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PubMedDate not supplied

[Effect of normal and specific immune sera on neuraminidase activity].

We have got evidence that there is no antigenic relationship reflecting the structural similarity between neuraminidases synthesized by noncholera vibrios and Arthrobacter nicotianae. The cross-reactions between the enzymes and heterological antisera were not observed. Antibodies against the A. nicotianae neuraminidase inhibited the activity of the enzyme for a glycomacropeptide of milk whey and for components of the blood serum, and had no effect no the neuraminidase from noncholera vibrios. Antibodies against the neuraminidase of noncholera vibrios inhibited only the activity of the homologous enzyme. Upon gel-filtration on Sephadex G-200 the antibodies inhibiting the activity of the enzymes under study were found in the fraction of 7S-gamma-globulins.

Animals↗

PubMedDate not supplied

[Ultrastructure of resting cells of some non-spore-forming bacteria].

Using electron microscopy (ultrathin sections and freeze-fractures), we investigated the ultrastructure of the resting cells formed in the cultures of Micrococcus luteus, Arthrobacter globiformis, and Pseudomonas aurantiaca under conditions of prolonged incubation (up to 9 months). These resting cells included cyst-like forms that were characterized by complex cell structure and the following ultrastructural properties: (i) a thickened or multiprofiled cell wall (CW), typically made up of a layer of the preexisting CW and one to three de novo synthesized murein layers; (ii) a thick, structurally differentiated capsule; (iii) presence of large intramembrane particles (d = 180-270 A), occurring both on the PF and EF sides of the membrane fractures of M. luteus and A. globiformis; (iv) a peculiar structure of the cytoplasm, which was either fine-grained or lumpy (coarse-grained) in different parts of the cell population; and (v) a condensed nucleoid. Intense formation of cyst-like cells occurred in aged (2- to 9-month-old) bacterial cultures grown on diluted complex media or on nitrogen-, carbon-, and phosphorus-limited synthetic media, as well as in suspensions of cells incubated in media with sodium silicate. The general morphological properties, ultrastructural organization, and physiological features of cyst-like cells formed during the developmental cycle suggest that constitutive dormancy is characteristic of non-spore-forming bacteria.

Arthrobacter↗

PubMedDate not supplied

[Properties of the hexulose phosphate synthase of methylotrophic yeasts and bacteria].

Properties of hexulose phosphate synthase (HPS) were studied in extracts of the methanol assimilating yeast Candida methylica and the bacterium Arthrobacter globiformis B-175 assimilating methylated amines. HPS is an inducible enzyme which is localized in the soluble fraction of the cells. The effect of the pH of the reaction mixture, temperature, metal ions, and the concentration of substrates on the activity of HPS was studied. Properties of the enzyme were different in the yeast and the bacterium. The activity of HPS was strongly stimulated by ATP in C. methylica and was not affected in A. globiformis.

Adenosine Triphosphate↗

PubMedDate not supplied

[Experimental and mathematical modeling of population dynamics of rhizospheric bacteria under conditions of cadmium stress].

The method of membrane filters was used to study the population dynamics of bacteria belonging to the genera Arthrobacter, Flavobacterium, and Klebsiella in barley (Hordeum vulgare) rhizosphere under conditions of cadmium stress (5-15 mg Cd/g soil). Mathematical modeling allowed us to demonstrate that the phytoprotective effect is implemented via the following succession of events: the bacteria synthesize phytohormones (IAA and ethylene)-->root excretory activity increases-->the number of the bacteria in the rhizoplane grows-->the flux of bacteria migrating from the rhizoplane to the rhizosphere increases-->the number of bacteria binding cadmium ions in the rhizosphere grows-->the amount of free ions entering the plant decreases. Among the bacteria studied, K. mobilis 880 displayed the highest migration and immobilization activity and the best survival rate under conditions of cadmium stress. Consequently, K. mobilis 880 is recommended for use in biopreparations for stimulating plant growth under conditions of heavy metal pollution.

Agriculture↗

PubMedDate not supplied

[Quantitative description of microbial growth in a batch culture depending on the physiologic state of inocula].

The dynamics of biomass production and the respiration rate of five microorganisms grown as batch cultures were studied in detail. Cell suspensions with a known physiological state, i.e. chemostat cultures grown at a particular D value, as well as quasi steady-state populations cultivated with slow feeding and long energy-source starvation were used as inocula. The microorganisms were arbitrary subdivided into two groups. The biomass of Pseudomonas fluorescens, Bacillus subtilis and Debaryomyces formicarius accumulated smoothly with a monotonic rise of the specific growth rate to the upper level of microns. A distinct inverse correlation was established between the duration of the lag phase and the specific growth rate of the inoculum. Arthrobacter globiformis and Lipomyces tetrasporus were characterised by biphase growth referred to as false diauxia: glucose was accumulated without its oxidation during the first phase, and actual growth (just as in the first group of microorganism) occurred during the second phase. Most of the results are satisfactorily described by a simplified modification of the synthetic chemostat model.

Arthrobacter↗

PubMed1991

The organic functional group in copper-containing amine oxidases. Resonance Raman spectra are consistent with the presence of topa quinone (6-hydroxydopa quinone) in the active site.

Resonance Raman spectroscopy has been used to probe the structure of the organic cofactor in copper-containing amine oxidases from bovine plasma, porcine kidney, pea seedlings, and the bacterium Arthrobacter P1. The enzymes were first derivatized with phenylhydrazine or p-nitrophenylhydrazine; resonance Raman spectra were obtained on the intact derivatized enzymes and on a derivatized active-site peptide isolated from bovine plasma amine oxidase. Spectra of the intact amine oxidase phenylhydrazones are practically identical, consistent with the enzymes examined containing a similar cofactor. Only minor frequency shifts and some intensity variations are detected between the resonance Raman spectra of intact bovine plasma amine oxidase and the isolated peptide. These spectral perturbations are attributable to differences in the micro-environment between the intact, folded protein and the isolated small peptide in aqueous solution. This rules out the possibility that a new structure is formed during the isolation of the derivatized active-site peptide. Importantly, the resonance Raman spectra of the phenylhydrazine and p-nitrophenylhydrazine derivatives of the bovine plasma amine oxidase peptide are identical to the spectra of the corresponding derivatives of topa quinone (6-hydroxydopa quinone). Hence these data provide strong, independent support for the recent identification of topa as the organic functional group in bovine plasma amine oxidase (Janes, S. M., Mu, D., Wemmer, D., Smith, A. J., Kaur, S., Maltby, D., Burlingame, A. L., and Klinman, J.P. (1990) Science 248, 981-987).

Amine Oxidase (Copper-Containing)↗

PubMedDate not supplied

[Combined immobilized cultures producing fibrinolytic proteinases].

The authors obtained combined immobilised systems composed of a culture producing fibrinolytic proteinases and a stimulating strain. The optimal ratio between the two cultures in gel was selected at a high starting cell density. Highly stable immobilised cultures were produced by growing the cells in gel particles. The interrelationship of the partners was studied in the binary immobilised culture. The biosynthetic activity of the system fell down to the level of a monoculture when the cells of the stimulating strain were eliminated from gel. The producing and stimulating strains are at equilibrium in associative immobilised cultures obtained by growing the cells in gel, and Arthrobacter is not eliminated. The mechanism of biosynthesis stimulation in a combined immobilised culture has been studied. Apparently, the procedure of immobilisation and the action of a stimulating compound exert the synergistic effect.

Arthrobacter↗

PubMedDate not supplied

[Esterase activity of hydrocarbon-oxidizing bacteria].

The activity of esterase was studied in bacteria oxidizing hydrocarbons and belonging to the genera Rhodococcus, Arthrobacter and Pseudomonas. Indophenyl acetate was used as a substrate of the reaction catalysed by the enzyme. Exocellular esterases were not found. Endocellular esterases differed in their activity and thermostability both among the genera and among species of one and the same genus.

Arthrobacter↗

PubMed1986

Enzymes of vitamin B6 degradation. Purification and properties of pyridoxine 5'-dehydrogenase (oxidase).

Isolation and identification of a soil bacterium, Arthrobacter Cr-7, that grows with pyridoxine as a sole source of carbon and nitrogen are described. An inducible pyridoxine 5'-dehydrogenase (oxidase) (EC 1.1.99.9) that catalyzes conversion of pyridoxine to isopyridoxal, Pyridoxine + X----isopyridoxal + XH2, the first step in utilization of pyridoxine as a growth substrate by this organism, was purified about 520-fold to homogeneity. The enzyme (Mr = 112,000) is a dimer of probably identical subunits and requires FAD (KD(app) = 0.24 microM) as coenzyme. It oxidizes only pyridoxine (Km = 0.18 mM) and a few related compounds (4-deoxypyridoxine, pyridoxamine, pyridoxal) that contain a free 5-CH2OH group and utilizes oxygen (Km = 0.28 mM), 2,6-dichloroindophenol, or quinones, but not NAD+ or NADP+, as hydrogen acceptors (X in reaction above). With pyridoxine and oxygen as substrates, the enzyme has a broad pH optimum (from pH 7.0 to 8.3), a Vmax of 11.9 mumol X min-1 X mg-1, and a turnover number of 22 s-1 at 25 degrees C. The enzyme is strongly inhibited by sulfhydryl reagents. Except for its substrate specificity, these properties do not differ greatly from those of other flavin-dependent oxidases.

Alcohol Oxidoreductases↗

PubMed1986

Enzymes of vitamin B6 degradation. Purification and properties of isopyridoxal dehydrogenase and 5-formyl-3-hydroxy-2-methylpyridine-4-carboxylic-acid dehydrogenase.

Two NAD+-dependent, highly specific pyridine-5-aldehyde dehydrogenases, 5-formyl-3-hydroxy-2-methylpyridine-4-carboxylic-acid (Compound 1) dehydrogenase and isopyridoxal dehydrogenase, were purified to homogeneity from Pseudomonas MA-1 and Arthrobacter Cr-7, respectively. Both enzymes are induced in response to growth of the organisms on pyridoxine and catalyze steps in the degradation of this compound by these organisms. Compound 1 dehydrogenase (Mr = 65,000) contains two subunits of equal size with methionine as the NH2-terminal amino acid and acts optimally at pH 7.8-8.5. It catalyzes with equal facility (turnover number = 400-670 s-1 molecule-1) both the oxidation of Compound 1 (Km = 65 microM) by NAD+ (Km = 25 microM) to 3-hydroxy-2-methylpyridine-4,5-dicarboxylic acid and the reduction of Compound 1 by NADH (Km = 20 microM) to 4-pyridoxic acid and appears to act as a true dismutase. The possible advantage to the organism of its ability to act as a dismutase is discussed briefly. No oxidation of 4-pyridoxic acid by this enzyme was observed. Isopyridoxal dehydrogenase (Mr = 242,000) contains four subunits of equal size, again with methionine at the NH2 terminus. At its optimal pH of 8.0-8.6, it catalyzes the oxidation of isopyridoxal (Km = 40 microM, turnover number = 10 s-1 molecule-1) by NAD+ (Km = 40 microM) to a mixture of 5-pyridoxic acid and 5-pyridoxolactone, which are produced in constant ratio throughout the course of the reaction. Formation of the two products, although unusual, is readily understandable in terms of the structure of isopyridoxal in solution or the structure of a possible acyl-enzyme intermediate in the oxidative reaction.

Alcohol Oxidoreductases↗

PubMed1986

[The use of bioelectrochemical systems in steroid biosynthesis].

The feasibility of electrosynthesis involving the use of biocatalysts has been demonstrated in a model reaction of hydrocortisone oxidation to prednisolone catalyzed by Arthrobacter globiformis cells. Electrochemical regeneration of phenazine methosulfate, an artificial electron acceptor, was performed, using electrodes made of different materials. Transformation products were analyzed by high performance liquid chromatography.

Arthrobacter↗

PubMedDate not supplied

[Characteristics of the development and biosynthetic activity of a mixed culture of microorganisms].

The growth of microbial populations and their biosynthesis of proteinases with the fibrinolytic activity were studied in an artificial ecosystem composed of a strain producing the enzymes (Nocardia minima 1) and a zero strain (Arthrobacter citreus VKM 654). The microorganisms in the association were shown to interact in terms of amensalism via metabolites if the enzyme-producing strain dominated.

Arthrobacter↗

PubMed1985

Enzymes of vitamin B6 degradation. Purification and properties of two N-acetylamidohydrolases.

alpha-(N-Acetylaminomethylene)succinic acid hydrolase (Compound A hydrolase, EC 3.5.1-) and alpha-hydroxymethyl-alpha'-(N-acetylaminomethylene)succinic acid hydrolase (Compound B hydrolase, EC 3.5.1-) were purified to homogeneity from Pseudomonas MA-1 and Arthrobacter Cr-7, respectively. The two inducible enzymes catalyze Reactions 1 and 2, respectively, which release the first generally useful anabolic intermediates during growth of these organisms with (formula; see text) pyridoxine as a sole source of carbon and nitrogen. Compound A hydrolase is a monomeric protein of Mr 32,500 with aspartic acid as its NH2-terminal residue. Compound B hydrolase (Mr congruent to 205,000) is a multimer containing probably six identical subunits with glycine as the NH2 terminus. The two enzymes have quite different amino acid analyses, although both are high in Asx and Glx, lack tryptophan, and show similar stabilities to pH and temperature. Compound A hydrolase has a pI of 4.4, a Km of 3.3 microM, and a Vmax of 3.1 mumol X min-1 X mg-1 at pH 6.5 and 25 degrees C; no analogue substrates were found. Compound B hydrolase has a pI of 4.2, a Km of 25 microM, and a Vmax of 3.8 mumol X min-1 X mg-1 at 25 degrees C and pH 7.0; it also hydrolyzes Compound A slowly. Both enzymes are inhibited competitively by di- and tricarboxylic acids, itaconic acid being among the most effective. Sulfite inhibits both enzymes by a time-dependent mechanism not yet understood. The two amidases appear to differ greatly in architecture despite the similarity in properties and in the overall reactions they catalyze.

Amidohydrolases↗

PubMedDate not supplied

[Microbiologic studies of a spodumene deposit].

A wide spectrum of heterotrophic and autotrophic microorganisms was detected in the zones of decomposition of spodumene and bed rocks, pegmatites and shales, in the spodumene deposit. The following aerobic microorganisms which did not from spores predominated in the deposit: Arthrobacter globiformis, A. pascens, A. simplex, Nocardia globerula, Pseudomonas fluorescens, Ps. putida, Ps. testosteronii. The following specific bacterial groups were found: thionic, sulfate reducing, and nitrifying bacteria. Degradation of spodumene and bed rocks was found to occur in moist regions containing cracks; it was accompanied with a decrease in pH. A possible role of microorganisms in decomposition of spodumene as well as removal of elements is discussed.

Aluminum Silicates↗

PubMed1971

Bacteriology of manganese nodules. V. Effect of hydrostatic pressure on bacterial oxidation of MnII and reduction of MnO2.

It was experimentally demonstrated that two strains of Arthrobacter 37, one growing at 25 C and the other at 5 C, could catalyze Mn(II) oxidation at hydrostatic pressures well in excess of the pressure encountered by the parent culture in its original habitat in the ocean (80 atm). The strain grown at 5 C showed an increase in temperature optimum for manganese oxidation with increase in pressure. It was like-wise experimentally shown that induced Bacillus 29 without added ferricyanide and uninduced Bacillus 29 with added ferricyanide could catalyze MnO(2) reduction at hydrostatic pressures in excess of the pressure encountered by this organism in its original habitat (187 atm). The uninduced Bacillus 29, in the presence of ferricyanide, was active over a wider range of pressures (1 to 1,000 atm) than the induced Bacillus 29 in the absence of ferricyanide (1 to 467 atm). At corresponding pressures, the uninduced culture was also considerably more active than the induced culture. Special techniques were developed for measuring Mn(II)-oxidizing and MnO(2)-reducing activity under pressure.

Arthrobacter↗

PubMed1981

Effect of microorganisms on the phytotoxicity of herbicides. VI. Modification of venzar activity by bacterial cultures.

Interactions between two bacterial strains and venzar were compared. It was found that the mechanism of interactions is various and causes the modification of herbicide phytotoxicity. Metabolites of Bacillus subtilis 72 interfered with herbicide by affecting physiological processes in plant tissues and enhancing its inhibitory influence. Arthrobacter sp. 18 strain decreased the phytoinhibitory effect of herbicide due to conjugation with the carrier from venzar.

Arthrobacter↗

PubMed1980

[1H-NMR-spectroscopic evidence for the release of N-acetyl-alpha-D-neuraminic acid as the first product of neuraminidase action (author's transl)].

The 1H-NMR spectroscopy was used to study the anomeric configuration of N-acetyl-D-neuraminic acid released by the action of neuraminidase. The hydrolysis of NeuAcalpha 2 leads to 3 Gal-beta 1 leads to 4Glc (20mM) by the enzymes of Clostridium perfringens and Arthrobacter ureafaciens (50 mU, 150 mU and 800 mU, respectively) in 50mM Na/K-phosphate buffer pD 5.4 was observed by recording the spectra. On the basis of the characteristic signals of the protons at C-3 (alphaNeuAc: delta[H(3e)] = 2.72, delta[H(3a)] = 1.64; betaNeuAc: delta[H(3e)] = 2.25, delta[H(3a)] = 1.84) the product of the enzymatic cleavage was identified to be the N-acetylneuraminic acid in the alpha-anomeric form. Two hypotheses are discussed to explain how the enzymatic hydrolysis may occur and how N-acetyl-alpha-D-neuraminic acid leaves the catalytic site of the neuraminidases with retention of the C-2 configuration.

Arthrobacter↗

PubMed1981

[1H-NMR spectroscopy--a potent method for the determination of substrate specificity of sialidases (author's transl)].

We describe here the application of 1H-NMR spectroscopy to determine the substrate specificity of sialidases using a 1:1 mixture of NeuAc alpha 2-3Gal beta 1-4Glc and NeuAc alpha 2-6Gal beta 1-4Glc, one viral and five bacterial sialidases. This method utilizes the separate signals in NMR spectra, characteristic for the different alpha ketosidically linked NeuAc residues and also for bound and free NeuAc. The signals generally most suitable for these purposes are those of H3a, H3e and NCOCH3. By observation and integration of these signals we can follow--qualitatively and quantitatively--which and how many NeuAc residues of the substrates are hydrolized. In contrast to the generally used colorimetric tests it is now possible to investigate with this method substrates containing two or more NeuAc residues and to determine the corresponding rate constants for hydrolysis of the differently bound NeuAc molecules. The six sialidases used show large differences in their specificity as compared with our "model substrate": The sialidase from fowl plague virus hydrolizes NeuAc alpha 2-3Gal beta 1-4Glc nearly 18 times and the enzyme from Clostridium perfringens four times, from Vibrio cholerae two times faster than NeuAc alpha 2-6Gal beta 1-4Glc. On the contrary, the sialidase from Arthrobacter ureafaciens hydrolizes the alpha 2-6 linkage six times faster than the alpha 2-3 linkage. The sialidases from Bifidobacterium show no obvious differences in their specificities relative to the linkage.

Actinomycetaceae↗