| transport and metabolism of vitamin b6 in lactic acid bacteria. | streptococcus faecalis 8043 concentrates extracellular 3hpyridoxal or 3hpyridoxamine primarily as the corresponding 5'-phosphates. accumulation of pyridoxamine requires an exogenous energy source and is inhibited by glycolysis inhibitors. a membrane potential is not required for transport of pyridoxamine, and an artificially generated potential does not drive uptake in this organism. based on this and other evidence, it is concluded that s. faecalis accumulates pyridoxamine by facilitated diffus ... | 1977 | 14135 |
| organization and nucleotide sequence of the glutamine synthetase (glna) gene from lactobacillus delbrueckii subsp. bulgaricus. | a 3.3-kb bamhi fragment of lactobacillus delbrueckii subsp. bulgaricus dna was cloned and sequenced. it complements an escherichia coli glna deletion strain and hybridizes strongly to a dna containing the bacillus subtilis glna gene. dna sequence analysis of the l. delbrueckii subsp. bulgaricus dna showed it to contain the glna gene encoding class i glutamine synthetase, as judged by extensive homology with other prokaryotic glna genes. the sequence suggests that the enzyme encoded in this gene ... | 1992 | 1359838 |
| cell-wall-associated proteinase of lactobacillus delbrueckii subsp. bulgaricus cnrz 397: differential extraction, purification and properties of the enzyme. | whole cells of lactobacillus delbrueckii subsp. bulgaricus cnrz 397 were able to hydrolyse alpha- and beta-caseins. irrespective of the growth medium used, milk or de man-rogosa-sharpe (mrs) broth, identical patterns of alpha- and beta-casein hydrolytic products, respectively, were visualized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. a soluble proteinase present in cell-wall extracts was active on caseins and displayed the same hydrolytic patterns as whole cells. it was puri ... | 1991 | 1368107 |
| m13 dna fingerprinting, a new tool for classification and identification of lactobacillus spp. | the optimal conditions for the application of m13 dna fingerprinting to the genus lactobacillus were determined. comparative fingerprint analysis of representative strains of lactobacillus delbrueckii subsp. delbrueckii, lact. delbrueckii subsp. lactis, lact. delbrueckii subsp. bulgaricus, lact. helveticus and lact. casei permitted the differentiation of species, subspecies and individual strains and the quantitative determination of their genetic relatedness. the results confirm the high specif ... | 1992 | 1429311 |
| jenseniin g, a heat-stable bacteriocin produced by propionibacterium jensenii p126. | the genus propionibacterium includes cutaneous species typically found on human skin and the dairy or classical species (propionibacterium freudenreichii, p. jensenii, p. thoenii, and p. acidipropionici) used industrially for the production of swiss cheese and propionic acid. grinstead (1989, m.s. thesis, iowa state university, ames) has previously observed that some dairy propionibacteria inhibit other species in the classical grouping. we further investigated the inhibitor(s) produced by p. je ... | 1992 | 1539976 |
| lactobacilli and azoreductase activity in the murine cecum. | azoreductase activity in the ceca of mice lacking lactobacilli as members of the normal microflora (reconstituted-lactobacillus-free [rlf] mice) was compared with that of rlf mice whose gastrointestinal tracts were colonized by strains of lactobacillus delbrueckii and lactobacillus fermentum. azoreductase activity was 31% lower in the ceca of mice colonized by lactobacilli. | 1991 | 1785939 |
| purification and properties of the phosphofructokinase from lactobacillus bulgaricus. a non-allosteric analog of the enzyme from escherichia coli. | phosphofructokinase, the enzyme which catalyzes the conversion of fructose 6-phosphate into fructose 1,6-bisphosphate in lactobacillus bulgaricus (lactobacillus delbrueckii, subspecies bulgaricus) has been purified to homogeneity and some of its structural and functional properties have been studied. the enzyme is a tetramer composed of four 35-kda subunits. its n-terminal sequence determined on 38 residues is homologous to those of the major allosteric enzymes from escherichia coli and bacillus ... | 1991 | 1828763 |
| changes in chemical composition and sensory qualities of peanut milk fermented with lactic acid bacteria. | the effects of fermentation of aqueous extracts of peanuts (peanut milk) with lactobacillus delbrueckii ssp. bulgaricus and streptococcus salivarius ssp. thermophilus, separately and in combination, on selected chemical and sensory qualities were investigated. changes in ph, titratable acidity and viable cell populations indicated that there was a synergistic interaction between l. delbrueckii ssp. bulgaricus and s. salivarius ssp. thermophilus during fermentation. analysis of headspace volatile ... | 1991 | 1911084 |
| cloning of the d-lactate dehydrogenase gene from lactobacillus delbrueckii subsp. bulgaricus by complementation in escherichia coli. | a strain of escherichia coli (fmj144) deficient for pyruvate formate lyase and lactate dehydrogenase (ldh) was complemented with a genomic dna library from lactobacillus delbrueckii subsp. bulgaricus. one positive cloned showed ldh activity and production of d(-)lactate was demonstrated. the nucleotide sequence of the d-ldh gene (ldha) revealed the spontaneous insertion of an e. coli insertion sequence is2 upstream of the gene coding region. the open reading frame encoded a 333-amino acid protei ... | 1991 | 1915894 |
| strains and species of lactic acid bacteria in fermented milks (yogurts): effect on in vivo lactose digestion. | lactose in yogurt with live bacteria is better tolerated than lactose in other dairy foods, partly because of the activity of microbial beta-galactosidase (beta-gal), which digests lactose in vivo. to evaluate the ability of different strains and species of lactic acid bacteria to digest lactose in vivo, yogurts (containing mixtures of strains of streptococcus salivarius subsp thermophilus and lactobacillus delbrueckii subsp bulgaricus) and fermented milks (containing individual species of s the ... | 1991 | 1957819 |
| cloning, expression and sequence analysis of an endolysin-encoding gene of lactobacillus bulgaricus bacteriophage mv1. | the lysa gene specifying an endolysin of lactobacillus delbrueckii subsp. bulgaricus bacteriophage mv1, was cloned and expressed in escherichia coli. the 4.05-kb restriction fragment containing this gene was analysed by restriction and deletion mapping, and by subcloning. the nucleotide sequence of a 1150-bp fragment coding for an active lysin was determined. the lysa gene consists of 585 bp and codes for a protein of a deduced mr of 21,120, which agrees with the size based on in vivo transcript ... | 1990 | 2227453 |
| presence of an l(+)-lactate dehydrogenase in cells of lactobacillus delbrueckii ssp. bulgaricus. | lactobacillus delbrueckii ssp. bulgaricus atcc 11842 was cultured in a chemostat and growth conditions were varied as required. synthesis of l(+)-lactate was observed in all cases as well as activity of l(+)-lactate dehydrogenase in cell-free extracts. this enzyme was responsible for the formation of the l(+) isomer of lactate, since a lactate racemase was not present. | 1989 | 2504294 |
| biotin-labeled plasmid dna probes for detection of epithelium-associated strains of lactobacilli. | biotin-labeled dna probes prepared from whole plasmids (5.5 and 4.8 kilobases) of two lactobacillus strains (lactobacillus delbrueckii 21 and lactobacillus reuteri 100-23) were used to detect the homologous bacteria in microtome-cryostat-prepared sections of murine forestomach. the forestomach sections were incubated on nylon filter membranes placed on agar plates and, after lysis of the lactobacillus cells and denaturation of their dna, were used in hybridization experiments with the strain-spe ... | 1989 | 2719480 |
| nucleotide sequence of a lactobacillus delbrueckii gene encoding a minor (ucg) trna(ser). | | 1989 | 2922296 |
| microbiological assay of blood serum for the vitamin b12 status of dairy cows. | four vitamin b12 assays were compared using blood sera from friesian cows on winter diets or grazing. in herd 1, ten animals were blood-sampled three times at monthly intervals and the vitamin b12 concentration of the sera determined by the poteriochromonas malhamensis and lactobacillus delbrueckii assays. at all three sampling dates the results produced by the p. malhamensis assay were significantly greater than those produced by the l. delbrueckii assay. cows in herd 2 were divided into two gr ... | 1987 | 3693627 |
| nucleic acids of species of lactobacillus. | nucleic acid composition of 17 cultures representing the type or neotype strains of 15 named lactobacillus species was studied. nucleic acid characterization of these isolates was accompanied by a comparative study of conventional phenotypic reactions. the overall guanine plus cytosine mean deoxyribonucleic acid base composition ranged from 33 to 50% and genome sizes varied between 700 and 1500 x 10(6) daltons. sporolactobacillus inulinus contained 2500 x 10(6) daltons of chromosomal deoxyribonu ... | 1985 | 3939582 |
| effect of certain cations on the growth of lactobacillus lactis and lactobacillus delbrueckii. 3. the influence of ca++, fe++, cu++ ions. | | 1965 | 4159112 |
| persistence of aflatoxin during the fermentation of soy sauce. | aflatoxin was produced by aspergillus parasiticus nrrl 2999 but not by a. oryzae during fermentation of soy sauce. little aflatoxin was degraded within 6 weeks unless lactobacillus delbrueckii also was present. | 1973 | 4736791 |
| chemical characterization of wines fermented with various malo-lactic bacteria. | six malo-lactic strains of lactic acid bacteria were isolated from california wines and identified as lactobacillus delbrueckii, l. buchneri, l. brevis, leuconostoc citrovorum, and two strains of pediococcus cerevisiae. malo-lactic fermentation was induced in separate lots of wine by inoculation of each lot with one of the strains of bacteria. malo-lactic fermentation had occurred in each inoculated wine within 2 months. the resultant wines were subjected to chemical analysis, including gas chro ... | 1966 | 5927037 |
| the adherence of lactic acid bacteria to the columnar epithelial cells of pigs and calves. | the adhesion of various lactobacilli and streptococci to columnar epithelial cells of pigs and calves were studied, by in vitro methods. the porcine strains isolated most frequently were lactobacillus delbrueckii, lact, acidophilus and lact. fermentum. thirteen of the 22 lactobacilli were adhesive. all the streptococci isolated belonged to lancefield's d-group; none of them adhered to pig epithelial cells. the adhesive strains (9 of 22) of calves were identified as lact. fermentum. adherence was ... | 1983 | 6654764 |
| influence of edta and its metal complexes on lactic acid fermentation. | a comparative study of the influence of edta and its metal complexes with fe, co, and ce on lactic acid fermentation by lactobacillus delbrueckii was done. it was observed that edta alone and its complex with ce could increase the yield of lactic acid up to 1--2%, while complexes of edta with fe and co enhanced the yield up to 4--5%. | 1980 | 6775435 |
| influence of mutagenic chemicals on fermentative production of lactic acid by lactobacillus delbrueckii. | the influence of ammonium fluoride, caffeine, alloxan, and hydrogen peroxide on the fermentative production of lactic acid by lactobacillus delbrueckii 9649 was studied. it has been found that hydrogen peroxide has an inhibitory effect, while caffeine and alloxan stimulate the fermentation process. the presence of ammonium fluoride does not have any marked influence on the fermentation process. | 1980 | 7424228 |
| fermentative production of lactic acid in presence of some trace elements. | an attempt was made to study the activity of lactobacillus delbrueckii under the influence of certain trace elements, viz. tl, u, th, and zr. from the results, it was inferred that tl has comparatively more stimulating effect on the acid-producing activity of the bacteria than u, th, and zr. | 1980 | 7456812 |
| a group i intron in the terminase gene of lactobacillus delbrueckii subsp. lactis phage ll-h. | an 837 nt long group ia intron was discovered in the lactobacillus delbrueckii subsp. lactis virulent phage ll-h genome. the ll-h intron conforms well to the secondary structure that is common to all group i introns. the only exception is that the extreme 3' nucleotide of the intron is an a residue instead of the usual g; despite this the intron is efficiently spliced in vivo. this ll-h intron contains an orf, orf168, which shows homology with endonucleases encoded by orfs contained in bacillus ... | 1995 | 7496530 |
| differentiation of lactobacillus strains by ribotyping. | fifty-four lactobacillus strains were differentiated by ribotyping. the stability of ribotypes characteristic of four strains of lactobacilli inhabiting the digestive tract of mice was investigated. one of four isolates of lactobacillus delbrueckii gt21, which had been associated with mice for 22 months, had an altered ribotype. | 1993 | 7504432 |
| ribosome binding site consensus sequence of lactobacillus delbrueckii subsp. lactis bacteriophage ll-h. | the putative ribosome binding sites preceding 32 of lactobacillus delbrueckii subsp. lactis bacteriophage ll-h genes were compared. a highly conserved consensus sequence for the ribosome binding sites of ll-h genes was inferred, gaaaggag. this study included the characterization of the last nucleotides of the 3'-end of the 16s rrna molecule from l. delbrueckii subsp. lactis and its comparison to the ribosome binding site consensus sequence. | 1994 | 7514146 |
| cloning and nucleotide sequence analysis of pepv, a carnosinase gene from lactobacillus delbrueckii subsp. lactis dsm 7290, and partial characterization of the enzyme. | cell extracts of lactobacillus delbrueckii subsp. lactis dsm 7290 were found to exhibit unique peptolytic ability against unusual beta-alanyl-dipeptides. in order to clone the gene encoding this activity, designated pepv, a gene library of strain dsm 7290 genomic dna, prepared in the low-copy-number plasmid plg339, was screened for heterologous expression in escherichia coli. recombinant clones harbouring pepv were identified by their ability to allow the utilization of carnosine (beta-alanyl-hi ... | 1994 | 7528082 |
| genetic analysis of acidocin b, a novel bacteriocin produced by lactobacillus acidophilus. | the genes encoding the production of acidocin b, a bacteriocin produced by lactobacillus acidophilus strain m46 which is active against listeria monocytogenes, clostridium sporogenes, brochothrix thermosphacta, lactobacillus fermentum and lactobacillus delbrueckii subsp. bulgaricus, but inactive against most other lactobacillus species, were previously localized on a 4 kb xbai-hindiii fragment of plasmid pcv461. in the present work, dna sequence analysis revealed the presence of three consecutiv ... | 1995 | 7551031 |
| a new mobile genetic element in lactobacillus delbrueckii subsp. bulgaricus. | a new is element (isl3) was discovered in lactobacillus delbrueckii subsp. bulgaricus during the characterization of the linkage relationships between the two genes important for milk fermentation, beta-galactosidase (lacz) and the cell-wall associated protease (prtp). isl3 is a 1494 bp element, flanked by 38 bp imperfect inverted repeats, and generates an 8 bp target duplication upon insertion. it contains one open reading frame, encoding a potential polypeptide of 434 amino acids, which shows ... | 1995 | 7565604 |
| enzymatic properties of lipase and characteristics production by lactobacillus delbrueckii subsp. bulgaricus. | some properties of an extracellular lipase produced by lactobacillus delbrueckii subsp. bulgaricus were studied. maximum enzyme activity was found against olive and butter oil as enzyme substrates. addition of 9% acacia gum, 0.1% na-deoxycholate and 0.01 m cacl2 to the enzyme reaction mixture increased-lipase activity from 5.3 to 14.5 (ffa/mg protein/minute) at ph 6.0 and at 40 degrees c. maximum lipase production was reached in the presence of glucose as a sole source of carbon, wheat bran as n ... | 1995 | 7574552 |
| [antimutagenic action of bacterial culture liquid on mutagenesis induced by 2-nitrofluorene in salmonella typhimurium strains]. | it was shown that cell extracts and cells of streptococcus faecalis decrease the mutagenic effect of 2-nitrofluorene in salmonella typhimurium strain ta1538 by 73 and 48%, respectively. cell extracts and cells of bifidobacterium bifidum and propionibacterium shermanii exhibited weak antimutagenic activity. no antimutagenic effect was found in escherichia coli ab1157, lactobacillus delbrueckii, or streptococcus thermophilus. antimutageneicity of the cell extract of str. faecalis is both associate ... | 1995 | 7590202 |
| [antimutagenic action of bacteria on mutagenesis induced by 4-nitroquinoline-1-oxide in salmonella typhimurium]. | it is shown that in the presence of culture liquid and cells of propionibacterium shermanii, p. pentosaceum, p. thoenii, p. coccoides, p. acnes, lactobacillus delbrueckii, streptococcus thermophilus, str. faecalis, bifidobacterium bifidum, and escherichia coli ab 1157 the mutagenicity of 4-nitroquinoline-1-oxide (4-nqo) in salmonella typhimurium ta 100 decreases significantly. the highest antimutagenic (desmutagenic) activity was found in culture liquid from all strains tested in the logarithmic ... | 1995 | 7616879 |
| influence of bile on beta-galactosidase activity of component species of yogurt starter cultures. | the influence of bile on beta-galactosidase activity and the cellular integrity of lactobacillus delbrueckii ssp. bulgaricus and streptococcus salivarius ssp. thermophilus were tested. two strains (os 1 and os 2) of l. delbrueckii ssp. bulgaricus and three strains (hc 15, 17, and 18) of s. salivarius ssp. thermophilus were studied. in the presence of .15% oxgall, beta-galactosidase activity of whole cells of both species was significantly increased. however, at a higher concentration (.3% oxgall ... | 1994 | 7699132 |
| d175 discriminates between nadh and nadph in the coenzyme binding site of lactobacillus delbrueckii subsp. bulgaricus d-lactate dehydrogenase. | the nad-dependent d-(-)-lactate dehydrogenase (d-ldh) from lactobacillus delbrueckii subsp. bulgaricus (in short, l. bulgaricus) has been modified at position 175 by site-directed mutagenesis, changing a conserved aspartate residue into an alanine. the d175a mutant enzyme displays a 40-fold shift in coenzyme preference from nadh to nadph. this demonstrates that d175 truly belongs to the amino acid consensus gxgxxgx(17)d (where x represents any residue) which is the signature of the coenzyme bind ... | 1995 | 7702618 |
| molecular cloning and dna sequence analysis of pepl, a leucyl aminopeptidase gene from lactobacillus delbrueckii subsp. lactis dsm7290. | a genomic library of lactobacillus delbrueckii subsp. lactis dsm7290 dna fragments from a sau3a partial digestion in the low-copy-number vector plg339, was used to screen escherichia coli for the presence of peptidases. using the chromogenic substrate leucine-beta-naphthylamide (leu-nh-nap) and e. coli strain cm89 lacking the corresponding enzyme activity in an enzymic plate assay, allowed the isolation of two peptidase genes; the newly described pepl and the recently cloned and sequenced pepn. ... | 1995 | 7737150 |
| shear stress effects on growth and activity of lactobacillus delbrueckii subsp. bulgaricus. | cells are frequently submitted to shear stresses during industrial processes. shear stress can be either beneficial or detrimental to the cells depending on the organism and on the level of intensity. the present work was designed to study the effect of shear stress on cell activity of a widely used lactic acid bacterium, lactobacillus delbrueckii subsp. bulgaricus (l. bulgaricus). a constant shear stress bioreactor, based on couette device, was developed and used to control shear stress from 0 ... | 1993 | 7763707 |
| cloning and dna sequence analysis of pepq, a prolidase gene from lactobacillus delbrueckii subsp. lactis dsm7290 and partial characterization of its product. | from a genomic library of lactobacillus delbrueckii subsp. lactis (dsm7290) dna, in the low-copy-number vector plg339, a recombinant clone was selected, which complemented a mutation in the prolidase gene (pepq) of escherichia coli uk173. nucleotide sequence analysis revealed an open reading frame of 1104 nucleotides corresponding to a protein of 368 amino acids with a calculated pi of 4.64 and a molecular mass of 41,087 da. the start site of pepq transcription was determined by primer extension ... | 1995 | 7770058 |
| factors involved in adherence of lactobacilli to human caco-2 cells. | a quantitative assay performed with bacterial cells labelled with [3h]thymidine was used to investigate factors involved in the adherence of human isolates lactobacillus acidophilus bg2fo4 and ncfm/n2 and lactobacillus gasseri adh to human caco-2 intestinal cells. for all three strains, adherence was concentration dependent, greater at acidic ph values, and significantly greater than adherence of a control dairy isolate, lactobacillus delbrueckii subsp. bulgaricus 1489. adherence of l. acidophil ... | 1994 | 7811085 |
| antimutagenicity of fermented milk. | reconstituted nonfat dry milk was fermented by lactobacillus helveticus ch65, lactobacillus acidophilus bg2fo4, streptococcus salivarius ssp. thermophilus ch3, lactobacillus delbrueckii ssp. bulgaricus 191r, and by a mixture of the latter two organisms. the fermented milks were then freeze-dried, extracted in acetone, dissolved in dimethylsulfoxide, and assayed for antimutagenicity in the ames test (salmonella typhimurium ta 100) against n-methyl, n'-nitro, n-nitroso-guanidine, and 3,2'-dimethyl ... | 1994 | 7814704 |
| characterization of the genome region encoding structural proteins of lactobacillus delbrueckii subsp. lactis bacteriophage ll-h. | two regions from the genome of the virulent lactobacillus delbrueckii subsp. lactic bacteriophage ll-h were sequenced (2330 and 12939 bp; 44% of the 34.6-kb genome). together with the previously sequenced region containing the major capsid protein-encoding gene (2498 bp), the sequence had 21 open reading frames (orfs) on the main coding strand. only two putative orfs were detected on the complementary strand. the orfs covered 93.2% of the sequence. all but four of the orfs were preceded by a rib ... | 1994 | 7828907 |
| characterization of genetic elements required for site-specific integration of lactobacillus delbrueckii subsp. bulgaricus bacteriophage mv4 and construction of an integration-proficient vector for lactobacillus plantarum. | temperate phage mv4 integrates its dna into the chromosome of lactobacillus delbrueckii subsp. bulgaricus strains via site-specific recombination. nucleotide sequencing of a 2.2-kb attp-containing phage fragment revealed the presence of four open reading frames. the larger open reading frame, close to the attp site, encoded a 427-amino-acid polypeptide with similarity in its c-terminal domain to site-specific recombinases of the integrase family. comparison of the sequences of attp, bacterial at ... | 1995 | 7836291 |
| cloning and nucleotide sequence analysis of the lactobacillus delbrueckii ssp. lactis dsm7290 cysteine aminopeptidase gene pepc. | a genomic library of lactobacillus delbrueckii ssp. lactis dsm7290 in the low copy number vector plg339, was screened for the presence of peptidase genes. using the chromogenic substrate gly-ala-beta-naphthylamide, which is not a substrate for any of the recently cloned peptidases of dsm7290, and the multiple peptidase deficient escherichia coli strain cm89, allowed the isolation of clones, which contained the equivalent hydrolytic activity. to identify genes encoding the conserved catalytic act ... | 1994 | 7851736 |
| cloning, molecular characterization, and expression of the genes encoding the lytic functions of lactococcal bacteriophage phi lc3: a dual lysis system of modular design. | the genes encoding the lysis proteins of lactococcus lactis bacteriophage phi lc3 were cloned, sequenced, and expressed in escherichia coli. the phi lc3 lysis genes, lysa and lysb, encode a membrane-disrupting protein (lysa) of 88 amino acids, and a cell wall degrading protein (lysb) of 429 amino acids, which shares significant sequence similarity with lysins from the streptococcus pneumoniae phages cp-1, cp-7, and cp-9, and lactobacillus delbrueckii phage mv1. both lysa and lysb function in e. ... | 1994 | 7922887 |
| nad(+)-dependent d-2-hydroxyisocaproate dehydrogenase of lactobacillus delbrueckii subsp. bulgaricus. gene cloning and enzyme characterization. | a genomic library from lactobacillus delbrueckii subsp. bulgaricus was used to complement an escherichia coli mutant strain deficient for both lactate dehydrogenase and pyruvate formate lyase, and thus unable to grow anaerobically. one recombinant clone was found to display a broad specificity nad(+)-dependent d-2-hydroxyacid dehydrogenase activity. the corresponding gene (named hdhd) was subcloned and sequenced. the deduced amino acid sequence of the encoded enzyme indicates a 333-residue prote ... | 1994 | 7925358 |
| determination and comparison of lactobacillus delbrueckii ssp. lactis dsm7290 promoter sequences. | the transcriptional start points of ten lactobacillus delbrückii ssp. lactis dsm7290 genes were determined by primer extension. the upstream located promoter regions, including potential -35 and -10 regions and the spacing between them were compared to the well-known escherichia coli and bacillus subtilis promoters. the lb. delbrückii -35 consensus sequence (ttgaca) seems to be less conserved then the e. coli sequence. the nucleotides tgc were often found upstream of the -10 region (tataat). the ... | 1994 | 7958762 |
| repeated sequences and the sites of genome rearrangements in bacteriophages of lactobacillus delbrueckii subsp. lactis. | we have sequenced the kis-element, a 1.5 kb insertion segment present in the genome of lactobacillus delbrueckii subsp. lactis phage ll-k, but absent from its close relative, phage ll-h. the kis-element showed some sequence features of a transposable element: it was flanked by direct repeats of a 20 nt long sequence which was in the genome of ll-h as a target sequence. the kis-element contained two putative orfs. the c-terminal part of orf333 consisted of clusters of direct repeats, capable of c ... | 1994 | 7979997 |
| identification and purification of a protein that induces production of the lactobacillus acidophilus bacteriocin lactacin b. | lactacin b is a heat-stable bacteriocin produced by lactobacillus acidophilus n2 that is active against closely related lactobacilli, including lactobacillus delbrueckii subsp. lactis (formerly lactobacillus leichmannii) atcc 4797. pure producer cultures propagated in mrs broth (initial ph 6.5) contain no lactacin b; it is detected only in cultures maintained at ph 5.0 to 6.0 and produced optimally at ph 6.0 s. f. barefoot and t. r. klaenhammer, antimicrob. agents chemother. 26:328-334, 1984). a ... | 1994 | 7986029 |
| cloning, sequencing and characterization of the pepip gene encoding a proline iminopeptidase from lactobacillus delbrueckii subsp. bulgaricus cnrz 397. | the proline iminopeptidase (pepip) of lactobacillus delbrueckii subsp. bulgaricus is a major peptidase located in the cell envelope. its structural gene (pepip) has been cloned into puc18 and expressed at a very high level in escherichia coli to give a pepip activity 15,000-fold higher than that found in l. delbrueckii subsp. bulgaricus. the nucleotide sequence of the pepip gene revealed an open reading frame of 295 codons encoding a protein with a predicted m(r) of 33,006, which is consistent w ... | 1994 | 8012575 |
| proline iminopeptidase from lactobacillus delbrueckii subsp. bulgaricus cnrz 397: purification and characterization. | proline iminopeptidase (pepip) is a major peptidase in lactobacillus delbrueckii subsp. bularicus cnrz397, encoded by the pepip gene. amplification and expression of this gene in escherichia coli k12 resulted in a very high level of enzyme production. moreover, export into the e. coli periplasm of 45% of pepip activity allowed us to purify the enzyme easily by a single ion-exchange chromatography step. pepip is a trimer of mr 100000 , composed of three identical subunits. in the presence of 0.1% ... | 1994 | 8012576 |
| cloning, heterologous expression, and sequencing of a novel proline iminopeptidase gene, pepi, from lactobacillus delbrueckii subsp. lactis dsm 7290. | the gene for proline iminopeptidase from lactobacillus delbrueckii subsp. lactis dsm 7290 coding for an enzyme that hydrolyses the synthetic substrate l-prolyl-beta-naphthylamide (pro-beta na) was cloned in escherichia coli. an enzymic plate assay was used to screen for positive clones. the gene, designated pepi, was subcloned into vector puc18 and sequenced. the nucleotide sequence revealed an 882 bp open reading frame encoding 294 amino acids, coding for an enzyme with a calculated molecular m ... | 1994 | 8025678 |
| antilisterial activity by enterococci in a model predicting the temperature evolution of taleggio, an italian soft cheese. | enterococcus ssp. produced broad-spectrum bacteriocins, which were active against listeria innocua and listeria monocytogenes. inhibition of l. innocua in milk by different starter cultures was evaluated. milk was inoculated with a conventional starter (streptococcus salivarius ssp. thermophilus and lactobacillus delbrueckii ssp. bulgaricus mixed cultures) as a sole starter or in combination with inhibitory starter cultures (enterococcus ssp., bacteriocin-producing strains). tests were performed ... | 1994 | 8046062 |
| biocompatibilities of organic solvents with lactobacillus delbrueckii. | in the search for biocompatible extractants for extractive fermentation of lactic acid, the effect of twelve organic solvents on the activity of l. delbrueckii were studied at different concentration levels. on this basis, the compatibilities of twelve solvents with l. delbrueckii were summarized into four classes: completely compatible, compatible at molecular level, partially compatible and non-compatible. the characteristics were described qualitatively for each class in terms of relative val ... | 1993 | 8061236 |
| antigenotoxic properties of lactic acid bacteria in the s. typhimurium mutagenicity assay. | a high percentage of human tumors is reported to be related to dietary habits. one way to improve the nutritional impact is to increase the intake of protective factors, such as inhibitors of dna damage and other types of anticarcinogens. specific strains of lactic acid bacteria used to ferment milk are promising candidates that may be antimutagenic and anticarcinogenic. we have studied the antimutagenicity of 10 isolated strains of beneficial lactic acid bacteria. four types of fermented milk p ... | 1993 | 8108275 |
| microbiological quality of french yogurts commercialized in spain. | the microbiological quality has been evaluated in 6 batches of yogurt (plain, flavoured and fruit-added) produced commercially in france and purchased in spain. the essential microflora: streptococcus salivarius subsp. thermophilus and lactobacillus delbrueckii subsp. bulgaricus, and contaminants (coliform bacteria, yeasts and molds) were checked. the ph was also measured. the totality of the samples tested fulfilled french and spanish regulation with respect to the presence of viable yogurt org ... | 1993 | 8128807 |
| kinetic studies of the action of lactacin f, a bacteriocin produced by lactobacillus johnsonii that forms poration complexes in the cytoplasmic membrane. | the bacteriocin lactacin f is bactericidal against lactobacillus delbrueckii, lactobacillus helveticus, and enterococcus faecalis. activity against l. delbrueckii was recently shown to be dependent on two peptides, lafa and lafx, which are encoded within the lactacin f operon (t. r. klaenhammer, fems microbiol. rev. 12:39-87, 1993). it has been proposed that two peptides form an active lactacin f complex. in this study, the action of lactacin f against e. faecalis atcc 19443 and the effects of v ... | 1994 | 8161167 |
| molecular analysis of the lactacin f operon. | lactacin f is a nonlantibiotic, heat-stable, peptide bacteriocin produced by lactobacillus johnsonii vpi11088. molecular analysis of the lactacin f dna region characterized a small operon that codes for three open reading frames, designated lafa, lafx, and orfz. the peptide encoded by lafa, the lactacin f structural gene, was compared with various peptide bacteriocins from lactic acid bacteria, and similarities were identified in the amino and carboxy termini of the propeptides. site-directed mu ... | 1993 | 8285694 |
| characterization of a prolate-headed bacteriophage of lactobacillus delbrueckii subsp. lactis, and its dna homology with isometric-headed phages. | a new lactobacillus delbrueckii subsp. lactis bacteriophage, jcl 1032, was characterized. jcl 1032 had a small, elongated prolate head, and a long non-contractile tail with cross-bars. the restriction map of jcl 1032 genome was constructed with five endonucleases. the genome was 45.8 kb in size, and it had cohesive ends (cos). molecular masses of the phage structural proteins were also determined. jcl 1032 showed dna homology with morphologically dissimilar, isometric-headed phages of lb. delbru ... | 1993 | 8379853 |
| antibiosis revisited: bacteriocins produced by dairy starter cultures. | well before the existence of starter bacteria was recognized, their activities were instrumental in preserving dairy foods. during growth in fermented products, dairy starters, including lactobacilli, lactococci, leuconostocs, streptococci, and propionibacteria, produce inhibitory metabolites. inhibitors include broad-spectrum antagonists, organic acids, diacetyl, and hydrogen peroxide. some starters also produce bacteriocins or bactericidal proteins active against species that usually are relat ... | 1993 | 8408870 |
| molecular comparison of the structural proteins encoding gene clusters of two related lactobacillus delbrueckii bacteriophages. | virulent phage ll-h and temperate phage mv4 are two related bacteriophages of lactobacillus delbrueckii. the gene clusters encoding structural proteins of these two phages have been sequenced and further analyzed. six open reading frames (orf-1 to orf-6) were detected. protein sequencing and western immunoblotting experiments confirmed that orf-3 (g34) encoded the main capsid protein gp34. the presence of a putative late promoter in front of the phage ll-h g34 gene was suggested by primer extens ... | 1993 | 8497043 |
| genetic and biochemical characterization of the lactobacillus delbrueckii subsp. lactis bacteriophage ll-h lysin. | ll-h, a virulent phage of lactobacillus delbrueckii subsp. lactis, produces a peptidoglycan-degrading enzyme, mur, that is effective on l. delbrueckii, lactobacillus acidophilus, lactobacillus helveticus, and pediococcus damnosus cell walls. in this study, the ll-h gene mur was cloned into escherichia coli, its nucleotide sequence was determined, and the enzyme produced in e. coli was purified and biochemically characterized. mur was purified 112-fold by means of ammonium sulfate precipitation a ... | 1995 | 8526515 |
| genome homology and superinfection immunity between temperate and virulent lactobacillus delbrueckii bacteriophages. | the presence of short homologous dna segments along the genomes of the temperate phage mv4 and the virulent phages ll-h, ll-k and jcl1032 of lactobacillus delbrueckii was demonstrated with southern hybridizations. one of these segments, the 2,817 nt mis element of phage mv4, was further characterized by nucleotide sequence analysis and by superinfection immunity studies. | 1995 | 8572946 |
| an x-prolyl dipeptidyl aminopeptidase (pepx) gene from lactobacillus helveticus. | the x-prolyl dipeptidyl aminopeptidase gene (pepx) of an industrially used lactobacillus helveticus strain has been detected by nucleic acid hybridization, cloned, characterized and sequenced. one orf of 2379 bp with coding capacity for a 90.6 kda protein (pepx) was found. the orf was preceded by a typical prokaryotic promoter region. an inverted repeat structure with delta g of -84.1 kj mol-1 was found downstream of the coding region. the deduced amino acid sequence of the 90.6 kda protein show ... | 1995 | 8574400 |
| rapid enzymatic method for biotyping and control of lactic acid bacteria used in the production of yogurt and some cheeses. | determination of enzymatic patterns of 30 strains of streptococcus thermophilus and 18 strains of lactobacillus delbrueckii subsp. bulgaricus with a rapid apizym method was carried out. alkaline and acid phosphatase, naphthol-as-bi-phosphohydrolase, 10 esterases, 20 glycosidases, 61 peptidases and 2 proteases (trypsin and chymotrypsin) were included. the strains investigated were isolated from yogurt and from different starters used for different italian cheeses. for s. thermophilus, all strains ... | 1995 | 8579994 |
| defective site-specific integration elements are present in the genome of virulent bacteriophage ll-h of lactobacillus delbrueckii. | the phage attachment site, attp, and the integrase-encoding gene, int, are sufficient to promote site-specific integration of the temperate phage mv4 genome into the chromosome of the lactobacillus delbrueckii host (l. dupont, b. boizet-bonhoure, m. coddeville, f. auvray, and p. ritzenthaler, j. bacteriol. 177:586--595, 1995). the mv4 genome region containing these elements was compared at the nucleotide and amino acid levels with that of the closely related virulent phage ll-h. complex dna rear ... | 1996 | 8633887 |
| a new cell surface proteinase: sequencing and analysis of the prtb gene from lactobacillus delbruekii subsp. bulgaricus. | investigation of the chromosomal region downstream of the lacz gene from lactobacillus delbrueckii subsp. bulgaricus revealed the presence of a gene (prtb) encoding a proteinase of 1,946 residues with a predicted molecular mass of 212 kda. the deduced amino acid sequence showed that prtb proteinase displays significant homology with the n termini and catalytic domains of lactococcal prtp cell surface proteinases and is probably synthesized as a preproprotein. however, the presence of a cysteine ... | 1996 | 8655480 |
| antimutagenicity of yogurt. | yogurt is milk fermented by a mixture of two bacteria: lactobacillus delbrueckii ssp. bulgaricus and streptococcus salivarius ssp. thermophilus. epidemiological studies have correlated a reduced risk of colon cancer with yogurt consumption. independent studies have established that yogurt and extracts thereof are antimutagenic. although multiple explanations can account for yogurt's putative anticarcinogenicity, we are interested in testing the hypothesis that antimutagenic compounds produced du ... | 1996 | 8657181 |
| observation of encapsulated lactic acid bacteria using confocal scanning laser microscopy. | the confocal scanning laser microscope allows direct observation of milk and cultured milks in their natural state. the microscope was used to observe the capsules of lactic acid bacteria growing in milk. capsule production was confirmed by microscopic observation of cells suspended in latex beads. some strains of streptococcus thermophilus were surrounded by a capsule 4 to 5 microns in diameter, and others by capsules 2 microns in diameter. lactobacillus delbrueckii ssp. bulgaricus strains show ... | 1995 | 8675749 |
| the potential of lactobacillus as a carrier for oral immunization: development and preliminary characterization of vector systems for targeted delivery of antigens. | oral administration of lactobacilli evokes mucosal and systemic immune responses against epitopes associated with these organisms (gerritse et al., 1990, 1991). the adjuvant function of different lactobacillus species was investigated under the conditions of intraperitoneal (i.p.) injection or oral administration. after i.p. injection of trinitrophenylated chicken gamma-globulin, high dth responses were observed with lactobacillus casei and lactobacillus plantarum, but low responses with lactoba ... | 1996 | 8717402 |
| the genes for phosphofructokinase and pyruvate kinase of lactobacillus delbrueckii subsp. bulgaricus constitute an operon. | in lactobacillus delbrueckii subsp. bulgaricus, the pyk gene coding for pyruvate kinase and the pfk gene coding for phosphofructokinase formed a bicistronic operon transcribed into a 2.9-kb rna. the nucleotide sequence of the pyk gene indicated that the encoded protein possessed an extra c-terminal domain with a potential phosphoenolpyruvate-dependent autophosphorylation site. | 1996 | 8755908 |
| the proteolytic system of lactobacillus sanfrancisco cb1: purification and characterization of a proteinase, a dipeptidase, and an aminopeptidase. | a cell envelope 57-kda proteinase, a cytoplasmic 65-kda dipeptidase, and a 75-kda aminopeptidase were purified from lactobacillus sanfrancisco cb1 sourdough lactic acid bacterium by sequential fast protein liquid chromatography steps. all of the enzymes are monomers. the proteinase was most active at ph 7.0 and 40 degrees c, while aminopeptidase and dipeptidase had optima at ph 7.5 and 30 to 35 degrees c. relatively high activities were observed at the ph and temperature of the sourdough ferment ... | 1996 | 8795211 |
| detection and localization of peptidases in lactococcus lactis with monoclonal antibodies. | monoclonal antibodies against peptidases of lactococcus lactis were isolated and characterized: pepn1-4 against a lysyl aminopeptidase pepn, pept1-5 against a tripeptidase pept and pepd1-3 against a dipeptidase pepd. these monoclonal antibodies reacted specifically with their respective antigens in crude cell extracts of lc. lactis subspp. cremoris and lactis. a number of monoclonal antibodies cross reacted with proteins of other (lactic acid) bacteria. pept1, 2, 4 and 5 cross reacted weakly wit ... | 1996 | 8861346 |
| genomic organization of lactic acid bacteria. | current knowledge of the genomes of the lactic acid bacteria, lactococcus lactis and streptococcus thermophilus, and members of the genera lactobacillus, leuconostoc, pediococcus and carnobacterium, is reviewed. the genomes contain a chromosome within the size range of 1.8 to 3.4 mbp. plasmids are common in lactococcus lactis (most strains carry 4-7 different plasmids), some of the lactobacilli and pediococci, but they are not frequently present in s. thermophilus, lactobacillus delbrueckii subs ... | 1996 | 8879406 |
| influence of medium composition on lactic acid production from dried whey by lactobacillus delbrueckii. | the production of lactic acid, lactic acid dehydrogenase (ldh) and single cell protein (scp) from dried whey by fermentation with lactobacillus delbrueckii subsp, bulgaricus 369 was investigated. a medium consisting of dried whey and supplements which enabled exponential growth of the organism was developed. maximum lactic acid production was achieved using enriched whey (8% w/v), at ph 5.5 for 24 h. addition of yeast extract plus mncl2 gave the highest production of lactic acid (1.71 g/l.h), sp ... | 1996 | 8897421 |
| evaluation of media for selective enumeration of streptococcus thermophilus, lactobacillus delbrueckii ssp. bulgaricus, lactobacillus acidophilus, and bifidobacteria. | fifteen media were evaluated to determine their suitability for selective enumeration of streptococcus thermophilus, lactobacillus delbrueckii ssp. bulgaricus, lactobacillus acidophilus, and bifidobacteria using 5 to 6 strains of each of the four groups of organisms. streptococcus thermophilus agar was found to be suitable for selective enumeration of s. thermophilus under aerobic incubation at 37 degrees c for 24 h. the mrs agar at ph 5.2 or reinforced clostridial agar at ph 5.3 could be used f ... | 1996 | 8899517 |
| the early gene region completes the nucleotide sequence of lactobacillus delbrueckii subsp. lactis phage ll-h. | transcription of genes from phage ll-h can be divided into an early phase and a late phase. the early gene region was located in a 5.9-kb segment of the phage ll-h genome and it was part of the sequence that completed the phage ll-h genome sequence, 34 659 bp in size. phage ll-h is the first completely sequenced lactobacillus phage. in the main coding strand of phage ll-h genome 48 putative orfs could be detected, but only four small putative orfs could be found in the opposite strand. the orfs ... | 1996 | 8917075 |
| characterization of pepr1, a gene coding for a potential transcriptional regulator of lactobacillus delbrueckii subsp. lactis dsm7290. | the gene designated pepr1, encoding a potential transcription regulator of lactobacillus delbrueckii subsp. lactis dsm7290, was identified by sequence similarity of an open reading frame located upstream of the prolidase pepq orientated in opposite direction. pepq and pepr1 coding regions are spaced by 152 nucleotides. upstream of the -35 region of pepq, a 14-bp palindromic sequence, homologous to the catabolite responsive element, could be identified. the peprl gene has the potential to encode ... | 1996 | 8919457 |
| characterization of lactobacilli by southern-type hybridization with a lactobacillus plantarum pyrdfe probe. | lactobacillus plantarum, lactobacillus pentosus, and lactobacillus paraplantarum (m.-c. curk, j.-c. hubert, and f. bringel, int. j. syst. bacteriol. 46:595-598, 1996) can hardly be distinguished on the basis of their phenotypes. unlike l. plantarum and l. paraplantarum, l. pentosus ferments glycerol and xylose but not melezitose. we identified two l. pentosus strains (cnrz 1538 and cnrz 1544) which ferment glycerol and melezitose but not xylose. alpha-methyl-d-mannoside was fermented by 66% of t ... | 1996 | 8934911 |
| the effect of cations on the hydrolysis of lactose and the transferase reactions catalysed by beta-galactosidase from six strains of lactic acid bacteria. | beta-galactosidases from lactobacillus delbruekii subsp. bulgaricus 20056, lb. casei 20094, lactococcus lactis subsp. lactis 7962, streptococcus thermophilus ts2, pediococcus pentosaceus pe39 and bifidobacterium bifidum 1901 were partially purified. the rate of hydrolysis of lactose given by the predominant beta-galactosidase activity from each of the bacteria studied was in all cases enhanced by mg2+, while the effect of k+ and na+ differed from strain to strain. the beta-galactosidases from al ... | 1996 | 8987531 |
| an operon from lactobacillus helveticus composed of a proline iminopeptidase gene (pepi) and two genes coding for putative members of the abc transporter family of proteins. | a proline iminopeptidase gene (pepi) of an industrial lactobacillus helveticus strain was cloned and found to be organized in an operon-like structure of three open reading frames (orf1, orf2 and orf3). orf1 was preceded by a typical prokaryotic promoter region, and a putative transcription terminator was found downstream of orf3, identified as the pepi gene. using primer-extension analyses, only one transcription start site, upstream of orf1, was identifiable in the predicted operon. although t ... | 1996 | 9004508 |
| production, purification and characterization of reutericin 6, a bacteriocin with lytic activity produced by lactobacillus reuteri la6. | a bacteriocin (reutericin 6) produced by lactobacillus reuteri la6, was purified by hydrophobic chromatography from the modified mrs broth (d'-mrs) with 6180-fold increase in specific activity with 14% recovery. the molecular weight of reutericin 6 was determined to be 2.7 kda by sds-page and esi-ms. by amino acid analysis, reutericin 6 comprised of 67% hydrophobic and polar neutral amino acids. lanthionine was not detected. the lytic activity against lactobacillus delbrueckii subsp. bulgaricus ... | 1997 | 9039561 |
| lactobacillus delbrueckii subsp. lactis dsm7290 pepg gene encodes a novel cysteine aminopeptidase. | a number of escherichia coli clones were isolated from a lactobacillus delbrueckii subsp. lactis gene library capable of hydrolysing the chromogenic substrate gly-ala-beta-naphthylamide (gly-ala-beta na). some of the recombinant plasmids carried by these clones have been shown to encode the cysteine aminopeptidase gene pepc. nucleotide sequence analyses of the plasmid inserts of the remaining clones resulted in the identification of two adjacent orfs encoding proteins exhibiting a high degree of ... | 1997 | 9043129 |
| d-2-hydroxy-4-methylvalerate dehydrogenase from lactobacillus delbrueckii subsp. bulgaricus. i. kinetic mechanism and ph dependence of kinetic parameters, coenzyme binding and substrate inhibition. | the steady-state kinetics of d-2-hydroxy-4-methylvalerate dehydrogenase have been studied at ph 8.0 by initial velocity, product inhibition, and dead-end inhibition techniques. the mechanism is rapid-equilibrium ordered in the nad+ plus d-2-hydroxy-4-methylvalerate direction, and steady-state ordered in the other direction. in both cases coenzyme is the first substrate added and both the e-nadh-d-2-hydroxy-4-methylvalerate and e-nad+-2-oxo-4-methylvalerate give rise to abortive complexes which c ... | 1997 | 9063465 |
| d-2-hydroxy-4-methylvalerate dehydrogenase from lactobacillus delbrueckii subsp. bulgaricus. ii. mutagenic analysis of catalytically important residues. | five residues involved in catalysis and coenzyme binding have been identified in d-2-hydroxy-4-methylvalerate dehydrogenase from lactobacillus delbrueckii subsp. bulgaricus by using biochemical and genetical methods. enzyme inactivation with diethylpyrocarbonate indicated that a single histidine residue was involved in catalysis. since h296 is the only conserved histidine in the whole family of nad-dependent d-2-hydroxyacid dehydrogenases, we constructed the h296q and h296s mutants and showed th ... | 1997 | 9063466 |
| plasmid integration in a wide range of bacteria mediated by the integrase of lactobacillus delbrueckii bacteriophage mv4. | bacteriophage mv4 is a temperate phage infecting lactobacillus delbrueckii subsp. bulgaricus. during lysogenization, the phage integrates its genome into the host chromosome at the 3' end of a trna(ser) gene through a site-specific recombination process (l. dupont et al., j. bacteriol., 177:586-595, 1995). a nonreplicative vector (pmc1) based on the mv4 integrative elements (attp site and integrase-coding int gene) is able to integrate into the chromosome of a wide range of bacterial hosts, incl ... | 1997 | 9068626 |
| a zinc-dependent proteinase from the cell wall of lactobacillus delbrueckii subsp. bulgaricus. | a zinc-dependent proteinase was extracted from the cell wall of lactobacillus delbrueckii subsp. bulgaricus and partially purified despite a marked unstability. the caseinolytic activity was associated with a polypeptide chain of 65 kda that belonged to the m1 family of zinc-dependent proteases. this zinc-dependent proteinase could degrade intact caseins, with a significant preference for beta-casein. the ph-profile of its activity indicated that its relative contribution to the caseinolytic act ... | 1997 | 9080696 |
| development of oligonucleotide primers from the 16s-23s rrna intergenic sequences for identifying different dairy and probiotic lactic acid bacteria by pcr. | spacer regions between the 16s and 23s rrna genes of different dairy and probiotic lactic acid bacteria were amplified by the polymerase chain reaction (pcr) with conserved primers and the nucleotide sequences of these spacer regions were determined. amplification/oligonucleotide primer pairs were designed for lactobacillus paracasei, lactobacillus rhamnosus, lactobacillus delbrueckii, lactobacillus acidophilus, lactobacillus helveticus and streptococcus thermophilus based on the differences in ... | 1997 | 9081225 |
| characterization of a thiol-dependent endopeptidase from lactobacillus helveticus cnrz32. | an endopeptidase gene (pepe) was isolated from a previously constructed genomic library of lactobacillus helveticus cnrz32. the pepe gene consisted of a 1,314-bp open reading frame encoding a putative peptide of 52.1 kda. significant identity was found between the deduced amino acid sequence of pepe and the sequences for aminopeptidase c from lactobacillus delbrueckii subsp. lactis dsm7290, l. helveticus cnrz32, streptococcus thermophilus cnrz302, and lactococcus lactis subsp. cremoris am2. a re ... | 1997 | 9098049 |
| characteristics and genetic determinants of bacteriocin activities produced by carnobacterium piscicola cp5 isolated from cheese. | carnobacterium piscicola cp5, isolated from a french mold-ripened soft cheese, produced a bacteriocin activity named carnocin cp5, which inhibited carnobacterium, enterococcus and listeria spp. strains, and among the lactobacillus spp. only lactobacillus delbrueckii spp. [24]. the activity was purified by ammonium sulfate precipitation, anion exchange, and hydrophobic interaction chromatography followed by reverse-phase high-performance liquid chromatography (rp-hplc). this latter step separated ... | 1997 | 9353214 |
| a continuous coupled spectrophotometric assay for tyrosine aminotransferase activity with aromatic and other nonpolar amino acids. | a continuous assay for escherichia coli tyrosine aminotransferase (tatase) that employs lactobacillus delbrueckii ssp. bulgaricus hydroxyisocaproate dehydrogenase (ho-hxodh) as a coupling enzyme is described. alpha-keto acids, including those formed by tatase-catalyzed transamination of l-phenylalanine, l-tyrosine, l-tryptophan, l-methionine, and l-leucine, are converted to the corresponding alpha-hydroxy acids by the auxiliary enzyme. the concomitant reduction of nadh by this enzyme can be foll ... | 1997 | 9356140 |
| inhibition of salmonella typhimurium attachment to chicken cecal mucus by intestinal isolates of enterobacteriaceae and lactobacilli. | the ability of selected strains of enterobacteriaceae or lactobacilli isolated from the intestines of adult chickens to inhibit in vitro attachment of salmonella typhimurium 3333/o to cecal mucus in the presence or absence of d-mannose was determined. attachment in the absence of mannose was reduced by prior exposure of mucus to cultures of two isolates of enterobacteriaceae, an escherichia coli and a hafnia alvei strain, but not to a third isolate, an enterobacter agglomerans strain. attachment ... | 1997 | 9356699 |
| properties of porcine and yogurt lactobacilli in relation to lactose intolerance. | lactobacilli that had been isolated from the stomach of piglets were tested for properties relevant to the production of fermented milk products for consumption by lactose-intolerant humans. the strains were characterized for beta-galactosidase activity, the ability to reduce the lactose concentration of milk, viability, and ph of the fermented milk over a 30-d period. strains that had favorable attributes were studied further, and the optimal ph for beta-galactosidase activity, ability to grow ... | 1997 | 9361203 |
| application of the extracellular alpha-amylase gene from streptococcus bovis 148 to construction of a secretion vector for yogurt starter strains. | streptococcus thermophilus atcc 19258, lactobacillus delbrueckii subsp. bulgaricus t-11, and lactococcus lactis subsp. lactis il1403 were transformed with the alpha-amylase gene (amya) from streptococcus bovis 148 by using a wide host-range vector, and all the transformants secreted the alpha-amylase successfully. since the promoter and the secretion signal of the amya gene were functional in these strains, we constructed a secretion vector using the expression elements of amya. trials to secret ... | 1997 | 9361445 |
| fecal microflora in a patient with short-bowel syndrome and identification of dominant lactobacilli. | fecal microflora and lactate concentrations in blood and feces obtained from a patient (a 5 year-old boy) with short-bowel syndrome (sbs) were compared during acidosis to results for the normal condition (no sbs symptoms). the taxonomical position of the lactobacilli found predominantly in the feces sample obtained 2 days before the fifth attack was also studied. the d-lactate level in serum obtained 1 day after the fourth attack was 10-fold higher than that for the normal condition, although th ... | 1997 | 9399516 |
| influence of yogurt and acidophilus yogurt on serum cholesterol levels in mice. | the effects of yogurt and acidophilus yogurt on the weight gain, serum cholesterol, high density lipoprotein cholesterol, low density lipoprotein cholesterol, triglycerides, and the numbers of fecal lactobacilli and coliforms were investigated in mice assigned to three dietary treatments for 56 d: 1) commercial rodent chow and water (control), 2) commercial rodent chow and yogurt made from milk inoculated with a 3% (vol/vol) liquid culture of streptococcus thermophilus and lactobacillus delbruec ... | 1997 | 9406066 |
| lactobacilli carry cryptic genes encoding peptidase-related proteins: characterization of a prolidase gene (pepq) and a related cryptic gene (orfz) from lactobacillus delbrueckii subsp. bulgaricus. | two genes, pepq and orfz, encoding a prolidase and a prolidase-like protein, respectively, were cloned and characterized from lactobacillus delbrueckii subsp. bulgaricus. the identity of the pepq and orfz genes with the lactobacillus delbrueckii subsp. lactis prolidase gene (pepq) was shown to be 98% and 60%, respectively. both pepq and orfz were preceded by a putative promoter region. northern analysis of pepq mrna revealed a 1.1 kb transcript indicating that pepq forms a monocistronic transcri ... | 1997 | 9421914 |
| manufacture and quality of iron-fortified yogurt. | yogurts (nonfat and low fat) were manufactured and fortified with 10, 20, and 40 mg of iron/kg of yogurt. growth of starter culture bacteria and nonstarter culture bacteria as well as lipid oxidation of the yogurts were monitored over 30 d of storage at 4 degrees c. sensory characteristics of the yogurts were determined during that time by a trained panel of judges, and consumer panels were used to test acceptability of iron-fortified yogurt. counts of lactobacillus delbrueckii ssp. bulgaricas a ... | 1997 | 9436092 |
| optimization of exopolysaccharide production by lactobacillus delbrueckii subsp. bulgaricus rr grown in a semidefined medium. | the optimal fermentation temperature, ph, and bacto-casitone (difco laboratories, detroit, mich.) concentration for production of exopolysaccharide by lactobacillus delbrueckii subsp. bulgaricus rr in a semidefined medium were determined by using response surface methods. the design consisted of 20 experiments, 15 unique combinations, and five replications. all fermentations were conducted in a fermentor with a 2.5-liter working volume and were terminated when 90% of the glucose in the medium ha ... | 1998 | 9464404 |
| evolution of streptococcus thermophilus bacteriophage genomes by modular exchanges followed by point mutations and small deletions and insertions. | comparative sequence analysis of 40% of the genomes from two prototype streptococcus thermophilus bacteriophages (lytic group i phage phi sfi19 and the cos site containing temperate phage phi sfi21) suggested two processes in the evolution of their genomes. in a first evolutionarily distant phase the basic genome structure was apparently constituted by modular exchanges. over the 17-kb-long dna segment analyzed in the present report, we observed clusters of genes with similarity to genes from le ... | 1998 | 9499809 |
| permeabilization of streptococcus thermophilus and lactobacillus delbrueckii subsp. bulgaricus with ethanol. | streptococcus thermophilus and lactobacillus delbrueckii subsp. bulgaricus cultures were treated with ethanol and tested for viability and beta-galactosidase activity. exposure of the biomass of test cultures to 30%-55% ethanol (vol/vol) caused a 100% loss of viability and up to 15-fold increase in measurable beta-galactosidase activity in both streptococci and lactobacilli. ethanol-treated cell suspensions could be stored for up to 6 months without loss of enzyme activity. the nonviable permeab ... | 1998 | 9504985 |
| effects of lactic acid bacteria on binding and absorption of mutagenic heterocyclic amines. | effects of binding heterocyclic amines to cells of lactic acid bacteria on theirs absorption were investigated. cells of lactobacillus delbrueckii subsp. bulgaricus 2038 and streptococcus thermophilus 1131 bind both 3-amino-1,4-dimethyl-5h-pyrido[4,3-b]indole (trp-p-1) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (meiqx). the binding of strain 1131 cells to trp-p-1 was maximum in the phs from 4 to 8, but strain 2038 cells bound trp-p-1 and meiqx only slightly at ph 7. we investigated the ab ... | 1998 | 9532774 |