Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| efficient plasmid mobilization by pip501 in lactococcus lactis subsp. lactis. | pip501 is a streptococcal conjugative plasmid which can be transmitted among numerous gram-positive strains. to identify a minimal mobilization (mob) locus of pip501, dna fragments of pip501 were cloned into nonconjugative target plasmids and tested for mobilization by pip501. we show that nonmobilizable plasmids containing a specific fragment of pip501 are transmitted at high frequencies between lactococcus lactis subsp. lactis strains if transfer (tra) functions are provided in trans by a pip5 ... | 1993 | 8376328 |
| gene organization, primary structure and rna processing analysis of a ribosomal rna operon in lactococcus lactis. | southern blot analysis of genomic dna of the mesophilic lactic bacterium lactococcus lactis subsp. lactis strain il1403, illuminated six rrna gene clusters. each cluster contains one copy each of three rrna genes, displaying the typical eubacterial organization of physically linked 16 s, 23 s and 5 s rrna genes. five of the six rrna clusters were cloned into plasmid pbr322. one recombinant plasmid, pslcm6, containing a 6500 base-pair genomic dna fragment, was characterized by physical mapping an ... | 1993 | 8450551 |
| stability analysis of the lactococcus lactis drc1 lactose plasmid using pulsed-field gel electrophoresis. | pulsed-field agarose gel electrophoresis of smai digests of genomic dna was used to examine lactose plasmid copy number and stability in lactococcus lactis. in l. lactis strain drc1, the plasmid was found to exist as a single-copy plasmid. transconjugants of strain hid113 carrying this plasmid were unstable. variants were isolated with improved phenotypic stability resulting from improved maintenance of the lactose plasmid or from integration of part of the plasmid into the lactococcal chromosom ... | 1993 | 8441771 |
| analysis of a region from the bacteriophage resistance plasmid pci528 involved in its conjugative mobilization between lactococcus strains. | a 10-kb hindiii fragment of pci528 cloned into the nonconjugative shuttle vector pci3340 could be transferred by conjugative mobilization from lactococcus lactis subsp. lactis mg1363, whereas other hindiii fragments of pci528 or the vector alone were nonmobilizable. subcloning of this 10-kb region identified a 4.4-kb bglii-ecori fragment which contained all the dna essential for transfer. sequence analysis of a 2-kb region within this 4.4 kb-segment revealed a region rich in inverted repeats and ... | 1993 | 8376345 |
| characteristics and osmoregulatory roles of uptake systems for proline and glycine betaine in lactococcus lactis. | lactococcus lactis subsp. lactis ml3 contains high pools of proline or betaine when grown under conditions of high osmotic strength. these pools are created by specific transport systems. a high-affinity uptake system for glycine betaine (betaine) with a km of 1.5 microm is expressed constitutively. the activity of this system is not stimulated by high osmolarities of the growth or assay medium but varies strongly with the medium ph. a low-affinity proline uptake system (km, > 5 mm) is expressed ... | 1993 | 8366030 |
| two genes present on a transposon-like structure in lactococcus lactis are involved in a clp-family proteolytic activity. | the lactose-protease plasmid pucl22 of lactococcus lactis subsp. lactis strain cnrz270 contained two inverted copies of is 1076 flanking a region of 3.7 kb. this internal region was sequenced and found to contain two large open reading frames, orf1 and orfp in opposite orientations. orf1 consists of 2289 bp; the deduced 763-amino-acid sequence is similar to the atpases of the clpa family. it contains two well-conserved consensus atp-binding sites. it was named clpl. orfp consists of 930 bp encod ... | 1993 | 8387149 |
| copy number and location of insertion sequences iss1 and is981 in lactococci and several other lactic acid bacteria. | genomic dna from 49 lactococcal strains was screened by southern hybridization for the presence and relative copy number of lactococcal insertion sequence iss1: iss1 was found in 47 of 49 strains giving 1 to 20 hybridizing bands per strain. southern hybridizations of undigested plasmid dna from 17 lactococcal strains probed with iss1 and is981 showed that iss1 was present on plasmids in all 17 strains, whereas is981 was present on plasmids in 14 of the 17 strains. both insertion sequences were p ... | 1993 | 8389385 |
| insertion of lipids and proteins into bacterial membranes by fusion with liposomes. | 1993 | 8395638 | |
| energy transduction in lactic acid bacteria. | in the discovery of some general principles of energy transduction, lactic acid bacteria have played an important role. in this review, the energy transducing processes of lactic acid bacteria are discussed with the emphasis on the major developments of the past 5 years. this work not only includes the biochemistry of the enzymes and the bioenergetics of the processes, but also the genetics of the genes encoding the energy transducing proteins. the progress in the area of carbohydrate transport ... | 1993 | 8398212 |
| organization and regulation of genes for amino acid biosynthesis in lactic acid bacteria. | the recent description of large clusters of biosynthetic genes in the chromosome of lactococcus lactis and, to a lesser extent, of lactobacillus, has brought some information on gene organization and control of gene expression in these organisms. the genes involved in a given amino acid biosynthetic pathway are clustered at a single chromosomal location and form an operon. additional genes which are not required for the biosynthesis are present within some operons. genetic signals are, in genera ... | 1993 | 8398216 |
| in vitro pore-forming activity of the lantibiotic nisin. role of protonmotive force and lipid composition. | nisin is a lantibiotic produced by some strains of lactococcus lactis subsp. lactis. the target for nisin action is the cytoplasmic membrane of gram-positive bacteria. nisin dissipates the membrane potential (delta psi) and induces efflux of low-molecular-mass compounds. evidence has been presented that a delta psi is needed for nisin action. the in vitro action of nisin was studied on liposomes loaded with the fluorophore carboxyfluorescein. nisin-induced efflux of carboxyfluorescein was observ ... | 1993 | 8444179 |
| cloning, sequence and expression of the gene encoding the malolactic enzyme from lactococcus lactis. | many lactic acid bacteria can carry out malolactic fermentation. this secondary fermentation is mediated by the nad- and mn(2+)-dependent malolactic enzyme, which catalyses the decarboxylation of l-malate to l-lactate. the gene we call mles, coding for malolactic enzyme, was isolated from lactococcus lactis. the mles gene consists of one open reading frame capable of coding for a protein with a calculated molecular mass of 59 kda. the amino acid sequence of the predicted mles gene product is hom ... | 1993 | 8405453 |
| the use of bacterial luciferase genes as reporter genes in lactococcus: regulation of the lactococcus lactis subsp. lactis lactose genes. | lactose metabolism is an important industrial trait in dairy lactococci. in lactococcus lactis, lactose is taken up via the phosphoenolpyruvate-dependent phosphotransferase system (pep-pts) and is subsequently metabolized via the glycolytic and tagatose 6-phosphate pathways. genes for the lactose-specific pep-pts proteins, phospho-beta-galactosidase and tagatose 6-phosphate pathway enzymes are encoded by a single 8 kb operon, lacabcdfegx, and there is a divergently transcribed lacr repressor gen ... | 1993 | 8371112 |
| rapid isolation of genes from bacterial lambda libraries by direct polymerase chain reaction screening. | a method for the direct screening of bacterial lambda libraries by polymerase chain reaction technology has been developed. this technique permits the identification and isolation of specific dna sequences without the need for any filter hybridisation or radioactive probing. this strategy has been used to isolate a gene encoding lactate dehydrogenase from a lactococcus lactis lambda library. | 1993 | 8405949 |
| cloning, nucleotide sequence and expression in streptomyces lividans and escherichia coli of pabb from lactococcus lactis subsp. lactis ncdo 496. | a gene (pabb) encoding the aminase activity of p-aminobenzoate (paba) synthase in lactococcus lactis subsp. lactis was cloned in pij41 and expressed in streptomyces lividans strains defective in paba biosynthesis. expression of the gene was associated with a 1.2 kb deletion between the aph promoter and the cloning site in pij41. subcloning in pbr322 and expression in escherichia coli ab3295 of the cloned l. lactis dna fragment localized the pabb-complementing gene in a 1.9 kb segment. the nucleo ... | 1993 | 8409921 |
| functional analysis of the lactococcus lactis usp45 secretion signal in the secretion of a homologous proteinase and a heterologous alpha-amylase. | the ups45 gene encodes the major extracellular protein from lactococcus lactis. the deduced sequence of the 27 residue leader peptide revealed the tripartite characteristics of a signal peptide. this leader peptide directed the efficient secretion of the homologous proteinase (prtp) in l. lactis, indicating that the putative signal peptide of prtp can be replaced by the 27 residue usp45 leader peptide. in addition, the 27 residue leader peptide could be used to secrete the bacillus stearothermop ... | 1993 | 8413193 |
| 15n- and 13c-labeled media from anabaena sp. for universal isotopic labeling of bacteriocins: nmr resonance assignments of leucocin a from leuconostoc gelidum and nisin a from lactococcus lactis. | a procedure for universal 13c and/or 15n labeling of microbial peptides which are produced by fermentation in complex media and its application to two food-preserving bacteriocins from lactic acid bacteria are described. isotopic enrichment of nisin a (from lactococcus lactis) and of leucocin a (from leuconostoc gelidum) is readily achieved using a soluble peptone derived from enzymatic hydrolysis (pepsin and chymopapain) of anabaena sp. atcc 27899 cells grown on sodium [13c]bicarbonate and/or s ... | 1993 | 8418850 |
| properties of nisin z and distribution of its gene, nisz, in lactococcus lactis. | two natural variants of the lantibiotic nisin that are produced by lactococcus lactis are known. they have a similar structure but differ in a single amino acid residue at position 27; histidine in nisin a and asparagine in nisin z (j.w.m. mulders, i.j. boerrigter, h.s. rollema, r.j. siezen, and w.m. de vos, eur. j. biochem, 201:581-584, 1991). the nisin variants were purified to apparent homogeneity, and their biological activities were compared. identical mics of nisin a and nisin z were found ... | 1993 | 8439149 |
| cloning and sequencing of pepc, a cysteine aminopeptidase gene from lactococcus lactis subsp. cremoris am2. | a gene coding for an aminopeptidase (pepc) from lactococcus lactis subsp. cremoris am2 was cloned by complementation of an escherichia coli mutant lacking aminopeptidase activity. the nucleotide sequence was determined. a portion of the predicted amino acid sequence of pepc (436 amino acids) showed strong homology to the active site of cysteine proteases. no signal sequence was found, indicating an intracellular location of the enzyme. | 1993 | 8439160 |
| purification and characterization of a cell wall peptidase from lactococcus lactis subsp. cremoris imn-c12. | a peptidase from the cell wall fraction of lactococcus lactis subsp. cremoris imn-c12 has been purified to homogeneity by hydrophobic interaction chromatography, two steps of anion-exchange chromatography, and gel filtration. the molecular mass of the purified enzyme was estimated to be 72 kda by gel filtration and 23 kda by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. the enzyme has a pi of 4.0, and it has the following n-terminal sequence from the 2nd to the 17th amino acid resid ... | 1993 | 8215377 |
| septic arthritis and unpasteurised milk. | green-top, or unpasteurised, milk is an increasing source of illness. a case of a previously unreported cause of septic arthritis of the hip joint, secondary to the ingestion of raw milk is reported. | 1993 | 8254098 |
| nucleotide sequence of the lactococcus lactis ncdo 763 (ml3) rpod gene. | the complete nucleotide sequence of rpod gene from lactococcus lactis has been determined. the nucleotide data have indicated the presence of an open reading frame of 1020 base pairs encoding a polypeptide which shares the framework structure for principal sigma factors of eubacteria strains. | 1993 | 8218400 |
| detection, identification and characterization of bacteriocin-producing lactic acid bacteria from retail food products. | forty bacteriocin-producing (bac+) lactic acid bacteria (lab) were isolated from food samples purchased from retail supermarkets and local farms. of the 40 bac+ isolates, 18 were isolated from 85 food samples by enrichment (21% isolation rate) whereas eight were obtained from 63 samples by direct plating (13% isolation rate). by direct plating, bac+ lab were detected at levels up to 2.4 x 10(5) cfu/g in ready-to-eat meats. the bac+ isolates were identified by carbohydrate fermentation patterns, ... | 1993 | 8257654 |
| sequence analysis of the lysin gene region of the prolate lactococcal bacteriophage c2. | approximately 80% of the genome of the prolate-headed lactococcal bacteriophage c2 was cloned into shuttle vectors psa3 and pfx3 in escherichia coli and transferred to lactococcus lactis. a 1.67-kilobase ecorv fragment containing the gene for the phage lysin was identified and the position and orientation of the phage lysin gene in the physical map of the phage were determined. the phage lysin was expressed in e. coli and its sequence was determined and compared with the sequences of other bacte ... | 1993 | 8221377 |
| conjugal transfer of the determinants for bacteriocin (lacticin 481) production and immunity in lactococcus lactis subsp. lactis cnrz 481. | the lacticin 481-producer (lct+), l. lactis subsp. lactis (l. lactis) cnrz 481 harbours 5 plasmids of 6.5, 7.5, 20, 37 and 69 kb. novobiocin treatment of l. lactis 481 led to the appearance of lacticin 481 deficient variants which had all lost the 69 kb plasmid. conjugal transfer of the lacticin 481 structural gene (lct) into the plasmid free strain l. lactis il1441 yielded lct+ transconjugants at a 10(-4) frequency, which carried a plasmid with an apparent size of 120-130 kb. southern hybridiza ... | 1993 | 8224796 |
| a model system for the investigation of heterologous protein secretion pathways in lactococcus lactis. | the capacity of recombinant strains of lactococcus lactis to secrete a heterologous protein was investigated by constructing two expression-secretion vectors (plet2 and plet3) for use with a lactococcal gene expression system driven by the highly active t7 rna polymerase. the vectors incorporated different lactococcal secretion leaders and translation initiation sequences. when tetanus toxin fragment c (ttfc) was used as a test protein, the quantities of ttfc produced by the plet2-ttfc strain ex ... | 1993 | 8285699 |
| genetic and biochemical characterization of the oligopeptide transport system of lactococcus lactis. | the nucleotide sequence of a chromosomal dna fragment of lactococcus lactis subsp. lactis ssl135, previously implicated in peptide utilization, has been determined. the genes oppdfbca, encoding the oligopeptide transport system (opp), and that encoding the endopeptidase pepo were located on this 8.9-kb dna fragment. the oppdfbca and pepo genes are probably organized in an operon. analysis of the deduced amino acid sequences of the genes indicated that the oligopeptide transport system consists o ... | 1993 | 8244921 |
| differences in sensitivity to nadh of purified pyruvate dehydrogenase complexes of enterococcus faecalis, lactococcus lactis, azotobacter vinelandii and escherichia coli: implications for their activity in vivo. | the effect of nadh on the activity of the purified pyruvate dehydrogenase complexes (pdhc) of enterococcus (ec.) faecalis, lactococcus lactis, azotobacter vinelandii and escherichia coli was determined in vitro. it was found that the pdhc of e. coli and l. lactis was active only at relatively low nadh/nad ratios, whereas the pdhc of ec. faecalis was inhibited only at high nadh/nad ratios. the pdhc of azotobacter vinelandii showed an intermediate sensitivity. the organisms were grown in chemostat ... | 1993 | 8288104 |
| insertion sequence analysis of protoplast fused strains of lactococcus lactis ssp. cremoris. | the use of insertion sequence probes for the analysis of fusants obtained following protoplast fusion is described. hybridization of both total and plasmid dna from parent and fusant strains with probes to is904 and iss1 showed that of the four protoplast fusions examined, three appeared to involve a rearrangement of genetic material while in the fourth the fusant appeared similar to one of the parental strains. this method of analysis provides more information about the changes induced by proto ... | 1993 | 8270197 |
| lysines 72, 80 and 213 and aspartic acid 210 of the lactococcus lactis lacr repressor are involved in the response to the inducer tagatose-6-phosphate leading to induction of lac operon expression. | site-directed mutagenesis of the lactococcus lactis lacr gene was performed to identify residues in the lacr repressor that are involved in the induction of lacabcdfegx operon expression by tagatose-6-phosphate. a putative inducer binding domain located near the c-terminus was previously postulated based on homology studies with the escherichia coli deor family of repressors, which all have a phosphorylated sugar as inducer. residues within this domain and lysine residues that are charge conserv ... | 1993 | 8475045 |
| biosynthesis and secretion of a precursor of nisin z by lactococcus lactis, directed by the leader peptide of the homologous lantibiotic subtilin from bacillus subtilis. | the dna sequence encoding the leader peptide of the lantibiotic subtilin from bacillus subtilis was fused to the sequence encoding pronisin z, and this hybrid gene was expressed in a lactococcus lactis strain that produces nisin a. this strain simultaneously secreted nisin a and a protein of approximately 6 kda. amino acid sequencing of the purified 6 kda protein and structural analysis of its main tryptic fragment by two-dimensional 1h-nmr showed that it consists of the unmodified leader peptid ... | 1993 | 8370453 |
| improved cloning vectors and transformation procedure for lactococcus lactis. | four shuttle vectors (pmig 1, 2, 2h and 3) have been constructed based on the broad host-range plasmid pck1. all the pmig vectors possess a multiple cloning site containing 12 or more unique restriction enzyme sites, and are stably maintained at either high or low copy number in lactococcus lactis and in escherichia coli. by cloning the e. coli puc replicon into one of these vectors a plasmid was constructed which can replicate to high copy number in reca strains of e. coli. the broad host-range ... | 1993 | 8349525 |
| identification of a novel operon in lactococcus lactis encoding three enzymes for lactic acid synthesis: phosphofructokinase, pyruvate kinase, and lactate dehydrogenase. | the discovery of a novel multicistronic operon that encodes phosphofructokinase, pyruvate kinase, and lactate dehydrogenase in the lactic acid bacterium lactococcus lactis is reported. the three genes in the operon, designated pfk, pyk, and ldh, contain 340, 502, and 325 codons, respectively. the intergenic distances are 87 bp between pfk and pyk and 117 bp between pyk and ldh. plasmids containing pfk and pyk conferred phosphofructokinase and pyruvate kinase activity, respectively, on their host ... | 1993 | 8478320 |
| scrfi restriction-modification system of lactococcus lactis subsp. cremoris uc503: cloning and characterization of two scrfi methylase genes. | two genes from the total genomic dna of dairy starter culture lactococcus lactis subsp. cremoris uc503, encoding scrfi modification enzymes, have been cloned and expressed in escherichia coli. no homology between the two methylase genes was detected, and inverse polymerase chain reaction of flanking chromosomal dna indicated that both were linked on the lactococcus genome. neither clone encoded the cognate endonuclease. the dna sequence of one of the methylase genes (encoded by pci931m) was dete ... | 1993 | 8481004 |
| characterization of the lactococcus lactis nisin a operon genes nisp, encoding a subtilisin-like serine protease involved in precursor processing, and nisr, encoding a regulatory protein involved in nisin biosynthesis. | biosynthesis of the lantibiotic peptide nisin by lactococcus lactis nizo r5 relies on the presence of the conjugative transposon tn5276 in the chromosome. a 12-kb dna fragment of tn5276 including the nisa gene and about 10 kb of downstream dna was cloned in l. lactis, resulting in the production of an extracellular nisin precursor peptide. this peptide reacted with antibodies against either nisin a or the synthetic leader peptide, suggesting that it consisted of a fully modified nisin with the n ... | 1993 | 8478324 |
| cloning and sequencing of the lactococcus lactis subsp. lactis groesl operon. | the operon (groesl) coding for the lactococcus lactis subsp. lactis heat-shock proteins groel and groes, has been isolated and its complete nucleotide (nt) sequence determined. a set of degenerate pcr primers, deduced from amino acids which are conserved in a number of prokaryotic groels, were synthesized and used to amplify a 957-bp fragment. this pcr fragment was used as a probe to isolate a 5.0-kb ecori chromosomally derived fragment. a region of this 5.0-kb ecori fragment was sequenced and r ... | 1993 | 8486277 |
| monitoring tripeptidase activity using capillary electrophoresis. comparison with the ninhydrin assay. | capillary electrophoresis (ce) was used to assay the activity of a tripeptidase from a crude extract of lactococcus lactis subsp. lactis ncdo 712 against the substrate, gly-gly-phe and a comparison with a standard ninhydrin assay was made. standard curves of the substrates and products showed a significantly variable colorimetric reaction to ninhydrin making accurate quantification of the tripeptidase problematic. the ce assay further demonstrated that the presence of contaminating enzymes in cr ... | 1993 | 8491837 |
| influence of intracellular ph on light emission from a luxa/b derivative of lactococcus lactis subsp. diacetylactis. | high levels of constitutive aldehyde-dependent light emission were obtained from nongrowing cells of lactococcus lactis subsp. diacetylactis f712 transformed with iuxa/b when they were suspended in buffered solutions. inductions of light emission was time-dependent and was not due to growth, synthesis of luciferase or stimulation of metabolism by fermentable carbohydrate. the major factor controlling light emission in such cells appears to be the intracellular ph value. experiments with ionophor ... | 1993 | 8493883 |
| application of in vivo bioluminescence to the study of ionophoretic action. | ionophores (carbonyl cyanide m-chlorophenylhydrazone; valinomycin; and the hop-derived compounds colupulone, trans-isohumulone and trans-humulinic acid) reduced the rate of dodecanal-dependent light emission from iuxa/b-transformed cells of lactococcus lactis subsp. diacetylactis f712 when the cells were suspended in a buffered medium (ph 6.4) containing glucose. this allowed an assay for ionophores to be devised and permitted measurement of the effects of such compounds on the test organism by ... | 1993 | 8493884 |
| high-efficiency gene inactivation and replacement system for gram-positive bacteria. | a system for high-efficiency single- and double-crossover homologous integration in gram-positive bacteria has been developed, with lactococcus lactis as a model system. the system is based on a thermosensitive broad-host-range rolling-circle plasmid, pg+host5, which contains a pbr322 replicon for propagation in escherichia coli at 37 degrees c. a nested set of l. lactis chromosomal fragments cloned onto pg+host5 were used to show that the single-crossover integration frequency was logarithmical ... | 1993 | 8501066 |
| a simple, low energy requiring method of coagulating leaf proteins for food use. | a simple method for coagulating proteins in aqueous leaf extract, through microbial fermentation, has been reported. the leaf protein concentrate (lpc) obtained through this fermentation has been compared with those obtained through conventional heat coagulation methods to show that the former improves the yield and nutritional quality of lpc. | 1993 | 8506239 |
| cloning, nucleotide sequence, and regulatory analysis of the lactococcus lactis dnaj gene. | the dnaj gene of lactococcus lactis was isolated from a genomic library of l. lactis nizo r5 and cloned into puc19. nucleotide sequencing revealed an open reading frame of 1,137 bp in length, encoding a protein of 379 amino acids. the deduced amino acid sequence showed homology to the dnaj proteins of escherichia coli, mycobacterium tuberculosis, bacillus subtilis, and clostridium acetobutylicum. the level of the dnaj monocistronic mrna increased approximately threefold after heat shock. the tra ... | 1993 | 8449872 |
| di-tripeptides and oligopeptides are taken up via distinct transport mechanisms in lactococcus lactis. | lactococcus lactis ml3 possesses two different peptide transport systems of which the substrate size restriction and specificity have been determined. the first system is the earlier-described proton motive force-dependent di-tripeptide carrier (e. j. smid, a. j. m. driessen, and w. n. konings, j. bacteriol. 171:292-298, 1989). the second system is a metabolic energy-dependent oligopeptide transport system which transports peptides of four to at least six amino acid residues. the involvement of ... | 1993 | 8458848 |
| cloning and sequencing of the gene for a lactococcal endopeptidase, an enzyme with sequence similarity to mammalian enkephalinase. | the gene specifying an endopeptidase of lactococcus lactis, named pepo, was cloned from a genomic library of l. lactis subsp. cremoris p8-2-47 in lambda embl3 and was subsequently sequenced. pepo is probably the last gene of an operon encoding the binding-protein-dependent oligopeptide transport system of l. lactis. the inferred amino acid sequence of pepo showed that the lactococcal endopeptidase has a marked similarity to the mammalian neutral endopeptidase ec 3.4.24.11 (enkephalinase), wherea ... | 1993 | 8458851 |
| cloning and expression of the manganese superoxide dismutase gene of escherichia coli in lactococcus lactis and lactobacillus gasseri. | the escherichia coli soda gene encoding the antioxidant enzyme mn-containing superoxide dismutase (mnsod), was cloned in the expression vector pmg36e. this vector has a multiple cloning site downstream of a promoter and shine-dalgarno sequences derived from lactococcus. the protein-coding region of soda from e. coli was amplified by the polymerase chain reaction, using a thermocycler and taq dna polymerase before cloning into pmg36e. when introduced into e. coli, the recombinant plasmid expresse ... | 1993 | 8510661 |
| chromosome mapping in lactic acid bacteria. | the chromosome structure of lactic acid bacteria has been investigated only recently. the development of pulsed-field gel electrophoresis (pfge) combined with other dna-based techniques enables whole-genome analysis of any bacterium, and has allowed rapid progress to be made in the knowledge of the lactic acid bacteria genome. lactic acid bacteria possess one of the smallest eubacterial chromosomes. depending on the species, the genome sizes range from 1.1 to 2.6 mb. combined physical and geneti ... | 1993 | 14735909 |
| intrageneric conjugal transfer of lactose plasmid dna in lactococcus lactis subsp. lactis niai 527. | 1993 | 27316900 | |
| conservation of a transcription antitermination mechanism in aminoacyl-trna synthetase and amino acid biosynthesis genes in gram-positive bacteria. | most of the aminoacyl-trna synthetase genes identified to date in the gram-positive bacterium bacillus subtilis have been found to be regulated by readthrough of a transcriptional terminator located in the mrna leader region, upstream of the start of the coding sequence. all of these leader regions contain a series of conserved structural features, as well as a single codon displayed at a precise position within the structure, which has been shown for tyrs to be responsible for the specificity o ... | 1994 | 8289305 |
| characterization of is905, a new multicopy insertion sequence identified in lactococci. | is905 is a multicopy insertion sequence identified in lactococcus lactis. it is 1313 bp long, bounded by 28-bp imperfect inverted repeats, and encodes a putative transposase of 391 amino acids. one end of is905 contains sequences that are potentially promoter active. it displays sequence homology to the is256 class of elements. | 1994 | 8195098 |
| identification of a novel cell wall-associated endopeptidase in lactococcus lactis subspecies cremoris sk11. | 1994 | 8206261 | |
| 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 |
| inhibition of the phosphoenolpyruvate:lactose phosphotransferase system and activation of a cytoplasmic sugar-phosphate phosphatase in lactococcus lactis by atp-dependent metabolite-activated phosphorylation of serine 46 in the phosphocarrier protein hpr. | lactococcus lactis takes up lactose and the nonmetabolizable lactose analogue, thiomethyl-beta-galactoside (tmg), via the phosphoenolpyruvate:sugar phosphotransferase system (pts) which couples sugar transport to sugar phosphorylation. earlier studies had shown that tmg-phosphate, previously accumulated in l. lactis cells, is rapidly dephosphorylated in the cytoplasm and effluxes from the cells upon addition of glucose and that glucose inhibits further uptake of tmg. we have developed a vesicula ... | 1994 | 8163482 |
| a variant of the staphylococcal chloramphenicol resistance plasmid pc194 with enhanced ability to transform lactococcus lactis subsp. lactis. | in our attempts to transform lactococcus lactis subsp. lactis with pc194, a staphylococcal chloramphenicol resistance plasmid, only a few transformants could be obtained and only when relatively large amounts of plasmid dna were used. however, when pc194 dna from lactococcal transformants was introduced back to staphylococcus aureus and reisolated, it could be retransformed into l. lactis at substantially higher frequencies. it was concluded that pc194 had undergone mutation expanding its host r ... | 1994 | 8171121 |
| application of the ligase chain reaction to the detection of nisina and nisinz genes in lactococcus lactis ssp. lactis. | this paper reports on the application of the ligase chain reaction (lcr) to the specific detection of variants of the nisin structural gene (nisina and nisinz) in nisin producing strains of lactococcus lactis ssp lactis. the lcr assay was used to screen nisin producing strains to determine which form of the nisin structural gene they contained. this method of differentiating the nisin structural gene variants provides a useful alternative to the only other available genetic differentiation, that ... | 1994 | 8181709 |
| cloning and sequencing of the lactococcus lactis subsp. lactis dnak gene using a pcr-based approach. | the coding region for the dnak gene from lactococcus lactis subsp. lactis lm0230 was isolated and sequenced. an internal 789-bp fragment was amplified by the polymerase chain reaction (pcr) using a pair of degenerate oligodeoxyribonucleotide primers designed on the basis of amino acid (aa) sequences conserved in a number of dnak. this pcr product was cloned, sequenced and used as a southern hybridization probe to locate the flanking regions of the gene. the sequence of this central region from d ... | 1994 | 8181763 |
| the di- and tripeptide transport protein of lactococcus lactis. a new type of bacterial peptide transporter. | lactococcus lactis takes up di- and tripeptides via a proton motive force-dependent carrier protein. the gene (dtpt) encoding the di-tripeptide transport protein of l. lactis was cloned by complementation of a dipeptide transport-deficient and proline auxotrophic escherichia coli strain. functional expression of the dipeptide transport gene was demonstrated by uptake studies of alanyl-[14c]glutamate and other peptides in e. coli cells. the di-tripeptide transport protein catalyzes proton motive ... | 1994 | 8157671 |
| specificity of hydrolysis of bovine kappa-casein by cell envelope-associated proteinases from lactococcus lactis strains. | the cell envelope-associated proteinases from lactococcus lactis subsp. cremoris h2 (a pi-type proteinase-producing strain) and sk11 (a piii-type proteinase-producing strain) both actively hydrolyze the kappa-casein component of bovine milk but with significant differences in the specificity of peptide bond hydrolysis. the peptide bonds ala-23-lys-24, leu-32-ser-33, ala-71-gln-72, leu-79-ser-80, met-95-ala-96, and met-106-ala-107 were cleaved by both proteinase types, although the relative rates ... | 1994 | 8161175 |
| regulation of nisin biosynthesis and immunity in lactococcus lactis 6f3. | the biosynthetic genes of the nisin-producing strain lactococcus lactis 6f3 are organized in an operon-like structure starting with the structural gene nisa followed by the genes nisb, nist, and nisc, which are probably involved in chemical modification and secretion of the prepeptide (g. engelke, z. gutowski-eckel, m. hammelmann, and k.-d. entian, appl. environ. microbiol. 58:3730-3743, 1992). subcloning of an adjacent 5-kb downstream region revealed additional genes involved in nisin biosynthe ... | 1994 | 8161176 |
| 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 |
| identification and characterization of genes involved in excision of the lactococcus lactis conjugative transposon tn5276. | the 70-kb transposon tn5276, originally detected in lactococcus lactis nizo r5 and carrying the genes for nisin production and sucrose fermentation, can be conjugally transferred to other l. lactis strains. sequence analysis and complementation studies showed that the right end of tn5276 contains two genes, designated xis and int, which are involved in excision. the 379-amino-acid int gene product shows high (up to 50%) similarity with various integrases, including that of the tn916-related conj ... | 1994 | 8157585 |
| 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 |
| tripeptidase gene (pept) of lactococcus lactis: molecular cloning and nucleotide sequencing of pept and construction of a chromosomal deletion mutant. | the gene encoding a tripeptidase (pept) of lactococcus lactis subsp. cremoris (formerly subsp. lactis) mg1363 was cloned from a genomic library in puc19 and subsequently sequenced. the tripeptidase of l. lactis was shown to be homologous to pept of salmonella typhimurium with 47.4% identity in the deduced amino acid sequences. l. lactis pept was enzymatically active in escherichia coli and allowed growth of a peptidase-negative leucine-auxotrophic e. coli strain by liberation of leu from a tripe ... | 1994 | 8188586 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |