n-nitrosamine formation by cultures of several microorganisms.of 38 pure cultures of microorganisms tested, only one, pseudomonas stutzeri, was capable of forming dimethylnitrosamine from dimethylamine and nitrite during growth. resting cells of p. stutzeri, cryptococcus terreus, escherichia coli, and xanthomonas campestris formed dimethylnitrosamine, although no nitrosamine was found in growing cultures of the latter three organisms. no nitrosamine was produced by either growing cultures or resting-cell suspensions of pseudomonas fragi or proteus mirabili ...19767197
conformation of the extracellular polysaccharide of xanthomonas campestris.the solution conformation of the extracellular polysaccharide of the bacterium xanthomonas campestris is examined by optical rotation, viscometry, and potentiometric titration. measurements of optical rotation vs. temperature for solutions of the polysaccharide at low ionic strength reveal a sharp transition to a denatured structure which is reversible if sufficient salt is present. the temperature tm at the transition midpoint increases as log (na+) or log (ca2+). viscosity-temperature profiles ...19769135
bacteriolysis by immobilized enzymes.bacteriolytic enzymes produced by achromobacter lunatus were immobilized in collagen membrane. intact bacteria such as pseudomonas solanacearum, xanthomonas oryzae, staphylococcus aureus, and pseudomonas aeruginosa were lyzed with the bacteriolytic enzyme-collagen membrane. relative activity of the bacteriolytic enzyme-collagen membrane against pseu. solanacearum was about 2% of that of native bacteriolytic enzymes. no difference in the optimum ph was observed between immobilized enzymes and nat ...197714747
combining site specificity of antipneumococcal type viii horse immunoglobulins cross-reactive with mild acid-treated xanthomonas campestris polysaccharide. 197828090
maintenance procedures for the curtailment of genetic instability: xanthomonas campestris nrrl b-1459.characteristics are described of small-colony variants of xanthomonas campestris nrrl b-1459 which are frequently encountered when routine culture maintenance procedures are employed. in contrast to the parental type, smallcolony variants were shown to be resistant to a number of antibiotics, to acridine orange, and to phage which are virulent for the parent colony type. sensitivity to ultraviolet radiation was similar in both colony types. a simple method for preservation of viable cells is des ...1977326188
antagonistic interactions of phylloplane bacteria with drechslera dictyoides (drechslera) shoemaker.strains of listeria denitrificans (e2), pseudomonas fluorescens (c37 and c92), and xanthomonas campestris (d119), isolated from the phylloplane of lolium perenne (s24), were antagonistic to drechslera dictyoides (drechslera) shoemaker. from in vitro and in vivo experiments it was deduced that their mode of activity included an initial inhibition of spore germination, a retardation in the rate of germ-tube elongation, and ultimately lysis of the hyphae. the effects were expressed on the plant in ...1977406025
further evidence for the regulation of bacterial populations in soil by protozoa.after the addition to soil of large numbers of a cowpea rhizobium strain, the population declined steadily until the numbers reached about 10(7)/g, and the protozoa rose to about 10(4)/g. when indigenous protozoa were suppressed by the addition of actidione to the soil, the density of the test rhizobium did not fall initially, but its abundance declined to about 10(7)/g when actidione-resistant protozoa arose in significant numbers. the addition to actidione-treated soil of an antibiotic-resista ...1977879960
[nitrogen utilization and xanthan production by xanthomonas campestris].in media with mixed nitrogen sources (nitrate plus yeast extract) a three auxic growth is observed. the first growth phase is characterized by preferential utilization of the amino acids of the yeast autolysate and the utilization of only small amounts of nitrate. during the second growth phase nitrate is preferentially utilized. in the third phase there is only growth without dividing of cells and the accumulation of xanthan takes place. the change from growth by dividing to growth without divi ...1977930119
colonial variation in xanthomonas campestris nrrl b-1459 and characterization of the polysaccharide from a variant strain.stock cultures of xanthomonas campestris nrrl b-1459 require special attention to maintenance and propagation to assure consistent production in good yields of the extracellular polysaccharide xanthan. under customary conditions of propagative maintenance on agar slants, variant colony types develop that are smaller in size than the normal type. the rate of regression of the normal to the variant forms was diminished when the d-glucose content of the stock medium was sufficient to avoid depletio ...1976963616
protozoa as agents responsible for the decline of xanthomonas campestris in soil.a streptomycin-resistant mutant of xanthomonas campestris was used to assess the persistence of the plant pathogen in soil and the changes in populations that might be important for its survival. in soil into which large numbers of the organism were introduced, a marked decline in its abundance occurred, but after about 1 week its population density reached a level of about 105 and did not continue to fall during the test period. no such marked decline was evident in sterile soil inoculated wit ...19751115496
structure of extracellular polysaccharide from xanthomonas campestris. 19751212669
covalent structure of the extracellular polysaccharide from xanthomonas campestris: evidence from partial hydrolysis studies. 19761260790
the production of hybridoma cell line secreting monoclonal antibodies against xanthomonas campestris pv. oryzae and its application in the classification of the fusion of mouse myeloma cells (sp2/0-ag14) and spleen cells derived from balb/c mice immunized with the preparation of xanthomonas campestris pv. oryzae ks-6-6, os-213, yz-32 and yz-24, we obtained 12 hybridoma cell lines secreting monoclonal antibodies. none of the mcabs cross-reacted with the other varieties of plant pathogenetic and non-pathogenetic bacteria. the mcabs could distinguish three variant serotypes of strains. antibody titers of ascites were about 1:10(3)-1:10(6) when measu ...19921284289
[production of xanthan gum in immobilized cultures of xanthomonas campestris].the efficiency of xanthan production through surface processes was evaluated. the best porous material was selected first. thereafter, a comparative study was performed using submerged agitated process vs other without agitation but containing the selected porous material. the culture medium used was white potatoes infusion, buffered with k2hpo4 and supplemented with glucose in diverse concentrations. besides, to evaluate a different type of surface process, three vegetables were valued: ipomaea ...19921298018
use of bioluminescence for detection of genetically engineered microorganisms released into the environment.the persistence and movement of strain js414 of xanthomonas campestris pv. campestris, which was genetically engineered to bioluminesce, were monitored during a limited field introduction. bioluminescence and traditional dilution plate counts were determined. strain js414 was applied to cabbage plants and surrounding soil by mist inoculation, by wound inoculation, by scattering infested debris among plants, and by incorporating bacteria into the soil. bioluminescent x. campestris pv. campestris ...19921311542
cloning and characterization of pathogenicity genes from xanthomonas campestris pv. glycines.nonpathogenic mutants of xanthomonas campestris pv. glycines 8ra were generated with n-methyl-n-nitro-n'-nitrosoguanidine to identify and characterize pathogenicity genes of the bacterium. a total of 16 nonpathogenic mutants were isolated from 2,000 colonies. one mutant, np1, was chosen for further study. np1 did not multiply in soybean cotyledons. a genomic library of strain 8ra was constructed in the cosmid plafr3, and the cosmids were tested for complementation in np1. one cosmid clone, pih1, ...19921312532
cloning and characterization of a gene required for the secretion of extracellular enzymes across the outer membrane by xanthomonas campestris pv. campestris.nonpathogenic mutants of xanthomonas campestris pv. campestris, generated from transposon mutagenesis, accumulated extracellular polygalacturonate lyase, alpha-amylase, and endoglucanase in the periplasm. the transposon tn5 was introduced by a mobilizable, suicidal plasmid, psup2021 or peydg1. genomic banks of wild-type x. campestris pv. campestris, constructed on the broad-host-range, mobilizable cosmid plafr1 or plafr3, were conjugated with one of the mutants, designated xc1708. recombinant pl ...19921313415
dna binding specificity and sequence of xanthomonas campestris catabolite gene activator protein-like protein.the xanthomonas campestris catabolite gene activator protein-like protein (clp) can substitute for the escherichia coli catabolite gene activator protein (cap) in transcription activation at the lac promoter (v. de crecy-lagard, p. glaser, p. lejeune, o. sismeiro, c. barber, m. daniels, and a. danchin, j. bacteriol. 172:5877-5883, 1990). we show that clp has the same dna binding specificity as cap at positions 5, 6, and 7 of the dna half site. in addition, we show that the amino acids at positio ...19921322886
cloning and characterization of a pectate lyase gene from the soft-rotting bacterium pseudomonas viridiflava.pseudomonas viridiflava is a soft-rotting pathogen of harvested vegetables that produces an extracellular pectate lyase (pl) responsible for maceration of plant tissue. a pel gene encoding pl was cloned from the genome of strain sj074 and efficiently expressed in escherichia coli. after a series of deletion subclonings and analysis by transposon mutagenesis, the pel gene was located in a 1.2-kb psti-bglii genomic fragment. this fragment appears to contain a promoter at the psti end required for ...19921325218
identification of a family of avirulence genes from xanthomonas oryzae pv. oryzae.races of xanthomonas oryzae pv. oryzae, the causal agent of bacterial blight of rice, interact with cultivars of rice in a gene-for-gene specific manner. multiple dna fragments of various sizes from all strains of x. o. pv. oryzae hybridized with avrbs3, an avirulence gene from xanthomonas campestris pv. vesicatoria, in southern blots; this suggests the presence of several homologs and possibly a gene family. a genomic library of a race 2 strain of x. o. pv. oryzae, which is avirulent on rice cu ...19921335800
genetic engineering of polysaccharide structure: production of variants of xanthan gum in xanthomonas campestris.xanthan gum is an extracellular heteropolysaccharide produced by the bacterium xanthomonas campestris. xanthan has wide commercial application as a viscosifier of aqueous solutions. previously, through genetic engineering, a set of mutants defective in the xanthan biosynthetic pathway has been obtained. certain mutants were shown to synthesize and polymerize structural variants of the xanthan repeating unit and thus produce "variant xanthans". initial studies of solution viscosities of these pol ...19901366611
production of monoclonal antibodies to pseudomonas syringae pv. phaseolicola and xanthomonas campestris pv. phaseoli.the production of monoclonal antibodies (mabs) to ethylenediamine tetraacetic acid (sodium salt) soluble antigens of pseudomonas syringae pv. phaseolicola and xanthomonas campestris pv. phaseoli (fuscans strain) is described. mabs a6-1 and a6-2 produced to ps. syringae pv. phaseolicola are pathovar specific. although mab xp2 produced to x. campestris pv. phaseoli recognized surface antigens of all strains of this pathovar (including fuscans strains) it cross-reacted specifically with x. campestr ...19901367453
increase of xanthan production by cloning xps genes into wild-type xanthomonas campestris.previously, genomic banks of xanthomonas campestris were constructed in escherichia coli, using mobilizable broad-host-range cosmids as the vectors. following conjugal transfer, genes involved in the biosynthesis of xanthan polysaccharide (xps) were cloned by the ability to restore the mucoid phenotype to the non-mucoid mutants. in this study, all clones were transferred into the wild-type strain xc17 to evaluate the effects of the cloned genes on xps production. most clones showed no significan ...19921367903
electrotransformation of xanthomonas campestris by rf dna of filamentous phage phi lf.conditions were optimized for electrotransformation of xanthomonas campestris pv. campestris by the replicative form (rf) dna of filamentous phase phi lf. early logarithmic cells were washed exhaustively with deionized water and subjected to a pulse at a field strength of 12.5 kv/cm with a 25 microf capacitor and a 400 omega resistor. an efficiency of 5.1 x 10(7) pfu per microgram rf dna was obtained. under the same conditions, the broad host range plasmid plafr1 (21.6 kb) transformed x. campest ...19921367905
effect of parb on plasmid stability and gene expression in xanthomonas campestris.the stabilization locus parb was subcloned into the broad host range plasmid pap2, which contains the alpha-amylase gene from bacillus subtilis, and introduced into xanthomonas campestris pv campestris and x.c.pv manihotis. analysis of the stability of plasmid pap2 (parb-) and pap23 (parb+) showed that the parb locus decreased significantly the plasmid loss rate mainly by x.c.pv campestris. the lower efficiency of stabilization in x.c.pv manihotis was probably due to the incompatibility system b ...19921368368
genetics of xanthan production in xanthomonas campestris: the xana and xanb genes are involved in udp-glucose and gdp-mannose biosynthesis.the nucleotide sequence of a 3.4-kb ecori-psti dna fragment of xanthomonas campestris pv. campestris revealed two open reading frames, which were designated xana and xanb. the genes xana and xanb encode proteins of 448 amino acids (molecular weight of 48,919) and 466 amino acids (molecular weight of 50,873), respectively. these genes were identified by analyzing insertion mutants which were known to be involved in xanthan production. specific tests for the activities of enzymes involved in the b ...19921370280
expression of the xanthomonas campestris pv. vesicatoria hrp gene cluster, which determines pathogenicity and hypersensitivity on pepper and tomato, is plant inducible.the hrp gene cluster from xanthomonas campestris pv. vesicatoria determines functions necessary not only for pathogenicity on the host plants pepper and tomato but also for the elicitation of the hypersensitive reaction on resistant host and nonhost plants. transcriptional orientation and expression of the hrp loci were determined with hrp::tn3-gus fusions. in addition, expression of the hrp loci was studied by rna hybridization experiments. expression of the hrp genes was not detectable after g ...19921370664
amino acid and dna sequences of an extracellular basic protease of dichelobacter nodosus show that it is a member of the subtilisin family of proteases.a dna fragment encoding an extracellular basic protease (pi approximately 9.5) from dichelobacter nodosus, a gram-negative obligate anaerobe and the causative agent of ovine footrot, has been cloned and expressed in escherichia coli and sequenced. e. coli harbouring a plasmid with a 3-kb dna fragment containing the d. nodosus basic-protease gene exhibited proteolytic activity when tested on skim-milk plates. the sequence of the native basic protease isolated from d. nodosus was also determined b ...19921446666
the rhizobium meliloti pmi gene encodes a new type of phosphomannose isomerase.interspecific complementation of a xanthomonas campestris pv. campestris phosphomannose isomerase (pmi) mutant was used to isolate a cosmid from a genomic library of rhizobium meliloti 2011 carrying the pmi gene of this strain. subcloning experiments localized the coding region to a 2.0-kb sali-clai fragment. nucleotide sequence analysis of this fragment indicated the presence of two open reading frames (orfs), coding for 18- and 43-kda polypeptides. the analysis of the gene function by gene dis ...19921452036
disease development in ethylene-insensitive arabidopsis thaliana infected with virulent and avirulent pseudomonas and xanthomonas pathogens.the plant hormone ethylene has been hypothesized to play roles both in disease resistance and in disease susceptibility. these processes were examined by using isogenic virulent and avirulent bacterial pathogens and mutants of arabidopsis thaliana that were altered in ethylene physiology. ethylene-insensitive ein1 and ein2 mutants of arabidopsis were resistant to pseudomonas syringae pv. tomato made avirulent by the addition of the cloned avirulence genes avrrpt2, avrrpm1, or avrb; this suggests ...19921472714
hrp genes of pseudomonas solanacearum are homologous to pathogenicity determinants of animal pathogenic bacteria and are conserved among plant pathogenic bacteria.the majority of bacterial plant diseases are caused by members of three bacterial genera, pseudomonas, xanthomonas, and erwinia. the identification and characterization of mutants that have lost the abilities to provoke disease symptoms on a compatible host and to induce a defensive hypersensitive reaction (hr) on an incompatible host have led to the discovery of clusters of hrp genes (hypersensitive reaction and pathogenicity) in phytopathogenic bacteria from each of these genera. here, we repo ...19921472716
determinants of pathogenicity in xanthomonas campestris pv. vesicatoria are related to proteins involved in secretion in bacterial pathogens of of the model systems investigated for studying plant bacterial pathogenesis is xanthomonas campestris pv vesicatoria, the causal agent of bacterial spot disease of pepper and tomato. genes necessary for both basic pathogenicity and the induction of the hypersensitive response in resistant plants (hrp genes) were previously isolated from x. c. pv. vesicatoria and characterized genetically. as a first step toward functional analysis, part of the hrp gene cluster, making up several loci, was se ...19921472717
use of whey for production of exocellular polysaccharide by a mutant strain of xanthomonas campestris.growth and kinetics of the production of exocellular polysaccharide was studied in a mutant strain of xanthomonas campestris lac+ during cultivation in a submerged culture in a medium containing whey. the maximum production of the polymer was observed at the initial stage of the stationary growth phase of the culture. the mean production yield was about 1.4%. the results were comparable with those obtained during cultivation on a lactose medium.19921505865
molecular cloning, characterization and nucleotide sequence of the gene for secreted alpha-amylase from xanthomonas campestris pv. campestris.alpha-amylase (1,4-alpha-d-glucan glucanohydrolase, ec of apparent molecular mass 45 kda was secreted by xanthomonas campestris pv. campestris grown in medium containing starch or maltose. we isolated its structural gene from a recombinant lambda library and located it on a 2.7 kb dna fragment. nucleotide sequencing of the fragment revealed a potential orf encoding a protein of 475 amino acid residues, including a potential signal sequence of 35 amino acids. the signal processing site w ...19921527504
bioactive polymers: in vitro and in vivo study of controlled release neomycin.neomycin is coupled on xanthan-a polysaccharide of microbial biosynthesis produced by xanthomonas campestris-through ionic complexation. the kinetics of neomycin release, in vitro, at ph = 8.2 is studied. a controlled release of neomycin, following a zero order kinetics is observed, regardless of the eluent flow. neomycin complexed on xanthan, administered in a unique daily dose to patients suffering from dysentery in the 100 cases taken in study, has shown a high clinical efficiency as compared ...19921573555
rapid generation of directed and unmarked deletions in xanthomonas.we have devised a rapid four-step procedure for the generation of directed and unmarked chromosomal deletions in bacteria, based on the use of a novel cloning vector containing the bacillus subtilis sacb gene that encodes levansucrase and confers sucrose sensitivity, which can be used for counter-selection. using this technique, we describe the construction of a 6.5 kb directed and unmarked deletion in a phytopathogenicity region of the chromosome in xanthomonas campestris. this procedure allows ...19921574006
genetic and molecular analysis of a cluster of rpf genes involved in positive regulation of synthesis of extracellular enzymes and polysaccharide in xanthomonas campestris pathovar campestris.the cosmid clone pij3020 containing dna from the plant pathogenic bacterium xanthomonas campestris pathovar campestris has previously been shown to complement a non-pathogenic mutant defective in synthesis of extracellular enzymes. the dna cloned in pij3020 was analysed by mutagenesis with tn5 and tn5lac and by nucleotide sequencing. the results indicate that this region of the genome contains a cluster of genes, mutation in any of which results in failure of the enzymes and extracellular polysa ...19911645442
identification of two fructose transport and phosphorylation pathways in xanthomonas campestris pv. campestris.fructose was shown to be phosphorylated by a specific phosphoenolpyruvate-dependent phosphotransferase system (pts) in xanthomonas campestris pv. campestris. transposon mutagenesis of x. campestris was performed and two mutants affected in growth on fructose were isolated. both mutants were deficient in pts activity. comparison of the rate of uptake and phosphorylation of fructose in the wild-type and in the mutant strains revealed the presence of a second fructose permeation and phosphorylation ...19911650911
use of cloned dna methylase genes to increase the frequency of transfer of foreign genes into xanthomonas campestris pv. vitro-packaged cosmid libraries of dna from the bacterium xanthomonas campestris pv. malvacearum were restricted 200- to 1,000-fold when introduced into mcr+ strains of escherichia coli compared with restriction in the mcr- strain hb101. restriction was predominantly associated with the mcrbc+ gene in e. coli. a plasmid (pufr052) encoding the xmai and xmaiii dna methylases was isolated from an x. campestris pv. malvacearum library by a screening procedure utilizing mcr+ and mcr- e. coli strai ...19911655710
fructose catabolism in xanthomonas campestris pv. campestris. sequence of the pts operon, characterization of the fructose-specific xanthomonas campestris pv. campestris, fructose is transported and phosphorylated into fructose 1-phosphate through a phosphoenolpyruvate-dependent phosphotransferase system. the nucleotide sequence of the frua gene encoding the phosphotransferase system permease specific of fructose (eiifru) was determined. the fructose 1-phosphate produced by the phosphotransferase system is phosphorylated into fructose 1,6-bisphosphate by a 1-phosphofructokinase. this enzyme was characterized and the corre ...19911655739
location and cloning of the ketal pyruvate transferase gene of xanthomonas campestris.genes required for xanthan polysaccharide synthesis (xps) are clustered in a dna region of 13.5 kb in the chromosome of xanthomonas campestris. plasmid pchc3 containing a 12.4-kb insert of xps genes has been suggested to include a gene involved in the pyruvylation of xanthan gum (n.e. harding, j.m. cleary, d.k. cabañas, i. g. rosen, and k. s. kang, j. bacteriol. 169:2854-2861, 1987). an essential step toward understanding the biosynthesis of xanthan gum and to enable genetic manipulation of xant ...19911657892
environmentally regulated algd promoter is responsive to the camp receptor protein in escherichia coli.the environmentally activated algd promoter of pseudomonas aeruginosa has been shown to be influenced by dna supercoiling. it is believed that protein-induced bending or looping is required for this activation. we studied the role of escherichia coli camp-crp on algd promoter activation in e. coli and show that a functional crp is required for this activation. we also demonstrate that the algd promoter is sensitive to glucose repression both in e. coli and p. aeruginosa. deletion of a putative c ...19911665196
xanthomonas campestris contains a cluster of hrp genes related to the larger hrp cluster of pseudomonas solanacearum.all xanthomonas campestris pathovars tested contain dna which hybridizes to the large hrp gene cluster of pseudomonas solanacearum (c.a. boucher, f. van gijsegem, p.a. barberis, m. arlat, and c. zischek, j. bacteriol. 169:5626-5632, 1987). clones carrying these sequences were isolated from genomic libraries of x. campestris pvs. campestris and vitians. mutagenesis of the corresponding genomic regions of both pathovars gave strains defective in both pathogenicity and hypersensitive response induc ...19911666525
distribution of alginate gene sequences in the pseudomonas rrna homology group i-azomonas-azotobacter lineage of superfamily b procaryotes.chromosomal dna from group i pseudomonas species, azotobacter vinelandii, azomonas macrocytogens, xanthomonas campestris, serpens flexibilis, and three enteric bacteria was screened for sequences homologous to four pseudomonas aeruginosa alginate (alg) genes (alga, pmm, algd, and algr1). all the group i pseudomonas species tested (including alginate producers and nonproducers) contained sequences homologous to all the p. aeruginosa alg genes used as probes, with the exception of p. stutzeri, whi ...19901689562
cloning of genes involved in negative regulation of production of extracellular enzymes and polysaccharide of xanthomonas campestris pathovar campestris.a recombinant plasmid pij3079 contains dna sequences from xanthomonas campestris pv campestris involved in coordinate negative regulation of production of the extracellular enzymes protease, endoglucanase, amylase and polygalacturonate lyase, and extracellular polysaccharide (eps). wild-type bacteria harbouring pij3079 and therefore carrying extra copies of the gene(s) therein showed reduced enzyme and eps production and reduced aggressiveness to plants. localised tn5 mutagenesis of the correspo ...19901700268
[evaluation of culture media for detecting the starch hydrolysis reaction in pathovars of xanthomonas campestris].sixty strains of different pathovars of xanthomonas campestris have been tested for the evaluation of various starch agars and compounds of starch degradation on six media: soluble starch, potato insoluble starch, corn insoluble starch, potato amylopectin, corn amylopectin and potato amylose. the purpose of the present investigation was the selection of the most suitable medium for the visualization of the starch hydrolysis test, presenting this reaction as a distinct character between pathovars ...19911726127
dna probes for detection of copper resistance genes in xanthomonas campestris pv. vesicatoria.the copper resistance (cur) genes encoded on pxv10a, a 190-kb plasmid in xanthomonas campestris pv. vesicatoria xv10, were isolated on a 44-kb cosmid clone designated pcur1. tn5 mutagenesis of pcur1 indicated that a 4.0-kb region was required for copper resistance. three restriction fragments located within the 4.0-kb region demonstrated high specificity for the cur genes present in x. campestris pv. vesicatoria and will be useful in monitoring the presence of these genes in the environment.19911768118
a gene from xanthomonas campestris pv. vesicatoria that determines avirulence in tomato is related to avrbs3.strains of xanthomonas campestris pv. vesicatoria that were avirulent in tomato leaves but virulent in pepper leaves were identified. a cloned gene, avrbsp, from one of the strains, xv 87-7, converted a virulent strain in tomato to avirulent in tomato. a 1.7-kb subclone containing the avirulence gene cross-hybridized with the avirulence gene, which determines race 1 within the pepper group of strains (avrbs3). however, the two avirulence genes differ in their biological activity. the base sequen ...19911804405
[production of xanthan gums].xanthomonas campestris was investigated in 70 samples of infected plants in the neighbourhood of luján, province of buenos aires, between february and august, 1990. the production of xanthan gum was determined from 50 strains of xanthomonas campestris, as well as the conversion efficiency of substrate concentration into gum and the number of colony forming units (cfu) of xanthomonas campestris/ml of broth culture. the highest number of strains producing extracellular polysaccharide was obtained ...19911815272
complete nucleotide sequence of filamentous phage cf1c from xanthomonas campestris pv. citri. 19911840658
a series of wide-host-range low-copy-number vectors that allow direct screening for recombinants.a series of controlled expression vectors was constructed based on the wide-host-range plasmid pmmb66eh. some of these new vectors code for the alpha-peptide of beta-galactosidase and allow the direct screening of recombinant clones by inactivation of alpha-complementation. the bla gene was replaced in some plasmids by the cat gene of tn9 coding for chloramphenicol resistance, extending the use into beta-lactam-resistant strains. they all feature either the tac or taclac (tac-lac uv5 in tandem) ...19911847347
isolation and characterization of insertion sequence elements from gram-negative bacteria by using new broad-host-range, positive selection vectors.on the basis of an rsf1010-derived broad-host-range vector, three different systems which enable positive detection and isolation of insertion sequence (is) elements from gram-negative bacteria were constructed. vectors psup104-phes, psup104-rpsl, and psup104-sac were used successfully in a number of rhizobium strains and in xanthomonas campestris. more than 20 different is elements were isolated and characterized. the 16 is elements from rhizobium meliloti were further used to characterize vari ...19911847366
conservation of xcp genes, involved in the two-step protein secretion process, in different pseudomonas species and other gram-negative bacteria.the two-step protein secretion pathway in pseudomonas aeruginosa is dependent on the xcp genes. we investigated whether a similar secretion mechanism is present in non-pathogenic pseudomonas spp. and in other gram-negative bacteria. the plant growth stimulating pseudomonas strains p. putida wcs358, p. fluorescens wcs374 and pseudomonas b10 appeared to secrete proteins into the extracellular medium. southern hybridization experiments showed the presence of xcp genes in these strains and also in o ...19911921977
site-specific recombination promoted by a short dna segment of plasmid r1 and by a homologous segment in the terminus region of the escherichia coli chromosome.a short dna segment located in the kanamycin resistance region of plasmid r1 promotes site-specific recombination and plasmid maintenance. this segment has been reduced to 100 bp and subsequently to 44 bp without losing these properties. it can recombine with a similar segment located in the terminus region of the escherichia coli chromosome. it is proposed that this recombination is responsible for the plasmid maintenance properties of the r1 segment. the chromosomal site has been isolated; it ...19911931823
expression of the avirulence gene avrbs3 from xanthomonas campestris pv. vesicatoria is not under the control of hrp genes and is independent of plant factors.the avirulence gene avrbs3 from xanthomonas campestris pv. vesicatoria pepper race 1 is responsible for the induction of a race-specific hypersensitive reaction in resistant pepper cultivars. a dna region of 3.7 kb, containing several open reading frames and an internal repetitive region, was shown previously to be necessary for avirulence activity (u. bonas, r. e. stall, and b. staskawicz, mol. gen. genet. 218:127-136, 1989). the promoter of avrbs3 was identified by using gene fusions to beta-g ...19911938914
induction of the alka gene of escherichia coli in gram-negative bacteria.a broad-host-range plasmid containing a fusion of the alka and lacz genes of escherichia coli was introduced into various aerobic and facultative gram-negative bacteria--33 species belonging to 19 genera--to study the induction of expression of the alka gene by alkylating agents. the bacteria included species of the families enterobacteriaceae, pseudomonadaceae, rhizobiaceae, vibrionaceae, neisseriaceae, rhodospirillaceae, and azotobacteraceae. results obtained show that all bacteria tested, exc ...19911938974
structural characterization of protein secretion genes of the bacterial phytopathogen xanthomonas campestris pathovar campestris: relatedness to secretion systems of other gram-negative bacteria.the nucleotide sequence was determined of a 5.3 kb region of the xanthomonas campestris pathovar campestris genome carrying a gene cluster encoding protein secretion and pathogenicity functions. a putative promoter sequence and five open reading frames (orf) which may be part of an operon were revealed. the five predicted primary translation products comprise 531, 390, 147, 169 and 138 amino acids with mr values of 58,854, 42,299, 15,548, 18,214 and 15,108 respectively. a sixth, partial orf is a ...19911944223
expression of the reca gene of escherichia coli in several species of gram-negative bacteria.a broad host range plasmid containing an operon fusion between the reca and lacz genes of escherichia coli was introduced into various aerobic and facultative gram-negative bacteria-30 species belonging to 20 different genera - to study the expression of the reca gene after dna damage. these included species of the families enterobacteriaceae, pseudomonadaceae. rhizobiaceae, vibrionaceae, neisseriaceae, rhodospirillaceae and azotobacteraceae. results obtained show that all bacteria tested, excep ...19912038310
influence of acetyl and pyruvate substituents on the solution properties of xanthan polysaccharide.xanthan, an exocellular polysaccharide produced by the plant pathogenic bacterium xanthomonas campestris has been the subject of considerable interest in recent years because of its unusual rheological properties in solution ('weak gel') and consequent range of applications. the polymer consists of a cellulosic backbone with trisaccharide side chains linked to alternate backbone residues; acetyl and pyruvate substituents are carried in variable amounts on these side chains. in this study a serie ...19902078534
the melanin operon of streptomyces antibioticus: expression and use as a marker in gram-negative bacteria.the melc operon of streptomyces antibioticus contains two genes, melc1 and melc2, necessary for the production of melanin pigment. we transferred the coding sequence of melc1 and melc2 to escherichia coli plasmid pmtl23 such that its transcription was under the control of the lac promoter and melc1 was translationally fused to the lacz alpha fragment. e. coli cultures containing this plasmid, pif413, produced melanin after overnight incubation on 2yt agar supplemented with 0.1 mm cucl2, 0.36 mm ...19902107124
construction of lactose-utilizing xanthomonas campestris and production of xanthan gum from whey.xanthomonas campestris pv. campestris possesses a low level of beta-galactosidase and therefore is not able to grow and produce significant amounts of xanthan gum in a medium containing lactose as the sole carbon source. in this study, a beta-galactosidase expression plasmid was constructed by ligating an x. campestris phage phi lo promoter with pkm005, a cole1 replicon containing escherichia coli laczy genes and the lpp ribosome-binding site. it was then inserted into an incp1 broad-host-range ...19902111116
first isolation of xanthomonas campestris from the blood of a chinese woman.xanthomonas campestris isolated from the blood of a patient with a fever was first reported. xanthomonas campestris is a bacterium that can cause black rot of some vegetables, such as rape. chinese cabbage, etc. human infection due to x. campestris has not been reported so far. the characteristics of this organism, including morphology, staining, physiology and biochemistry were studied. we believe that x. campestris is also one of the opportunistic pathogens, which can infect compromised host.19902118062
identification and dna sequence of a pathogenicity gene of xanthomonas campestris pv. campestris.a region of xanthomonas campestris pv. campestris dna containing at least two pathogenicity genes was identified. mutants in one gene were clearly reduced in pathogenicity while mutants in the other were only moderately reduced. both classes of mutants were prototrophic and motile, and had wild-type levels of extracellular enzymes and extracellular polysaccharide. they also grew in vitro and in planta at the same rate as the wild type. experiments involving one of the clear pathogenicity mutants ...19902135951
characterization of is476 and its role in bacterial spot disease of tomato and pepper.is476 is an endogenous insertion sequence present in copper-tolerant strains of xanthomonas campestris pv. vesicatoria. sequence analysis has revealed that the element is 1,225 base pairs in length, has 26-base-pair inverted repeats, and causes a 4-base-pair target site duplication upon insertion into the avirulence gene avrbs1. comparison of the full-length sequence with sequences in the national biomedical research foundation and national institutes of health data bases showed that one of the ...19902152895
a plant-inducible gene of xanthomonas campestris pv. campestris encodes an exocellular component required for growth in the host and hypersensitivity on nonhosts.using tn4431, a transposon that allows transcriptional fusions to a promoterless luciferase (lux) operon, we have isolated a nonpathogenic mutant of xanthomonas campestris pv. campestris, i.e., js111, that does not incite any of the black rot symptoms on all tested cruciferous host plants (j. j. shaw, l. g. settles, and c. i. kado, mol. plant microbe interact. 1:39-45, 1988). in the study reported here, we determined that in contrast to the wild-type strain, js111 is unable to induce a hypersens ...19902168373
a xanthomonas campestris pv. campestris protein similar to catabolite activation factor is involved in regulation of phytopathogenicity.a dna fragment from xanthomonas campestris pv. campestris that partially restored the carbohydrate fermentation pattern of a cya crp escherichia coli strain was cloned and expressed in e. coli. the nucleotide sequence of this fragment revealed the presence of a 700-base-pair open reading frame that coded for a protein highly similar to the catabolite activation factor (cap) of e. coli (accordingly named clp for cap-like protein). an x. campestris pv. campestris clp mutant was constructed by reve ...19902170330
identification of a pathogenicity locus in xanthomonas campestris pv. vesicatoria.mutants of a tomato strain of xanthomonas campestris pv. vesicatoria (xcv), causal agent of bacterial spot of tomato and pepper, were produced using the transposon tn5 carried in the suicide plasmid pgs9. one prototrophic mutant, m461, was isolated which caused no visible reaction on tomato or pepper, but maintained the wild-type ability to induce a hypersensitive reaction (hr) on tobacco. this mutant showed similar growth characteristics to the wild-type in culture, but growth in planta was red ...19902177139
a multipurpose broad host range cloning vector and its use to characterise an extracellular protease gene of xanthomonas campestris pathovar campestris.a multipurpose broad host range plasmid, pij3200, was constructed by inserting the polylinker-containing 445 bp pvuii fragment of bluescript m13 into the ecori site of the cosmid plafr1. using this vector a protease gene of xanthomonas campestris pathovar campestris, previously cloned in the recombinant plasmid pij3070, was located by deletion to a 2.2 kb dna region. sequencing of the protease gene revealed an open reading frame encoding a 580 amino acid polypeptide with molecular weight of 57,0 ...19902187155
use of oligonucleotide probes to identify members of two-component regulatory systems in xanthomonas campestris pathovar campestris.two-component regulatory systems comprising a sensor and a regulator protein, both with highly conserved amino acid domains, and commonly genetically linked, have been described in a range of bacterial species and are involved in sensing environmental stimuli. we used two oligonucleotide probes matching the postulated coding regions for domains of sensor and regulator proteins respectively in xanthomonas campestris pathovar campestris (xcc) to identify possible two-component regulatory systems i ...19902233675
conserved repetition in the ice nucleation gene inax from xanthomonas campestris pv. translucens.the nucleotide sequence was determined for the bacterial ice nucleation gene, inax, from xanthomonas campestris pathovar translucens x56s. comparison of the nucleotide sequence of inax to the previously characterized ice nucleation genes, inaz from pseudomonas syringae s203, inaw from pseudomonas fluorescens ms1650, and icee from erwinia herbicola m1 revealed a 65.8%, 67.8%, and 68.8% homology, respectively. within the internal, repetitive domain of the translated product of inax are 153 consecu ...19902259339
numerical analysis of 295 phenotypic features of 266 xanthomonas strains and related strains and an improved taxonomy of the extensive phenotypic description and an improved classification and nomenclature of the genus xanthomonas are presented. a total of 266 strains obtained from different geographical areas, including representative strains of all species of the genus xanthomonas and most pathovars of xanthomonas campestris, as well as strains which might be genetically related to the genus xanthomonas, were examined for 295 morphological, biochemical, and physiological features. similarities among the strains w ...19902275852
extracellular proteases from xanthomonas campestris pv. campestris, the black rot pathogen.two proteases (prt1 and prt2) were fractionated from culture supernatants of wild-type xanthomonas campestris pv. campestris by cation-exchange chromatography on sp-5pw. inhibitor experiments showed that prt 1 was a serine protease which required calcium ions for activity or stability or both and that prt 2 was a zinc-requiring metalloprotease. prt 1 and prt 2 showed different patterns of degradation of beta-casein. the two proteases comprised almost all of the extracellular proteolytic activity ...19902285313
cloning and analysis of a 35.3-kilobase dna region involved in exopolysaccharide production by xanthomonas campestris pv. campestris.cosmid clones able to restore exopolysaccharide production in possibly insertion sequence element-induced surface mutants of xanthomonas campestris pv. campestris were isolated. by fragment-specific tn5-lac mutagenesis of one of the cosmids, pxcb1002, a new dna region which is involved in exopolysaccharide biosynthesis and which is organized into at least 12 complementation groups was identified.19902332409
small, stable shuttle vectors for use in xanthomonas.plasmids from three broad-host-range (bhr) incompatibility groups (inc) were evaluated for use as cloning vectors in xanthomonas campestris pv. malvacearum (xcm), the causal agent of bacterial blight of cotton. the incp vectors plafr3 and pvk102 could not be introduced into xcm at a significant frequency (less than 1 x 10(-10] and incq vectors such as pkt210 were unstable in their maintenance and tended to delete cloned inserts. incw vectors such as psa747 also were lost readily from xcm in the ...19902341039
nucleotide sequence of the engxca gene encoding the major endoglucanase of xanthomonas campestris pv. campestris.the nucleotide sequence of the gene (engxca) encoding the major extracellular endoglucanase (engxca) of the phytopathogenic bacterium xanthomonas campestris pv. campestris (x. c. campestris) was determined and compared with the n-terminal amino acid (aa) sequence of the purified enzyme. an open reading frame of 1479 bp encoding 493 aa was identified, of which the n-terminal 25 aa represent a potential signal peptide. determination of the exact position of a tn5 insertion within engxca, which did ...19902373365
widespread distribution and fitness contribution of xanthomonas campestris avirulence gene avrbs2.disease-resistance genes introduced into cultivated plants are often rendered ineffective by the ability of pathogen populations to overcome host resistance. the bacterial pathogen xanthomonas campestris pathovar vesicatoria causes bacterial spot disease of tomato and pepper, and this pathogen has been shown to overcome disease resistance in pepper (capsicum annuum) by evading the recognition and defence response of the host plant. numerous resistance genes to bacterial spot have been identified ...19902374611
characterization of filamentous bacteriophage phi lf from xanthomonas campestris pv. campestris.a filamentous phage, phi lf, which specifically infects xanthomonas campestris pv. campestris was isolated. the phage particle measured 1,000 (+/- 200) x 8 nm. it formed turbid plaques of about 1 mm in diameter. during multiplication, the progeny virions extruded into the medium without retarding host cell growth. stocks were stable for 6 months at 4 degrees c and survived treatment at 80 degrees c for 10 min. treatment with chloroform, ethanol or acetone completely destroyed infectivity; ethyl ...19902391505
a simple method for maintaining xanthomonas campestris pv. citri.a typical colony of each of strains xw17, xw45, xw47, xw82, xw86, xw118, and xw138 of xanthomonas campestris pv. citri was streaked onto nutrient agar, gy agar, minimal agar, and semi-enriched minimal agar plates, respectively. the agar plates, after incubated at 30 degrees c for 2-4 days, were inverted and stored at 4 degrees c in darkness. all of the x. campestris pv. citri strains retained their viability for at least 26 weeks on the semi-enriched minimal agar plates; whereas, cultures of the ...19902394191
genetic and structural characterization of the avirulence gene avrbs3 from xanthomonas campestris pv. vesicatoria.the avirulence gene avrbs3 from xanthomonas campestris pv. vesicatoria was cloned and found to be localized on a self-transmissable plasmid. genetic analysis of an avrbs3 insertion mutation revealed that avrbs3 constitutes a single locus, specifying the resistant phenotype on pepper plants. southern blot experiments showed that no dna sequences homologous to avrbs3 were present in other races of x. c. pv. vesicatoria, which are unable to induce a hypersensitive reaction on ecw-30r. however, the ...19892550761
transposable elements for efficient manipulation of a wide range of gram-negative bacteria: promoter probes and vectors for foreign genes.we describe here the construction and use of a series of modified transposons based on the insertion sequence is1. like their parent, omegon-km [fellay et al., gene 76 (1989) 215-226], these elements permit efficient insertional mutagenesis of a variety of gram-negative bacteria. the presence of a functional pbr322 origin of replication within the transposable element facilitates subsequent cloning of the mutated gene. the omegon-km system was previously shown to function in pseudomonas putida, ...19892559879
identification and nucleotide sequence of attachment site of the cflt filamentous phage from xanthomonas campestris pv. has been reported that the attachment site on the phage attp is located from 69.2 to 73.8 min on cflt rf dna. kpni and psti were used, which cut respectively at 67.2 and 72.6 min of cflt rf dna. a 0.54 kb fragment containing attp was obtained. for isolation of the right (attr) and left (attl) junctions of prophage and host chromosomal dna, lysogen dna was digested with hindiii and used to prepare a recombinant plasmid library. with cflt rf dna as a probe, three types of recombinant plasmids r ...19892605976
monoclonal antibodies reacting with the exopolysaccharide xanthan from xanthomonas campestris.we have prepared murine hybridomas secreting monoclonal antibodies against the exopopolysaccharide xanthan from xanthomonas campestris pv. campestris 646 after fusing nso myeloma cells and spleen cells from balb/c mice immunized with xanthan. four hybridomas, secreting antibodies designated a6 (igm kappa), b3 (igm kappa), d1 (igm kappa), and d3 (igg2a kappa), were selected for further studies. all antibodies reacted with a range of different xanthans. competition studies using variants of the ex ...19892621443
a translational enhancer derived from tobacco mosaic virus is functionally equivalent to a shine-dalgarno sequence.when present at the 5' end of mrnas, the untranslated leader sequence (omega) of tobacco mosaic virus rna significantly enhances translation in eukaryotes and prokaryotes. we have tested a deletion derivative of the omega sequence, omega delta 3, for its enhancing ability on gene constructs in which the ribosomal binding site was either present or deleted, in several gram-negative bacterial species including escherichia coli, agrobacterium tumefaciens, xanthomonas campestris pv. vitians, erwinia ...19892643095
a new protein subunit k for rna polymerase from xanthomonas campestris pv. oryzae.during the purification of rna polymerase from xanthomonas campestris pv. oryzae, a new subunit named k was found to be associated with this enzyme. the removal of subunit k from holoenzyme by deae-cellulose column chromatography results in a decrease in specific activity of the enzyme. the readdition of subunit k to subunit k-depleted holoenzyme results in restoration of enzymatic activity. subunit k increase the activity of rna polymerase; the activation was in proportion to the concentration ...19892647734
genetic and biochemical analysis of protein export from xanthomonas campestris.xanthomonas campestris pv. campestris, a gram-negative phytopathogen, produces a number of extracellular enzymes which can degrade components of the host plant cell. some non-pathogenic mutants, derived by chemical mutagenesis, were found to be defective in the export but not the synthesis of a number of these enzymes. the pathogenicity and export lesions in one such mutant, strain 8288, could be complemented by a cosmid clone pij3000 from the xanthomonas library. mutagenesis of pij3000 with the ...19892693461
kinetics of xanthan production when nh3-n limits biomass synthesis and glucose limits polysaccharide synthesis.the bacterium xanthomonas campestris, which synthesizes the commercially important polysaccharide xanthan, was grown aseptically in 1.2 l fermenters using semicontinuous cell culture technique (d' = 0.0035 h-1). the effects of carbon-substrate concentration on xanthan production were investigated at three initial glucose concentrations (go = 15, 20, 25 g/l). cell biomass synthesis was nitrogen-limited by use of a chemically defined medium that contained nh3-n as the sole nitrogen source at a con ...19892733412
[characterization of xanthomonas campestris pv. cucurbitae, causal agent of the bacterial spot of squash].bacterial leaf spot of squash was characterized for the first time in argentina. cultural, physiological, morphological and cross-infection tests on cucurbitaceae showed that the pathogen was xanthomonas campestris pv. cucurbitae (bryan) dye. the bacterium isolated from winter squash proved pathogenic for pumpkin, winter squash, cucumber and watermelon but no for muskmelon.19892748850
analysis of pectate lyases produced by soft rot bacteria associated with spoilage of vegetables.isoelectric focusing (ief) profiles of pectate lyases (pls) produced by five different groups of soft rot bacteria were analyzed by using the combined techniques of thin-layer polyacrylamide gel ief and agarose-pectate overlay activity staining. four strains of soft rot erwinia spp. produced three or more pl isozymes. all of eight pseudomonas viridiflava strains examined produced one single pl with a pi of 9.7. all 10 of pseudomonas fluorescens strains produced two pls; the major one had a pi of ...19892764574
host range and particle morphology of some bacteriophages affecting pathovars of xanthomonas bacteriophages active against different pathovars of xanthomonas campestris were isolated from naturally infected plant material. all showed polyhedral heads and could be separated into two morphological groups according to their tail structures. phages active against x. campestris pv. cucurbitae (xcu-p1 and xcu-p3) and x. campestris pv. holcicola (xhol-p1) were described for the first time. ninety nine bacterial strains belonging to 5 genera (xanthomonas, pseudomonas, agrobacterium, clavi ...19892803638
pseudomonas solanacearum genes controlling both pathogenicity on tomato and hypersensitivity on tobacco are clustered.a plafr3 cosmid clone designated pvir2 containing a 25-kilobase (kb) dna insert was isolated from a wild-type pseudomonas solanacearum gmi1000 genomic library. this cosmid was shown to complement all but one of the nine tn5-induced mutants which have been isolated after random mutagenesis and which have lost both pathogenicity toward tomato and ability to induce hypersensitive reaction (hr) on tobacco (hrp mutants). the insert is colinear with the genome and provides restoration of the hr-induci ...19872824440
the avirulence gene avrbs1 from xanthomonas campestris pv. vesicatoria encodes a 50-kd protein.a gene cloned from xanthomonas campestris pv. vesicatoria race 2, avrbs1, specified avirulence on pepper cultivars containing the resistance gene bs1. a series of exonuclease iii deletions were made on a 3.2-kbp dna fragment that determined full avirulence activity, observed as hypersensitive response (hr) induction. the deletion products were subcloned into the broad host range cloning vector plafr3, conjugated into a virulent x. c. pv. vesicatoria race 1 strain, 82-8, and scored for their abil ...19882979910
loss of sigma-factor of rna polymerase of xanthomonas campestris pv. oryzae during phage xp10 infection.ten min after infection of xanthomonas campestris pv. oryzae by phage xp10, a sharp decrease in the activity of the host rna polymerase was observed. host rna polymerase from phage-infected and uninfected cells was purified, and their properties were compared. the enzyme from uninfected cells contained four polypeptides with mr = 155,000, 155,000, 93,000, and 37,000, respectively, and assembled with a stoichiometry of alpha 2 beta beta' sigma. the enzyme from infected cells lacked the sigma-subu ...19863020043
cloning and regulation of erwinia herbicola pigment genes.the genes coding for yellow pigment production in erwinia herbicola eho10 (atcc 39368) were cloned and localized to a 12.4-kilobase (kb) chromosomal fragment. a 2.3-kb avai deletion in the cloned fragment resulted in the production of a pink-yellow pigment, a possible precursor of the yellow pigment. production of yellow pigment in both e. herbicola eho10 and pigmented escherichia coli clones was inhibited by glucose. when the pigment genes were transformed into a cya (adenylate cyclase) e. coli ...19863023282
genetic and physical analyses of a cluster of genes essential for xanthan gum biosynthesis in xanthomonas campestris.xanthomonas campestris produces copious amounts of a complex exopolysaccharide, xanthan gum. nonmucoid mutants, defective in synthesis of xanthan polysaccharide, were isolated after nitrosoguanidine mutagenesis. to isolate genes essential for xanthan polysaccharide synthesis (xps), a genomic library of x. campestris dna, partially digested with sali and ligated into the broad-host-range cloning vector prk293, was constructed in escherichia coli. the pooled clone bank was conjugated en masse from ...19873034868
clustering of mutations blocking synthesis of xanthan gum by xanthomonas campestris.mutations that block the synthesis of xanthan gum by xanthomonas campestris b1459s-4l-ii were isolated as nonmucoid colonies after treatment with ethyl methanesulfonate. complete libraries of dna fragments from wild-type x. campestris were cloned into escherichia coli by using a broad-host-range cosmid vector and then transferred into each mutant strain by conjugal mating. cloned fragments that restored xanthan gum synthesis (xgs+; mucoidy) were compared according to restriction pattern, dna seq ...19873038845
[numerical taxonomy of several pathovars of xanthomonas campestris].numerical methods were used in order to study the relationships between 26 bacterial strains of 18 pathovars of xanthomonas campestris according to 115 morphological, cultural, physiological and pathogenic characteristics. similarity for each pair of cultures was calculated by simple matching coefficient. using single linkage method of association, the strains fall into a major group formed by pathovars undulosa, translucens, secalis, hordei, pelargonii, hederae, pruni, cucurbitae, zinniae, citr ...19873077325
monoclonal antibodies in identifying neisseria gonorrhoeae: cautionary note. 19873123361
glucose metabolism in xanthomonas campestris and influence of methionine on the carbon flow.the glucose flow in xanthomonas campestris was investigated with radio-labelled glucose and by enzymological studies. only 7% of the radioactivity was incorporated into the cell material, but 41% was oxidized to carbon dioxide and 28% transformed to xanthan. up to 16% of cell dry weight consisted of the polysaccharide glycogen. in the presence of 2.7 mm methionine, which is an inhibitor of xanthan formation, increased carbon dioxide formation (51%) occurred. this increase was in accordance with ...19883148363
[lysogeny of strains of xanthomonas campestris and their variants]. 19873150487
characterization of a spontaneously segregating cf16-v1 lysogen of xanthomonas campestris pv. citri.filamentous phage cf16 undergoes a unique neolysogenic infectious cycle in xanthomonas campestris pv. citri and generates stable lysogens. in contrast, we have isolated a distinctive unstable lysogen, designated lw. this new lysogen segregated spontaneously into three nonparental types, each with a unique combination of colony morphology, phage-producing capacity, and phage genome content. in a given population of lw lysogens the segregation frequency of these types varied randomly with drastic ...19883182235
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