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1.
Food Res Int ; 162(Pt A): 111917, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36461184

RESUMO

The indigenous vineyard mycobiota contribute both to wine quality and vineyard sanitary status. Wines made from same grape variety but from different geographical locations are appreciated for their diversity. Because no information on indigenous mycobiota of Croatian grapevines is available, the aim of the present study was to start filling this knowledge gap by characterizing the indigenous mycobiota of Marastina variety. The use of metataxonomic approach has enabled the identification of 25 different fungal genera present on Marastina grape berries collected from 11 vineyards located within the Croatian coastal winegrowing region of Dalmatia (Northern Dalmatia, Dalmatian hinterland, Central and Southern Dalmatia). The substantial regional and local scale differences in their distribution were observed. Overall, Aureobasidium was the dominant genus followed by Cladosporium and Metschnikowia. Botrytis and Plenodomus were associated with the vineyards located in Central and Southern Dalmatia, whereas Pichia was associated with Northern Dalmatia vineyards. The largest abundance of Buckleyzyma, Cladosporium, Eremothecium, Fusarium, Papiliotrema, and Rhodotorula was observed in Dalmatian hinterland. Moreover, data suggested that climate conditions and soil type partially influenced the distribution of fungal communities. The local-scale differences emerged also for the physicochemical characteristics of fresh musts. The high malic acid content supported the development of Metschnikowia, and inhibited Fusarium growth, whereas a positive correlation between Erysiphe and pH values was observed. Sporobolomyces and Cystobasidium were negatively associated with high glucose concentration. The revealing of Marastina indigenous mycobiota provided information on the members of fungal community negatively influencing the grapevine sanitary status as well as those which could be employed in disease biocontrol.


Assuntos
Fusarium , Metschnikowia , Vitis , Vinho , Paladar , Croácia
2.
Dis Aquat Organ ; 152: 17-25, 2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36394137

RESUMO

Milky disease of Chinese mitten crab Eriocheir sinensis caused by Metschnikowia bicuspidata is a novel disease with high mortality. No effective treatment is currently available, but a rapid, accurate detection method is required for the prevention and control of the disease. In this study, the genome-sequencing results of M. bicuspidata and similar species were used for comparative genomic analysis for genes specific to M. bicuspidata. A quantitative PCR (qPCR) detection method for M. bicuspidata was then established using the specific primers and probes designed according to the sequence of a hypothetical protein gene specific to M. bicuspidata. The assay was found to have a high degree of repeatability and reproducibility, with a linear dynamic range (R2 = 0.998) extending over 9 log10 dilutions and a high efficiency (100.7%). Furthermore, the method showed high sensitivity, being able to detect at least 11.3 copies µl-1 of recombinant plasmid, and strong specificity, without any cross-reaction with any of the 9 species of yeast that are closely related to M. bicuspidata or any of 16 species of pathogenic bacteria commonly observed in aquatic animals. The established method was used to examine 138 apparently healthy crabs collected from 22 farms, with 21 samples (15.2%) found to be M. bicuspidata-positive. Thus, the developed qPCR assay is a specific, sensitive, stable, and rapid diagnostic method for the detection and quantification of M. bicuspidata DNA from E. sinensis tissues.


Assuntos
Metschnikowia , Animais , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase em Tempo Real/veterinária , China
3.
Front Cell Infect Microbiol ; 12: 930585, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35937694

RESUMO

In recent years, the "milky disease" caused by Metschnikowia bicuspidata has seriously affected the Eriocheir sinensis culture industry. Discovering and blocking the transmission route has become the key to controlling this disease. The existing polymerase chain reaction (PCR) detection technology for M. bicuspidata uses the ribosomal DNA (rDNA) sequence, but low sensitivity and specificity lead to frequent false detections. We developed a highly specific and sensitive nested PCR method to detect M. bicuspidata, by targeting the hyphally regulated cell wall protein (HYR) gene. This nested HYR-PCR produced a single clear band, showed no cross-reaction with other pathogens, and was superior to rDNA-PCR in specificity and sensitivity. The sensitivity of nested HYR-PCR (6.10 × 101 copies/µL) was greater than those of the large subunit ribosomal RNA gene (LSU rRNA; 6.03 × 104 copies/µL) and internal transcribed spacer (ITS; 6.74 × 105 copies/µL) PCRs. The nested HYR-PCR also showed a higher positivity rate (71.1%) than those obtained with LSU rRNA (16.7%) and ITS rDNA (24.4%). In conclusion, we developed a new nested HYR-PCR method for the specific and sensitive detection of M. bicuspidata infection. This will help to elucidate the transmission route of M. bicuspidata and to design effective management and control measures for M. bicuspidata disease.


Assuntos
Metschnikowia , DNA Ribossômico/genética , Metschnikowia/genética , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico/genética , Sensibilidade e Especificidade
4.
Arch Microbiol ; 204(6): 337, 2022 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-35587835

RESUMO

Yeasts can produce toxins in protein or glycoprotein structures that can act as an inhibitor on some bacteria and yeast species. The effects of those toxins on the growth of pathogenic and food spoilage microorganisms are subject to various studies. Metschnikowia pulcherrima was determined to be a killer toxin-producing yeast that was tested against three selected microorganisms, namely Escherichia coli Type-I, Micrococcus luteus and Candida albicans. The killer toxin only showed inhibitory activity against M. luteus. Different pH (5-6-7-8), temperature (20-25-30-35 °C) and carbon source (glucose-glycerol-ethanol-acetate) combinations were applied to stimulate the growth and toxin production of the killer yeast. The greatest increase among the different combinations was obtained at 20 °C and pH 7 when glycerol was used as the main carbon source. It was then also tested against other pathogen indicators or pathogens under these conditions. The killer toxin was partially purified by ethanol precipitation and showed inhibitory activity against M. luteus (36 mm). According to the protein profile obtained by SDS-PAGE, the molecular weight of the inhibitor toxin was measured about 7.4 kDa. The molecular weight with amino acid sequence of the killer toxin was 10.3 kDa and determined by MALDI-TOF mass spectrometry.


Assuntos
Glicerol , Metschnikowia , Carbono/metabolismo , Escherichia coli , Etanol/metabolismo , Glicerol/metabolismo , Leveduras
5.
Sci Total Environ ; 833: 155296, 2022 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-35429554

RESUMO

Pesticides are a major anthropogenic threat to the biodiversity of freshwater ecosystems, having the potential to affect non-target aquatic organisms and disrupt the processes in which they intervene. Important knowledge gaps have been recognised concerning the ecological effects of synthetic fungicides on non-target symbiotic aquatic fungi and the ecological processes where they intervene. The goal of this work was to assess the influence of three commonly used fungicides (myclobutanil, metalaxyl and cymoxanil), which differ in their mode of action, on a host (the crustacean Daphnia magna) × parasite (the yeast Metschnikowia bicuspidata) experimental model. Using a set of life history experiments, we evaluated the effect of each fungicide on the outcome of this relationship (disease) and on the fitness of both host and parasite. Contrasting results were observed: (i) cymoxanil and metalaxyl were overall innocuous to host and parasite at the tested concentrations, although host reproduction was occasionally reduced in the simultaneous presence of parasite and fungicide; (ii) on the contrary, myclobutanil displayed a clear antifungal effect, decreasing parasite prevalence and alleviating infection signs in the hosts. This antiparasitic effect of myclobutanil was further investigated with a follow-up experiment that manipulated the timing of application of the fungicide, to understand which stage of parasite development was most susceptible: while myclobutanil did not interfere in the early stages of infection, its antifungal activity was clearly observable at a later stage of the disease (by impairing the production of transmission stages of the parasite). More research is needed to understand the broader consequences of this parasite-clearance effect, especially in face of increasing evidence that parasites are ecologically more important than their cryptic nature might suggest.


Assuntos
Fungicidas Industriais , Metschnikowia , Parasitos , Poríferos , Agroquímicos , Animais , Antifúngicos , Antiparasitários , Daphnia , Ecossistema , Fungicidas Industriais/toxicidade
6.
Appl Biochem Biotechnol ; 194(7): 3119-3135, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35347674

RESUMO

D-Arabitol is an important functional sugar alcohol, which can be used in the preparation of foods, chemicals, and medicines. Despite biological production of D-arabitol from low-cost substrates has recently been the focus of research, low yield of this technology has limited its large-scale exploitation. Optimization of this bioprocess could be a promising option to improve the yield of D-arabitol. In this study, one-factor-at-a-time (OFAT) strategy and Box-Behnken design (BBD) were used to increase D-arabitol production by Metschnikowia reukaufii CICC 31,858 through optimizing the fermentation conditions and medium composition. The OFAT optimization provided the optimal conditions for temperature, agitation speed, and fermentation time of 30℃, 220 rpm, and 6 days, respectively. Likewise, the optimum concentrations of peptone, ammonium sulfate, KH2PO4, MgSO4·7H2O, and fumaric acid in the fermentation medium were (g/L) 7.5, 1, 2, 0.5, and 7.5, respectively. Under these optimum conditions, 80.43 g/L of D-arabitol was produced from 200 g/L of glucose, with a productivity of 0.56 g/L/h. The BBD optimization with three important components of fermentation medium (KH2PO4, MgSO4·7H2O, and fumaric acid) showed that the predicted titer of D-arabitol varied from 47.21 to 89.27 g/L, and the actual titer of D-arabitol ranged from 47.36 to 89.83 g/L. The optimum concentrations (g/L) of KH2PO4, MgSO4·7H2O, and fumaric acid in the fermentation medium were found to be 1.0, 0.5, and 4.7 g/L, respectively. Under the optimum conditions, 92.45 g/L of D-arabitol was finally produced with the yield and productivity of 0.46 g/g and 0.64 g/L/h, respectively.


Assuntos
Glucose , Álcoois Açúcares , Meios de Cultura/química , Fermentação , Metschnikowia
7.
Transbound Emerg Dis ; 69(5): 3133-3141, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35076183

RESUMO

The Chinese grass shrimp (Palaemonetes sinensis) was found with a white turbidity appearance in the Panjin area. After dissection, typical symptoms of milky disease with hemolymph emulsification and noncoagulation were observed; however, the pathogen was unknown. In this study, we aimed to isolate the pathogen of the diseased P. sinensis. We found that the pathogen could grow on the fungal medium Bengal red, and microscopic examination showed that it reproduced by budding. Molecular identification of the isolated and purified yeast strain LNMB2021 based on 26S rDNA sequence showed that the pathogenic pathogen was Metschnikowia bicuspidata (GenBank OK094821), with 98.74% homology with M. bicuspidata strain LNES0119 (GenBank OK073903) and 98.56% with M. bicuspidata strain Liao (GenBank MT856369). The results of an artificial infection test showed that M. bicuspidata caused the same clinical symptoms in P. sinensis, and the isolated pathogen was still the same, which proved that P. sinensis was a new host of M. bicuspidata. Histopathological analysis showed that there were obvious pathological changes in the hepatopancreas and muscle tissue of the diseased P. sinensis. Identification of the pathogen is essential for the prevention and control of the disease and the healthy culture of P. sinensis. Furthermore, considering the transmissibility and cross-host transmission of M. bicuspidata, its risk of infecting other aquatic animals deserves high attention.


Assuntos
Metschnikowia , Palaemonidae , Animais , China/epidemiologia , DNA Ribossômico , Metschnikowia/genética , Palaemonidae/genética , Palaemonidae/microbiologia
8.
J Fish Dis ; 45(1): 41-49, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34525224

RESUMO

A severe disease occurred in farmed Eriocheir sinensis characterized by milky liquid accumulation in the pectoral cavity, in the province of Liaoning, China, during October 2018-April 2019. Diseased crabs moved sluggishly, exhibited appetite loss and readily lost legs. Under the microscopic analysis, it was observed that the milky liquid contained a large number of yeastlike microorganisms (0.8-1.2 µm × 1.5-1.9 µm), which were also present in the muscle, hepatopancreas and gills. A dominant strain was isolated from the milky liquid and other tissues of diseased crabs. It grew on nutrient agar and formed 1- to 3-mm white opaque colonies, each with a protuberance in the centre. Besides, the results of TEM and SEM also demonstrate a typical multilateral budding model of the yeast clearly. We identified the strain, which we named 2EJM001, as Metschnikowia bicuspidata based on 18S rDNA, ITS and 26S rDNA sequence analyses and on its morphological, physiological and biochemical characteristics. Phylogenetic analysis revealed that 26S rDNA of 2EJM001 was clustered with M. bicuspidata (LNES0119) as reported by Bao et al. In addition, unlike Bao et al., two challenge experiments (injection and immersion) were used in this study. The results of challenge experiments show that 2EJM001 was pathogenic to E. sinensis and caused signs similar to those found in the naturally infected crabs. At the same time, the minimum inhibitory concentrations (MIC80 and MIC90 ) were determined. This study further confirms that M. bicuspidata 2EJM001 was the pathogen responsible for 'milky disease' in E. sinensis from Liaoning Province.


Assuntos
Braquiúros , Doenças dos Peixes , Animais , Antifúngicos , Metschnikowia , Filogenia
9.
Food Chem ; 370: 131049, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34520974

RESUMO

Black currants (Ribes nigrum) were fermented with Saccharomyces and non-Saccharomyces yeasts without added sugar to yield low-ethanol-content beverages. The effects of yeasts on the volatile compounds and sensory characteristics were analysed by HS-SPME-GC-MS, GC-O, and generic descriptive analysis. Ninety-eight volatile compounds were identified from the black currant juice and fermented beverages. Significant increases in the contents of esters (131 %), higher alcohols (391 %), and fatty acids (not present in juice sample) compared to initial juice were observed depending on the yeasts used. GC-O analysis revealed the higher impact of esters on the sensory properties of Saccharomyces bayanus-fermented beverage compared to the Torulaspora delbrueckii-fermented beverage. In the sensory evaluation, non-Saccharomyces yeasts resulted in a higher 'black currant odour'. However, all beverages were intensely sour, which can be a significant challenge in the development of alcoholic berry beverages.


Assuntos
Metschnikowia , Ribes , Saccharomyces , Torulaspora , Vinho , Bebidas Alcoólicas/análise , Fermentação , Vinho/análise , Leveduras
10.
Food Microbiol ; 101: 103888, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34579848

RESUMO

This study investigated the effect of arginine (Arg) on the antagonistic activity of Metschnikowia citriensis against sour rot caused by Geotrichum citri-aurantii in postharvest citrus, and evaluated the possible mechanism therein. Arg treatment up-regulated the PUL genes expression, and significantly induced the pulcherriminic acid (PA) production of M. citriensis, which related to the capability of iron depletion of M. citriensis. By comparing the biocontrol effects of Arg-treated and untreated yeast cells, it was found that Arg treatment significantly enhanced the biocontrol efficacy of M. citriensis, and 5 mmol L-1 Arg exerted the best effect. Additionally, the biofilm formation ability of M. citriensis was greatly enhanced by Arg, and the higher population density of yeast cells in citrus wounds was also observed in Arg treatment groups stored both at 25 °C and 4 °C. Moreover, Arg was shown to function as a cell protectant to elevate antioxidant enzyme activity [including catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPX)] and intracellular trehalose content to resist oxidative stress damage, that directly helped to enhance colonization ability of yeasts in fruit wounds. These results suggest the application of Arg is a useful approach to improve the biocontrol performance of M. citriensis.


Assuntos
Agentes de Controle Biológico , Citrus , Geotrichum/patogenicidade , Metschnikowia/fisiologia , Doenças das Plantas/prevenção & controle , Arginina , Frutas/microbiologia , Doenças das Plantas/microbiologia
11.
G3 (Bethesda) ; 11(11)2021 10 19.
Artigo em Inglês | MEDLINE | ID: mdl-34849782

RESUMO

The new yeast Metschnikowia persimmonesis KCTC 12991BP (KIOM G15050 strain) exhibits strong antimicrobial activity against some pathogens. This activity may be related to the medicinal profile of secondary metabolites that could be found in the genome of this species. Therefore, to explore its future possibility of producing some beneficial activities, including medicinal ability, we report high-quality whole-genome assembly of M. persimmonesis produced by PacBio RS II sequencer. The final draft assembly consisted of 16 scaffolds with GC content of 45.90% and comprised a fairly complete set (82.8%) of BUSCO result using Saccharomycetales lineage data set. The total length of the genome was 16.473 Mb, with a scaffold N50 of 1.982 Mb. Annotation of the M. persimmonesis genome revealed presence of 7029 genes and 6939 functionally annotated proteins. Based on the analysis of phylogenetic relationship and the average nucleotide identities, M. persimmonesis was proved to a novel species within the Metschnikowia genus. This finding is expected to significantly contribute to the discovery of high-value natural products from M. persimmonesis as well as for genome biology and evolution comparative analysis within Metschnikowia species.


Assuntos
Diospyros , Metschnikowia , Plantas Medicinais , Diospyros/genética , Anotação de Sequência Molecular , Filogenia
12.
Sci Rep ; 11(1): 15795, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34349183

RESUMO

AgNPs are nanomaterials with many potential biomedical applications. In this study, the two novel yeast strains HX-YS and LPP-12Y capable of producing biological silver nanoparticles were isolated. Sequencing of ribosomal DNA-ITS fragments, as well as partial D1/D2 regions of 26S rDNA indicated that the strains are related to species from the genus Metschnikowia. The BioAgNPs produced by HX-YS and LPP-12Y at pH 5.0-6.0 and 26 °C ranged in size from 50 to 500 nm. The antibacterial activities of yeast BioAgNPs against five pathogenic bacteria were determined. The highest antibacterial effect was observed on P. aeruginosa, with additional obvious effects on E. coli ATCC8099 and S. aureus ATCC10231. Additionally, the BioAgNPs showed antiproliferative effects on lung cancer cell lines H1975 and A579, with low toxicity in Beas 2B normal lung cells. Therefore, the AgNPs biosynthesized by HX-YS and LPP-12Y may have potential applications in the treatment of bacterial infections and cancer.


Assuntos
Proliferação de Células/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Neoplasias Pulmonares/patologia , Nanopartículas Metálicas , Metschnikowia/metabolismo , Nanoestruturas , Pseudomonas aeruginosa/efeitos dos fármacos , Compostos de Prata/metabolismo , Compostos de Prata/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Linhagem Celular Tumoral , DNA Ribossômico , Humanos , Metschnikowia/genética , Metschnikowia/isolamento & purificação
13.
Am Nat ; 198(3): 317-332, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34403315

RESUMO

AbstractWithin-host processes (representing the entry, establishment, growth, and development of a parasite inside its host) may play a key role in parasite transmission but remain challenging to observe and quantify. We develop a general model for measuring host defenses and within-host disease dynamics. Our stochastic model breaks the infection process down into the stages of parasite exposure, entry, and establishment and provides associated probabilities for a host's ability to resist infections with barriers and clear internal infections. We tested our model on Daphnia dentifera and the parasitic fungus Metschnikowia bicuspidata and found that when faced with identical levels of parasite exposure, Daphnia patent (transmitting) infections depended on the strength of internal clearance. Applying a Gillespie algorithm to the model-estimated probabilities allowed us to visualize within-host dynamics, within which signatures of host defense could be clearly observed. We also found that early within-host stages were the most vulnerable to internal clearance, suggesting that hosts have a limited window during which recovery can occur. Our study demonstrates how pairing longitudinal infection data with a simple model can reveal new insight into within-host dynamics and mechanisms of host defense. Our model and methodological approach may be a powerful tool for exploring these properties in understudied host-parasite interactions.


Assuntos
Interações Hospedeiro-Patógeno , Metschnikowia , Animais , Daphnia , Interações Hospedeiro-Parasita
14.
Toxins (Basel) ; 13(6)2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34199507

RESUMO

Wild yeasts isolated from the surface of apples were screened for antagonistic activity against Penicillium expansum, the main producer of the mycotoxin patulin. Three antagonistic yeasts (Y33, Y29 and Y24) from a total of 90 were found to inhibit P. expansum growth. Identification by ITS region sequence and characterization showed that three selected isolates of yeast should be different strains of Metschnikowia pulcherrima. Several concentrations of the selected yeasts were used to study their in vitro antifungal effectivity against P. expansum on Petri dishes (plates with 63.6 cm2 surface) whereas their potential activity on patulin reduction was studied in liquid medium. Finally, the BCA that had the best in vitro antifungal capacity against P. and the best patulin degradation capacity was selected to be assessed directly on apples. All the selected strains demonstrated antifungal activity in vitro but the most efficient was the strain Y29. Isolated strains were able to reduce patulin content in liquid medium, Y29 being the only strain that completely reduced patulin levels within 120 h. The application of Y29 as biocontrol agent on the surface of apples inoculated with P. expansum, inhibited fungal growth and patulin production during storage. Therefore, the results shown that this yeast strain could be used for the reduction of P. expansum and its mycotoxin in apples or apple-based products by adapting the procedure application.


Assuntos
Agentes de Controle Biológico , Frutas/microbiologia , Malus/microbiologia , Metschnikowia/isolamento & purificação , Patulina/metabolismo , Penicillium/crescimento & desenvolvimento , Frutas/química , Malus/química , Metschnikowia/metabolismo , Patulina/análise , Doenças das Plantas/prevenção & controle
15.
Parasitology ; 148(11): 1303-1312, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34103104

RESUMO

Genetic variation in parasites has important consequences for host­parasite interactions. Prior studies of the ecologically important parasite Metschnikowia bicuspidata have suggested low genetic variation in the species. Here, we collected M. bicuspidata from two host species (Daphnia dentifera and Ceriodaphnia dubia) and two regions (Michigan and Indiana, USA). Within a lake, outbreaks tended to occur in one host species but not the other. Using microsatellite markers, we identified six parasite genotypes grouped within three distinct clades, one of which was rare. Of the two main clades, one was generally associated with D. dentifera, with lakes in both regions containing a single genotype. The other M. bicuspidata clade was mainly associated with C. dubia, with a different genotype dominating in each region. Despite these associations, both D. dentifera- and C. dubia-associated genotypes were found infecting both hosts in lakes. However, in lab experiments, the D. dentifera-associated genotype infected both D. dentifera and C. dubia, but the C. dubia-associated genotype, which had spores that were approximately 30% smaller, did not infect D. dentifera. We hypothesize that variation in spore size might help explain patterns of cross-species transmission. Future studies exploring the causes and consequences of variation in spore size may help explain patterns of infection and the maintenance of genotypic diversity in this ecologically important system.


Assuntos
Variação Genética , Metschnikowia/genética , Análise de Variância , Animais , Daphnia/microbiologia , Genótipo , Interações Hospedeiro-Parasita , Lagos , Metschnikowia/classificação , Michigan , Esporos Fúngicos/ultraestrutura , Zooplâncton/microbiologia
16.
Food Res Int ; 143: 110311, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33992330

RESUMO

The aim of the present study was to assess the cultivable microbiota of "mothers" of Vino cotto collected from production of different years 1890, 1895, 1920, 1975, 2008. A total of 73 yeasts and 81 bacteria were isolated. Starmerella lactis-condensi, Starmerella bacillaris, Hanseniaspora uvarum, Saccharomyces cerevisiae, Hanseniaspora guillermondi and Metschnikowia pulcherrima were identified. Bacteria isolates belonged to lactic acid bacteria (Lactiplantibacillus plantarum and Pediococcus pentosaceus) and acetic acid bacteria (Gluconobacter oxydans). Remarkable biodiversity was observed for Starm. bacillaris, as well as L. plantarum and G. oxydans. Organic acids and volatile compounds were also determined. Malic and succinic acids were the main ones with values ranging from 8.49 g/L to 11.76 g/L and from 4.15 g/L to 7.73 g/L respectively, while citric acid was present at low concentrations (<0.2 g/L) in all samples. Esters and higher alcohols were the main volatile compounds detected followed by alkanes. This study permits to better understand the microbial communities associated to this product and could be considered a starting point for the definition of tailored starter cultures to improve the quality of Vino cotto preserving its typical traits.


Assuntos
Vinho , Fermentação , Hanseniaspora , Metschnikowia , Saccharomycetales , Vinho/análise
17.
Sci Rep ; 11(1): 10593, 2021 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-34011985

RESUMO

Biological control against microbial infections has a great potential as an alternative approach instead of fungicidal chemicals, which can cause environmental pollution. The pigment producer Metschnikowia andauensis belongs to the antagonistic yeasts, but details of the mechanism by which it inhibits growth of other microbes are less known. Our results confirmed its antagonistic capacity on other yeast species isolated from fruits or flowers and demonstrated that the antagonistic capacity was well correlated with the size of the red pigmented zone. We have isolated and characterized its red pigment, which proved to be the iron chelating pulcherrimin. Its production was possible even in the presence of 0.05 mg/ml copper sulphate, which is widely used in organic vineyards because of its antimicrobial properties. Production and localisation of the pulcherrimin strongly depended on composition of the media and other culture factors. Glucose, galactose, disaccharides and the presence of pectin or certain amino acids clearly promoted pigment production. Higher temperatures and iron concentration decreased the diameter of red pigmented zones. The effect of pH on pigment production varied depending of whether it was tested in liquid or solid media. In addition, our results suggest that other mechanisms besides the iron depletion of the culture media may contribute to the antagonistic capacity of M. andauensis.


Assuntos
Aminoácidos Sulfúricos/biossíntese , Espaço Extracelular/enzimologia , Metschnikowia/metabolismo , Carbono/farmacologia , Contagem de Células , Cobre/metabolismo , Concentração de Íons de Hidrogênio , Íons , Ferro/metabolismo , Metschnikowia/efeitos dos fármacos , Metschnikowia/crescimento & desenvolvimento , Piperidinas , Polissacarídeos/farmacologia , Temperatura , Leveduras/efeitos dos fármacos , Leveduras/crescimento & desenvolvimento
18.
Front Immunol ; 12: 659723, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33868309

RESUMO

The "milky disease" of the Chinese mitten crab, Eriocheir sinensis, is a highly lethal fungal disease caused by Metschnikowia bicuspidata infection. To elucidate the immune responses of the hemolymph of E. sinensis to M. bicuspidata infection, a comparative analysis of the hemolymph of E. sinensis infected with M. bicuspidata and that treated with phosphate buffered saline was performed using label-free quantitative proteomics. A total of 429 proteins were identified. Using a 1.5-fold change in expression as a physiologically significant benchmark, 62 differentially expressed proteins were identified, of which 38 were significantly upregulated and 24 were significantly downregulated. The upregulated proteins mainly included cytoskeleton-related proteins (myosin regulatory light chain 2, myosin light chain alkali, tubulin α-2 chain, and tubulin ß-1 chain), serine protease and serine protease inhibitor (clip domain-containing serine protease, leukocyte elastase inhibitor, serine protein inhibitor 42Dd), catalase, transferrin, and heat shock protein 70. Upregulation of these proteins indicated that phenoloxidase system, phagocytosis and the ROS systems were induced by M. bicuspidata. The downregulated proteins were mainly organ and tissue regeneration proteins (PDGF/VEGF-related factor protein, integrin-linked protein kinase homing pat-4 gene) and hemagglutination-associated proteins (hemolymph clottable protein, hemocyte protein-glutamine gamma-glutamyltransferase). Downregulation of these proteins indicated that M. bicuspidata inhibited hemocyte regeneration and hemolymph agglutination. Fifteen differentially expressed proteins related to immunity were verified using a parallel reaction monitoring method. The expression trend of these proteins was similar to that of the proteome. To the best of our knowledge, this is the first report on the proteome of E. sinensis in response to M. bicuspidata infection. These results not only provide new and important information on the immune response of crustaceans to yeast infection but also provide a basis for further understanding the molecular mechanism of complex host pathogen interactions between crustaceans and fungi.


Assuntos
Proteínas de Artrópodes/metabolismo , Braquiúros/metabolismo , Hemolinfa/metabolismo , Proteoma/metabolismo , Proteômica/métodos , Animais , Proteínas de Artrópodes/genética , Proteínas de Artrópodes/isolamento & purificação , Braquiúros/genética , Braquiúros/microbiologia , China , Cromatografia Líquida/métodos , Feminino , Regulação da Expressão Gênica , Ontologia Genética , Hemolinfa/microbiologia , Interações Hospedeiro-Patógeno , Masculino , Metschnikowia/fisiologia , Proteoma/genética , Espectrometria de Massas em Tandem/métodos
19.
J Food Sci ; 86(6): 2327-2345, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33929752

RESUMO

ß-glucosidase is a pivotal enzyme that hydrolyzes bound volatile aromatic compounds. However, the activity of ß-glucosidase in winemaking and the mechanism by which it affects the flavor and taste of wines have not been fully investigated. In this study, we profiled the characteristics of ß-glucosidase derived from wine-related yeasts isolated from different wine-making regions in China, and analyzed the enzyme activity from different parts of the cells under aerobic and anaerobic conditions. A total of 56 strains of wine-related yeasts producing ß-glucosidases were screened using the YNB-C medium (YNB 6.7 g L-1 , cellobiose 5 g L-1 , pH 5.0). We found that strain Clavispora lusitaniae C117 produced the highest enzyme activity (152.39 µmol pNP ml-1 h-1 ). In most strains, ß-glucosidase were located in whole cells (periplasmic space) and permeabilized cells (intracellular). The non-Saccharomyces species had the highest enzymatic activity in a strain-dependent manner. Under aerobic conditions, C. lusitaniae C117, Hanseniaspora guilliermondii A27-3-4, Metschnikowia pulcherrima F-1-6, and Pichia anomala C84 had the highest ß-glucosidase activity. We further investigated the ß-glucosidase activity during the wine fermentation and the effects of sugar, pH, temperature, and ethanol on the enzyme activities of P. anomala C84 and commercial Saccharomyces yeast strains RC212 and VL1. The presence of fructose, glucose, and sucrose strongly inhibited enzyme activity. Similarly, low pH and low temperature inhibited the activity of ß-glucosidase, whereas ethanol promoted enzyme activity. Our findings provide a theoretical basis on understanding the different yeast characteristics of ß-glucosidase and their potential application for further improving wine aroma complexity.


Assuntos
Hanseniaspora/enzimologia , Metschnikowia/enzimologia , Odorantes/análise , Saccharomycetales/enzimologia , Vinho/análise , beta-Glucosidase/metabolismo
20.
Int J Food Microbiol ; 345: 109154, 2021 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-33735783

RESUMO

A novel killer toxin produced by yeast Metschnikowia pulcherrima was purified and added into ready to cook meatballs to enhance their microbial safety and extension of their shelf life. The agent was added into ready to cook meatballs at two different concentrations (1%-K1 and 2%-K2). The results of those two groups were compared to the control group (K0) lacking the killer toxin. Physical, chemical and microbiological analyses were carried out in meat dough and all analyses were repeated at two day intervals during 10 day-storage at +4 °C. Addition of inhibitor compound in meat dough decreased the numbers of total aerobic mesophillic bacteria, yeast and molds and lactic acid bacteria. Staphylococci/Micrococci, coliform bacteria and total psychrotrophic bacterial counts of the samples were determined as well. Results showed that all indicators of microbial deterioration were found to be higher in K1 group than K2 group, revealing that there was an inverse correlation between the concentration of killer toxin and the number of microorganisms causing spoilage. In addition to 1 log decrease in the number of microorganisms in toxin added groups, the high TBARS values of the control group also showed the effectiveness of the toxin. Toxic effect analysis results showed that the killer toxin had no toxic effect on L929 mouse fibroblast cells after 24h exposure.


Assuntos
Antibacterianos/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Metschnikowia/metabolismo , Micotoxinas/farmacologia , Staphylococcus/efeitos dos fármacos , Animais , Bovinos , Linhagem Celular , Contagem de Colônia Microbiana , Armazenamento de Alimentos , Carne/microbiologia , Camundongos
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