Formation of resting forms of arthrobacter globiformis in autolyzing cell suspensions

Under conditions of the spontaneous or induced autolysis of thick cell suspensions,Arthrobacter globiformis strains produced cells exhibiting features typical of resting microbial forms. The number of viable resting cells was greater under conditions of induced rather than spontaneous autolysis. The thermoresistance of the resting cells of A.globiformis strains isolated from 2-to 3 million-year-old permafrost was higher than that of the collectionA. globiformis strain.     

Nitrogen metabolism inRhodopseudomonas globiformis

Rhodopseudomonas globiformis strain 7950 grew with a variety of amino acids, urea, or N₂ as sole nitrogen sources. Cultures grown on N₂ reduced acetylene to ethylene; this activity was absent from cells grown on nonlimiting NH ₄ ⁺ . Glutamate dehydrogenase could not be detected in extracts of cells of strain 7950, although low levels of an alanine dehydrogenase were present. Growth ofR. globiformis on NH ₄ ⁺ was severely inhibited by the glutamate analogue and glutamine synthetase inhibitor, methionine sulfoximine. High levels of glutamine synthetase (as measured in the -glutamyl transferase assay) were observed in cell extracts of strain 7950 regardless of the nitrogen source, although N₂ and amino acid grown cells contained somewhat higher glutamine synthetase contents than cells grown on excess NH ₄ ⁺ . Levels of glutamate synthase inR. globiformis were consistent with that reported from other phototrophic bacteria. Both glutamate synthase and alanine dehydrogenase were linked to NADH as coenzyme. We conclude thatR. globiformis is capable of fixing N₂, and assimilates NH ₄ ⁺ primarily via the glutamine synthetase/glutamate synthase pathway.Abbreviations GS glutamine synthetase - GOGAT Glutamineoxoglutarate aminotransferase - GDH Glutamate dehydrogenase - ADH Alanine dehydrogenase - MSO Methionine sulfoximine     

Bacterial Succession on n-Alkanes under the Conditions of Sulfate Reduction

The dynamics of species composition of a hydrocarbon-oxidizing bacteriocenosis of a ground suspension of the Mozhaisk Reservoir has been studied. The bacteriocenosis was undergoing development in a paraffin film (model association composed of sulfate-reducing bacteria and hydrocarbon-oxidizing bacteria). The type of bacterial succession did not depend on the depth, from which ground samples were collected. Two microbial species (Pseudomonas sp. andArthrobacter globiformis) were absolutely dominant. Pseudomonas sp. was dominant at the early and intermediate stages of the succession, whereas A. globiformis was present in the hydrocarbon-oxidizing bacteriocenosis throughout the whole period of the succession. There was a trend toward a gradual increase in the ratio of A. globiformis, and, by the end of the experiment, Pseudomonas sp. was replaced by A. globiformis almost completely. The bacterial species Micrococcus sp. and Rhodococcus erythropolis were minor components of the hydrocarbon-oxidizing bacteriocenosis under the conditions of sulfate reduction. The succession of species of hydrocarbon-oxidizing bacteria in the paraffin film of the model association reflects both the life strategy of the bacterial species under study and the degree of their tolerance to products of sulfate reduction.     

The lipopolysaccharides of Rhodospirillum rubrum,Rhodospirillum molischianum,and Rhodopila globiformis

The cell wall lipopolysaccharides from three phototrophic species of the alpha₁-group of Proteobacteria, Rhodospirillum rubrum, Rhodospirillum molischianum, and Rhodopila globiformis were isolated and chemically characterized. Sodium deoxycholate polyacrylamide gel electrophoresis patterns revealed that the lipopolysaccharides of all three species possess O-chains. They are composed of repeating units only in R. molischianum and R. globiformis. The presence of l-glycero-d-mannoheptose and 2-keto-3-deoxyoctonate indicated core structures in all three lipopolysaccharides. Glucosamine was found as backbone amino sugar in lipid A of R. molischianum and R. rubrum, while R. globiformis has 2,3-diaminoglucose as backbone amino sugar. The latter species also differed from the two former ones in its content of hydroxy fatty acids (3-OH-14:0, 3-OH-16:0 in R. rubrum and R. molischianum and 3-OH-14:0, 3-OH-18:0 and 3-OH-19:0 (possibly iso- or anteisobranched) in R. globiformis).Abbreviations DOC-PAGE sodium deoxycholate polyacrylamide gel electrophoresis - GC/MS combined gas-liquid chromatography/mass spectrometry - KDO 2-keto-3-deoxyoctonate     

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 cultures of Micrococcus luteus, Arthrobacter globiformis, and Pseudomonas aurantiaca under conditions of prolonged incubation (up to 9 months). These resting cells included cystlike forms that were characterized by a 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) the presence of large intramembrane particles (d = 180–270 Å), occurring both on the PF and EF faces 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 cystlike 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 cell suspensions incubated in media with sodium silicate. The general morphological properties, ultrastructural organization, and physiological features of cystlike cells formed during the developmental cycle suggest that constitutive dormancy is characteristic of non-spore-forming bacteria.     

Transient behavior and time aspects of intermittently and continuously fed bacterial cultures with regard to filamentous bulking of activated sludge

Summary Pure culture transient experiments with Arthrobacter globiformis and Sphaerotilus natans revealed that the floc-forming species A. globiformis can adapt better to intermittent feeding (I-feeding) than the filamentous species S. natans. The floc-forming bacterium showed a larger overcapacity for substrate uptake, a larger accumulation of reserves (polysaccharides and poly--hydroxybutyric acid) and a more efficient mobilization of these polymers. As a consequence A. globiformis became dominant in an I-fed dual culture of S. natans and A. globiformis. The transient behaviour of filamentous continuously fed (C-fed) sludge was similar to the response of S. natans. Consequently, I-feeding of activated sludge could prevent the excessive growth of filamentous bacteria. I-fed sludge, showed a higher overcapacity, the accumulation of more reserves and a shorter lag phase in protein synthesis than C-fed activated sludge, during the transient response, after a pulse dose of substrate. However, to be effective in the control of bulking, the frequency of I-feeding should allow for a sufficiently long endogenous phase. In addition the available fraction of the COD is important in the optimization of I-feeding as a control strategy for filamentous bulking.     

The mutual growth ofArthrobacter globiformis andPseudomonas fluorescens in gamma-sterilized soil

Summary Arthrobacter globiformis andPseudomonas fluorescens were grown separately and together in flasks containing soil sterilized by gamma-irradiation. If the soil was held at 60% of its waterholding capacity (W.H.C.) and 25°C the viable cell yield of the 2 organisms in pure culture was approximately equal in 4 days while in mixed culture neither organism predominated and the total yield was about the same as in either pure culture. The pseudomonad dominated the mixed cultures when the incubation temperature was 10°C, when the soil was saturated and when glucose was added to the soil. The arthrobacter dominated the mixed culture when soil moisture was decreased to 40% W.H.C. The 10-day oxygen uptake by the 2 organisms grown together in sterile soil was much less than that shown by an inoculum prepared from a soil dilution.A. globiformis took up less oxygen when grown in the sterile soil than didP. fluorescens. In these short-term experimentsA. globiformis did not demonstrate competitive capabilities which would explain its more frequent occurrence in unamended soil thanP. fluorescens. This work was supported by grant A-1702 from the National Research Council of Canada, and by assistance from Ontario Department of Agriculture and Food.     

Activity of diaminopimelic acid decarboxylase in bacteria producing lysine

Activity of DAP-decarboxylase in lysine overproducing strains of Micrococcus luteus, M. varians and Arthrobacter globiformisLb reached the highest level during the end of the exponetial phase of growth and remained at the same high level during the stationary phase of growth when major bulk of lysine was accumulated. In comparison in a lysine non-producing strain of Arthrobacter globiformis I ₄ the activity of the same enzyme was low. DAP-decarboxylase of these three lysine overproducers has two specialities, persistence during the stationary phase and insensivity to repression by exogenous lysine.     

Gratuitous induction of xanthine oxidase by 5,6-diaminouracil in continuously grown cells of Arthrobacter globiformis M4

Summary 5,6-Diaminouracil (DAU), was found to be a gratuitous inducer of xanthine oxidase (XO) in Arthrobacter globiformis M4. Synthesis of urate oxidase was not induced by this compound. Preparation of a biocatalyst rich in XO could be achieved by exposing continuously grown cells to low concentrations of DAU.     

Transformation of Synechococcus with a gene for choline oxidase enhances tolerance to salt stress

Choline oxidase, isolated from the soil bacterium Arthrobacter globiformis, converts choline to glycinebetaine (N-trimethylglycine) without a requirement for any cofactors. The gene for this enzyme, designated codA, was cloned and introduced into the cyanobacterium Synechococcus sp. PCC 7942. The codA gene was experssed under the control of a strong constitutive promoter, and the transformed cells accumulated glycinebetaine at intracellular levels of 60–80 mM. Consequently the cells acquired tolerance to salt stress, as evaluated in terms of growth, accumulation of chlorophyll and photosynthetic activity.     

Sulfate assimilation in Rhodopseudomonas globiformis

Rhodopseudomonas globiformis is able to grow on sulfate as sole source of sulfur, but only at concentrations below 1 mM. Good growth was observed with thiosulfate, cysteine or methionine as sulfur sources. Tetrathionate supported slow growth. Sulfide and sulfite were growth inhibitory. Growth inhibition by higher sulfate concentrations was overcome by the addition of O-acetylserine, which is known as derepressor of sulfate-assimilating enzymes, and by reduced glutathione. All enzymes of the sulfate assimilation pathway. ATP-sulfurylase, adenylylphosphate-sulfotransferase, thiosulfonate reductase and O-acetylserine sulfhydrylase are present in R. globiformis. Sulfate was taken up by the cells and the sulfur incorporated into the amino acids cysteine, methionine and homocysteine. It is concluded, that the failure of R. globiformis to grow on higher concentrations of sulfate is caused by disregulation of the sulfate assimilation pathway. Some preliminary evidence for this view is given in comparing the activities of some of the involved enzymes after growth on different sulfur sources and by examining the effect of O-acetylserine on these activities.Abbreviations DTE dl-dithioerythritol - APS adenosine 5-phosphosulfate, adenylyl sulfate - PAPS 3-phosphoadenosine 5-phosphosulfate, 3-phosphoadenylylsulfate     

Effect of quinocitrinines from the fungus <Emphasis Type="Italic">Penicillium citrinum</Emphasis> on the respiration of yeasts and bacteria

We studied the effect of quinocitrinines on the respiratory activity of yeasts (Yarrowia lipolytica) and bacteria (Arthrobacter globiformis). Quinocitrinines were shown to activate respiration of native cells in both types of organisms. Studies of yeast mitochondria showed that quinocitrinine exerts an uncoupling effect on oxidative phosphorylation, which activates the respiration, reduces the respiratory control, and decreases the ADP/O ratio. Experiments with intact mitochondria and native cells of Arthrobacter globiformis revealed that quinocitrinine decreases the membrane potential. The uncoupling effect likely constitutes a mechanism of the antibiotic activity of quinocitrinines.     

The Dynamics of the Size and Structure of the Soil Bacterial Complex in the Presence of Azobenzene

Azobenzene exerted no significant effect on the dynamics and the species composition of the saprophytic soil bacterial complex, which remained almost the same as in the control and was characterized by the predominance of Curtobacteriumsp., Arthrobacter globiformis, and Bacillus megateriumin all stages of succession. Some heterotrophic bacteria were found to be able to accumulate azobenzene. Bacillus cereusand Bac. polymyxadegraded azobenzene during their cultivation in nutrient media.     

PHILLIPOPTERIS GEN. NOV.—ANATOMICALLY PRESERVED SPORANGIAL FRUCTIFICATIONS FROM THE UPPER PENNSYLVANIAN OF THE APPALACHIAN BASIN

The discovery of a new type of sporangial fructification in coal balls from the Upper Pennsylvanian of Ohio provides the basis for describing Phillipopteris globiformis gen. et sp. nov. Sporangia are borne terminally on up to two orders of branching axes. Penultimate axes branch pinnately to produce irregularly branched ultimate axes. Sporangial wall cells are of a single type and show no specialization for dehiscence. Spores are radial and trilete, and reminiscent of the sporae dispersae genus Dictyotriletes. Phillipopteris increases our knowledge of diversity among fernlike plants from the late Paleozoic, and shares several features with Sclerocelyphus Mamay.     

Synthesis of Anabiosis Autoinducers by Non-Spore-Forming Bacteria as a Mechanism Regulating Their Activity in Soil and Subsoil Sedimentary Rocks

Non-spore-forming bacteria of the genera Arthrobacterand Micrococcus, isolated from permafrost subsoil, were found to produce greater amounts of the d ₁extracellular factor than closely related collection strains isolated from soil. The effect of this factor, responsible for cell transition to anabiosis, was not species-specific. Thus, the d ₁preparation isolated from the culture liquid of the permafrost isolate Arthrobacter globiformis245 produced an effect on the collection strain Arthrobacter globiformisB-1112 and also on Micrococcus luteusand Bacillus cereus.The d ₁preparation from the permafrost isolate of Arthrobacterdiffered from the chemical analogue of this factor, 4-n-hexylresorcinol, in the level of the induced cell response, which may have resulted from different cell sensitivity to various homologs of alkylhydroxybenzenes contained in the d ₁preparation. Thus, additional evidence was obtained indicating that autoregulation of bacterial growth and development is implemented at the level of intercellular interactions in microbial communities. Abundant production of the d ₁anabiosis-inducing factors by bacteria isolated from permafrost subsoil is probably a result of special antistress mechanisms responsible for the survival of these bacteria under extreme conditions of natural long-term cooling.     

The 1(2)-Dehydrogenation of Steroid Substrates by Nocardioides simplex VKM Ac-2033D

The bacterium formerly known asArthrobacter globiformis 193 has high 1(2)-dehydrogenase activity toward pharmaceutically important steroids, 9(11)-dehydrocortexolone in particular. The complex analysis of the morphostructural, physiological, biochemical, and phylogenetic properties of this bacterium allowed us to reclassify it into Nocardioides simplex (N. simplex VKM Ac-2033D).     

Influence of antibiotics and trace salts on lysine production by arthrobacter globiformis

A hydrocarbon utilizing strain of Arthrobacter globiformis Lb isolated from local soil has been found to yield lysine 3.4 g l^?1, keeping the medium optimal for pH, C- and N-sources. Addition of antibiotics and micronutrients to that optimal media stimulated cell growth and enhanced lysine yield.     

The role of thiosulfate in sulfur metabolism of Rhodopseudomonas globiformis

Rhodopseudomonas globiformis is able to assimilate both sulfur moieties of thiosulfate. During growth on ³⁵S-labelled thiosulfate the amino acids cysteine, homocysteine and methionine were labelled. The bulk of thiosulfate, however, was oxidized to tetrathionate and accumulated in the medium. A thiosulfate: acceptor oxidoreductase was partially purified and characterized. The enzyme oxidized thiosulfate to tetrathionate in the presence of ferricyanide. A c-type cytochrome isolated from this organism was reduced by this enzyme.     

Rat Stem-Cell Leukemia Gene Expression Increased during Testis Maturation

Histamine oxidase (EC class 1.4.3) was found in cells of Arthrobacter globiformis IFO 12137 (ATCC 8010) grown on histamine. The enzyme purified to a specific activity of 9.4units/mg had a purity of at least 80%. The enzyme oxidized histamine with concomitant formation of H₂O₂. Phenylethylamine, dopamine, aromatic monoamines, and aliphatic mono- and diamines were oxidized at lower rates. Cu²⁺-chelators inhibited the enzyme, indicating that the enzyme is Cu²⁺-dependent. Carbonyl-blocking reagents also inhibited the enzyme. The enzyme catalyzed the Nitro Blue Tetrazolium/glycinate reaction, which is characteristically catalyzed by quinones and quinoproteins. These results strongly suggest that the enzyme contains a quinonoid cofactor.