Publications

ctsr of lactococcus lactis encodes a negative regulator of clp gene expression.	bacteria undergo a complex programme of differential gene expression in response to stress. in bacillus subtilis, it was recently shown that ctsr, a negative transcriptional regulator, mediates stress-induced expression of components of the clp protease complex. in this study, a gene was identified in the gram-positive bacterium lactococcus lactis that encodes a 17 kda product with 38% identity to the ctsr protein of b. subtilis. by northern analyses it was found that in a l. lactis strain carry ...	2000	10846223
pharmacokinetics of lactobacillus plantarum ncimb 8826, lactobacillus fermentum kld, and lactococcus lactis mg 1363 in the human gastrointestinal tract.	genetically modified lactic acid bacteria may be a way to deliver vaccinal epitopes in the gastrointestinal tract.	2000	10848668
metabolic characterization of lactococcus lactis deficient in lactate dehydrogenase using in vivo 13c-nmr.	the metabolism of glucose by nongrowing cells of lactococcus lactis strain fi7851, constructed from the wild-type l. lactis strain mg1363 by disruption of the lactate dehydrogenase (ldh) gene [gasson, m.j., benson, k., swindel, s. & griffin, h. (1996) lait 76, 33-40] was studied in a noninvasive manner by 13c-nmr. the kinetics of the build-up and consumption of the pools of intracellular intermediates mannitol 1-phosphate, fructose 1,6-bisphosphate, 3-phosphoglycerate, and phosphoenolpyruvate as ...	2000	10849005
the neprilysin family in health and disease.	the mammalian neprilysin (nep) family comprises at least seven members: nep itself, kell blood group antigen (kell), the endothelin-converting enzymes (ece-1 and ece-2), the enzyme pex, associated with x-linked hypophosphataemia, "x-converting enzyme" (xce) a cns-expressed orphan peptidase and a soluble, secreted endopeptidase (sep). these zinc metallopeptidases are all type ii integral membrane proteins. where identified, these enzymes have roles in the processing or metabolism of regulatory pe ...	2000	10849750
effect of carbon dioxide under high pressure on the survival of cheese starter cultures.	a new processing method that rapidly forms curds and whey from milk has the potential to improve cheesemaking procedures if cheese starter cultures can tolerate the processing conditions. the survival of lactobacillus delbrueckii ssp. bulgaricus, lactococcus lactis ssp. lactis, or streptococcus thermophilus through this new process was evaluated. inoculated milk containing 0, 1, or 3.25% fat or lactobacillus mrs broth or tryptone yeast lactose broth (depending on microorganism used) was sparged ...	2000	10852570
abc transporters in lipid transport.	since it was found that the p-glycoproteins encoded by the mdr3 (mdr2) gene in humans and the mdr2 gene in mice are primarily phosphatidylcholine translocators, there has been increasing interest in the possibility that other atp binding cassette (abc) transporters are involved in lipid transport. the evidence reviewed here shows that the mdr1 p-glycoprotein and the multidrug resistance (-associated) transporter 1 (mrp1) are able to transport lipid analogues, but probably not major natural membr ...	2000	10856718
genetic locus for streptolysin s production by group a streptococcus.	group a streptococcus (gas) is an important human pathogen that causes pharyngitis and invasive infections, including necrotizing fasciitis. streptolysin s (sls) is the cytolytic factor that creates the zone of beta-hemolysis surrounding gas colonies grown on blood agar. we recently reported the discovery of a potential genetic determinant involved in sls production, saga, encoding a small peptide of 53 amino acids (s. d. betschel, s. m. borgia, n. l. barg, d. e. low, and j. c. de azavedo, infec ...	2000	10858242
osmoregulated abc-transport system of lactococcus lactis senses water stress via changes in the physical state of the membrane.	an osmoregulated abc transporter (opua) with novel structural features has been identified that responds to water stress. this glycine betaine transport system consists of an atp-binding/hydrolyzing subunit (opuaa) and a protein (opuabc) that contains both the translocator and the substrate-binding domain. the components of opua have been overexpressed, purified, and functionally incorporated into liposomes with an atp-regenerating system in the vesicle lumen. a transmembrane osmotic gradient (o ...	2000	10860977
solution properties of viilian, the exopolysaccharide from lactococcus lactis subsp. cremoris sbt 0495.	the exopolysaccharide (eps) "viilian" was isolated from a large-batch fermentation of lactococcus lactis subsp. cremoris sbt 0495. after applying a newly developed purification procedure, pure viilian with a weight-averaged molar mass of 2.64 x 10(3) kg/mol was obtained in a yield of 0.6 g/l culture broth. the native eps, as well as lower molar mass fractions obtained by sonication of the native polymer, were studied by capillary viscometry and size-exclusion chromatography (sec) coupled to mult ...	2000	10861375
isothiocyanates in myrosinase treated herb extract of cleome chrysantha decne. and their antimicrobial activities.	gc/ms analysis of the volatiles produced by the action of endogenous myrosinase in cleome chrysantha decne. herb, showed three major components, 1-isocyano-4-methyl benzene, gamma-muurolene and (cis) nerolidole (21.72%, 12.15% and 10.39%, respectively). 1-isocyano-4-methyl benzene is not produced from myrosinase treated seeds of cleome chrysantha decne., while muurolene and nerolidole were found at higher concentrations 16.1% and 13.67%, respectively. some other isothiocyanates identified in the ...	2000	10861975
lactic acid bacteria as a cell factory: rerouting of carbon metabolism in lactococcus lactis by metabolic engineering.	lactic acid bacteria display a relatively simple metabolism wherein the sugar is converted mainly to lactic acid. the extensive knowledge of metabolic pathways and the increasing information of the genes involved allows for the rerouting of natural metabolic pathways by genetic and physiological engineering. we discuss several examples of metabolic engineering of lactococcus lactis for the production of important compounds, including diacetyl, alanine and exopolysaccharides.	2000	10862894
transcriptional control of the citrate-inducible citmcdefgrp operon, encoding genes involved in citrate fermentation in leuconostoc paramesenteroides.	in this study we describe the expression pattern of the leuconostoc paramesenteroides citmcdefgrp operon in response to the addition of citrate to the growth medium. an 8.8-kb polycistronic transcript, which includes the citmcdefgrp genes, was identified; its synthesis was dramatically induced upon addition of citrate to the growth medium. we also found that expression of the cit operon is subjected to posttranscriptional regulation, since processing sites included in four complex secondary stru ...	2000	10869065
catalytic properties of dihydroorotate dehydrogenase from saccharomyces cerevisiae: studies on ph, alternate substrates, and inhibitors.	yeast dihydroorotate dehydrogenase (dhod) was purified 2800-fold to homogeneity from its natural source. its sequence is 70% identical to that of the lactococcus lactis dhod (family ia) and the two active sites are nearly the same. incubations of the yeast dhod with dideuterodihydroorotate (deuterated in the positions eliminated in the dehydrogenation) as the donor and [14c]orotate as the acceptor revealed that the c5 deuteron exchanged with h2o solvent at a rate equal to the 14c exchange rate, ...	2000	10871048
rapid genome walking: a simplified oligo-cassette mediated polymerase chain reaction using a single genome-specific primer.	in the present report we show that unknown dna fragments are easily amplified in a single pcr reaction from an oligo-cassette library with a single genome-specific primer in combination with a cassette-specific primer. the novelty of the system, in comparison to the vectorette pcr method, lies in the use of unphosphorylated in contrast with phosphorylated oligo-cassettes in the ligation to the chromosomal dna fragments. after denaturation of the dna library, all chromosomal fragments carry a sin ...	2000	10871354
use of hydrolyzed whey peptide to inhibit culture agglutination.	papain was used to hydrolyze sweet whey to prepare peptides that were harvested with ultrafiltration membranes (molecular weight cutoffs of 10,000, 3000, and 1000). insure buffer salts were added to whey peptides (ratio 40:60% solids, respectively) to prepare media that were tested for their ability to inhibit culture agglutination. commercial insure medium (75.7 g/l) was used as a control. skim milk (240 ml) in 250-ml graduated cylinders was inoculated (4%) with lactococcus lactis spp. lactis b ...	2000	10877383
deletion of various carboxy-terminal domains of lactococcus lactis sk11 proteinase: effects on activity, specificity, and stability of the truncated enzyme.	the lactococcus lactis sk11 cell envelope proteinase is an extracellular, multidomain protein of nearly 2,000 residues consisting of an n-terminal serine protease domain, followed by various other domains of largely unknown function. using a strategy of deletion mutagenesis, we have analyzed the function of several c-terminal domains of the sk11 proteinase which are absent in cell envelope proteinases of other lactic acid bacteria. the various deletion mutants were functionally expressed in l. l ...	2000	10877779
gene cloning and expression and secretion of listeria monocytogenes bacteriophage-lytic enzymes in lactococcus lactis.	bacteriophage lysins (ply), or endolysins, are phage-encoded cell wall lytic enzymes which are synthesized late during virus multiplication and mediate the release of progeny virions. bacteriophages of the pathogen listeria monocytogenes encode endolysin enzymes which specifically hydrolyze the cross-linking peptide bridges in listeria peptidoglycan. ply118 is a 30.8-kda l-alanoyl-d-glutamate peptidase and ply511 (36.5 kda) acts as n-acetylmuramoyl-l-alanine amidase. in order to establish dairy ...	2000	10877791
thrombocidins, microbicidal proteins from human blood platelets, are c-terminal deletion products of cxc chemokines.	antibacterial proteins are components of the innate immune system found in many organisms and produced by a variety of cell types. human blood platelets contain a number of antibacterial proteins in their alpha-granules that are released upon thrombin activation. the present study was designed to purify these proteins obtained from human platelets and to characterize them chemically and biologically. two antibacterial proteins were purified from platelet granules in a two-step protocol using cat ...	2000	10877842
[cloning and expression of human cu/zn superoxide dismutase gene in lactococcus lactis].	the cdna encoding human cu/zn sod was amplified by rt-pcr using the total rna of human liver as the template, and was cloned into an e. coli expression vector pet23b. after the dna sequence was determined, the recombinant plasmid pet23bsod was introduced into e. coli bl21(de3)/plyss. sds-page analysis revealed that the recombinant e. coli expressed the predicted 19 kda human cu/zn sod, and its amount was over 50% of total proteins. the cu/zn sod cdna was then subcloned into a lactococcal express ...	2000	10883266
orientation specificity of the lactococcus lactis chi site.	in escherichia coli, the chi sequence modulates the activity of recbcd, a powerful double-stranded (ds) dna exonuclease/helicase. chi attenuates recbcd exonuclease activity and stimulates homologous recombination in an orientation-dependent manner. chiec is frequent and over-represented on its genome, which is thought to be related to its role in dsdna break repair. we previously identified a chi-like sequence (referred to as chill) and an exonuclease/helicase in the gram-positive bacterium lact ...	2000	10886371
evaluation of solid-phase microextraction for the isotopic analysis of volatile compounds produced during fermentation by lactic acid bacteria.	the use of solid-phase microextraction (spme) coupled with isotope ratio mass spectrometry (irms) for the analysis of flavor compounds produced by lactic acid bacteria has been evaluated using both liquid and headspace sampling modes. initially, it was necessary to optimize the conditions for the spme extraction of flavors-diacetyl and acetoin-in standard aqueous solutions. the effects of salt, headspace versus liquid sampling, and coating phase were tested. second, the suitability of the coupli ...	2000	10888526
human glutathione-s-transferase: cloning and expression in lactococcus lactis.	the glutathione-s-transferase a1 cdna was amplified from the total rnas of human liver by rt-pcr, and inserted into plasmid pmg36e. the hgsta1 was expressed in lactococcus lactis mg1363 and verified by sds-page and western blot, purified by affinity chromatography and showed enzymatic activity.	2000	10894115
analysis of promoter sequences from lactobacillus and lactococcus and their activity in several lactobacillus species.	promoter-active fragments were isolated from the genome of the probiotic organism lactobacillus rhamnosus strain gg using the promoter-probe vector pnz272. these promoter elements, together with a promoter fragment isolated from the vaginal strain lactobacillus fermentum br11 and two previously defined promoters (lactococcus lactis and lactobacillus acidophilus atcc 4356 slpa), were introduced into three strains of lactobacillus. primer-extension analysis was used to map the transcriptional star ...	2000	10896218
on the binding mechanism of the peptide receptor of the oligopeptide transport system of lactococcus lactis.	lactococcus lactis degrades exogenous proteins such as beta-casein to peptides of 4-30 amino acids, and uses these as nitrogen sources. the binding protein or receptor (oppa(ll)) of the oligopeptide transport system (opp) of l.lactis: has the unique capacity to bind peptides from five up to at least 20 residues. to study the binding mechanism of oppa(ll), nonameric peptides were used in which the cysteine at position 1, 3, 4, 5, 6, 7 or 9 was selectively labeled with either bulky and non-fluores ...	2000	10899119
differential protein expression in phenotypic variants of streptococcus pneumoniae.	streptococcus pneumoniae undergoes spontaneous phase variation resulting in opaque and transparent colony forms. differences in colony opacity correlate with differences in virulence: the transparent variants are more capable of colonizing the nasopharynx, whereas the opaque variants show increased virulence during systemic infections. to gain insight into the pathogenesis of pneumococcal disease at the molecular level, protein expression patterns of the phenotypic variants of two pneumococcal s ...	2000	10899862
identification of saliva-regulated genes of streptococcus gordonii dl1 by differential display using random arbitrarily primed pcr.	attachment of streptococcus gordonii to the acquired pellicle of the tooth surface involves specific interactions between bacterial adhesins and adsorbed salivary components. to study saliva-regulated gene expression in s. gordonii, we used random arbitrarily primed pcr (rap-pcr). bacteria were incubated in either brain heart infusion medium or saliva. total rna from both conditions was purified and rap fingerprinted and then pcr amplified with an arbitrary primer. the differentially displayed d ...	2000	10899901
pulmonary pathology of harbour porpoises (phocoena phocoena) stranded in england and wales between 1990 and 1996.	the pathological changes observed in the lungs of 197 freshly dead to moderately decomposed harbour porpoises (phocoenaphocoena) stranded in england and wales between october 1990 and december 1996 were reviewed. in 135 (69 per cent of the cases) macroscopic nematode infections of the bronchial tract with pseudalius inflexus and torynurus convolutus, either singly or in combination, were recorded, and 106 (54 per cent) also had p inflexus within the pulmonary blood vessels. all the macroscopical ...	2000	10901214
group ii introns designed to insert into therapeutically relevant dna target sites in human cells.	mobile group ii intron rnas insert directly into dna target sites and are then reverse-transcribed into genomic dna by the associated intron-encoded protein. target site recognition involves modifiable base-pairing interactions between the intron rna and a >14-nucleotide region of the dna target site, as well as fixed interactions between the protein and flanking regions. here, we developed a highly efficient escherichia coli genetic assay to determine detailed target site recognition rules for ...	2000	10903206
engineering the active center of the 6-phospho-beta-galactosidase from lactococcus lactis.	several amino acids in the active center of the 6-phospho-beta-galactosidase from lactococcus lactis were replaced by the corresponding residues in homologous enzymes of glycosidase family 1 with different specificities. three mutants, w429a, k435v/y437f and s428d/ k435v/y437f, were constructed. w429a was found to have an improved specificity for glucosides compared with the wild-type, consistent with the theory that the amino acid at this position is relevant for the distinction between galacto ...	2000	10906347
short communication: salt extends the upper temperature limit for growth of lactococcus lactis ssp. cremoris on solid m17 medium.	we have determined conditions for plating of the lactococcus lactis ssp. cremoris laboratory strain mg1363 on solid m17 broth at 38 degrees c, which is required for the optimal use of the pghost plasmids. the addition of 1% nacl (or kcl, potassium acetate, or sucrose at 170 mm) to m17 agar plates results in extension of the upper temperature limit for growth from 37 to 40 degrees c; no decrease in plating efficiency was detected from 30 to 39 degrees c.	2000	10908051
inactivation of the stress- and starvation-inducible gls24 operon has a pleiotrophic effect on cell morphology, stress sensitivity, and gene expression in enterococcus faecalis.	enterococcus faecalis induces the synthesis of at least 42 proteins during 24 h of glucose starvation. because of its induction during carbohydrate and complete starvation (incubation in tap water) and cdcl(2) and bile salts stresses, one of these proteins (gls24) was qualified as a "general stress protein" and was analyzed at the molecular level. its corresponding gene, gls24, seems to be the penultimate gene of an operon composed, altogether, of six open reading frames (orfs). the orf precedin ...	2000	10913085
behavior of listeria monocytogenes in pasteurized milk during fermentation with lactic acid bacteria.	the behavior of listeria monocytogenes in pasteurized milk during fermentation with starter and nonstarter lactic acid bacteria was investigated. pasteurized milk was co-inoculated with approximately 10(4) cfu/ml of l. monocytogenes and 10(6) cfu/ml of lactococcus lactis, lactococcus cremoris, lactobacillus plantarum, lactobacillus bulgaricus, or streptococcus thermophilus. inoculated milks were incubated at 30 degrees c or 37 degrees c for 24 to 72 h. listeria monocytogenes survived and also gr ...	2000	10914660
characterization of the cryptic plasmid psbo2 isolated from streptococcus bovis jb1 and construction of a new shuttle vector.	a cryptic plasmid designated psbo2 (3582 bp) was isolated from streptococcus bovis jb1. the psbo2 contained putative sites for a double-strand origin (dso), a small transcriptional repressor protein (cop), countertranscribed rnas (ctrnas), and a replication protein (rep), which were similar to those from pmv158 and pls1, which were isolated from s. agalactiae, and pwvo1, isolated from lactococcus lactis. the putative single-strand origin (sso) of psbo2 was similar to per341 and pst1, which were ...	2000	10919395
requirement of autolytic activity for bacteriocin-induced lysis.	the bacteriocin produced by lactococcus lactis ifpl105 is bactericidal against several lactococcus and lactobacillus strains. addition of the bacteriocin to exponential-growth-phase cells resulted in all cases in bacteriolysis. the bacteriolytic response of the strains was not related to differences in sensitivity to the bacteriocin and was strongly reduced in the presence of autolysin inhibitors (co(2+) and sodium dodecyl sulfate). when l. lactis mg1363 and its derivative deficient in the produ ...	2000	10919766
heterologous coproduction of enterocin a and pediocin pa-1 by lactococcus lactis: detection by specific peptide-directed antibodies.	antibodies against enterocin a were obtained by immunization of rabbits with synthetic peptides ph4 and ph5 designed, respectively, on the n- and c-terminal amino acid sequences of enterocin a and conjugated to the carrier protein klh. anti-ph4-klh antibodies not only recognized enterocin a but also pediocin pa-1, enterocin p, and sakacin a, three bacteriocins which share the n-terminal class iia consensus motif (ygngvxc) that is contained in the sequence of the peptide ph4. in contrast, anti-ph ...	2000	10919819
propionicin sm1, a bacteriocin from propionibacterium jensenii df1: isolation and characterization of the protein and its gene.	we purified a bacteriocin from the cell-free supernatant of propionibacterium jensenii df1 isolated from swiss raw milk, and named it propionicin sm1. the heat-stable protein was strongly bactericidal against p. jensenii dsm20274. on the basis of the n-terminal amino acid sequence of the purified protein, a degenerate oligonucleotide probe was designed to locate and clone the corresponding gene of p. jensenii df1. it hybridized exclusively with the df1l-resident plasmid plme106, but not with chr ...	2000	10930068
regulation of intron function: efficient splicing in vivo of a bacterial group ii intron requires a functional promoter within the intron.	conjugative transfer of the lactococcus lactis plasmid prs01 requires splicing of a group ii intron, ll.ltrb, for accurate translation of the mrna for the exon gene ltrb. the protein product of ltrb is a conjugative relaxase, essential for prs01 transfer. using a molecular technique for the identification of transcription initiation sites in bacteria, a functional promoter within ll.ltrb was identified upstream from the gene for the intron-encoded protein (iep) ltra. ltra is required for efficie ...	2000	10931357
glucose/citrate cometabolism in lactococcus lactis subsp. lactis biovar diacetylactis with impaired alpha-acetolactate decarboxylase.	the pyruvate metabolism of a lactococcus lactis subsp. lactis biovar diacetylactis mutant deficient in alpha-acetolactate decarboxylase and its wild-type strain was studied during batch cultivations. a chemically defined medium was used containing glucose as carbon- and energy-source. the alpha-acetolactate decarboxylase deficiency had no effect on the specific growth rate. addition of citrate was found to increase the specific growth rate of both strains under aerobic and anaerobic conditions. ...	1999	10937822
pyruvate metabolism in lactococcus lactis is dependent upon glyceraldehyde-3-phosphate dehydrogenase activity.	modification of glyceraldehyde-3-phosphate dehydrogenase (gapdh) activity from lactococcus lactis was undertaken during batch fermentation on lactose, by adding various concentrations of iodoacetate (iaa), a compound which specifically inhibits gapdh at low concentrations, to the culture medium. as iaa concentration is increased, gapdh activity diminishes, provoking a decrease of both the glycolytic flux and the specific growth rate. this control exerted at the level of gapdh was due partially t ...	1999	10937934
characterization of opua, a glycine-betaine uptake system of lactococcus lactis.	a lactococcus lactis glycine-betaine transport system was identified by functional complementation of an escherichia coli prop prou mutant with a gene library from l. lactis sbsp. cremoris. the cloned locus forms an operon highly homologous to opua, encoding a glycine-betaine uptake system of bacillus subtilis. disruption of opua in l. lactis abolished protection by glycine-betaine against elevated osmolarity. opua belongs to the so-called "abc transporters" family, which comprise an extracellul ...	2000	10939245
towards a proteomic map of lactococcus lactis ncdo 763.	lactococcus lactis is a widely used bacteria in dairy industry, specially in cheese ripening. numerous lactococcal enzymes and proteins are involved in this process. proteomics makes it possible to deal with a high number of proteins and identify modification of their patterns in two-dimensional (2-d) gels. however, an annotated reference map is necessary prior to analyzing protein variations. we have begun to construct such a map in easily reproducible conditions and identify proteins.	2000	10939470
the membrane-bound h(+)-atpase complex is essential for growth of lactococcus lactis.	the eight genes which encode the (f(1)f(o)) h(+)-atpase in lactococcus lactis subsp. cremoris mg1363 were cloned and sequenced. the genes were organized in an operon with the gene order atpebfhagdc; i.e., the order of atpe and atpb is reversed with respect to the more typical bacterial organization. the deduced amino acid sequences of the corresponding h(+)-atpase subunits showed significant homology with the subunits from other organisms. results of northern blot analysis showed a transcript at ...	2000	10940012
synthesis and posttranslational regulation of pyruvate formate-lyase in lactococcus lactis.	the enzyme pyruvate formate-lyase (pfl) from lactococcus lactis was produced in escherichia coli and purified to obtain anti-pfl antibodies that were shown to be specific for l. lactis pfl. it was demonstrated that activated l. lactis pfl was sensitive to oxygen, as in e. coli, resulting in the cleavage of the pfl polypeptide. the pfl protein level and its in vivo activity and regulation were shown by western blotting, enzyme-linked immunosorbent assay, and metabolite measurement to be dependent ...	2000	10940018
the role of escherichia coli rnase e and rnase iii in the processing of the citqrp operon mrna from lactococcus lactis biovar diacetylactis.	citrate transport in lactococcus lactis biovar diacetylactis (l. diacetylactis) is catalyzed by citrate permease p (citp), which is encoded by the plasmidic citp gene. two partial overlapping open reading frames citq and citr are located upstream of citp. these two genes, together with citp, constitute the citqrpoperon. in this report it was shown that in l. diacetylactis and escherichia coli, cit mrna is subject to the same specific cleavages at a complex secondary structure which includes the ...	1999	10943565
influence of different substrate limitations on the yield, composition and molecular mass of exopolysaccharides produced by lactococcus lactis subsp. cremoris in continuous cultures.	the type of substrate limitation had a remarkable influence on the molecular mass of exopolysaccharides (eps) produced by lactococcus lactis subsp. cremoris nizo b40 and nizo b891. under glucose/energy limitation, the molecular mass was much smaller than under leucine or phosphate limitation, resulting in a marked decrease of the intrinsic viscosity of this eps. the sugar composition of eps produced by both strains, and the phosphate content of eps produced by nizo b40, were not affected by the ...	2000	10945787
effects of lactobacillus strains on the ripening and organoleptic characteristics of arzúa-ulloa cheese.	seven batches of arzúa-ulloa, a short-ripened soft cow's milk cheese produced in galicia (nw spain), were prepared from pasteurized milk. two control batches of cheese (cb) were made with an acid-aromatic starter containing lactococcus lactis subsp. lactis and lactococcus lactis subsp. lactis var. diacetylactis, isolated from raw-milk arzúa-ulloa cheeses. five batches of cheese (lb) were made with the acid-aromatic starter plus one of five strains of mesophilic homofermentative lactobacillus spp ...	2000	10946837
dihydroorotate dehydrogenase from clostridium oroticum is a class 1b enzyme and utilizes a concerted mechanism of catalysis.	dihydroorotate dehydrogenase from clostridium oroticum was purified to apparent homogeneity and found to be a heterotetramer consisting of two alpha (32 kda) and two beta (28 kda) polypeptides. this subunit composition, coupled with known cofactor requirements and the ability to transfer electrons from l-dihydroorotate to nad(+), defines the c. oroticum enzyme as a family 1b dihydroorotate dehydrogenase. the results of steady-state kinetic analyses and isotope exchange studies suggest that this ...	2000	10956027
treatment of murine colitis by lactococcus lactis secreting interleukin-10.	the cytokine interleukin-10 (il-10) has shown promise in clinical trials for treatment of inflammatory bowel disease (ibd). using two mouse models, we show that the therapeutic dose of il-10 can be reduced by localized delivery of a bacterium genetically engineered to secrete the cytokine. intragastric administration of il-10-secreting lactococcus lactis caused a 50% reduction in colitis in mice treated with dextran sulfate sodium and prevented the onset of colitis in il-10(-/-) mice. this appro ...	2000	10958782
cholate resistance in lactococcus lactis is mediated by an atp-dependent multispecific organic anion transporter.	the cholate-resistant lactococcus lactis strain c41-2, derived from wild-type l. lactis mg1363 through selection for growth on cholate-containing medium, displayed a reduced accumulation of cholate due to an enhanced active efflux. however, l. lactis c41-2 was not cross resistant to deoxycholate or cationic drugs, such as ethidium and rhodamine 6g, which are typical substrates of the multidrug transporters lmrp and lmra in l. lactis mg1363. the cholate efflux activity in l. lactis c41-2 was not ...	2000	10960105
lantibiotic biosynthesis: interactions between prelacticin 481 and its putative modification enzyme, lctm.	class aii and aiii lantibiotics and mersacidin are antibacterial peptides containing unusual residues obtained by posttranslational modifications of prepeptides, presumably catalyzed by lanm. lctm, the lanm for lacticin 481, is essential for the production of this class aii lantibiotic. using the yeast two-hybrid system, we showed direct contact between the prelacticin 481 and lctm, supporting the proposed lctm function. sixteen domains are conserved between the 10 known lanm proteins, whereas t ...	2000	10960114
improved vectors for nisin-controlled expression in gram-positive bacteria.	a set of shuttle vectors, able to replicate in escherichia coli and in gram-positive bacteria, containing a nisin-inducible promoter (pnisa) and genes encoding nisr and nisk, the two-component signaling mechanism for activating transcription from pnisa in the presence of nisin, was constructed. to test these vectors, enterococcus faecalis pcf10 plasmid genes prgx, prgy, and prgz, which respectively encode cytosolic, integral membrane, and cell surface proteins, were cloned downstream of pnisa. i ...	2000	10964628
characterization of a novel plasmid-encoded hsds subunit, s.llaw12i, from lactococcus lactis w12.	a novel type i restriction-modification specificity subunit, s. llaw12i, has been identified on the naturally occurring 8.0-kb plasmid paw122 in the lactic acid bacterium lactococcus lactis subsp. cremoris w12. presence of the hsds protein together with a complete type i restriction-modification system conferred increased phage restriction to the host, indicating exchange of specificity subunits. sequence analysis showed that the s.llaw12i subunit is most probably of type ic. presumably, the hsd ...	2000	10964630
changes in glycolytic activity of lactococcus lactis induced by low temperature.	the effects of low-temperature stress on the glycolytic activity of the lactic acid bacterium lactococcus lactis were studied. the maximal glycolytic activity measured at 30 degrees c increased approximately 2.5-fold following a shift from 30 to 10 degrees c for 4 h in a process that required protein synthesis. analysis of cold adaptation of strains with genes involved in sugar metabolism disrupted showed that both the phosphoenolpyruvate-dependent sugar phosphotransferase system (pts) subunit h ...	2000	10966377
physiological and regulatory effects of controlled overproduction of five cold shock proteins of lactococcus lactis mg1363.	the physiological and regulatory effects of overproduction of five cold shock proteins (csps) of lactococcus lactis were studied. cspb, cspd, and cspe could be overproduced at high levels (up to 19% of the total protein), whereas for cspa and cspc limited overproduction (0.3 to 0.5% of the total protein) was obtained. northern blot analysis revealed low abundance of the cspc transcript, indicating that the stability of cspc mrna is low. the limited overproduction of cspa is likely to be caused b ...	2000	10966387
production of angiotensin-i-converting-enzyme-inhibitory peptides in fermented milks started by lactobacillus delbrueckii subsp. bulgaricus ss1 and lactococcus lactis subsp. cremoris ft4.	two fermented milks containing angiotensin-i-converting-enzyme (ace)-inhibitory peptides were produced by using selected lactobacillus delbrueckii subsp. bulgaricus ss1 and l. lactis subsp. cremoris ft4. the ph 4.6-soluble nitrogen fraction of the two fermented milks was fractionated by reversed-phase fast-protein liquid chromatography. the fractions which showed the highest ace-inhibitory indexes were further purified, and the related peptides were sequenced by tandem fast atom bombardment-mass ...	2000	10966406
dissolution of xylose metabolism in lactococcus lactis.	xylose metabolism, a variable phenotype in strains of lactococcus lactis, was studied and evidence was obtained for the accumulation of mutations that inactivate the xyl operon. the xylose metabolism operon (xylrab) was sequenced from three strains of lactococci. fragments of 4.2, 4.2, and 5.4 kb that included the xyl locus were sequenced from l. lactis subsp. lactis b-4449 (formerly lactobacillus xylosus), l. lactis subsp. lactis io-1, and l. lactis subsp. lactis 210, respectively. the two envi ...	2000	10966417
lactococcus lactis as a cell factory for high-level diacetyl production.	we report the engineering of lactococcus lactis for the efficient conversion of sugar into diacetyl by combining nadh-oxidase overproduction and alpha-acetolactate decarboxylase inactivation. eighty percent of the carbon flux was found to be rerouted via alpha-acetolactate to the production of diacetyl by preloading the cells with nadh-oxidase before their use as a cell factory.	2000	10966436
modulation of humoral immune response through probiotic intake.	thirty healthy volunteers were randomised into three different treatment groups and consumed lactobacillus gg, lactococcus lactis or placebo (ethyl cellulose) for 7 days. on days 1, 3 and 5, an attenuated salmonella typhi ty21a oral vaccine was given to all subjects to mimic an enteropathogenic infection. all subjects responded well to the vaccine, but no significant differences were observed in numbers of iga-, igg- and igm-secreting cells among the different groups. there was a trend towards a ...	2000	10967260
genotypic and phenotypic heterogeneity among lactococci isolated from traditional pecorino sardo cheese.	twenty-nine lactococcus lactis isolates from one traditional 24 h-old pecorino sardo cheese were characterized phenotypically, technologically and genotypically in order to assess the biodiversity within this wild microbial population. two dna-based techniques, plasmid profiling and pfge, were used for the genetic typing of the isolates. all 29 isolates were characterized at strain level and eight different genotypes were recognized. in addition, by combining the results from plasmid profile ana ...	2000	10971750
biological and molecular characterization of a two-peptide lantibiotic produced by lactococcus lactis ifpl105.	the lactic acid bacterium lactococcus lactis ifpl105 secretes a broad spectrum bacteriocin produced from the 46 kb plasmid pbac105. the bacteriocin was purified to homogeneity by ionic and hydrophobic exchange and reverse-phase chromatography. bacteriocin activity required the complementary action of two distinct peptides (alpha and beta) with average molecular masses of 3322 and 2848 da, respectively. the genes encoding the two peptides were cloned and sequenced and were found to be identical t ...	2000	10971756
solvent extraction of bacteriocins from liquid cultures.	a solvent extraction method was developed to concentrate lacidin from the culture of lactobacillus acidophilus osu133. the new method concentrates the bacteriocin at the interface between chloroform and the aqueous culture of the producing bacterium. compared with other extraction procedures, the new method effectively recovers higher bacteriocin yield and results in relatively clean preparations. recovery of lacidin by the chloroform extraction procedure, compared with ammonium sulphate precipi ...	2000	10972727
regulation of growth inhibition at high temperature, autolysis, transformation and adherence in streptococcus pneumoniae by clpc.	the clpc atpase is a subfamily of hsp100/clp molecular chaperones-regulators of proteolysis. by screening a library of loss of function mutants for the ability to survive treatment with penicillin, we identified the gene clpc. the corresponding protein was identified as a clpc atpase, sharing strong peptide sequence identity with clpc of bacillus subtilis, listeria monocytogenes and lactococcus lactis. northern blot experiments showed that expression of clpc was induced in response to high tempe ...	2000	10972795
each peptide of the two-component lantibiotic lacticin 3147 requires a separate modification enzyme for activity.	the genetic determinants for production and immunity to the two-component lantibiotic lacticin 3147 are encoded by a 12.6 kb region of the plasmid pmrc01. this region contains ten genes arranged in two divergent clusters; these include the structural genes and a number of genes whose products show significant similarity to proteins involved in the biosynthesis of other lantibiotics. using a strategy of deletion and mutational analysis, the effect of disruption of a number of these genes was inve ...	2000	10974102
immunology. therapeutic manipulation of gut flora.	in developed countries as many as two individuals in every thousand suffer from inflammatory bowel disease (ulcerative colitis and crohn's disease). in his perspective, shanahan discusses a new therapeutic approach to treating these conditions in which bacteria normally found in the gut are engineered to produce the anti-inflammatory cytokine interleukin-10 and then are fed as probiotics to mice with these disorders (steidler et al.).	2000	10979858
efficacy of nisin-coated polymer films to inactivate salmonella typhimurium on fresh broiler skin.	nisin is an antimicrobial peptide produced by the food-grade microorganism lactococcus lactis subsp. lactis. this peptide inhibits many gram-positive bacteria, and when combined with chelating agents it inhibits gram-negative bacteria such as salmonella sp. the efficacy of packaging films treated with nisin-containing formulations to reduce salmonella contamination of fresh broiler drumstick skin and increase the refrigerated shelf life was investigated. three films (5.1 cm2) of varying hydropho ...	2000	10983791
transcriptional and translational regulation of alpha-acetolactate decarboxylase of lactococcus lactis subsp. lactis.	the alpha-acetolactate decarboxylase (aldc) gene, aldb, is the penultimate gene of the leu-ilv-ald operon, which encodes the three branched-chain amino acid (bcaa) biosynthesis genes in lactococcus lactis. its product plays a dual role in the cell: (i) it catalyzes the second step of the acetoin pathway, and (ii) it controls the pool of alpha-acetolactate during leucine and valine synthesis. it can be transcribed from the two promoters present upstream of the leu and ilv genes (p1 and p2) or ind ...	2000	10986242
is1675, a novel lactococcal insertion element, forms a transposon-like structure including the lacticin 481 lantibiotic operon.	two copies of is1675, a novel lactococcal insertion element from the is4 family, are present on a 70-kb plasmid, where they frame the lantibiotic lacticin 481 operon. the whole structure could be a composite transposon designated tn5721. this study shows that the lacticin 481 operon does not include any regulatory gene and provides a new example of a transposon-associated bacteriocin determinant. we identified five other is1675 copies not associated with the lacticin 481 operon. the conservation ...	2000	10986268
structural characterisation and enzymic modification of the exopolysaccharide produced by lactococcus lactis subsp. cremoris b891.	lactococcus lactis subsp. cremoris b891 grown on whey permeate produced an exopolysaccharide containing d-gal and d-glc in a molar ratio of 2:3. the polysaccharide was partially o-acetylated. by means of hf solvolysis, o-deacetylation, enzymic modification, sugar linkage analysis and id/2d nmr studies the exopolysaccharide was shown to be composed of repeating units with the following structure: [structure: see text].	2000	10990026
comparative genomics of the late gene cluster from lactobacillus phages.	three prophage sequences were identified in the lactobacillus johnsoni strain ncc533. prophage lj965 predicted a gene map very similar to those of pac-site streptococcus thermophilus phages over its dna packaging and head and tail morphogenesis modules. sequence similarity linked the putative dna packaging and head morphogenesis genes at the protein level. prophage lj965/s. thermophilus phage sfi11/lactococcus lactis phage tp901-1 on one hand and lactobacillus delbrueckii phage ll-h/lactobacillu ...	2000	10998330
viability of probiotic (bifidobacterium, lactobacillus acidophilus and lactobacillus casei) and nonprobiotic microflora in argentinian fresco cheese.	we evaluated the suitability of argentinian fresco cheese as a food carrier of probiotic cultures. we used cultures of bifidobacterium bifidum (two strains), bifidobacterium longum (two strains), bifidobacterium sp. (one strain), lactobacillus acidophilus (two strains), and lactobacillus casei (two strains) in different combinations, as probiotic adjuncts. probiotic, lactic starter (lactococcus lactis and streptococcus thermophilus), and contaminant (coliforms, yeasts, and molds) organisms were ...	2000	11003217
identification of a gene cluster encoding krebs cycle oxidative enzymes linked to the pyruvate carboxylase gene in lactococcus lactis ssp. lactis c2.	we identified a 14-kb pyruvate carboxylase gene-containing fragment from a lactococcal c2-lambda phage genomic library. downstream of the pyruvate carboxylase gene-containing fragment, a gene cluster coding for open reading frames displaying extensive homology to citrate synthase, aconitase, and a truncated isocitrate dehydrogenase was identified. however, the truncation was shown to have occurred during the cloning by two noncontiguous sau3ai fragments ligating together. the lactococcal citrate ...	2000	11003218
protection against staphylococcus aureus mastitis in dairy cows using a bismuth-based teat seal containing the bacteriocin, lacticin 3147.	we assessed the effectiveness of a novel dry cow treatment containing lacticin 3147 using deliberate challenge studies in lactating cows. infection-free quarters of lactating cows were infused with teat seal (cross vetpharm group, ltd., dublin, ireland) combined with the food-grade bacteriocin, lacticin 3147. natural infection of the teat was simulated by deliberately introducing staphylococcus aureus into the teat duct and teat sinus. relative to control quarters, teat seal plus lacticin 3147 r ...	2000	11003227
cloning, sequence analysis, and expression of lactobacillus casei phage pl-1 lysis genes.	the genes encoding the host cell wall-lytic proteins were searched in the genome dna of phage pl-1 active against lactobacillus casei atcc 27092 by comparing the amino acid sequences with those of others using a computer software of the ddbj data base. the gene regions found were cloned into e. coli by inserting pcr-amplified dna fragments into the ecori site of puc 19, and the nucleotide sequences were determined. one of the orfs (hol) consisted of 270 bp encoding 90 amino acids. the hol produc ...	2000	11003466
the n-terminal region of the oenococcus oeni bacteriophage fog44 lysin behaves as a bona fide signal peptide in escherichia coli and as a cis-inhibitory element, preventing lytic activity on oenococcal cells.	the function of the n-terminal region of the oenococcus oeni phage fog44 lysin (lys44) as an export signal was investigated. we observed that when induced in escherichia coli, lys44 was cleaved between residues 27 and 28 in a seca-dependent manner. lys44 processing could be blocked by a specific signal peptidase inhibitor and was severely reduced by modification of the cleavage site. the lethal effect of lys44 expression observed in e. coli was ascribed to the presence of its n-terminal 27-resid ...	2000	11004183
adaptation of the nisin-controlled expression system in lactobacillus plantarum: a tool to study in vivo biological effects.	the potential of lactic acid bacteria as live vehicles for the production and delivery of therapeutic molecules is being actively investigated today. for future applications it is essential to be able to establish dose-response curves for the targeted biological effect and thus to control the production of a heterologous biopeptide by a live lactobacillus. we therefore implemented in lactobacillus plantarum ncimb8826 the powerful nisin-controlled expression (nice) system based on the autoregulat ...	2000	11010894
development of bioactive food packaging materials using immobilised bacteriocins lacticin 3147 and nisaplin.	immobilisation of the bacteriocins nisin and lacticin 3147 to packaging materials was investigated. stability of both cellulose-based bioactive inserts and anti-microbial polyethylene/polyamide pouches was examined over time. anti-microbial activity against the indicator strain lactococcus lactis subsp. lactis hp, in addition to listeria innocua dpc 1770 and staphylococcus aureus mmpr3 was observed for all bacteriocin-adsorbed materials. activity retention of the inserts showed an initial decrea ...	2000	11016613
a simple and sensitive method to extract bacterial, yeast and fungal dna from blood culture material.	this study investigated the various commercially available kits and 'in-house' methods to extract dna from gram-negative and gram-positive bacteria, yeast and fungal agents in commonly employed blood culture material. the main methods investigated were as follows; qiagen qiamp blood kit, roche high pcr template preparation kit, puregene dna extraction kit, boiling, glass beads/sonication and wash/alkali/heat lysis. the results indicated that a simple wash/alkali/heat lysis method was the most se ...	2000	11018270
an evaluation of chelex-based dna purification protocols for the typing of lactic acid bacteria.	an easy and rapid protocol to extract dna to be used as template for polymerase chain reaction (pcr) fingerprinting experiments from cultivable lactic acid bacteria (lab) is proposed. different procedures for rapid extraction of dna by chelex (iminodiacetid acid) ionic resin were compared. factors affecting the quality and reproducibility of pcr fingerprinting profiles were also investigated. two out of three chelex-based protocols allowed to obtain dna samples which, after pcr amplification, pr ...	2000	11018274
effects of mixed starter composition on nisin z production by lactococcus lactis subsp. lactis biovar. diacetylactis ul 719 during production and ripening of gouda cheese.	a starter culture system that produced both acid and nisin at acceptable rates in milk for manufacture of gouda cheese was developed using nisin z-producing l. lactis subsp. lactis biovar. diacetylactis ul 719 (ul 719) and a commercial flora danica (fd) starter culture. different compositions of mixed cultures (0, 0.2, 0.4, 0.6 or 0.8% ul 719 with 1.4% fd) were tested for acidification and nisin z production in milk after 12 h incubation at 30 degrees c. the 0.6/1.4% combination, selected as the ...	2000	11020036
novel sucrose transposons from plant strains of lactococcus lactis.	lactococcus lactis strains isolated from vegetable products transferred the ability to ferment sucrose in conjugation experiments with the recipient strain l. lactis mg1614. nisin production and sucrose fermentation were transferred together from two strains, but transfer also occurred from several other strains which did not produce nisin. pulsed-field gel electrophoresis analysis showed that all transconjugants had acquired large chromosomal insertions at two main sites. nisin sucrose transcon ...	2000	11034285
phylogenetic analysis of gram-positive bacteria based on grpe, encoded by the dnak operon.	the dnak operon in gram-positive bacteria includes grpe, dnaj and, in some members, hrca as well. both dnak and dnaj have been utilized for constructing phylogenetic relationships among various organisms. multiple copies exist for dnak and dnaj genes in some bacterial genera, as opposed to a single gene copy for grpe and for hrca, according to the currently available data. here, we present a partial protein-based phylogenetic tree for gram-positive bacteria, derived by using the amino acid seque ...	2000	11034484
in-vitro activity and killing effect of polycationic peptides on methicillin-resistant staphylococcus aureus and interactions with clinically used antibiotics.	the in-vitro activity of nisin, a 34-residue peptide produced by several lactococcus lactis strains, and ranalexin, a 20-residue peptide isolated from the skin of the bullfrog rana catesbeiana, alone and in combination with amoxycillin, amoxycillin-clavulanate, imipenem, clarithromycin, ciprofloxacin, rifampin and vancomycin was investigated against 40 nosocomial isolates of methicillin-resistant staphylococcus aureus (mrsa). all isolates were inhibited at concentrations of 1 to 32 microg/ml. sy ...	2000	11035243
mutational analysis of two structural genes of the temperate lactococcal bacteriophage tp901-1 involved in tail length determination and baseplate assembly.	two putative structural genes, orf tmp (tape measure protein) and orf bpp (baseplate protein), of the temperate lactococcal phage tp901-1 were examined by introduction of specific mutations in the prophage strain lactococcus lactic ssp. cremoris 901-1. the adsorption efficiencies of the mutated phages to the indicator strain l. lactic ssp. cremoris 3107 were determined and electron micrographs were obtained. specific mutations in orf tmp resulted in the production of mostly phage head structures ...	2000	11040123
zinc uptake, oxidative stress and the fnr-like proteins of lactococcus lactis.	lactococcus lactis ssp. cremoris mg1363 contains two fnr homologues, flpa and flpb, encoded by the distal genes of two paralogous operons (orfx(a/b)-orfy(a/b)-flpa/b). an flpa flpb double mutant strain is hypersensitive to hydrogen peroxide and has a depleted intracellular zn(ii) pool. the phenotypes of the flp mutant strains suggest that flpa and flpb control the expression of high and low affinity atp-dependent zn(ii) uptake systems, respectively. plate tests revealed that expression from a or ...	2000	11040433
the life cycles of the temperate lactococcal bacteriophage philc3 monitored by a quantitative pcr method.	we present here a new and general approach for monitoring the life cycles of temperate bacteriophages which establish lysogeny by inserting their genomes site-specifically into the bacterial host chromosome. the method is based on quantitative amplification of specific dna sites involved in various cut-and-join events during the life cycles of the phages (i.e. the cos, attp, attb, attl and attr sites) with the use of sequence-specific primers. by comparing the amounts of these specific dna sites ...	2000	11040439
the conserved c-terminus of the citrate (citp) and malate (mlep) transporters of lactic acid bacteria is involved in substrate recognition.	the membrane potential-generating transporters citp of leuconostoc mesenteroides and mlep of lactococcus lactis are homologous proteins with 48% identical residues that catalyze citrate-lactate and malate-lactate exchange, respectively. the two transporters are highly specific for substrates containing a 2-hydroxycarboxylate motif (ho-cr(2)-coo(-)) in which substitutions of the r groups are tolerated well. differences in substrate specificity between mlep and citp are based on subtle changes in ...	2000	11041872
multiple homing pathways used by yeast mitochondrial group ii introns.	the yeast mitochondrial dna group ii introns ai1 and ai2 are retroelements that insert site specifically into intronless alleles by a process called homing. here, we used patterns of flanking marker coconversion in crosses with wild-type and mutant ai2 introns to distinguish three coexisting homing pathways: two that were reverse transcriptase (rt) dependent (retrohoming) and one that was rt independent. all three pathways are initiated by cleavage of the recipient dna target site by the intron- ...	2000	11046140
combinatorial peptide libraries reveal the ligand-binding mechanism of the oligopeptide receptor oppa of lactococcus lactis.	the oligopeptide transport system (opp) of lactococcus lactis has the unique capacity to mediate the transport of peptides from 4 up to at least 18 residues. the substrate specificity of this binding protein-dependent atp-binding cassette transporter is determined mainly by the receptor protein oppa. to study the specificity and ligand-binding mechanism of oppa, the following strategy was used: (i) oppa was purified and anchored via the lipid moiety to the surface of liposomes; (ii) the proteoli ...	2000	11050157
continuous production of lacticin 3147 and nisin using cells immobilized in calcium alginate.	bacteriocinogenic strains, lactococcus lactis subsp. lactis dpc 3147 and l. lactis dpc 496, producing lacticin 3147 and nisin, respectively, were immobilized in double-layered calcium alginate beads. these beads were inoculated into mrs broth at a ratio of 1:4 and continuously fermented for 180 h. free cells were used to compare the effect of immobilization on bacteriocin production. after equilibrium was reached, a flow rate of 580 ml h(-1) was used in the immobilized cell (ic), and 240 ml h(-1 ...	2000	11054159
[the production of antihypertensive peptides in beta-casein proteolysis].	antihypertensive peptides were obtained after the proteolysis of beta-casein by starter cells lactococcus lactis ssp. lactis and lactococci with pepsin or fromase. the peptides have shown the effect as inhibitors of angiotensin-converting enzyme. the strongest action the peptide obtained after the proteolysis of beta-casein by synergic action of lactococci with pepsin has shown. it demonstrates a capability of formation of such peptides directly in milk products during their making and maturatio ...	2000	11059391
identification of enterococcus species and phenotypically similar lactococcus and vagococcus species by reverse checkerboard hybridization to chaperonin 60 gene sequences.	data from four recent studies (s. h. goh et al., j. clin. microbiol. 36:2164-2166, 1998; s. h. goh et al., j. clin. microbiol. 34:818-823, 1996; s. h. goh et al., j. clin. microbiol. 35:3116-3121, 1997; a. y. c. kwok et al., int. j. syst. bacteriol. 49:1181-1192, 1999) suggest that an approximately 600-bp region of the chaperonin 60 (cpn60) gene, amplified by pcr with a single pair of degenerate primers, has utility as a potentially universal target for bacterial identification (id). this cpn60 ...	2000	11060051
molecular analysis of mutated lactobacillus acidophilus promoter-like sequence p15.	the promoter-like sequence p15 that was previously cloned from the chromosome of lactobacillus acidophilus atcc 4356 is active in lactobacillus reuteri, lactobacillus plantarum, lactobacillus acidophilus, and escherichia coli, but not in lactococcus lactis. n-methyl-n-nitroso-n-guanidine (mnng) mutagenesis of p15 was used to select for a promoter active in l. lactis mg1363. molecular analysis of the mutated promoter (designated p16) revealed a 90 bp deletion and a t-->a transversion. this deleti ...	2000	11068681
conditions for conjugative transposon transfer in lactococcus lactis.	three different techniques for bacterial mating were applied to wild type and culture collection strains of lactococcus lactis harbouring transposons: direct plate conjugation, filter mating and mating on milk agar. efficiencies and frequencies of transfer were compared. transconjugants were characterized by marker properties and molecular assays. transposon-coded suc+ nis+ phenotype as well as suc+ bac+ nis- phenotype were transferred with frequencies ranging between 10-9 and 10-6. milk agar pl ...	2000	11069634
germ therapy with il-10 to treat inflammatory bowel diseases.		2000	11074364
nucleotide sequence and analysis of pbl1, a bacteriocin-producing plasmid from lactococcus lactis ipla 972.	the complete sequence of the 10.9-kbp bacteriocinogenic plasmid pbl1 from lactococcus lactis subsp. lactis ipla 972 has been determined. thirteen orfs were encountered, of which 5 were incomplete. pbl1 proved to be a narrow-host-range plasmid which replicates neither in bacilus subtilis nor in lactobacillus spp. the structural organization of the pbl1 replication region was highly similar to other well-known theta-replicating plasmids of lactococci, at both the untranslated (the replication orig ...	2000	11078650
formation of biogenic amines in raw milk hispánico cheese manufactured with proteinases and different levels of starter culture.	two proteinases, a neutral proteinase from bacillus subtilis and a cysteine proteinase from micrococcus sp., were used to accelerate the ripening process of raw cow's milk hispánico cheese, a semihard variety. two levels (0.1% and 1%) of a commercial starter culture containing lactococcus lactis subsp. lactis and l. lactis subsp. cremoris were added for cheese manufacture. the influence of both factors, proteinase addition and level of starter culture, on the growth of amino acid-decarboxylating ...	2000	11079699
heterologously expressed staphylococcus aureus fibronectin-binding proteins are sufficient for invasion of host cells.	staphylococcus aureus invasion of mammalian cells, including epithelial, endothelial, and fibroblastic cells, critically depends on fibronectin bridging between s. aureus fibronectin-binding proteins (fnbps) and the host fibronectin receptor integrin alpha(5)beta(1) (b. sinha et al., cell. microbiol. 1:101-117, 1999). however, it is unknown whether this mechanism is sufficient for s. aureus invasion. to address this question, various s. aureus adhesins (fnbpa, fnbpb, and clumping factor [clfa]) ...	2000	11083807
fbpabc gene cluster in neisseria meningitidis is transcribed as an operon.	the neisserial fbpabc locus has been proposed to constitute a single transcriptional unit. to confirm this operonic arrangement, transcription assays using reverse transcriptase pcr amplification were conducted with neisseria meningitidis. the presence of fbpab and fbpbc transcripts obtained by priming cdna synthesis with an fbpc-sequence-specific oligonucleotide indicates that fbpabc is organized as a single expression unit. the ratio of fbpa to fbpabc mrna was approximately between 10- to 20-f ...	2000	11083849
inducible expression of enterococcus faecalis aggregation substance surface protein facilitates bacterial internalization by cultured enterocytes.	aggregation substance (as) is an enterococcus faecalis surface protein that may contribute to virulence. using a recently described system for controlled expression of as in e. faecalis and the heterologous host lactococcus lactis, experiments were designed to assess the effect of as on bacterial internalization by ht-29 and caco-2 enterocytes. as expression was associated with increased internalization of e. faecalis by ht-29 enterocytes and of l. lactis by ht-29 and caco-2 enterocytes. compare ...	2000	11083854
purification and characterisation of a beta-galactosidase from aspergillus aculeatus with activity towards (modified) exopolysaccharides from lactococcus lactis subsp. cremoris b39 and b891.	beta-galactosidase from aspergillus aculeatus was purified from a commercial source for its hydrolytic activity towards (modified) exopolysaccharides (epss) produced by lactococcus lactis subsp. cremoris b39 and b891. the enzyme had a molecular mass of approximately 120 kda, a pi between 5.3 and 5.7 and was optimally active at ph 5.4 and 55-60 degrees c. based on the n-terminal amino acid sequence, the enzyme probably belongs to family 35 of the glycosyl hydrolases. the catalytic mechanism was s ...	2000	11086688