| in vitro studies on bacterial colonization. the effects of beta-lactam antibiotics on the growth of escherichia coli and pseudomonas aeruginosa in mixed culture. | many cases of pseudomonas aeruginosa infection are considered to be secondary superinfections, resulting from bacterial colonization. such cases of superinfection with p. aeruginosa developing after administration of cephalosporin or penicillin are offering serious clinical problems. to make a fundamental analysis of the development of such superinfections, attempts were made to compare the growth patterns of escherichia coli and p. aeruginosa in pure and mixed cultures and to determine the effe ... | 1979 | 120484 |
| [differentiation of nonspecific serological reactions in brucellosis]. | differentiation of non-specific agglutination was performed by the complement binding reaction, coombs' reaction, hajdu reaction, the surface fixation and agglutination reaction and the reaction of complement binding with heterologic antigens. for that purpose the following were used: 1) serums--antiglobulin against cattle globulin, 5720 serum of various animals which had manifested non-specific agglutination with brucella antigen and brucella serums of experimentally infected sheep, of naturall ... | 1979 | 120633 |
| [aquatic myxobacteria as indicators in the evaluation of drinking water quality (author's transl))]. | aquatic myxobacteria were shown to be good indicators of surface contamination of drinking water, or water filtered by an inadequate soil profile, both in experiments with sterilized or biologically active soil profiles, resp., and in actual comparison data obtained in practical drinking water analyses. in experimental investigations with artificial profiles, aquatic myxobacteria were retained to a considerably greater degree than e. coli or p. fluorescens due to stronger forces of adhesion. in ... | 1979 | 120649 |
| [examinations about the mutual influence of bacteria in aqueous medium with minimal nutritive substances (author's transl)]. | experiments were done about the behaviour of 5 different strains of st. aureus (= st), e. coli (= ec), se. marcescens (= se) and p. aeruginosa (= pa) in aqua bidest. at 30 degress c and 40 degrees c. in the first part the smallest quantities of standard-i-broth (merck) were evaluated where the diverse bacteria-species are able to grow; it was found at 30 degrees c (in parenthesis at 40 degrees c): st. aureus 1750 (3750) microgram/dl, e. coli 1000 (1750) microgram/dl, se. marcescens 2.5 (125) mic ... | 1979 | 120653 |
| [examinations on the behaviour of grampositive and gramnegative bacteria in aqua bidest and tap-water at different initial colony counts and different temperatures (author's transl)]. | experiments were done about the behaviour of 5 different strains of staph. aureus, strept. faecalis, e. coli, ser. marcescens and p. aeruginosa in aqua bidest and sterile tap water at 20 degrees c, 30 degrees c and 40 degrees c. the behaviour of 3 different initial colony counts in each case was examined. colony forming units (cfu) were evaluated at the beginning and after 1, 2, 4, 6 and 24 h. cfu were reduced at staph. aureus and e. coli in aqua bidest and tap water not earlier than after 4 h, ... | 1979 | 120654 |
| streptomycin sensitivity of ribosomes isolated from a streptomycin-producing streptomyces griseus. | the streptomycin sensitivity of ribosomes derived from a streptomycin-producing streptomyces griseus was examined in a polyuridylic acid directed 14c-phenylalanine incorporating system. in order to get reproducible results it is essential to use cell-free extracts which do not inactivate streptomycin. this condition can be fulfilled by the combination of washed ribosomes of the streptomycin-producing strain and the 110 000 g supernatant of the streptomycin-nonproducing variant of s. griseus, bec ... | 1979 | 120678 |
| an improved method for detecting foreign dna in plasmids of escherichia coli. | | 1979 | 120689 |
| reconstitution of binding protein-dependent ribose transport in spheroplasts of escherichia coli k-12. | | 1979 | 120701 |
| effect of osmotic stabilizers on radiometric detection of cell wall-damaged bacteria. | the effect of osmotic stabilizers on the 14co2-dependent radiometric detection of cell wall-damaged escherichia coli, staphylococcus aureus, and pseudomonas aeruginosa was studied in bactec 14c-labeled blood culture medium. the organisms were previously exposed to cefamandole or carbenicillin at 63 to 80% of the minimum inhibitory concentrations. the addition of 10% sucrose, 2.2% glycerol, and 2.2% ethylene glycol to the medium failed to reduce the time required for detection and diminished the ... | 1979 | 120874 |
| salmonella choleraesuis proteins and their relation to proteins from bacteria of heterologous sero-groups. | a diversity of proteins was identified in the material isolated from s. choleraesuis with the help of sera prepared in rabbits with this material. the sera displayed, in agar-gel diffusions, numerous superimposed precipitation lines against proteins from: salmonellae, shigellae and e. coli. in contrast to proteins from s. paratyphi c, sharing identical identical 'o' 'factors, the serological activity of the s. choleraesuis proteins was impaired by heating. the immunochemical analysis of the sera ... | 1979 | 120926 |
| [suitability of chemical neutralizers applied for disinfection control on commercial animal husbandry objects]. | a study on the effect of various neutralizers of the most widely spread means of disinfection applied in animal rearing was made. for that purpose twin lecytine was tested for quadruple ammonium compounds: twin--for phenolic compounds, natrium thiosulfate--for iodoformium and chlor-containing compounds, as well as natrium sulfite--for formalin. as test micro-organisms were used staph. aureus sg 511, e. coli 078, and ps. aeruginosa. the investigations were performed after the suspension method wi ... | 1979 | 120995 |
| some structure-activity relationships of iodophorous iodine complex compounds. part ii. biological. | the iodophors described in the part i [5] were subjected to studies in order to determine their antibacterial activity against staphylococcus aureus 209p, pseudomonas aeruginosa and escherichia coli. general effectiveness was evaluated and useful concentration was determined using the fda (food and drug administration) method and a test with mechanical carriers. the obtained results were compared with respective values for a commercial product--iosan (ciba--geigy); we found that properties of th ... | 1979 | 121159 |
| [preliminary results of an atiepizootic field test using edta-na extract vaccine from escherichia coli strains pathogenic to swine in swine production industrial units]. | an anti-epizootic field test was applied to industrialised pig farms in the region of wrocław, poland, to test the effectiveness of a pentavalent edta (calcium disodium edetate)--sodium vaccine extracted from escherichia coli strains with pathogenicity to swine. the vaccine had been received from a centre in berlin-buch, gdr. the vaccine failed to provide any protection, when orally applied to nursed piglets. however, both morbidity and mortality were reduced and, thus, an anti-epizootic effect ... | 1979 | 121226 |
| [action and teleaction of specific ligands on dna: a quantitative study with azbel's model and an application to the regulatory mechanism of the lac operon]. | assuming that the action of specific ligands is transferred to dna via the bases in close contact with the ligand, which are stabilized (or destablized) in this process, the local and more distant action of the ligand on dna can be evaluated quantitatively with the aid of azbel's model. an application to the system regulating the e. coli lac operon is presented. | 1979 | 121265 |
| disinfection of sewage by ultraviolet irradiation. | disinfection of sewage from an activated sludge process, and of sewage from an activated sludge process followed by chemical precipitation, has given very high killing rates for the indicator organisms examined. for coliforms, escherichia coli and faecal streptococci, a killing rate of more than 999.99% was usually obtained, and the residual number of microorganisms in the irradiated sewage was very low. the killing rate increased with the irradiation dosage, depending on the intensity of the ir ... | 1979 | 121372 |
| beta-galactosidase from osmotic remedial lactose utilization mutants of e. coli. | | 1979 | 121698 |
| [the antibacterial efficacy of cefaclor in routine testing of clinical material from two berlin hospitals (author's transl)]. | the agar diffusion method was used to test the antibacterial efficacy of cefaclor against bacterial strains isolated routinely from patients in two hospitals in berlin. a comparison was made with the efficacy of oxacillin, azlocillin, amikacin, gentamicin, ampicillin, co-trimoxazole, tetracycline, penicillin, cefazolin, nalidixic acid and nitrofurantoin. a total of 1235 strains of staphylococcus aureus, enterococci, escherichia coli, klebsiella, enterobacter, proteus species, citrobacter and pse ... | 1979 | 121730 |
| escherichia coli lac operator mrna affects translation initiation of beta-galactosidase mrna. | | 1979 | 121761 |
| [frequency and antibiotic resistance of bacteria isolated from urine cultures]. | the aa report the data pertinent to the urine culture performed during a year in the sanitary and prophylactic laboratory of the district of l'aquila. in urine samples with number of bacteria > 10(5)/ml have been found e. coli (49%), proteus mirabilis (32%), pseudomonas aeruginosa (12%), staphylococcus aureus (5%), proteus rettgeri (1%), enterococco (1%). the data are also reported concerning germ resistance to several antibiotics. | 1979 | 121968 |
| [researches on the production of inhibitory substances by strains of "n. meningitidis" (author's transl)]. | the possibility to produce some inhibitory substances has been researched in 85 strains of n. meningitidis belonging to different serogroups. by the double layer agar method, 9 of these strains have inhibited the growth of one or more indicator strains. we had the best results at 37 degrees c and 30 degrees c in tests made incubating 3 producer strains in different experiment conditions; the "brain heart infusion agar" and the "heart infusion agar" were the best and fittest culture media, used f ... | 1979 | 122053 |
| chemotaxis by lipids isolated from bacteroides fragilis. | living, heat or formalin killed bacteroides fragilis and a crude preparation of their cell walls were examined by the boyden technique for chemotactic activity upon guinea pig peritoneal exudate cells. their relative chemotactic activity ranged from 3.0 to 5.2 compared to an average value of 6.4 for the positive control, an endotoxic culture filtrate of escherichia coli. a culture filtrate of b. fragilis and an index of 3.7. miocrogram quantities of cytoplasmic preparations obtained by ammonium ... | 1979 | 122317 |
| enzyme immunoassay of human chorionic gonadotropin employing beta-galactosidase as label. | an enzyme-linked immunoassay was applied to the determination of hcg, a glycoprotein hormone usually assayed by ria. for this purpose, an enzyme hormone conjugate was prepared by reacting hcg with beta-d-galactosidase (beta-gal.) of e. coli in the presence of n-(m-maleimidobenzoyloxy) succinimide (mbs) as coupling reagent. the conjugate, after purification by affinity and gel chromatographies, was shown to exhibit sufficient enzyme activity and immunoactivity. the immunoassay of hcg was performe ... | 1978 | 122424 |
| functional capacities and the adenylate energy charge in escherichia coli under conditions of nutritional stress. | functional capacities in escherichia coli cells starved for glucose were examined by comparing protein synthesis, utilization of new substrates, and maintenance of viability with the adenylate energy charge of the culture. when growth ceased because of glucose exhaustion in an e. coli culture, the energy charge dropped from 0.90 to about 0.80. during this time, the viable-cell count and the capacity for protein synthesis and for induction of new enzymes were maintained only if other substrates w ... | 1977 | 122511 |
| piperacillin, a new penicillin active against many bacteria resistant to other penicillins. | the in vitro activity of piperacillin, a new semisynthetic piperazine penicillin derivative, was evaluated against 626 clinical isolates and compared with the activity of other beta-lactam antibiotics. at a concentration of 0.1 microgram/ml, piperacillin inhibited all streptococci except enterococci. non-beta-lactamase-producing staphylococci were inhibited by 1.6 microgram or less per ml. both beta-lactamase- and non-beta-lactamase-producing haemophilus were inhibited by 0.1 microgram/ml. piper ... | 1978 | 122519 |
| in vitro study of clavulanic acid in combination with penicillin, amoxycillin, and carbenicillin. | the activity of clavulanic acid alone and in combination with penicillin, amoxycillin, and carbenicillin was studied. marked reductions in the minimum inhibitory concentrations (mics) for a wide spectrum of beta-lactamase-producing clinical isolates were found. of particular interest were the decreased mics of penicillin for bacteroides fragilis and beta-lactamase-producing strains of neisseria gonorrhoea in the presence of the clavulanic acid. beta-lactamase-producing strains of escherichia col ... | 1978 | 122520 |
| totally synthetic medium for susceptibility testing. | the results of disk diffusion and plate dilution susceptibility testing of staphylococcus aureus, escherichia coli, pseudomonas aeruginosa, and proteus mirabilis on media gelled with agar-agar or with a synthetic hydrogel were compared. synthetic hydrogel can be combined with a totally defined synthetic amino acid medium to yield a reproducible, totally defined, synthetic solid medium without the antagonistic or booster effects of some components of agar. such a medium could be used as a referen ... | 1978 | 122521 |
| susceptibility of cephalothin-resistant gram-negative bacilli to piperacillin, cefuroxime, and other selected antibiotics. | the in vitro antibacterial activity of piperacillin and cefuroxime against 180 isolates of cephalothin-resistant enterobacteriaceae and of piperacillin against 46 isolates of pseudomonas aeruginosa was determined. amikacin, gentamicin, carbenicillin, cefoxitin, and cefamandole were included for comparison. the activities of piperacillin and carbenicillin against enterobacteriaceae were comparable. piperacillin was appreciably more active against pseudomonas than carbenicillin and was equivalent ... | 1978 | 122524 |
| regulation of the amount and of the activity of phosphofructokinases and pyruvate kinases in escherichia coli. | two isozymes of fructose-6-phosphate kinase and two isozymes of pyruvate kinase have been detected in escherichia coli under a wide variety of growth conditions. their kinetic behavior has been characteriized with respect to different effectors and substrates. the conclusions reached on one hand by malcovati and kornberg (biochim. biophys. acta (1969) 178, 420-423), on the other hand by fraenkel, kotlarz and buc (j. biol. chem. (1973) 248, 4865-4866) have been found to be true in aerobiosis as w ... | 1975 | 122902 |
| characterization of a bacteriophage t4 mutant lacking dna-dependent atpase. | a dna-dependent atpase has previously been purified from bacteriophage t4-infected escherichia coli. a mutant phage strain lacking this enzyme has been isolated and characterized. although the mutant strain produced no detectable dna-dependent atpase, growth properties were not affected. burst sizes were similar for the mutant phage and t4d in pola1, recb, recc, uvra, uvrb, uvrc, and various dna-negative e. coli. uv sensitivity and genetic recombination were normal in a variety of e. coli hosts. ... | 1975 | 123009 |
| transfection of escherichia coli spheroplasts. v. activity of recbc nuclease in rec+ and rec minus spheroplasts measured with different forms of bacteriophage dna. | the in vivo activity of the recbc nuclease was assayed by transfection of isogenic rec+ and rec minus spheroplasts with bacteriophage dna of various origin and structure. the results indicate that the recbc nuclease can limit transfection at several stages during the production of an infective center; such limitations depend primarily on whether the dna is in, or assumes, a nuclease-sensitive structure. the first stage of limitation can occur when a nuclease-sensitive transfecting molecule enter ... | 1975 | 123277 |
| escherichia coli phosphofructokinase: inhibition by 8-anilino-1-naphthalenesulfonate. | | 1975 | 123429 |
| energy requirements for biosynthesis of dna in escherichia coli. role of membrane-bound energy-transducing atpase (coupling factor). | a mutant of escherichia coli missing energy-transducing atpase and known to be defective in a variety of membrane functions from earlier studies (yamamoto, t. h., mével-ninio, m. and valentine, r. c. (1973) biochim. biophys. acta 314, 267-275; thipayathasana, p. and valentine, r. c. (1974) biochim. biophys. acta 347, 464-468; mével-ninio, m. and yamamoto, t. (1974) biochim. biophys. acta 357, 63-66) has been found to be blocked for anaerobic dna synthesis. the rate of anaerobic dna synthesis in ... | 1975 | 123769 |
| the maintenance of the energized membrane state and its relation to active transport in escherichia coli. | 1. an atpase mutant of escherichia coli and two partial revertants of that mutant were examined for the ability to generate a high energy membrane state with d-lactate or atp, as measured by the quenching of the fluorescent dye quinacrine. 2. all three strains showed reductions in the aerobically-driven quenching of fluorescence compared to the wild type, but the reduction could be reversed by the addition of eithern,n'-dicyclohexylcarbodiimide or the crude soluble atpase of the wild type. 3. th ... | 1975 | 123782 |
| atp-sensitive and atp-insensitive phosphofructokinase in escherichia coli k-12. | the purification and kinetic characteristics of two phosphofructokinases are described. aerobic cultures of escherichia coli exhibit two types of phosphofructokinase. both types are dimers of mol. wt 150,000 (subunit mol. wt 73,000), whereas the anaerobic culture of e. coli revealed only one type, which is a tetramer of mol. wt 350,000 (subunit mol. wt 90,000). type 1 of the aerobic enzyme, representing approximately 70% of the total enzyme activity, is atp-insensitive, whereas type ii and the a ... | 1975 | 123852 |
| subunit composition, function, and spatial arrangement in the ca2+-and mg2+-activated adenosine triphosphatases of escherichia coli and salmonella typhimurium. | | 1975 | 124154 |
| transport of alpha-methyl glucoside in mutants of escherichia coli k12 deficient in ca2+, mg2+-activated adenosine triphosphatase. | | 1975 | 124171 |
| restoration of active calcium transport in vesicles of an mg2+-atpase mutant of escherichia coli by wild-type mg2+-atpase. | | 1975 | 124173 |
| [influence of a colicinogenic strain, given perorally, on the occurence of various plasmids of e. coli in piglets fed by flavomycin (author's transl)]. | | 1975 | 124212 |
| lipophilic chelator inhibition of escherichia coli membrane-bound atpase activity and prevention of inhibition by uncouplers. | | 1975 | 124263 |
| elevation of a serum component in periodontal disease capable of modulating chemotactic infiltration. | serum from dental patients was examined for its capacity to affect migration of polymorphonuclear leukocytes toward a complement-independent chemotactic factor, bacterial filtrate of escherichia coli, (bf). seven subjects with advanced periodontitis, documented with clinical measurements of pocket depth, loss of attachment, indices for gingival inflammation and oral hygiene, were paired with normal subjects of similar age and sex. this study shows that patients whose only apparent clinical sym ... | 1975 | 124338 |
| potentiation of the toxicity of mithramycin by bacterial lipopolysaccharide. | the lethality for balb/c mice of 1,3-bis(2-chloroethyl)-1-nitrosourea, cytosine arabinoside, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, hydroxyurea, mithramycin, a polymyxin-like antibiotic (sq 21,286), polyadenylic polyuridylic acid, procarbazine, 5-[3,3-bis(2-chloroethyl)-1-triazeno]-imidazole-4-carboxamide (tic-mustard) or uracil arabinoside administered in combination with escherichia coli lipopolysaccharide (lps) was measured. simultaneously administered mithramycin and lps or tic-mustar ... | 1975 | 124549 |
| membrane reconstitution in chl-r mutants of escherichia coli k 12. vii. purification of the soluble atpase of supernatant extracts and kinetics of incorporation into reconstituted particles. | membrane-bound atpase (ec 3.6.1.3) of escherichia coli k 12 is released in a soluble form by the mechanical treatments applied to the cells in order to break them. the purification of the soluble enzyme is described. the purified protein gives a single band in 7.5% polyacrylamide gel electrophoresis. the molecular weight is estimated to be 350 000. the enzyme is cold-labile, mg-2+ dependent, insensitive to inhibition by n, n'-dicyclohexylcarbodiimide and specific for atp and adp. membranes deple ... | 1975 | 124590 |
| genetics of resistance to colicins in escherichia coli k-12: cross-resistance among colicins of group b. | this paper describes the isolation of mutants resistant to colicins of group b (i.e., colicins b, d, g, h, ia, ib, m, q, s1, and v). the 145 mutants studied in detail can be divided into nine phentopyic classes, based on their colicin-resistance patterns. they include the previously isolated tona, tonb exbb and cir mutants. each of the different phenotypic classes of mutants has been partially characterized, and some approximately mapped. sodium dodecyl sulfate-polyacrylamide gel electrophoresis ... | 1975 | 124727 |
| structural and functional studies of ribonucleoprotein fragments isolated from escherichia coli 50 s ribosomal subunits. | | 1975 | 124783 |
| suppression of spectinomycin resistance in a mutant of escherichia coli k-12. | a mutant of escherichia coli has been isolated which exhibits partial suppression of spectinomycin resistance. the site of mutation is in the streptomycin (stra) region and is closely linked to the spca gene. however, this gene, which we propose to call mod, is phenotypically distinguishable from both the neomycin-kanamycin (nek) and the ribosomal ambiguity gene (ram). the relative gene order is mod spca stra. in a cell-free protein synthesizing system, altered ribosomes appear to be responsible ... | 1975 | 125262 |
| pfkb and pfkc loci of escherichia coli. | mutants lacking escherichia coli phosphofructokinase (pfka, 78 min) are suppressed by the unlinked pfkb1 mutation, which restores some enzyme activity (morrissey and fraenkel, 1972). we here describe a secondary mutation at pfkb, "pfkb-," which abolishes the suppression as well as the low residual activity of unsuppressed pfka mutants. pfkb is at about 33 min. with the gene order grod-pps-phes-pfkb. a positive selection was found that yielded both the pfkb-mutations and a new similar mutation, p ... | 1975 | 125264 |
| pfka locus of escherichia coli. | pfka was know, on the basis of three mutants, as the likely locus of phosphofructokinase in escherichia coli, and the unlinked pfkb1 mutation suppressed these mutations by restoring some enzyme activity (morrissey and fraenkel, 1972). we now report a new search for the complete inactivation of pfka (e.g., by deletion or amber mutation), done to assess whether the pfkb1 suppression is by an independent enzyme, phosphofructokinase activity 2 (fraenkel, kotlarz, and buc, 1973). ten new phosphofruct ... | 1975 | 125265 |
| cytoplasmic membrane vesicles of escherichia coli. a simple method for preparing the cytoplasmic and outer membranes. | a simple preparative method is described for isolation of the cytoplasmic and outer membranes from e. coli. the characteristics of both membrane fractions were studied chemically, biologically, and morphologically. spheroplasts of e. coli k-12 strain w3092, prepared by treating cells with edta-lysozyme [ec 3.2.1.17], were disrupted in a french press. the crude membrane fraction was washed with 3 mm edta-10% (w/v) sucrose, ph 7.2, and the cytoplasmic membranes and outer membranes were separated b ... | 1975 | 125274 |
| the cleavage of transfer rna by a single strang specific endonuclease from neurospora crassa. | endonuclease from neurospora crassa (ncnase), an enzyme with specificity for polynucleotides lacking an ordered structure, was shown to cleave su+3 trnatyr from e. coli preferentially in the anticodon region. the enzyme cleaved unfractionated trna primarily to 30 - 50 nucleotide size fragments, implying that most or all trna species are also cleaved in the anticodon region. the 3' terminal sequence c-a was cleaved as well. the results are discussed with respect to the three dimensional structure ... | 1975 | 125412 |
| metabolite transport in mutants of escherichia coli k12 defective in electron transport and coupled phosphorylation. | 1. the uptakes of pi and serine by whole cells of mutant strains of escherichia coli k12, grown under both aerobic and anaerobic conditions, were studied. 2. uptake by aerobic cells was low in a ubiquinone-less mutant but normal in two mutant strains unable to couple phosphorylation to electron transport. 3. one of these uncoupled strains, carrying the unc-405 allele, does not form a membrane-bound mg2+-stimulated adenosine triphosphatase aggregate, and it is concluded that the mg2+-stimulated a ... | 1975 | 125586 |
| energy coupling for methionine transport in escherichia coli. | the source of metabolic energy for the accumulation of methionine in cells of escherichia coli was shown to differ from that for proline uptake. in contrast to proline uptake, methionine accumulation was sensitive to arsenate, and relatively resistant to azide or dinitrophenol. adenosine triphosphatase mutant strains also differentiated between the two systems, consistent with the conclusion that, although proline uptake is driven directly by the energized membrane state, methionine uptake is no ... | 1975 | 125747 |
| differentiation between mutants of escherichia coli k defective in oxidative phosphorylation. | hybrid membrane particles from two mutants of escherichia coli k12, bv4 and k11, defective in oxidative phosphorylation, have been prepared, in which atp-driven membrane energization is restored. a soluble factor of mutant k11 was found to have properties similar to parental crude coupling factor, atpase (ec 3.6.1.3). membrane particles of this mutant could not be reconstituted by parental coupling factor. either parental coupling factor, or the soluble factor of mutant k11 could reconstitute bo ... | 1975 | 126079 |
| mu-induced polarity in the escherichia coli k-12 ent gene cluster: evidence for a gene (entg) involved in the biosynthesis of enterochelin. | a strain of escherichia coli k-12 has been isolated that carries a mu bacteriophage-induced mutation in the ent gene cluster. nutritional tests together with examination of the compounds accumulated by the mutant strain indicated that the mutant was blocked both in the synthesis of 2,3-dihydroxy-benzoate and its subsequent conversion into enterochelin. enzymic complementation assays of the mutant with several mutants each affected in one of the ent genes showed that the mu-induced mutant was ent ... | 1975 | 126224 |
| the gamma protein specified by bacteriophage gamma. structure and inhibitory activity for the recbc enzyme of escherichia coli. | the protein encoded by the gam gene of bacteriophage lambda ("gamma protein") is a specific inhibitor of the recbc enzyme of escherichia coli. the lambda protein has been purified approximately 2,000-fold, and its structure and inhibitory activity have been characterized. it appears to be composed of two identical subunits of 16,500 daltons, inhibits all of the catalytic activities of the recbc enzyme with apparently equal efficiency, but has no effect upon any other e. coli or lambda-dnase test ... | 1975 | 126236 |
| late steps in the assembly of 30 s ribosomal proteins in vivo in a spectinomycin-resistant mutant of escherichia coli. | | 1975 | 126327 |
| endotoxin-like properties of the peptidoglycan. | peptidoglycan is responsible for the endotoxin-like properties of the streptococcus cell wall. the pyrogenic response of rabbit to group a streptococcus peptidoglycan prepared by hot formamide or tca is dose-dependent and is increased if the material is ultrasonically solubilized. the pyrogenicity can be eliminated by the antiserum to the peptidoglycan or by the degradation of the material by lysozyme. peptidoglycans prepared from cell walls of group b and l streptococci, staphylococcus aureus, ... | 1975 | 126556 |
| inhibition of excision repair without influence upon uv-sensitivity and uv-mutability in escherichia coli b/r hcr+. | pre-irradiation starvation of exponentially growing escherichia coli b/r hcr+ thy-try- strain for thymine and tryptophan causes inhibition of pyrimidine dimer excision from ultraviolet damaged cells dna. this inhibition of excision repair has not resulted in increasing ultraviolet sensitivity nor in increasing frequency of ultraviolet induced tryptophan revertants. the possible mechanisms of the non-excision repair in the prestarved cells, which is at least as accurate and effective as the whole ... | 1975 | 126583 |
| activation and inhibition of the mg-ca-atpase from e. coli by mg2+ and ca2+. | mgatp of caatp is the substrate of the mg-ca-atpase. at low mg2+- or ca2+-concentrations the atpase is activated by mg2+ or ca2+, the activator being essential for activity. at higher mg2+- or ca2+-concentrations the mg-ca-atpase is inhibited competitively. thus the real km is smaller than reported in the literature. h+ competes with mg2+ or ca2+ for the metal binding sites. | 1975 | 126584 |
| over-production of porphyrins and heme in heterotrophic bacteria. | in escherichia coli, pseudomonas aeruginosa, and achromobacter metalcaligenes gamma-aminolevulinic acid synthase and gamma-aminolevulinic acid dehydratase appear to be the rate limiting enzymes of porphyrin and heme biosynthesis. bypassing of these enzymes by addition of gamma-aminolevulinic acid or porphobilinogen results in overproduction of tetrapyrroles. | 1975 | 126586 |
| sensitivity of escherichia coli to viral nucleic acid, x. ba2+-induced competence for transfecting dna. | effect of alkaline earth metal ions on induction of the competence for dna transfection was investigated. unlike spheroplasts, the bulk of the bacteria treated with these ions retains colony-forming ability. the order of effectiveness for transfection of phia replicative-form dna has been found to be ba2+ greater than ca2+ greater than sr2+ greater than mg2+. the competence of ba2+-treated cells is 3 to 5 times higher that that of ca2+-treated bacteria and about 40 times higher than that of lyso ... | 1975 | 126594 |
| [second isolation of a enteropathogenous escherichia coli o 144 serotype in czechoslovakia (author's transl)]. | | 1975 | 126816 |
| poly(a) synthesis in t2l phage-infected escherichia coli. a combination of polynucleotide phosphorylase and atpase. | in crude extracts of t2l phage-infected escherichia coli cells an enzyme activity was found that produced poly(a) from atp as substrate. purification of the extract led to the isolation of two enzymes, a polynucleotide phosphorylase and an atpase. the polynucleotide phosphorylase possessed the same properties as the well-known enzyme from uninfected cells and its molecular weight was about 265 000. the atpase was purified to over 90% purity; its molecular weight was estimated to be about 165 000 ... | 1975 | 126862 |
| proceedings: influence of anions, mg2 and mgatp on the activity of e. coli adenosinetriphosphatase. | | 1975 | 126940 |
| relationship between the tonb locus and iron transport in escherichia coli. | when a strain (arcb-) of escherichia coli, unable to synthesize the iron transport compound enterochelin, was transduced to tonb-, it became resistant to phage phi80 and simultaneously lost the growth response to enterochelin and the ability to transport its iron complex. however, enterochelin precursors (shikimate and 2,3-dihydroxybenzoate) still supported growth, via the synthesis of enterochelin. dihydroxybenzoate was a better growth factor at a low concentration than it was at higher levels. ... | 1975 | 126991 |
| identification of the dicyclohexylcarbodiimide-reactive protein component of the adenosine 5'-triphosphate energy-transducing system of escherichia coli. | membranes of escherichia coli contain an adenosine 5'-triphosphate (atp) energy-transducing system that is inhibited by treatment with dicyclohexylcarbodiimide (dccd). the carbodiimide-reactive protein component of this system has been identified after treatment with [14c]dccd. this protein has an apparent molecular weight of 9,000 as judged from acrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and is extracted from the membrane with chloroform-methanol (2:1). these prope ... | 1975 | 126994 |
| partial purification and properties of a bacteriophage t7 inhibitor of the host exonuclease v activity. | infection of escherichia coli with bacteriophage t7 results in an inhibition of the host exonuclease v (recb, c dnase) activity. this inhibition is not observed when cells are infected in the presence of chloramphenicol or with a gene 1 mutant. the protein responsible for the inhibition of exonuclease v has been partially purified from t7-infected cells. the protein which does not possess nuclease or atpase activity can inhibit all nucleolytic activities associated with exonuclease v. the protei ... | 1975 | 127051 |
| partial purification of active delta and epsilon subunits of the membrane atpase from escherichia coli. | we have partially purified active delta and epsilon subunits of the e. coli membrane-bound mg2+-atpase (ecf1). treating purified ecf1 with 50% pyridine precipitates the major subunits (alpha, beta, and gamma) of the enzyme, but the two minor subunits (delta and epsilon), which are present in relatively small amounts, remain in solution. the delta and epsilon subunits were then resolved from one another by anion exchange chromatography. the partially purified epsilon strongly inhibits the hydroly ... | 1975 | 127087 |
| crosslinking studies on the ca2+, mg2+-activated atpase of escherichia coli. | crosslinking of membrane proteins of escherichia coli with dithiobis (succinimidyl propionate) (dsp) resulted in loss of several enzyme activities including the ca2+, mg2+-activated atpase. this enzyme was crosslinked by dsp to the membrane and was not released by dialysis at low ionic strength in the absence of dithiothreitol which could cleave the crosslinking group. dsp inactivated both phosphohydrolase and coupling activities of the solubilized atpase. loss of hydrolytic activity could be co ... | 1975 | 127090 |
| effects of some antibiotics on the stringent control of rna synthesis in escherichia coli. | effects of neomycin, spectinomycin, tetracycline and chloramphenicol on the stringent control rna synthesis and on ppgpp synthesis in the rel+-cells of escherichia coli having a temperature-sensitive valyl-trna synthetase were examined. without antibiotics, ppgpp began to accumulate and both rna and protein syntheses were inhibited by transferring the exponentially growing cells from 30 degrees c (permissive temp.) to 40 degrees c (non-permissive temp.). tetracycline or chloramphenicol, when add ... | 1975 | 127113 |
| mobilization of plasmid-borne drug resistance determinants for transfer from pseudomonas aeruginosa to escherichia coli. | rsu2, a plasmid transmissible between strains of p. aeruginosa but not to escherichia coli can be mobilized by r751. conjugatants receive a single plasmid composed of dna from both r751 and rsu2 which has the compatibility properties of a member of group p (like r751). study of this fusion plasmid suggests that the failure of rsu2 to transfer into enterobacteria is due to an inability to replicate in these bacteria. the fusion plasmid replicates using the genes of r751. | 1975 | 127114 |
| arrangement of sequences in the inverted terminal repetition of adenovirus 18 dna. | in contrast to the single-stranded circular molecules produced with denatured dna from other adenoviruses, there was associated with nearly all circular molecules of adenovirus type 18 a visible, duplex projection. these projections had a mean contour length of 0.31 +/- 0.12 mum, equivalent to approximately 3% of genome length. individual projections ranged in size from 0.1 to 2 mum. alkaline sucrose gradient purification of single-stranded molecules did not affect formation of these projections ... | 1975 | 127173 |
| association of phix174 dna-dependent atpase activity with an escherichia coli protein, replication factor y, required for in vitro synthesis of phix174 dna. | phix174 dna-dependent dna synthesis is catalyzed in vitro by the combination of at least 11 purified protein fractions: dnab, dnac(d), and dnag gene products, dna polymerase iii, dna elongation factors i and ii, dna binding protein, and replication factors w, x, y, and z. the reaction requires atp, 4 dntps, and mg+2 and is specific for phix174 (or phixahb) dna. purified replication factor y contains phix174 (or phixahb) dna-dependent atpase (or datpase) activity. the atpase activity is poorly st ... | 1975 | 127175 |
| [studies on the in vitro formation of antibodies. iii. induction of primary and secondary immune response in vitro]. | peritoneal cells from normal, unimmunized mice (female nmri, 28-32 gr) produced in vitro primary and secondary immune response after induction with the bacteriophage t2 6 hours or 7 day resp. after establishing the cultures. we confirmed the induction of a primary and secondary immunological response in vitro in the very same culture by the following data: 1. in vivo the donor animals were not in contact with the antigen used. we found neither the phage nor its host e. coli b in the gut of 97 mi ... | 1975 | 127451 |
| kinetics of the ion-sensitive mg, ca-adenosinetriphosphatase (atpase) from escherichia coli. | | 1975 | 127549 |
| the degradation of duplex dna by the recbc dnase of escherichia coli. | | 1975 | 127577 |
| purification and characterization of a dicyclohexylcarbodiimide-sensitive adenosine triphosphatase complex from membranes of escherichia coli. | | 1975 | 127583 |
| trna gene clusters in escherichia coli dna. | | 1975 | 127650 |
| physiological suppression of a transport defect in escherichia coli mutants deficient in ca2+, mg2+-stimulated adenosine triphosphatase. | transport properties of membrane vesicles isolated from two adenosine triphosphatase-deficient mutants of escherichia coli, nr70 and dl54, were compared with those of vesicles prepared from the corresponding parental strains. as reported previously (rosen, 1973; altendorf et al., 1974), vesicles prepared from these mutants grown under aerobic conditions exhibited defective amino acid transport, and activity was restored after treatment with dicyclohexylcarbodiimide. in sharp contrast, however, v ... | 1975 | 127784 |
| anaerobic energy-yielding reaction associated with transhydrogenation from glycerol 3-phosphate to fumarate by an escherichia coli system. | a particulate subcellular fraction from escherichia coli k-12 induced in anaerobic sn-glycerol 3-phosphate (g3p) dehydrogenase and fumarate reductase can catalyze under anaerobic conditions the transfer of hydrogens from g3p to fumarate, with attendant generation of high-energy phosphate. the phsophorylation process is more sensitive than the transhydrogenation process to inhibition by the detergent triton x-100. the same is true with respect to sensitivity to sodium azide, carbonyl cyanide m-ch ... | 1975 | 127785 |
| electron transport chain from glycerol 3-phosphate to nitrate in escherichia coli. | it is known that in escherichia coli two dehydrogenases of the flavoprotein kind can participate in the transfer of hydrogens from sn-glycerol 3-phosphate (g3p) to nitrate and that possession of either enzyme is sufficient to permit anaerobic growth on glycerol as carbon source and nitrate as hydrogen acceptor. results from this study show that under such a growth condition a protein with light-absorption characteristics of cytochrome b1 is induced. if g3p, nitrate, and adenosine diphosphate are ... | 1975 | 127786 |
| transport of sugars and amino acids in bacteria. xiv. preferential inhibition of oxidase activities and active transport reactions for amino acids by azidebenzenes. | 4-methylazidebenzene and various azidebenzene derivatives were prepared, and the effects of these compounds on oxidase activities and active transport reactions for amino acids in escherichia coli cells were studied. azidebenzenes inhibited succinate oxidation by intact cells preferentially to glycerol oxidation. however, the azidebenzenes could not inhibit succinate oxidation which was not coupled to phosphorylation. the compounds inhibited succinate driven proline uptake much more strongly th ... | 1975 | 127788 |
| energy transduction in escherichia coli. the role of the mg2+atpase. | inverted membrane vesicles from strain 7, a wild type escherichia coli k12 strain, actively transport calcium with energy supplied either by respiration or by atp. these vesicles also have energy-linked quenching of quinacrine fluorescence. membranes of strain 7, depleted of mg2+atpase by edta treatment, lack both activities. membrane vesicles from strain nr70, a mutant lacking the mg2+atpase, show neither calcium transport nor energy-linked fluorescence quenching. neither edta treatment nor gen ... | 1975 | 127791 |
| energy transduction in escherichia coli. genetic alteration of a membrane polypeptide of the (ca2+,mg2+)-atpase. | recent genetic analyses of the membrane components involved in energy transduction in escherichia coli have concentrated on the (ca2+, mg2+)-atpase complex (ec 3.6.1.3). many mutants have been described with altered biochemical properties and defects in energy-requiring processes such as oxidative phosphorylation, transhydrogenase activity, and active transport of several solutes. this report describes the isolation of a mutant strain of e. coli that is defective in several energy-requiring proc ... | 1975 | 127796 |
| membrane bound and soluble adenosine triphosphatase of escherichia coli k 12. kinetic properties of the basal and trypsin-stimulated activities. | basal and trypsin-stimulated adenosine triphosphatase activities of escherichia coli k 12 have been characterized at ph 7.5 in the membrane-bound state and in a soluble form of the enzyme. the saturation curve for mg2+/atp = 1/2 was hyperbolic with the membrane-bound enzyme and sigmoidal with the soluble enzyme. trypsin did not modify the shape of the curves. the kinetic parameters were for the membrane-bound atpase: apparent km = 2.5 mm, vmax (minus trypsin) = 1.6 mumol-min-1-mg protein-1, vmax ... | 1975 | 127930 |
| viability of escherichia coli treated with colicin k. | conditions permitting survival (colony formation) of e. coli after treatment with colicin k have been found. survival required k+ and mg2+ at concentrations high enough to replace the intracellular ions lost from colicintreated cells. either glucose minimal medium or broth could support survival. survival was still observed after colicin-promoted efflux of rb+ and decline in atp levels had occurred, and after the period during which treatment with trypsin could rescue the cells on media containi ... | 1975 | 128002 |
| sucrose-dependent spectinomycin-resistant mutants of escherichia coli. | spectinomycin-resistant (spcr) mutants of escherichia coli were isolated from nutrient agar plates containing 20% sucrose and 100 mug of spectinomycin per ml. about one-third of the spcr mutants thus obtained were sucrose dependent (sucd) and were classified into two types: i, those unable to grow on sucrose-free medium in the presence of spectinomycin; and ii, those unable to grow on sucrose-free medium irrespective of the presence of spectinomycin. most of these mutants were hypersensitive to ... | 1976 | 128550 |
| nature of the energy requirement for the irreversible adsorption of bacteriophages t1 and phi80 to escherichia coli. | the nature of the energy requirement for irreversible adsorption of phages t1 and phi80 was studied by using various specific energy inhibitors and mutants lacking either the ca2+, mg2+-adenosine triphosphatase or the ability to produce cytochromes in the absence of added 5-aminolaevulinic acid. it was found that irreversible adsorption could be energized both through the electron transport chain and from adenosine 5'-triphosphate via the ca2+, mg2+-adenosine triphosphatase, indicating the invol ... | 1976 | 128553 |
| mutant of escherichia coli defective in response to colicin k and in active transport. | a mutant of escherichia coli has been isolated that grows poorly on succinate and exhibits a markedly reduced sensitivity to colicin k. this mutant is also deficient in the respiration-linked transport of proline and thiomethyl-beta-d-galactoside but appears normal for the adenosine triphosphate-dependent transport of glutamine and arginine. a temperature-conditional revertant of the mutant grows on succinate and is sensitive to colicin k at 27 c, but fails to grow on succinate and is insensitiv ... | 1976 | 128554 |
| coordinated alterations in ribosomes and cytoplasmic membrane in sucrose-dependent, spectinomycin-resistant mutants of escherichia coli. | alterations in cytoplasmic membrane and ribosomes from sucrose-dependent spectinomycin-resistant (sucd-spcr) mutants of escherichia coli, mutants that are resistant to spectinomycin in the presence of 20% sucrose but sensitive in the absence of sucrose, were studied. the protein composition of cytoplasmic membrane was analyzed by gel electrophoresis on polyacrylamide gel containing 8 m urea and 0.5% sodium dodecyl sulfate, which assured the reproducible separation of 28 protein bands. a major pr ... | 1976 | 128555 |
| purification and characterization of a dna-dependent atpase from escherichia coli. | a dna-dependent atpase has been isolated and purified from an escherichia coli cell-free extract. the atpase has the following characteristics: preferential dependence on single-stranded dna, specificity for atp hydrolysis, km value of 1.4 x 10-4 m for atp, and molecular weight of approximately 69,000. the atpase can be shown to bind to single stranded dna. the resemblance between this atpase and that isolated from vaccinia cores is discussed. | 1976 | 129472 |
| genetic position and amino acid replacements of several mutations in ribosomal protein s5 from escherichia coli. | the relative genetic position of the following four mutations of ribosomal protein s5 has been determined: spc-13, a mutation to spectinomycin resistance; stri n421 and strid1023, mutations suppressing dependence on streptomycin and sup0-1, a mutation suppressing partially the temperature-sensitive phenotype of an alanyl-trna synthetase mutation. the transduction experiments performed indicate that the spc-13 site is located in the s5 cistron proximal to the stra locus, that sup0-1 maps proximal ... | 1975 | 129673 |
| inducibility of lambda phage development in escherichia coli mutants thermosensitive for dna replication. | in a thermosensitive dnaz mutant lysogenic for lambda, induction of the prophage development was provoked at the restrictive temperature. in dnad strain, spontaneous release of lambda proceeded even at 43 degrees c, but distinct induction of the prophage development was not caused by a heat treatment. similarly, shift up of growth temperature did not lead to induction of lambda in lysogens carrying thermosensitive mutation in dnah function or dna polymerase i. in dnah mutant, multiplication of l ... | 1975 | 130012 |
| phospholipids and atpase activity of wild-type and atpase deficient and uncoupled mutants of e. coli. | the atpase activities and the amounts of individual phospholipids in e. coli wild types b163 and ml-308-225 as well as in the mutants an120, dl54 and etc-15 have been examined. the atpase activities and the amount of cardiolipin are higher in the stationary phase than in the log phase, whereas the amounts of phosphatidylglycerol and phosphatidylserine are lower in the stationary phase. the decreased atpase activity of the mutants is not due to an altered phospholipid composition. | 1975 | 130017 |
| membrane potential generation in mutants of escherichia coli with alterations in the membrane atpase complex. studies on intact cells. | | 1976 | 130254 |
| expression of the arga gene carried by a defective lambda bacteriophage of escherichia coli. | evidence is presented that the increase in specific activity of n-acetylglutamate synthase observed upon heat induction of escherichia coli (lambdadarga) is primarily due to a gene dosage effect. | 1976 | 130376 |
| hfr formation by i pilus-determining plasmids in escherichia coli k-12. | r483, an atypical, i pilus-determining plasmid, and also r144, a typical one, were shown to suppress the dnaa phenotype by integration into the escherichia coli chromosome. | 1976 | 130378 |
| postinfection control by bacteriophage t4 of escherichia coli recbc nuclease activity. | infection by bacteriophage t4 has previously been shown to cause a rapid inhibition of the host recbc dnase, an atp-dependent dnase that is required for genetic recombination in escherichia coli. we report here the partial purification of a protein ("t4 rec inhibitor") from extracts of t4-infected cells and some characteristics of the in vitro inhibition reaction with purified inhibitor and recbc nuclease. this inhibitory activity could not be purified from extracts of uninfected e. coli. both t ... | 1976 | 130501 |
| anaerobic transport of amino acids coupled to the glycerol-3-phosphate-fumarate oxidoreductase system in a cytochrome-deficient mutant of escherichia coli. | the uptake of proline and glutamine by cytochrome-deficient cells of escherichia coli sasx76 grown aerobically on glucose or anaerobically on pyruvate was stimulated by these two substrates. pyruvate could not stimulate transport in the glucose-grown cells. uptake of these amino acids energized by glucose was inhibited by inhibitors of the ca2+, mg2+-stimulated atpase such as dccd, pyrophosphate, and azide, and by the uncouplers cccp and 2,4-dinitrophenol. glycerol (or glycerol 3-phosphate) in t ... | 1976 | 130924 |
| siderophore protection against colicins m, b, v, and ia in escherichia coli. | a variety of natural and synthetic siderophores capable of supporting the growth of escherichia coli k-12 on iron-limited media also protect strain rw193+ (tona+ ent-) from the killing action of colicins b, v, and ia. protective activity falls into two categories. the first, characteristic of enterobactin protection against colicin b and ferrichrome protection against colicin m, has properties of a specific receptor competition between the siderophore and the colicin. thus, enterobactin specific ... | 1976 | 131121 |
| mechanisms of siderophore iron transport in enteric bacteria. | uptake of 55fe- and 3h-labeled siderophores and their chronic analogues have been studied in salmonella typhimurium lt-2 and escherichia coli k-12. in s. typhimurium lt-2, at least two different mechanisms for siderophore iron transport may be operative. uptake of 55fe- and 3h-labeled ferrichrome and kinetically inert lambda-cis-chromic [3h]deferriferrichrome by the s. typhimurium lt-2 enb7 mutant, which is defective in the production of its native siderophore, enterobactin, appears to occur by ... | 1976 | 131124 |