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1.
FEMS Yeast Res ; 22(1)2022 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-35932192

RESUMO

Zygosaccharomyces rouxii is an osmotolerant and halotolerant yeast that can participate in fermentation. To understand the mechanisms of salt and sugar tolerance, the transcription levels of Z. rouxii M 2013310 under 180 g/L NaCl stress and 600 g/L glucose stress were measured. The transcriptome analysis showed that 2227 differentially expressed genes (DEGs) were identified under 180 g/L NaCl stress, 1530 DEGs were identified under 600 g/L glucose stress, and 1278 DEGs were identified under both stress conditions. Then, KEGG enrichment analyses of these genes indicated that 53.3% of the upregulated genes were involved in the ergosterol synthesis pathway. Subsequently, quantitative PCR was used to verify the results, which showed that the genes of the ergosterol synthesis pathway were significantly upregulated under 180 g/L NaCl stress. Finally, further quantitative testing of ergosterol and spotting assays revealed that Z. rouxii M 2013310 increased the amount of ergosterol in response to high salt stress. These results highlighted the functional differences in ergosterol under sugar stress and salt stress, which contributes to our understanding of the tolerance mechanisms of salt and sugar in Z. rouxii.


Assuntos
Zygosaccharomyces , Ergosterol/metabolismo , Glucose/metabolismo , Saccharomyces cerevisiae/genética , Saccharomycetales , Cloreto de Sódio/metabolismo , Açúcares/metabolismo , Zygosaccharomyces/fisiologia
2.
J Food Sci ; 87(9): 4119-4136, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35986680

RESUMO

This work aimed for the first time to provide detailed insights into thymol and trans-cinnamaldehyde's mechanisms of action on the food-spoilage yeast Zygosaccharomyces rouxii and offers evidence in favor of the activation of an apoptosis-like phenotype. The action mechanisms of thymol and trans-cinnamaldehyde were investigated by the measurement of a series of typical apoptotic features using flow cytometer or microplate reader. Moreover, quantitative reverse transcription PCR (QRT-PCR) was performed to investigate the effects of thymol and trans-cinnamaldehyde on the transcription of key regulators of apoptosis in Z. rouxii. The results indicated that the treatment of Z. rouxii with thymol or trans-cinnamaldehyde (minimum inhibitory and subinhibitory concentrations) triggered reactive oxygen species (ROS) accumulation, elevated intracellular Ca2+ level, and depolarized mitochondrial membrane potential (MMP) coupled with hallmarks of apoptosis including mitochondrial cytochrome c (cyt c) release, metacaspase activation, phosphatidylserine (PS) exposure, and DNA fragmentation. Moreover, thymol or trans-cinnamaldehyde treatment upregulated the transcription of proapoptotic regulators including Yca1, Dnm1, Nuc1, Ndi1, and Mmi1 and downregulated the transcription of antiapoptotic regulators of Fis1 and Cdc48, further confirming the apoptosis induced by thymol and trans-cinnamaldehyde in Z. rouxii. In summary, thymol and trans-cinnamaldehyde probably induced apoptosis through a metacaspase-dependent mitochondrial pathway in Z. roxuii. These findings provide theoretical support for the development of safe and efficient agents used in food preservation. PRACTICAL APPLICATION: The results will provide a new idea for the systematic analysis of the antifungal mechanisms of thymol and trans-cinnamaldehyde and also provide a theoretical support for the development and application of natural food preservatives, which is of positive significance for the effective control of the spoilage caused by Z. rouxii in food processing and storage and the protection of consumers' health.


Assuntos
Proteínas de Saccharomyces cerevisiae , Zygosaccharomyces , Acroleína/análogos & derivados , Antifúngicos/farmacologia , Apoptose , Citocromos c/farmacologia , Complexo I de Transporte de Elétrons , Endonucleases , Exonucleases , Conservantes de Alimentos/farmacologia , Proteínas Mitocondriais/farmacologia , Fosfatidilserinas/farmacologia , Espécies Reativas de Oxigênio , Saccharomyces cerevisiae/genética , Saccharomycetales , Timol/farmacologia , Zygosaccharomyces/genética
3.
Methods Mol Biol ; 2513: 179-204, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35781206

RESUMO

Microorganisms offer a tremendous potential as cell factories, and they are indeed been used by humans since the previous centuries for biotransformations. Among them, yeasts combine the advantage of a unicellular state with a eukaryotic organization. Moreover, in the era of biorefineries, their biodiversity can offer solutions to specific process constraints. Zygosaccharomyces bailii, an ascomycete budding yeast, is widely known for its peculiar tolerance to different stresses, among which are organic acids. Moreover, the recent reclassification of the species, including diverse hybrids, is further expanding both fundamental and applied interests. It is therefore reasonable that despite the possibility to apply with this yeast some of the molecular tools and protocols routinely used to manipulate Saccharomyces cerevisiae, adjustments and optimizations are necessary. Here we describe in detail the methods for determining chromosome number, size, and aneuploidy, transformation, classical target gene disruption or gene integration, and designing of episomal expression plasmids helpful for engineering the yeast Z. bailii .


Assuntos
Saccharomycetales , Zygosaccharomyces , Ácidos , Humanos , Saccharomyces cerevisiae , Saccharomycetales/genética , Zygosaccharomyces/genética , Zygosaccharomyces/metabolismo
4.
Food Res Int ; 156: 111347, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35650976

RESUMO

The soy sauce produced by Cantonese fermentation has a unique flavor, among which brine fermentation plays an important role. In this fermentation process, 61 volatile compounds, including 19 esters, 10 aldehydes, 9 alcohols, 5 phenols, and 18 others, were identified by headspace solid-phase microextraction-gas chromatography-mass spectrometry. Seventeen kinds of free amino acids were detected by high-performance liquid chromatography. Results showed that Touyou, which comprised 1.5 g/100 g total nitrogen, 1.0 g/100 mL amino acid nitrogen, 3.66 g/100 g reducing sugar, 1.44 g/100 mL total acid, 17.04 g/100 mL salt content, and 27.3% umami free amino acids, had excellent quality. High-throughput sequencing was used to identify microorganisms. The top 3 of bacteria were Weissella, Staphylococcus, and Lactobacillus, and the top 3 fungi were Aspergillus, Zygosaccharomyces, and Candida. The co-occurrence network analysis of microorganisms showed that the top-ranked microorganisms were Plectosphaerella, Aureobasidium, unidentified_Mortierellales_sp, Glutinomyces, Faecalibacterium, and Cladophialophora. Then, eight microorganisms (VIP[pred] > 1) were obtained by two-way orthogonal partial least squares model, namely, Staphylococcus, Candida, Weissella, Aspergillus, Zygosaccharomyces, Lactobacillus, Monilinia, and Clavispora. Correlation analysis showed that these microorganisms were strongly related to flavor metabolites. This study explored the dynamics of traditional Cantonese fermentation, which has positive implications for optimizing this traditional fermentation process.


Assuntos
Microbiota , Alimentos de Soja , Zygosaccharomyces , Aminoácidos/metabolismo , Fermentação , Fungos/metabolismo , Nitrogênio/metabolismo , Alimentos de Soja/análise , Zygosaccharomyces/metabolismo
5.
Food Microbiol ; 106: 104056, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35690450

RESUMO

This study aimed to investigate the formation and abatement strategies of biogenic amines (BAs) in the moromi contaminated accidently during Cantonese soy sauce (CSS) production processes. The ratio of total acid/amino nitrogen (TA/AAN) in koji can be used to predict the change in BAs content. Of the three main phases, BAs contents were more significantly increased once moromi manufacturing- and fermentation-phase were polluted. By co-culturing Tetragenococcus halophilus CGMCC3792 with Zygosaccharomyces rouxii CGMCC21865, BAs content was reduced by 59.96% and 51.10%, respectively, for the contaminated initial and fermenting moromi. Moreover, BAs content was reduced by 67.68% via the split batch fermentation method for the latter. Based on high throughput sequencing and metatranscriptome technology, BAs content was closely related to Lactobacillus abundance. It revealed the mechanism of abating BAs by inhibiting decarboxylase expression and changing redox potential. Therefore, it was an efficient strategy for abating BAs content and improving the flavor profile of CSS.


Assuntos
Alimentos de Soja , Zygosaccharomyces , Aminas Biogênicas/metabolismo , Enterococcaceae , Fermentação , Saccharomycetales , Zygosaccharomyces/genética
6.
Int J Food Microbiol ; 370: 109652, 2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35390573

RESUMO

Yeast plays an important role in the formation of desirable aroma during soy sauce fermentation. In this study, the structure and diversity of yeast communities in seven different soy sauce residues were investigated by ITS sequencing analysis, and then the aroma characteristics of selected yeast species were examined by a combination of gas chromatography-mass spectrometry (GC-MS), headspace solid-phase microextraction (SPME) and liquid-liquid extraction (LLE). A total of 18 yeast genera were identified in seven soy sauce residues. Among them, Candid and Zygosaccharomyces were detected in all samples, followed by Millerozyma, Wickerhamiella, Meyerozyma, Trichosporon and Wickerhamomyces, which were found in more than two-thirds of the samples. Subsequently, eight representative species, isolated from soy sauce residues, were subjected to environmental stress tolerance tests and aroma production tests. Among them, three isolated species were regarded as potential aroma-enhancing microbes in soy sauce. Wickerhamiella versatilis could increase the contents of ethyl ester compounds and alcohols, thereby improving the fruity and alcoholic aroma of soy sauce. Candida sorbosivorans enhanced sweet and caramel-like aroma of soy sauce by producing 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) and 3-hydroxy-2-methyl-4h-pyran-4-one (maltol). Starmerella etchellsii could enhance the contents of 2,6-dimethylpyrazine, methyl pyrazine and benzeneacetaldehyde. This study is of great significance for the development and application of flavor functional yeasts in soy sauce fermentation.


Assuntos
Alimentos de Soja , Zygosaccharomyces , Fermentação , Odorantes/análise , Alimentos de Soja/análise , Leveduras
7.
Int J Food Microbiol ; 367: 109589, 2022 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-35217292

RESUMO

This study aimed to evaluate the occurrence and diversity of yeasts in frozen concentrated orange juice (FCOJ) and assess the resistance of yeasts to peracetic acid. One thousand five hundred (n = 1500) samples of frozen concentrated orange juice (FCOJ) were analyzed, and 280 yeast strains were isolated and identified. Candida represented 37% of all isolates, and the main species identified were Candida pseudointermedia and C. orthopsilosis. Other yeasts identified were Starmerella, Wickerhamiella, Wickerhamiella, Clavispora, Kodamaea, Meyerozyma, Rhodotorula, Trichosporon, Wickerhamomyces, Kluyveromyces, Hanseniaspora, Saccharomyces, Torulaspora, and Zygosaccharomyces. The exogenous origin of the contamination in FCOJ samples analyzed was shown by the high diversity, corroborated by the Simpson (D) and Shannon (H') indices. From a total of 227 yeasts strains tested, more than 20% were able to withstand peracetic acid concentrations >200 ppm, with emphasis on W. anomalus (300 ppm), W. sergipensis (350 ppm), C. rugopelliculosa (350 ppm), K. marxianus (450 ppm), C. parapsilosis (500 ppm), C. pseudointermedia (500 ppm), W. sorbosivorans (500 ppm), C. boleticola (600 ppm), S. cerevisiae (700 ppm) and C. orthopsilosis (750 ppm). This study adds novel data regarding the occurrence and diversity of yeasts present in FCOJ and their resistance to a chemical compound commonly employed in the sanitization of processing and distribution premises and vehicles. These findings are essential to support the development of measures for proper mitigation of contamination of orange juice towards reducing the risks of spoilage by yeasts during FCOJ transportation/storage or when FCOJ is used as an ingredient.


Assuntos
Citrus sinensis , Zygosaccharomyces , Sucos de Frutas e Vegetais , Ácido Peracético/farmacologia , Saccharomyces cerevisiae , Leveduras
8.
J Food Sci ; 87(3): 1197-1210, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35152410

RESUMO

Due to hydrophobicity, plant essential oil components trans-cinnamaldehyde and thymol exert broad-spectrum antimicrobial activities by interfering with the structures and functions of microbial cell membranes, yet their antifungal properties against food-spoilage yeast Zygosaccharomyces rouxii are still unclear. This work aimed to elucidate their antifungal activities and mechanisms against Z. rouxii. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) were measured using broth dilution method to evaluate the antifungal activities. Membrane permeability, potential and integrity, intracellular ATP content, and intracellular pH (pHin ) were determined, and membrane damage was observed by scanning electron microscope (SEM) to investigate the antifungal mechanisms. The MICs of trans-cinnamaldehyde and thymol were 0.3125 and 0.0625 mg/ml, respectively, and the MFCs were 1.25 and 0.125 mg/ml, respectively. Increased membrane permeability, membrane hyperpolarization, decreased membrane integrity, reduced intracellular ATP content, and lowered pHin were found after trans-cinnamaldehyde or thymol treatment at the MIC and MFC levels, and thymol exhibited more severe influence on cell membrane. SEM observation further confirmed that trans-cinnamaldehyde caused cell membrane shrinkage and invagination, while thymol resulted in perforation in cell membrane. These results suggest that trans-cinnamaldehyde and thymol exert anti-Z. rouxii activities by inducing cell membrane damage and subsequent intracellular homeostasis disruption. Cellular contents leakage and intracellular homeostasis disruption probably proceed more rapidly after thymol inducing perforation in the cell surface, thereby thymol exerting better anti-Z. rouxii activity. PRACTICAL APPLICATION: The addition of a small amount of thymol (0.125 mg/ml) is sufficient to effectively inhibit the growth of Z. rouxii in apple juice concentrate. Based on our previous work, the addition of thymol (0.125 mg/ml) in apple juice concentrate did not significantly affect the organoleptic property of the diluted apple juice (5°Brix) used for producing commercial apple juice products. Therefore, thymol is practical for application at the effective concentration (0.125 mg/ml) in apple juice concentrate.


Assuntos
Timol , Zygosaccharomyces , Acroleína/análogos & derivados , Antifúngicos/metabolismo , Antifúngicos/farmacologia , Saccharomyces cerevisiae , Saccharomycetales , Timol/farmacologia
9.
Food Microbiol ; 103: 103966, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35082083

RESUMO

Aspergillus oryzae and Zygosaccharomyces rouxii are the perquisites microorganisms in food fermentation due to the broad application prospects of their secondary metabolites. The co-culture strategy simulates the naturally occurring ecology by developing artificial microbial communities. This strategy has also been widely adopted to investigate the novel secondary metabolites. In the present study, the effects of co-culture on extracellular and intracellular secondary metabolites of fungi in liquid culture were investigated through UPLC-QTOF-MS. Notably, A. oryzae could significantly inhibit the growth of Z. rouxii when A. oryzae and Z. rouxii were co-cultured. The results further indicated that the co-culture of fungi could affect the secondary metabolites and produce various metabolic pathways. Overall, this study will provide insights into fungal interactions and cell metabolism mechanisms, contributing to supplementing and enriching the fermentation potential of fungi.


Assuntos
Aspergillus oryzae , Zygosaccharomyces , Técnicas de Cocultura , Fermentação , Metabolômica
10.
Yeast ; 39(1-2): 141-155, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34957597

RESUMO

Breweries produce an increasing selection of beer and nonbeer beverages. Yeast and filamentous fungi may compromise quality and safety of these products in several ways. Recent studies on fungal communities in breweries are scarce and mostly conducted with culture-dependent methods. We explored fungal diversity in the production of alcoholic and nonalcoholic beverages in four breweries. Samples were taken for next generation sequencing (NGS) at the key contamination sites in 10 filling lines. Moreover, fungal isolates were identified in 68 quality control samples taken from raw materials, filling line surfaces, air, and products. NGS gave a comprehensive view of fungal diversity on filling line surfaces. The surface-attached communities mainly contained ascomycetous fungi. Depending on the site, the dominant genera included Candida, Saccharomyces, Torulaspora, Zygosaccharomyces, Alternaria, Didymella, and Exophiala. Sanger sequencing revealed 28 and 27 species of yeast and filamentous fungi, respectively, among 91 isolates. The most common species Saccharomyces cerevisiae, Zygosaccharomyces rouxii, and Wickerhamomuces anomalus were detected throughout production. Filling line surface and air samples showed the greatest diversity of yeast and filamentous fungi, respectively. The isolates of the most common yeast genera Candida, Pichia, Saccharomyces, and Wickerhamomyces showed low spoilage abilities in carbonated, chemically preserved drinks but could grow in products with reduced hurdles. Preservative resistant yeasts were rare, belonging to the species Dekkera bruxellensis, Pichia manschurica, and Zygosaccharomyces bailii. Penicillium spp. were dominant filamentous fungi. The results of this study help to evaluate spoilage risks caused by fungal contaminants detected in breweries.


Assuntos
Fungos , Zygosaccharomyces , Cerveja , Microbiologia de Alimentos , Fungos/genética , Controle de Qualidade , Saccharomyces cerevisiae , Leveduras
11.
Food Res Int ; 150(Pt A): 110747, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34865765

RESUMO

In this study, the contributions of three strains and different coculture patterns to microbial community diversity and metabolites in the high-salt liquid-state fermentation (HLF) soy sauce moromi were investigated. A comparison of two strains of Zygosaccharomyces rouxii showed that strain QH-25 had a stronger ability to contribute metabolites, including both nonvolatile and volatile types, to the moromi than strain QH-1, except for volatile acids and ketones. Of the various fortification patterns tested, the content of metabolites was significantly increased by inoculating Z. rouxii QH-25 prior to C. versatilis, especially the content of volatiles, including ketones, esters, phenols, and alcohols, which increased 1.61-fold compared with those in the control sample; the contents of these components were increased 3.07-, 1.91-, 1.36-, and 1.22-fold, respectively. In particular, characteristic components such as ethyl octanoate, 4-hydroxy-2(or 5)-ethyl-5(or 2)-methyl-3(2H)-furanone (HEMF), 4-ethyl-2-methoxy-phenol (4-EG), and 3-methyl-1-butanol were increased 3.99-, 3.29-, 1.63-, and 0.70-fold, respectively. Redundancy analysis (RDA) showed that Staphylococcus, Zygosaccharomyces, and Candida were positively correlated with the unique components described above. In addition, the nodes of the interaction network between Zygosaccharomyces and Candida were increased, and the positive correlation of Zygosaccharomyces with Staphylococcus was enhanced by inoculating Z. rouxii prior to C. versatilis. These results suggested that the unique flavor of soy sauce was closely related to the metabolic characteristics of strains affiliated with Z. rouxii, whether cultured singly or cocultured with C. versatilis. This study also provided a reference method for determining the differences in community structure and metabolites between traditional techniques and modern processes for soy sauce fermentation.


Assuntos
Microbiota , Alimentos de Soja , Zygosaccharomyces , Técnicas de Cocultura , Saccharomyces cerevisiae , Alimentos de Soja/análise
12.
FEMS Yeast Res ; 21(8)2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34791177

RESUMO

Evolution has provided a vast diversity of yeasts that play fundamental roles in nature and society. This diversity is not limited to genotypically homogeneous species with natural interspecies hybrids and allodiploids that blur species boundaries frequently isolated. Thus, life cycle and the nature of breeding systems have profound effects on genome variation, shaping heterozygosity, genotype diversity and ploidy level. The apparent enrichment of hybrids in industry-related environments suggests that hybridization provides an adaptive route against stressors and creates interest in developing new hybrids for biotechnological uses. For example, in the Saccharomyces genus where regulatory circuits controlling cell identity, mating competence and meiosis commitment have been extensively studied, this body of knowledge is being used to combine interesting traits into synthetic F1 hybrids, to bypass F1 hybrid sterility and to dissect complex phenotypes by bulk segregant analysis. Although these aspects are less known in other industrially promising yeasts, advances in whole-genome sequencing and analysis are changing this and new insights are being gained, especially in the food-associated genera Zygosaccharomyces and Kluyveromyces. We discuss this new knowledge and highlight how deciphering cell identity circuits in these lineages will contribute significantly to identify the genetic determinants underpinning complex phenotypes and open new avenues for breeding programmes.


Assuntos
Kluyveromyces , Saccharomyces , Zygosaccharomyces , Animais , Hibridização Genética , Kluyveromyces/genética , Estágios do Ciclo de Vida , Zygosaccharomyces/genética
13.
Food Sci Technol Int ; 27(6): 485-498, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34487460

RESUMO

The optimal conditions for elaborating oil/water nanoemulsions of lemongrass (LG), cinnamon bark (CB) and cinnamon leaves (CL) essential oils and their antimicrobial activity against Zygosaccharomyces bailii at pH 4.00 were studied. The effect of the emulsification methodology on the physical stability and antimicrobial activity of the nanoemulsions were also evaluated. Furthermore, the sensory impact of nanoemulsions added to an apple juice was tested. LG and CL nanoemulsions were elaborated by ultrasonication and CB nanoemulsion, by high-speed homogenization. They were stable for at least 120 days at 25 °C. They exhibited antimicrobial activity against Z. bailii being CB the most effective since it showed the smallest MIC value (156.3 mg/l), followed by LG (468.8 mg/l) and CL (1250.0 mg/l). A slight increase in growth rate was observed due to ultrasonication. An additive interaction in relation to the inhibitory effect between LG and CB nanoemulsions against Z. bailii was observed. While nanoemulsions obtained would be used as natural antimicrobial agents in food and beverage products, only LG nanoemulsion at MIC concentration diluted was acceptable in juice showing the sensory impact of essential oils on foods.


Assuntos
Cymbopogon , Óleos Voláteis , Zygosaccharomyces , Cinnamomum zeylanicum , Emulsões , Óleos Voláteis/farmacologia , Saccharomycetales
14.
J Agric Food Chem ; 69(35): 10301-10310, 2021 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-34449211

RESUMO

Fatty acids have great effects on the maintenance of the cell membrane structure, cell viability, and cell metabolisms. In this study, we sought to elucidate the effects of exogenous fatty acids on the salt tolerance of food yeast Zygosaccharomyces rouxii. Results showed that Z. rouxii can grow by using exogenous fatty acids (C12:0, C14:0, C16:0, C16:1, C18:0, C18:1, and C18:2) as the sole carbon source. Four fatty acids (C12:0, C16:0, C16:1, and C18:1) can improve the salt tolerance of cells, enhance the formation of the cell biofilm, regulate the chemical compositions, restore growth in the presence of cerulenin, regulate the contents of membrane fatty acids, and control the expression of key genes in the fatty acid metabolism. Our results reveal that Z. rouxii can synthesize membrane fatty acids from exogenous fatty acids and the supplementation of these fatty acids can override the need for de novo fatty acid biosynthesis.


Assuntos
Zygosaccharomyces , Ácidos Graxos , Saccharomyces cerevisiae , Saccharomycetales , Tolerância ao Sal , Zygosaccharomyces/genética
15.
World J Microbiol Biotechnol ; 37(6): 96, 2021 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-33969449

RESUMO

Non-conventional yeasts refer to a huge and still poorly explored group of species alternative to the well-known model organism Saccharomyces cerevisiae. Among them, Zygosaccharomyces rouxii and the sister species Zygosaccharomyces bailii are infamous for spoiling food and beverages even in presence of several food preservatives. On the other hand, their capability to cope with a wide range of process conditions makes these yeasts very attractive factories (the so-called "ZygoFactories") for bio-converting substrates poorly permissive for the growth of other species. In balsamic vinegar Z. rouxii is the main yeast responsible for converting highly concentrated sugars into ethanol, with a preference for fructose over glucose (a trait called fructophily). Z. rouxii has also attracted much attention for the ability to release important flavor compounds, such as fusel alcohols and the derivatives of 4-hydroxyfuranone, which markedly contribute to fragrant and smoky aroma in soy sauce. While Z. rouxii was successfully proposed in brewing for producing low ethanol beer, Z. bailii is promising for lactic acid and bioethanol production. Recently, several research efforts exploited omics tools to pinpoint the genetic bases of distinctive traits in "ZygoFactories", like fructophily, tolerance to high concentrations of sugars, lactic acid and salt. Here, I provided an overview of Zygosaccharomyces industrially relevant phenotypes and summarized the most recent findings in disclosing their genetic bases. I suggest that the increasing number of genomes available for Z. rouxii and other Zygosaccharomyces relatives, combined with recently developed genetic engineering toolkits, will boost the applications of these yeasts in biotechnology and applied microbiology.


Assuntos
Microbiologia de Alimentos/métodos , Tecnologia de Alimentos/métodos , Zygosaccharomyces/fisiologia , Fermentação , Frutose/química , Engenharia Genética , Genoma Fúngico , Fenótipo , Zygosaccharomyces/genética
16.
Yeast ; 38(8): 471-479, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33811363

RESUMO

Zygosaccharomyces sp. is an industrially important yeast for the production traditional fermented foods in Japan. At present, however, there is no easy method for mating Zygosaccharomyces sp. strains in the laboratory; furthermore, little is known about the expression of mating-type-specific genes in this yeast. Here, mating was observed when Zygosaccharomyces sp. was subjected to nitrogen-starvation conditions. The expression of mating-type-specific genes, Zygo STE6 and Zygo MFα1, was induced under nitrogen-starvation conditions, as confirmed by lacZ reporter assay. This expression was mating-type-specific: Zygo STE6 was expressed specifically for mating-type a, whereas and Zygo MFα1 was expressed specifically for mating-type α. Yeast strains Zygosaccharomyces rouxii DL2 and DA2, derived from type strain Z. rouxii CBS732, did not show mating even under nitrogen-starvation conditions. Gene sequencing revealed that the Zygo STE12 in Z. rouxii CBS732 has a frameshift mutation. Under nitrogen starvation, mating was observed in both DL2 and DA2 transformed with the wild-type Zygo STE12. The expression of Zygo STE6 in Z. rouxii DL2 transformed with wild-type Zygo STE12 under nitrogen-starvation conditions was confirmed by lacZ reporter assay. Collectively, these results revealed that, under nitrogen-starvation conditions, Zygosaccharomyces sp. can mate and mating-type-specific genes are expressed. Furthermore, Zygo Ste12 is essential for both mating and the expression of mating-type-specific genes in Zygosaccharomyces sp.


Assuntos
Proteínas Fúngicas/genética , Regulação Fúngica da Expressão Gênica , Fator de Acasalamento/genética , Zygosaccharomyces/genética , Sequência de Aminoácidos , DNA Fúngico/genética , Expressão Gênica , Nitrogênio/metabolismo , Saccharomycetales/genética , Zygosaccharomyces/classificação , Zygosaccharomyces/metabolismo
17.
Appl Microbiol Biotechnol ; 105(1): 259-270, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33216160

RESUMO

Zygosaccharomyces rouxii plays important roles in the brewing process of fermented foods such as soy sauce, where salt stress is a frequently encountered condition. In this study, effect of heat preadaptation on salt tolerance of Z. rouxii and the protective mechanisms underlying heat preadaptation were investigated based on physiological and transcriptomic analyses. Results showed that cells subjected to heat preadaptation (37 °C, 90 min) prior to salt stress aroused many physiological responses, including maintaining cell surface smooth and intracellular pH level, increasing Na+/K+-ATPase activity. Cells subjected to heat preadaptation increased the amounts of unsaturated fatty acids (palmitoleic C16:1, oleic C18:1, linoleic C18:2) and decreased the amounts of saturated fatty acids (palmitic C16:0, stearic C18:0) which caused the unsaturation degree (unsaturated/saturated = U/S ratio) increased by 2.4 times when compared with cells without preadaptation under salt stress. Besides, salt stress led to increase in contents of 5 amino acids (valine, proline, threonine, glycine, and tyrosine) and decrease of 2 amino acids (serine and lysine). When comparing the cells pre-exposed to heat preadaptation followed by challenged with salt stress and the cells without preadaptation under salt stress, the serine, threonine, and lysine contents increased significantly. RNA sequencing revealed that the metabolic level of glycolysis by Z. rouxii was weakened, while the metabolic levels of the pentose phosphate pathway and the riboflavin were enhanced in cells during heat preadaptation. Results presented in this study may contribute to understand the bases of adaptive responses in Z. rouxii and rationalize its exploitation in industrial processes.Key points• Heat preadaptation can improve high salinity tolerance of Z. rouxii.• Combined physiological and transcriptomic analyses of heat preadaptation mechanisms.• Provide theoretical support for the application of Z. rouxii.


Assuntos
Zygosaccharomyces , Temperatura Alta , Saccharomycetales , Estresse Salino , Transcriptoma , Zygosaccharomyces/genética
18.
Sci Rep ; 10(1): 16550, 2020 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-33024226

RESUMO

Bactrocera tryoni (Froggatt), the Queensland fruit fly (Qfly), is a highly polyphagous tephritid fly that is widespread in Eastern Australia. Qfly physiology is closely linked with its fungal associates, with particular relationship between Qfly nutrition and yeast or yeast-like fungi. Despite animal-associated fungi typically occurring in multi-species communities, Qfly studies have predominately involved the culture and characterisation of single fungal isolates. Further, only two studies have investigated the fungal communities associated with Qfly, and both have used culture-dependant techniques that overlook non-culturable fungi and hence under-represent, and provide a biased interpretation of, the overall fungal community. In order to explore a potentially hidden fungal diversity and complexity within the Qfly mycobiome, we used culture-independent, high-throughput Illumina sequencing techniques to comprehensively, and holistically characterized the fungal community of Qfly larvae and overcome the culture bias. We collected larvae from a range of fruit hosts along the east coast of Australia, and all had a mycobiome dominated by ascomycetes. The most abundant fungal taxa belonged to the genera Pichia (43%), Candida (20%), Hanseniaspora (10%), Zygosaccharomyces (11%) and Penicillium (7%). We also characterized the fungal communities of fruit hosts, and found a strong degree of overlap between larvae and fruit host communities, suggesting that these communities are intimately inter-connected. Our data suggests that larval fungal communities are acquired from surrounding fruit flesh. It is likely that the physiological benefits of Qfly exposure to fungal communities is primarily due to consumption of these fungi, not through syntrophy/symbiosis between fungi and insect 'host'.


Assuntos
Frutas/microbiologia , Interações entre Hospedeiro e Microrganismos/fisiologia , Larva/microbiologia , Micobioma/fisiologia , Simbiose , Tephritidae/microbiologia , Animais , Ascomicetos/isolamento & purificação , Ascomicetos/fisiologia , Austrália , Candida/isolamento & purificação , Candida/fisiologia , Hanseniaspora/isolamento & purificação , Hanseniaspora/fisiologia , Penicillium/isolamento & purificação , Penicillium/fisiologia , Pichia/isolamento & purificação , Pichia/fisiologia , Zygosaccharomyces/isolamento & purificação , Zygosaccharomyces/fisiologia
19.
Int J Food Microbiol ; 332: 108771, 2020 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-32650062

RESUMO

In this research, anti-yeast activity of natamycin in apple juice inoculated with both Zygosaccharomyces rouxii and Z. bailii during the storage at different temperatures was investigated. For this purpose, a response surface methodology approach was used to test and optimize effects of some processing variables; storage time (1, 21 and 41 days), storage temperature (4, 12 and 20 °C), sodium benzoate as a positive control (0, 0.05 and 0.1%) and natamycin concentration (0, 30 and 60 mg/L) on several physicochemical and bioactive properties of the apple juice samples. The results showed that the natamycin performed a remarkable anti-yeast effect on Z. bailii rather than on Z. rouxii. The brix levels of the samples decreased and so the turbidity values increased significantly due to the yeast activity during the storage. Bioactive properties were also significantly affected by the natamycin which was also revealed to increase the antioxidant capacity of apple juice during storage. Using multiple response optimization technique, it was calculated that minimum yeast count (YC) values would occur at storage time = 38.64 and 40.9 days, storage temperature = 19.81 and 14.4 °C, sodium benzoate level (fixed to 0%) and natamycin concentration = 40 and 51.9 mg/L for the samples inoculated with Z. bailii and Z. rouxii, respectively. It was concluded that the bioactive properties of apple juice could be preserved by addition of natamycin which is suggested to be a natural inhibitor during the storage.


Assuntos
Antifúngicos/farmacologia , Conservação de Alimentos/métodos , Sucos de Frutas e Vegetais/microbiologia , Natamicina/farmacologia , Zygosaccharomyces/efeitos dos fármacos , Microbiologia de Alimentos , Malus/microbiologia , Temperatura , Fatores de Tempo , Zygosaccharomyces/crescimento & desenvolvimento
20.
Food Chem ; 329: 127118, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32512391

RESUMO

Sonication was applied to accelerate aroma formation and shorten fermentation time of soy sauce. Effects of sonication at 68 kHz on the aroma and aroma-producing Zygosaccharomyces rouxii and Tetragenococcus halophilus in moromis were investigated using sensory evaluation, SPME-GC-olfactometry/MS, viable cell counting and scanning electron microscopy. The sensory scores of caramel-like, fruity, alcoholic, floral, malty, smoky, sour and overall aroma in sonicated moromis were enhanced by 23.4%, 23.2%, 13.6%, 12.8%, 7.6%, 6.3%, 5.6% and 14.4%, respectively. Sensory scores of samples fermented for 90-180 days were higher than those of controls fermented for 180 days, suggesting that sonication could reduce fermentation time by 90 days. Thirty-four aroma-active compounds were detected from 85 volatile compounds in soy sauces. Sonication accelerated and elevated the formation of aroma compounds by chemical reactions. It also markedly increased the reproduction and cell permeability of both microorganisms in moromis, which favored the formation of aroma compounds by both strains.


Assuntos
Odorantes/análise , Alimentos de Soja/análise , Enterococcaceae , Fermentação , Cromatografia Gasosa-Espectrometria de Massas , Sonicação , Alimentos de Soja/microbiologia , Paladar , Zygosaccharomyces
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