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PubMed1977

The structure of the branching point between acidic polysaccharide and peptidoglycan in Micrococcus lysodeikticus cell wall.

An acidic polysaccharide fraction composed of glucose and N-acetylmannosaminuronic acid with a small portion of peptidoglycan was isolated by enzymic digestion and subsequent ECTEOLA-cellulose chromatography from the cell walls of Micrococcus lysodeikticus. On mild acid treatment, the fraction became Morgan-Elson positive and formed the Morgan-Elson chromogen on heating with phosphate buffer (pH 7). The product of mild acid treatment released inorganic phosphate on treatment with phosphomonoesterase. After gel-chromatography on Sephadex G-25 and DE-32, the acidic polysaccharide fraction contained less glucosamine than muramic acid. By reduction of this fraction with borohydride, a part of the glucosamine was converted into glucosaminitol. Based on these results, it is suggested that the acidic polysaccharide is linked to glucosamine by a (1-3) linkage, which is linked to the 6 position of a muramic acid residue by a phosphodiester linkage.

Amino Acids↗
PubMed1977

Micrococcus luteus correndonucleases. I. resolution and purification of two endonucleases specific for DNA containing pyrimidine dimers.

Five peaks of endonuclease activity showing a preference for ultraviolet-damaged DNA have been chromatographically identified from extracts of Micrococcus luteus. They are numerically designated as I to V in order of their elution from phosphocellulose (Whatman P-11) columns. The first two of these peaks have been highly purified by a combination of gel filtration and affinity chromatography and are catalytically homogeneous judging from their effect on transforming DNAs. Peak I, which has an isoelectric point of 4.7, is heat-stable, requires high ionic strength for optimal activity, acts with equal facility on ultraviolet-irradiated native and denatured DNA, and has been designated as Py pyrimidine dimer Py correndonuclease I. Peak II which has a pI value of 8.7, is heat-labile, is inhibited by high ionic strength, acts on ultraviolet-irradiated native but not denatured DNA, and has been designated as Py pyrimidine dimer Py correndonuclease II. Both enzymes are inhibited by Ca2+ and Zn2+, do not show any cofactor or sulfhydryl requirement, act optimally between pH 7.0 and 7.4, and have molecular weights between 11,000 and 15,000. Py pyrimidine dimer Py correndonuclease I requires a dose about 1.6 times that for Py pyrimidine dimers Py correndonuclease II for incision saturation of irradiated phiX174 RFI DNA.

Chromatography, Gel↗
PubMed1977

Micrococcus luteus correndonucleases. III. Evidence for involvement in repair in vivo of two endonucleases specific for DNA containing pyrimidine dimers.

Involvement of Py pyrimidine dimers Py correnconucleases I and II in repair of ultraviolet radiation damage in vivo by Micrococcus luteus has been demonstrated by their absence in the ultraviolet-sensitive mutant DB-7 derived by treatment of the wild type parent with N-methyl-N'-nitro-N-nitrosoguanidine. The necessity for their combined action in DNA repair in M. luteus is shown by: (a) reactivation of ultraviolet-damaged phiX174 RFI DNA in incision-defective hosts after in vivo treatment with both enzymes, (b) correlation between survival after ultraviolet irradiation and the level of the two enzymes, and (c) increased levels of repair synthesis after ultraviolet irradiation of toluenized cells DB-400 with wild type correndonuclease levels when compared with the transformant DB-200 and the mutant DB-7, which lack one or both enzymes.

DNA Repair↗
PubMedDate not supplied

[Sensitivity of dissociation variants of Micrococcus luteus to the action of delta-endotoxins of Bacillus thuringiensis].

Endotoxins of Bacillus thuringiensis subsp. tenebrionis produced an antibiotic effect on three out of the four species of micrococci tested, showing an activity of 10-23 units/mg, comparable with that of bacitracin. The R variants of Micrococcus luteus were more than twice as resistant to the action of delta-endotoxins as cells of the S and M types. Enhanced growth of the tested microorganisms at concentrations of antibiotics large enough to inhibit the growth of the S and M variants, but insufficient to suppress the R-variant, was shown to be determined by the intense development of the latter variant.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Lysis of Micrococcus lysodeikticus protoplasts by gramicidin S derivatives].

Gramicidin S derivatives with the substituted amino groups of ornithines (carbamoylgramicidin and diacetylgramicidin) possess nearly the same level of the lytic activity when acting on Micrococcus lysodeikticus protoplasts in a 1 M sucrose solution as the original antibiotic. The lytic activity of gramicidin S and these derivatives considerably increases in a solution of sucrose in phosphate buffer. The dependence of the lytic activity of gramicidin on its concentration is of a complex character: two "peaks" of activity and a region of "nonlyzing" concentrations. The lytic activity of gramicidin derivatives with substituted amino groups directly depends on the concentration. When gramicidin S acts upon the intact cells of M. lysodeikticus, it impair with the permeability of their membranes and causes a loss of compounds absorbing at 260 nm; the derivatives with the substituted amino groups change the permeability of the cellular membranes only to a slight extent.

Adsorption↗
PubMedDate not supplied

[Formation of a resting form of Bacillus cereus and Micrococcus luteus].

Under certain cultivation conditions, the bacteria Bacillus cereus and Micrococcus luteus form cystlike refractive cells (up to 60% of the total number) that retain viability over a long time, are metabolically inactive and thermotolerant and possess specific ultrastructure. These properties allow them to be attributed to a new type of resting forms of microorganisms.

Aerobiosis↗
PubMed1976

[Isolation of cytochrome b556 from the membranes of Micrococcus lysodeikticus bacteria].

Proteins and cytochrome b556 were solubilized from Micrococcus lysodeikticus membranes using Triton X-100 treatment. Passing of this preparation through DEAE cellulose column in the presence of Triton X-100 made possible to isolate cytochrome b556 from other membrane cytochromes and to purify it up to the content of 2.3 nmol per mg of protein. The prostetic group of cytochrome b556 is determined to be protoheme for the spectrum of alkaline pyridinehemochrome.

Cytochromes↗
PubMed1976

Oxidative phosphorylation in Micrococcus denitrificans: calculation of the P/O ratio in growing cells.

P/O ratios were measured in membrane particles obtained from cells of Micrococcus denitrificans, while growing on different carbon sources. The membrane particles obtained from cells growing actively on glucose, succinate, ethanol and propanol as the carbon and energy sources catalyzed oxidative phosphorylation and yielded respective P/O ratios of 1.4, 1.2, 0.8, and 0.5 with NADH, and 0.8, 0.6, 0.6, and 0.5 with succinate as the electron donors. Not such a difference in P/O ratio is observed in intact resting cells grown with different carbon sources. It is concluded that the influence of the carbon source is probably directed towards the efficiency of oxidative phosphorylation in membrane particles and not in the growing cells. For the aerobic carbon source-limited chemostat cultures the following maximum growth yields were determined: 40.2 and 34.2 for succinate and oxygen, 41.7 and 36.5 for malate and oxygen, 81.4 and 39.4 for mannitol and oxygen, and 77.8 and 43.4 for gluconate and oxygen respectively. With a mathematical model (de Kwaadsteniet et al., in press) the P/O ratio was valued at 1.4-1.7. YATP at mu=0.2 was valued at 8.7-10.9; YmaxATP at 9.6-13.2 and me at 0.6-4.5 for the most precise experiment (gluconate-limited). The calculation of these growth parameters has been discussed.

Aerobiosis↗
PubMed1965

Purification and properties of erythro-beta-hydroxyasparate dehydratase from Micrococcus denitrificans.

1. The novel enzyme, erythro-beta-hydroxyaspartate dehydratase, a key enzyme of the beta-hydroxyaspartate pathway (Kornberg & Morris, 1963, 1965), has been purified 30-fold from extracts of glycollate-grown Micrococcus denitrificans. The purified preparation was devoid of erythro-beta-hydroxyaspartate-aldolase activity, and free from enzymes that act on oxaloacetate. 2. Properties of the purified dehydratase were studied by direct assay of the enzymic formation of oxaloacetate and ammonia from added erythro-beta-hydroxyaspartate. 3. The enzyme was highly substrate-specific, utilizing only the l-isomer of erythro-beta-hydroxyaspartate (K(m), 0.43mm, and V(max.), 99mumoles of oxaloacetate formed/min./mg. of protein at pH9.15 and 30 degrees ). Of many compounds tested, only maleate was a competitive inhibitor (K(i), 32mm at pH7.6). 4. The optimum pH for activity was about 9.5. The K(m) varied with pH, showing a marked optimum at pH7.8. The V(max.) also varied with pH in a manner suggesting the presence in the enzyme-substrate complex of a dissociable group of pK'(a) about 8.5. 5. Carbonyl reagents were inhibitory, but of three thiol reagents tested only p-chloromercuribenzoate was inhibitory. 6. A partially resolved preparation of the enzyme was activated four-fold by the addition of pyridoxal phosphate and thereby restored to half activity. 7. EDTA (0.1mm) was almost completely inhibitory, activity being restored by bivalent cations (Mg(2+), Ca(2+) and Mn(2+)); no activation by univalent cations was observed. 8. The findings are discussed in the light of reported properties of related hydroxyamino acid dehydratases.

Journal Article↗
PubMed1966

The deoxyribonucleic acid of Micrococcus radiodurans.

The DNA of Micrococcus radiodurans was prepared by three methods. Although the recovery of DNA varied considerably, the percentage molar base ratios of the DNA from the three preparations were essentially the same: guanine, 33+/-2; adenine, 18+/-1; cytosine, 33+/-2; thymine, 17+/-1. Base compositions calculated from T(m) values and from density in caesium chloride gradients also yielded guanine+cytosine contents of 66 and 68% of total bases respectively. No unusual bases were observed. The S(20,w) values were characteristic of high-molecular-weight DNA. Electron microscopy showed the purified DNA in long strands; occasionally these were coiled.

Journal Article↗
PubMed1973

The reactive serine residue in phosphoglucomutase of Micrococcus lysodeikiticus.

1. Phosphoglucomutase of Micrococcus lysodeikticus was labelled at the active site by exchange with (32)P-labelled substrates of high specific radioactivity. 2. Partial acid hydrolysis gave rise to radioactive peptides; serine phosphate was identified as one of the derivatives. 3. Comparison of the other (32)P-labelled peptides with the peptides obtained from the (32)P-labelled rabbit muscle phosphoglucomutase indicates that the sequence around the reactive serine residue is identical in both enzymes.

Autoradiography↗
PubMed1981

Increased transcription activity of rat liver chromatin after protein restriction and limited digestion of nuclei with micrococcus nuclease.

Protein restriction has been shown to produce either an enhancement or a reduction of transcription activity in vitro. Conditions for an enhanced transcription activity were investigated. Young male rats were fed a complete diet containing either 20% or 3% casein for 6 days. Body weight changed +7.4 g/day and -0.5 g/day, respectively. Liver wet weights were 6.8 and 3.7 g and the DNA amounts/g were 1.31 and 1.67 mg. Liver nuclei were incubated without or with 1 unit micrococcus nuclease (EC 3.1.4.7) per milligram of nuclear DNA, and chromatin was fractionated into a 2,000 x g, a 102,000 x g pellet and a supernatant fraction. In the livers of rats fed a low protein diet, chromatin-bound RNA polymerase I plus III and II activity/mg of fractional and nuclear DNA and soluble RNA polymerase activity were increased, while heparin-stimulated RNA polymerase II activity remained unchanged. An increased number of chains was synthesized by RNA polymerase I plus III without change in chain length and incorporation rate per chain. The length and incorporation rate per chain increased, while the number of chains synthesized by RNA polymerase II did not. After stimulation by heparin, an increased number of short chains was synthesized at a lower rate of incorporation per chain. In the complex chromating structures the capacity for RNA synthesis was determined by specific enzyme activity, RNA chain number and length.

Animals↗
PubMed1977

Purification and properties of an acid phosphatase of Micrococcus denitrificans distinct from thiamine phosphate phosphatase.

To determine whether the acid phosphatase in Micrococcus denitrificans participates in hydrolysis of thiamine phosphate in the synthesis of thiamine pyrophosphate, acid phosphatase was purified 280-fold by conventional procedures, which removed thiamine phosphate phosphatase completely. Studies showed that this acid phosphatase is a different protein from thiamine phosphate phosphatase and that it has no binding site for thiamine phosphate on its active site.

Acid Phosphatase↗
PubMed1976

The relevance of growth rates in urine to the pathogenesis of urinary-tract infections due to Micrococcus subgroup 3 (Staphylococcus saprophyticus biotype 3).

A novobiocin-resistant "biotype" of Micrococcus subgroup 3 (Staphylococcus saprophyticus) is known to be a primary pathogen of the female urinary tract and to cause infections as severe as those produced by Escherichia coli. The growth characteristics of this virulent biotype were compared in vitro with those of other Micrococcaceae and of E. coli to determine whether rapid growth explains the virulence of the biotype. Nutrient broth was shown to have growth-supporting qualities that differed from those of urine and it was therefore unsuitable for these studies. In urine, the virulent biotype grew more slowly, had a longer lag period, and reached much lower final viable counts than did Escherichia coli. Surprisingly, the virulent biotype also grew more slowly and reached a lower final viable count than did several other Micrococcaceae isolated from the urinary tract of healthy women. Urine from women who had suffered a recent infection with the virulent biotype had growth-supporting properties similar to those of urine from healthy women. Experiments with filtered forestream urine suggested that urethral secretions do not contain a factor determining growth rates of this organism in urine. The possibility that virulent strains adapt to rapid growth in urine was excluded. No evidence was obtained that the virulent biotype inhibits the growth of other Micrococcaceae in urine. Ability to grow rapidly in urine does not therefore explain the virulence of novobiocin-resistant strains of subgroup-3 micrococci.

Adult↗
PubMed1974

Effect of the systemic fungicide carboxin on electron transport function in membranes of Micrococcus denitrificans.

The systemic fungicide carboxin (5,6-dihydro-2-methyl-1,4-oxathiin-3-carboxanilide) inhibited oxidation of succinate by membranes prepared from Micrococcus denitrificans, the K(i) being 16 muM. Oxycarboxin (5,6-dihydro-2-methyl-1,4-oxathiin-3-carboxanilide-4,4-dioxide), F831 (5,6-dihydro-2-methyl-1,4-oxathiin-3-carboxanilide-4-oxide), and another succinate oxidase inhibitor, 4,4,4-trifluoro-1-(2-thienyl)-1,3-butanedione (TTB) were less effective inhibitors of succinate oxidation by membranes of M. denitrificans. Oxidation of other substrates (nicotinamide adenine dinucleotide, reduced form, d-lactate, l-lactate, malate, and d,l-alpha-hydroxybutyrate) was inhibited to a lesser degree by carboxin, and formate oxidation was entirely resistant. With all substrates tested, oxycarboxin, the dioxide analogue of carboxin, was less effective than carboxin. Carboxin also inhibited dichlorophenol indophenol (DCIP) reductase activities by these membranes in a manner both qualitatively and quantitatively similar to the inhibition of oxidation of the various substrates. The inhibition of DCIP reductase activities by TTB was qualitatively similar to carboxin, but TTB was a less effective inhibitor with all substrates tested. The inhibition of DCIP reductase by carboxin could be relieved by phenazine methosulfate with all substrates except d-lactate. Only slight inhibition of d-lactate-stimulated uptake of [(14)C]glycine by these membrane vesicles was seen with carboxin. Uptake of [(14)C]glycine could be stimulated to varying degrees with the other substrates tested, but in no case did carboxin cause significant inhibition. Membranes isolated from M. denitrificans are a useful system for investigating the mechanism of inhibition of electron transport function by carboxin, and the use of this system for evaluations of carboxin and its metabolites is suggested.

Carboxin↗
PubMed1979

Purification and Some Properties of an Extracellular Amylase from a Moderate Halophile, Micrococcus halobius.

A moderate halophile, Micrococcus halobius ATCC 21727, produced an extracellular dextrinogenic amylase when cultivated in media containing 1 to 3 M NaCl. The amylase was purified from the culture filtrate to an electrophoretically homogenous state by glycogen-complex formation, diethylaminoethyl-cellulose chromatography, and Bio-Gel P-200 gel filtration. The enzyme had maximal activity at pH 6 to 7 in 0.25 M NaCl or 0.75 M KCl at 50 to 55 degrees C. The activity was lost by dialysis against distilled water. Molecular weight was estimated to be 89,000 by sodium dodecyl sulfate-gel electrophoresis. The action pattern on amylose, soluble starch, and glycogen showed that the products were maltose, maltotriose, and maltotetraose, with lesser amount of glucose.

Journal Article↗
PubMed1980

Death of Micrococcus luteus in Soil.

Micrococcus luteus cells died relatively quickly when they were added to natural soil. The results were similar for soil in nature and as soil samples in the laboratory. The cells died more quickly when nutrients were added to the soil. Those cells that survived soil residence exhibited a temporary lengthening of the time required for colonial growth and pigment formation on laboratory media. They had not gained increased survival capability, however. This was evident when they were retested in soil. Good survival of the M. luteus cells was noted when the soil was incubated at lowered temperatures. Some protection to the cells was provided by slow drying of the soil during incubation or by addition of NaCl. Microscopic examination of the soil revealed that the M. luteus cells were being physically destroyed and that two different bacteria were growing in the areas where the cells had lysed. It was suggested that bacterial predators in the soil might be associated with the death of the M. luteus cells.

Journal Article↗