| expression of a chitinase gene from serratia marcescens in lactococcus lactis and lactobacillus plantarum. | a chitinase gene from the gram-negative bacterium serratia marcescens bjl200 was cloned in lactococcus lactis subsp. lactis mg1363 and in the silage inoculum strain lactobacillus plantarum e19b. the chitinase gene was expressed as an active enzyme at a low level in lactococcus lactis, when cloned in the same transcriptional orientation as the gene specifying the replication protein of the vector pil253. using the expression vectors pmg36e and pgkv259 with lactococcal promoter fragments p32 and p ... | 1994 | 7765812 |
| segregational stability and copy number of the theta-type lactococcal replicon rep22 in lactococcus. | rep22 is the replication region of the lactococcal theta replicating pucl22 plasmid. the copy number of rep22-based plasmids in lactococcus was determined by using a chromosomal dna fragment from lactococcus lactis subsp. lactis mms368 as reference. segregational behavior appeared to be linked to copy number and therefore indicated random distribution of copies to daughter cells. nevertheless, an active partitioning system was detected in the parental plasmid pucl22. a pucl22 138-bp dna restrict ... | 1995 | 7765880 |
| identification and molecular analysis of lactococcus lactis rpod operon. | the complete nucleotide sequence of an open reading frame (orf) preceding the lactococcus lactis rpod gene is reported. it was suggested that this orf encodes lactococcus lactis dna primase and that the l. lactis rpod operon consists of only two genes. northern hybridization analysis showed that i) there are four mrnas transcribing the rpod gene (from upstream, m1-m4), ii) only the 3.7-kb transcript m1 includes the entire rpod operon, iii) the shortest transcript m4 exists at both logarithmic an ... | 1995 | 7765979 |
| the lysins of bacteriophages infecting lactic acid bacteria. | this short review highlights the complete absence of literature on lysins of bacteriophages infecting species like s. salivarius subsp. thermophilus, pediococcus and leuconostoc species, l. helveticus, l. acidophilus, l. plantarum and l. brevis, which are also widely used in the dairy industry. the lysins described share some similar biochemical characteristics: optimal ph and temperature, site of hydrolysis inside the peptidoglycan, and some activators and inhibitors. the cloning of the genes e ... | 1995 | 7766123 |
| medium-dependent regulation of proteinase gene expression in lactococcus lactis: control of transcription initiation by specific dipeptides. | transcriptional gene fusions with the escherichia coli beta-glucuronidase gene (gusa) were used to study the medium- and growth-dependent expression of the divergently transcribed genes involved in proteinase production (prtp and prtm) of lactococcus lactis sk11. the results show that both the prtp and prtm genes are controlled at the transcriptional level by the peptide content of the medium and, to a lesser extent, by the growth rate. a more than 10-fold regulation in beta-glucuronidase activi ... | 1995 | 7768792 |
| the extracellular pi-type proteinase of lactococcus lactis hydrolyzes beta-casein into more than one hundred different oligopeptides. | the peptides released from beta-casein by the action of pi-type proteinase (prtp) from lactococcus lactis subsp. cremoris wg2 have been identified by on-line coupling of liquid chromatography to mass spectrometry. after 24 h of incubation of beta-casein with purified prtp, a stable mixture of peptides was obtained. the trifluoroacetic acid-soluble peptides of this beta-casein hydrolysate were fractionated by high-performance liquid chromatography and introduced into the liquid chromatography-ion ... | 1995 | 7768856 |
| lactococcus lactis glyceraldehyde-3-phosphate dehydrogenase gene, gap: further evidence for strongly biased codon usage in glycolytic pathway genes. | the gene gap, encoding glyceraldehyde-3-phosphate dehydrogenase (ec 1.2.1.12), was isolated from a genomic library of lactococcus lactis lm0230 dna. plasmids containing the l. lactis gene were able to complement a gap mutant of escherichia coli. the nucleotide sequence of gap predicted a polypeptide chain of 337 amino acids for the enzyme and a subunit molecular mass of 36,043. the codon usage in gap and four other glycolytic genes from l. lactis showed a high degree of bias, when compared with ... | 1995 | 7773380 |
| genes involved in immunity to the lantibiotic nisin produced by lactococcus lactis 6f3. | the lantibiotic nisin is produced by several strains of lactococcus lactis. the complete gene cluster for nisin biosynthesis in l. lactis 6f3 comprises 15 kb of dna. as described previously, the structural gene nisa is followed by the genes nisb, nist, nisc, nisi, nisp, nisr, and nisk. further analysis revealed three additional open reading frames, nisf, nise, and nisg, adjacent to nisk. approximately 1 kb downstream of the nisg gene, three open reading frames in the opposite orientation have be ... | 1995 | 7793910 |
| cloning and sequencing of lladchi [corrected] restriction/modification genes from lactococcus lactis and relatedness of this system to the streptococcus pneumoniae dpnii system. | the natural 7.8-kb plasmid psrq700 was isolated from lactococcus lactis subsp. cremoris dch-4. it encodes a restriction/modification system named lladchi [corrected]. when introduced into a phage-sensitive l. lactis strain, psrq700 confers strong phage resistance against the three most common lactococcal phage species, namely, 936, c2, and p335. the lladchi [corrected] endonuclease was purified and found to cleave the palindromic sequence 5'-gatc-3'. it is an isoschizomer of streptococcus pneumo ... | 1995 | 7793939 |
| biochemical and genetic characterization of pepf, an oligopeptidase from lactococcus lactis. | lactococcus lactis possesses a complex proteolytic system which is essential for its growth in milk. we characterized one of the peptidases of this system, oligopeptidase pepf, together with its structural gene. pepf hydrolyzed peptides containing between 7 and 17 amino acids with a rather wide specificity. it was purified to homogeneity. the n-terminal sequences of pepf and of peptides resulting from tryptic digestion of pepf were determined and used to design degenerate oligonucleotides which ... | 1994 | 7798200 |
| genetic analysis of regions of the lactococcus lactis subsp. lactis plasmid prs01 involved in conjugative transfer. | the genes responsible for conjugative transfer of the 48.4-kb lactococcus lactis subsp. lactis ml3 plasmid prs01 were localized by insertional mutagenesis. integration of the is946-containing plasmid ptrk28 into prs01 generated a pool of stable cointegrates, including a number of plasmids altered in conjugative proficiency. mapping of ptrk28 insertions and phenotypic analysis of cointegrate plasmids identified four distinct regions (tra1, tra2, tra3, and tra4) involved in prs01 conjugative trans ... | 1994 | 7811081 |
| growth of enterococcus, lactococcus and streptococcus strains and environmental isolates in liquid media and their reactions on beea. | growth of known species of enterococcus, lactococcus and streptococcus and aerococcus viridans in selective and nonselective liquid media routinely used to enumerate faecal streptococci was measured optically at different temperatures. growth of environmental isolates was measured in some of these media. growth of the reference strains on bile esculin azide agar at elevated incubation temperatures was tested. the results revealed only minor differences between media but strong influence of incub ... | 1994 | 7811573 |
| mosaic structure of large regions of the lactococcus lactis subsp. cremoris chromosome. | lactococcus lactis subsp. lactis and lactococcus lactis subsp. cremoris are closely related phenotypically and genetically. here we report that certain regions of their chromosomes diverge considerably more than others. conserved regions differ by less than 20%, whilst variable regions differ by more than 60%. this mosaic structure may have arisen by horizontal gene transfer from distantly related bacteria since in a particular region of the l. lactis subsp. cremoris chromosome the g+c content a ... | 1994 | 7812446 |
| sequence and organization of the lactococcal prolate-headed bil67 phage genome. | bil67 is a broad-host-range prolate-headed phage that is active against lactococcus cells. the complete phage genome sequence of 22195 bp was established. thirty-seven open reading frames (orfs) organized in two clusters were identified. functions were assigned to the putative products of six of the orfs on the basis of comparison of the deduced amino acid sequences to known proteins, analysis of structural features of the proteins and search for conserved motifs. these were a dna polymerase, a ... | 1994 | 7812447 |
| two lactococcus lactis genes, including lacx, cooperate to trigger an sos response in a reca-negative background. | a 4.3-kb ecori fragment from a lactococcus lactis genomic library alleviates the methyl methanesulfonate, mitomycin c, and uv sensitivities of an escherichia coli reca mutant (m. novel, x. f. huang, and g. novel, fems microbiol. lett. 72:309-314, 1990). it complements reca1 and delta reca mutations but not reca13. three proteins (with molecular masses of 20, 35, and 23 kda) were produced from this fragment in a t7-directed system, and three corresponding genes were detected by dna sequencing, na ... | 1995 | 7814316 |
| absence of cholic acid 7 alpha-dehydroxylase activity in the strains of lactobacillus and bifidobacterium. | to investigate the presence of 7 alpha-dehydroxylase activity on bile acids in the bacterial strains of fermented milk products, 46 strains of lactobacillus casei, lactobacillus paracasei, lactobacillus rhamnosus, lactobacillus acidophilus, lactobacillus gasseri, bifidobacterium adolescentis, bifidobacterium bifidum, bifidobacterium breve, bifidobacterium infantis, bifidobacterium longum, lactococcus lactis spp. lactis, and streptococcus salivarius spp. thermophilus were tested for their ability ... | 1994 | 7814703 |
| the pot family of transport proteins. | | 1994 | 7817396 |
| genetic aspects of aromatic amino acid biosynthesis in lactococcus lactis. | polymerase chain reaction (pcr) primers designed from a multiple alignment of predicted amino acid sequences from bacterial aroa genes were used to amplify a fragment of lactococcus lactis dna. an 8 kb fragment was then cloned from a lambda library and the dna sequence of a 4.4 kb region determined. this region was found to contain the genes tyra, aroa, arok, and phea, which are involved in aromatic amino acid biosynthesis and folate metabolism. tyra has been shown to be secreted and arok also h ... | 1995 | 7823907 |
| transport of beta-casein-derived peptides by the oligopeptide transport system is a crucial step in the proteolytic pathway of lactococcus lactis. | in the proteolytic pathway of lactococcus lactis, milk proteins (caseins) are hydrolyzed extracellularly to oligopeptides by the proteinase (prtp). the fate of these peptides, i.e. extracellular hydrolysis followed by amino acid uptake or transport followed by intracellular hydrolysis, has been addressed. mutants have been constructed that lack a functional di-tripeptide transport system (dtpt) and/or oligopeptide transport system (opp) but do express the p1-type proteinase (specific for hydroly ... | 1995 | 7829486 |
| primary structure and functional analysis of the lysis genes of lactobacillus gasseri bacteriophage phi adh. | the lysis genes of the lactobacillus gasseri bacteriophage phi adh were isolated by complementation of a lambda sam mutation in escherichia coli. nucleotide sequencing of a 1,735-bp dna fragment revealed two adjacent coding regions of 342 bp (hol) and 951 bp (lys) in the same reading frame which appear to belong to a common transcriptional unit. proteins corresponding to the predicted gene products, holin (12.9 kda) and lysin (34.7 kda), were identified by in vitro and in vivo expression of the ... | 1995 | 7836307 |
| purification and characterization of a general aminopeptidase (st-pepn) from streptococcus salivarius ssp. thermophilus cnrz 302. | a general aminopeptidase (st-pepn) was purified from an intracellular extract of streptococcus salivarius ssp. thermophilus cnrz 302 by ion-exchange chromatography and hydrophobic interaction chromatography. gel electrophoresis of the purified enzyme in denaturing or nondenaturating conditions showed a single protein band. the enzyme is a monomer with a molecular mass of 97 kda. its activity is maximal at ph 7 and 36 degrees c and is completely abolished by cucl2 and zncl2. the enzyme is strongl ... | 1994 | 7836577 |
| [the dental pulp reaction to microbial action in different methods of treating the carious cavity]. | under study were the effects of bacterial stimulation of prepared dentin on dental pulp. traditional method of drug treatment of prepared cavity with alcohol and either was compared with methods reducing dentin permeability making use of calcium hydroxide, potassium nitrate, and calcium oxalate. inflammatory reaction of the pulp was more pronounced after traditional treatment. reduction of dentin permeability with agents blocking dentin tubes reduced the severity of inflammatory reaction. | 1994 | 7846716 |
| 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 |
| functional expression in saccharomyces cerevisiae of the lactococcus lactis mles gene encoding the malolactic enzyme. | malolactic fermentation, a crucial step in winemaking, results mostly in degradation by lactic acid bacteria of l-malic acid into l-lactic acid. this direct decarboxylation is catalysed by the malolactic enzyme. recently we, and others, have cloned the mles gene of lactococcus lactis encoding malolactic enzyme. heterologous expression of mles in saccharomyces cerevisiae was tested to perform simultaneously alcoholic and malolactic fermentations by yeast. mles gene was cloned in a yeast multicopy ... | 1995 | 7867919 |
| an aminopeptidase p from lactococcus lactis with original specificity. | an aminopeptidase p (e.c. 3.4.11.9) that cleaves the arg-1-pro-2 bond of bradykinin has been isolated for the first time from lactococcus lactis. the peptidase was purified to homogeneity in a 3-step procedure and characterized. it is a monomeric metalloenzyme with a 43 kda molecular mass, activated by mn2+ and inhibited by dtt. it differs from the majority of aminopeptidases p already described by displaying a specificity for x-pro-pro n-terminal and probably an extended binding site that could ... | 1995 | 7873564 |
| regulation of 2-deoxyglucose phosphate accumulation in lactococcus lactis vesicles by metabolite-activated, atp-dependent phosphorylation of serine-46 in hpr of the phosphotransferase system. | lactococcus lactis takes up glucose and the nonmetabolizable glucose analogue 2-deoxyglucose (2dg) via the phosphotransferase system and extrudes the accumulated sugar phosphates in a process apparently dependent on a cytoplasmic sugar-phosphate phosphatase. uptake of 2dg into l. lactis vesicles was shown to be dependent on an energy source, effectively provided by intravesicular phosphoenolpyruvate (pep). 2dg phosphate (2dg-p) accumulation in these vesicles was not inhibited, and preaccumulated ... | 1994 | 7881559 |
| molecular cloning and nucleotide sequence of the gene encoding the major peptidoglycan hydrolase of lactococcus lactis, a muramidase needed for cell separation. | a gene of lactococcus lactis subsp. cremoris mg1363 encoding a peptidoglycan hydrolase was identified in a genomic library of the strain in puc19 by screening escherichia coli transformants for cell wall lysis activity on a medium containing autoclaved, lyophilized micrococcus lysodeikticus cells. in cell extracts of l. lactis mg1363 and several halo-producing e. coli transformants, lytic bands of similar sizes were identified by denaturing sodium dodecyl sulfate (sds)-polyacrylamide gels contai ... | 1995 | 7883712 |
| a di- and tripeptide transport system can supply listeria monocytogenes scott a with amino acids essential for growth. | listeria monocytogenes takes up di- and tripeptides via a proton motive force-dependent carrier protein. this peptide transport system resembles the recently cloned and sequenced secondary di- and tripeptide transport system of lactococcus lactis (a. hagting, e. r. s. kunji, k. j. leenhouts, b. poolman, and w. n. konings, j. biol. chem. 269:11391-11399, 1994). the peptide permease of l. monocytogenes has a broad substrate specificity and allows transport of the nonpeptide substrate 5-aminolevuli ... | 1995 | 7887604 |
| a 7-base-pair sequence protects dna from exonucleolytic degradation in lactococcus lactis. | linear dna molecules are subject to degradation by various exonucleases in vivo unless their ends are protected. it has been demonstrated that a specific 8-bp sequence, 5'-gctggtgg-3', named chi, can protect linear double-stranded dna from the major escherichia coli exonuclease recbcd. chi protects linear replication products of rolling-circle plasmids from recbcd degradation in vivo, in agreement with observations in vitro. a unique 7-bp sequence, 5'-gcgcgtg-3', is shown to protect similar repl ... | 1995 | 7892255 |
| sequence of the afg3 gene encoding a new member of the ftsh/yme1/tma subfamily of the aaa-protein family. | a nuclear gene from saccharomyces cerevisiae was cloned by genetic complementation of a temperature-sensitive respiratory-deficient mutant. dna sequence analysis reveals that it encodes a protein with homology to yme1, ftsh and tma, proteins which belong to the aaa-protein family (atpases associated with diverse cellular activities). the members of this family are involved in very different biological processes. yme1p, a yeast mitochondrial protein, affects the rate of dna escape from mitochondr ... | 1994 | 7900428 |
| xaa-pro-dipeptidyl-aminopeptidase from lactococcus lactis catalyses kinetically controlled synthesis of peptide bonds involving proline. | xaa-pro-dipeptidyl-aminopeptidase (ec 3.4.14.5) from lactococcus lactis (pepx) was used, for the first time, as a catalyst in kinetically controlled synthesis of peptide bonds involving proline. pepx had amidase and esterase activities in addition to peptidase activity. thus amide and ester derivatives of x-pro peptides could be employed as acyl donors. pepx showed a broad specificity for the residue in position p'1, accepting a large variety of amino acid amides, esters, peptides as well as fre ... | 1994 | 7917062 |
| expression, purification, and characterization of thymidylate synthase from lactococcus lactis. | the thymidylate synthase (ts) gene from lactococcus lactis has been highly expressed in escherichia coli. the ts protein was purified by sequential chromatography on q-sepharose and phenyl-sepharose. six grams of cell pellet yielded 140 mg of homogeneous ts. ts is a highly conserved enzyme, and several of the conserved amino acid residues that have been implicated in catalytic function are altered in l. lactis ts. by use of a 3-dimensional homology model, we have predicted covariant changes that ... | 1994 | 7920258 |
| study of gene transfer in vitro and in the digestive tract of gnotobiotic mice from lactococcus lactis strains to various strains belonging to human intestinal flora. | the use of genetically modified organisms (gmo) in dairy products requires evaluation of the dna transfer capacity from such organisms among the human intestinal microflora. thus, both in vitro and in vivo [in the digestive tract (dt) of mice] transfer from lactococcus lactis donor strains of the conjugative plasmid pil205 (cmr) and the non-conjugative plasmid pil253 (emr) to: (1) recipient strains isolated from human faecal flora bacteroides sp., bifidobacterium sp., peptostreptococcus sp. (str ... | 1994 | 7921350 |
| 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 |
| gene cloning and characterization of pepc, a cysteine aminopeptidase from streptococcus thermophilus, with sequence similarity to the eucaryotic bleomycin hydrolase. | streptococcus thermophilus cnrz 302 contains at least three general aminopeptidases able to hydrolyze phe-beta-naphthylamide substrate. the gene encoding one of these aminopeptidases was cloned from a total dna library of s. thermophilus cnrz 302 constructed in escherichia coli tg1 using pbluescript plasmid. the wild-type tg1 strain, although not deficient in aminopeptidase activity, is unable to hydrolyze the substrate phe-beta-naphthylamide, and thus the library could be screened with an enzym ... | 1994 | 7925365 |
| characterization and expression of the lactobacillus helveticus pepc gene encoding a general aminopeptidase. | an aminopeptidase c gene (pepc) was detected by nucleic acid hybridization from an industrially important lactobacillus helveticus strain. three hybridization positive clones were isolated from a gene library of this l. helveticus strain, and one of them was characterized in more detail. deletion mapping localized the hybridization positivity into a 2.8-kb fragment, which also encoded aminopeptidase activity. this fragment was sequenced and two open reading frames (orf1 and 2) of 1347 and 840 ba ... | 1994 | 7925424 |
| confirmation of the existence of a third family among peptidyl-prolyl cis/trans isomerases. amino acid sequence and recombinant production of parvulin. | in addition to the major cyclophilin-like peptidyl-prolyl cis/trans isomerases (ppiases) of escherichia coli an enzyme of very low relative molecular mass (10.1 kda) was discovered in this organism which gave first indication of the existence of a novel family in this enzyme class [1994, febs lett. 343, 65-69]. in the present report we describe the chemically determined amino acid sequence of four peptides derived from the 10.1 kda protein by the treatment with either cyanogen bromide or endopro ... | 1994 | 7925971 |
| theta replication of the lactococcal plasmid pwvo2. | pwvo2 is a 3.8 kb narrow-host-range plasmid from lactococcus lactis ssp. cremoris wg2, which does not replicate in bacillus subtilis or escherichia coli. single-stranded pwvo2 dna was not observed in lactococcal cells, indicating that this plasmid does not replicate via a rolling-circle mechanism. the sequence of pwvo2 neither showed the structural organization typical for rolling-circle plasmids, nor were sequence similarities with known rolling-circle plasmids present. by 2-d agarose gel elect ... | 1993 | 7934823 |
| molecular analysis of the lactococcus lactis subspecies lactis cnrz270 bidirectional theta replicating lactose plasmid pucl22. | pucl22 is the lactose protease plasmid of lactococcus lactis ssp. lactis cnrz270. the nucleotide sequence of its replication region rep22 contains a non-transcribed region, the replication origin, followed by a gene encoding a putative 388-amino-acid protein named rep22a. the promoter regions of the rep22a and pc194 cat genes share strong similarities and the pucl22 replicon exerted trans or cis negative control on the pc194 cat gene expression in l. lactis. we suggest that rep22a binds to its o ... | 1993 | 7934861 |
| the lactococcus lactis sex-factor aggregation gene clua. | a gene, clua, was cloned from the chromosomally located sex factor of lactococcus lactis mg1363. sequence analysis revealed significant homology with previously described aggregation proteins in enterococcus and streptococcus species. the possibility that clua was an equivalent protein involved in cell aggregation between donor and recipient bacteria during lactococcal conjugation was confirmed by its expression under the control of a heterologous promoter in l. lactis. analysis of the homology ... | 1994 | 7934889 |
| controlled expression and structural organization of a lactococcus lactis bacteriophage lysin encoded by two overlapping genes. | the phi vml3 bacteriophage lysin is specific for lactococci and could be used to promote enzyme release during cheese manufacture. the level of lysin expression from the cloned gene using its own upstream sequences is very low. expression in escherichia coli by using a synthetic hybrid lysin gene and a series of bal 31 deletions of the original cloned dna fragment suggested that the start of the gene had previously been incorrectly assigned. reevaluation of homology between the lysin and bacillu ... | 1994 | 7944354 |
| prevention of c-terminal autoprocessing of lactococcus lactis sk11 cell-envelope proteinase by engineering of an essential surface loop. | the catalytic domain of the cell-envelope proteinase from lactococcus lactis sk11 has various inserts, situated in external loops of the catalytic domain, compared with the related subtilisins. protein engineering was employed to analyse the necessity and function of one of these extra loops (residues 205-219), that is predicted to be located in close proximity to the substrate-binding region and is susceptible to autoproteolysis. we constructed a deletion mutant which lacks 14 residues of this ... | 1994 | 7945226 |
| genetics of lactose utilization in lactic acid bacteria. | lactose utilization is the primary function of lactic acid bacteria used in industrial dairy fermentations. the mechanism by which lactose is transported determines largely the pathway for the hydrolysis of the internalized disaccharide and the fate of the glucose and galactose moieties. biochemical and genetic studies have indicated that lactose can be transported via phosphotransferase systems, transport systems dependent on atp binding cassette proteins, or secondary transport systems includi ... | 1994 | 7946468 |
| temporal transcription map of the lactococcus lactis bacteriophage sk1. | bacteriophage sk1 is a small isometric-headed lytic phage that infects lactococcus lactis. the phage has a linear double-stranded dna genome of 28 kbp, with cohesive ends. rna was prepared from phage-infected l. lactis cells harvested at various intervals after infection, and the rna molecules were resolved by electrophoresis. northern blots of these gels were hybridized with sk1 dna probes and the results obtained from these experiments, together with the results of primer extension analyses, e ... | 1994 | 7952177 |
| nucleotide sequence and structural organization of the small, broad-host-range plasmid pci411 from leuconostoc lactis 533. | the nucleotide sequence of the leuconostoc lactis 533 cryptic plasmid pci411 (2926 bp) was determined. analysis revealed the presence of three open reading frames (orfs). orf 1 was capable of encoding a 24.9 kda peptide which shared homology with the replication initiation protein (repb) from a number of gram-positive rolling circle plasmids. orf 2 could encode a peptide of 6.6 kda which was homologous to the repc protein of the lactococcal plasmid pwv01. a function could not be assigned to orf ... | 1994 | 7952178 |
| cloning and expression of the plasmid encoded beta-d-galactosidase gene from a lactobacillus plantarum strain of dairy origin. | the beta-galactosidase (beta-gal) gene from lactobacillus plantarum c3.8 was cloned and expressed in lactococcus lactis and escherichia coli. hybridization experiments indicated that the gene is located on a plasmid and is present in other strains of lactobacillus plantarum. its sequence is very similar to a leuconostoc lactis beta-gal gene. expression of the gene, both in lactobacillus plantarum and in lactococcus lactis, was four-fold higher in cells growth in lactose compared to those grown i ... | 1994 | 7958766 |
| heterogeneric conjugal transfer of the pheromone-responsive plasmid pip964 (inchlyi) of enterococcus faecalis in the apparent absence of pheromone induction. | erythromycin-resistant derivatives of the pheromone-responsive plasmid pip964 from enterococcus faecalis were constructed to study its host range. this was done by inserting the integrative vector pat112 and the related replicon ptcr1 harboring orir of the broad host range plasmid pam beta 1 into the hemolysin-bacteriocin operon of pip964, to give ptcr2 and ptcr3, respectively. plasmid ptcr2 was transferred by filter matings from e. faecalis to enterococcus faecium and listeria monocytogenes at ... | 1994 | 7958769 |
| characteristics of vagococcus salmoninarum isolated from diseased salmonid fish. | isolates of the salmonid pathogen vagococcus salmoninarum were recovered from atlantic salmon, rainbow trout and brown trout with peritonitis. the phenotypes of these isolates and the type strain of vag. salmoninarum ncfb 2777 were determined by morphological, biochemical and physiological tests and whole cell protein profiles by sds-page. there was a high level of phenetic similarity between the salmonid isolates and the type strain. the species forms short gram-positive rods, hydrolyses l-pyrr ... | 1994 | 7961194 |
| cloning and characterization of upp, a gene encoding uracil phosphoribosyltransferase from lactococcus lactis. | uracil phosphoribosyltransferase catalyzes the key reaction in the salvage of uracil in many microorganisms. the gene encoding uracil phosphoribosyltransferase (upp) was cloned from lactococcus lactis subsp. cremoris mg1363 by complementation of an escherichia coli mutant. the gene was sequenced, and the putative amino acid sequence was deduced. the promoter was mapped by both primer extension and analysis of beta-galactosidase expressed from strains carrying fusion between upp promoter fragment ... | 1994 | 7961396 |
| mutational analysis of cat-86 gene expression controlled by lactococcal promoters in lactococcus lactis subsp. lactis and escherichia coli. | promoters were cloned from the chromosomal dna of lactococcus lactis subsp. lactis np4510 by using promoter-probe vector pgkv210. n-methyl-n'-nitro-n-nitrosoguanidine-induced mutagenesis of l. lactis-(pbv413), with low-level expression of the cat-86 gene, resulted in enhanced expression. subcloning and sequencing of the mutated plasmid designated pbv415 revealed that the mutation is located within the psti-hindiii fragment containing the coding sequence of the cat-86 gene (the 10th ctg codon was ... | 1994 | 7961430 |
| proton motive force-driven and atp-dependent drug extrusion systems in multidrug-resistant lactococcus lactis. | three mutants of lactococcus lactis subsp. lactis mg1363, termed ethr, daur, and rhor, were selected for resistance to high concentrations of ethidium bromide, daunomycin, and rhodamine 6g, respectively. these mutants were found to be cross resistant to a number of structurally and functionally unrelated drugs, among which were typical substrates of the mammalian multidrug transporter (p-glycoprotein) such as daunomycin, quinine, actinomycin d, gramicidin d, and rhodamine 6g. the three multidrug ... | 1994 | 7961458 |
| comparative analysis of gene expression in streptococcus pneumoniae and lactococcus lactis. | the pfl10 plasmid vector for translational fusions was constructed. pfl10 is based in the promiscuous pls1 replicon and contains the pc194 cat gene deprived of its transcriptional promoter and shine-dalgarno (sd) sequence. three promoters (pcit, ppola and ptetl) from gram-positive bacteria, inserted in pfl10, were tested for their ability to drive transcription in lactococcus lactis and streptococcus pneumoniae. these promoters were coupled to the sd sequence of the lactococcal citp gene fused t ... | 1994 | 7988870 |
| aminopeptidase n from streptococcus salivarius subsp. thermophilus ncdo 573: purification and properties. | a 96 kda aminopeptidase was purified from streptococcus salivarius subsp. thermophilus ncdo 573. the enzyme had similar properties to aminopeptidases isolated from lactococci and lactobacilli and showed a high degree of n-terminal amino acid sequence homology to aminopeptidase n from lactococcus lactis subsp. cremoris. it catalysed the hydrolysis of a range of aminoacyl 4-nitroanilides and 7-amido-4-methylcoumarin derivatives, dipeptides, tripeptides and oligopeptides. in common with aminopeptid ... | 1994 | 7989254 |
| a lactococcus lactis gene encodes a membrane protein with putative atpase activity that is homologous to the essential escherichia coli ftsh gene product. | a gene, encoding a protein homologous to an essential escherichia coli protein, ftsh, was identified adjacent to the hpt gene and the trna operon in the gram-positive bacterium lactococcus lactis. the deduced amino acid sequence of the gene product showed full-length similarity to ftsh of e. coli, yme1p of saccharomyces cerevisiae and a conserved region found in a new family of putative atpases. in-frame fusions of l. lactis ftsh and phoa1 in e. coli, and immunodetection of the l. lactis ftsh pr ... | 1994 | 8000529 |
| genetic studies of lactococcal bacteriophages--taxonomic differentiations and dna analysis: evidence for 3' cohesive ends. | twenty-four bacteriophages of lactococcus lactis subsp. lactis and l. lactis subsp. cremoris were classified. two groups of bacteriophages morphologically defined as prolate or isometric types by electron microscopy were examined for their genome sizes, protein patterns and dna homologies. these criteria showed that prolate phages are quite homogeneous. in contrast, isometric phages exhibit more differences, particularly in particle sizes and protein compositions. analysis of dna hybridizations ... | 1994 | 8005832 |
| microencapsulation of lactococcus lactis subsp. cremoris. | lactococcus lactis subsp. cremoris was microencapsulated within alginate/poly-l-lysine (alg/pll), nylon or crosslinked polyethyleneimine (pei) membranes. toxic effects were observed with solvents and reagents used in nylon and pei membrane formation. alg/pll encapsulation resulted in viable and active cell preparations which acidified milk at a rate proportional to the cell concentration, but at rates less than that of free cell preparations. at 4 x 10(8) colony-forming units (cfu/ml milk), enca ... | 1994 | 8006766 |
| 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 |
| pediocin a, a bacteriocin produced by pediococcus pentosaceus fbb61. | pediocin a, a bacteriocin produced by pediococcus pentosaceus fbb61, was purified and partially characterized. the purification was achieved by dialysis against peg 20,000, butanol extraction and electroendosmotic preparative electrophoresis. the protocol led to a 7843-fold increase in the specific activity, with 3.9% activity recovered. sds-page of pediocin a resulted in a single 80 kda protein band. the antimicrobial compound was sensitive to proteolytic enzymes and heat (10 min at 100 degrees ... | 1994 | 8012591 |
| purification and characterization of an endopeptidase from lactococcus lactis subsp. cremoris sk11. | an endopeptidase has been purified from lactococcus lactis subsp. cremoris sk11. the enzyme is a 70 kda monomer, strongly inhibited by the metalloproteinase inhibitors 1,10-phenanthroline and phosphoramidon but relatively insensitive to edta. it is not significantly inhibited by the thiol enzyme inhibitor p-chloromercuribenzoate nor by the serine protease inhibitor phenylmethylsulphonyl fluoride. the action of the endopeptidase in catalysing the hydrolysis of several peptide hormones has been st ... | 1994 | 8012609 |
| identification and characterization of the alpha-acetolactate synthase gene from lactococcus lactis subsp. lactis biovar diacetylactis. | the conversion of 3-13c-labelled pyruvate in an acetoin-producing clone from a lactococcus lactis subsp. lactis biovar diacetylactis strain dsm 20384 plasmid bank in escherichia coli was studied by 13c nuclear magnetic resonance analysis. the results showed that alpha-acetolactate was the first metabolic product formed from pyruvate, whereas acetoin appeared at a much slower rate and reached only low concentrations. this alpha-acetolactate production shows that the cells express the gene for alp ... | 1994 | 8017926 |
| cloning, expression, and nucleotide sequence of genes involved in production of lactococcin dr, a bacteriocin from lactococcus lactis subsp. lactis. | the partial nucleotide sequence of a lactococcus lactis subsp. lactis adria 85lo30 bacteriocin-producing operon was determined. the first two open reading frames of the operon are necessary to get bacteriocin expression in l. lactis il1403r. | 1994 | 8017945 |
| two different dihydroorotate dehydrogenases in lactococcus lactis. | the pyrimidine de novo biosynthesis pathway has been characterized for a number of organisms. the general pathway consists of six enzymatic steps. in the characterization of the pyrimidine pathway of lactococcus lactis, two different pyrd genes encoding dihydroorotate dehydrogenase were isolated. the nucleotide sequences of the two genes, pyrda and pyrdb, have been determined. one of the deduced amino acid sequences has a high degree of homology to the saccharomyces cerevisiae dihydroorotate deh ... | 1994 | 8021180 |
| conjugative transposition of tn916: preferred targets and evidence for conjugative transfer of a single strand and for a double-stranded circular intermediate. | transposition of conjugative transposons proceeds by excision and formation of a covalently closed circular intermediate that includes at its joint the six flanking bases from its previous host (coupling sequences). to elucidate the role of the coupling sequences in this process and to determine the sequence of targets used by tn916, we studied its insertion into a plasmid following conjugation. the results differ from those previously observed when tn916 was introduced by transformation. they s ... | 1994 | 8022279 |
| identification of the putative repressor-encoding gene ci of the temperate lactococcal bacteriophage tuc2009. | the putative repressor-encoding gene ci of the temperate lactococcal bacteriophage tuc2009 was cloned and sequenced. in the inferred amino-acid sequence, two domains can be recognized, one of which shows homology to dna-binding domains of various regulatory proteins, while the other is thought to be involved in oligomerisation. | 1994 | 8026765 |
| insertions of is256-like element flanking the chromosomal beta-lactamase gene of enterococcus faecalis cx19. | we have previously identified an inverted repeat characteristic of staphylococcal beta-lactamase transposons adjacent to the chromosomal beta-lactamase genes of enterococcus faecalis ch19 and its beta-lactamase-producing transconjugant cx19. nucleotide sequence analysis of the ch19 beta-lactamase structural gene (blaz) reveals it to be identical to the blaz gene from e. faecalis hh22 and to the blaz gene from the staphylococcal beta-lactamase transposon tn552. we also report the presence of nucl ... | 1994 | 8031032 |
| distribution and evolution of nisin-sucrose elements in lactococcus lactis. | the distribution, architecture, and conjugal capacity of nisin-sucrose elements in wild-type lactococcus lactis strains were studied. element architecture was analyzed with the aid of hybridizations to different probes derived from the nisin-sucrose transposon tn5276 of l. lactis nizo r5, including its left and right ends, the nisa gene, and is1068 (previously designated iso-is904), located between the left end and the nisa gene. three classes of nisin-sucrose elements could be distinguished in ... | 1994 | 8031080 |
| molecular characterization of lactococcal bacteriophage tuc2009 and identification and analysis of genes encoding lysin, a putative holin, and two structural proteins. | bacteriophage tuc2009 is a temperate bacteriophage with a small isometric head and is isolated from lactococcus lactis subsp. cremoris uc509. the phage genome is packaged by a headful mechanism, giving rise to circularly permuted molecules with terminal redundancy. the unit genome size is approximately 39 kb. a map of the phage genome on which several determinants could be localized was constructed: pac, the site of initiation of dna packaging; lys (1,287 bp), specifying the phage lysin; s (267 ... | 1994 | 8031083 |
| direct screening of recombinants in gram-positive bacteria using the secreted staphylococcal nuclease as a reporter. | a system for direct screening of recombinant clones in lactococcus lactis, based on secretion of the staphylococcal nuclease (snase) in the organism, was developed. the nuc gene (encoding snase) was cloned on both rolling-circle and theta-replicating plasmids. l. lactis strains containing these nuc+ plasmids secrete snase and are readily detectable by a simple plate test. a multicloning site (mcs) was introduced just after the cleavage site between leader peptide and the mature snase, without af ... | 1994 | 8051029 |
| effect of sodium dodecylsulphate on the binding of lactococcus lactis subsp. lactis t-80 cells with trp-p1. | | 1994 | 8063968 |
| purification and characterization of two phosphoglucomutases from lactococcus lactis subsp. lactis and their regulation in maltose- and glucose-utilizing cells. | two distinct forms of phosphoglucomutase were found in lactococcus lactis subsp. lactis, strains 19435 and 65.1, growing on maltose: beta-phosphoglucomutase (beta-pgm), which catalyzes the reversible conversion of beta-glucose 1-phosphate to glucose 6-phosphate in the maltose catabolism, and alpha-phosphoglucomutase (alpha-pgm). beta-pgm was purified to more than 90% homogeneity in crude cell extract from maltose-grown lactococci, and polyclonal antisera to the enzyme were prepared. the molecula ... | 1994 | 8071206 |
| identification of int and attp on the genome of lactococcal bacteriophage tuc2009 and their use for site-specific plasmid integration in the chromosome of tuc2009-resistant lactococcus lactis mg1363. | the dna sequence of the int-attp region of the small-isometric-headed lactococcal bacteriophage tuc2009 is presented. in this region, an open reading frame, int, which potentially encodes a protein of 374 amino acids, representing the tuc2009 integrase, was identified. the nucleotide sequence of the bacteriophage attachment site, attp, and the sequences of attb, attl, and attr in the lysogenic host lactococcus lactis subsp. cremoris uc509 were determined. a sequence almost identical to the uc509 ... | 1994 | 8074513 |
| purification and properties of the alpha-acetolactate decarboxylase from lactococcus lactis subsp. lactis ncdo 2118. | alpha-acetolactate decarboxylase from lactococcus lactis subsp. lactis ncdo 2118 was expressed at low levels in cell extracts and was also unstable. the purification was carried out from e. coli in which the enzyme was expressed 36-fold higher. the specific activity was 24-fold enhanced after purification. the main characteristics of alpha-acetolactate decarboxylase were: (i) activation by the three branched chain amino acids leucine, valine and isoleucine; (ii) allosteric properties displayed i ... | 1994 | 8076701 |
| the immune response to lactococcus lactis: implications for its use as a vaccine delivery vehicle. | the development of natural antibodies to lactococcus lactis in three inbred strains of mice and the effect of inoculating l. lactis into these mice has been investigated. all animals developed detectable levels of natural (systemic and secretory) anti-lactococcal antibodies. systemic anti-lactococcal antibodies were principally igg in young mice. an increase in anti-lactococcal igm occurred in all older animals. inoculation of l. lactis strains mg1820 or mg1363 by the oral and parenteral routes ... | 1994 | 8076800 |
| genetic analysis of the minimal replicon of the lactococcus lactis subsp. lactis biovar diacetylactis citrate plasmid. | using a combination of mutagenesis with the transposon gamma delta and polymerase chain reaction subcloning, the essential elements of the replication region of the lactococcus lactis subsp. lactis biovar diacetylactis citrate plasmid have been identified. an open reading frame, coding for a protein with homology to rep proteins from other lactococcus plasmids, is essential. this protein is trans-acting and could not be replaced by the rep protein from another lactococcus plasmid. a second open ... | 1994 | 8078463 |
| the majority of lactococcal plasmids carry a highly related replicon. | dna sequence analysis and southern hybridizations, together with complementation experiments, were used to study relationships between lactococcal plasmid replicons. pwvo2, pwvo4 and pwvo5, which co-exist in lactococcus lactis subsp. cremoris wg2, and pil7 (isolated from another strain) all contained a functional replication region which appeared to be very similar to that of some known lactococcal plasmids. they contain a gene encoding a highly conserved repb protein (60-80% amino acid identity ... | 1994 | 8081493 |
| cloning, sequencing and comparison of three lactococcal l-lactate dehydrogenase genes. | the conversion of pyruvate to lactate is a key feature of lactococcal strains. the enzyme which facilitates this conversion, l-lactate dehydrogenase (ldh), and the gene which encodes it (idh), are therefore of great significance. this paper presents the cloning and dna sequence analysis of three further lactococcal genes which are of key importance in the genetic manipulation of commercial starter strains. the idh gene from lactococcus lactis subsp. lactis biovar diacetylactis bu2-60 has been is ... | 1994 | 8081494 |
| membrane-associated proteins encoded by the nisin gene cluster may function as a receptor for the lantibiotic carnocin ui49. | carnocin ui49, a lantibiotic produced by carnobacterium piscicola shows bactericidal activity against many lactic acid bacteria. this paper describes the results of a study on the mode of action of carnocin ui49. it has previously been observed that nisin-producing lactococcus lactis subsp. lactis strains are at least 10-fold more sensitive to carnocin ui49 relative to other lactic acid bacteria. addition of carnocin ui49 to cells of l. lactis subsp. lactis nz9700 resulted in a dissipation of th ... | 1994 | 8081505 |
| bglr protein, which belongs to the bglg family of transcriptional antiterminators, is involved in beta-glucoside utilization in lactococcus lactis. | a fragment of the lactococcus lactis chromosome containing an open reading frame of 265 codons, denoted bglr, has been characterized. the polypeptide encoded by bglr shares 36 to 30% sequence identity with a family of regulatory proteins including arbg from erwinia chrysanthemi, bglg from escherichia coli, and sact and sacy from bacillus subtilis. these regulatory proteins are involved in positive control of the utilization of different sugars by transcription antitermination. for some of these ... | 1994 | 8083160 |
| quaternary ammonium compounds in milk: detection by reverse-phase high performance liquid chromatography and their effect on starter growth. | a reverse-phase hplc method is described that permits detection of quaternary ammonium sanitizers in milk. the commercial mixture of quaternary ammonium sanitizer used, n-alkyl (50% c14, 40% c12, and 10% c16) dimethyl benzyl ammonium chloride, was extracted from raw and homogenized milks by the mojonnier milk fat extraction protocol, selectively eluted from the reverse-phase column in the presence of organic solvent and ion-pairing agent, and then analyzed by diode array detection at 217 and 280 ... | 1994 | 8083408 |
| monoclonal antibody-based enzyme immunoassay for pediocins of pediococcus acidilactici. | monoclonal antibody (mab) r2-ar against pediocin rs2 was developed. mice were immunized for 12 weeks with pediocin rs2 conjugated to a polyacrylamide gel. two hybridoma fusions yielded an mab that in western blots (immunoblots) reacted only with pediocins rs2 and ach (3 kda) from pediococcus acidilactici rs2 and h, respectively, and did not react with any other bacteriocin, including sakacin a from lactobacillus sake lb 706, leuconocin lcm1 from leuconostoc carnosum lm1, nisin from lactococcus l ... | 1994 | 8085814 |
| [the development of a nutrient medium for nisin-producing streptococci utilizing the waste products from a number of biotechnology plants]. | the possibility of using some waste products of the dairy and agricultural industries as nutrient substrates for the cultivation of nisin-producing streptococci was studied. yeast production wastes as well as potato liquor, whey and dried whey as waste products were shown suitable for the growth of streptococcus lactis and the biosynthesis of nisin. the level of the nisin production increased when corn steep liquor and glucose were added to whey and dried whey respectively. | 1993 | 8085890 |
| a conserved sequence in trna and rrna promoters of lactococcus lactis. | a trna operon (trna) from lactococcus lactis consisting of seven trna genes and a 5s rrna gene was cloned and sequenced. promoter-fusion of the trna promoter to a promoter-less beta-galactosidase gene of leuconostoc mesenteroides resulted in high levels of beta-galactosidase activity in l. lactis. searching for sequences with similarity to the sequence of the promoter region revealed a consensus sequence of promoters preceeding rrna operons and trna operons from lactococcus species including a n ... | 1994 | 8086451 |
| degradation and debittering of a tryptic digest from beta-casein by aminopeptidase n from lactococcus lactis subsp. cremoris wg2. | the mode of action of purified aminopeptidase n from lactococcus lactis subsp. cremoris wg2 on a complex peptide mixture of a tryptic digest from bovine beta-casein was analyzed. the oligopeptides produced in the tryptic digest before and after aminopeptidase n treatment were identified by analysis of the n- and c-terminal amino acid sequences and amino acid compositions of the isolated peptides and by on-line liquid chromatography-mass spectrometry. incubation of purified peptides with aminopep ... | 1993 | 8100130 |
| characterization of the lactococcal temperate phage tp901-1 and its site-specific integration. | the temperate lactococcal phage tp901-1, induced by uv light from lactococcus lactis subsp. cremoris 901-1, was characterized. the restriction map was found to be circular, and the packaging of tp901-1 dna was concluded to occur by a headful mechanism. the pac region was localized on the 38.4-kb phage genome. tp901-1 belongs to the class of p335 phages (v. braun, s. hertwig, h. neve, a. geis, and m. teuber, j. gen. microbiol. 135:2551-2560, 1989). evidence is presented that the phages tp936-1 (v ... | 1994 | 8106318 |
| influence of amino acid substitutions in the nisin leader peptide on biosynthesis and secretion of nisin by lactococcus lactis. | structural genes for small lanthionine-containing antimicrobial peptides, known as lantibiotics, encode n-terminal leader sequences which are not present in the mature peptide, but are cleaved off at some stage in the maturation process. leader sequences of the different lantibiotics share a number of identical amino acid residues, but they are clearly different from sec-dependent protein export signal sequences. we studied the role of the leader sequence of the lantibiotic nisin, which is produ ... | 1994 | 8106398 |
| carnocin ui49, a potential biopreservative produced by carnobacterium piscicola: large scale purification and activity against various gram-positive bacteria including listeria sp. | this paper describes a simple purification method for the purification of carnocin ui49, a potential biopreservative produced by carnobacterium piscicola ui49. the protocol was also applicable for the isolation of nisin z, which is a biopreservative produced by lactococcus lactis sik-83. the protocol consists of only two purification steps, xad chromatography and cation exchange chromatography. it is quick, easy, and can be used for large scale purification of these lantibiotics. the bactericida ... | 1993 | 8110598 |
| antimicrobial activity of neutralized extracellular culture filtrates of lactic acid bacteria isolated from a cultured indian milk product ('dahi'). | neutralized extracellular culture filtrate obtained from isolates of lactobacillus acidophilus, lactobacillus delbruecki ssp. bulgaricus, lactobacillus salivarius and lactococcus lactis ssp. lactis from 'dahi' showed weak to moderate inhibition of staphylococcus aureus, bacillus cereus, escherichia coli, bacillus brevis, bacillus circulans, bacillus coagulans, bacillus laterosporus, bacillus subtilis and pseudomonas aeruginosa when tested by the diffusion agar well assay method. the effective mi ... | 1993 | 8110603 |
| gene transfer from engineered lactococcus lactis strains to enterococcus faecalis in the digestive tract of gnotobiotic mice. | the introduction of genetically modified organisms into food products requires an evaluation of the behaviour and the dissemination of foreign genes of such organisms among the human intestinal microflora. the conjugal transfer, both in vitro and in vivo (in mice digestive tract) of dna from lactococcus lactis donor strains to an enterococcus faecalis strain isolated from human faecal flora was studied. we followed the transfer of (1) the self-transmissible plasmid pil205; (2) two non-self-trans ... | 1993 | 8111532 |
| identification of genes encoding ribosomal protein l33 from bacillus licheniformis, thermus thermophilus and thermotoga maritima. | three previously unrecognized genes from bacillus licheniformis, thermus thermophilus and thermotoga maritima, encoding ribosomal protein l33, have been identified and designated as rpmg genes. their sequence and context have been compared with the three known rpmg genes from escherichia coli, lactococcus lactis and b. subtilis. previously unrecognized open reading frames homologous to sece are located immediately downstream from rpmg in b. licheniformis, t. thermophilus and ta. maritima: beyond ... | 1994 | 8112583 |
| nucleotide metabolism in lactococcus lactis: salvage pathways of exogenous pyrimidines. | by measuring enzyme activities in crude extracts and studying the effect of toxic analogs (5-fluoropyrimidines) on cell growth, the metabolism of pyrimidines in lactococcus lactis was analyzed. pathways by which uracil, uridine, deoxyuridine, cytidine, and deoxycytidine are metabolized in l. lactis were established. they are similar to those found in escherichia coli except that lactococci are unable to utilize cytosine. | 1994 | 8113193 |
| growth phase-dependent regulation and membrane localization of spab, a protein involved in biosynthesis of the lantibiotic subtilin. | the information responsible for biosynthesis of the lantibiotic subtilin is organized in an operon-like structure that starts with the spab gene. the spab gene encodes an open reading frame consisting of 1,030 amino acid residues, and it was calculated that a protein having a theoretical molecular mass of 120.5 kda could be produced from this gene. this is consistent with the apparent molecular weight for spab of 115,000 which was estimated after sodium dodecyl sulfate-gel electrophoresis and id ... | 1994 | 8117069 |
| characterization of the lactobacillus helveticus cnrz32 pepc gene. | sequence analysis of the aminopeptidase c gene (pepc) from lactobacillus helveticus cnrz32 identified a 1,332-nucleotide open reading frame coding for a polypeptide with motifs characteristic of cysteine proteinases. homology to the pepc gene appears to be widely distributed among lactic acid bacteria. | 1994 | 8117086 |
| analysis of the cos region of the lactococcus lactis bacteriophage sk1. | the location, structure and nature of the cos site of the lactococcus lactis bacteriophage sk1 was determined using a taq dna polymerase runoff sequencing technique. the cos site contains a single-stranded 3' overhang of 11 nucleotides. the region surrounding cos contains several features which may be involved in the binding and catalytic action of a phage terminase. these include four putative terminase-binding sites which show some homology to lambda r-sites, an 11-bp direct repeat, a 10-bp in ... | 1994 | 8125289 |
| cloning and sequence analysis of the dnak gene region of lactococcus lactis subsp. lactis. | a 5.4 kb hindiii fragment of lactococcus lactis subsp. lactis was identified using a homologous dnak probe generated by pcr and cloned in escherichia coli. upstream sequences were generated by inverse pcr. the two cloned fragments partially overlapped, and sequencing of 5915 bp revealed the presence of four open reading frames in the order orf1-grpe-dnak-orf4. orf1 encodes a 39 kda protein of unknown function which shows considerable sequence homology with the orf39 and orfa proteins of bacillus ... | 1993 | 8126443 |
| cloning and sequence analysis of the gene encoding lactococcus lactis malolactic enzyme: relationships with malic enzymes. | malolactic enzyme is the key enzyme in the degradation of l-malic acid by lactic acid bacteria. using degenerated primers designed from the first 20 n-terminal amino acid sequence of lactococcal malolactic enzyme, a 60-bp dna fragment containing part of the mles gene was amplified from lactococcus lactis in a polymerase chain reaction. this specific probe was used to isolate two contiguous fragments covering the gene as a whole. the 1.9-kb region sequenced contains an open reading frame of 1623 ... | 1994 | 8132158 |
| crystallization and preliminary x-ray analysis of pepc, a thiol aminopeptidase from lactoccocus lactis homologous to bleomycin hydrolase. | crystals of the recombinant thiol aminopeptidase pepc, from lactoccocus lactis, have been obtained using the hanging-drop method of vapor diffusion from ammonium sulfate solutions. crystals are rhombohedral, the space group is r32, a = 175.2 a, c = 94.5 a (hexagonal setting). the asymmetric unit probably contains one monomer of a hexameric molecule-arrangement of 300 kda which exhibits the crystallographic point group of symmetry 32. the crystals diffract to at least 3 a resolution. | 1994 | 8133515 |
| use of the escherichia coli beta-glucuronidase (gusa) gene as a reporter gene for analyzing promoters in lactic acid bacteria. | a transcriptional fusion vector, designated pnz272, based on the promoterless beta-glucuronidase gene (gusa) of escherichia coli as a reporter gene, has been constructed for lactic acid bacteria. the replicon of pnz272 was derived from the lactococcus lactis plasmid psh71, allowing replication in a wide range of gram-positive bacteria and e. coli. the applicability of pnz272 and the expression of the gusa gene in l. lactis was demonstrated in shotgun cloning experiments with lactococcal chromoso ... | 1994 | 8135517 |
| effect of a defined continuous-flow derived bacterial culture and dietary lactose on salmonella typhimurium colonization in broiler chickens. | a defined bacterial culture protective against salmonella typhimurium cecal colonization in broiler chicks was derived utilizing a continuous-flow (cf) culture apparatus. chicks receiving the cf culture in combination with a diet containing dietary lactose were protected against cecal colonization by s. typhimurium. the culture consisted of a mixture of gram-positive and gram-negative facultative and strictly anaerobic bacteria. the isolates were identified as enterococcus avium, two strains of ... | 1993 | 8141728 |
| bactericidal potency of hydroxyl radical in physiological environments. | rates of radiolytic inactivation of bacteria suspended in n2o-saturated solutions were dramatically increased over normal background levels when the media contained chloride or bicarbonate ions. the bacteria could be protected from this enhanced toxicity by the addition of free radical scavengers (ethanol, ascorbate, hydrogen peroxide, mannitol, glucose, edta, picolinic acid), indicating that the lethal reactions were extracellular in origin. prior irradiation of chloride-containing solutions le ... | 1994 | 8144563 |
| [antimicrobial activities of cefteram against recently clinically detected and isolated strains from patients with dental infections]. | to investigate the antibiotic activity of cefteram (cftm), the minimum inhibitory concentrations (mics) of cftm and of the control drugs were determined against clinically isolated strains received from november 1991 to april 1993 from 19 dental facilities throughout the country, as well as against clinically isolated strains from samples obtained at this center from patients with dental infectious diseases, and the following results were obtained. 1. 430 strains were detected in 198 cases but i ... | 1994 | 8151907 |