1,721,085 research outputs found
Liquorilactobacillus Zheng et al. 2020VP
No full textThe genus Liquorilactobacillus comprises 13 species of rod-shaped Gram-positive, catalase-negative, homofermentative, and aerotolerant bacteria with validly published names. Most of the species are motile. Growth generally occurs in the 15-45 °C range, with optimum growth temperature in the 28-30 °C range. Many strains grow in a pH range of 4.5 to 8. Some species are moderately salt tolerant, growing in the presence of 5% (w/v) NaCl. The genome sizes range from 1.92 to 2.72 Mbp. Hexoses are almost exclusively fermented to lactic acid by the Embden-Meyerhof-Parnas pathway (homofermentative metabolism). Pentoses are not fermented, with the notable exception of L. vini, which is the only known lactic acid bacterium that can homoferment pentoses to lactic acid. Many strains of Liquorilactobacillus produce dextran from sucrose. Mostly isolated from diverse liquid sources, including water, water kefir, alcoholic beverages, and fermented plant materials.
DNA G+C content (mol%): 33.9-39.9
Type species: Liquorilactobacillus mali Zheng et al. 2020VP (basonym: Lactobacillus mali Carr and Davies 1970, emend. Kaneuchi et al. 1988
Fattori biotici ed abiotici che influenzano la formazione di amine biogene negli alimenti fermentati
No full textProduction of Biogenic Amines During the Ripening of “Pecorino Abruzzese” Cheese
No full textThe production of biogenic amines (BA) during the manufacturing and ripening of sheep milk Pecorino Abruzzese cheeses prepared from raw milk without starter culture (A) and from pasteurized milk with added starter (B) were compared. At the end of ripening (60 days), the total BA contents of cheeses of batches A and B were 697 and 1086 mg kg(-1), respectively; the dominant BA were different. Single isolates of enterococci, pseudomonads and Enterobacteriaceae were screened for their potential to produce BA. Qualitative tests indicated a large spread of BA-forming cultures among the members of the Enterobacteriaceae and lactic acid bacteria (LAB). Differences among the levels of BA produced in UHT milk by representative isolates of coliforms, Pseudomonas and LAB were observed in relation to the microbial group or the isolate. The results emphasize the need to improve the general hygienic conditions of Pecorino Abruzzese cheese manufacture and control the indigenous bacterial population. (c) 2005 Elsevier Ltd. All rights reserved.[...
Gli starter microbici
No full textGli starter microbici (o colture starter) rappresentano la principale soluzione per la gestione dei microrganismi necessari alla produzione di alimenti e bevande fermentate. Allo scopo di inquadrare il settore, è proposta una rassegna critica delle definizioni di starter microbico e un quadro generale dei criteri di classificazione. Accanto agli standard necessari per coniugare l’impiego di starter microbici e con la tutela della salute pubblica, il capitolo propone un paragrafo sulle tematiche dello screening e del design incentrato su biodiversità microbica, criteri di selezione e approcci di miglioramento. Sono riportati cenni relativamente alle fasi di produzione, formulazione e conservazione. La trattazione si conclude con un approfondimento relativo ai cosiddetti ‘starter autoctoni’
Studio eco-enologico di lieviti Saccharomyces dei vini Recioto e Amarone della Valpolicella
No full textA study on yeasts from valpolicella wines (Italy): identification and characterization of Saccharomyces sensu strictu strains by genetic and physiological methods
No full textSaccharomyces bayanus var. uvarum and Saccharomyces cerevisiae succession during spontaneous fermentations of Amarone and Recioto wines
No full textThis study was undertaken to evaluate the biodiversity of the indigenous Saccharomyces
sensu stricto population during traditional vinification processes of Recioto and
Amarone wines using molecular typing techniques. In total 109 isolates, collected from eight
wineries during spontaneous fermentations, were identified and characterised by conventional
tests and by molecular methods, i.e. PCR fingerprinting using the primer (GTG)5,
mtDNA restriction and karyotype analyses. Sixty per cent of the isolates were assigned to
Saccharomyces bayanus var. uvarum and 40% to Saccharomyces cerevisiae. A succession
between S. bayanus var. uvarum, which dominated the first fermentation, and S. cerevisiae,
which appeared after the wine drawing-off operation, was observed during a traditional
Amarone winemaking. An extensive polymorphism was found between the isolates, however
a few specific genetic biotypes prevailed in the different wineries. This ecotaxonomic survey
constitutes a basic step to safeguard and exploit the oenological potential of the yeast
biodiversity in the Recioto and Amarone wine ecosystems. Such biodiversity could be further
explored to correlate the genetic patterns of the isolates with oenologically useful characteristics,
with the ultimate goal to carry out selection programmes of typical strains of the
Valpolicella area
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