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PubMed2000

Molecular analysis of mutated Lactobacillus acidophilus promoter-like sequence P15.

The promoter-like sequence P15 that was previously cloned from the chromosome of Lactobacillus acidophilus ATCC 4356 is active in Lactobacillus reuteri, Lactobacillus plantarum, Lactobacillus acidophilus, and Escherichia coli, but not in Lactococcus lactis. N-methyl-N-nitroso-N-guanidine (MNNG) mutagenesis of P15 was used to select for a promoter active in L. lactis MG1363. Molecular analysis of the mutated promoter (designated P16) revealed a 90 bp deletion and a T-->A transversion. This deletion, in combination with the addition to the transversion, created a promoter with putative -35 and -10 hexamers identical to the consensus promoter sequence found in E. coli and Bacillus subtilis vegetative promoters. The activity of P16 was measured by its ability to promote chloramphenicol resistance in different bacteria when inserted in the promoter-probe plasmid pBV5030 (designated pLA16). The MIC of chloramphenicol in L. lactis, L. reuteri, L. plantarum, E. coli, and L. acidophilus harbouring pLA16 were 30, 170, 180, > 500, and 3 micrograms/mL, respectively. This represents an increase in promoter activity compared to P15 in L. reuteri of 3-fold, in L. plantarum of 9-fold, and in E. coli of at least 2.5-fold, but a decrease in L. acidophilus of 7-fold.

Anti-Bacterial Agents↗
PubMed1990

[Penicillin-binding proteins of various strains of Lactobacillus].

Sensitivity of different species of Lactobacillus i.e. L. casei, L. plantarum, L. acidophillus, L. buchneri, L. jugurti and others to penicillins and cephalosporins of various generations was studied. Penicillin binding proteins (PBPs) of the Lactobacillus species were specified. It was shown that the number of PBPs depended on the Lactobacillus species. L. casei had the least number of PBPs (4) and L. brevis had the highest number of PBPs (11). Competition of 14C-benzylpenicillin with ampicillin, cefotaxime, ceftizoxime and cefoperazone for binding to separate PBPs in three strains of different Lactobacillus species was investigated.

Ampicillin↗
PubMed2001

Quality control Lactobacillus strains for use with the API 50CH and API ZYM systems at 37 degrees C.

The API 50CH and API ZYM systems fulfil an important role in the polyphasic taxonomic identification of lactobacilli. When the API 50CH fermentation profile of the quality control Lactobacillus casei var. alactosus (Lb. paracasei subsp. paracasei) strain NCFB 206 was determined at 37 degrees C, it was found to differ from that determined at 30 degrees C by BioMéreiux SA (Montalieu Vercieu, France) and the National Collection of Food Bacteria (Aberdeen, Scotland). In addition, the API 50CH fermentation and API ZYM profiles of Lb. casei strain ATCC 334T determined at 37 degrees C differed from those determined at 30 degrees C by Lee and Simard (1984). Strains NCFB 206 and ATCC 334T were thus assumed to exhibit temperature-dependent variation in fermentation profile, a phenomenon recently described by Nigatu et al. (2000). In contrast, Lb. rhamnosus strain ATCC 243T did not exhibit temperature-dependent variation in fermentation profile. Moreover, the fermentation profile obtained at 37 degrees C differed in only one respect (positive beta-gentiobiose utilisation) from that published by Collins et al. (1989). In addition, Lactobacillus strain GG produced a stable and reproducible API ZYM profile at 37 degrees C, although some variation in the level of enzyme activity was evident. Thus, strain NCFB 206 was replaced by strain ATCC 243T as the quality control strain of choice for use with the API 50CH fermentation system, and Lactobacillus strain GG adopted for use as a quality control strain with the API ZYM system for strain identification of lactobacilli at 37 degrees C. The API 50CH and API ZYM profiles of the commercially important Lactobacillus strains NCFB 1748, GG, KLD, F19, and ACA-DC 212.3 were determined at 37 degrees C after anaerobic growth in MRS broth. The fermentation and enzyme profiles of strain NCFB 1748 were almost identical to those of Lb. crispatus ATCC 33820T, those of strain GG were found to be more similar to those of Lb. rhamnosus strain 243T than Lb. zeae strain ATCC 15820T, those of strain KLD were most similar to those of Lb. fermentum DSM 20052T, while those of strains F19 and ACA-DC 212.3 were similar to those of Lb. casei strain ATCC 334T.

Bacterial Typing Techniques↗
PubMed2004

Metabolic activities of Lactobacillus spp. strains isolated from kefir.

A total of 21 strains of Lactobacillus species were isolated from Turkish kefir samples, in order to select the most suitable strains according to their metabolic activities including probiotic properties. As a result of the identification tests, 21 Lactobacillus isolates were identified as L. acidophilus (4%), L. helveticus (9%), L. brevis (9%), L. bulgaricus (14%), L. plantarum (14%), L. casei (19%) and L. lactis (28%). The amount of produced lactic acid, hydrogen peroxide, proteolytic activity, and acetaldehyde productions of Lactobacillus spp. were determined. Different amounts of lactic acid were produced by strains studies; however, lactic acid levels were 1.7-11.4 mg/mL. All strains produced hydrogen peroxide. L. bulgaricus Z14L strain showed no proteolytic activity, L. casei Z6L strain produced the maximum amount (0.16 mg/mL) of proteolytic activity. Acetaldehyde concentration produced in Lactobacillus strains ranged between 0.88-3.52 microg/mL.

Acetaldehyde↗
PubMed1997

Effect of Lactobacillus supplementation with and without arginine on liver damage and bacterial translocation in an acute liver injury model in the rat.

In acute liver failure following hepatitis, toxic insults, or after major liver surgery, there is an increased bacterial translocation from the gut. This may explain some of the infectious complications seen in these conditions. To elucidate mechanisms and find possible preventive measures, we investigated the effect of rectal administration of arginine and probiotic bacteria (Lactobacillus spp.) on bacterial translocation and the extent of liver failure. Sprague-Dawley rats were used and five different Lactobacillus strains (Lb. reuteri R2LC, Lb. rhamnosus DSM 6594 (= strain 271), Lb. plantarum DSM 9843 (= strain 299v), Lb. fermentum 8704:3 (= strain 245), and Lb. reuteri (= strain 108) were administered rectally once daily for 8 days with and without 2% arginine. Acute liver injury (ALI) was induced on the eighth day by intraperitoneal injection of D-galactosamine (1.1 g/kg body weight), and samples were collected after 24 and 48 hours. Bacterial translocation was evaluated by bacterial culture from portal and arterial blood, mesenteric lymph nodes, and liver tissue. Liver enzymes and bilirubin were evaluated in the serum. The bacterial load in the cecum and colon was determined and the liver histopathological changes were studied. There was no mortality at any time. The liver enzymes and bilirubin decreased in some of the groups supplemented with lactobacilli with and without arginine compared with the ALI control group. The incidence of bacterial translocation and the number of the translocated bacteria decreased significantly in some of the supplemented groups. Lb. plantarum + arginine administration significantly reduced the level of the released liver enzymes, hepatocellular necrosis and inflammatory cell infiltration, bacterial translocation, and the number of Enterobacteriaceae in the cecum and colon. Rectal administration of different Lactobacillus strains with and without arginine in an ALI model significantly modulates the extent of the liver failure and reduces bacterial translocation. Lb. plantarum DSM 9843 (= strain 299v) with or without arginine seemed superior to the other Lactobacillus strains. The beneficial effect of arginine administration alone indicates a possible role of nitric oxide and polyamines in this process, and the lactobacilli may execute their action via the same mechanisms or via bacterial antagonism and/or enhancement of systemic and intestinal mucosal immunity.

Alanine Transaminase↗
PubMed1995

Studies on bacteriocinogenic Lactobacillus isolates from selected Nigerian fermented foods.

Ten bacteriocin-producing (bacteriocinogenic) Lactobacillus isolates obtained from three Nigerian fermented foods namely: kenkey, ogi and wara were tested against the following indicator organisms: Lactobacillus plantarum and food borne pathogens comprising enterotoxigenic Escherichia coli, enterohaemorrhagic Escherichia coli, Serratia, Pseudomonas, Vibrio cholerae, Aeromonas sobria, Aeromonas cavice, Salmonella typhimurium, Plesiomonas shigelloides and Staphylococcus aureus. All the bacteriocinogenic Lactobacillus were found to inhibit L. plantarum while some inhibited some of the food borne pathogens listed above. The antimicrobial activities of bacteriocins from L. plantarum KKY12 and L. casei OGM12 were caused by proteins detectable in the culture liquids. They are designated Plantacin N and Caseicin A and they have narrow antimicrobial spectra. Plantacin N from L. plantarum KKY12 was active against L. plantarum, Pseudomonas, Aeromonas sobria and Aeromonas cavice whereas Caseicin A from L. casei OGM12 inhibited L. plantarum, enterotoxigenic Escherichia coli and Vibrio cholerae. Caseicin A is stable at 121 degrees C/15 mins, and both are inactivated by proteolytic enzymes. The bacteriocinogenic properties of the local isolates of Lactobacillus can help to reduce hygienic risk and the spoilage of fermented foods.

Bacteriocins↗
PubMed2001

The S-layer protein of Lactobacillus acidophilus ATCC 4356: identification and characterisation of domains responsible for S-protein assembly and cell wall binding.

Lactobacillus acidophilus, like many other bacteria, harbors a surface layer consisting of a protein (S(A)-protein) of 43 kDa. S(A)-protein could be readily extracted and crystallized in vitro into large crystalline patches on lipid monolayers with a net negative charge but not on lipids with a net neutral charge. Reconstruction of the S-layer from crystals grown on dioleoylphosphatidylserine indicated an oblique lattice with unit cell dimensions (a=118 A; b=53 A, and gamma=102 degrees ) resembling those determined for the S-layer of Lactobacillus helveticus ATCC 12046. Sequence comparison of S(A)-protein with S-proteins from L. helveticus, Lactobacillus crispatus and the S-proteins encoded by the silent S-protein genes from L. acidophilus and L. crispatus suggested the presence of two domains, one comprising the N-terminal two-thirds (SAN), and another made up of the C-terminal one-third (SAC) of S(A)-protein. The sequence of the N-terminal domains is variable, while that of the C-terminal domain is highly conserved in the S-proteins of these organisms and contains a tandem repeat. Proteolytic digestion of S(A)-protein showed that SAN was protease-resistant, suggesting a compact structure. SAC was rapidly degraded by proteases and therefore probably has a more accessible structure. DNA sequences encoding SAN or Green Fluorescent Protein fused to SAC (GFP-SAC) were efficiently expressed in Escherichia coli. Purified SAN could crystallize into mono and multi-layered crystals with the same lattice parameters as those found for authentic S(A)-protein. A calculated S(A)-protein minus SAN density-difference map revealed the probable location, in projection, of the SAC domain, which is missing from the truncated SAN peptide. The GFP-SAC fusion product was shown to bind to the surface of L. acidophilus, L. helveticus and L. crispatus cells from which the S-layer had been removed, but not to non-stripped cells or to Lactobacillus casei.

Amino Acid Sequence↗
PubMed1996

The effect of endotoxin and Lactobacillus pretreatment on peritoneal macrophage behavior in acute liver injury in rat.

The effect of endotoxin and Lactobacillus R2LC pretreatment in acute liver injury, induced by D-galactosamine was studied. Administration of D-galactosamine resulted in much higher luminescent activity than the control (49.24 mV vs 19.75 mV), while there was no change detected on the metabolic response to phorbol-12-myristate-13-acetate (PMA) stimulation in the calorimeter. Pretreatment of animals with intraperitoneal administration of heat-killed Lactobacillus resulted in higher oxygen free radical production (105.46 mV) and a much higher metabolic response to PMA in microcalorimeter (24.63 pW per cell vs 13.03 in the control). On the other hand pretreatment with endotoxin resulted in higher luminometric response to PMA compared to liver injury group (65.87 mV), and no response in the microcalorimeter at all. Phagocytic activity was decreased from 86 to 59% after administration of D-galactosamine, and was not significantly influenced by any of the pretreatment modalities. This experiment showed that pretreatment with Lactobacillus resulted in increased macrophage metabolic activity, while endotoxin pretreatment rendered the macrophages unresponsive to subsequent stimulation. These findings may explain why pretreatment with endotoxin is beneficial in acute liver injury induced by D-galactosamine, but not with gram-positive bacteria including Lactobacillus.

Animals↗
PubMed2000

Comparative genomics of the late gene cluster from Lactobacillus phages.

Three prophage sequences were identified in the Lactobacillus johnsoni strain NCC533. Prophage Lj965 predicted a gene map very similar to those of pac-site Streptococcus thermophilus phages over its DNA packaging and head and tail morphogenesis modules. Sequence similarity linked the putative DNA packaging and head morphogenesis genes at the protein level. Prophage Lj965/S. thermophilus phage Sfi11/Lactococcus lactis phage TP901-1 on one hand and Lactobacillus delbrueckii phage LL-H/Lactobacillus plantarum phage phig1e/Listeria monocytogenes phage A118 on the other hand defined two sublines of structural gene clusters in pac-site Siphoviridae from low-GC Gram-positive bacteria. Bacillus subtilis phage SPP1 linked both sublines. The putative major head and tail proteins from Lj965 shared weak sequence similarity with phages from Gram-negative bacteria. A clearly independent line of structural genes in Siphoviridae from low-GC Gram-positive bacteria is defined by temperate cos-site phages including Lactobacillus gasseri phage adh, which also shared sequence similarity with phage D3 infecting a Gram-negative bacterium. A phylogenetic tree analysis demonstrated that the ClpP-like protein identified in four cos-site Siphoviridae from Lactobacillus, Lactococcus, Streptococcus, and Pseudomonas showed graded sequence relationships. The tree suggested that the ClpP-like proteins from the phages were not acquired by horizontal gene transfer from their corresponding bacterial hosts.

Amino Acid Sequence↗
PubMedDate not supplied

Effect of Lactobacillus supplementation on immune status of malnourished pre-school children.

The present study was undertaken to assess the effect of Lactobacillus supplementation on immune response of pre-school children. Thirty malnourished (grade I and grade II) pre-school (3-5 years old) children were selected for the study. These were further categorized into three groups 'A', 'B' and 'C', each group comprising of 10 individuals. Groups 'A' and 'B' were given lactobacillus supplementation 1.0 x 10(8) million viable spores/day/child and 2.0 x 10(8) million of viable spores/day/child for 90 days respectively. Group 'C' served as control. Serum adenosine deaminase (ADA) which is an important immuno enzyme marker for assessing lymphocyte function and proliferation was determined at different intervals. The results revealed that lactobacillus supplementation at level of 1.0 x 10(8) million viable spores/day/child for 15 days along with regular diet significantly improved the ADA levels of pre-school children indicating therapeutic value of lactobacillus as supplementation to malnourished pre-school children.

Adenosine Deaminase↗
PubMed2005

Identification of Lactobacillus ruminus SPM0211 isolated from healthy Koreans and its antimicrobial activity against some pathogens.

The intestinal microbiota are important to the host with regard to resistance they impart against bacterial infections and their involvement in mediating metabolic functions. Lactic acid producing bacteria such as Lactobacillus play an important physiological role in these matters. The aim of the present study was to isolate Lactobacillus sp. that inhibits enteric pathogens. Initially, 17 isolates from healthy Koreans were collected on Lactobacillus selective medium. Resistance of the isolates to antibiotics including rifampicin, streptomycin, clindamycin and vancomycin was measured. One of the isolate was identified as Lactobacillus ruminus on the basis of bacterial cell morphology, cultural characteristic and biochemical characteristics, 16S rRNA sequence analysis and PCR-RAPD. Antimicrobial activity of the bacterium against Vancomycin Intermediate Resistant Staphylococcus aureus (VISA) and Vancomycin-Resistant Enterococci (VRE) was measured. About 10(4) cells of VISA or VRE were mixed with 1, 5, and 9 mL of L. ruminus SPM 0211 and the final volume was adjusted to 10 mL with brain heart infusion (BHI) broth. The cell suspension was incubated for 3, 6, 9, and 24 h, serially diluted and then plated on BHI agar plates. As numbers of L. ruminus SPM 0211 were increased, viable cell count of VISA and VRE decreased. The strongest antimicrobial activity of SPM 0211 was observed after 9 h incubation in any mixture, almost completely inhibiting the growth of these two bacteria. The results suggest that the freshly isolated L. ruminus SPM 0211 may be used as a pro-biotic microbe that prevents the colonization of enteric pathogens and can thereby promote good gastrointestinal health.

Adult↗
PubMed1991

Some taxonomical characteristics of encapsulated Lactobacillus sp. KPB-167B isolated from kefir grains and characterization of its extracellular polysaccharide.

A capsular polysaccharide-producing strain KPB-167B isolated from kefir grains was identified as a homofermentative Lactobacillus. The carbohydrate fermentation pattern and DNA base composition of the strain were different from those of other capsular Lactobacillus species previously isolated from kefir grains. The polysaccharide produced by Lactobacillus sp. KPB-167B was found similar to kefiran by 13C-NMR and methylation analysis. Lactobacillus sp. KPB-167B could grow and produce capsular polysaccharide in MRSL medium with better yield than L. kefiranofaciens, which suggested that it is suitable for kefiran production.

Animals↗
PubMed1988

Plasmid-linked maltose utilization in Lactobacillus ssp.

Five strains of Lactobacillus plantarum and 4 strains of Lactobacillus ssp. isolated from fresh meat contained between 1 and 5 plasmids ranging in Mr from 1.3 to 49 MDa. Plasmid-curing studies suggested that maltose utilization is associated with a 49 MDa plasmid (pML291) in Lactobacillus sp. DB29 and 34.5 MDa plasmids in Lactobacillus ssp. DB27, DB28 and DB31. Restriction digestion of pML291 and a putative plasmid deletion derivative, pML292, isolated from a maltose negative mutant of DB29, generated common restriction fragments. Southern blot DNA-DNA hybridization using pML 291 as a probe indicated that there is strong homology between putative maltose plasmids.

Blotting, Southern↗
PubMedDate not supplied

Oral administration of TNP-Lactobacillus conjugates in mice: a model for evaluation of mucosal and systemic immune responses and memory formation elicited by transformed lactobacilli.

Safe live vector systems are being developed for oral delivery of antigens. A transformation system for indigenous Lactobacillus species of the gastrointestinal tract is described. Model systems were set up to evaluate immune responses. Orally administered trinitrophenylized (TNP) Lactobacillus were examined for their ability to induce immunological memory formation via determination of specific antibody titres in serum. We demonstrate a direct correlation between the level of systemic memory formation, as revealed by specific anti-TNP IgG serum antibodies, and the TNP substitution ratio of the Lactobacillus suspension used for oral priming. The specific IgG anti-TNP serum titres were comparable to or even higher than the titres of parental intraperitoneally primed animals. These results demonstrate the feasibility of using orally administered antigen-Lactobacillus as a future approach to vaccination.

Administration, Oral↗
PubMed2005

Role of lactobacillus cell surface hydrophobicity as probed by AFM in adhesion to surfaces at low and high ionic strength.

The S-layer present at the outermost cell surface of some lactobacillus species is known to convey hydrophobicity to the lactobacillus cell surface. Yet, it is commonly found that adhesion of lactobacilli to solid substrata does not proceed according to expectations based on cell surface hydrophobicity. In this paper, the role of cell surface hydrophobicity of two lactobacillus strains with and without a surface layer protein (SLP) layer has been investigated with regard to their adhesion to hydrophobically or hydrophilically functionalized glass surfaces under well-defined flow conditions and in low and high ionic strength suspensions. Similarly, the interaction of the lactobacilli with similarly functionalized atomic force microscope (AFM) tips was measured. In a low ionic strength suspension, both lactobacillus strains show higher initial deposition rates to hydrophobic glass than to hydrophilic glass, whereas in a high ionic strength suspension no clear influence of cell surface hydrophobicity on adhesion is observed. Independent of ionic strength, however, AFM detects stronger interaction forces when both bacteria and tip are hydrophobic or hydrophilic than when bacteria and tip have opposite hydrophobicities. This suggest that the interaction develops in a different way when a bacterium is forced into contact with the tip surface, like in AFM, as compared with contacts developing between a cell surface and a macroscopic substratum under flow. In addition, the distance dependence of the total Gibbs energy of interaction could only be qualitatively correlated with bacterial deposition and desorption in the parallel plate flow chamber.

Animals↗
PubMed2005

Lactobacillus surface layers and their applications.

Surface (S-) layers are crystalline arrays of proteinaceous subunits present as the outermost component of cell wall in several species of the genus Lactobacillus, as well as in many other bacteria and Archaea. Despite the high similarity of the amino acid composition of all known S-layer proteins, the overall sequence similarity is, however, surprisingly small even between the Lactobacillus S-layer proteins. In addition, the typical characteristics of Lactobacillus S-layer proteins, distinguishing them from other S-layer proteins, are small size and high-predicted pI value. Several lactobacilli possess multiple S-layer protein genes, which can be differentially or simultaneously expressed. To date, the characterized functions of Lactobacillus S-layers are involved in mediating adhesion to different host tissues. A few applications for the S-layer proteins of lactobacilli already exist, including their use as antigen delivery vehicles.

Bacterial Outer Membrane Proteins↗
PubMed2005

Effect of lactobacillus adjunct cultures on the microbiological and physicochemical characteristics of Roncal-type ewes'-milk cheese.

The effect of two different experimental adjunct cultures composed of native facultatively heterofermentative lactobacilli (FHL) on the development of various groups of micro-organisms in Roncal-type ewes' milk cheese was studied. Four cheese batches were manufactured from raw milk (C), pasteurized milk (P), pasteurized milk and an adjunct culture of Lactobacillus paracasei (PP); and pasteurized milk and adjunct culture of Lactobacillus paracasei plus Lactobacillus plantarum (PPP). Retention of the two adjunct cultures in the cheeses was good, and population levels remained constant at around 10(7) cfu g(-1) of cheese throughout ripening. Levels of Enterobacteriaceae and enterococci fell off more abruptly in the batches made with the Lactobacillus adjunct cultures, suggesting competition between the added lactobacilli and those groups of micro-organisms. The inhibitory effect was greater for the adjunct culture composed of L. paracasei plus L. plantarum. Lactococcal levels were higher in the batches made with added FHL, which may be indicative of a synergistic effect between these two groups.

Animals↗
PubMed2005

Characterization of Lactobacillus strains and monitoring by RAPD-PCR in controlled fermentations of "Almagro" eggplants.

The characterization of 23 Lactobacillus strains was performed. The strains were assayed for biogenic amine-forming capacity, hydrogen peroxide production, pectin esterase, cellulase and polygalacturonase production, growth rate, acidifying capacity and salt tolerance. Three strains were selected which belonged to the species, Lactobacillus brevis, Lactobacillus plantarum and Lactobacillus fermentum. Different starter cultures prepared as combinations of these three strains were assayed in pilot scale fermentations and Randomly Amplified Polymorphic DNA (RAPD) analysis, using a previously selected random primer, was applied for monitoring the inoculated strains. The course of fermentations was similar in all batches but sensorial analysis of eggplants fermented using a mixed culture of the three strains displayed the best results, and no differences were obtained when compared with commercial eggplants.

Biogenic Amines↗