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Isabel Sá-correia - One of the best experts on this subject based on the ideXlab platform.

  • Physiological Genomics of the Highly Weak-Acid-Tolerant Food Spoilage Yeasts of Zygosaccharomyces Bailii sensu lato.
    Progress in molecular and subcellular biology, 2019
    Co-Authors: Margarida Palma, Isabel Sá-correia
    Abstract:

    Zygosaccharomyces Bailii and two closely related species, Z. paraBailii and Z. pseudoBailii (“Z. Bailii species complex”, “Z. Bailii sensu lato” or simply “Z. Bailii (s.l.)”), are frequently implicated in the spoilage of acidified preserved foods and beverages due to their tolerance to very high concentrations of weak acids used as food preservatives. The recent sequencing and annotation of these species’ genomes have clarified their genomic organization and phylogenetic relationship, which includes events of interspecies hybridization. Mechanistic insights into their adaptation and tolerance to weak acids (e.g., acetic and lactic acids) are also being revealed. Moreover, the potential of Z. Bailii (s.l.) to be used in industrial biotechnological processes as interesting cell factories for the production of organic acids, reduction of the ethanol content, increase of alcoholic beverages aroma complexity, as well as of genetic source for increasing weak acid resistance in yeast, is currently being considered. This chapter includes taxonomical, ecological, physiological, and biochemical aspects of Z. Bailii (s.l.). The focus is on the exploitation of physiological genomics approaches that are providing the indispensable holistic knowledge to guide the effective design of strategies to overcome food spoilage or the rational exploitation of these yeasts as promising cell factories.

  • Transcriptional profiling of Zygosaccharomyces Bailii early response to acetic acid or copper stress mediated by ZbHaa1
    Scientific reports, 2018
    Co-Authors: Miguel Antunes, Margarida Palma, Isabel Sá-correia
    Abstract:

    The non-conventional yeast species Zygosaccharomyces Bailii is remarkably tolerant to acetic acid, a highly important microbial inhibitory compound in Food Industry and Biotechnology. ZbHaa1 is the functional homologue of S. cerevisiae Haa1 and a bifunctional transcription factor able to modulate Z. Bailii adaptive response to acetic acid and copper stress. In this study, RNA-Seq was used to investigate genomic transcription changes in Z. Bailii during early response to sublethal concentrations of acetic acid (140 mM, pH 4.0) or copper (0.08 mM) and uncover the regulatory network activated by these stresses under ZbHaa1 control. Differentially expressed genes in response to acetic acid exposure (297) are mainly related with the tricarboxylic acid cycle, protein folding and stabilization and modulation of plasma membrane composition and cell wall architecture, 17 of which, directly or indirectly, ZbHaa1-dependent. Copper stress induced the differential expression of 190 genes mainly involved in the response to oxidative stress, 15 ZbHaa1-dependent. This study provides valuable mechanistic insights regarding Z. Bailii adaptation to acetic acid or copper stress, as well as useful information on transcription regulatory networks in pre-whole genome duplication (WGD) (Z. Bailii) and post-WGD (S. cerevisiae) yeast species, contributing to the understanding of transcriptional networks’ evolution in yeasts.

  • Adaptive Response and Tolerance to Acetic Acid in Saccharomyces cerevisiae and Zygosaccharomyces Bailii: A Physiological Genomics Perspective.
    Frontiers in microbiology, 2018
    Co-Authors: Margarida Palma, Joana F. Guerreiro, Isabel Sá-correia
    Abstract:

    Acetic acid is an important microbial growth inhibitor in the food industry; it is used as a preservative in foods and beverages and is produced during normal yeast metabolism in biotechnological processes. Acetic acid is also a major inhibitory compound present in lignocellulosic hydrolysates affecting the use of this promising carbon source for sustainable bioprocesses. Although the molecular mechanisms underlying Saccharomyces cerevisiae response and adaptation to acetic acid have been studied for years, only recently they have been examined in more detail in Zygosaccharomyces Bailii. However, due to its remarkable tolerance to acetic acid and other weak acids this yeast species is a major threat in the spoilage of acidic foods and beverages and considered as an interesting alternative cell factory in Biotechnology. This review paper emphasizes genome-wide strategies that are providing global insights into the molecular targets, signaling pathways and mechanisms behind S. cerevisiae and Z. Bailii tolerance to acetic acid, and extends this information to other weak acids whenever relevant. Such comprehensive perspective and the knowledge gathered in these two yeast species allowed the identification of candidate molecular targets, either for the design of effective strategies to overcome yeast spoilage in acidic foods and beverages, or for the rational genome engineering to construct more robust industrial strains. Examples of successful applications are provided.

  • Genome sequence of the highly weak-acid-tolerant Zygosaccharomyces Bailii IST302, amenable to genetic manipulations and physiological studies.
    FEMS yeast research, 2017
    Co-Authors: Margarida Palma, Martin Münsterkötter, João Peça, Ulrich Güldener, Isabel Sá-correia
    Abstract:

    Zygosaccharomyces Bailii is one of the most problematic spoilage yeast species found in the food and beverage industry particularly in acidic products, due to its exceptional resistance to weak acid stress. This article describes the annotation of the genome sequence of Z. Bailii IST302, a strain recently proven to be amenable to genetic manipulations and physiological studies. The work was based on the annotated genomes of strain ISA1307, an interspecies hybrid between Z. Bailii and a closely related species, and the Z. Bailii reference strain CLIB 213T. The resulting genome sequence of Z. Bailii IST302 is distributed through 105 scaffolds, comprising a total of 5142 genes and a size of 10.8 Mb. Contrasting with CLIB 213T, strain IST302 does not form cell aggregates, allowing its manipulation in the laboratory for genetic and physiological studies. Comparative cell cycle analysis with the haploid and diploid Saccharomyces cerevisiae strains BY4741 and BY4743, respectively, suggests that Z. Bailii IST302 is haploid. This is an additional trait that makes this strain attractive for the functional analysis of non-essential genes envisaging the elucidation of mechanisms underlying its high tolerance to weak acid food preservatives, or the investigation and exploitation of the potential of this resilient yeast species as cell factory.

  • Additional file 2: of The Zygosaccharomyces Bailii transcription factor Haa1 is required for acetic acid and copper stress responses suggesting subfunctionalization of the ancestral bifunctional protein Haa1/Cup2
    2017
    Co-Authors: Margarida Palma, Paulo Dias, Filipa Roque, Laura Luzia, Joana Guerreiro, Isabel Sá-correia
    Abstract:

    Nucleotide sequences of the Zygosaccharomyces Bailii IST302 genes studied. (PDF 105 kb

Cecília Leão - One of the best experts on this subject based on the ideXlab platform.

  • The fate of acetic acid during glucose co-metabolism by the spoilage yeast Zygosaccharomyces Bailii.
    PloS one, 2012
    Co-Authors: Fernando Rodrigues, Maria João Sousa, Manuela Côrte-real, Paula Ludovico, Helena Santos, Cecília Leão
    Abstract:

    Zygosaccharomyces Bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate medium, supporting the conclusion that biomass yield on each substrate is not affected by the presence of the other at pH 3.0 and 5.0, at least for the substrate concentrations examined. In vivo 13C-NMR spectroscopy studies showed that the gluconeogenic pathway is not operational and that [2−13C]acetate is metabolised via the Krebs cycle leading to the production of glutamate labelled on C2, C3 and C4. The incorporation of [U-14C]acetate in the cellular constituents resulted mainly in the labelling of the protein and lipid pools 51.5% and 31.5%, respectively. Overall, our data establish that glucose is metabolised primarily through the glycolytic pathway, and acetic acid is used as an additional source of acetyl-CoA both for lipid synthesis and the Krebs cycle. This study provides useful clues for the design of new strategies aimed at overcoming yeast spoilage in acidic, sugar-containing food environments. Moreover, the elucidation of the molecular basis underlying the resistance phenotype of Z. Bailii to acetic acid will have a potential impact on the improvement of the performance of S. cerevisiae industrial strains often exposed to acetic acid stress conditions, such as in wine and bioethanol production.

  • Isolation of an acetyl-CoA synthetase gene (ZbACS2) from Zygosaccharomyces Bailii.
    Yeast (Chichester England), 2004
    Co-Authors: Fernando Rodrigues, Anne-marie Zeeman, M. Helena Cardoso, Maria João Sousa, H. Yde Steensma, Manuela Côrte-real, Cecília Leão
    Abstract:

    A gene homologous to Saccharomyces cerevisiae ACS genes, coding for acetyl-CoA synthetase, has been cloned from the yeast Zygosaccharomyces Bailii ISA 1307, by using reverse genetic approaches. A probe obtained by PCR amplification from Z. Bailii DNA, using primers derived from two conserved regions of yeast ACS proteins, RIGAIHSVVF (ScAcs1p; 210-219) and RVDDVVNVSG (ScAcs1p; 574-583), was used for screening a Z. Bailii genomic library. Nine clones with partially overlapping inserts were isolated. The sequenced DNA fragment contains a complete ORF of 2027 bp (ZbACS2) and the deduced polypeptide shares significant homologies with the products of ACS2 genes from S. cerevisiae and Kluyveromyces lactis (81% and 82% identity and 84% and 89% similarity, respectively). Phylogenetic analysis shows that the sequence of Zbacs2 is more closely related to the sequences from Acs2 than to those from Acs1 proteins. Moreover, this analysis revealed that the gene duplication producing Acs1 and Acs2 proteins has occurred in the common ancestor of S. cerevisiae, K. lactis, Candida albicans, C. glabrata and Debaryomyces hansenii lineages. Additionally, the cloned gene allowed growth of S. cerevisiae Scacs2 null mutant, in medium containing glucose as the only carbon and energy source, indicating that it encodes a functional acetyl-CoA synthetase. Also, S. cerevisiae cells expressing ZbACS2 have a shorter lag time, in medium containing glucose (2%, w/v) plus acetic acid (0.1-0.35%, v/v). No differences in cell response to acetic acid stress were detected both by specific growth and death rates. The mode of regulation of ZbACS2 appears to be different from ScACS2 and KlACS2, being subject to repression by a glucose pulse in acetic acid-grown cells.

  • The Spoilage Yeast Zygosaccharomyces Bailii Forms Mitotic Spores: a Screening Method for Haploidization
    Applied and environmental microbiology, 2003
    Co-Authors: Fernando Rodrigues, Maria João Sousa, H. Yde Steensma, Manuela Côrte-real, Paula Ludovico, Cecília Leão
    Abstract:

    Zygosaccharomyces Bailii ISA 1307 and the type strain of this spoilage yeast show a diploid DNA content. Together with a rather peculiar life cycle in which mitotic but no meiotic spores appear to be formed, the diploid DNA content explains the observed difficulties in obtaining auxotrophic mutants. Mitotic chromosome loss induced by benomyl and selection on canavanine media resulted in three haploid strains of Z. Bailii. This new set of Z. Bailii strains allows the easy isolation of recessive mutants and is suitable for further molecular genetic studies.

  • Oxygen requirements of the food spoilage yeast Zygosaccharomyces Bailii in synthetic and complex media.
    Applied and environmental microbiology, 2001
    Co-Authors: Fernando Rodrigues, Manuela Côrte-real, Cecília Leão, Johannes P. Van Dijken, Jack T. Pronk
    Abstract:

    Most yeast species can ferment sugars to ethanol, but only a few can grow in the complete absence of oxygen. Oxygen availability might, therefore, be a key parameter in spoilage of food caused by fermentative yeasts. In this study, the oxygen requirement and regulation of alcoholic fermentation were studied in batch cultures of the spoilage yeast Zygosaccharomyces Bailii at a constant pH, pH 3.0. In aerobic, glucose-grown cultures, Z. Bailii exhibited aerobic alcoholic fermentation similar to that of Saccharomyces cerevisiae and other Crabtree-positive yeasts. In anaerobic fermentor cultures grown on a synthetic medium supplemented with glucose, Tween 80, and ergosterol, S. cerevisiae exhibited rapid exponential growth. Growth of Z. Bailii under these conditions was extremely slow and linear. These linear growth kinetics indicate that cell proliferation of Z. Bailii in the anaerobic fermentors was limited by a constant, low rate of oxygen leakage into the system. Similar results were obtained with the facultatively fermentative yeast Candida utilis. When the same experimental setup was used for anaerobic cultivation, in complex YPD medium, Z. Bailii exhibited exponential growth and vigorous fermentation, indicating that a nutritional requirement for anaerobic growth was met by complex-medium components. Our results demonstrate that restriction of oxygen entry into foods and beverages, which are rich in nutrients, is not a promising strategy for preventing growth and gas formation by Z. Bailii. In contrast to the growth of Z. Bailii, anaerobic growth of S. cerevisiae on complex YPD medium was much slower than growth in synthetic medium, which probably reflected the superior tolerance of the former yeast to organic acids at low pH.

  • construction of a genomic library of the food spoilage yeast Zygosaccharomyces Bailii and isolation of the β isopropylmalate dehydrogenase gene zbleu2
    Fems Yeast Research, 2001
    Co-Authors: Fernando Rodrigues, Anne-marie Zeeman, Maria João Sousa, Manuela Cortereal, Cíntia Alves, Yde H Steensma, Cecília Leão
    Abstract:

    A genomic library of the yeast Zygosaccharomyces Bailii ISA 1307 was constructed in pRS316, a shuttle vector for Saccharomyces cerevisiae and Escherichia coli. The library has an average insert size of 6 kb and covers the genome more than 20 times assuming a genome size similar to that of S. cerevisiae. This new tool has been successfully used, by us and others, to isolate Z. Bailii genes. One example is the β-isopropylmalate dehydrogenase gene (ZbLEU2) of Z. Bailii, which was cloned by complementation of a leu2 mutation in S. cerevisiae. An open reading frame encoding a protein with a molecular mass of 38.7 kDa was found. The nucleotide sequence of ZbLEU2 and the deduced amino acid sequence showed a significant degree of identity to those of β-isopropylmalate dehydrogenases from several other yeast species. The sequence of ZbLEU2 has been deposited in the EMBL data library under accession number AJ292544.

Paola Branduardi - One of the best experts on this subject based on the ideXlab platform.

  • The spoilage yeast Zygosaccharomyces Bailii: Foe or friend?
    Yeast, 2017
    Co-Authors: Nurzhan Kuanyshev, Danilo Porro, Giusy Manuela Adamo, Paola Branduardi
    Abstract:

    Zygosaccharomyces Bailii is a non-Saccharomyces budding yeast known as one of the most aggressive food spoilage microorganisms, often isolated as a contaminant during wine fermentation, as well as from many acidic, high-sugar and canned foods. The spoilage ability relies on the yeast's unique feature of tolerating the most common preservatives such as sulphite, dimethyl dicarbonate, acetic acid and sorbic acid. Therefore, many studies have focused on the description of this peculiar tolerance with the aim of developing preventative measures against Z. Bailii food spoilage. These studies demonstrated the involvement of diverse molecular and physiological mechanisms in the yeast resistance, comprising detoxification of preservatives, adaptation of the cytoplasmic pH and modulation of the cell wall/membrane composition. At the same time, the described traits unveiled Z. Bailii as a novel potential workhorse for industrial bioprocesses. Here we present the yeast Z. Bailii starting from important aspects of its robustness and concluding with the exploitation of its potential in biotechnology. Overall, the article describes Z. Bailii from different perspectives, converging in presenting it as one of the most interesting species of the Saccharomycotina subphylum. Copyright © 2017 John Wiley & Sons, Ltd.

  • Assessing physio-macromolecular effects of lactic acid on Zygosaccharomyces Bailii cells during microaerobic fermentation.
    FEMS yeast research, 2016
    Co-Authors: Nurzhan Kuanyshev, Danilo Porro, Diletta Ami, Lorenzo Signori, John P. Morrissey, Paola Branduardi
    Abstract:

    The ability of Zygosaccharomyces Bailii to grow at low pH and in the presence of considerable amounts of weak organic acids, at lethal condition for Saccharomyces cerevisiae , increased the interest in the biotechnological potential of the yeast. To understand the mechanism of tolerance and growth effect of weak acids on Z. Bailii , we evaluated the physiological and macromolecular changes of the yeast exposed to sub lethal concentrations of lactic acid. Lactic acid represents one of the important commodity chemical which can be produced by microbial fermentation. We assessed physiological effect of lactic acid by bioreactor fermentation using synthetic media at low pH in the presence of lactic acid. Samples collected from bioreactors were stained with propidium iodide (PI) which revealed that, despite lactic acid negatively influence the growth rate, the number of PI positive cells is similar to that of the control. Moreover, we have performed Fourier Transform Infra-Red (FTIR) microspectroscopy analysis on intact cells of the same samples. This technique has been never applied before to study Z. Bailii under this condition. The analyses revealed lactic acid induced macromolecular changes in the overall cellular protein secondary structures, and alterations of cell wall and membrane physico-chemical properties.

  • Molecular tools and protocols for engineering the acid-tolerant yeast Zygosaccharomyces Bailii as a potential cell factory.
    Methods in molecular biology (Clifton N.J.), 2014
    Co-Authors: Paola Branduardi, Laura Dato, Danilo Porro
    Abstract:

    Microorganisms offer a tremendous potential as cell factories, and they are indeed used by humans for centuries for biotransformations. Among them, yeasts combine the advantage of unicellular state with a eukaryotic organization, and, in the era of biorefineries, their biodiversity can offer solutions to specific process constraints. Zygosaccharomyces Bailii, an ascomycetales budding yeast, is widely known for its peculiar tolerance to various stresses, among which are organic acids. 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 protocols for transformation, for target gene disruption or gene integration, and for designing episomal expression plasmids helpful for developing and further studying the yeast Z. Bailii.

  • Advances in molecular tools for the use of Zygosaccharomyces Bailii as host for biotechnological productions and construction of the first auxotrophic mutant
    FEMS yeast research, 2010
    Co-Authors: Laura Dato, Paola Branduardi, Minoska Valli, Simone Passolunghi, Davide Cattaneo, Luca Riboldi, Gianni Frascotti, Danilo Porro
    Abstract:

    The nonconventional yeast Zygosaccharomyces Bailii has been proposed as a new host for biotechnological processes due to convenient properties such as its resistance to high sugar concentrations, relatively high temperatures and especially to acidic environments. We describe a series of new expression vectors specific for Z. Bailii and the resulting improvements in production levels. By exploiting the sequences of the endogenous plasmid pSB2, 2microm-like multicopy vectors were obtained, giving a fivefold increase in production. A specific integrative vector was developed which led to 100% stability in the absence of selective pressure; a multiple-integration vector was constructed, based on an rRNA gene unit portion cloned and sequenced for this purpose, driving the insertion of up to 80 copies of the foreign construct. Moreover, we show the construction of the first stable auxotrophic mutant of Z. Bailii, obtained by targeted gene deletion applied to ZbLEU2. The development of molecular tools for the Z. Bailii manipulation has now reached a level that may be compatible with its industrial exploitation; the production of organic acids is a prominent field of application.

  • Investigating the multibudded and binucleate phenotype of the yeast Zygosaccharomyces Bailii growing on minimal medium
    FEMS yeast research, 2008
    Co-Authors: Laura Dato, Danilo Porro, Michael Sauer, Simone Passolunghi, Paola Branduardi
    Abstract:

    The yeast Zygosaccharomyces Bailii, known to have peculiar resistance to several environmental constraints, is very little known with respect to its genetics and life cycle. In addition to molecular and biochemical studies, cytofluorimetric and morphological analyses can also add information necessary to shed light on its interesting features. In the present study, the DNA and protein content as well as the cellular morphology of Z. Bailii populations growing in minimal medium supplemented with different carbon sources and with the addition of different organic acids were investigated. The results show the occurrence of a multibudded phenotype and of a low, but significant percentage of binucleate cells occurring in the early-stationary phase. These traits appear to be different in comparison with the better-known laboratory yeast Saccharomyces cerevisiae. Experiments and speculations about these features and possible implications with Z. Bailii main characteristics are discussed.

Danilo Porro - One of the best experts on this subject based on the ideXlab platform.

  • The spoilage yeast Zygosaccharomyces Bailii: Foe or friend?
    Yeast, 2017
    Co-Authors: Nurzhan Kuanyshev, Danilo Porro, Giusy Manuela Adamo, Paola Branduardi
    Abstract:

    Zygosaccharomyces Bailii is a non-Saccharomyces budding yeast known as one of the most aggressive food spoilage microorganisms, often isolated as a contaminant during wine fermentation, as well as from many acidic, high-sugar and canned foods. The spoilage ability relies on the yeast's unique feature of tolerating the most common preservatives such as sulphite, dimethyl dicarbonate, acetic acid and sorbic acid. Therefore, many studies have focused on the description of this peculiar tolerance with the aim of developing preventative measures against Z. Bailii food spoilage. These studies demonstrated the involvement of diverse molecular and physiological mechanisms in the yeast resistance, comprising detoxification of preservatives, adaptation of the cytoplasmic pH and modulation of the cell wall/membrane composition. At the same time, the described traits unveiled Z. Bailii as a novel potential workhorse for industrial bioprocesses. Here we present the yeast Z. Bailii starting from important aspects of its robustness and concluding with the exploitation of its potential in biotechnology. Overall, the article describes Z. Bailii from different perspectives, converging in presenting it as one of the most interesting species of the Saccharomycotina subphylum. Copyright © 2017 John Wiley & Sons, Ltd.

  • Assessing physio-macromolecular effects of lactic acid on Zygosaccharomyces Bailii cells during microaerobic fermentation.
    FEMS yeast research, 2016
    Co-Authors: Nurzhan Kuanyshev, Danilo Porro, Diletta Ami, Lorenzo Signori, John P. Morrissey, Paola Branduardi
    Abstract:

    The ability of Zygosaccharomyces Bailii to grow at low pH and in the presence of considerable amounts of weak organic acids, at lethal condition for Saccharomyces cerevisiae , increased the interest in the biotechnological potential of the yeast. To understand the mechanism of tolerance and growth effect of weak acids on Z. Bailii , we evaluated the physiological and macromolecular changes of the yeast exposed to sub lethal concentrations of lactic acid. Lactic acid represents one of the important commodity chemical which can be produced by microbial fermentation. We assessed physiological effect of lactic acid by bioreactor fermentation using synthetic media at low pH in the presence of lactic acid. Samples collected from bioreactors were stained with propidium iodide (PI) which revealed that, despite lactic acid negatively influence the growth rate, the number of PI positive cells is similar to that of the control. Moreover, we have performed Fourier Transform Infra-Red (FTIR) microspectroscopy analysis on intact cells of the same samples. This technique has been never applied before to study Z. Bailii under this condition. The analyses revealed lactic acid induced macromolecular changes in the overall cellular protein secondary structures, and alterations of cell wall and membrane physico-chemical properties.

  • Molecular tools and protocols for engineering the acid-tolerant yeast Zygosaccharomyces Bailii as a potential cell factory.
    Methods in molecular biology (Clifton N.J.), 2014
    Co-Authors: Paola Branduardi, Laura Dato, Danilo Porro
    Abstract:

    Microorganisms offer a tremendous potential as cell factories, and they are indeed used by humans for centuries for biotransformations. Among them, yeasts combine the advantage of unicellular state with a eukaryotic organization, and, in the era of biorefineries, their biodiversity can offer solutions to specific process constraints. Zygosaccharomyces Bailii, an ascomycetales budding yeast, is widely known for its peculiar tolerance to various stresses, among which are organic acids. 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 protocols for transformation, for target gene disruption or gene integration, and for designing episomal expression plasmids helpful for developing and further studying the yeast Z. Bailii.

  • Advances in molecular tools for the use of Zygosaccharomyces Bailii as host for biotechnological productions and construction of the first auxotrophic mutant
    FEMS yeast research, 2010
    Co-Authors: Laura Dato, Paola Branduardi, Minoska Valli, Simone Passolunghi, Davide Cattaneo, Luca Riboldi, Gianni Frascotti, Danilo Porro
    Abstract:

    The nonconventional yeast Zygosaccharomyces Bailii has been proposed as a new host for biotechnological processes due to convenient properties such as its resistance to high sugar concentrations, relatively high temperatures and especially to acidic environments. We describe a series of new expression vectors specific for Z. Bailii and the resulting improvements in production levels. By exploiting the sequences of the endogenous plasmid pSB2, 2microm-like multicopy vectors were obtained, giving a fivefold increase in production. A specific integrative vector was developed which led to 100% stability in the absence of selective pressure; a multiple-integration vector was constructed, based on an rRNA gene unit portion cloned and sequenced for this purpose, driving the insertion of up to 80 copies of the foreign construct. Moreover, we show the construction of the first stable auxotrophic mutant of Z. Bailii, obtained by targeted gene deletion applied to ZbLEU2. The development of molecular tools for the Z. Bailii manipulation has now reached a level that may be compatible with its industrial exploitation; the production of organic acids is a prominent field of application.

  • Investigating the multibudded and binucleate phenotype of the yeast Zygosaccharomyces Bailii growing on minimal medium
    FEMS yeast research, 2008
    Co-Authors: Laura Dato, Danilo Porro, Michael Sauer, Simone Passolunghi, Paola Branduardi
    Abstract:

    The yeast Zygosaccharomyces Bailii, known to have peculiar resistance to several environmental constraints, is very little known with respect to its genetics and life cycle. In addition to molecular and biochemical studies, cytofluorimetric and morphological analyses can also add information necessary to shed light on its interesting features. In the present study, the DNA and protein content as well as the cellular morphology of Z. Bailii populations growing in minimal medium supplemented with different carbon sources and with the addition of different organic acids were investigated. The results show the occurrence of a multibudded phenotype and of a low, but significant percentage of binucleate cells occurring in the early-stationary phase. These traits appear to be different in comparison with the better-known laboratory yeast Saccharomyces cerevisiae. Experiments and speculations about these features and possible implications with Z. Bailii main characteristics are discussed.

María Fernanda Gliemmo - One of the best experts on this subject based on the ideXlab platform.

  • Effect of gellan gum, xylitol and natamycin on Zygosaccharomyces Bailii growth and rheological characteristics in low sugar content model systems.
    International journal of biological macromolecules, 2020
    Co-Authors: Laura Inés Schelegueda, Aldana L. Zalazar, María Fernanda Gliemmo, Elizeth Tania Herbas, Carmen A. Campos
    Abstract:

    Abstract This study evaluated the effect of some natural additives and the structure imparted by them on microbial growth and rheological characteristics in acidic model foods with reduced glycidic content. Systems were formulated using gellan gum, as gelling agent; xylitol, as aw depressor; and natamycin, as antimicrobial. Additive-free control systems were prepared. The pH was adjusted to 3.50 or 5.50 as required. Systems were inoculated with Zygosaccharomyces Bailii. The effect of additives alone and combined on Z. Bailii growth was studied. In some cases, the possible use of additives as yeast nutrients was evaluated. Furthermore, systems rheological characterization was performed. Additives and the structure given by gellan gum significantly affected yeast growth. Gellan gum initially slowed Z. Bailii development, but as storage progressed, it acted as yeast carbon source, promoting its growth. A similar trend was observed when xylitol effect was studied. Natamycin inhibited yeast growth in all systems assayed. Additives modified the rheological characteristics of the gels and this effect depended on gellan gum concentration and pH. Obtained results emphasize the importance of considering the different effects that additives and their combinations can exert on the growth of deteriorating microorganisms and on the physical characteristics of gels.

  • Data supporting the growth/no growth interface of Zygosaccharomyces Bailii in simulated acid sauces.
    Data in Brief, 2018
    Co-Authors: Aldana L. Zalazar, María Fernanda Gliemmo, Marcelo Soria
    Abstract:

    Abstract This article contains experimental data, images and methods for the growth/no growth interface of Zygosaccharomyces Bailii in simulated acid sauces. Mentioned data are related to the research article “Modeling growth/no growth interface of Zygosaccharomyces Bailii in simulated acid sauces as a function of natamycin, xanthan gum and sodium chloride concentrations” (Zalazar et al., 2018) [1]. The growth was assessed colorimetrically by using 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride and 2-methoxy-1,4-naphthoquinone as detection reagents. Furthermore, yeast growth was confirmed by plate count.

  • data supporting the growth no growth interface of Zygosaccharomyces Bailii in simulated acid sauces
    Data in Brief, 2018
    Co-Authors: Aldana L. Zalazar, María Fernanda Gliemmo, Marcelo Abel Soria, Carmen Adriana Campos
    Abstract:

    This article contains experimental data, images and methods for the growth/no growth interface of Zygosaccharomyces Bailii in simulated acid sauces. Mentioned data are related to the research article "Modeling growth/no growth interface of Zygosaccharomyces Bailii in simulated acid sauces as a function of natamycin, xanthan gum and sodium chloride concentrations" (Zalazar et al., 2018) [1]. The growth was assessed colorimetrically by using 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride and 2-methoxy-1,4-naphthoquinone as detection reagents. Furthermore, yeast growth was confirmed by plate count.

  • Effect of steviosides and potassium sorbate on the growth and thermal inactivation of Zygosaccharomyces Bailii in acidified model aqueous systems
    Lwt - Food Science and Technology, 2017
    Co-Authors: Laura Inés Schelegueda, Aldana L. Zalazar, María Fernanda Gliemmo, Victoria Mariel Hracek, Carmen A. Campos
    Abstract:

    Abstract Zygosaccharomyces Bailii growth and thermal inactivation curves were obtained in acidified aqueous systems, simulating low sugar products. Growth curves were fitted with Gompertz equation, while thermal inactivation curves were modeled using Baranyi equation. The parameters of the models were estimated and the effect of steviosides (EE) and potassium sorbate (KS) on the growth and survival of Z. Bailii was established. The addition of KS decreased Z. Bailii growth rate and increased its inactivation rate. The presence of EE promoted Z. Bailii growth and protected yeast from thermal treatment. The joint use of KS and EE decreased the growth and nullified the protective effect of the sweetener on thermal inactivation. Results allow the selection of the appropriate concentrations of EE and KS to ensure the microbiological stability of evaluated systems and contribute to the development of low sugar products.

  • Effect of aspartame and other additives on the growth and thermal inactivation of Zygosaccharomyces Bailii in acidified aqueous systems
    Food Research International, 2013
    Co-Authors: María Fernanda Gliemmo, Laura Inés Schelegueda, Lía N. Gerschenson, Carmen Adriana Campos
    Abstract:

    Abstract Growth and thermal inactivation curves were obtained for Zygosaccharomyces Bailii in acidified aqueous systems resembling low sugar products. Growth curves were modeled using Gompertz equation while thermal inactivation curves were fitted with the Baranyi equation. The parameters of the models were estimated and used to establish the effect of aspartame and other additives (sorbate, xylitol and glucose) on the growth and survival of Z. Bailii . Aspartame addition produced different effects on growth rate depending on the solute added and the potassium sorbate concentration. The joint use of xylitol and aspartame showed the lowest growth rates in the absence or in the presence of 0.005% w/w sorbate. Regardless of subinhibitory levels of KS, the addition of aspartame increased the population of the stationary phase of the systems containing glucose or xylitol, suggesting that Z. Bailii metabolizes aspartame. The use of aspartame increased the thermal inactivation rates of all systems. Glucose or xylitol addition to the system containing aspartame and sorbate increased the heat sensitivity of Z. Bailii . In the absence of sorbate, only glucose decreased the heat resistance of the yeast, whereas xylitol did not affect it. The results obtained highlight the importance of considering the effect of system composition when evaluating microbial stability of food systems.