Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “LACTIC ACID”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,747 records · Page 97Linked to original sources

Characterisation of lactic acid bacteria isolated from naturally fermented Greek dry salami.

A total of 348 lactic acid bacteria isolated from five batches of naturally fermented dry salami at various stages of ripening were characterised. The majority of the strains were assigned to two main phylogenetic groups of species: (i) the psychrotrophic, formerly called atypical, meat streptobacteria (169 strains) and (ii) a new genus Weissella (120), which was recently proposed (Collins et al., 1993) to include Leuconostoc paramesenteroides and some other closely related species. Meat streptobacteria were identified as Lactobacillus curvatus (88 strains) and L. sake (76), whereas 5 strains were indistinguishable and, thus designated L. sake/curvatus. Non-psychrotrophic streptobacteria were also isolated and identified as L. plantarum (34 strains), L. farciminis (10), L. coryniformis (1) and L. casei subsp. pseudoplantarum (1). The majority of the Weissella strains (86) were leuconostoc-like bacteria; four of them were identified as W. viridescens, 11 belonged to the newly described W. hellenica (Collins et al., 1993), another 11 resembled W. paramesenteroides, whereas 60 isolates were not classified to any species. The latter group comprised strains that produced D(L)-lactate. The remaining Weissella were gas-forming, arginine-positive rods assigned to W. minor (31) and W. halotolerans (3). Other species identified were Enterococcus faecium (10), Leuconostoc mesenteroides (1), L. brevis (1) and Pediococcus sp. (1). The main criteria used to distinguish between above species as well as their distribution on the five salami batches in relation to their succession with time and suitability as starters were discussed.

Animals↗

Biodiversity and identification of sourdough lactic acid bacteria.

This review deals with recent developments on the biodiversity of sourdough lactic acid bacteria (LAB) and the recent description of new sourdough LAB species. One of the outcomes of biodiversity studies of particular sourdough ecosystems throughout Europe is the description of new taxa of LAB. During the last 3 years, several new LAB species have been isolated from traditional sourdoughs: Lactobacillus mindensis, Lactobacillus spicheri, Lactobacillus rossiae, Lactobacillus zymae, Lactobacillus acidifarinae, Lactobacillus hammesii, and Lactobacillus nantensis. Some of these species have been described on one single isolate only. Isolation of novel taxa mainly depends on the cultivation approach used, i.e. (selective) incubation media and conditions. The distribution of the taxa of LAB is highly variable from one sourdough ecosystem to another. Therefore, it is difficult to define correlations between population composition and both the type of sourdough or the geographic location. Identification of isolated strains needs a polyphasic approach, including a combination of phenotypic and genotypic methods, the latter often based on the polymerase chain reaction (PCR) and encompassing 16S rRNA sequencing and DNA-DNA hybridizations. A main obstacle in current identification approaches of LAB strains is the lack of a robust and exchangeable identification system for all LAB species. Recent studies based on complete genomes have provided the basis for establishing sets of genes useful for multi-locus sequence analysis (MLSA). Monitoring the population dynamics of sourdough ecosystems can be performed by both culture-dependent (plating and incubation) and culture-independent (e.g. PCR-Denaturing Gradient Gel Electrophoresis) methods. Although highly valuable for community fingerprinting, culture-independent methods do not always yield precise quantitative information.

Biodiversity↗

Enzymatic activities of lactic acid bacteria isolated from Cornetto di Matera sourdoughs.

Forty-one strains of lactic acid bacteria (LAB) isolated from Cornetto di Matera sourdoughs were screened for their enzymatic activities, to elucidate their possible roles during the fermentation process. Urease, peptidase, phytase, phosphatase and beta-glucosidase activities were measured spectrophotometrically using synthetic substrates. Proteolytic activities were examined in model doughs, using neutral and acidified sterile doughs as controls. All strains had low urease, glutamyl aminopeptidase and iminopeptidase activities, whereas differences within species were observed for the other enzymatic activities. Leuconostoc mesenteroides and Lactobacillus curvatus strains generally showed high aminopeptidase, X-prolyl dipeptidyl aminopeptidase, beta-glucosidase and phytase activities, while the enzymatic activities of Lactobacillus plantarum, Lactobacillus pentosus and Weissella cibaria varied between strains. In order to classify the strains on the basis of similar enzymatic profiles, a hierarchical cluster analysis was carried out. Several strains of L. plantarum, L. curvatus and Leuc. mesenteroides showed an interesting combination of proteolytic, peptidase, beta-glucosidase and phytase activities, suggesting their possible usefulness as a mixed starter culture in bread-making processes.

6-Phytase↗

Release of tetracycline hydrochloride from electrospun poly(ethylene-co-vinylacetate), poly(lactic acid), and a blend.

Electrospun fiber mats are explored as drug delivery vehicles using tetracycline hydrochloride as a model drug. The mats were made either from poly(lactic acid) (PLA), poly(ethylene-co-vinyl acetate) (PEVA), or from a 50:50 blend of the two. The fibers were electrospun from chloroform solutions containing a small amount of methanol to solubilize the drug. The release of the tetracycline hydrochloride from these new drug delivery systems was followed by UV-VIS spectroscopy. Release profiles from the electrospun mats were compared to a commercially available drug delivery system, Actisite (Alza Corporation, Palo Alto, CA), as well as to cast films of the various formulations.

Anti-Bacterial Agents↗

DNA fingerprinting of thermophilic lactic acid bacteria using repetitive sequence-based polymerase chain reaction.

DNA fingerprints of lactic acid bacteria were generated by polymerase chain reaction using a primer based on the repetitive elements found in the genome of Streptococcus pneumoniae (BOX-PCR). The method made it possible to identify 37 isolates from raw milk. industrial starters and yogurt. Differentiation at species, subspecies and strain level was possible for Lactobacillus delbrueckii subsp. lactis, Lb. delbrueckii subsp bulgaricus and Str. thermophilus. BOX-PCR was also applied to studying the strain composition of a starter culture and the direct detection of strains in commercial fermented milk.

Animals↗

Systemic immunity-enhancing effects in healthy subjects following dietary consumption of the lactic acid bacterium Lactobacillus rhamnosus HN001.

OBJECTIVE: To determine the effects of the probiotic lactic acid bacterium, Lactobacillus rhamnosus HN001, on natural cellular immunity when delivered orally in normal low-fat milk (LFM) or lactose-hydrolyzed low-fat milk (LFM-LH). DESIGN: A three stage, pre-post intervention trial, spanning nine weeks. SETTING: Taipei Medical College Hospital, Taipei, Taiwan. SUBJECTS: Fifty-two healthy middle-aged and elderly volunteers (17 males, 35 females; median age 63.5, range 44-80). INTERVENTIONS: Stage 1 (run-in diet): 25 g/200 mL reconstituted LFM powder, twice daily for 3 weeks. Stage 2 (probiotic intervention): LFM or LFM-LH, supplemented with 10(9) CFUs/g L. rhamnosus HN001 in each case, for 3 weeks. Stage 3 (wash-out): LFM for 3 weeks. MEASURES OF OUTCOME: In vitro phagocytic capacity of peripheral blood polymorphonuclear (PMN) leukocytes; in vitro tumoricidal activity of natural killer (NK) leukocytes. RESULTS: Immunological responses were unaffected by the run-in diet of LFM alone. In contrast, the relative proportion of PMN cells showing phagocytic activity increased by 19% and 15%, respectively, following consumption of HN001 in either LFM or LFM-LH; the relative level of NK cell tumor killing activity increased by 71% and 147%. In most cases these levels declined following cessation, but remained above baseline. CONCLUSIONS: Dietary consumption of L. rhamnosus HN001, in a base of low-fat milk or lactose-hydrolyzed low-fat milk, appears to enhance systemic cellular immune responses and may be useful as a dietary supplement to boost natural immunity.

Adult↗

Toxicity of a new dosage format, cisplatin incorporated in lactic acid oligomer microspheres, in mice.

A new drug delivery system, cisplatin incorporated into lactic acid oligomer microspheres (CDDP-MS), was developed for the treatment of peritoneal carcinomatoses. We studied the acute toxicity and pathological effects of CDDP-MS injected intraperitoneally in mice. The 50% lethal dose was 23.8 mg/kg (21.3-26.7 mg/kg at 95% level of confidence), which was 1.76 times that of the cisplatin aqueous solution of 13.5 mg/kg (11.9-15.3 mg/kg at 95% level of confidence). The duration for the restoration of the body weight loss was prolonged when CDDP-MS at doses close to the 50% lethal dose was administered, as compared with the cisplatin aqueous solution at doses close to its 50% lethal dose. On autopsy there were no macroscopic or microscopic differences between the two dosage forms.

Animals↗

Modulation of allergic immune responses by mucosal application of recombinant lactic acid bacteria producing the major birch pollen allergen Bet v 1.

BACKGROUND: Probiotic lactic acid bacteria (LAB) are able to modulate the host immune system and clinical trials have demonstrated that specific strains have the capacity to reduce allergic symptoms. Therefore, we aimed to evaluate the potential of recombinant LAB producing the major birch pollen allergen Bet v 1 for mucosal vaccination against birch pollen allergy. METHODS: Recombinant Bet v 1-producing Lactobacillus plantarum and Lactococcus lactis strains were constructed. Their immunogenicity was compared with purified Bet v 1 by subcutaneous immunization of mice. Intranasal application of the live recombinant strains was performed to test their immunomodulatory potency in a mouse model of birch pollen allergy. RESULTS: Bet v 1 produced by the LAB was recognized by monoclonal anti-Bet v 1 and IgE antibodies from birch pollen-allergic patients. Systemic immunization with the recombinant strains induced significantly lower IgG1/IgG2a ratios compared with purified Bet v 1. Intranasal pretreatment led to reduced allergen-specific IgE vs enhanced IgG2a levels and reduced interleukin (IL)-5 production of splenocytes in vitro, indicating a shift towards non-allergic T-helper-1 (Th1) responses. Airway inflammation, i.e. eosinophils and IL-5 in lung lavages, was reduced using either Bet v 1-producing or control strains. Allergen-specific secretory IgA responses were enhanced in lungs and intestines after pretreatment with only the Bet v 1-producing strains. CONCLUSIONS: Mucosal vaccination with live recombinant LAB, leading to a shift towards non-allergic immune responses along with enhanced allergen-specific mucosal IgA levels offers a promising approach to prevent systemic and local allergic immune responses.

Administration, Intranasal↗

Probiotic properties of vaginal lactic acid bacteria to prevent metritis in cattle.

AIMS: The isolation of bovine vaginal lactic acid bacteria (LAB) and the screening of their beneficial properties to select those that could be used as probiotics in the prevention of bovine metritis were performed. METHODS AND RESULTS: Out of 76 Lactobacillus sp. and seven Streptococcus sp. strains, a small number showed high- and medium hydrophobicity when the microbial adhesion to hydrocarbons method (MATH) was applied. In the agar plate diffusion test, a large number of strains inhibited vaginal bovine Escherichia coli 99/14 and human E. coli. This inhibition was due to acid. Only a few strains inhibited Actinomyces pyogenes 96/393, a pathogen isolated from bovine metritis. This inhibition remained after neutralization. The taxonomic identification of the selected strains was carried out by an amplified ribosomal DNA restriction analysis (ARDRA). Most of the strains were identified as Lactobacillus fermentum, a few as Lactobacillus gasseri and one as Lactobacillus rhamnosus. CONCLUSIONS: Bovine vaginal lactobacilli strains have differential surface properties. The strains selected are capable of inhibiting specific metritis pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results can be applied for future studies to design a probiotic product to prevent metritis in dairy postpartum cows.

Actinomyces↗

Alteration of the canine small-intestinal lactic acid bacterium microbiota by feeding of potential probiotics.

Five potentially probiotic canine fecal lactic acid bacterium (LAB) strains, Lactobacillus fermentum LAB8, Lactobacillus salivarius LAB9, Weissella confusa LAB10, Lactobacillus rhamnosus LAB11, and Lactobacillus mucosae LAB12, were fed to five permanently fistulated beagles for 7 days. The survival of the strains and their potential effects on the indigenous intestinal LAB microbiota were monitored for 17 days. Denaturing gradient gel electrophoresis (DGGE) demonstrated that the five fed LAB strains survived in the upper gastrointestinal tract and modified the dominant preexisting indigenous jejunal LAB microbiota of the dogs. When the LAB supplementation was ceased, DGGE analysis of jejunal chyme showed that all the fed LAB strains were undetectable after 7 days. However, the diversity of the intestinal indigenous microbiota of the dogs, as characterized from jejunal chyme plated on Lactobacillus selective medium without acetic acid, was reduced and did not return to the original level during the study period. In all but one dog, an indigenous Lactobacillus acidophilus strain emerged as the dominant LAB strain. In conclusion, strains LAB8 to LAB12 have potential as probiotic strains for dogs as they survive in and dominate the jejunal LAB microbiota during feeding and have the ability to modify the intestinal microbiota.

Animals↗

Biopreservation of Brined Shrimp (Pandalus borealis) by Bacteriocins from Lactic Acid Bacteria.

In brined shrimp (ca. 3% NaCl), the effects of three different lactic acid bacteria bacteriocins (crude [6.54 x 10(sup10) U of bacteriocin activity {BU}/g] and purified [8.13 x 10(sup23) BU/g] nisin Z, carnocin UI49 [2.32 x 10(sup4) BU/g], and crude bavaricin A [2.78 BU/g]) on bacterial growth and shelf life were compared with those of a benzoate-sorbate solution (0.1% each [wt/wt]) and a control with no preservatives. The shelf life of shrimp subjected to the control treatment was found to be 10 days. Carnocin UI49 did not extend the shelf life, while crude bavaricin A (a cell-free supernatant of Lactobacillus bavaricus MI 401) resulted in a shelf life of 16 days, as opposed to 31 days with nisin Z for both its crude and purified forms. The benzoate-sorbate solution preserved the brined shrimp for the whole storage period (59 days). In the control, carnocin UI49, and crude bavaricin A treatments, a gram-positive flora dominated towards the end of the storage period while in the nisin Z treatment a gram-negative flora was more pronounced.

Journal Article↗

[Cell growth inhibitory compound from the culture of intestinal lactic acid bacteria].

The influence of the culture supernatants of 1000 strains of intestinal lactic acid bacteria on the growth of HeLa cells was examined. The compound from Enterococcus faecium 3463 showing the strongest cell growth inhibiting effect in these strains was isolated and identified as tyramine. The effect of tyramine was activated by the newborn bovine sera (NBS), but weakly by the fetal bovine sera (FBS). Benzylamine and beta-phenethylamine also showed the NBS-dependent cell growth inhibitory effect against HeLa cells.

Benzylamines↗

A milk-based method for detecting antimicrobial substances produced by lactic acid bacteria.

A new technique for the detection of antimicrobial substances produced by lactic acid bacteria has been developed. In this technique, milk agar plates were supplemented with tetrazolium chloride or tetrazolium blue dyes. Comparisons of milk agar assays with M17 agar plates indicated that, out of 30 bacterial strains, 13 strains produced bacteriocins or inhibitory substances that were detectable on milk agar plates but not on M17 agar plates. Multiple-strain lactococcal cultures are used in milk fermentations. To identify suitable strains to combine for industrial use, component strains must be tested for compatibility. The procedure described allows optimization of compatibility. The assay of putative producer and sensitive indicator strains using milk agar plates (11% nonfat dry milk plus .8% agar and .02% tetrazolium chloride or tetrazolium blue) provides an important tool to prevent allopathic interactions in mixed cultures.

Agar↗

Isolation of cholesterol-lowering lactic acid bacteria from human intestine for probiotic use.

Cholesterol-lowering effect of lactic acid bacteria (LAB: Streptococcus, Lactobacillus and Bifidobacterium) is well-known. Thus, we investigated LAB isolated from human intestine on the cholesterol-lowering effect in vitro. Seven Streptococcus (61.1%), 11 Lactobacillus (71.8%) and 7 Bifidobacterium (27.9%) were isolated as acid (pH 2.5 and 3.0) and bile (0.3% oxgall) tolerant strains. Streptococcus HJS-1, Lactobacillus HJL-37 and Bifidobacterium HJB-4 were finally selected as probiotic strains to use through the bile salt hydrolase (BSH) activity assay by using MRS media added taurodeoxycholic acid (TDCA) and the cholesterol-lowering test by using soluble cholesterol containing MRS broth. These studies suggested that the isolated LAB had an excellent hypocholesterolemic effect.

Amidohydrolases↗

[Biochemical activity of lactic acid bacterial lyophilized concentrates obtained by continous cultivation].

Microbiological and biochemical parameters of lactic acid bacterial lyophilized concentrates obtained by continous cultivation were investigated during their storage at 3 to 5 degrees C. Under these conditions lyophilized bacterial concentrates retained high activity for three months and after six months their cell survival and biochemical activity decreased by 60--65% on the average.

Bacteria↗

Resorbable poly-L-lactic acid mini-staples for the fixation of Akin osteotomies.

The authors present a new fixation system constituted by reabsorbable mini-staples in poly-L-lactic acid, the use of which is proposed for Akin osteotomies. An initial cohort of 25 cases (23 patients), with a mean follow-up of 16 months (minimum 6 months, maximum 30 months) is presented. In 24 cases union of the osteotomy was found within 30 days of the surgical treatment; however, in one case it took longer (12 weeks). Neither pseudoarthrosis, malunion, nor breakage of the mini-staples was found. No adverse tissue reactions were observed. In all cases good deformity correction was achieved, with patient satisfaction reported in about 96% of the cases. In this type of surgery and in selected cases (without osteoporosis and/or severe arthritis of the first metatarsophalangeal joint), this fixation device is an interesting alternative to the traditional nonabsorbable types.

Adult↗

Spatial and temporal distribution of non-starter lactic acid bacteria in Cheddar cheese.

AIMS: The aim of this work was to investigate the spatial and temporal distribution of species and strains of non-starter lactic acid bacteria (NSLAB) within Cheddar cheese. METHODS AND RESULTS: Randomly amplified polymorphic DNA was used to identify and track the principle species and strain groups of NSLAB present. The same strains dominated each location examined within a cheese at any particular time point. Temporal change in species and strains of NSLAB during ripening was observed. A mixture of Lactobacillus paracasei, Lact. plantarum, Lact. rhamnosus and unidentified strains was found up to 6 weeks of maturation, thereafter only Lact. paracasei strains were isolated. CONCLUSION: Little variation in the spatial distribution of NSLAB strains occurs within Cheddar cheese; however, temporal changes in the species and strains were observed during ripening. SIGNIFICANCE AND IMPACT OF THE STUDY: The complex changes in the composition of the NSLAB community of Cheddar cheese may be the source of the variation in flavour that is seen in commercial practice.

Cheese↗

Treatment of onychomycosis with a propylene glycol-urea-lactic acid solution.

Twenty three patients with culture positive onychomycosis were treated topically twice daily for 2-6 month with a solution containing 10 g urea, 15 g lactic acid, 4 g NaOH, 21 g water, and 50 g propylene glycol. Trichophyton rubrum was cultured in 17 patients and Candida albicans in 6 patients. The solution was effective in 21 of the 23 patients with cure in 2 patients, marked improvement in 11 patients and improvement in 8 of the patients. In the patients with marked improvement some nails were often completely cured. The good effect of this solution in the treatment of onychomycosis is in correlation with a good in vitro activity with MICs of 5% against Tr. rubrum and 10% against C. albicans and a high penetration into nails in vitro. The patients found the solution cosmetically attractive and no side effects were noticed by the patients. Even if the treatment period was short the good effect in the majority of the patients indicates that this solution is effective in topical treatment of onychomycosis.

Administration, Topical↗