Search results for "Actic acid"
showing 10 items of 660 documents
An investigation of the bacteriocinogenic potential of lactic acid bacteria associated with wheat (triticum durum) kernels and non-conventional flours
2008
One hundred and thirty-seven lactic acid bacteria (LAB), previously isolated from wheat (Triticum durum) grains and non-conventional flour samples, were tested for the production of antibacterial substances. A total of 16 strains (5 Enterococcus faecium, 5 Enterococcus mundtii, 4 Pediococcus pentosaceus, 1 Lactobacillus coryniformis and 1 Lactococcus garvieae) were found to inhibit the growth of Listeria innocua. The antibacterial activities were preliminarily investigated for their general behaviour with proteolytic (proteinase K, protease B and trypsin), amylolytic (α-amylase) and lipolytic (lipase) enzymes, after heat treatment, and exposure to different pHs and ethanol concentrations. B…
Yeast-Bacteria Coinoculation
2019
Abstract Yeasts and lactic acid bacteria (LAB) coinoculation is the simultaneous, or close in time inoculation, of both types of microorganisms in winemaking. Coinoculation has been used mainly to early accomplish malolactic fermentation (MLF), employing generally the couples Oenococcus oeni/Saccharomyces cerevisiae and Lactobacillus plantarum/S. cerevisiae. Early completion of MLF decreases the overall vinification time, reduces the microbial spoilage risk, and even prevents the biogenic amines synthesis. LAB/yeasts coinoculation could be also used to increase the acidity of wines when inoculated in grape must, using sugar to synthesize lactic acid and producing ethanol diminution. Coinocu…
Retention of aroma compounds by lactic acid bacteria in model food media
2008
The interactions between aroma compounds and other particles in foods, particularly with macromolecules, have been greatly studied in order to better understand the binding of flavors in food matrices. Bacteria possess many macromolecules on their cellular surface that provide them surface properties which are involved in the physicochemical interactions between cells and interfaces. However, the interactions between bacteria and aroma compounds have not received so much attention despite the presence of bacteria in many fermented products. In order to study the retention of aroma compounds by bacteria, we have investigated the retention of esters by lactic acid bacteria with static headspa…
Biodiversity and technological potential of wild lactic acid bacteria from raw cows' milk
2009
To study lactic acid bacteria (LAB) biodiversity and to evaluate their potential for use in dairy applications, eight raw cows' milk batches were sampled from five dairy factories located in different areas of the Trentino region during winter and summer milkings. A total of 370 (Gram-positive and catalase-negative) isolates were first molecularly analysed by means of randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). After strain differentiation (124 profiles), LAB were genetically identified at species level. The most frequently isolated LAB were lactococci, enterococci and streptococci. Lactobacilli, leuconostocs and pediococci were found at low levels. All strains …
Anaerobic Reduction of Glycerol to Propanediol-1.3 by Lactobacillus brevis and Lactobacillus buchneri
1984
Summary Three strains of Lactobacillus brevis and one strain of Lactobacillus buchneri grew very poorly on glucose. Good growth was observed on glucose plus glycerol; while glucose was fermented to acetate or ethanol, lactate and CO 2 , glycerol was dehydrated to 3-hydroxypropanal and subsequently reduced to propanediol-1.3. Cell extracts of L. brevis and L. buchneri grown on glucose plus glycerol contained a B 12 -dependent glycerol dehydratase and a propanediol-1.3 dehydrogenase. Glycerol was not metabolized when used as the only substrate. Fructose as sole carbon source was partially reduced to mannitol. The joint fermentation of fructose and glycerol yielded propanediol-1.3 from glycero…
Lactobacillus tucceti sp. nov., a new lactic acid bacterium isolated from sausage
2006
Abstract Following the application of several molecular techniques strain R 19c, isolated from sausage by Reuter in 1970 and deposited at the DSMZ as Lactobacillus sp., has been identified as pertaining to a new species. It showed singular ISR- Dde I and ISR- Hae III profiles that allowed its differentiation from 68 lactic acid bacteria reference strains analyzed. Phylogenetic analysis based on 16S rRNA gene sequences places this strain in the genus Lactobacillus within the Lactobacillus alimentarius group. Species L. versmoldensis is the closest phylogenetic neighbor with 96.3% sequence similarity. DNA–DNA hybridization experiments confirmed the independent status at species level of this …
Application of MALDI-TOF-MS and nested SAPD-PCR for discrimination ofOenococcus oeniisolates at the strain level
2015
Oenococcus oeni is the most important lactic acid bacterium during vinification and is frequently used as a commercial starter culture for malolactic fermentation. Since different strains exhibit a high heterogeneity concerning wine-related physiological characteristics, reliable methods for their differentiation at the strain level are needed, especially for the development of starter cultures. Microbial identification by using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) has increased over the last few years. In the present study, we used MALDI-TOF-MS for the differentiation of 11 O. oeni isolates originating from 5 different wine-growing reg…
The contribution of P. acidilactici, L. plantarum, and L. curvatus starters and L-(+)-lactic acid to the acrylamide content and quality parameters of…
2017
Abstract Lactic acid bacteria (LAB) from spontaneous rye sourdough were isolated, identified, and characterized by their growth, acidification rate, and carbohydrate metabolism. The isolated LAB were used for production of rye sourdough, and the influence of sourdough on mixed rye - wheat bread quality and acrylamide formation was evaluated. In addition, comparative studies by using acidification with L-(+)-lactic acid for mixed rye – wheat bread production were performed. Isolated LAB (P. acidilactici, L. plantarum, L. curvatus) demonstrated versatile carbohydrate metabolism, grown at 30 °C and 37 °C, and acidic tolerance. When the isolated strains were used for rye sourdough production, t…
Antibacterial polypeptides of Lactobacillus species
1990
Twelve of 79 strains of the genus Lactobacillus, mainly isolated from plants or fermenting material, were found to inhibit at least one of the nine indicator strains of the species Lact. brevis, Pediococcus damnosus and Leucanostoc oenos. The antimicrobial activities from Lact. brevis B 37 and Lact. casei B 80 were caused by polypeptides detectable in the culture liquids. They are bacteriocins with a narrow antimicrobial spectrum. Brevicin 37 from Lact. brevis B 37 was active against many lactic acid bacteria and Nocardia corallina, whereas caseicin 80 from Lact. casei B 80 inhibits only one other strain of Lact. casei. Brevicin 37 is stable at 121dC, caseicin 80 is inactivated above 60dC, …
The effect of Pediococcus acidilactici and Lactobacillus sakei on biogenic amines formation and free amino acid profile in different lupin during fer…
2016
Abstract The effect of Pediococcus acidilactici and Lactobacillus sakei strains on biogenic amines (BAs) formation during submerged and solid state fermentation of Lupinus luteus and Lupinus angustifolius was analysed. The composition of lupin seeds was evaluated and the influence of fermentation on free amino acid (FAA) profile was investigated. The highest protein and carbohydrate contents were found in L. luteus var. ‘Vilciai’, the highest carbohydrate contents – in L. angustifolius hybrid lines No. 1701 and No. 1800, and fat – in L. angustifolius hybrid lines No. 1700, No. 1703 and No. 1734. The interaction between the fermentation method, the bacterial strains used and lupin varieties …