93,095 research outputs found
Linking wine lactic acid bacteria diversity with wine aroma and flavour
No full textAbstract not availableMaria Stella Cappello, Giacomo Zapparoli, Antonio Logrieco, Eveline J Bartowsk
Diaporthe rudis Associated with Berry Rot of Postharvest Grapes in Italy.
No full textGrapes for Italian passito wine production are subject to fungal decay during postharvest processing (withering). In January 2018, decayed berries of Vitis vinifera ‘Nosiola’ were observed in bunches stored in a fruit-drying room in Valle dei Laghi, Provincia Autonoma di Trento (Italy). The bunches displayed single or few berries with brown to dark brown discolorations and solitary or rarely aggregated, erumpent, black ascomata in the skin. The incidence of bunches with symptomatic berries was approximately 5%. Twelve small pieces (about 10 mm2) of epidermal and mesocarp berry tissues were sterilized in 0.5% NaOCl for 2 min, rinsed once in sterile distilled water, and then placed on potato dextrose agar (PDA). After 4 days at 25°C in the dark, fungal colonies showed similar morphology resembling cultures of Diaporthe spp. (Udayanga et al. 2014). Single-spore isolation was carried out to obtain pure cultures. Two representatives of these cultures (P19 [= CBS 145104] and P10) were identified by morphological and molecular analysis. On PDA, after 7 days at 25°C, colonies showed flat, entire edges, whitish to grayish, fluffy aerial mycelium. The reverse colony was light brown to gray, with dark brown pigmentation in the center. Mycelial PDA plugs (2.5 mm2) were transferred to alfalfa stems on water agar (15 g of agar/liter) as described by Udayanga et al. (2014). Pycnidia on alfalfa stems were black, globose, and erumpent at maturity. Conidiophores were hyaline, cylindrical, smooth, branched, ampulliform, straight to sinuous, 18 to 40 × 2 to 2.5 μm. Conidiogenous cells were cylindrical, terminal, with slight tapering toward apex (0.5 to 1 μm diameter). α-Conidia were hyaline, smooth, ellipsoidal, biguttulate, 5.7 ± 0.7 μm long, and 2.3 ± 0.4 μm wide (n = 40). β-Conidia were not observed. Species identification was performed by amplification of internal transcribed spacers, translation elongation factor 1-α, histone H3, and β-tubulin gene sequences using ITS1/ITS4, EF728/EF986, CYLH3F/H3-1b, and Bt2a/Bt2b primers, respectively (Guarnaccia et al. 2018). BLAST analysis and phylogenetic analysis, constructed with MEGA 7.0 software using the neighbor-joining method (evolutionary distances using the Tajima–Nei method) from combined multilocus databases, identified the isolates as Diaporthe rudis. The gene sequences were deposited in GenBank (accession nos. MH447355, MH447356, MH457708, MH457709, and MK205427 to MK205430). Pathogenicity testing was performed on 120 healthy partially dehydrated grape berries (cultivar Nosiola) with intact pedicel, surface sterilized by immersion in 0.5% NaOCl and rinsed three times in sterile distilled water. Each berry was inoculated with a 106 conidia/ml suspension of both isolates by piercing using a sterile tip (wounded berry, n = 50) or pipetting onto the berry surface (unwounded berry, n = 50). The control (20 berries) was inoculated with sterile water by piercing and pipetting. All inoculated withered berries were incubated at 25°C for 7 days at 95% relative humidity (RH). High RH values (>90%) are reached during the natural withering process depending on seasonal weather conditions. Disease index (DI), calculated for four disease severity classes in percentage, where DI = [sum (class frequency × score of rating class)]/[(total number of berries) × 4] × 100, of wounded and unwounded berries was approximately 26 and 18%, respectively. The frequent presence of microcracks and wounds on berry skin, owing to dehydration, handling, and insects that favor the fungal colonization, could explain the high DI values observed in unwounded berries. Symptoms on the infected berries were similar to those observed in the fruit-drying room. There were no symptoms on the control berries. The fungus was reisolated from the infected berries, thus completing Koch’s postulates. Although D. rudis has been recovered from asymptomatic and symptomatic grapevine (cane and leaf spots) (Guarnaccia et al. 2018), this is the first report of the fungus causing rot on grape fruit. Recently, D. eres, together with Pestalotiopsis biciliata and Diplodia seriata, has been associated with fruit rot in withered grapes (Lorenzini and Zapparoli 2018). This finding indicates that D. rudis may contribute, together with other pathogenic fungi, to the decay of grapes during the withering. Such decay is a major concern for producers because it could have a negative impact on wine quality
Corretta acidificazione nel formaggio grana attraverso la valutazione degli zuccheri residui nella cagliata
No full textOccurrence and infection of Cladosporium, Fusarium, Epicoccum and Aureobasidium in withered rotten grapes during post-harvest dehydration
No full textFungi like Cladosporium, Fusarium, Epicoccum and Aureobasidium can occur on withered grapes causing spoilage of passito wine. There is little or no information on the pathogenic role of these fungi. This study describes the isolation, incidence and identification of several isolates from different withered rotten grapes. Representative isolates grouped in several phenotypes were identified by phylogenetic analysis of internal transcribed spacer, actin or elongation factor gene sequences. Isolates of Cladosporium and Fusarium were ascribed to different species, of these C. ramotenellum, C. halotolerans and F. graminearum were isolated from Vitis vinifera for the first time. All Epicoccum and Aureobasidium isolates belonged to E. nigrum and A. pullulans, respectively. Random amplified DNA polymorphism analysis showed high level of heterogenicity among Epicoccum and Fusarium isolates. Infection assays were carried out to evaluate infectivity in some strains under different withering conditions. Fusarium spp. strains had similar infectivity, while significant variability was observed among Cladosporium spp. and E. nigrum strains. A. pullulans resulted particularly infective. This study provided insights into the occurrence and infection of these fungi in fruit-drying rooms with important implications towards control management during the witherin
New records of Penicillium and Aspergillus from withered grapes in Italy, and description of Penicillium fructuariae-cellae sp. nov.
No full textPenicillium and Aspergillus are common pathogenic fungi of grapes, that occur frequently on withered berries used in the Italian passito wine production. Members of these genera isolated from withered grapes were identified using molecular and morphological approaches. The isolates were examined by amplification of internal transcribed spacer region, beta-tubulin, calmodulin and RNA polymerase II second largest subunit. Penicillium bilaiae, Aspergillus pallidofulvus and A. puulaauensis are reported for the first time from Vitis vinifera. Two Penicillium isolates showed a distinct phylogenetic position and different morphological characteristics from P. bissettii and P. vasconiae, the two most closely related species. These isolates are assigned to the new species Penicillium fructuariae-cellae, that is here described. An in vitro pathogenicity assay was carried out to evaluate the infectivity to grape berries by Penicillium and Aspergillus isolates recovered in this study. All examined isolates colonized the berries when artificially inoculated, but to a lesser extent than Botrytis cinerea. This suggests that these fungi may contribute, with other pathogenic species, to the onset of post-harvest diseases of grapes
Bio-molecular characterisation of indigenous Oenococcus oeni strains from Negroamaro wine
No full textThe variation in the coding capacity within Oenococcus oeni can have a significant impact on wine quality. The detection of several genes involved in important metabolic pathways (i.e. citrate, sulphur and arginine metabolisms) was performed on 10 indigenous O.oeni strains from Negroamaro wine, a red table wine (Apulia, Italy). These strains were selected from 95 isolates, collected during spontaneous malolactic fermentation, according to the results of an Amplified Fragment Length Polymorphism (AFLP) analysis. A total of 16 genes were screened, most (11) of which had never previously been assayed on O.oeni. All strains possessed 10 genes encoding enzymes such as malolactic enzyme (mleA), esterase (estA), citrate lyase (citD, citE and citF), citrate transporter (maeP), α-acetolactate decarboxylase (alsD), α- acetolactate synthase (alsS), S-adenosylmethionine synthase (metK) and cystathionine β-lyase (metC) and resulted negative in the detection of genes encoding cystathionine γ-lyase (metB), ornithine transcarbamylase (arcB) and carbamate kinase (arcC). The sequence of PCR fragments of 11 genes of a representative strain (ITEM 15929) was compared to those of three reference O.oeni strains. The indigenous strain was phylogenetically more similar to PSU-1 and ATCC BAA1163 than AWRI B429. This study describes new genetic markers useful for detecting the genetic potential of O.oeni strains to contribute to aroma production and for investigating the population structure of the species. © 2014 Elsevier Ltd
Genetic and phenotypic diversity of Saccharomyces sensu stricto strains isolated from Amarone wine
No full textIndividual yeast strains belonging to the Saccharomyces sensu stricto complex were isolated from Amarone wine produced in four cellars of the Valpolicella area (Italy) and characterized by conventional physiological tests and by RAPD-PCR and mtDNA restriction assays. Thirteen out of 20 strains were classified as Saccharomyces cerevisiae (ex S. cerevisiae p.r. cerevisiae and p.r. bayanus) and the remaining as Saccharomyces bayanus (ex S. cerevisiae p.r. uvarum). RAPD-PCR method proved to be a fast and reliable tool for identification of Saccharomyces sensu stricto strains and also gave intraspecific differentiation. Restriction analysis of mtDNA permitted to distinguish S. cerevisiae and S. bayanus species and to discern polymorphism among S. cerevisiae isolates. The assessment of the phenotypic diversity within the isolates by gas-chromatographic analysis of secondary fermentation products was explored. Small quantities of isobutanol were produced by most of the strains and higher amounts by some S. cerevisiae strains with phenotypes Gal- and Mel-; all S. bayanus strains produced low amounts of amilyc alcohols. From this study it appears that each winery owns particular strains, with different genetic and biochemical characteristics, selected by specific environmental pressures during the Amarone winemaking process carried out at low temperature in presence of high sugar content
A CTAB based method for the preparation of total protein extract of wine spoilage microrganisms for proteomic analysis
No full textMapping the proteome of microrganisms by 2D-electrophoresis is often a hard task, because many contaminants, e.g. polysaccharides of the cell wall and nucleic acid, can obstruct the pores of the IEF gel resulting in streaks and smears. A protocol based on the use of the cationic detergent cetyl trimethylammonium bromide (CTAB) and its salt-dependent solubility was developed. The cellulose-producing strain Gluconoacetobacter hansenii AAB0248 was resolved on 7cm Minigels in over 500 protein spots (a hundred more than with protocols reported in literature). The method was further employed for mapping the proteome of some acid adapted, wine spoilage microrganisms e.g. acetic acid bacteria and a yeast
Geophilus ungviculatus Daday 1889
No full text44. Geophilus ungviculatus Daday, 1889 (1) Geophilus ungviculatis [sic!] Daday, 1889: 145, pl. 5, figs. 32–33. (2) G. unguiculatus [sic!] Dad.: Attems, 1903 b: 235. (3) G. unguiculatus [sic!] Daday: Attems, 1929 a: 176. (4) Geophilus unguiculatus [sic!] Dad.: Kanellis, 1959: 12. (5) Geophilus ungviculatus Daday, 1889: Zapparoli, 2002: 105, Fig. 46. General distribution. Europe: Greece (Peloponnisos) (Zapparoli 2002; Minelli et al. 2006). Chorotype. Peloponnesian endemic (END). Records in Peloponnisos (Fig. 15). Ahaia: Patra (loc. typ.) (1, 2, 3, 4, 5). Ecological notes. No habitat data available. Remarks. The identity of this species and its presence in Peloponnisos need to be investigated further (see Bonato et al. 2013).Published as part of Simaiakis, Stylianos Michail, Akkari, Nesrine & Zapparoli, Marzio, 2016, The centipedes of Peloponnisos and first records of genus Eurygeophilus in the East Mediterranean (Myriapoda: Chilopoda), pp. 301-346 in Zootaxa 4061 (4) on page 339, DOI: 10.11646/zootaxa.4061.4.1, http://zenodo.org/record/26420
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