Publications by authors named "Mariana Tristezza"

13 Publications

  • Page 1 of 1

New Insights into the Oenological Significance of : Impact of Selected Autochthonous Strains on the Volatile Profile of Apulian Wines.

Microorganisms 2020 Apr 26;8(5). Epub 2020 Apr 26.

CNR-Institute of Sciences of Food Production (ISPA), via Prov.le, Lecce-Monteroni, 73100 Lecce, Italy.

In this investigation, we explored the oenological significance of (syn. ) isolates from Apulian grape musts. Moreover, we provide the first evidence of the impact of different strains on the wine aromatic properties tested as monocultures. We described the diversity of strains isolated from grapes and the variability of 'volatile' phenotypes associated with this intraspecific variability. Thirty-three isolates were characterized at strain level by PCR-based approach and, among these, 16 strains were identified and then tested by microfermentation tests carried out in grape must. Analyzed strains were low producers of acetic acid and hydrogen sulphide, not able to decarboxylate a panel of representative amino acids, whereas they showed fructophilic character and significant glycerol production. Volatile profiles of produced wines were investigated by gas chromatography-mass spectrometry. The Odor Activity Values of all molecules were calculated and 12 compounds showed values above their odor thresholds. Two selected strains (35NC1 and 15PR1) could be considered as possible starter cultures since they were able to positively affect the sensory properties of obtained wine. This report firstly supplies evidence on the strain-specific impact of different strains on the final aroma of produced wines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/microorganisms8050628DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7285007PMC
April 2020

Exploitation of Prunus mahaleb fruit by fermentation with selected strains of Lactobacillus plantarum and Saccharomyces cerevisiae.

Food Microbiol 2019 Dec 8;84:103262. Epub 2019 Jul 8.

CNR, Institute of Sciences of Food Production (ISPA), via Prov.le Lecce-Monteroni, 73100, Lecce, Italy. Electronic address:

The organoleptic attributes of Prunus mahaleb, a fruit representing a new source of bioactive compounds, are so pronounced that it can be consider non-edible. This study was designed to evaluate the acceptance of P. mahaleb fruits after fermentation with different Saccharomyces cerevisiae and Lactobacillus plantarum protechnological strains. Four different bacterial and one yeast strains, as single or mixed starter formulation, were used to inoculate an aqueous suspension of P. mahaleb fruits. The fermented fruits and fermentation broths were subjected to physico-chemical characterization and the organoleptic properties of both samples were also assessed by a hedonic panel. The obtained results indicated that all the employed strains were able to grow and to ferment the matrix. However, the mixed starter FG69 + Li180-7 (L. plantarum/S. cerevisiae) had the best impact on sensory characteristics of P. mahaleb fruit and fermented medium. The adopted protocol allowed us to attain edible fruits and a new fermented non-dairy drink with valuable probiotic health-promoting properties. In our knowledge, this is the first study concerning the exploitation of P. mahaleb fruits. This investigation confirmed the potential of yeasts and lactic acid bacteria co-inoculation in the design of starter tailored for this kind of food applications.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fm.2019.103262DOI Listing
December 2019

Early Ongoing Speciation of Within the Grape Ecosystem Revealed by the Internal Variability Among the rDNA Operon Repeats.

Front Microbiol 2018 3;9:1687. Epub 2018 Aug 3.

Institute of Sciences of Food Production (ISPA), National Research Council (CNR), Lecce, Italy.

A yeast strain was isolated during a study on vineyard-associated yeast strains from Apulia in Southern Italy. ITS and LSU D1/D2 rDNA sequences showed this strain not to belong to any known species and was described as the type strain of , a close relative of . Several secondary peaks appeared in the sequences, suggesting internal heterogeneity among the copies of the rDNA. This hypothesis was tested by sequencing single clones of the marker region. The analyses showed different levels of variability throughout the operon with differences between the rRNA encoding genes and the internally transcribed regions. and share high frequency variants, i.e., variants frequently found in many clones, whereas there is a large variability of the low frequency polymorphisms, suggesting that the mechanism of homogenization is more active with the former than with the latter type of variation. These findings indicate that low frequency variants are detected in Sanger sequencing as secondary peaks whereas in Next Generation Sequencing (NGS) of metagenomics DNA would lead to an overestimate of the alpha diversity. For the first time in our knowledge, this investigation shed light on the variation of the copy number of the rDNA cistron during the yeast speciation process. These polymorphisms can be used to investigate on the processes occurring in these taxonomic markers during the separation of fungal species, it being a genetic process highly frequent in the complex microbial ecosystem existing in grape, must and wine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2018.01687DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6085423PMC
August 2018

Transcriptional Analysis of sp. Capable of Degrading Ochratoxin A.

Front Microbiol 2016 9;7:2162. Epub 2017 Jan 9.

Institute of Sciences of Food Production, National Research Council Bari, Italy.

Ochratoxin A (OTA) is a nephrotoxic and potentially carcinogenic mycotoxin produced by several species of and , contaminating grapes, wine and a variety of food products. We recently isolated from OTA contaminated soil vineyard a novel free-living strain of sp. , ITEM 17016, able to degrade OTA into the non-toxic catabolic product ochratoxin α. Biochemical studies suggested that the degradation reaction proceeds via peptide bond hydrolysis with phenylalanine (Phe) release. In order to identify genes responsible for OTA degradation we performed a differential gene expression analysis of ITEM 17016 grown in the presence or absence of the toxin. Among the differentially expressed genes, six peptidases up-regulated at 6 h were identified. The degrading activity of the carboxypeptidase PJ_1540 was confirmed in a heterologous system. The enrichment analysis for Gene Ontology terms confirmed that OTA degradation proceeds through peptidase activities and revealed the over-representation of pathways related to Phe catabolism. These results indicate that Phe may represent an energy source for this sp. strain and that OTA degrading reaction triggers the modulation of further catabolic activities.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2016.02162DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5220012PMC
January 2017

The Oenological Potential of Hanseniaspora uvarum in Simultaneous and Sequential Co-fermentation with Saccharomyces cerevisiae for Industrial Wine Production.

Front Microbiol 2016 9;7:670. Epub 2016 May 9.

Consiglio Nazionale delle Ricerche-Institute of Sciences of Food Production Lecce, Italy.

In oenology, the utilization of mixed starter cultures composed by Saccharomyces and non-Saccharomyces yeasts is an approach of growing importance for winemakers in order to enhance sensory quality and complexity of the final product without compromising the general quality and safety of the oenological products. In fact, several non-Saccharomyces yeasts are already commercialized as oenological starter cultures to be used in combination with Saccharomyces cerevisiae, while several others are the subject of various studies to evaluate their application. Our aim, in this study was to assess, for the first time, the oenological potential of H. uvarum in mixed cultures (co-inoculation) and sequential inoculation with S. cerevisiae for industrial wine production. Three previously characterized H. uvarum strains were separately used as multi-starter together with an autochthonous S. cerevisiae starter culture in lab-scale micro-vinification trials. On the basis of microbial development, fermentation kinetics and secondary compounds formation, the strain H. uvarum ITEM8795 was further selected and it was co- and sequentially inoculated, jointly with the S. cerevisiae starter, in a pilot scale wine production. The fermentation course and the quality of final product indicated that the co-inoculation was the better performing modality of inoculum. The above results were finally validated by performing an industrial scale vinification The mixed starter was able to successfully dominate the different stages of the fermentation process and the H. uvarum strain ITEM8795 contributed to increasing the wine organoleptic quality and to simultaneously reduce the volatile acidity. At the best of our knowledge, the present report is the first study regarding the utilization of a selected H. uvarum strain in multi-starter inoculation with S. cerevisiae for the industrial production of a wine. In addition, we demonstrated, at an industrial scale, the importance of non-Saccharomyces in the design of tailored starter cultures for typical wines.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2016.00670DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4860541PMC
May 2016

From grape berries to wine: population dynamics of cultivable yeasts associated to "Nero di Troia" autochthonous grape cultivar.

World J Microbiol Biotechnol 2016 Apr 29;32(4):59. Epub 2016 Feb 29.

Dipartimento di Scienze Agrarie, degli Alimenti e dell'Ambiente, Università di Foggia, Via Napoli 25, 71100, Foggia, Italy.

The aim of this work was to study the biodiversity of yeasts isolated from the autochthonous grape variety called "Uva di Troia", monitoring the natural diversity from the grape berries to wine during a vintage. Grapes were collected in vineyards from two different geographical areas and spontaneous alcoholic fermentations (AFs) were performed. Different restriction profiles of ITS-5.8S rDNA region, corresponding to Saccharomyces cerevisiae, Issatchenkia orientalis, Metschnikowia pulcherrima, Hanseniaspora uvarum, Candida zemplinina, Issatchenkia terricola, Kluyveromyces thermotolerans, Torulaspora delbrueckii, Metschnikowia chrysoperlae, Pichia fermentans, Hanseniaspora opuntiae and Hanseniaspora guilliermondii, were observed. The yeast occurrences varied significantly from both grape berries and grape juices, depending on the sampling location. Furthermore, samples collected at the end of AF revealed the great predominance of Saccharomyces cerevisiae, with a high intraspecific biodiversity. This is the first report on the population dynamics of 'cultivable' microbiota diversity of "Uva di Troia" cultivar from the grape to the corresponding wine ("Nero di Troia"), and more general for Southern Italian oenological productions, allowing us to provide the basis for an improved management of wine yeasts (with both non-Saccharomyces and Saccharomyces) for the production of typical wines with desired unique traits. A certain geographical-dependent variability has been reported, suggesting the need of local based formulation for autochthonous starter cultures, especially in the proportion of the different species/strains in the design of mixed microbial preparations.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11274-016-2017-4DOI Listing
April 2016

Biodegradation of Ochratoxin A by Bacterial Strains Isolated from Vineyard Soils.

Toxins (Basel) 2015 Nov 27;7(12):5079-93. Epub 2015 Nov 27.

Institute of Sciences of Food Production, National Research Council, Unit of Lecce, via Provinciale Lecce-Monteroni, Lecce 73100, Italy.

Ochratoxin A (OTA) is a mycotoxin with a main nephrotoxic activity contaminating several foodstuffs. In the present report, five soil samples collected from OTA-contaminated vineyards were screened to isolate microorganisms able to biodegrade OTA. When cultivated in OTA-supplemented medium, OTA was converted in OTα by 225 bacterial isolates. To reveal clonal relationships between isolates, molecular typing by using an automated rep-PCR system was carried out, thus showing the presence of 27 different strains (rep-PCR profiles). The 16S-rRNA gene sequence analysis of an isolate representative of each rep-PCR profiles indicated that they belonged to five bacterial genera, namely Pseudomonas, Leclercia, Pantoea, Enterobacter, and Acinetobacter. However, further evaluation of OTA-degrading activity by the 27 strains revealed that only Acinetobacter calcoaceticus strain 396.1 and Acinetobacter sp. strain neg1, consistently conserved the above property; their further characterization showed that they were able to convert 82% and 91% OTA into OTα in six days at 24 °C, respectively. The presence of OTα, as the unique OTA-degradation product was confirmed by LC-HRMS. This is the first report on OTA biodegradation by bacterial strains isolated from agricultural soils and carried out under aerobic conditions and moderate temperatures. These microorganisms might be used to detoxify OTA-contaminated feed and could be a new source of gene(s) for the development of a novel enzymatic detoxification system.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/toxins7124864DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4690114PMC
November 2015

Draft genome sequence of Acinetobacter sp. neg1 capable of degrading ochratoxin A.

FEMS Microbiol Lett 2015 Apr 18;362(7). Epub 2015 Jan 18.

Institute of Sciences of Food Production, National Research Council, Bari, 70126, Italy

Ochratoxin A (OTA) is a nephrotoxic and potentially carcinogenic mycotoxin produced by several species of Aspergillus and Penicillium. It is one of the major mycotoxins contaminating grain, grapes and a variety of food products, and the development of methods for reducing pre- and post-harvest contamination has drawn considerable attention. In the current study, we isolated and sequenced the genome of a novel free-living Acinetobacter strain able to degrade OTA. Biochemical studies suggest that the degradation reaction proceeds via peptide bond hydrolysis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/femsle/fnv004DOI Listing
April 2015

Molecular and Technological Characterization of Saccharomyces cerevisiae Strains Isolated from Natural Fermentation of Susumaniello Grape Must in Apulia, Southern Italy.

Int J Microbiol 2014 9;2014:897428. Epub 2014 Jan 9.

C.N.R.-Istituto di Scienze delle Produzioni Alimentari, Unità Operativa di Lecce, Via Provinciale Lecce-Monteroni, 73100 Lecce, Italy.

The characterization of autochthonous Saccharomyces cerevisiae strains is an important step towards the conservation and employment of microbial biodiversity. The utilization of selected autochthonous yeast strains would be a powerful tool to enhance the organoleptic and sensory properties of typical regional wines. In fact, indigenous yeasts are better tailored to a particular must and because of this they are able to praise the peculiarities of the derived wine. The present study described the biodiversity of indigenous S. cerevisiae strains isolated from natural must fermentations of an ancient and recently rediscovered Apulian grape cultivar, denoted as "Susumaniello." The yeast strains denoted by the best oenological and technological features were identified and their fermentative performances were tested by either laboratory assay. Five yeast strains showed that they could be excellent candidates for the production of industrial starter cultures, since they dominated the fermentation process and produced wines characterized by peculiar oenological and organoleptic features.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2014/897428DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3942102PMC
March 2014

Biodiversity and safety aspects of yeast strains characterized from vineyards and spontaneous fermentations in the Apulia Region, Italy.

Food Microbiol 2013 Dec 16;36(2):335-42. Epub 2013 Jul 16.

CNR-Institute of Sciences of Food Production (ISPA), Operative Unit of Lecce, Lecce, Italy.

This work is the first large-scale study on vineyard-associated yeast strains from Apulia (Southern Italy). Yeasts were identified by Internal Transcribed Spacer (ITS) ribotyping and bioinformatic analysis. The polymorphism of interdelta elements was used to differentiate Saccharomyces cerevisiae strains. Twenty different species belonging to 9 genera were identified. Predominant on the grape surface were Metschnikowia pulcherrima, Hanseniaspora uvarum and Aureobasidium pullulans, whereas M. pulcherrima and H. uvarum were dominant in the early fermentation stage. A total of 692 S. cerevisiae isolates were identified and a number of S. cerevisiae strains, ranging from 26 to 55, was detected in each of the eight fermentations. The strains were tested for biogenic amines (BAs) production, either in synthetic media or grape must. Two Pichia manshurica, an Issatchenkia terricola and a M. pulcherrima strains were able to produce histamine and cadaverine, during must fermentation. The production of BAs in wine must was different than that observed in the synthetic medium. This feature indicate the importance of an "in grape must" assessment of BAs producing yeast. Overall, our results suggest the importance of microbiological control during wine-making to reduce the potential health risk for consumer represented by these spoilage yeasts.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.fm.2013.07.001DOI Listing
December 2013

Autochthonous fermentation starters for the industrial production of Negroamaro wines.

J Ind Microbiol Biotechnol 2012 Jan 21;39(1):81-92. Epub 2011 Jun 21.

C.N.R. Institute of Sciences of Food Production (ISPA), Operative Unit of Lecce, via Provinciale Lecce-Monteroni, 73100, Lecce, Italy.

The aim of the present study was to establish a new procedure for the oenological selection of Saccharomyces cerevisiae strains isolated from natural must fermentations of an important Italian grape cultivar, denoted as "Negroamaro". For this purpose, 108 S. cerevisiae strains were selected as they did not produce H(2)S and then assayed by microfermentation tests. The adopted procedure made it possible to identify 10 strains that were low producers of acetic acid and hydrogen sulphide and showed that they completed sugar consumption during fermentation. These strains were characterized for their specific oenological and technological properties and, two of them, strains 6993 and 6920, are good candidates as industrial starter cultures. A novel protocol was set up for their biomass production and they were employed for industrial-scale fermentation in two industrial cellars. The two strains successfully dominated the fermentation process and contributed to increasing the wines' organoleptic quality. The proposed procedure could be very effective for selecting "company-specific" yeast strains, ideal for the production of typical regional wines. "Winery" starter cultures could be produced on request in a small plant just before or during the vintage season and distributed as a fresh liquid concentrate culture.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10295-011-1002-zDOI Listing
January 2012

An optimized procedure for the enological selection of non-Saccharomyces starter cultures.

Antonie Van Leeuwenhoek 2011 Feb 24;99(2):189-200. Epub 2010 Jun 24.

CNR-Institute of Sciences of Food Production (ISPA), Operative Unit of Lecce, via Provinciale Lecce-Monteroni, Lecce, Italy.

The apiculate yeasts are the species predominating the first stage of grape must alcoholic fermentation and are important for the production of desired volatile compounds. The aim of the present investigation was to establish a protocol for the enological selection of non-Saccharomyces strains directly isolated from a natural must fermentation during the tumultuous phase. At this scope, fifty Hanseniaspora uvarum isolates were characterized at strain level by employing a new combined PCR-based approach. One isolate representative of each identified strain was used in fermentation assays to assess strain-specific enological properties. The chemical analysis indicated that all the analyzed strains were low producers of acetic acid and hydrogen sulphide, whereas they showed fructophilic character and high glycerol production. Analysis of volatile compounds indicated that one strain could positively affect, during the alcoholic fermentation process, the taste and flavour of alcoholic beverages. The statistical evaluation of obtained results indicated that the selected autochthonous H. uvarum strain possessed physiological and technological properties which satisfy the criteria indicated for non-Saccharomyces wine yeasts selection. Our data suggest that the described protocol could be advantageously applied for the selection of non-Saccharomyces strains suitable for the formulation of mixed or sequential starters together with Saccharomyces cerevisiae.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s10482-010-9475-8DOI Listing
February 2011

An optimized protocol for the production of interdelta markers in Saccharomyces cerevisiae by using capillary electrophoresis.

J Microbiol Methods 2009 Sep 22;78(3):286-91. Epub 2009 Jun 22.

C.N.R.-Institute of Sciences of Food Production (ISPA), Operative Unit of Lecce, via Provinciale Lecce-Monteroni, 73100 Lecce, Italy.

The amplification of genomic sequence blocks flanked by delta elements of retrotransposon origin has proved to be a very convenient method for molecular characterization of Saccharomyces cerevisiae strains. Fluorescent automated capillary electrophoresis (CE) was used to detect interdelta marker (IDM) patterns in S. cerevisiae, using the ABI Prism 3130 Genetic Analyzer. Main experimental parameters were studied and the optimal conditions for IDM amplification and samples run on the CE apparatus were determined. Fingerprints from fluorescent-labelled IDM produced using CE with the same sample analyzed by agarose electrophoresis (AE) were compared. The CE analysis was able to distinguish 43 different IDM profiles among 45 S. cerevisiae isolates with a discriminating capacity of 99.8%, whereas the AE analysis of the same samples allowed the identification of 27 different patterns (discriminatory power equal to 96%). Detection of fluorescent IDM was fast and reliable, and it facilitated data comparison. For the first time in our knowledge, the fluorescent CE proved to be well suited for IDM fingerprinting. Moreover, it could be routinely applied for the molecular differentiation of S. cerevisiae strains.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.mimet.2009.06.012DOI Listing
September 2009