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PubMedDate not supplied

Changes of glucose utilization by erythrocytes, lactic acid concentration in the serum and blood cells, and haematocrit value during one hour rest after maximal effort in individuals differing in physical efficiency.

Glucose utilization by the erythrocytes, lactic acid concentration in the blood and erythrocytes, and haematocrit value were determined before exercise and during one hour rest following maximal exercise in 97 individuals of either sex differing in physical efficiency. In the investigations reported by the author individuals with strikingly high physical fitness performed maximal work one-third greater than that performed by individuals with medium fitness. The serum concentration of lactic acid was in all individuals above the resting value still after 60 minutes of rest. On the other hand, this concentration returned to the normal level in the erythrocytes but only in individuals with strikingly high efficiency. Glucose utilization by the erythrocytes during the restitution period was highest immediately after the exercise in all studied individuals and showed a tendency for more rapid return to resting values again in individuals with highest efficiency. The investigation of very efficient individuals repeated twice demonstrated greater utilization of glucose by the erythrocytes at the time of greater maximal exercise. This was associated with greater lactic acid concentration in the serum and erythrocytes throughout the whole one-hour rest period. The observed facts suggest an active participation of erythrocytes in the process of adaptation of the organism to exercise.

Adolescent↗
PubMed1990

Sustained release of insulin by double-layered implant using poly(D,L-lactic acid).

This report describes the advantage of double-layered implants using low molecular weight poly(DL-lactic acid) in the sustained release of insulin. The double-layered implant consisted of a polymer matrix containing insulin and a polylactic acid layer which was coated partially on one of the surfaces of the insulin:polymer matrix. The double-layered implants were compared with single-matrix implants from the standpoint of the in vitro dissolution test and in vivo performance. In vitro release rates were controlled by changing the amount of poly(DL-lactic acid) used in the polymer layer. In an in vivo test using diabetic animals, the double-layered implants provided a sustained release of insulin for 19 d, as judged by the changes in blood glucose levels and serum insulin levels after the subcutaneous implantation.

Animals↗
PubMed2003

Food additive lactic acid production by immobilized cells of Lactobacillus brevis on delignified cellulosic material.

Improvements in yield and productivity in lactic acid fermentation by Lactobaccilus brevis cells immobilized on delignified cellulosic (DC) material are reported. The system proved to be more efficient in comparison with the work reported by other workers. Yields of 80 and 100% conversion using glucose were obtained at 30 degrees C in 1 day of fermentation time. Lactic acid fermentation using whey as substrate was obtained at 30 degrees C in 1-1.5 days, resulting in 70% yield, whereas the remaining lactose in whey was converted to alcohol byproduct, leading to a 90% lactose exploitation and 100% conversion. Cell immobilization of L. brevis on DC material was proved by its reuses in repeated batch fermentations and through electron microscopy. A series of 10 repeated batch fermentations without any loss in cell activity showed a tendency for high operational stability. The presence of DC material resulted in a drastic drop of the fermentation time from 48 to 13 h.

Cellulose↗
PubMed2005

Kinetic modelling of Lactobacillus casei ssp. rhamnosus growth and lactic acid production in batch cultures under various medium conditions.

Enrichment of medium with yeast extract and tryptone increased growth and lactic acid production in batch cultures of Lactobacillus casei ssp. rhamnosus. A reliable kinetic model that explicitly expresses the strong relationship between microbial growth, lactic acid production and medium enrichment is provided and validated using experimental data obtained with six different medium compositions.

Cell Culture Techniques↗
PubMed2003

Synergistic attraction of Aedes aegypti (L.) to binary blends of L-lactic acid and acetone, dichloromethane, or dimethyl disulfide.

Kairomones produced by humans provide female anthropophilic mosquitoes with vital cues used in host-seeking for a blood meal. These chemicals are emanated primarily by the skin and provide the mosquitoes a means to orient themselves to humans at a relatively close range. Chemical studies of these emanations have provided new ideas for the formulation of attractant blends. We report mosquito attraction responses for three binary blends and their separate components. The blends are comprised of L-lactic acid plus either acetone, dichloromethane, or dimethyl disulfide. At the emission rates used in our bioassays, these blends synergistically attract laboratory-reared female Aedes aegypti. Carbon dioxide is not a necessary component to yield high levels of attraction with these blends. It is postulated that at least one of these synergistic blends (L-lactic acid and acetone) produces mosquito attraction behavior similar to L-lactic acid and CO2.

Acetone↗
PubMed2002

Selection of bacteriocin producer strains of lactic acid bacteria from a dairy environment.

Two strains showing bacteriocin production were selected from a total of 206 lactic acid bacteria isolated from samples of milk, milk serum, whey and homemade cheeses in Southern Cordoba, Argentina. This property was detected by means of well diffusion assays. The strains were identified as Enterococcus hirae and Enterococcus durans. The protein nature of those substances was proved by showing their sensitivity to type IV and XXV proteases, papaine, trypsin, pepsin and K proteinase. The bacteriocins inhibited the growth of Listeria monocytogenes, Bacillus cereus, Clostridium perfringes and two strains of Staphylococcus aureus, an A-enterotoxin and a B-enterotoxin producers. All of these bacteria are common pathogens usually associated with food borne diseases (ETA). These lactic acid bacteria or their bacteriocins could be suitable candidates for food preservation and specially useful in the our regional dairy industry.

Animals↗
PubMed2005

A media design program for lactic acid production coupled with extraction by electrodialysis.

The aim of this study was to investigate industrial media for lactic acid fermentation to reduce the cost of nitrogen sources. Corn steep liquor (CSL) was successfully used at 5% (v/v) in batch fermentations. Use of soluble CSL improved the productivity approximately 20% with an advantage of clearer fermentation broth. Yeast extract (YE)-complemented CSL media further increased the productivity. It was found that 3.1 g L(-1) yeast extract and 5% CSL could be an effective substitute for 15 g L(-1) yeast extract in 10% glucose medium. Spent brewery yeast was also used as a sole nitrogen source equivalent to 5% CSL. Lactic acid was recovered by electrodialysis from the cell free broth. Depleted cell free broth supplemented with 5 g L(-1) of yeast extract performed reasonably in batch cultures. Reuse of the fermentation broth may reduce the cost of raw materials as well as minimize the fermentation wastes.

Bioreactors↗
PubMed1996

Biosynthesis of bacteriocins in lactic acid bacteria.

A large number of new bacteriocins in lactic acid bacteria (LAB) has been characterized in recent years. Most of the new bacteriocins belong to the class II bacteriocins which are small (30-100 amino acids) heat- stable and commonly not post-translationally modified. While most bacteriocin producers synthesize only one bacteriocin, it has been shown that several LAB produce multiple bacteriocins (2-3 bacteriocins). Based on common features, some of the class II bacteriocins can be divided into separate groups such as the pediocin-like and strong anti-listeria bacteriocins, the two-peptide bacteriocins, and bacteriocins with a sec-dependent signal sequence. With the exception of the very few bacteriocins containing a sec-dependent signal sequence, class II bacteriocins are synthesized in a preform containing an N-terminal double-glycine leader. The double-glycine leader-containing bacteriocins are processed concomitant with externalization by a dedicated ABC-transporter which has been shown to possess an N-terminal proteolytic domain. The production of some class II bacteriocins (plantaricins of Lactobacillus plantarum C11 and sakacin P of Lactobacillus sake) have been shown to be transcriptionally regulated through a signal transduction system which consists of three components: an induction factor (IF), histidine protein kinase (HK) and a response regulator (RR). An identical regulatory system is probably regulating the transcription of the sakacin A and carnobacteriocin B2 operons. The regulation of bacteriocin production is unique, since the IF is a bacteriocin-like peptide with a double-glycine leader processed and externalized most probably by the dedicated ABC-transporter associated with the bacteriocin. However, IF is not constituting the bacteriocin activity of the bacterium, IF is only activating the transcription of the regulated class II bacteriocin gene(s). The present review discusses recent findings concerning biosynthesis, genetics, and regulation of class II bacteriocins.

ATP-Binding Cassette Transporters↗
PubMed1993

Behaviour of Listeria monocytogenes during the maturation of naturally and artificially contaminated salami: effect of lactic-acid bacteria starter cultures.

The antimicrobial activity of a bacteriocin-producing Lactobacillus plantarum MCS strain against Listeria monocytogenes in naturally and artificially contaminated salami was evaluated in comparison with that of other non bacteriocin-producing lactic-acid bacteria (i.e., L. plantarum MCS1 mutant strain and two commercial starter cultures). In salami not inoculated with lactic-acid bacteria, moderate L. monocytogenes growth was observed after 7-14 days. The addition of the starter cultures prevented growth, but not always the survival of Listeria. During the maturation of artificially-contaminated salami, Listeria counts tended to decrease, but no significant differences were observed between samples inoculated with L. plantarum MCS or with the MCS1 bacteriocin-negative mutant strain. However, at the end of the maturation period, in naturally-contaminated salami, differences in the survival of Listeria (recovered by enrichment) were observed in the batches inoculated with the different lactic-acid bacteria: Listeria appeared to be absent only in salami inoculated with the L. plantarum MCS strain.

Bacteriocins↗
PubMed2006

Lactic acid production from sugar-cane juice by a newly isolated Lactobacillus sp.

A newly isolated sucrose-tolerant, lactic acid bacterium, Lactobacillus sp. strain FCP2, was grown on sugar-cane juice (125 g sucrose l(-1), 8 g glucose l(-1) and 6 g fructose l(-1)) for 5 days and produced 104 g lactic acid l(-1) with 90% yield. A higher yield (96%) and productivity (2.8 g l(-1 )h(-1)) were obtained when strain FCP2 was cultured on 3% w/v (25 g sucrose l(-1), 2 g glucose l(-1) and 1 g fructose l(-1)) sugar-cane juice for 10 h. Various cheap nitrogen sources such as silk worm larvae, beer yeast autolysate and shrimp wastes were also used as a substitute to yeast extract.

Fermentation↗
PubMed1999

Origin of extracellular dopamine increase induced by lactic acid striatal perfusion monitored by microdialysis in the awake rat.

In previous studies we showed that a striatal lactic acid perfusion-induced lactacidosis produces a diphasic increase in extracellular dopamine (DA). In the present study, different pharmacological reagents were used to determine the origin of accumulated DA. Our data show that both DA accumulations were totally suppressed by tetrodotoxin and nicardipine, indicating a relationship with membrane depolarization and a Ca(2+)-dependent effect. The first DA peak was largely reduced by a specific inhibitor of DA uptake such as GBR-12935, and the second was totally suppressed by tyramine and reserpine and lowered and delayed by GBR-12935. These results compared to data in the literature suggest that the first increase in extracellular DA resulted mainly from a release of cytosolic DA by reversal of the DA transporter, while the second was mainly due to a release of vesicular DA by exocytosis. These data indicate that lactic acid perfusion helps clarify the mechanisms involved in this process and could be useful for the study of new treatments against the hyperactive dopaminergic reaction occuring during ischemia.

Adrenergic Uptake Inhibitors↗
PubMed1990

[Effect of biguanides on the indicators of thrombelastography and the level of lactic acid in diabetes mellitus].

The authors analyze the results of examinations of 232 patients with diabetes mellitus; 48 of these suffering from type I diabetes and 64 from type II diabetes were treated with biguanides. Thromboelastograms were recorded in the presence of hyperglycemia and repeatedly during stable compensation of diabetes, and their values were analyzed with due consideration for therapy administered. Since biguanides are known to induce lactate acidosis, blood serum lactic acid levels were measured when the patients were hospitalized, in the presence of hyperglycemia, and then after a standard exercise test (to detect latent acidosis). When stable compensation of diabetes mellitus was achieved, the examination scheme described before was repeated, i. e. lactic acid measurements before and after exercise test, with due consideration for the therapy administered. Biguanides were found to be conducive to normalization of thrombelastogram values, not elevating the blood serum content of lactic acid even after exercise test.

Adolescent↗
PubMed2006

Biocompatibility of poly-DL-lactic acid (PDLLA) for lung tissue engineering.

This study explores the possibility of growing lung cells on poly-DL-lactic acid (PDLLA) scaffolds, with a view to in future engineer pulmonary tissue for human implantation. As a first step in this process, the ability of PDLLA to maintain the growth of lung epithelium is tested using a robust cell line. Poly-DL-lactic acid has been investigated in two forms, as planar discs and as 3-D foams, and it has been demonstrated that PDLLA is not only nontoxic to pneumocytes but it also actively supports their growth. The initial findings suggest that the material is an appropriate matrix for engineering of distal lung tissue.

Animals↗
PubMed1995

The effects of potassium sorbate and lactic acid on the shelf-life of vacuum-packed chicken meats.

In this research, the effects of 5% potassium sorbate (PS) and 3% lactic acid (LA) applications on total mesophylic aerobic bacteria, total psychrotrophic aerobic bacteria, lactic acid bacteria, staphylococci and coliform bacteria, pH values, thiobarbituric acid (TBA) numbers, and sensorial properties of vacuum-packed chicken leg and breast meats were investigated during storage at 4 +/- 1 C. In addition, residual sorbate was examined. A decrease in bacterial counts of chicken leg and breast meats was observed in the periods following the treatments of PS and LA; however, towards the end of the storage period, the effectiveness of PS was greater than that of LA. Although no effect was observed on pH values of samples treated with PS, LA caused a decrease in pH values in chicken meats. Both PS and LA treatments resulted in high TBA numbers. Although the shelf-life periods of samples treated with PS and LA were about 30 d, vacuum-packed controls and unsealed controls (both of which were untreated) lost their edibility on the 18th and the 6th d, respectively. Sensory analysis panel members could not distinguish between PS samples and control samples. However, samples containing LA had lower scores than others. Both PS and LA treatments were considered to be acceptable. Quantities of sorbic acid found in the samples treated with PS were below the Acceptable Daily Intake established by the Food and Agriculture Organization/World Health Organization.

Animals↗
PubMed2005

[Influence of microbiological quality of lactic acid cheese on water phase in conditions of hermetic packing].

Aim of research was to assess the influence of lactic acid cheese micro-flora on water phase fluctuation between surface of products and the packaging. Results of research showed that changes of water content could be expressed with the help of polynomial cubic equation. From linear correlation equations describing level of micro-flora in lactic acid cheese and water content it resulted micro-organisms had a significant influence on the water phase fluctuation. Values of determined coefficients of determination suggested that yeast, enterococci and staphylococci had a significant influence on water fluctuation between product and the packaging.

Cheese↗
PubMed2003

Repair of radius defect with bone-morphogenetic-protein loaded hydroxyapatite/collagen-poly(L-lactic acid) composite.

OBJECTIVE: To explore the method to repair bone defect with bone-morphogenetic-protein loaded hydroxyapatite/collagen-poly(L-lactic acid) composite. METHODS: 18 adult beagle dogs were randomly divided into 3 groups. In Group A, bone-morphogenetic-protein (BMP) loaded hydroxyapatite/collagen-poly(L-lactic acid) (HAC-PLA) scaffold was implanted in a 2 cm diaphyseal defect in the radius. In Group B, unloaded pure HAC-PLA scaffold was implanted in the defects. No material was implanted in Group C (control group). The dogs were sacrificed 6 months postoperatively. Features of biocompatibility, biodegradability and osteoinduction were evaluated with histological, radiological examinations and bone mineral density (BMD) measurements. RESULTS: In Group A, the radius defect healed after the treatment with BMP loaded HAC-PLA. BMD at the site of the defect was higher than that of the contralateral radius. Fibrous union developed in the animals of the control group. CONCLUSIONS: BMP not only promotes osteogenesis but also accelerates degradation of the biomaterials. Optimized design parameters of a three-dimensional porous biomaterial would give full scope to the role of BMP as an osteoinductive growth factor.

Animals↗
PubMed2004

Oxalate degradation by intestinal lactic acid bacteria in dogs and cats.

This study evaluated the ability of the lactic acid bacteria (LAB) component of canine and feline feces to degrade oxalate in vitro. Oxalate degradation by individual canine-origin LAB was also evaluated. The effects of various prebiotics on in vitro oxalate degradation by selected oxalate-degrading canine LAB was also evaluated. Canine fecal samples reduced oxalate levels by 78 +/- 12.2% (mean +/- S.D.; range: 44-97%, median: 81%). Feline results were similar, with oxalate reduction of 69.7 +/- 16.7% (mean +/- S.D.; range: 40-96%, median: 73%). Thirty-seven lactic acid bacteria were isolated from canine fecal samples. Mean oxalate degradation was 17.7 +/- 16.6% (mean +/- S.D.; range: 0-65%, median: 13%). No oxalate degradation was detected for four (11%) isolates, and 10/37 (27%) degraded less than 10% of oxalate. The effects of lactitol, arabinogalactan, guar gum, gum Arabic, inulin, maltodextrin or a commercial fructooligosaccharide (FOS) product on in vitro oxalate degradation by five canine LAB isolates were highly variable, even within the same bacterial species. Overall, in vitro degradation was significantly greater with guar gum compared to arabinogalactan (P < 0.05), gum Arabic (P < 0.05), and lactitol (P < 0.01). This study suggests that manipulation of the LAB component of the canine and feline gastrointestinal microflora may decrease intestinal oxalate, and correspondingly intestinal oxalate absorption and renal excretion, thus potentially reducing oxalate urolithiasis.

Animals↗
PubMed2002

Evaluation of immunomodulatory effects of lactic acid bacteria in turbot (Scophthalmus maximus).

In the present work, the effects of several lactic acid bacteria on the immune response of turbot (Scophthalmus maximus) macrophages have been studied both in vitro and in vivo. Out of six lactic acid bacterial strains tested, only heat-killed Lactococcus lactis significantly increased the turbot head kidney macrophage chemiluminescent (CL) response after 24 h of incubation. Nitric oxide (NO) was also significantly enhanced by this bacterium after 72 h of incubation with either viable (10(3) and 10(6) cells/ml) or heat-killed (10(6) cells/ml) bacteria. Viable Leuconostoc mesenteroides (10(6) cells/ml) was also capable of significantly increasing NO production. Since L. lactis proved to be the strain with more effects on the host immune function, further in vivo and in vitro experiments were conducted with this bacterium. The in vitro capacity of L. lactis to adhere to turbot intestinal mucus was positively confirmed. When orally administered, L. lactis significantly increased the macrophage CL response and the serum NO concentration after 7 days of daily administration. The antibacterial effect of the extracellular products from the six LAB strains against the fish-pathogenic bacterium Vibrio anguillarum was also demonstrated in vitro.

Animals↗