evidence for horizontal transfer of ssudat1i restriction-modification genes to the streptococcus suis genome. | different strains of streptococcus suis serotypes 1 and 2 isolated from pigs either contained a restriction-modification (r-m) system or lacked it. the r-m system was an isoschizomer of streptococcus pneumoniae dpnii, which recognizes nucleotide sequence 5'-gatc-3'. the nucleotide sequencing of the genes encoding the r-m system in s. suis dat1, designated ssudat1i, showed that the ssudat1i gene region contained two methyltransferase genes, designated ssuma and ssumb, as does the dpnii system. th ... | 2001 | 11133943 |
analysis of six prophages in lactococcus lactis il1403: different genetic structure of temperate and virulent phage populations. | we report the genetic organisation of six prophages present in the genome of lactococcus lactis il1403. the three larger prophages (36-42 kb), belong to the already described p335 group of temperate phages, whereas the three smaller ones (13-15 kb) are most probably satellites relying on helper phage(s) for multiplication. these data give a new insight into the genetic structure of lactococcal phage populations. p335 temperate phages have variable genomes, sharing homology over only 10-33% of th ... | 2001 | 11160885 |
expression of clpx, an atpase subunit of the clp protease, is heat and cold shock inducible in lactococcus lactis. | in this study, the clpx gene and surrounding sequences were cloned and sequenced from lactococcus lactis. the putative clpx gene encodes a 411 amino acid polypeptide with a predicted molecular weight of 45.8 kda. analysis of the relative levels of clpx transcript revealed that in addition to a role in proteolysis of heat damaged proteins, clpx may also be involved in cryoprotection. | 2001 | 11518300 |
nisin biosynthesis in vitro. | the lantibiotic nisin is produced by lactococcus lactis. in the biosynthesis of nisin, the enzyme nisb dehydrates nisin precursor, and the enzyme nisc is needed for lanthionine formation. in this study, the nisa gene encoding the nisin precursor, and the genes nisb and nisc of the lantibiotic modification machinery were expressed together in vitro by the rapid translation system (rts). analysis of the rts mixture showed that fully modified nisin precursor was formed. by treating the mixture with ... | 2007 | 17827976 |
membrane topology of the sodium ion-dependent citrate carrier of klebsiella pneumoniae. evidence for a new structural class of secondary transporters. | the predicted secondary structure model of the sodium ion-dependent citrate carrier of klebsiella pneumoniae (cits) presents the 12-transmembrane helix motif observed for many secondary transporters. biochemical evidence presented in this paper is not consistent with this model. n-terminal and c-terminal fusions of cits with the biotin acceptor domain of the oxaloacetate decarboxylase of k. pneumoniae catalyze citrate transport, showing the correct folding of the cits part of the fusion proteins ... | 1996 | 8810332 |
genetic organization of the mle locus and identification of a mler-like gene from leuconostoc oenos. | characterization of the mle locus harboring the malolactic enzyme gene mlea and malate permease gene mlep from leuconostoc oenos was completed in this study by mrna analysis. northern (rna) blot experiments revealed a 2.6-kb transcript, suggesting an operon structure harboring mlea and mlep genes. primer extension analysis showed that the mle operon has a single transcription start site located 17 nucleotides upstream of the atg translation start site for the mlea gene. we found sequences, ttgac ... | 1996 | 8953720 |
identification of a cold shock gene in lactic acid bacteria and the effect of cold shock on cryotolerance. | when lactic acid bacterial cultures were frozen at -20 degrees c for 24 h, the cell viability decreased drastically, but when they were cold shocked at 10 degrees c for 2 h prior to freezing, viability improved significantly for the lactococcus lactis subsp. lactis strains (25-37%) and pediococcus pentosaceus po2 (18%), but not for the lactococcus lactis subsp. cremoris strains tested or for one strain of lactobacillus helveticus lb1 and streptococcus thermophilus ts2. when the period for cold s ... | 1997 | 9175562 |
bacterial multidrug resistance mediated by a homologue of the human multidrug transporter p-glycoprotein. | most atp-binding cassette (abc) multidrug transporters known to date are of eukaryotic origin, such as the p-glycoproteins (pgps) and multidrug resistance-associated proteins (mrps). only one well-characterized abc multidrug transporter, lmra, is of bacterial origin. on the basis of its structural and functional characteristics, this bacterial protein is classified as a member of the p-glycoprotein cluster of the abc transporter superfamily. lmra can even substitute for p-glycoprotein in human l ... | 2002 | 12120998 |
expression of the capsid protein of porcine circovirus type 2 in lactococcus lactis for oral vaccination. | diseases associated with porcine circovirus type 2 (pcv2) infections are becoming a major problem for the swine industry worldwide. the capsid protein (cap) of pcv2 is an antigen important for both early diagnosis and development of vaccines. in this study, lactococcus lactis was used as vehicle to deliver the pcv2 antigen in an attempt to develop oral vaccine. a cap gene with a deleted nuclear localization signal sequence (dcap) was cloned into an escherichia coli/l. lactis shuttle vector psec: ... | 2008 | 18406475 |
the lactococcus lactis fabf fatty acid synthetic enzyme can functionally replace both the fabb and fabf proteins of escherichia coli and the fabh protein of lactococcus lactis. | the genome of lactococcus lactis encodes a single long chain 3-ketoacyl-acyl carrier protein synthase. this is in contrast to its close relative, enterococcus faecalis, and to escherichia coli, both of which have two such enzymes. in e. faecalis and e. coli, one of the two long chain synthases (fabo and fabb, respectively) has a role in unsaturated fatty acid synthesis that cannot be satisfied by fabf, the other long chain synthase. since l. lactis has only a single long chain 3-ketoacyl-acyl ca ... | 2008 | 18523755 |
steady-state kinetics of the glutaminase reaction of ctp synthase from lactococcus lactis. the role of the allosteric activator gtp incoupling between glutamine hydrolysis and ctp synthesis. | ctp synthase catalyzes the reaction glutamine + utp + atp --> glutamate + ctp + adp + pi. the rate of the reaction is greatly enhanced by the allosteric activator gtp. we have studied the glutaminase half-reaction of ctp synthase from lactococcus lactis and its response to the allosteric activator gtp and nucleotides that bind to the active site. in contrast to what has been found for the escherichia coli enzyme, gtp activation of the l. lactis enzyme did not result in similar kcat values for th ... | 2002 | 12354108 |
characterization, expression, and mutation of the lactococcus lactis galpmkte genes, involved in galactose utilization via the leloir pathway. | a cluster containing five similarly oriented genes involved in the metabolism of galactose via the leloir pathway in lactococcus lactis subsp. cremoris mg1363 was cloned and characterized. the order of the genes is galpmkte, and these genes encode a galactose permease (galp), an aldose 1-epimerase (galm), a galactokinase (galk), a hexose-1-phosphate uridylyltransferase (galt), and a udp-glucose 4-epimerase (gale), respectively. this genetic organization reflects the order of the metabolic conver ... | 2003 | 12533462 |
attenuation regulation of amino acid biosynthetic operons in proteobacteria: comparative genomics analysis. | candidate attenuators were identified that regulate operons responsible for biosynthesis of branched amino acids, histidine, threonine, tryptophan, and phenylalanine in gamma- and alpha-proteobacteria, and in some cases in low-gc gram-positive bacteria, thermotogales and bacteroidetes/chlorobi. this allowed us not only to describe the evolutionary dynamics of regulation by attenuation of transcription, but also to annotate a number of hypothetical genes. in particular, orthologs of ygea of esche ... | 2004 | 15135544 |
lipid-mediated light activation of a mechanosensitive channel of large conductance. | this paper describes the reversible activation of a mechanosensitive channel via a light-sensitive lipid mimic. for these experiments, the mechanosensitive channel of large conductance (mscl) protein from lactococcus lactis and escherichia coli was reconstituted in lipid bilayers composed of 80 mol % 1,2-dioleoyl-sn-glycero-3-phosphocholine and 20 mol % di-(5-[[4-(4-butylphenyl)azo]phenoxy]pentyl)phosphate (4-azo-5p). light-induced isomerization of the azobenzene moiety of 4-azo-5p from trans to ... | 2004 | 15301476 |
large increase in brazzein expression achieved by changing the plasmid /strain combination of the nice system in lactococcus lactis. | to evaluate brazzein production in lactococcus lactis using the nisin-controlled expression (nice) system. the approach is through analysis of different plasmid/strain combinations. | 2009 | 19413801 |
ferrihydrite reduction by geobacter species is stimulated by secondary bacteria. | geobacter species such as g. bremensis, g. pelophilus, and g. sulfurreducens are obligately anaerobic and grow in anoxic, non-reduced medium by fast reduction of soluble ferric citrate. in contrast, insoluble ferrihydrite was either only slowly or not reduced when supplied as electron acceptor in similar growth experiments. ferrihydrite reduction was stimulated by addition of a reducing agent or by concomitant growth of secondary bacteria that were physiologically and phylogenetically as diverse ... | 2004 | 15340790 |
using lactococcus lactis for glutathione overproduction. | glutathione and gamma-glutamylcysteine were produced in lactococcus lactis using a controlled expression system and the genes gsha and gshb from escherichia coli encoding the enzymes gamma-glutamylcysteine synthetase and glutathione synthetase. high levels of gamma-glutamylcysteine were found in strains growing on chemically defined medium and expressing either gsha alone or both gsha and gshb. as anticipated, glutathione was found in a strain expressing gsha and gshb. the level of glutathione p ... | 2005 | 15490155 |
a nudix enzyme removes pyrophosphate from dihydroneopterin triphosphate in the folate synthesis pathway of bacteria and plants. | removal of pyrophosphate from dihydroneopterin triphosphate (dhntp) is the second step in the pterin branch of the folate synthesis pathway. there has been controversy over whether this reaction requires a specific pyrophosphohydrolase or is a metal ion-dependent chemical process. the genome of lactococcus lactis has a multicistronic folate synthesis operon that includes an open reading frame (ylgg) specifying a putative nudix hydrolase. because many nudix enzymes are pyrophosphohydrolases, ylgg ... | 2004 | 15611104 |
function of prokaryotic and eukaryotic abc proteins in lipid transport. | atp binding cassette (abc) proteins of both eukaryotic and prokaryotic origins are implicated in the transport of lipids. in humans, members of the abc protein families a, b, c, d and g are mutated in a number of lipid transport and metabolism disorders, such as tangier disease, stargardt syndrome, progressive familial intrahepatic cholestasis, pseudoxanthoma elasticum, adrenoleukodystrophy or sitosterolemia. studies employing transfection, overexpression, reconstitution, deletion and inhibition ... | 2004 | 15749056 |
transcriptional analysis of the cyclopropane fatty acid synthase gene of lactococcus lactis mg1363 at low ph. | cyclopropane fatty acid synthase (cfa) catalyses the transfer of a methyl group from s-adenosylmethionine (sam) to unsaturated fatty acids. northern blot experiments demonstrated that the lactococcus lactis mg1363 cfa gene is mainly expressed as a bicistronic transcript together with metk, the gene encoding sam synthetase, and is highly induced by acidity. the cfa promoter was characterized by 5'-race pcr, and fused to beta-galactosidase by cloning into the pak80 plasmid. this transcriptional fu ... | 2005 | 16098686 |
molecular analysis of colonized bacteria in a human newborn infant gut. | the complex ecosystem of intestinal microflora is estimated to harbor approximately 400 different microbial species, mostly bacteria. however, studies on bacterial colonization have mostly been based on culturing methods, which only detect a small fraction of the whole microbiotic ecosystem of the gut. to clarify the initial acquisition and subsequent colonization of bacteria in an infant within the few days after birth, phylogenetic analysis was performed using 16s rdna sequences from the dna i ... | 2005 | 16145549 |
expression of helicobacter pylori cag12 gene in lactococcus lactis mg1363 and its oral administration to induce systemic anti-cag12 immune response in mice. | to develop an oral vaccine against helicobacter pylori infection, we have expressed the h. pylori cag12 (hp0532) gene, encoding the outer membrane protein cag12 (31 kda), in a live delivery vehicle lactococcus lactis. the cag12 gene was amplified by polymerase chain reaction (pcr) using the genomic dna of h. pylori k51 isolated from korean patients. dna sequence analysis revealed that the cag12 gene of h. pylori k51 has 98.1 and 97.4% identity with individual cag12 genes of the h. pylori 26695 a ... | 2006 | 16586107 |
restriction for gene insertion within the lactococcus lactis ll.ltrb group ii intron. | the ll.ltrb intron, from the low g+c gram-positive bacterium lactococcus lactis, was the first bacterial group ii intron shown to splice and mobilize in vivo. the detailed retrohoming and retrotransposition pathways of ll.ltrb were studied in both l. lactis and escherichia coli. this bacterial retroelement has many features that would make it a good gene delivery vector. here we report that the mobility efficiency of ll.ltrb expressing ltra in trans is only slightly affected by the insertion of ... | 2006 | 16973892 |
lex marks the spot: the virulent side of sos and a closer look at the lexa regulon. | the sos response that responds to dna damage induces many genes that are under lexa repression. a detailed examination of lexa regulons using genome-wide techniques has recently been undertaken in both escherichia coli and bacillus subtilis. these extensive and elegant studies have now charted the extent of the lexa regulons, uncovered many new genes, and exposed a limited overlap in the lexa regulon between the two bacteria. as more bacterial genomes are analysed, more curiosities in lexa regul ... | 2006 | 17042786 |
universal method for synthesis of artificial gel antibodies by the imprinting approach combined with a unique electrophoresis technique for detection of minute structural differences of proteins, viruses, and cells (bacteria). iii: gel antibodies against cells (bacteria). | artificial antibodies in the form of gel granules were synthesized from the monomers acrylamide and n,n'-methylenebisacrylamide by the imprinting method in the presence of echerichia coli bacteria as template. the electrophoretic migration velocities of the gel antibodies (i) saturated with the antigen (escherichia coli mre-600), (ii) freed of the antigen, and (iii) resaturated with bacteria, were determinated by electrophoresis in a rotating narrow-bore tube of 245 mm length and the 2.5 and 9.6 ... | 2006 | 17136716 |
human lysozyme expressed in the mammary gland of transgenic dairy goats can inhibit the growth of bacteria that cause mastitis and the cold-spoilage of milk. | the addition of human milk components with intrinsic antimicrobial activity to livestock milk by genetic engineering has the potential to benefit milk safety and production as well as the health of the lactating animal. as a model for the dairy cow, we generated transgenic goats that expressed human lysozyme in their milk at 68% of the levels found in human milk. milk from these transgenic animals had a bacteriostatic effect on both in vitro and in vivo growth of several microorganisms important ... | 2006 | 17199520 |
characterization of the lactococcal group ii intron target site in its native host. | the lactococcus lactis group ii intron (ll.ltrb) retrohomes into the ltrb gene at high efficiency. to date, the critical dna bases recognized in vivo by the ll.ltrb ribonucleoprotein (rnp) have been exclusively elucidated in escherichia coli. however, recent evidence indicates host-dependant differences in ll.ltrb mobility, raising the possibility of limitations of the current model for rnp-homing site recognition in the native l. lactis host. in this work, intron retargeting experiments in l. l ... | 2007 | 17408740 |
short communication: characterization of microflora in mexican chihuahua cheese. | this work was performed to identify the bacterial species present in 10 chihuahua cheeses obtained from commercial producers in mexico using 16s rrna gene analysis. as expected, some of the agar media initially used for isolation were not very selective, supporting the growth of several unrelated bacterial species. sequence analysis identified potential pathogens, including escherichia coli and staphylococcus aureus, in all raw milk samples and 2 pasteurized milk samples. streptococcus thermophi ... | 2011 | 21700016 |
improvement of a nisin-inducible expression vector for use in lactic acid bacteria. | the plasmid pmsp3535 is a popular vector for nisin-inducible expression of heterologous genes in lactic acid bacteria. however, the maximum protein expression level achievable with pmsp3535 is relatively low. in an effort to increase expression we modified pmsp3535 to create a high expression variant termed pmsp3535h2. modifications included removal of a small nisa peptide fragment from the p nisa promoter and addition of a bidirectional transcription terminator. in addition the plasmid copy num ... | 2007 | 17624430 |
construction of theta-type shuttle vector for leuconostoc and other lactic acid bacteria using pcb42 isolated from kimchi. | the pcb42 plasmid from leuconostoc citreum cb2567, a strain isolated from kimchi, was characterized, and a shuttle vector for escherichia coli and lactic acid bacteria (lab) was constructed. the pcb42 plasmid has a circular structure of 4312bp, a low g+c content, and no single-stranded dna intermediates during replication, which indicates that pcb42 replicates via the theta-type replication mechanism. in silico analysis of this plasmid revealed 6 open reading frames: 1 transposase gene, 1 dna-bi ... | 2012 | 22133745 |
phage tp901-1 site-specific integrase functions in human cells. | we demonstrate that the site-specific integrase encoded by phage tp901-1 of lactococcus lactis subsp. cremoris has potential as a tool for engineering mammalian genomes. we constructed vectors that express this integrase in escherichia coli and in mammalian cells and developed a simple plasmid assay to measure the frequency of intramolecular integration mediated by the integrase. we used the assay to document that the integrase functions efficiently in e. coli and determined that for complete re ... | 2002 | 12057961 |
molecular characterization of a clostridium difficile bacteriophage and its cloned biologically active endolysin. | clostridium difficile infection is increasing in both frequency and severity, with the emergence of new highly virulent strains highlighting the need for more rapid and effective methods of control. here, we show that bacteriophage endolysin can be used to inhibit and kill c. difficile. the genome sequence of a novel bacteriophage that is active against c. difficile was determined, and the bacteriophage endolysin gene was subcloned and expressed in escherichia coli. the partially purified endoly ... | 2008 | 18708505 |
introduction of an nadh regeneration system into klebsiella oxytoca leads to an enhanced oxidative and reductive metabolism of glycerol. | redox cofactors play crucial roles in the metabolic and regulatory network of living organisms. we reported here the effect of introducing a heterogeneous nadh regeneration system into klebsiella oxytoca on cell growth and glycerol metabolism. expression of fdh gene from candida boidinii in k. oxytoca resulted in higher intracellular concentrations of both nadh and nad(+) during the fermentation metaphase, with the ratio of nadh to nad(+) unaltered and cell growth unaffected, interestingly diffe ... | 2009 | 19100856 |
eci5, a group iib intron with high retrohoming frequency: dna target site recognition and use in gene targeting. | we find that group ii intron eci5, a subclass cl/iib1 intron from an escherichia coli virulence plasmid, is highly active in retrohoming in e. coli. both full-length eci5 and an eci5-deltaorf intron with the intron-encoded protein expressed separately from the same donor plasmid retrohome into a recipient plasmid target site at substantially higher frequencies than do similarly configured lactococcus lactis ll.ltrb introns. a comprehensive view of dna target site recognition by eci5 was obtained ... | 2009 | 19155322 |
secretory expression of k88 (f4) fimbrial adhesin faeg by recombinant lactococcus lactis for oral vaccination and its protective immune response in mice. | k88 (f4) fimbrial adhesin, faeg, was expressed extracellularly in lactococcus lactis using a nisin-controlled gene expression system. the antibody response and protective efficacy of the recombinant bacteria (l. lactis [spnz8048-faeg]) against live enterotoxigenic e. coli (etec) c(83549) challenge were evaluated in icr mice. mice vaccinated with l. lactis [spnz8048-faeg] had a significantly increased antigen-specific igg level in the serum and decreased mortality rate (p < 0.05) compared with th ... | 2009 | 19277476 |
inhibition of uropathogens by lactic acid bacteria isolated from dairy foods and cow's intestine in western nigeria. | a total of 96 lactic acid bacteria (lab) were isolated from african indigenous fermented products and cow's intestines to study their inhibitory capability against multi-drug-resistant uropathogens. escherichia coli accounted for approximately 45% of isolated uropathogens, followed by staphylococcus spp. (20%). the gram negative uropathogens were highly resistant to quinolones, co-trimoxazole, teicoplanin and some beta-lactams, while the staphylococcus spp. showed high resistance to aminoglycosi ... | 2009 | 19529917 |
possible promoter regions within the proteolytic system in streptococcus thermophilus and their interaction with the cody homolog. | possible promoter regions preceding 14 genes belonging to the proteolytic system of streptococcus thermophilus klds 3.0503 were predicted by a promoter analysis software nnpp. the 14 genes included an extracellular protease gene prts, an oligopeptide abc transport system gene amia1, and 12 genes, respectively, encoding peptidases pepa, peps, pepn, pepc, pepb, pepq, pepv, pept, pepm, pepxp, pepp, and pepo. these predicted promoter sequences were cloned and inserted into the upstream of a promoter ... | 2009 | 19552712 |
intra- and interspecies conjugal transfer of tn916-like elements from lactococcus lactis in vitro and in vivo. | tetracycline-resistant lactococcus lactis strains originally isolated from polish raw milk were analyzed for the ability to transfer their antibiotic resistance genes in vitro, using filter mating experiments, and in vivo, using germfree rats. four of six analyzed l. lactis isolates were able to transfer tetracycline resistance determinants in vitro to l. lactis bu2-60, at frequencies ranging from 10(-5) to 10(-7) transconjugants per recipient. three of these four strains could also transfer res ... | 2009 | 19666731 |
molecular properties of the glucosaminidase acma from lactococcus lactis mg1363: mutational and biochemical analyses. | the major autolysin acma of lactococcus lactis ssp. cremoris mg1363 is a modular protein consisting of an n-terminal signal sequence, a central enzymatic region (glu(acma) as a glucosaminidase), and a c-terminal cell-recognition domain (lysm123). glu(acma) (about 160 amino acids) belongs to the glycoside hydrolase (gh) 73 family, and the two acidic residues e128 and d153 have been thought to be catalytically important. in this study, amino-acid substitution analysis of acma was first carried out ... | 2009 | 19686822 |
oral administration of lactococcus lactis expressing helicobacter pylori cag7-ct383 protein induces systemic anti-cag7 immune response in mice. | to express the 3'-region (1152 bp) of the cag7 gene of helicobacter pylori 51 strain, encoding the c-terminal 383 amino acid (ct383 aa) region of cag7 protein that is known to cover the needle region of t4ss, in a live delivery vehicle lactococcus lactis, the cag7-ct383 gene was amplified by pcr. dna sequence analysis revealed that the amino acid sequence of cag7-ct383 of h. pylori 51 shared 98.4% and 97.4% identity with h. pylori 26695 and j99, respectively. intramuscular injection of the gst-c ... | 2009 | 19807786 |
expression of espa in lactococcus lactis nz9000 and the detection of its immune effect in vivo and vitro. | enterhemorrhagic escherichia coli (epec), an important cause of severe infantile diarrheal disease in many parts of the developing world, produced several recently described virulence determinations. several of its virulence factors are secreted by type iii secretion including espa, which forms filamentous structures on bacterial surface bridging to the host cell's surface. these structures on bacterial surfaces may deliver other virulence factors directly into the host cell from ehec. in this s ... | 2010 | 20001787 |
immune responses elicited in mice with recombinant lactococcus lactis expressing f4 fimbrial adhesin faeg by oral immunization. | enterotoxigenic escherichia coli (etec) is a major pathogenic agent causing piglet diarrhea. the major subunit and adhesin faeg of f4(+) etec is an important virulence factor with strong immunogenicity. to determine whether lactococcus lactis (l. lactis) could effectively deliver faeg to the mucosal immune system, recombinant l. lactis expressing faeg was constructed, and immune responses in mice following oral route delivery of recombinant l. lactis were explored. the production of faeg express ... | 2010 | 20532816 |
origin of the putrescine-producing ability of the coagulase-negative bacterium staphylococcus epidermidis 2015b. | a multiplex pcr method, aimed at the detection of genes associated with biogenic amine production, identified the odc gene encoding ornithine decarboxylase in 1 of 15 strains of staphylococcus epidermidis. the ability of the positive strain, s. epidermidis 2015b, to produce putrescine in vitro was demonstrated by high-performance liquid chromatography (hplc). in this strain, the odc gene was detected on plasmid dna, suggesting that the ability to form putrescine is carried by a mobile element, w ... | 2010 | 20581187 |
the unconventional xer recombination machinery of streptococci/lactococci. | homologous recombination between circular sister chromosomes during dna replication in bacteria can generate chromosome dimers that must be resolved into monomers prior to cell division. in escherichia coli, dimer resolution is achieved by site-specific recombination, xer recombination, involving two paralogous tyrosine recombinases, xerc and xerd, and a 28-bp recombination site (dif) located at the junction of the two replication arms. xer recombination is tightly controlled by the septal prote ... | 2007 | 17630835 |
identification of lactic acid bacteria within the consortium of a kefir grain by sequencing 16s rdna variable regions. | the microflora of a kefir grain was identified using a polymerase chain reaction-based strategy combined with 16s rrna gene sequencing. dna was extracted from the kefir grain and amplified in its 16s rdna v1 and v2 regions. to guarantee a good representation of the overall lactic acid bacteria populations, dna amplification was performed separately with primers specific either to the dominant or to the less abundant bacterial groups. the amplified fragments were cloned in escherichia coli and th ... | 2007 | 17760349 |
on the energy-dependence of hoechst 33342 transport by the abc transporter lmra. | lmra is an atp-binding cassette (abc) multidrug transporter from lactococcus lactis, and is a structural homologue of the human multidrug resistance p-glycoprotein (abcb1), the overexpression of which is associated with multidrug resistance in tumours. we recently observed that a truncated version of lmra lacking the nucleotide-binding domain mediates a proton motive force-dependent ethidium transport reaction by catalyzing proton-ethidium symport. this finding raised the question whether proton ... | 2008 | 18061142 |
structure of the branched-chain keto acid decarboxylase (kdca) from lactococcus lactis provides insights into the structural basis for the chemoselective and enantioselective carboligation reaction. | the thiamin diphosphate (thdp) dependent branched-chain keto acid decarboxylase (kdca) from lactococcus lactis catalyzes the decarboxylation of 3-methyl-2-oxobutanoic acid to 3-methylpropanal (isobutyraldehyde) and co2. the enzyme is also able to catalyze carboligation reactions with an exceptionally broad substrate range, a feature that makes kdca a potentially valuable biocatalyst for c-c bond formation, in particular for the enzymatic synthesis of diversely substituted 2-hydroxyketones with h ... | 2007 | 18084069 |
bidirectional cell-surface anchoring function of c-terminal repeat region of peptidoglycan hydrolase of lactococcus lactis il1403. | with the aim of constructing an efficient protein display system for lactic acid bacteria (labs), the effect of fusion direction on the cell-surface binding activity of the c-terminal region of the peptidoglycan hydrolase (cph) of lactococcus lactis il1403 was studied. cph fused to the alpha-amylase (amy) of streptococcus bovis 148 either at its c-terminus (cph-amy) or at its n-terminus (amy-cph) was expressed intracellularly in escherichia coli. this domain was able to direct binding of amy to ... | 2008 | 18343337 |
expression of c-terminal repeat region of peptidoglycan hydrolase of lactococcus lactis il1403 in methylotrophic yeast pichia pastoris. | the c-terminal region of the peptidoglycan hydrolase (cph) of lactococcus lactis il1403 produced intracellularly in escherichia coli was able to attach to the surface of cells of lactobacillus casei nrrl b-441, bacillus subtilis 168, e. coli xl1-blue and saccharomyces cerevisiae ifo0216. therefore, this domain is a suitable fusion partner for the adhesion of proteins to cell surfaces. the production of cell-surface adhesive proteins using this domain in pichia pastoris is particularly attractive ... | 2008 | 18343340 |
metabolic engineering of escherichia coli for the production of succinate from glycerol. | glycerol has become an ideal feedstock for the microbial production of bio-based chemicals due to its abundance, low cost, and high degree of reduction. we have previously reported the pathways and mechanisms for the utilization of glycerol by escherichia coli in minimal salts medium under microaerobic conditions. here we capitalize on such results to engineer e. coli for the production of value-added succinate from glycerol. through metabolic engineering of e. coli metabolism, succinate product ... | 2010 | 20601068 |
uplc/ms based method for quantitative determination of fatty acid composition in gram-negative and gram-positive bacteria. | quantitative fatty acid composition of microorganisms at various growth space points is required for understanding membrane associated processes of cells, but the majority of the relevant publications still restrict to the relative compositions. in the current study, a simple and reliable method for quantitative measurement of fatty acid content in bacterial biomass without prior derivatization using ultra performance liquid chromatography-electrospray ionization mass spectrometry was developed. ... | 2010 | 20621131 |
a novel plasmid for delivering genes into mammalian cells with noninvasive food and commensal lactic acid bacteria. | using food and commensal lactic acid bacteria (lab) as vehicles for dna delivery into epithelial cells is a new strategy for vaccine delivery or gene therapy. however, present methods for dna delivery with lab have suffered low efficiency. our goal was to develop a new system to deliver dna into epithelial cells with high efficiency using food and commensal lab. an escherichia coli-lab shuttle plasmid, plkv1, for dna delivery into eukaryotic cells was constructed. two reporter plasmids with gree ... | 2011 | 20832422 |
screening for antimicrobial resistance genes and virulence factors via genome sequencing. | second-generation genome sequencing and alignment of the resulting reads to in silico genomes containing antimicrobial resistance and virulence factor genes were used to screen for undesirable genes in 28 strains which could be used in human nutrition. no virulence factor genes were detected, while several isolates contained antimicrobial resistance genes. | 2011 | 21335393 |
biosynthesis of polyhydroxyalkanoates containing 2-hydroxybutyrate from unrelated carbon source by metabolically engineered escherichia coli. | we have previously reported in vivo biosynthesis of polylactic acid (pla) and poly(3-hydroxybutyrate-co-lactate) [p(3hb-co-la)] employing metabolically engineered escherichia coli strains by the introduction of evolved clostridium propionicum propionyl-coa transferase (pct( cp )) and pseudomonas sp. mbel 6-19 polyhydroxyalkanoate (pha) synthase 1 (phac1( ps6-19)). using this in vivo pla biosynthesis system, we presently report the biosynthesis of phas containing 2-hydroxybutyrate (2hb) monomer b ... | 2011 | 21842437 |