[Determination of smallest amounts of lactic acid].
Explore the source record for details and available documents.
Humans↗
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.
A study of cements formed by aqueous lactic acid and aluminosilicate glass.
A study is reported of the formation of cements from aqueous lactic acid and aluminosilicate glass of the type used in dental glass-ionomer cements. These cements were found to set quickly, and were shown by infrared spectroscopy to have undergone a neutralization reaction to yield mainly calcium lactate. They were very soluble in water at 1 h, but became progressively less so over time; when matured for 6 h before being placed in water, they had become almost insoluble. No spectroscopic differences could be detected between the cements at 1 h or 6 h, indicating that insolubilization arises from a reaction that does not alter the part of the infrared spectrum examined. This suggested that a wholly inorganic reaction between the ion-depleted glass fragments is responsible for the formation of the insoluble structure. After 24 h, the cements were found to have compressive strengths in the range 9-35 MPa, the actual value varying with concentration of lactic acid used to form the cement, and there was no statistically significant increase in strength for the strongest of these after one month.
Journal Article↗
The biodiversity of lactic acid bacteria in Greek traditional wheat sourdoughs is reflected in both composition and metabolite formation.
Lactic acid bacteria (LAB) were isolated from Greek traditional wheat sourdoughs manufactured without the addition of baker's yeast. Application of sodium dodecyl sulfate-polyacrylamide gel electrophoresis of total cell protein, randomly amplified polymorphic DNA-PCR, DNA-DNA hybridization, and 16S ribosomal DNA sequence analysis, in combination with physiological traits such as fructose fermentation and mannitol production, allowed us to classify the isolated bacteria into the species Lactobacillus sanfranciscensis, Lactobacillus brevis, Lactobacillus paralimentarius, and Weissella cibaria. This consortium seems to be unique for the Greek traditional wheat sourdoughs studied. Strains of the species W. cibaria have not been isolated from sourdoughs previously. No Lactobacillus pontis or Lactobacillus panis strains were found. An L. brevis-like isolate (ACA-DC 3411 t1) could not be identified properly and might be a new sourdough LAB species. In addition, fermentation capabilities associated with the LAB detected have been studied. During laboratory fermentations, all heterofermentative sourdough LAB strains produced lactic acid, acetic acid, and ethanol. Mannitol was produced from fructose that served as an additional electron acceptor. In addition to glucose, almost all of the LAB isolates fermented maltose, while fructose as the sole carbohydrate source was fermented by all sourdough LAB tested except L. sanfranciscensis. Two of the L. paralimentarius isolates tested did not ferment maltose; all strains were homofermentative. In the presence of both maltose and fructose in the medium, induction of hexokinase activity occurred in all sourdough LAB species mentioned above, explaining why no glucose accumulation was found extracellularly. No maltose phosphorylase activity was found either. These data produced a variable fermentation coefficient and a unique sourdough metabolite composition.
Bacterial Proteins↗
Antimicrobial activity of sulfur dioxide to certain lactic acid bacteria isolated from wines.
This study was conducted to investigate the relationship between pH and the toxicity of sulfur dioxide against homo- and hetero-lactic acid bacteria isolated from American acidic wines. Malolactic fermentation was found to be growth-associated in homo- and hetero-lactic strains. The pH of CBB broth had an insignificant effect on the specific death rate of these strains; the concentration of molecular sulfur dioxide had a great effect on the specific death rate and malate degradation. Laboratory or freshly isolated strains were exposed to various concentrations of free sulfur dioxide at pH 3.8 and 3.4. At pH 3.4, sulfur dioxide was more effective against lactic acid bacteria than at pH 3.8 since more was present as molecular sulfur dioxide and causing an increase in the specific death rate. Pediococcus strain BB was more resistant to sulfur dioxide than those hetero-lactic fermentation strains such as Leuconostoc oenos PSU-1 and ML-34. The effect of sulfur dioxide concentration on the viability of L. oenes ML-34, PSU-1, and Pediococcus strain BB appeared to be biphasic. No or little L-malic acid was degraded when the homo- and hetero-fermentative strains were killed by sulfur dioxide.
Hydrogen-Ion Concentration↗
Effect of (poly)-L-lactic acid on the proliferation and differentiation of primary bone cells in vitro.
A previous study has shown bone formation around poly-L-lactic acid (PLLA) wire in vivo. However, it is still unknown how bone cells are stimulated to form bone around PLLA wire. The effect of PLLA on primary bone cells in vitro is the subject of this study. Osteoprogenitor and osteoblastic cells derived from neonatal mouse calvaria were cultured after addition of PLLA wire or L-lactide to the culture medium. Alkaline phosphatase (AP) activity, as a parameter of bone cell differentiation, and DNA content, to assess cell growth were measured. In osteoblast-enriched cell cultures PLLA wire did not affect DNA content, but AP activity was increased by 28%. In osteoprogenitor-enriched cell cultures PLLA wire decreased DNA content by 10%, but AP activity of the cells was not affected. L-Lactide enhanced the DNA content of osteoblastic cell cultures at 0.1 mM by 19%, but not at higher concentrations, and did not affect cell differentiation. In osteoprogenitor cell cultures, L-lactide had no effect at all. These results indicate that the proliferation and differentiation of bone cells in vitro can be modulated by PLLA, dependent on their stage of differentiation. L-Lactide at concentrations up to 10 mM did not adversely affect cell growth or differentiation, while PLLA wire upregulated the expression of the osteoblastic phenotype. These data support the observation of newly formed bone around poly-lactic acid wire in vivo in other the studies.
Alkaline Phosphatase↗
[Changes in blood levels of glucose and lactic acid in pregnant sows and fetuses and in sows and piglets 10 days after parturition].
In three series of experiments the variations of lactic acid and glucose concentrations were investigated in pregnant sows, crossbreds of the Large White and Landrace breeds, and in their foetuses on the 104th and 113th day of pregnancy, then in farrowing sows of the same breed and their piglets at delivery (birth) and till the 10th day after birth. In nonpregnant sows the value of lactacidaemia is 1.60 +/- 0.08 mmol per 1. In the first twenty days of pregnancy it increases to 2.50 +/- 0.95 mmol per 1 (p less than 0.05). In the following days of pregnancy until the 81st to 100th day the value ranges from 1.5 to 1.7 mmol per 1. In the last twenty days of pregnancy it increases slightly to 2.10 +/- 0.25 mmol per 1. On the 104th and 113th day the values of lactacidaemia in foetuses in vena and arteria umbilicalis make 7.40 +/- 0.41 and 6.80 +/- 0.37, or 8.50 +/- 0.43 and 8.16 +/- 0.21 mmol per 1, respectively. Glucosaemia values are decreasing in pregnant sows in the first forty days, in the following period of pregnancy they are increasing and on the 101st to 120th day of pregnancy they make 5.39 +/- 0.26 mmol per 1. The foetus to dam ratio lactic acid concentrations is 2.3 and 2.1, respectively, on the 104th and 113th days. Lactacidaemia is highest in farrowing sows (3.15 +/- 0.19 mmol per 1), then there is a statistically significant decrease in the value of this characteristic, and on the day after delivery it makes 2.38 +/- 0.66 mmol per 1.(ABSTRACT TRUNCATED AT 250 WORDS)
Age Factors↗
Production of probiotic cabbage juice by lactic acid bacteria.
Research was undertaken to determine the suitability of cabbage as a raw material for production of probiotic cabbage juice by lactic acid bacteria (Lactobacillus plantarum C3, Lactobacillus casei A4, and Lactobacillus delbrueckii D7). Cabbage juice was inoculated with a 24-h-old lactic culture and incubated at 30 degrees C. Changes in pH, acidity, sugar content, and viable cell counts during fermentation under controlled conditions were monitored. L. casei, L. delbrueckii, and L. plantarum grew well on cabbage juice and reached nearly 10x10(8) CFU/mL after 48 h of fermentation at 30 degrees C. L. casei, however, produced a smaller amount of titratable acidity expressed as lactic acid than L. delbrueckii or L. plantarum. After 4 weeks of cold storage at 4 degrees C, the viable cell counts of L. plantarum and L. delbrueckii were still 4.1x10(7) and 4.5x10(5) mL(-1), respectively. L. casei did not survive the low pH and high acidity conditions in fermented cabbage juice and lost cell viability completely after 2 weeks of cold storage at 4 degrees C. Fermented cabbage juice could serve as a healthy beverage for vegetarians and lactose-allergic consumers.
Bacteria↗
Fermentation of sugar cane bagasse hemicellulose hydrolysate to L(+)-lactic acid by a thermotolerant acidophilic Bacillus sp.
Sugar cane bagasse hemicellulose, hydrolyzed by dilute H2SO4, supplemented with mineral salts and 0.5% corn steep liquor, was fermented to L(+)-lactic acid using a newly isolated strain of Bacillus sp. In batch fermentations at 50 degrees C and pH 5, over 5.5% (w/v) L(+)-lactic acid was produced (89% theoretical yield; 0.9 g lactate per g sugar) with an optical purity of 99.5%.
Bacillus↗
Description of Paralactobacillus selangorensis gen. nov., sp. nov., a new lactic acid bacterium isolated from chili bo, a Malaysian food ingredient.
Paralactobacillus selangorensis gen. nov., sp. nov. is described. This organism, isolated from a Malaysian food ingredient called chili bo, is an obligatory homofermentative, rod-shaped lactic acid bacterium. The G+C content is 46.1-46.2+/-0.3 mol%. Earlier 16S rRNA studies showed that this organism constitutes a new taxon distantly related to the Lactobacillus casei-Pediococcus group. A phenotypic description that distinguishes Paralactobacillus selangorensis from other genera of lactic acid bacteria is presented. The type strain of Paralactobacillus selangorensis is LMG 17710T.
Acetic Acid↗
D(--)-lactic acid and d(--)-lactate dehydrohgenase in octopus spermatozoa.
The spermatozoa of Octopus dofleini martini produce anaerobically D(-)-lactic acid and possess a very active D(-)-lactate dehydrogenase. In this respect, while resembling certain microorganisms, they differ strikingly from mammalian spermatozoa which produce L(+)-lactic acid and contain L(+)-lactate dehydrogenase.
Anaerobiosis↗
Comparative efficacy of 12% ammonium lactate lotion and 5% lactic acid lotion in the treatment of moderate to severe xerosis.
This double-blind study was designed to evaluate treatment results and time effects of 12% ammonium lactate and 5% lactic acid lotion for moderate to severe xerosis. Results showed 12% ammonium lactate lotion was significantly more effective than 5% lactic acid lotion in reducing the severity of xerosis in both the 3-week, twice-a-day treatment period and the following 3-week, no-treatment (regression) period.
Adult↗
Effect of lactic acid bacteria on diarrheal diseases.
Microbial balance is an important factor in the maintenance of intestinal homeostasis, and yogurt or fermented milk supplementation has been proposed to control diarrheal diseases. A number of studies using animal models and clinical studies in humans have confirmed the beneficial effect of such fermented products in case of lactose intolerance, viral diarrhea or antibiotics-associated diarrhea. The mechanisms by which lactic acid bacteria exert their effects are multiple. Bacterial lactase improves the absorption of lactose, but fermented products slow down the intestinal transit facilitating the action of residual intestinal lactase. The transient passage of lactic acid bacteria in the digestive tract may represent a microbial barrier against the development of pathogenic bacteria, probably due to the release of compounds contributing to the maintenance of colonization resistance to pathogens. The beneficial effects are mainly described in the presence of live bacteria, but inactivated bacteria may also present preventive or curative capacities in diarrheal diseases. Moreover, lactic acid bacteria has been described as reinforcing the non-specific immune defence but also specific immunity, particularly the secretory immune system mediated by secretory IgA or IgM in response to particulate infectious antigens and perhaps to soluble food antigens. Other possible mechanisms include the trophic effect on the intestinal layer, and a down-regulatory activity in cow's milk allergy as well as anti-inflammatory effects have also been suggested.
Diarrhea↗
Antimould activity of sourdough lactic acid bacteria: identification of a mixture of organic acids produced by Lactobacillus sanfrancisco CB1.
Sourdough lactic acid bacteria, cultivated in wheat flour hydrolysate, produced antimould compounds. The antimould activity varied greatly among the strains and was mainly detected within obligately heterofermentative Lactobacillus spp. Among these, Lb. sanfrancisco CB1 had the largest spectrum. It inhibited moulds related to bread spoilage such as Fusarium, Penicillium, Aspergillus and Monilia. A mixture of acetic, caproic, formic, propionic, butyric and n-valeric acids, acting in a synergistic way, was responsible for the antimould activity. Caproic acid played a key role in inhibiting mould growth.
Antifungal Agents↗
Restriction fragment length polymorphism analysis of 16S rRNA genes in lactic acid bacteria isolated from red wine.
Various lactic acid bacteria isolated from wine and alcoholic drinks attempted to identified by restriction fragment length polymorphism (RFLP). Oenococcus oeni strains exhibited unique RFLP patterns by HaeIII-digestion of 12 reference strains. We performed RFLP analysis using the AccII or HaeIII enzyme for 44 strains isolated from red wine and the results indicated profiles identical to O. oeni type strain. O. oeni does not exhibit interspecific diversity. Thus, the use of RFLP analysis of 16S rDNA is useful in the identification of O. oeni strains isolated from wines.
Journal Article↗
Exploiting expolysaccharides from lactic acid bacteria.
Microbial exopolysaccharides (EPSs) synthesized by lactic acid bacteria (LAB) play a major role in the manufacturing of fermented dairy products. EPS production is characterized by a large variety in terms of quantity, chemical composition, molecular size, charge, type of sidechains and rigidity of the molecules. Monosaccharide unit's composition, linkages, charge and size determine the EPS' intrinsic properties and their interactions with other milk constituents. EPSs contribute to texture, mouthfeel, taste perception and stability of the final product. Furthermore, it was reported that EPS from food grade organisms, particularly LAB, have potential as food additives and as functional food ingredients with both health and economic benefits. A better understanding of structure-function relationships of EPS in a dairy food matrix and of EPS biosynthesis remain two major challenges for further applications of EPS and the engineering of functional polysaccharides.
Animals↗
Lactic acid bacteria isolated from canine faeces.
AIMS: Lactic acid bacteria (LAB) were isolated and sequenced from the faeces of healthy dogs. Five of these strains were selected and further characterized to clarify the potential of these strains as probiotics for canine. METHODS AND RESULTS: LAB were found in 67% (14/21) of the canine faeces samples when plated on Lactobacilli Selective Media without acetic acid. Out of 13 species identified with partial 16S rRNA gene sequencing, Lactobacillus fermentum LAB8, L. mucosae LAB12, L. rhamnosus LAB11, L. salivarius LAB9 and Weissella confusa LAB10 were selected as candidate probiotic strains based on their frequency, quantity in faeces, growth density, acid tolerance and antimicrobial activity. The minimal inhibitory concentration values of these isolates were determined for 14 antibiotics. L. salivarius LAB9, W. confusa LAB10 and L. mucosae LAB12 were viable in pH 2 for 4 h (mLBS), indicating tolerance to acidity and thus the potential to survive in gastrointestinal tract of the canine. The LAB8-LAB12 strains showed antimicrobial activity against Micrococcus luteus A1 NCIMB86166. CONCLUSIONS: Thirteen different LAB species were found from the faecal microbiota of the healthy canines. Five acid tolerant and antimicrobially active LAB strains with the capacity to grow to high densities both aerobically and anaerobically were chosen to serve as candidate probiotics. SIGNIFICANCE AND IMPACT OF THE STUDY: The selected LAB strains are among the first host-specific LAB with antimicrobial activity isolated from canines that could serve as potential probiotics for canine use.
Animals↗
Antibiotic resistances of starter and probiotic strains of lactic acid bacteria.
The antibiotic resistances of 45 lactic acid bacteria strains belonging to the genera Lactobacillus, Streptococcus, Lactococcus, Pediococcus, and Leuconostoc were investigated. The objective was to determine antibiotic resistances and to verify these at the genetic level, as is currently suggested by the European "qualified presumption of safety" safety evaluation system for industrial starter strains. In addition, we sought to pinpoint possible problems in resistance determinations. Primers were used to PCR amplify genes involved in beta-lactam antibiotic, chloramphenicol, tetracycline, and erythromycin resistance. The presence of ribosomal protection protein genes and the ermB gene was also determined by using a gene probe. Generally, the incidences of erythromycin, chloramphenicol, tetracycline, or beta-lactam resistances in this study were low (<7%). In contrast, aminoglycoside (gentamicin and streptomycin) and ciprofloxacin resistances were higher than 70%, indicating that these may constitute intrinsic resistances. The genetic basis for ciprofloxacin resistance could not be verified, since no mutations typical of quinolone resistances were detected in the quinolone determining regions of the parC and gyrA genes. Some starter strains showed low-level ampicillin, penicillin, chloramphenicol, and tetracycline resistances, but no known resistance genes could be detected. Although some strains possessed the cat gene, none of these were phenotypically resistant to chloramphenicol. Using reverse transcription-PCR, these cat genes were shown to be silent under both inducing and noninducing conditions. Only Lactobacillus salivarius BFE 7441 possessed an ermB gene, which was encoded on the chromosome and which could not be transferred in filter-mating experiments. This study clearly demonstrates problems encountered with resistance testing, in that the breakpoint values are often inadequately identified, resistance genes may be present but silent, and the genetic basis and associated resistance mechanisms toward some antibiotics are still unknown.
Amino Acid Sequence↗
Microbial quality and direct PCR identification of lactic acid bacteria and nonpathogenic Staphylococci from artisanal low-acid sausages.
Detection of six species of lactic acid bacteria and six species of gram-positive catalase-positive cocci from low-acid fermented sausages (fuets and chorizos) was assessed by species-specific PCR. Without enrichment, Lactobacillus sakei and Lactobacillus curvatus were detected in 11.8% of the samples, and Lactobacillus plantarum and Staphylococcus xylosus were detected in 17.6%. Enriched samples allowed the detection of L. sakei and S. xylosus in all of the samples (100%) and of Enterococcus faecium in 11.8% of the sausages. The percentages of L. curvatus, L. plantarum, Staphylococcus carnosus, and Staphylococcus epidermidis varied depending on the sausage type. L. curvatus was detected in 80% of fuets and in 57% of chorizos. L. plantarum was found in 50% of fuets and 100% of chorizos. S. epidermidis was detected in only 11.8% of fuets, and S. carnosus was detected in only 5.9% of chorizos. Lactococcus lactis, Staphylococcus warneri, and Staphylococcus simulans were not detected in any sausage type. From a microbiological point of view, 70.6% of the samples could be considered of high quality, as they had low counts of Enterobacteriaceae and did not contain any of the food-borne pathogens assayed.
Base Sequence↗