Search results for "lactic acid"
showing 10 items of 660 documents
Extension of Tosela cheese shelf-life using non-starter lactic acid bacteria
2011
Six strains of non-starter lactic acid bacteria (NSLAB) were used to extend the shelf-life of the fresh cheese Tosèla manufactured with pasteurised cows’ milk. The acidification kinetics of three Lactobacillus paracasei, one Lactobacillus rhamnosus and two Streptococcus macedonicus were studied in synthetic milk medium. Lb. paracasei NdP78 and NdP88 and S. macedonicus NdP1 and PB14-1 showed an interesting acidifying capacity and were further characterised for growth in UHT milk and production of antimicrobial compounds. Lb. paracasei NdP78 and S. macedonicus NdP1 grew more than 2 log cycles in 6 h. Lb. paracasei NdP78 was also found to produce a bacteriocin-like inhibitory substance (BLIS) …
Giarraffa and Grossa di Spagna naturally fermented table olives: Effect of starter and probiotic cultures on chemical, microbiological and sensory tr…
2014
Abstract This work investigated on the effects of selected starters and of probiotic strains on the evolution of microbiota, on trend of volatile compounds and on the final sensorial traits of green table olives. The olives, belonging to Giarraffa and Grossa di Spagna cultivars, were processed according to Sicilian traditional method and the following samples were obtained: (1) un-inoculated spontaneous olives, control; (2) olives inoculated with probiotic Lactobacillus rhamnosus H25; (3) olives inoculated with commercial probiotic L. rhamnosus GG; (4) olives inoculated with Lactobacillus plantarum GC3 plus Lactobacillus paracasei BS21; and (5) olives inoculated with L. plantarum GC3 plus L…
An integrated technological approach to the selection of lactic acid bacteria of flour origin for sourdough production
2013
article i nfo Several lactic acid bacteria (LAB) were evaluated in situ for their potential in sourdough fermentation. The strains belonged to Lactobacillus plantarum, Lactobacillus sakei, Lactobacillus sanfranciscensis, Leuconostoc citreum, Leuconostoc mesenteroides, Leuconostoc pseudomesenteroides and Weissella cibaria. LAB were used, in individual inocula, to carry out the fermentation of γ-ray treated (sterile) flour and untreated commercial flour, in order to evaluate their performances both in the absence and presence of the native microbiota of flour. The pH and total titratable acidity (TTA) showed a strong and fast acidification of the experimental sourdough determined by W. cibari…
Kinetics of lactate fermentation and citrate bioconversion by LactococcusIactisssp.Iactisin batch culture
1993
The growth kinetics of Lactococcus lactis ssp. lactis were studied in batch culture in conditions of non-limiting lactose and the presence of citric acid. The control of pH modified growth and citrate metabolism but did not change the yield of acid formation. At controlled pH the growth rate was unaffected by citrate metabolism. Lactose was transformed to L-lactate and assay of the metabolic by-products showed some heterofermentation at the end of the growth of cultures with low growth rates. This heterofermentation was interpreted as a slowing down of glycolysis with activation of both the pyruvate formate lyase (PFL) and the pyruvate dehydrogenase complex (PDHC). Under these conditions th…
Biodiversity and dairy traits of indigenous milk lactic acid bacteria grown in presence of the main grape polyphenols
2020
ABSTRACT The present work was developed to select lactic acid bacteria (LAB) to be used as starter cultures in functional cheese production. The indigenous milk LAB populations were isolated from fermented raw ewes’ milks (four bulks) added with 0.5 mg/mL of nine polyphenols commonly found in winery by-products. After 48 h of fermentation, all milks were characterized by an increase of LAB levels of about 3–4 Log cycles. All different colonies were purified and characterized for the main physiological and biochemical traits and then differentiated genetically at strain level and identified. Ten species belonging to the LAB genera Lactobacillus, Streptococcus, Enterococcus, Leuconostoc and L…
Fast and green: Sustainable rapid-prototyping of microfluidic chips on polylactic acid substrates
2018
This paper reports novel ways to bond bio-based polylactic acid (PLA) substrates for the production of sustainable, single-use, microfluidic components. A laser-based, fast (minutes) fabrication process for multi-layer microfluidic devices in PLA was reported recently but in that report, demonstrator devices were bonded with adhesive tape, which significantly reduced the devices transparency. In this paper, we propose two novel ways to bond PLA substrates, which alleviate the need for adhesives, and enable optimal device transparency.
Influence of the early bacterial biofilms developed on vats made with seven wood types on PDO Vastedda della valle del Belìce cheese characteristics
2019
Early vat bacterial biofilms developed spontaneously through contact with whey have been characterized on seven wood types (Castanea sativa Miller, Cedrus libani, A. Rich., Prunus avium L., Fraxinus ornus L., Juglans regia L., Pinus nigra J.F. Arnold and Populus nigra L.). The present study aimed to evaluate the influence of these biofilms on the microbiological, chemical, physical and sensory characteristics of PDO Vastedda della valle del Belìce (VdB) cheese, processed traditionally from raw ewe's milk using wooden tools. To this purpose, the experimental cheeses after 15 d of refrigerated storage were examined. Lactic acid bacteria (LAB) populations dominated the microbial community of a…
Adverse drug reactions to antiretroviral medication
2009
Antiretroviral therapy has greatly improved prognosis of HIV infection, with a dramatic reduction of morbidity and mortality worldwide. Nevertheless, the condition is still a common cause of death in many underdeveloped countries, where effective treatment is not always unavailable. More than 20 drugs active against HIV are commercially available, which belong to one of four groups: nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, protease inhibitors, and fusion/entry inhibitors. In the near future new drugs are expected, including those of a novel group, the integrase inhibitors. To avoid viral resistance, combinations of the drugs must always b…
Is the acidity of ascitic fluid a reliable index in making the presumptive diagnosis of spontaneous bacterial peritonitis?
1986
Ascitic fluid pH and arterial-ascitic fluid pH gradient were compared to ascitic fluid polymorphonuclear cell count in 84 patients with cirrhotic ascites and in 12 with malignant ascites to assess their role as diagnostic tests for spontaneous bacterial peritonitis and to clarify the relationship between ascitic fluid pH and lactate. Ascitic fluid pH was significantly lower (pH 7.30) in spontaneous bacterial peritonitis (n = 18) and probable spontaneous bacterial peritonitis (n = 12) than in sterileascites (pH 7.41; n = 54). Since blood pH levels were not different in the presence of infection, arterial-ascitic fluid pH gradient was significantly higher in spontaneous bacterial peritonitis …
Compromised integrity of excised porcine intestinal epithelium obtained from the abattoir affects the outcome of in vitro particle uptake studies
2002
Excised porcine intestinal tissue obtained from the local abattoir was studied for its suitability to examine the uptake and transport of poly(lactic-co-glycolic acid) (PLGA) nanoparticles in Peyer's (PP) and non-Peyer's patch (NPP) tissue in vitro. Incubation of such tissue with fluorescent PLGA and polystyrene particles revealed negligible uptake into the intercellular space with no noticeable difference between PP and NPP tissue. Similarly, yeast cells, which were used as a positive control for selective uptake into PP tissue, were found in the subepithelial area of both PP and NPP tissue. Therefore we examined the morphological integrity of the tissue for the duration of the experiments…