Search results for "Lactic Acid Bacteria"
showing 10 items of 148 documents
Influence of autochthonous microbiota on the sicilian wine producution
2014
Study of the biochemical composition and physico-chemistry of a protein-based food model of Parkia biglobosa
2022
In West Africa, the seed of the cowpea (Parkia biglobosa) is used in traditional pharmacopoeia and especially in human food as a condiment. This legume is very rich in proteins and lipids and remains a poorly exploited source of protein. Our thesis focuses on the valorization of Néré seeds for the development of new protein-rich products of plant origin as an alternative to the use of soybean as a basic ingredient. The objectives were : (i)biochemical and physicochemical characterization of protein isolates from Néré seed flour according to the extraction process, (ii) selection of proteolytic lactic acid bacteria capable of fermenting Néré juice, reducing anti-nutritional factors in order …
A Multivariate Approach to Study the Bacterial Diversity Associated to the Wooden Shelves Used for Aging Traditional Sicilian Cheeses.
2022
The present study was carried to correlate the microbial diversity of the biofilms developed on the wooden boards used for aging traditional Sicilian cheeses with cheese typology. To this end, the microbial diversity of the shelves in contact with the cheeses PDO Pecorino Siciliano, PDO Piacentinu Ennese, and TAP Caciocavallo Palermitano, during ripening, was evaluated by a multivariate statistical approach. The shelf biofilms of this study were previously analyzed for their microbial composition, but no correlation between biodiversity and cheese type was investigated. Canonical discriminant analysis confirmed a cheese typology effect on the microbial loads of the wooden shelves investigat…
Effect of the natural winemaking process applied at industrial level on the microbiological and chemical characteristics of wine.
2013
The composition of yeast and lactic acid bacteria (LAB) communities and the chemical evolution of the large-scale commercial vinification of Catarratto IGT Sicilia, carried out under the biological regime, was followed from grape harvest until bottling. Simultaneously to the maximum growth of yeasts, LAB counts reached high level of concentration (6-7 log CFU mL(-1)) during the first steps of the alcoholic fermentation. Yeast identification was determined applying different molecular methods. The highest species biodiversity was observed on grape and must samples taken soon after pressing. Saccharomyces cerevisiae was detected at dominant concentrations during the entire winemaking process.…
Lactic acid bacteria strains for bioprotection application with cells entrapment in biopolymeric matrices
2013
Among the various methods to control foodborne pathogenic and/or food spoilage microorganisms in food chain, bioprotective lactic acid bacteria (LAB) appear to be promising tools for food biopreservation. This collaborative study, between PAPC (Agrosup Dijon, University of Burgundy) and BioDyMIA (University Lyon1-Lyon Isara) laboratories, concerned the development of sodium alginate/sodium caseinate polymeric matrices intended to entrap LAB cells selected for their anti-Listeria spp. activity. First, 4 LAB strains from 19 LAB strains were selected for their anti-Listeria spp. activity: this screening was performed by the method of agar diffusion against three Listeria spp strains. Then, ant…
Codominance of Lactobacillus plantarum and obligate heterofermentative lactic acid bacteria during sourdough fermentation
2015
Fifteen sourdoughs produced in western Sicily (southern Italy) were analysed by classical methods for their chemico-physical characteristics and the levels of lactic acid bacteria (LAB). pH and total titratable acidity (TTA) were mostly in the range commonly reported for similar products produced in Italy, but the fermentation quotient (FQ) of the majority of samples was above 4.0, due to the low concentration of acetic acid estimated by high performance liquid chromatography (HPLC). Specific counts of LAB showed levels higher than 10(8) CFU g(-1) for many samples. The colonies representing various morphologies were isolated and, after the differentiation based on phenotypic characteristics…
A taxonomic survey of lactic acid bacteria isolated from wheat (Triticum durum) kernels and non-conventional flours
2007
In order to explore the correspondence between raw material- and mature sourdough-lactic acid bacterial (LAB) communities, 59 Italian wheat (Triticum durum) grain samples, one bran and six non-conventional flour samples were analyzed through a culture-dependent approach. The highest cell count by an agar medium specific for LAB was 2.16 log CFU/g. From about 2300 presumptive LAB (Gram-positive and catalase-negative) colonies collected, a total of 356 isolates were subjected to identification by a genetic polyphasic strategy consisting of RAPD-PCR analysis, partial 16S rRNA gene sequencing, species-specific and multiplex PCRs. The isolates were recognized as 137 strains belonging to Aerococc…
Rapid 96-well plates DNA extraction and sequencing procedures to identify genome-wide transposon insertion sites in a difficult to lyse bacterium: La…
2014
International audience; Random transposon mutagenesis followed by adequate screening methods is an unavoidable procedure to characterize genetics of bacterial adaptation to environmental changes. We have recently constructed a mutant library of Lactobacillus casei and we aimed to fully annotate it. However, we have observed that, for L. casei which is a difficult to lyse bacterium, methods used to identify the transposon insertion site in a few mutants (transposon rescue by restriction and recircularization or PCR-based methods) were not transposable for a larger number because they are too time-consuming and sometimes not reliable. Here, we describe a method for large-scale and reliable id…
Biodiversity and dairy traits of lactic acid bacteria from foliage of aromatic plants before and after dehydration process monitored by a smart senso…
2020
ABSTRACT The main hypothesis of this work was to evaluate the presence of lactic acid bacteria (LAB) intrinsically resistant to plant essential oils in sage (Salvia officinalis L.) and laurel (Laurus nobilis), for future applications in functional cheese production by addition of aromatic herbs. The effect of the drying process on the viability of LAB was evaluated with three biomass densities (3, 4 and 5 kg/m2). The drying densities did not affect weight loss, but influenced the levels of LAB of sage and laurel. A total of 10 different strains of Enterococcus faecium, Enterococcus mundtii, Enterococcus raffinosus and Leuconostoc mesenteroides were identified from laurel, while sage did not…
The spatial distribution of bacteria in Grana-cheese during ripening.
2012
The microbial composition and its spatial distribution of Grana Trentino, a hard Parmesan-like cheese, was determined, from vat milk to cheese. After cutting along the vertical axis of the cheese wheels, three layers were sampled diagonally across the cheese: under the cheese rind, an intermediate section and the cheese core. After two different ripening periods (9 and 18 months), the cheese samples were analysed using traditional culture dependent and culture independent methods. Milk samples were dominated by mesophilic and psychrophilic bacterial counts. Thermophilic bacteria (Lactobacillus helveticus) were found in high amounts in cooked whey and natural whey starter cultures. After 9 m…