Showing papers on "Bacteria published in 1978"
01 Jun 1978
TL;DR: A rapid method for distinction between gram-negative and grampositive bacteria by means of a 3% solution of potassium hydroxide is tested, with one exception only, a Bacillus macerans strain, which was definately gram- negative on staining.
Abstract: A rapid method for distinction between gram-negative and grampositive bacteria by means of a 3% solution of potassium hydroxide is tested on 71 gram-positive and 55 gram-negative bacterial strains. The method proved reliable with one exception only, a Bacillus macerans strain. That strain was definately gram-negative on staining. Other Bacillus strains were proved gram-positive by the test, even those being gram-negative on staining.
887 citations
TL;DR: Glutathione and soluble thiol content were examined in a broad spectrum of bacteria and the glutathione content of Escherichia coli increased significantly during transition from exponential to stationary phase.
Abstract: Glutathione and soluble thiol content were examined in a broad spectrum of bacteria. Significant soluble thiol was present in all cases. The thiol compound was glutathione in most of the gram-negative bacteria but not in most of the gram-positive bacteria studied. Glutathione was absent in four anerobes and one microaerophile but was present in a blue-green bacterium. The glutathione content of Escherichia coli increased significantly during transition from exponential to stationary phase.
488 citations
01 Jun 1978
TL;DR: A correlation between aminopeptidase activity and distinct interpeptide bridge composition in the peptidoglycan of many strains was demonstrated and the influence of growth conditions on aminOPEptid enzyme activity of intact bacterial cells is shown.
Abstract: The aminopeptidase test was performed with representatives of gram-negative, gram-positive, and gram-variable bacteria. All gram-negative bacteria tested gave a positive test reaction with L-alanine-4-nitroanilide as test substrate. Representatives of the coryneform bacteria and some streptococci showed aminopeptidase activity after prolonged reaction times. A correlation between aminopeptidase activity and distinct interpeptide bridge composition in the peptidoglycan of many strains was demonstrated. The influence of growth conditions on aminopeptidase activity of intact bacterial cells is shown.
258 citations
TL;DR: A new antitumor antibiotic is produced in fermentation liquors of Streptomyces zelensis sp.n.
Abstract: A new antitumor antibiotic is produced in fermentation liquors of Streptomyces zelensis sp.n. The antibiotic is biologically active at extremely low concentrations. At 40 pg/ml, it inhibited 90% of the growth of L1210 cells in culture in tube dilution assays. The minimal inhibitory concentrations against Gram-positive bacteria is between 1 approximately 10 ng/ml, while these values for Gram-negative bacteria and fungi are mostly under 1 microgram/ml. A microbiological assay with Bacillus subtilis can detect concentrations of 1 approximately 2 ng/ml.
254 citations
TL;DR: A replica plating method for rapid quantitation of ice nucleation-active (INA) bacteria was developed and numbers of INA bacteria were large enough to suggest that plant surfaces may constitute a significant source of atmospheric ice nuclei.
Abstract: A replica plating method for rapid quantitation of ice nucleation-active (INA) bacteria was developed. Leaf washings of plant samples from California, Colorado, Florida, Louisiana, and Wisconsin were tested for the presence of INA bacteria. Of the 95 plant species sampled, 74 were found to harbor INA bacteria. Only the conifers were, as a group, unlikely to harbor INA bacteria. All of the INA bacteria isolated resembled either Pseudomonas syringae or Erwinia herbicola. Sufficient numbers of INA bacteria were present on the samples to account for the ice nuclei associated with leaves that are necessary for freezing injury to occur. Numbers of INA bacteria were large enough to suggest that plant surfaces may constitute a significant source of atmospheric ice nuclei.
252 citations
TL;DR: The ability of the H2 utilising sulphate reducing bacteria to inhibit Methanococcus competitively was shown in cultures containing both of these H1 utilising bacteria.
Abstract: A methanogenic bacterial consortium was obtained after inoculation of benzoate medium under N2/CO2 atmosphere with intertidal sediment. A hydrogen donating organotroph andMethanococcus mazei were isolated from this enrichment. H2-utilising sulphate reducing bacteria were isolated under H2/CO2 in the absence of organic electron donors. TheMethanococcus was able to produce methane in yeast extract medium under N2/CO2 if the H2 donating organism was present, and sulphate reduction occurred if the hydrogen utilising sulphate reducing bacteria were grown with the H2 donating organism. The ability of the H2 utilising sulphate reducing bacteria to inhibitMethanococcus competitively was shown in cultures containing both of these H2 utilising bacteria.
213 citations
TL;DR: Studies of medium and fermentation conditions indicated that the highest antibiotic titers, ca 900 u/ml, are obtained in a medium containing 1% (w/v) glucose, 2% cotton seed meal, 1% malt extract, and 0.4% yeast extract.
Abstract: A soil isolate of Actinoplanes that produces the chemically unrelated new antibiotics teichomycins A1 and A2 has been proposed as a new species named Actinoplanes teichomyceticus nov. sp. (ATCC 31121). Studies of medium and fermentation conditions indicated that the highest antibiotic titers, ca 900 u/ml, are obtained in a medium containing 1% (w/v) glucose, 1% cotton seed meal, 1% malt extract, and 0.4% yeast extract. Both teichomycin A1 and teichomycin A2 are highly active against gram-positive bacteria. Teichomycin A1 shows some activity against gram-negative bacteria. Both antibiotics cured mice experimentally infected with sensitive bacteria and showed low acute toxicity. Of the two antibiotics teichomycin A2 is the more active.
212 citations
TL;DR: The gram-negative bacteria tested can be divided into four major classes according to their responses to modifications in iron levels in the chick embryo model and these results correlate with the nature of the infections which they typically produce in man.
Abstract: The ability of potential pathogens to acquire iron in a host is an important determinant of both their virulence and the nature of the infection produced. Virulent gram-negative bacteria are capable of acquiring sufficient iron from the host because their virulence (for chick embryos) is unaffected by exogenous iron. Avirulent mutants which are apparently limited in their ability to acquire iron could be isolated from the virulent strains. The lethality of these mutants was significantly enhanced by exogenous iron. Reduction of the relatively high serum iron saturation of chick embryos (to levels more closely approximating those in man) by pretreatment with iron-binding proteins or endotoxin inhibits the lethality of some virulent bacteria. Those bacteria whose virulence was reduced include the Shigella, Vibrio cholerae and strains of Neisseria gonorrhoeae, all of which are nondisseminating pathogens in the normal human host. Pathogens which produce septicemic and disseminating infections such as Neisseria meningitidis, Haemophilus influenzae type B, Escherichia coli possessing K-1 antigen, Pseudomonas aeruginosa and Salmonella typhimurium and disseminating strains of N. gonorrhoeae were, in general, unaffected by reduced serum iron saturation. These disseminating bacteria appeared to produce greater quantities of compounds (siderophores) which stimulated microbial growth in low-iron media than did the nondisseminating pathogens. Thus, the gram-negative bacteria tested can be divided into four major classes according to their responses to modifications in iron levels in the chick embryo model and these results correlate with the nature of the infections which they typically produce in man.
193 citations
TL;DR: The data indicate that superoxide dismutase activity and oxygen reduction rates are important determinants related to the tolerance of anaerobic bacteria to oxygen.
Abstract: The effect of atmospheric oxygen on the viability of 13 strains of anaerobic bacteria, two strains of facultative bacteria, and one aerobic organism was examined. There were great variations in oxygen tolerance among the bacteria. All facultative bacteria survived more than 72 h of exposure to atmospheric oxygen. The survival time for anaerobes ranged from less than 45 min for Peptostreptococcus anaerobius to more than 72 h for two Clostridium perfringens strains. An effort was made to relate the degree of oxygen tolerance to the activities of superoxide dismutase, catalase, and peroxidases in cell-free extracts of the bacteria. All facultative bacteria and a number of anaerobic bacteria possessed superoxide dismutase. There was a correlation between superoxide dismutase activity and oxygen tolerance, but there were notable exceptions. Polyacrylamide gel electropherograms stained for superoxide dismutase indicated that many of the anaerobic bacteria contained at least two electrophoretically distinct enzymes with superoxide dismutase activity. All facultative bacteria contained peroxidase, whereas none of the anaerobic bacteria possessed measurable amounts of this enzyme. Catalase activity was variable among the bacteria and showed no relationship to oxygen tolerance. The ability of the bacteria to reduce oxygen was also examined and related to enzyme content and oxygen tolerance. In general, organisms that survived for relatively long periods of time in the presence of oxygen but demonstrated little superoxide dismutase activity reduced little oxygen. The effects of medium composition and conditions of growth were examined for their influence on the level of the three enzymes. Bacteria grown on the surface of an enriched blood agar medium generally had more enzyme activity than bacteria grown in a liquid medium. The data indicate that superoxide dismutase activity and oxygen reduction rates are important determinants related to the tolerance of anaerobic bacteria to oxygen.
147 citations
TL;DR: This work has shown that inhibition of growth by Organic Compounds and Regulation of enzyme activity and regulation of enzyme synthesis are driven by different mechanisms, and these mechanisms can be influenced by different underlying mechanisms.
Abstract: INTRODUCTION 434 OBLIGATE CHEMOLITHOTROPHS .... ..... ........ ........ 434 Inhibition of Growth by Organic Compounds 434 �. n oj Organic Compounds 437 AsstmllatlOn 437 Stimulation of growth 439 Dependence on CO] 441 Central Metabolic Pathways 441 Krebs cycle 441 Enzymes of pyruvate formation from sugars 442 Enzyme Regulation 443 Regulation of enzyme activity 443 Regulation of enzyme synthesis 444 Transport Mechanisms 444 Heterotrophic Growth 447 Thiobacillus ferroaxidans 449
TL;DR: By incubation of activated and digester sludge under different environmental conditions, it was shown that phototrophic bacteria can complete with other bacteria only under anaerobic conditions in the light.
Abstract: In all purification stages of a biological sewage treatment plant, phototrophic bacteria were detected by the method of viable cell counts. The predominant species identified belonged to the genus Rhodopseudomonas of purple nonsulfur bacteria. The number of phototrophic bacteria was highest in wastewater containing sludge. In activated sludge, an average of 10(5) viable cells/ml was found; the number depended upon concentration of sludge rather than on seasonal changes in light conditions in the course of a year. Bacteriochlorophyll a was extracted from activated sludge. Relative to the viable counts of phototrophic bacteria, the content of bacteriochlorophyll a was 5- to 10-fold higher than that of three representative pure cultures. By incubation of activated and digester sludge under different environmental conditions, it was shown that phototrophic bacteria can complete with other bacteria only under anaerobic conditions in the light.
TL;DR: Measurements of heterotrophic substrate uptake and turnover rates of water-soluble substances suggest that these parameters are closely related to the degree of eutrophication of a water body.
TL;DR: Adherence of Escherichia coli to D -mannose-like residues on epithelial cells may be an important step in bacterial infection, and this raises the possibility of using simple sugars, such as methyl α - D-mannoside, in the prevention of infection by certain gram-negative bacteria.
TL;DR: Cellular fatty acid composition of 50 strains of the genus Pseudomonas was determined by gas-liquid chromatography and similarity values calculated on the basis of fatty acids exhibited a clear correlation to the taxonomic groups of this genus.
Abstract: Cellular fatty acid composition of 50 strains of the genus Pseudomonas was determined by gas-liquid chromatography. Straight-chain saturated acid of C16:0 and straight-chain unsaturated acids of C16:1 and C18:1 with a double bond were commonly found in all the strains tested. The presence of hydroxy acids, cyclopropane acids, and branched-chain acids showed the characteristics for the groups and species in the genus Pseudomonas. Similarity values calculated on the basis of fatty acids exhibited a clear correlation to the taxonomic groups of this genus. Bacterial fatty acid composition was considered to be useful for the study of interrelation and for rapid identification of the bacteria. Taxonomic studies on bacteria have been mainly carried out on the basis of morphological, biochemical, and physiological characteristics. Recently, chemical constituents of bacterial cells have become of interest from the point of taxonomy, and DNA base composition, cell wall composition, and type of co-enzyme Q have been used for taxonomic criteria in some taxa. The progress of instrumental analyses has contributed to the development of chemotaxonomy, and the results involved have been useful not only for the bacterial classification, but also for rapid identification of the bacteria.
TL;DR: A hybrid gene was constructed between the β-lactamase gene of plasmid pBR322 and the cloned coding sequence for rat growth hormone and this gene is expressed in bacteria and growth hormone sequences are detectable by immunological methods.
Abstract: A hybrid gene was constructed between the beta-lactamase gene of plasmid pBR322 and the cloned coding sequence for rat growth hormone. This gene is expressed in bacteria and growth hormone sequences are detectable by immunological methods.
TL;DR: The characterisation of a mutant that has gained resistance to some β-lactams by a decrease in the affinity of such a target is reported.
Abstract: CLINICAL isolates of bacteria that have gained resistance to β-lactam antibiotics (penicillins, cephalosporins and related compounds) often arise by the acquisition of a plasmid that produces a β-lactamase1,2. An increase in β-lactamase activity has also been shown to cause resistance in some mutants isolated in the laboratory3. In other cases, β-lactamase activity is not the cause of resistance and, at least in Gram-negative bacteria, alteration of the cell envelope resulting in decreased penetration of the antibiotic to the targets responsible for lethality in the cytoplasmic membrane has been proposed3,4. For several groups of antibiotics resistance has been shown to occur by a decrease in the affinity of the target for lethality for the antibiotic5–9 but, although this mechanism has been suggested as a possible cause of resistance to β-lactam antibiotics, no examples have been reported. The lethality targets for β-lactam antibiotics in Escherichia coli have recently been identified and I report here the characterisation of a mutant that has gained resistance to some β-lactams by a decrease in the affinity of such a target.
TL;DR: Algal‐bacterial mutualism aids Anabaena in maintaining concurrent optimal N2 fixation and high photosynthetic rates in highly oxygenated surface waters.
Abstract: The functional aspects of specific associations between bluegreen algae and bacteria were investigated using both naturally occurring and cultured species of Anabaena. In take waters where bacteria were associated with Anabaena heterocysls, the bacteria exhibited a chemotactic response to a variety of amino acids and glucose. Earlier autoradiographic evidence that bacteria associated with heterocysts incorporate identical substrates indicates that associated bacteria probably benefit by utilizing algal excretion products. In return, the bacteria stimulate algal N2fixation. The most likely mechanism explaining such stimulation appeared to be bacterial oxygen removal in microzones (< 3 μm diam) bordering heterocysts during periods of high ambient oxygen concentrations. In the presence of bacteria, Anabaena rapidly overcame nitrogenase- inhibiting concentrations of oxygen. Axenic cullures had more extensive nitrogenase inhibition, and took longer to recover in response to oxygenation. Algal-bacterial mutualism aids Anabaena in maintaining concurrent optimal N2 fixation and high photosynthetic rates in highly oxygenated surface waters.
TL;DR: The interactions observed can be explained as a combination of competition and indirect parasitism, and preliminary characterization of the material excreted by the bacteria indicates that it s proteinaceous in nature.
Abstract: The marine diatom Thallasiosira pseudonanna (3H) and several bacteria associated with it were isolated from batch cultures at the University of Delaware mariculture facility. The interaction between the algae and each of the bacteria was investigated. One of the isolates, T827/2B (Pseudomonas sp.), was incapable of surviving in f/2 culture medium unless the algae were present. When the algae and T827/2B were grown together in the f/2 medium, the bacterial growth was stimulated and the algal growth was inhibited. Bacterial filtrate had a similar effect on the algae, indicating that the bacterial effect is an indirect one most likely resulting from the excretion of a harmful compound into the medium. Preliminary characterization of the material excreted by the bacteria indicates that it s proteinaceous in nature. The interactions observed does not fit into any single category of interactions but can be explained as a combination of competition and indirect parasitism.
TL;DR: It was noteworthy that almost identical fatty acid composition was found in the cells grown on methanol-containing media and in thecells grown on media not containing methanols, in the both groups of methanl-utilizing bacteria.
Abstract: Composition of cellular fatty acids in methanol-utilizing bacteria was examined from the viewpoint of taxonomy. This group of bacteria showed a rather simple composition of cellular fatty acids, and was divided into two major groups on the basis of this composition. Pseudomonas methylotropha NCIB 10510, 10511, 10512, 10513, and 10515 showed the presence of a large amount of straight-chain saturated and unsaturated acids of C16:0 and C16:1, a small amount of straight-chain 3-hydroxy acid of C10:0, and a minor amount of other acids. Other methanol-utilizing bacteria, Pseudomonas extorquens NCIB 9399, Pseudomonas spp. NCIB 9133, 9686, and 10597, and Protaminobacter rubes NCIB 2879, showed the presence of a large amount of straight-chain unsaturated acid of C18:1, and a minor amount of other acids. Almost identical fatty acid composition was obtained from Microcyclus polymorphum NCIB 10516 and Hyphomicrobium variabile NCIB 10517, with the exception of the presence of cyclopropane acid of C19:0 and other unknown acids. It was noteworthy that almost identical fatty acid composition was found in the cells grown on methanol-containing media and in the cells grown on media not containing methanol, in the both groups of methanol-utilizing bacteria.
TL;DR: No clear cause-and-effect relationship between drug-supplemented animal feed and the presence of resistant bacteria in humans has been shown, and it was decided to focus on animal-tohuman spread of resistant bacterial strains and/or antibiotic resistance.
Abstract: nonpathogenic, they pose the threat of potential transfer of their resistance factors to pathogenic species. Furthermore, since antimicrobial drugs are used in animal and plant medicine, the spread of selected resistant organisms from one host to another may be important. The genetic information for antibiotic resistance is carried on R plasmids (R factors), which are pieces of extrachromosomal DNA. Many of these plasmids can be transferred between different species of bacteria [1]. Bacteria of all species may contain plasmids, and many different properties are encoded by plasmid DNA [2]. Antibiotics select resistant bacteria in animals, plants, and humans to whom the drug has been administered. Evidence has suggested animal-tohuman spread of resistant bacterial strains and/or antibiotic resistance, but no clear cause-and-effect relationship between drug-supplemented animal feed and the presence of resistant bacteria in humans has been shown. We therefore decided to
TL;DR: Genes conferring resistance to aminoglycoside-aminocyclitol antibiotics in three group D streptococcal strains, Streptococcus faecalis JH1 and JH6 and S. faecium JH7, and to chloramphenicol in JH 6 are carried by plasmids that can transfer to other S.Faecalis cells.
Abstract: Genes conferring resistance to aminoglycoside-aminocyclitol antibiotics in three group D streptococcal strains, Streptococcus faecalis JH1 and JH6 and S. faecium JH7, and to chloramphenicol in JH6 are carried by plasmids that can transfer to other S. faecalis cells. The aminoglycoside resistance is mediated by constitutively synthesized phosphotransferase enzymes that have substrate profiles very similar to those of aminoglycoside phosphotransferases found in gram-negative bacteria. Phosphorylation probably occurs at the aminoglycoside 3′-hydroxyl group. Plasmid-borne streptomycin resistance is due to production of the enzyme streptomycin adenylyltransferase, which, as in staphylococci and in contrast to that detected in gram-negative bacteria, is less effective against spectinomycin as substrate. Resistance to chloramphenicol is by enzymatic acetylation. The chloramphenicol acetyltransferase is inducible and bears a close resemblance to the type D chloramphenicol acetyltransferase variant from staphylococci. Images
TL;DR: It is demonstrated that metronidazole's antimicrobial activity against anaerobic bacteria is bactericidal and independent of growth rate, and that it involves the uptake and metabolism of the compound.
Abstract: The antimicrobial activity of metronidazole was investigated in anaerobic bacteria by use of time-viability studies. This antimicrobial agent has a rapid onset of bactericidal activity under proper reducing conditions. The bactericidal rates were not affected by inoculum size or nutritional requirements, nor by inhibition of growth and protein synthesis by chloramphenicol. Using supernatant fractions of actively growing cultures of susceptible organisms, we observed a disappearance of metronidazole and a loss of biological activity, but there was no significant change in preparations from resistant bacteria. The decrease in drug concentration with susceptible cells occurred during the time that its bactericidal action was being exerted. Extracts from susceptible organisms rapidly reduced the concentration of metronidazole, confirming previous observations which suggest that the drug acts as a terminal electron acceptor. Radioisotope experiments with [14C]metronidazole revealed that the compound was taken up by both resistant and susceptible bacteria, although there was a difference in rate and extent of accumulation. These studies demonstrate that metronidazole's antimicrobial activity against anaerobic bacteria is bactericidal and independent of growth rate, and that it involves the uptake and metabolism of the compound.
TL;DR: The demonstration of a de novo bacterial biosynthesis of a protein having similar antigenic and biophysical properties to those of the human trophoblastic hormone, has great biological implications, especially if its biosynthesis is proven only in bacterial strains growing in the presence of cancer cells in which it has already been demonstrated the existence of a similar antigen.
Abstract: By the use of specific antibody to human chorionic gonadotropin (CG) as well as to its beta-subunit, and the application of the indirect fluorescein-labeled and peroxidase-labeled antibody techniques, we have demonstrated the presence of a membrane (wall)-associated CG-similar immunoreactive protein in 15 strains of bacteria isolated from tissues of patients bearing malignant neoplasms. These microorganisms were classified as S. epidermidis, (12) E. coli (2), and a single strain of P. maltophilia (ATCC 13637). The absence of the CG-like antigen in other "cancer associated bacteria", Streptococcus faecalis (ATCC 12818) and Pseudomonas aeruginosa (from patient with cancer of colon), demonstrated that not every "cancer associated bacteria" has the capability to synthesize the trophoblastic-like protein. The negative results obtained with a number of "noncancer control" bacteria of known origin, obtained from ATCC and from clinical samples, strongly supported the idea that the existance of these CG-like protein producing microorganisms is not a ubiquitous finding. The demonstration of a de novo bacterial biosynthesis of a protein having similar antigenic and biophysical properties to those of the human trophoblastic hormone, has great biological implications, especially if its biosynthesis is proven only in bacterial strains growing in the presence of cancer cells in which we have already demonstrated the presence of a similar antigen. The explanation of the phenomenon is unknown. Because of their origin, the potential of "genetic exchange" with subsequent expression of the mammalian gene by the bacterial cells becomes a possibility. It is also possible that the gene coding for the CG-like protein is normally present but inactive or repressed in all bacteria.
TL;DR: It would appear that the soil coryneform bacteria possess similar survival characteristics in laboratory studies which could explain, in part, their ecological success in natural environments.
Abstract: Summary: Cultures of 16 coryneform bacteria were grown to late-exponential stage in nutrient media, washed, and starved in 30 mm-potassium phosphate buffer pH 7.0, with no external energy or carbon source. After 4 weeks starvation, 20 to 98% of each culture was still viable; after 8 weeks, 5 to 70% of each culture was still viable. Little change in cell shape or size was detected in Arthrobacter globiformis, A. nicotianae, Brevibacterium linens, Corynebacterium fascians, Mycobacterium rhodochrous and Nocardia roseum when studied by electron microscopy for up to 56 d, although there was a gradual disappearance of intracellular material. No resting structures were discernible. All organisms showed an immediate decrease in endogenous respiration to less than 1% of that observed during growth. A low basal level of endogenous metabolism equivalent to 0.01 to 0.03% of cellular carbon oxidized to CO2 h−1 was maintained for 56 d. Carbohydrate, intracellular pools, protein, ribonucleic acid and deoxyribonucleic acid were utilized at varying rates by different organisms during this period. All species were effective in maintaining 20 to 70% of their Mg2+ content during a 28 d starvation period in the absence of any external Mg2+. It would appear that the soil coryneform bacteria possess similar survival characteristics in laboratory studies which could explain, in part, their ecological success in natural environments.
TL;DR: It is concluded that C1 in an enzymatically active state can be bound directly to bacteria independently of antibody.
Abstract: The interaction of the first component of complement with two serum-sensitive strains of Escherichia coli and Klebsiella pneumoniae was studied. It could be demonstrated that highly purified C1, free of immunoglobulin G and immunoglobulin M, binds to E. coli or K. pneumoniae. C1 binding was also found with specifically absorbed human serum, after incubation of bacteria with normal serum in the presence of ethylenediaminetetraacetate or agammaglobulinemic serum; the number of C1 molecules taken up by the bacteria was not influenced, indicating that C1 binding was independent of naturally occurring antibodies. C1 bound to bacteria was still able to cleave C4, the natural substrate of C1. From these observations, it is concluded that C1 in an enzymatically active state can be bound directly to bacteria independently of antibody.
TL;DR: Results prove a relationship between impairment in bactericidal capacity and cellular activities of lysosomal enzymes, in which absence of enzyme activity occurred only in macrophages subjected to the dual insults of ozone exposure and ingested bacteria.
Abstract: The role of lysosomal enzymes in the inactivation of inhaled bacteria by alveolar macrophages was studied in rats infected with aerosols of Staphylococcus aureus and then exposed for 5 hr to 2.5 ppm of ozone to determine whether pollutant-induced defects in phagocytic killing were associated with reductions in enzyme activity. Rates of bacterial ingestion and the activities of cellular acid phosphatase and p-glucuronidase were measured simultaneously in in situ perfused right lungs by sequential staining of frozen sections for enzyme and bacteria. Quantitative measurements of enzyme activity within macrophages without ingested bacteria were made with a computer-controlled cytospectrophotometry system. Exposure to ozone resulted in diminished rates of bacterial clearance and ingestion, large increases in numbers of intra- and extracellular staphylococcal microcolonies, and an absence of enzyme activity for macrophages containing bacterial microcolonies. Enzyme activity was unimpaired in macrophages without ingested bacteria. These results, in which absence of enzyme activity occurred only in macrophages subjected to the dual insults of ozone exposure and ingested bacteria, prove a relationship between impairment in bactericidal capacity and cellular activities of lysosomal enzyme.
TL;DR: Biochemical and immunological data indicate, however, that both enzymes are different with respect to their native structure as well as the distribution of both types of hydrogenases.
TL;DR: Five new strains of yellow-pigmented, gram-negative, motile, hydrogen-oxidizing bacteria were isolated and each served as a host for simultaneously isolated bacteriophages, and six of the strains were characterized by a high degree of interstrain similarity and were found to be related to P. flava.
Abstract: Five new strains of yellow-pigmented, gram-negative, motile, hydrogen-oxidizing bacteria were isolated; each served as a host for simultaneously isolated bacteriophages. These isolates and two additional strains were compared with other gram-negative, hydrogen-oxidizing bacteria with respect to morphology; nutritional and biochemical properties; growth parameters; cytochrome content; pigment production; susceptibility to bacteriophages, bacteriostatic agents, and antibiotics; deoxyribonucleic acid base composition; and deoxyribonucleic acid-deoxyribonucleic acid homology. Six of the strains were characterized by a high degree of interstrain similarity and were found to be related to Pseudomonas flava. However, due to basic differences between these strains and P. flava, the former are regarded as comprising a new species for which, because of its moderate relationship to P. flava, the name Pseudomonas pseudoflava is proposed. The type strain of P. pseudoflava, GA3, has been deposited with the Deutsche Sammlung von Mikroorganismen in Gottingen under the number DSM 1034.