Rodriguez M.E.,Laboratorio Of Microbiologia Y Biotecnologia |
Rodriguez M.E.,CONICET |
Lopes C.A.,Laboratorio Of Microbiologia Y Biotecnologia |
Lopes C.A.,Laboratorio Of Microbiologia Agricola |
And 6 more authors.
International Journal of Food Microbiology | Year: 2010
The use of selected Saccharomyces and non-Saccharomyces strains as mixed starters in winemaking would have advantages over the traditional spontaneous fermentation, producing wines with predictable and desirable characteristics. The aim of this study was to evaluate the impact of metabolic interactions between Patagonian indigenous Saccharomyces cerevisiae MMf9 and β-glucosidase producer Candida pulcherrima V6 strains on alcoholic fermentation behaviour and wine aroma Three inoculation strategies, simultaneous, sequential and final, were assayed at laboratory-scale fermentations using Muscat d'Alexandrie grape juice as substrate. The fermentation and yeast growth kinetics as well as the physicochemical and the sensory quality of wine were evaluated. Results evidenced that the sequential inoculation is the most adequate strategy of strains combination. The kinetic behaviour of sequential fermentation was similar to a successful spontaneous fermentation and its wine showed differential aromatic quality as evidenced through PC analysis using physicochemical and aromatic composition data. This wine presented the highest total concentration of higher alcohol, esters and terpenols and the strongest fruity and floral aroma. © 2010 Elsevier B.V. All rights reserved.
Lutz M.C.,Laboratorio Of Microbiologia Y Biotecnologia |
Lutz M.C.,National University of Comahue |
Robiglio A.,Laboratorio Of Microbiologia Y Biotecnologia |
Robiglio A.,National University of Comahue |
And 6 more authors.
Acta Horticulturae | Year: 2011
To reduce the use of fungicides, biological control with yeasts has been proposed worldwide in recent years. In order to find antagonistic yeasts adapted to pear storage conditions (-1/0°C for 7 months), two isolation strategies were explored. In 2007 (strategy A), the yeasts were isolated from the surface of healthy fruits. Aliquots of the obtained suspensions were seeded on GPY agar and incubated at 26°C. In 2008 (strategy B), washes from healthy wounds after 150 days at 0°C were used to inoculate fresh pear wounds with Penicillium expansum. Yeasts were isolated from healthy wounds after 50 days of incubation in cold. From both A and B isolation strategies, one isolate from each yeast species was tested for antagonistic activity against P. expansum and Botrytis cinerea by in vivo (pear wounds at 0°C) and in vitro (dual cultures at 20°C) assays. By means of strategy A, six yeast species were identified. Among them, the best antagonists were A. pullulans and R. mucilaginosa, which reduced only P. expansum disease incidence (33%). From strategy B, five of six species obtained, Cryptococcus weringae, C. victoriae, Cystofilobasidium infirmominiatum, Rhodotorula laryngis and A. pullulans, showed the highest antagonistic activity against P. expansum; they completely controlled disease incidence at 100 days. Only Cryptococcus weringae and C. victoriae reduced incidence of B. cinerea (80%) at 100 days. Differences between in vivo and in vitro biocontrol assays were observed. In in vitro assays, all yeasts produced a greater growth inhibition of P. expansum than of B. cinerea. Strategy B was the most effective strategy for the selection of antagonistic yeasts for postharvest disease control.