Malolactic Fermentation Induced by Lactobacillus plantarum in Malbec Wines from Argentina

The current market requirements to obtain wines with enhanced complexity and varietal character proposethe finding of new microorganisms capable of driving the malolactic fermentation (MLF) and contributingto new and distinctive sensory profiles in wines. During MLF, malic acid naturally present in the must isconverted into lactic acid by a decarboxylation reaction driven by lactic acid bacteria. Recently, a newstrain of Lactobacillus plantarum suitable for MLF in high-pH wines was selected. This study evaluatesthe capacity of the L. plantarum V22 starter culture to complete MLF at laboratory and semi-industrialscale in different Malbec musts from Argentina. Malbec musts were co-inoculated with S. cerevisiae D254and L. plantarum V22 to conduct alcoholic fermentation and MLF respectively. Two groups of Malbecmusts were identified according to the ability of L. plantarum to consume malic acid. A first group, called“High Feasibility for MLF”, is characterised by the high viability of L. plantarum and the completion ofMLF. On the other hand, a second group was identified, termed “Partial Feasibility for MLF”, and ischaracterised by a decreased viability of L. plantarum and incomplete MLF. This study shows that thecapacity of L. plantarum to conduct MLF in Malbec musts is dependent on must composition, furthersuggesting that the evolution of pH during the fermentation process, rather than initial pH, is a criticalfactor affecting the successful completion of MLF

Yeast identification in grape juice concentrates from Argentina

Aims: The purpose of this study was to identify yeast species present in spoiled and unspoiled grape juice concentrates from Argentine industries. Methods and Results: Osmophilic and osmotolerant yeasts were isolated from spoiled – visually effervescent – and unspoiled – without any visible damage – grape juice concentrates by the spread‐plate technique in two culture media. Yeast identification was done by classical and molecular methods. Zygosaccharomyces rouxii was the only species isolated from spoiled grape juice concentrates. In unspoiled samples, five different species were identified: Z. rouxii was isolated at a higher frequency, followed in decreasing order by Saccharomyces cerevisiae, Schizosaccharomyces pombe, Pichia anomala and Kluyveromyces delphensis. Conclusions: Yeasts isolated from grape juice concentrates were characterized by a limited taxonomic diversity, where Z. rouxii was the main species isolated. Significance and Impact of the Study: Grape production in Argentina is mainly devoted to the industry where wine and grape juice concentrates represent major types of commercial products. Little information on common yeast contaminants is available for grape juice concentrates. This study constitutes the first report of osmophilic yeast species present in spoiled and unspoiled grape juice concentrates elaborated in Argentina.EEA MendozaFil: Combina, Mariana. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Daguerre, Claire. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Massera, Ariel Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mercado, Laura Analia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sturm, Maria Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Mendoza; ArgentinaFil: Ganga, M.A. Universidad de Santiago de Chile. Facultad Tecnológica. Departamento de Ciencia y Tecnología de los Alimentos; ChileFil: Martínez, C. Universidad de Santiago de Chile. Facultad Tecnológica. Departamento de Ciencia y Tecnología de los Alimentos; Chil

Identification of a yeast with maceration capacity and partial characterization of the extracellular carbohydrolases

Estudios previos demostraron que una levadura autóctona, aislada de frutas cítricas, produce extractos enzimáticos con capacidad macerante de tejidos vegetales (papa, mandioca). El objetivo del presente estudio fue identificar dicha levadura por métodos moleculares e identificar las actividades enzimáticas posiblemente involucradas en el proceso de maceración. La identificación de la levadura se realizó mediante amplificación de la región entre los genes 18S rRNA y 28S rRNA utilizando los primers ITS1 e ITS4, seguido de digestión con enzimas de restricción (Hinf I, Cfo I y Hae III). El fragmento amplificado, 5.8S-ITS rRNA, fue secuenciado para confirmar su identidad. La levadura fue identificada como Pichia anomala. En sobrenadantes de cultivo se detectaron dos isoenzimas con actividad de poligalacturonasa (PG) de tipo endo; no se detectó actividad de pectinliasa, pectatoliasa, pectinesterasa, celulasa ni xilanasa.Previous studies have demonstrated that enzymatic extracts from a wild-type yeast isolated from citrus fruit peels display macerating activity of plant tissues (i.e. potato, cassava, etc.). The aim of the present study was to identify the wild-type yeast by molecular methods and characterize the enzymatic activities possibly involved in the maceration process. Molecular identification of the wild-type yeast was performed by amplification of the 18S and 28S rRNA regions using ITS1 and ITS4 primers followed by digestion with restriction enzymes (Hinf I, Cfo I and Hae III). The species assignation was also confirmed by sequence analyses of the 5.8S-ITS rRNA region. The wild-type yeast was identified as Pichia anomala. Two isoenzymes with PG activity were found in culture supernatants, whereas cellulase, xylanase, pectinlyase, pectatelyase and pectinesterase activities were not detected.Centro de Investigación y Desarrollo en Fermentaciones Industriale

First record of Nopachtus coagmentatus (Xenarthra, Glyptodontidae) for the Catamarca Province, Argentina. Revision of the genus Nopachtus

Nopachtus coagmentatus fue reconocido por Ameghino en 1888. El holotipo procede de la Formación Brochero (Montehermosense - Chapadmalalense [Plioceno temprano - Plioceno tardío]), de las cercanías de Villa Cura Brochero (Córdoba). Se reporta el primer hallazgo de esta especie para la Provincia de Catamarca. Se describe el material hallado, se detalla su procedencia y se presenta el perfil estratigráfico detallado correspondiente. El material mencionado, procedente de la Formación Salicas aflorante en el paraje de Suri Yaco, consiste en 14 osteodermos de la coraza dorsal que se atribuyen a N. coagmentatus, 12 completos y 2 fragmentados correspondientes a la región media y póstero-dorsal de la coraza dorsal. Estos osteodermos presentan una figura central rodeada por dos hileras de figuritas periféricas y figuritas que corresponderían a una tercera hilera, siempre incompleta. La primera hilera tiene entre 10 y 12 figuritas y la segunda entre 19 y 22; las figuritas son pentagonales o, mayoritariamente, hexagonales. A su vez, se revisa todo el material hasta ahora conocido para este género, que incluye dos especies. Para N. coagmentatus solamente había dos registros fehacientes, hasta esta comunicación, y varios dudosos, en tanto que para N. cabrerai Zamorano, Scillato-Yané, González Ruiz & Zurita solo se dio a conocer el holotipo.Nopachtus coagmentatus was recognized by Ameghino in 1888. Holotype comes from Brochero Formation (Montehermosan - Chapadmalalan [early Pliocene - late Pliocene]), near to Villa Cura Brochero (Córdoba). First find of this species for the Catamarca Province is reported. Remains found are described, its provenance detailed and the corresponding stratigraphic log is presented. The mentioned material, came from Salicas Formation, cropping out in the paraje Suri Yaco, consists of 14 osteoderms of the dorsal region of the carapace attributed to N. coagmentatus, 12 complete and 2 fragmented corresponding to the media and posterodorsal region of the carapace. These osteoderms present a central figure surrounded by two row of peripheral figures, and figures that would correspond to a third row, always incomplete. The first row has between 10 and 12 figures and the second between 19 and 22; the figures are pentagonal or, mainly, hexagonal. In turn, all specimens known today for this genus, that included two species, is revised. Until this communication, only two reliable records, and several doubtful were recognized for N. coagmentatus; while for N. cabrerai Zamorano, Scillato-Yané, Gonzalez Ruiz & Zurita only the holotype was given to known.Facultad de Ciencias Naturales y Muse

Association between Grape Yeast Communities and the Vineyard Ecosystems

The grape yeast biota from several wine-producing areas, with distinct soil types and grapevine training systems, was assessed on five islands of Azores Archipelago, and differences in yeast communities composition associated with the geographic origin of the grapes were explored. Fifty-seven grape samples belonging to the Vitis vinifera grapevine cultivars Verdelho dos Acores (Verdelho), Arinto da Terceira (Arinto) and Terrantez do Pico (Terrantez) were collected in two consecutive years and 40 spontaneous fermentations were achieved. A total of 1710 yeast isolates were obtained from freshly crushed grapes and 1200 from final stage of fermentations. Twenty-eight species were identified, Hanseniaspura uvarum, Pichia terricola and Metschnikowia pulcherrima being the three most representative species isolated. Candida carpophila was encountered for the first time as an inhabitant of grape or wine-associated environments. In both sampling years, a higher proportion of H. uvarum in fresh grapes from Verdelho cultivar was observed, in comparison with Arinto cultivar. Qualitatively significant differences were found among yeast communities from several locations on five islands of the Archipelago, particularly in locations with distinctive agro-ecological compositions. Our results are in agreement with the statement that grape-associated microbial biogeography is non-randomly associated with interactions of climate, soil, cultivar, and vine training systems in vineyard ecosystems. Our observations strongly support a possible linkage between grape yeast and wine typicality, reinforcing the statement that different viti-cultural terroirs harbor distinctive yeast biota, in particular in vineyards with very distinctive environmental conditions.Joao Drumonde Neves is the recipient of a fellowship of the Azorean Government (M321/006/F/2008) and PROEMPREGO. This work was supported by the strategic programme UID/BIA/04050/2013 (POCI-01-0145-FEDER-007569) funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI), and by national funds through FCT by the projects FCOMP-01-0124-008775, PTDC/AGR-ALI/103392/2008 and PTDC/AGR-ALI/121062/2010.info:eu-repo/semantics/publishedVersio

Evaluation of the effectiveness of potential biocontrol yeasts against black sur rot and ochratoxin A occurring under greenhouse and field grape production conditions

The efficacy of two strains of Lanchancea thermotolerans in preventing the growth and ochratoxin A (OTA) accumulation of ochratoxigenic fungi under greenhouse and field conditions were evaluated during three consecutive year trials. The data from this study showed that both yeast strains were able to control Aspergillus section Nigri species ochratoxin A accumulation in wine grapes at harvest stage. The inhibitory effects were dependent on the ochratoxigenic species, yeast strains, and year analyzed. Over all conditions assayed, ochratoxin A accumulation was reduced from 27% to 100%, depending on the conditions evaluated. These results are promising for future development of a bio-pesticide.</p