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FEMS Immunology and Medical Microbiology Sep 1998A strategy for the prevention and control of candidiasis, pneumocystosis, and tuberculosis, based on the idiotypic network of the yeast killer effect has been envisaged.... (Review)
Review
A strategy for the prevention and control of candidiasis, pneumocystosis, and tuberculosis, based on the idiotypic network of the yeast killer effect has been envisaged. Anti-idiotypic antibodies representing the internal image of a candidacidal, pneumocysticidal, and mycobactericidal killer toxin from Pichia anomala and idiotypes of killer toxin-neutralizing monoclonal antibodies mimicking the specific cell wall receptor of sensitive microorganisms might provide a unique approach for engineering innovative antibiotics and vaccines active against taxonomically unrelated pathogenic microorganisms. The rationale of the strategy relies on a phenomenon of microbial competition which has been mutated by the immune system in the response to natural infections.
Topics: Animals; Cloning, Molecular; Drug Carriers; Humans; Infection Control; Killer Factors, Yeast; Lactobacillus; Mycobacterium; Mycotoxins; Pichia; Recombinant Fusion Proteins; Transgenes
PubMed: 9792074
DOI: 10.1111/j.1574-695X.1998.tb01200.x -
Brazilian Journal of Microbiology :... Apr 2011A yeast strain designated as Y-1 was isolated and characterized from wine yeast ("Jiuqu"). Based on the morphological and biochemical results, along with the rDNA...
A yeast strain designated as Y-1 was isolated and characterized from wine yeast ("Jiuqu"). Based on the morphological and biochemical results, along with the rDNA internal transcribed spacer region (ITS), Y-1 was identified to be a Pichia anomala strain. Y-1 is an ethanol-tolerant strain, enduring ethanol concentrations of up to 14 %. Y-1 growth medium conditions were optimized, results showing good growth in medium with pH ranges from 3.5-6.5, temperature ranges from 25-30 °C, and inoculums range of 8 %-12 %, while optimum growth conditions were reached at a temperature of 30 °C, pH 5.0, and inoculums of 10 %. Furthermore, when the alkaline hydrolyzed Shatian pummelo peel solutions were inoculated with 10 % Y-1 and fermented at 30 °C for 6 d, 4.7 % pure ethanol (w/w) was produced, as evidenced by gas chromatography analysis. Our present study shows potential for the Y-1 strain to be a promising candidate for bioethanol production.
PubMed: 24031678
DOI: 10.1590/S1517-838220110002000031 -
Molecules (Basel, Switzerland) Mar 2021Olive mill wastewater (OMW) contains valuable and interesting bioactive compounds, among which is hydroxytyrosol, which is characterized by a remarkable antioxidant...
Olive mill wastewater (OMW) contains valuable and interesting bioactive compounds, among which is hydroxytyrosol, which is characterized by a remarkable antioxidant activity. Due to the health claims related to olive polyphenols, the aim of this study was to obtain an extract from OMW with an increased level of hydroxytyrosol by means of microbial enzymatic activity. For this purpose, four commercial adsorbent resins were selected and tested. The beta-glucosidase and esterase activity of strains of , and were also investigated and compared to those of a commercial enzyme and an strain. The strain showed the best enzymatic performances. The SP207 resin showed the best efficiency in selective recovery of hydroxytyrosol, tyrosol, oleuropein, and total phenols. The bioconversion test of the OMW extract was assessed by using both culture broths and pellets of the tested strains. The results demonstrated that the pellets of and were the most effective in hydroxytyrosol increasing in phenolic extract. The interesting results suggest the possibility to study new formulations of OMW phenolic extracts with multifunctional microorganisms.
Topics: Fungi; Lactobacillaceae; Olea; Phenols; Plant Extracts; Probiotics; Waste Disposal, Fluid; beta-Glucosidase
PubMed: 33808362
DOI: 10.3390/molecules26071944 -
Mycology 2021Non-conventional wine yeasts are extensively studied as promising producers of hydrolytic enzymes and as potential starter cultures in winemaking due to their ability to...
Non-conventional wine yeasts are extensively studied as promising producers of hydrolytic enzymes and as potential starter cultures in winemaking due to their ability to improve organoleptic properties of wine. Thirty-six yeast strains of enological and brewery origin from the Ukrainian Collection of Microorganisms belonging to , and genera have been screened for the production of extracellular hydrolases, stress tolerance, fermentative activity, and other traits of enological interest. This study revealed the high incidence of lipolytic, proteolytic, and β-glucosidase activities among the yeasts, while no pectinase activity was detected. Esterase, cellulase and glucanase activities were found in a small proportion of yeasts (8.33-16.66%). Several , and strains demonstrated a wide range of hydrolytic activities. High tolerance to stress factors (ethanol, osmotic, and oxidative stress) present during alcoholic fermentation was detected in and strains. Fermentative activity of several yeast strains was evaluated in microfermentations in a model semi-synthetic medium. Strain UCM Y-216 was selected as the most promising culture for winemaking due to its hydrolytic activities, tolerance to stress factors and other valuable metabolic traits. This study represents the first step for selecting a non-conventional yeast strain of enological origin as a potential co-culture for winemaking.
PubMed: 34552811
DOI: 10.1080/21501203.2020.1837272 -
Frontiers in Microbiology 2020French PDO Nyons black table olives are produced according to a traditional slow spontaneous fermentation in brine. The manufacture and unique sensorial properties of...
French PDO Nyons black table olives are produced according to a traditional slow spontaneous fermentation in brine. The manufacture and unique sensorial properties of these olives thus only rely on the autochthonous complex microbiota. This study aimed at unraveling the microbial communities and dynamics of Nyons olives during a 1.5-year-long spontaneous fermentation to determine the main microbial drivers and link microbial species to key metabolites. Fermentations were monitored at a local producer plant at regular time intervals for two harvests and two olive types (organically and conventionally grown) using culture-dependent and metabarcoding (ITS2 for fungi, V3-V4 region for bacteria) approaches. Olives and brines were also sampled for volatiles, organic acids and phenolic compounds. No major differences in microbiota composition were observed according to olive type or harvest period. Throughout the fermentation, yeasts were clearly the most dominant. ITS2 sequencing data revealed complex fungal diversity dominated by , , , and species. Bacterial communities were dominated by the genus, while lactic acid bacteria remained scarce. Clear shifts in microbial communities and biochemical profiles were observed during fermentation and, by correlating metabolites and microbiota changes, four different phases were distinguished. During the first 7 days, phase I, a fast decrease of filamentous fungal and bacterial populations was observed. Between days 21 and 120, phase II, and for fungi and for bacteria dominated the fermentation and were linked to the pH decrease and citric acid production. Phase III, between 120 and 183 days, was characterized by an increase in acids and esters and correlated to increased abundances of , and During the last months of fermentation, phase IV, microbial communities were dominated by and . Both species were strongly correlated to an increase in fruity esters and alcohol abundances. Overall, this study provides an in-depth understanding about microbial species succession and how the microbiota shapes the final distinct olive characteristics. It also constitutes a first step to identify key drivers of this fermentation.
PubMed: 33133054
DOI: 10.3389/fmicb.2020.586614 -
Frontiers in Microbiology 2022The aim of this study was to investigate the influence of , alone or in combination with a214 or citric acid, on forage oat silage quality, bacterial and fungal...
The aim of this study was to investigate the influence of , alone or in combination with a214 or citric acid, on forage oat silage quality, bacterial and fungal microbiological profile during ensiling and aerobic exposure. With the exception of , all additives could improve silage quality of forage oat based on lower ammonia-nitrogen content and higher residual of water soluble carbohydrates during anaerobic fermentation compared to control silage, especially in combined with citric acid (CAPF). was the dominant bacteria in all silages, while CAPF group increased the relative abundance of and compared to control silage. The application of suppressed the relative abundance of yeasts such as and in response to aerobic exposure, especially in CAPF treatment, leading to high acetic acids and lower dry matter loss, as well as good aerobic stability. Therefore, , alone or in combination with citric acid, has potential to improve aerobic stability of forage oat silage by shifting bacterial and fungal community composition, and can be used as new additive to prepare high-quality silage for animal production.
PubMed: 36605512
DOI: 10.3389/fmicb.2022.1053933 -
BMC Microbiology Oct 2020Pathogenic fungi often cause serious infections mainly in immunocompromised persons. The number of infections caused by the non-albicans Candida or other species has...
BACKGROUND
Pathogenic fungi often cause serious infections mainly in immunocompromised persons. The number of infections caused by the non-albicans Candida or other species has significantly increased over the last years. These infections present a major challenge in the health sector because these pathogenic fungi have strong virulence and often show resistance to the commonly used antifungal treatments. To solve the problems caused by the drug resistant pathogenic fungi, it is necessary to find new antifungal agents and their sources. The aim of this study was to give evidence that yeasts can effectively fight against strains which belong to pathogenic fungi and reveal those yeasts which are able to inhibit growth of Kodamaea ohmeri, Pichia kudriavzevii, Naganishia albida or Candida tropicalis. Furthermore, we wanted to determine the effects of certain culturing factors on the growth inhibition.
RESULTS
Our screening revealed that although the strains belonging to pathogenic species were much more tolerant to the yeast-produced bioactive agents than the non-disease-associated yeasts, growth of Kodamaea ohmeri and Candida tropicalis could be inhibited by Metschnikowia andauensis, while Naganishia albida could be controlled by Pichia anomala or Candida tropicalis. Our data proved that the experimental circumstances could have a serious impact on the inhibitory capacity of the yeasts. Appearance of inhibition strongly depended on media, pH and temperature. Our data also shed some light on the fact that Pichia kudriavzevii must have high natural resistance to the yeast-produced agents, while other species, such as Saccharomycopsis crataegensis belonged to the easily inhibitable species.
CONCLUSIONS
Our study suggests that yeast-produced bioactive agents could be potential growth inhibitory agents against the disease-associated fungi and yeasts can also contribute to alternative approaches to combat against pathogenic fungi. Our data revealed an important role of the culturing factors in inhibition and pointed to the complex nature of antagonism.
Topics: Antifungal Agents; Candidiasis; Drug Resistance, Fungal; Microbial Sensitivity Tests; Yeasts
PubMed: 33087058
DOI: 10.1186/s12866-020-01942-0 -
Environmental Microbiology Apr 2011While symbiosis between bacteria and insects has been thoroughly investigated in the last two decades, investments on the study of yeasts associated with insects have...
While symbiosis between bacteria and insects has been thoroughly investigated in the last two decades, investments on the study of yeasts associated with insects have been limited. Insect-associated yeasts are placed on different branches of the phylogenetic tree of fungi, indicating that these associations evolved independently on several occasions. Isolation of yeasts is frequently reported from insect habitats, and in some cases yeasts have been detected in the insect gut and in other organs/tissues. Here we show that the yeast Wickerhamomyces anomalus, previously known as Pichia anomala, is stably associated with the mosquito Anopheles stephensi, a main vector of malaria in Asia. Wickerhamomyces anomalus colonized pre-adult stages (larvae L(1)-L(4) and pupae) and adults of different sex and age and could be isolated in pure culture. By a combination of transmission electron microscopy and fluorescent in situ hybridization techniques, W. anomalus was shown to localize in the midgut and in both the male and female reproductive systems, suggesting multiple transmission patterns.
Topics: Animals; Anopheles; Asia; DNA, Fungal; Digestive System; Female; Genitalia, Female; Genitalia, Male; In Situ Hybridization, Fluorescence; Larva; Male; Microscopy, Electron, Transmission; Pichia; Polymerase Chain Reaction; Symbiosis
PubMed: 21208355
DOI: 10.1111/j.1462-2920.2010.02395.x -
Insects Apr 2022Here, we aimed to produce a natural food preservative using a crude extract from edible, immunized larvae (iTME), injected with edible bacteria using an edible solvent....
Here, we aimed to produce a natural food preservative using a crude extract from edible, immunized larvae (iTME), injected with edible bacteria using an edible solvent. Results showed that iTME had concentration-dependent inhibitory activity against food-poisoning bacteria , , and , as well as against harmful fungi , , and . Moreover, iTME showed antimicrobial activity against beneficial microorganisms and , but not . Furthermore, the minimum inhibitory concentration of iTME against , , and was 1 mg/mL, and iTME did not lose its inhibitory activity when treated at varying temperature, pH, and salinity. In addition, the antibacterial activity was lost after reacting the iTME with trypsin and chymotrypsin. The addition of iTME to Ganjang inoculated with harmful bacteria inhibited bacterial growth. Therefore, we propose that iTME can be used as a safe natural preservative to prolong food shelf life by inhibiting the growth of food-poisoning bacteria in a variety of foods, including traditional sauces.
PubMed: 35447823
DOI: 10.3390/insects13040381 -
Journal of Fungi (Basel, Switzerland) Sep 2020During the course of a screening for novel biologically active secondary metabolites produced by the Sordariomycetes (Ascomycota, Fungi), the ex-type strain of was...
During the course of a screening for novel biologically active secondary metabolites produced by the Sordariomycetes (Ascomycota, Fungi), the ex-type strain of was found to produce seven novel xanthone-anthraquinone heterodimers, xanthoquinodin A11 () and xanthoquinodins B10-15 (-), together with the already known compound xanthoquinodin B4 (). The structures of the xanthoquinodins were determined by analysis of the nuclear magnetic resonance (NMR) spectroscopic and mass spectrometric data. Moreover, the absolute configurations of these metabolites were established by analysis of the H-H coupling constants, nuclear Overhauser effect spectroscopy (NOESY) correlations, and Electronic Circular Dichroism (ECD) spectroscopic data. Antifungal and antibacterial activities as well as cytotoxicity of all compounds were tested. Xanthoquinodin B11 showed fungicidal activities against [minimum inhibitory concentration (MIC) 2.1 µg/mL], (MIC 2.1 µg/mL), and (MIC 8.3 µg/mL). All the compounds - displayed anti-Gram-positive bacteria activity (MIC 0.2-8.3 µg/mL). In addition, all these eight compounds showed cytotoxicity against KB 3.1, L929, A549, SK-OV-3, PC-3, A431, and MCF-7 mammalian cell lines. The six novel compounds (-, -), together with xanthoquinodin B4, were also found in the screening of other strains belonging to , revealing the potential chemotaxonomic significance of the compound class for the genus.
PubMed: 32992954
DOI: 10.3390/jof6040188