to Aureobasidium pullulans were derived, and to discriminate between Aureobasidium isolates, the elongase-encoding gene (ELO) was chosen as a genetic marker followed by digestion with endonuclease HhaI. Five yeast isolates displayed restriction patterns corresponding to Aureobasidium melanogenum (18.52%) and three isolates to Aureobasidium pullulans (11.11%). In addition, the RFLP types of Aureobasidium pullulans varieties with HhaI are clearly distinguished and could be applied to assess the intraspecific variability.
- MeSH
- Ascomycota genetika izolace a purifikace metabolismus MeSH
- Aspergillus genetika izolace a purifikace metabolismus MeSH
- biodiverzita MeSH
- DNA fungální genetika MeSH
- fylogeneze MeSH
- houby klasifikace genetika izolace a purifikace MeSH
- kvasinky genetika izolace a purifikace metabolismus MeSH
- mikrobiologie vody * MeSH
- polymerázová řetězová reakce MeSH
- polymorfismus délky restrikčních fragmentů * MeSH
- řeky chemie mikrobiologie MeSH
- ribozomální DNA genetika MeSH
- sekvenční analýza DNA MeSH
- slané vody * MeSH
- tolerance k soli * MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Rumunsko MeSH
The natural behavior of mesenchymal stem cells (MSCs) and their exosomes in targeting tumors is a promising approach for curative therapy. Human tumor tropic mesenchymal stem cells (MSCs) isolated from various tissues and MSCs engineered to express the yeast cytosine deaminase::uracil phosphoribosyl transferase suicide fusion gene (yCD::UPRT-MSCs) released exosomes in conditional medium (CM). Exosomes from all tissue specific yCD::UPRT-MSCs contained mRNA of the suicide gene in the exosome's cargo. When the CM was applied to tumor cells, the exosomes were internalized by recipient tumor cells and in the presence of the prodrug 5-fluorocytosine (5-FC) effectively triggered dose-dependent tumor cell death by endocytosed exosomes via an intracellular conversion of the prodrug 5-FC to 5-fluorouracil. Exosomes were found to be responsible for the tumor inhibitory activity. The presence of microRNAs in exosomes produced from naive MSCs and from suicide gene transduced MSCs did not differ significantly. MicroRNAs from yCD::UPRT-MSCs were not associated with therapeutic effect. MSC suicide gene exosomes represent a new class of tumor cell targeting drug acting intracellular with curative potential.
- MeSH
- antimetabolity antitumorózní metabolismus farmakologie MeSH
- cytosindeaminasa genetika metabolismus MeSH
- exozómy genetika metabolismus MeSH
- flucytosin metabolismus MeSH
- fluorouracil metabolismus farmakologie MeSH
- fungální proteiny genetika metabolismus MeSH
- genetická terapie metody MeSH
- kvasinky genetika metabolismus MeSH
- lidé MeSH
- mezenchymální kmenové buňky metabolismus MeSH
- nádorové buněčné linie MeSH
- nádory prsu genetika metabolismus patologie MeSH
- pentosyltransferasy genetika metabolismus MeSH
- prekurzory léčiv metabolismus MeSH
- proliferace buněk účinky léků genetika MeSH
- transgeny sebevražedné genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The reserves of fossil-based fuels, which currently seem sufficient to meet the global demands, is inevitably on the verge of exhaustion. Contemporary raw material for alternate fuel like biodiesel is usually edible plant commodity oils, whose increasing public consumption rate raises the need of finding a non-edible and fungible alternate oil source. In this quest, single cell oils (SCO) from oleaginous yeasts and fungi can provide a sustainable alternate of not only functional but also valuable (polyunsaturated fatty acids (PUFA)-rich) lipids. Researches are been increasingly driven towards increasing the SCO yield in order to realize its commercial importance. However, bulk requirement of expensive synthetic carbon substrate, which inflates the overall SCO production cost, is the major limitation towards complete acceptance of this technology. Even though substrate cost minimization could make the SCO production profitable is uncertain, it is still essential to identify suitable cheap and abundant substrates in an attempt to potentially reduce the overall process economy. One of the most sought-after in-expensive carbon reservoirs, agro-industrial wastes, can be an attractive replacement to expensive synthetic carbon substrates in this regard. The present review assess these possibilities referring to the current experimental investigations on oleaginous yeasts, and fungi reported for conversion of agro-industrial feedstocks into triacylglycerols (TAGs) and PUFA-rich lipids. Multiple associated factors regulating lipid accumulation utilizing such substrates and impeding challenges has been analyzed. The review infers that production of bulk oil in combination to high-value fatty acids, co-production strategies for SCO and different microbial metabolites, and reutilization and value addition to spent wastes could possibly leverage the high operating costs and help in commencing a successful biorefinery. Rigorous research is nevertheless required whether it is PUFA-rich oil production (for competing with algal omega oils) or neutral bulk oil production (for overcoming yield limitations and managing process economy) to establish this potential source as future resource.
p73 is a member of the p53 protein family and has essential functions in several signaling pathways involved in development, differentiation, DNA damage responses and cancer. As a transcription factor, p73 achieves these functions by binding to consensus DNA sequences and p73 shares at least partial target DNA binding sequence specificity with p53. Transcriptional activation by p73 has been demonstrated for more than fifty p53 targets in yeast and/or human cancer cell lines. It has also been shown previously that p53 binding to DNA is strongly dependent on DNA topology and the presence of inverted repeats that can form DNA cruciforms, but whether p73 transcriptional activity has similar dependence has not been investigated. Therefore, we evaluated p73 binding to a set of p53-response elements with identical theoretical binding affinity in their linear state, but different probabilities to form extra helical structures. We show by a yeast-based assay that transactivation in vivo correlated more with the relative propensity of a response element to form cruciforms than to its expected in vitro DNA binding affinity. Structural features of p73 target sites are therefore likely to be an important determinant of its transactivation function.
- MeSH
- aktivace transkripce MeSH
- konformace nukleové kyseliny MeSH
- kvasinky genetika metabolismus MeSH
- lidé MeSH
- nádorový supresorový protein p53 metabolismus MeSH
- obrácené repetice * MeSH
- protein p73 chemie genetika metabolismus MeSH
- sekvence nukleotidů MeSH
- vazba proteinů MeSH
- vazebná místa * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Microorganisms do not live alone, but rather they communicate using diverse „languages“. In general, each bacterial species produces and responds to a unique autoinducer signal. Gram-negative bacteria use N-acylated homoserine lactones and gram-positive bacteria use oligopeptides as autoinducers. Function of autoinducer 2 is bacterial interspecies cell-to-cell communication. The structure and function of two main signaling molecules (farnesol and tyrosol) in the C. albicans quorum sensing (QS) system were also already described. Signaling molecules control the behavior of the whole population (especially virulence factors expression). That’s why QS systems represent a new therapeutic target, especially because of an increasing worldwide antibiotic resistance. Quorum sensing inhibitors are a promising direction in the treatment of infection caused by pathogenic micro¬organisms.
- Klíčová slova
- signální molekuly, N-acyl-homoserin lakton, inhibitory quorum sensing,
- MeSH
- antibakteriální látky MeSH
- antiinfekční látky MeSH
- Bacteria genetika klasifikace metabolismus patogenita MeSH
- bakteriální léková rezistence MeSH
- biofilmy MeSH
- Candida albicans patogenita MeSH
- česnek MeSH
- houby metabolismus patogenita MeSH
- kvasinky metabolismus patogenita MeSH
- léčivé rostliny chemie klasifikace MeSH
- mezibuněčná komunikace MeSH
- Pseudomonas aeruginosa patogenita MeSH
- quorum sensing * fyziologie genetika účinky léků MeSH
- signální transdukce MeSH
- Vibrio cholerae patogenita MeSH
- virulence genetika MeSH
- Publikační typ
- přehledy MeSH
Bark beetles (Curculionidae: Scolytinae) feed on the xylem and phloem of their host, which are composed of structural carbohydrates and organic compounds that are not easily degraded by the insects. Some of these compounds might be hydrolyzed by digestive enzymes produced by microbes present in the gut of these insects. In this study, we evaluated the enzymatic capacity of bacteria (Acinetobacter lwoffii, Arthrobacter sp., Pseudomonas putida, Pseudomonas azotoformans, and Rahnella sp.) and yeasts (Candida piceae, Candida oregonensis, Cyberlindnera americana, Zygoascus sp., and Rhodotorula mucilaginosa) isolated from the Dendroctonus rhizophagus gut to hydrolyze cellulose, xylan, pectin, starch, lipids, and esters. All isolates, with the exception of C. piceae, showed lipolytic activity. Furthermore, P. putida, P. azotoformans, C. americana, C. piceae, and R. mucilaginosa presented amylolytic activity. Esterase activity was shown by A. lwoffii, P. azotoformans, and Rahnella sp. Cellulolytic and xylanolytic activities were present only in Arthrobacter sp. and P. azotoformans. The pectinolytic activity was not recorded in any isolate. This is the first study to provide evidence on the capacity of microbes associated with the D. rhizophagus gut to hydrolyze specific substrates, which might cover part of the nutritional requirements for the development, fitness, and survival of these insects.
- MeSH
- Bacteria izolace a purifikace metabolismus MeSH
- biotransformace MeSH
- gastrointestinální trakt mikrobiologie MeSH
- kvasinky izolace a purifikace metabolismus MeSH
- nosatcovití mikrobiologie MeSH
- organické látky metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Tok1p is a highly specific yeast plasma membrane potassium channel with strong outward directionality. Its opening is induced by membrane depolarization. Although the biophysical properties of Tok1p are well-described, its potentially important physiological role is currently largely unexplored. To address this issue, we examined the Tok1p activity following chemically-induced depolarization by measuring changes of plasma membrane potential (ΔΨ) using the diS-C3(3) fluorescence assay in a Tok1p-expressing and a Tok1p-deficient strain. We report that Tok1p channel activity in response to chemical stress does not depend solely on the extent of depolarization, as might have been expected, but may also be negatively influenced by accompanying effects of the used compound. The stressors may interact with the plasma membrane or the channel itself, or cause cytosolic acidification. All of these effects may negatively influence the Tok1p channel opening. While ODDC-induced depolarization exhibits the cleanest Tok1p activation, restoring an astonishing 75% of lost ΔΨ, higher BAC concentrations reduce Tok1p activity, probably because of direct interactions with the channel and/or its lipid microenvironment. This is not only the first study of the physiological role of Tok1p in ΔΨ maintenance under chemical stress, but also the first estimate of the extent of depolarization the channel is able to counterbalance.
Oxidative stress induced by zero-valent iron nanoparticles (nZVIs) was used to improve lipid accumulation in various oleaginous and non-oleginous yeasts-Candida sp., Kluyveromyces polysporus, Rhodotorula glutinis, Saccharomyces cerevisiae, Torulospora delbrueckii, Trichosporon cutaneum, and Yarrowia lipolytica. The highest lipid yields occurred at 9-13 mg/L nZVIs. Gas chromatography-mass spectrometry was used for the quantitative and qualitative analysis of the fatty acids. It showed an increasing abundance of polyunsaturated fatty acids, especially essential linoleic acid, in the presence of nZVIs. Our results suggest that nZVIs can be used to improve not only lipid production by oleaginous microorganisms but also the nutritional value of biosynthesized unsaturated fatty acids.
- MeSH
- cytosol chemie MeSH
- kvasinky účinky léků metabolismus MeSH
- mastné kyseliny analýza MeSH
- metabolismus lipidů * MeSH
- nanočástice metabolismus MeSH
- oxidační stres * MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- železo metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
