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PubMed1996

Cloning and expression of the Zymomonas mobilis "production of ethanol" genes in Lactobacillus casei.

This study describes the expression of the Zymomonas mobilis genes coding for pyruvate decarboxylase (pdc) and alcohol dehydrogenase (adh) in Lactobacillus casei 686. To promote transcription, the promoter and ribosome binding site (RBS) from the Lactococcus lactis subsp. lactis-derived vector, pMGE36e, were inserted upstream of the pdc gene. The former sequences were positioned such that translation of pdc was coupled to translation of an 81-base pair open reading frame terminating within the pdc initiation site. The recombinant plasmid (pRSG02) was electroporated into L. casei, and transformants were obtained. Northern analysis confirmed the production of a 3. 1-kb transcript corresponding to the predicted size of the PET operon. Western blot analyses revealed that the recombinant strain expressed both enzymes. The recombinant produced more than twice the ethanol produced by the parental L. casei strain.

Alcohol Dehydrogenase↗
PubMed2006

Probiotic Lactobacillus casei activates innate immunity via NF-kappaB and p38 MAP kinase signaling pathways.

Probiotic bacteria are microorganisms that benefit the host through improvement of the balance of intestinal microflora and possibly by augmentation of host defense systems. We examined the mechanisms for the up-regulation of innate immune responses by a probiotic Lactobacillus casei ATCC27139, in vivo. Using mouse models of systemic Listeria monocytogenes infection and MethA fibrosarcoma tumorigenesis in combination with BALB/c and SCID mice, we found that parenteral administration of L. casei ATCC27139 confers a protective effect against L. monocytogenes infection and anti-tumor activity against MethA fibrosarcoma by activation of innate immunity, while L. casei ATCC27139-J1R strains, which are J1 phage-resistant strains that have been selected from MNNG-treated clones, lacked these activities. Substantial differences between ATCC27139 and ATCC27139-J1R strains were observed in the capacity to induce innate cytokines such as TNF-alpha, IL-12, IL-18, and IFN-gamma, and pathogen-associated molecular pattern receptors, TLR2 and Nod2, by spleen cells. In addition, although phosphorylation of NF-kappaB p65 in spleen was equally enhanced in the ATCC27139- and the ATCC27139-J1R-treated groups, phosphorylation of both p38 MAPK and MAPKAPK-2 was significantly induced only by ATCC27139. Furthermore, inhibitors of NF-kappaB (sulfasalazine) and p38 MAPK (SB203580) significantly reduced cytokine production by the spleen cells of the mice treated with L. casei ATCC27139, suggesting that both NF-kappaB and p38 MAPK signaling pathways play important roles in the augmentation of innate immunity by the probiotic L. casei.

Animals↗
PubMed1974

Genetic basis of nutritional requirements in Lactobacillus casei.

In a study of the genetic basis of multiple nutritional requirements in Lactobacillus casei, systematic attempts were made to isolate mutants that can grow in the absence of a specific nutrient required by the parental organism. Such mutants have successfully been isolated with respect to seven of twelve amino acids (aspartic acid, leucine, isoleucine, lysine, methionine, serine, and threonine) and three of four vitamins (pantothenic acid, nicotinic acid, and pyridoxal) tested, after extensive screenings employing various mutagens. Mutants that can grow without tryptophan were not isolated, but those that can grow on anthranilate or indole as well as on tryptophan were obtained at a frequency expected for single-step mutations. Activity of tryptophan synthetase was demonstrated in extracts of these anthranilate-utilizing mutants, but not in the parental strain. These results suggest that the multiple nutritional requirements of L. casei are often, if not always, due to one or a few small lesions such as base substitution mutations rather than large deletions affecting the genes involved in each biosynthetic pathway. The data would also imply that many of the biosynthetic pathways that are not fully functional in L. casei were active at one time and became nonfunctional during evolution of the present species.

Adenine↗
PubMed1998

The effect of oral feeding of Lactobacillus casei strain Shirota on immunoglobulin E production in mice.

We investigated the effect of oral feeding of heat-killed Lactobacillus casei strain Shirota on immunoglobulin E (IgE) production in mice. The strain was orally administered to BALB/c mice that had been preinjected intraperitoneally with ovalbumin, and the level of IgE in serum was determined. Results indicated that the oral feeding of L. casei strain Shirota was effective in inhibiting IgE production in serum, and the IgE production in response to ovalbumin was significantly inhibited in the mice. The in vitro production of IgE by the spleen cells from mice fed L. casei strain Shirota in response to restimulation with ovalbumin was inhibited in contrast to that of spleen cells from the control group. We also examined the pattern of cytokine production by spleen cells from mice fed L. casei strain Shirota followed by restimulation with ovalbumin in vitro. In the mice fed L. casei strain Shirota, the production by the spleen cells of Th1 cell-associated cytokines, such as interferon-gamma and interleukin-2, was higher than that by the spleen cells from the control group. In contrast, the production of Th2 cell-associated cytokines, such as interleukin-4, interleukin-5, interleukin-6, and interleukin-10, by spleen cells in the group fed L. casei strain Shirota was lower than that by the cells from the control group. Furthermore, the interleukin-12 production of the spleen cells from mice fed L. casei strain Shirota was also higher than that of the control group.

Animals↗
PubMed1996

Suppressive effects of Lactobacillus casei cells, a bacterial immunostimulant, on the incidence of spontaneous thymic lymphoma in AKR mice.

The mean survival age of female AKR/J mice was significantly prolonged, the enlargement of thymus was markedly suppressed, and the proliferation of ecotropic and recombinant murine leukemia viruses (MuLV) was markedly inhibited when 8-week-old female AKR/J mice were injected intraperitoneally (i.p.) with heat-killed Lactobacillus casei cells twice weekly for 8 weeks. In contrast, such actions of heat-killed L. casei cells were not seen in 20-week-old female AKR/J mice. The leukemogenic activity of the cell-free extract of thymus from adult female AKR/J mice in newborn female AKR/J mice was drastically reduced by i.p. treatment with heat-killed L. casei cells. The difference in adjuvant effectiveness of heat-killed L. casei cells on 8- and 20-week-old animals may be dependent on the difference in the enhancing activity of the cell-mediated immune systems between the groups induced by heat-killed L. casei cells, and, as a result, on the difference in the degree of proliferation of ecotropic and recombinant MuLV in thymus, which consequently causes thymic lymphoma.

Adjuvants, Immunologic↗
PubMed1998

The effect of consumption of milk fermented by Lactobacillus casei strain Shirota on the intestinal microflora and immune parameters in humans.

OBJECTIVE: To determine the effect of consumption of milk fermented by Lactobacillus casei strain Shirota (L. casei Shirota) on the composition and metabolic activities of the intestinal microflora, and immune parameters in humans. SUBJECTS: Twenty healthy male subjects aged 40-65 years were selected. DESIGN: A placebo-controlled trial was performed in which 10 subjects were randomly assigned to a control and 10 to a treatment group. During the first and last two weeks of the 8-week study the subjects received a strictly controlled diet without fermented products. The same controlled diet was given during the intermediate 4-week test period but then the treatment group received three times daily 100 ml of fermented milk containing 10(9) CFU L. casei Shirota/ml, whereas the same amount of unfermented milk was given to the subjects in the control group. RESULTS: In comparison to the control group, the consumption of L. casei Shirota-fermented milk resulted in an increase of the Lactobacillus count in the faeces in which the administered L. casei Shirota was predominant at the level of 10(7) CFU/g wet faeces. This was associated with a significant increase in Bifidobacterium counts (P < 0.05). Some shifts in the other bacterial species were found, such as a decreased number of Clostridium; however the differences were not statistically different between the treatment and the control groups. The beta-glucuronidase and beta-glucosidase activities per 10(10) bacteria decreased significantly (P < 0.05) at the second week of the 4-week test period with the consumption of L. casei Shirota-fermented milk. Furthermore, the consumption of the fermented milk product resulted in a slight but significant increase in the moisture content of the faecal samples (P < 0.05). No treatment effects were observed for any of the immune parameters measured (including natural killer (NK) cell activity, phagocytosis and cytokine production). CONCLUSIONS: The results suggest that consumption of L. casei Shirota-fermented milk is able to modulate the composition and metabolic activity of the intestinal flora and indicate that L. casei Shirota-fermented milk does not influence the immune system of healthy immunocompetent males.

Adult↗
PubMed2006

Display of alpha-amylase on the surface of Lactobacillus casei cells by use of the PgsA anchor protein, and production of lactic acid from starch.

We developed a new cell surface engineering system based on the PgsA anchor protein from Bacillus subtilis. In this system, the N terminus of the target protein was fused to the PgsA protein and the resulting fusion protein was expressed on the cell surface. Using this new system, we constructed a novel starch-degrading strain of Lactobacillus casei by genetically displaying alpha-amylase from the Streptococcus bovis strain 148 with a FLAG peptide tag (AmyAF). Localization of the PgsA-AmyA-FLAG fusion protein on the cell surface was confirmed by immunofluorescence microscopy and flow cytometric analysis. The lactic acid bacteria which displayed AmyAF showed significantly elevated hydrolytic activity toward soluble starch. By fermentation using AmyAF-displaying L. casei cells, 50 g/liter of soluble starch was reduced to 13.7 g/liter, and 21.8 g/liter of lactic acid was produced within about 24 h. The yield in terms of grams of lactic acid produced per gram of carbohydrate utilized was 0.60 g per g of carbohydrate consumed at 24 h. Since AmyA was immobilized on the cells, cells were recovered after fermentation and used repeatedly. During repeated utilization of cells, the lactic acid yield was improved to 0.81 g per g of carbohydrate consumed at 72 h. These results indicate that efficient simultaneous saccharification and fermentation from soluble starch to lactic acid were carried out by recombinant L. casei cells with cell surface display of AmyA.

Enzymes, Immobilized↗
PubMed2000

Expression of cbsA encoding the collagen-binding S-protein of Lactobacillus crispatus JCM5810 in Lactobacillus casei ATCC 393(T).

The cbsA gene encoding the collagen-binding S-layer protein of Lactobacillus crispatus JCM5810 was expressed in L. casei ATCC 393(T). The S-protein was not retained on the surface of the recombinant bacteria but was secreted into the medium. By translational fusion of CbsA to the cell wall sorting signal of the proteinase, PrtP, of L. casei, CbsA was presented at the surface, rendering the transformants able to bind to immobilized collagens.

Bacterial Proteins↗
PubMed2005

Randomized trial of dietary fiber and Lactobacillus casei administration for prevention of colorectal tumors.

The epidemiologic evidence that dietary fiber protects against colorectal cancer is equivocal. No large-scale clinical study of the administration of Lactobacillus casei has been reported. We examined whether dietary fiber and L. casei prevented the occurrence of colorectal tumors. Subjects were 398 men and women presently free from tumor who had had at least 2 colorectal tumors removed. Subjects were randomly assigned to 4 groups administered wheat bran, L. casei, both or neither. The primary end point was the presence or absence of new colorectal tumor(s) diagnosed by colonoscopy after 2 and 4 years. Among 380 subjects who completed the study, 95, 96, 96 and 93 were assigned to the wheat bran, L. casei, both and no treatment groups, respectively. Multivariate adjusted ORs for occurrence of tumors were 1.31 (95% CI 0.87-1.98) in the wheat bran group and 0.76 (0.50-1.15) in the L. casei group compared to the control group. There was a significantly higher number of large tumors after 4 years in the wheat bran group. The occurrence rate of tumors with a grade of moderate atypia or higher was significantly lower in the group administered L. casei. No significant difference in the development of new colorectal tumors was observed with administration of either wheat bran or L. casei. However, our results suggest that L. casei prevented atypia of colorectal tumors.

Adult↗
PubMed1978

Measurement of serum folate by 75Se-selenofolate radioassay. Results of a multi-institutional clinical trial.

The authors report the multi-institutional evaluation of a radioassay for serum folate utilizing a gamma-labeled folate analog (75Se-pteroyl-L-methylselenocysteine). The assay is run as a one-step simultaneous addition at ambient temperature and is completed within 45 minutes. The assay data were reproducible within four study centers and correlated with both the Lactobacillus casei diagnostic groups and the clinical pictures.

Biological Assay↗
PubMed2001

Comparative sequence analysis of a recA gene fragment brings new evidence for a change in the taxonomy of the Lactobacillus casei group.

The taxonomic positions of species of the Lactobacillus casei group have been evaluated by sequencing and phylogenetic analysis of a 277 bp recA gene fragment. High sequence similarity between strain ATCC 393T, currently designated as the type strain of L. casei, and the type strain of Lactobacillus zeae, LMG 17315T, has been established, while L. casei ATCC 334 and Lactobacillus paracasei NCDO 151T form a single phylogenetic group. The taxonomic status of species and strains at issue is discussed.

DNA, Bacterial↗
PubMed1980

Factors affecting the quaternary structure of the allosteric L-lactate dehydrogenase from Lactobacillus casei and Lactobacillus curvatus as investigated by hybridization and ultracentrifugation.

The allosteric L-lactate dehydrogenases of Lactobacillus curvatus and Lactobacillus casei exist in the tetrameric from (molecular weight about 145 000) at pH 5.0--5.5 even in the absence of the effectors Mn2+ and Fru(1,6)P2 (fructose 1,6-bisphosphate), but undergo reversible dissociation to monomers (molecular weight about 35 000) at higher pH values or in the presence of urea. In the range between pH 5.5 (tetrameric state) and pH 7.4 (monomeric state) the L. curvatus L-lactate dehydrogenase exists in a dissociation-association equilibrium comprising tetramers, dimers and monomers as indicated by the Sc20,w values and the results of hybridization experiments. The simultaneous addition of both effectors [Mn2+ and Fru(1,6)P2] at pH 7.4, however, resulted in the stabilization of the tetrameric form. The addition of Fru(1,6)P2 alone at pH 7.4 had almost no influence on the quarternary structure, whereas the addition of Mn2+, as well as that of NADH, largely prevented dissociation. The L-lactate dehydrogenase of L. casei showed similar properties, although the enzyme dissociates only at about pH greater than or equal to 7.8. As in the case of the L. curvatus enzyme, Fru(1,6)P2 has no influence on the pH-dependent dissociation of the L. casei enzyme, whereas Mn2+ stabilizes the tetrameric structure. Reconstitution of a mixture of the two dissociated enzymes results in the formation of all statistically possible, enzymatically active hybrids. No hybridization between the allosteric enzymes from L. casei and L. curvatus and the non-allosteric ones of Lactobacillus plantarum and Lactobacillus acidophilus was observed.

Allosteric Regulation↗
PubMed1964

FREEZING-OUT TECHNIQUE APPLIED TO THE CONCENTRATION OF BIOLOGICALLY ACTIVE MATERIALS.

When applied to a dilute solution of folic acid and glucose, a freezing-out (with agitation) technique was shown to be an effective method of achieving a 20-fold reduction in volume with a loss of 10% of the active material being concentrated. Concentration of a stimulatory factor for Lactobacillus casei produced by Candida albicans in a complex medium was limited by the total solute concentration. Salts in the medium were concentrated to levels inhibitory for L. casei. The process is not selective and all solutes are concentrated.

Bacteriological Techniques↗
PubMedDate not supplied

Effect of aeration on the production of carotenoid pigments by Rhodotorula rubra-lactobacillus casei subsp. casei co-cultures in whey ultrafiltrate.

Under intensive aeration (1.3 l/l min) the associated growth of Rhodotorula rubra GED2 and Lactobacillus casei subsp. casei in cheese whey ultrafiltrate (55 g lactose/l) proceeded effectively for both cultures with production of maximum carotenoids (12.4 mg/l culture fluid). For maximum amount of carotenoids synthesized in the cell, the yeast required more intensive aeration than the aeration needed for synthesis of maximum concentration of dry cells. Maximum concentration of carotenoids in the cell (0.49 mg/g dry cells) was registered with air flow rate at 1.3 l/l min, and of dry cells (27.0 g/l) at 1.0 l/l min. An important characteristic of carotenogenesis by Rhodotorula rubra GED2 + Lactobacillus casei subsp. casei was established--the intensive aeration (above 1.0 l/l min) stimulated beta-carotene synthesis (60% of total carotenoids).

Aerobiosis↗
PubMed1979

Vitamin B2 activity of 7,8-dimethyl-10-(2,3,4-trihydroxy-4-formylbutyl)isoalloxazine in Lactobacillus casei.

The microbial activities of vitamin B2-aldehyde and vitamin B2-acid, produced by Schizophyllum commune, a Basidiomycete, were studied. Lactobacillus casei ATCC No. 7469 was used as a test microorganism. B2-aldehyde exhibited a good response curve in the growth of L. casei. B2-acid had neither a stimulatory nor an inhibitory effect on the growth. When B2-aldehyde was incubated with the homogenate of L. casei, it was converted to riboflavin. The flavin formed from B2-aldehyde by the homogenate not only exhibited an equivalent response curve to authentic riboflavin in the growth of L. casei, but also showed the same Rf value as authentic riboflavin in any paper chromatogram, as far as tested. Hence, the microbial activity of B2-aldehyde for L. casei seems to be ascribable to riboflavin which is a reduction product of B2-aldehyde.

Dose-Response Relationship, Drug↗
PubMed1993

Antimicrobial compounds from Lactobacillus casei and Lactobacillus helveticus.

Three strains of Lactobacillus casei and one of Lactobacillus helveticus were examined for antagonistic activity toward twenty five indicator strains of different species. Under conditions eliminating the effects of organic acid and hydrogen peroxide, culture supernatants of all the Lactobacillus strains exhibited a wide spectrum of inhibitory activity toward microorganisms of different genera. The inhibitory compound secreted by one strain of L. casei was active against Clostridium tyrobutyricum. The active components were insensitive to proteolytic enzyme and heat treatment.

Anti-Bacterial Agents↗