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At least 73 records · Page 4Linked to original sources
PubMed1977

Inhibition of diptheroid esterase by Micrococcus luteus.

Micrococcus luteus produced a diffusible, esterase inhibitory factor (EIF) which inhibited the activity of cutaneous diphtheroid esterases on Tween 80-CaCl2 agar media. Esterases of Staphylococcus, Micrococcus, Bacillus, and Serratia were not susceptible. EIF did not appear to combine with the substrate or to prevent enzyme synthesis; it was unable to reverse the precipitation of calcium oleate. The composition of the medium, especially peptones, influenced the production of EIF. EIF was synthesized in the absence of diphtheroids, but production required the presence of Tween. The interaction was observed on agar medium of pH 5.5-8.5, at 25-43 degrees C, under an atmosphere of 10-20% CO2, in the presence of urea, but not after the addition of NaCl or dextrose. Supernatants of broth cultures had to be concentrated to detect EIF. Crude dialyzed and concentrated preparations of EIF withstood 60 degrees C for 60 min but were inactivated after 100 degrees C for 10 min. EIF may possibly be associated with a lipoid substance, since it did not precipitate in ethanol.

Bacillus↗
PubMed1978

Flocculation and adsorption of enzymes during growth of a moderate halophile, Micrococcus varians var. Halophilus.

Flocculation of a moderate halophile, Micrococcus varians ATCC 2197, occurred during growth in complex medium containing 3 M NaCl and a concentration of MgSO4 and KH2PO4 greater than 40 and 14 mM, respectively. Extracellular nuclease activity was absent in the flocculated cultures. Repeated washing of flocs by Mg2+-free Tris buffer containing 3 M NaCl, lowering of pH value of floc suspension below 6.3, or addition of ethylenediaminetetraacetic acid resulted in complete dissociation of the flocs and release of Mg2+ ions as well as nuclease and amylase. Inhibition of extracellular enzyme production accompanied by flocculation appeared to be the result of adsorption of enzyme proteins to surfaces of the flocs, but not of inhibition of biosynthesis. Floc formation could also occur in media containing 18 mM CaCl2 and 3.0 mM KH2PO4, but the Ca flocs were not deflocculated by washing with Ca2+-free buffer, suggesting that the affinity of Ca2+ for cell envelopes was stronger than that of Mg2+. It was also observed that most halophilic Planococcus and Micrococcus flocculated in the presence of MgSO4 and phosphate but halophilic Pseudomonas, Acinetobacter, and Bacillus did not.

Adsorption↗
PubMed1975

Purification and some properties of the soluble and membrane-bound adenosine deaminases of Micrococcus sodonensis ATCC 11880 and their distribution within the family Micrococcacea.

In Micrococcus sodonensis and some other Micrococcus species, adenosien deaminase is present both as a membran-bound and a soluble enzyme; The membran-bound adenosine deaminase can be extracted with n-butanol, and may account for up to 5% of the total cellular adenosine deaminase activity. In a number oc comparative tests, no differences between the two enzyme forms could be found, thus they are believed to be similar molecular species; The purified membran-bound or soluble enzyme had a molecular weight, obtained by gel-filtration, of 130 000 and was inactive toward adenine and adenine mononucleotides. It appears, therefore, to be more closely related to the calf-intestine enzyme than the Aspergillus oryzae form in respect to size and substrate specificity; Attempts to correlate membrane-bound adenosine deaminase activity with adenosine transport in isolated membrane vesicles of M. sodonensis indicated no obvious relationship between the two activities.

Adenosine↗
PubMed1993

Intracranial suppuration caused by Micrococcus luteus.

Micrococcus spp. are commensal organisms colonizing the body surfaces of humans. In a few instances these organisms have been reported to colonize ventricular shunts. We report a patient, with no overt evidence of immunosuppression, in whom Micrococcus luteus was responsible for intracranial suppuration at multiple sites.

Adult↗
PubMed1992

Pneumonia due to Micrococcus spp. in a patient with acute myeloid leukaemia.

A 26-year-old female patient with acute myeloid leukaemia was hospitalized for the second cycle of remission induction chemotherapy. While neutropenic she developed progressive pulmonary infiltrate, with Micrococcus spp. cultured from two consecutive bronchoalveolar lavage fluids, resulting in respiratory insufficiency. The patient died after an unsuccessful cardiopulmonary resuscitation. This report of micrococcal pneumonia emphasizes that the pathogenicity of this skin commensal is not limited to infections in tissues surrounding prosthetic devices or indwelling intravenous catheters. Especially in immunocompromised patients, Micrococcus spp. from bronchoalveolar lavage fluids cannot be lightly dismissed as non-pathogenic when pneumonia is considered.

Adult↗
PubMed1983

[Isolation from Micrococcus sp. n. of a homogeneous heme-containing catalase and a crystalline protein with catalase activity].

A method for isolation and purification of catalases from the culture of Micrococcus sp. n. grown under aeration conditions is described. Heme-containing catalase (I) and the protein possessing a catalase activity (II) were separated by fractionation with ammonium sulfate. The specific activity of the highly purified protein causing degradation of H2O2 is 200 times less than that of the heme-containing enzyme. The molecular weights of catalases I and II as determined by electrophoresis in polyacrylamide gel gradient 4/30% are 240000 and 130000, respectively. The method described is designed at rapid isolation of preparative amounts of catalases from Micrococcus sp. n.

Catalase↗
PubMed1977

Restriction of the anti-bovine serum albumin response in rabbits immunized with Micrococcus lysodeikticus.

Rabbits capable of producing antibodies of restricted heterogeneity in response to Micrococcus lysodeikticus are equally capable of producing antibodies of restricted heterogeneity to bovine serum albumin. These antibodies are produced when animals are simultaneously injected with micrococcus and BSA and their specificity is restricted to a small number of epitopes. These results suggest that micrococcal vaccines can induce the restriction of heterogeneity in antibodies raised against totally unrelated antigens.

Animals↗
PubMed1994

A water-soluble fragment of Micrococcus lysodeikticus cell wall.

A fragment of Micrococcus lysodeikticus cell wall was obtained by extraction of walls with water, dimethylformamide or dimethyl sulfoxide. The water-soluble polymer was obtained from the cell walls prepared either with or without trypsin treatment of the cell. This fragment was studied by the Smith periodate oxidation, methylation, mild acid treatment and enzymic procedures. The polymer consists of polysaccharide chains composed of (1-->4)-O-(2-acetamido-2-deoxy-beta-D-mannopyranosyluronic acid)-(1-->6)-O-alpha-D-glucopyranosyl residues. The polysaccharide chain is linked to C-6 of a 2-acetamido-3-O-(D-1-carboxyethyl)-2-deoxy-beta-D-gluco-pyranosyl residue of a peptidoglycan chain composed of repeating (1-->4)-O-(2-acetamido-2-deoxy-beta-D-glucopyranosyl)-(1-->4)-[2-acet ami do-3-O-(D-1-carboxyethyl)-2-deoxy-beta-D-glucopyranosyl] residues. The water-soluble cell-wall fragment was also observed in the-culture medium of Micrococcus lysodeikticus and was also extractable from the cells in minor quantity.

Carbohydrate Sequence↗
PubMed1991

Influence of repeated lyophilization on the survival of Deinococcus proteolyticus, Micrococcus luteus and Escherichia coli.

Repeated lyophilization of Deinococcus proteolyticus, Micrococcus luteus and Escherichia coli cells results in a successive decrease of their survival. The survival curve is exponential with E. coli and M. luteus, and sigmoidal with a broad shoulder with D. proteolyticus both after repeated lyophilization and after UV- or gamma-irradiation. When cells were subjected to gamma-irradiation after a 20-fold freeze-drying, the corresponding survival curve became exponential without the shoulder. Hence we assume that irradiation and repeated lyophilization afflict the same cellular structures and/or functions.

DNA, Bacterial↗
PubMed2025

Characterization of Micrococcus luteus Lipidome Containing Novel Lipid Families by Multiple Stage Linear Ion-Trap with High Resolution Mass Spectrometry.

Micrococcus luteus (M. luteus) is a ubiquitous, long-existing Gram-positive bacterium with a distinctive yellow or golden color. It is a model organism for laboratory studies due to its small genome and ease of cultivation. However, only limited knowledge about its constituent lipid structure is known, and its entire lipid profile remains unclear. Here, we applied linear ion trap (LIT) multiple-stage mass spectrometry (MSn) with high resolution for structural characterization of the native lipid extract, along with GC/MS analysis of the acid hydrolysate to reveal the structural details of the entire lipidome, which includes the major phosphatidylglycerol (PG), cardiolipin (CL), phosphatidylinositol (PI), dimannosyl diacylglycerol (DMDG), and minor diacylglycerol (DAG) lipid families. Importantly, we also found two extra lipid families, the new phosphatidyl 1,3-propanediol and the known polyprenyl 1-phosphosate that was not previously reported for M. luteus. We also revealed the unique lipidome simplified by the dominance of branched 15:0-fatty acid substituents (>90% branched 15:0-FA with anteiso-15:0 to iso-15:0 abundance ratio of 4/1), which is in line with the small genome of M. luteus. In addition, the applied LIT MSn mass spectrometry revealed a fragmentation pathway that undergoes internal loss of a glycerol residue specific to DMDG, leading to its structural characterization.

Micrococcus luteus↗
PubMed1977

The enzymatic conversion of L-histidine to urocanic acid by whole cells of Micrococcus luteus immobilized on carbodiimide activated carboxymethylcellulose.

Whole cells of Micrococcus luteus (formerly Sarcina lutea ATCC 9341) have been covalently linked to a carboxymethylcellulose support system, with the retention of histidine ammonia-lyase activity. The dependence of the rate of urocanic acid formation on pH, temperature, and added surfactant concentration was similar for the free and the immobilized cells. The immobilization procedure used is based on the carbodiimide activation of carboxymethylcellulose and has been optimized for the histidine ammonia-lyase activity of the immobilized cells on a given weight of cellulose. In a column reactor at 23 degrees C and superficial velocity of 0.044 cm/min, 5 g of cellulose with bound cells gave a 35% conversion of an L-histidine solution (0.25M, pH 9.0) to urocanic acid for 16 days of continuous operation. The scope of this carbodiimide assisted immobilization procedure has been investigated for a series of microorganisms and a variety of carboxylate functionalized supports.

Ammonia-Lyases↗
PubMed1983

The immunomodulatory effect of anti-Micrococcus luteus antibodies. I. Effect on in vitro rabbit T cell functions.

A range of purified rabbit anti-Micrococcus luteus antibodies (anti-MCAb) were tested for their ability to interfere with a variety of in vitro immune responses. Such antibodies strongly inhibited the secondary IgG antibody response to sheep red blood cells without affecting the IgM response or the proliferative responses to mitogens and antigens. By exposing lymphocyte populations to anti-MCAb, it was found that such reagents exerted a strong mitogenic effect on rabbit T lymphocytes, provided these cells were derived from antigen-activated lymph nodes. This mitogenic effect was also obtained with F(ab')2 fragments of anti-MCAb and with hybridoma-derived anti-MCAb. Collectively, these data indicate that anti-MCAb inhibit the initiation of IgG synthesis possibly through the expansion of immunoregulatory T cell subsets.

Animals↗
PubMed1979

Micrococcus luteus pneumonia: a case report and review of the literature.

The clinical course of a 69-year-old male with acute myelogenous leukemia is described who, while extremely leukopenic (less than 100 neutrophils/microliter) from chemotherapy, developed a cavitating pneumonia due to a gram-positive coccus, Micrococcus luteus. Aggressive antibiotic management and attainment of complete remission of his leukemia resulted in a successful outcome. A review of the literature regarding the pathogenicity of this organism and, in particular, its occurrence as a cause of pneumonia is presented.

Aged↗
PubMed1993

Unassigned or nonsense codons in Micrococcus luteus.

We previously reported that in Micrococcus luteus, a Gram-positive eubacterium with high genomic G + C content, certain codons ending with A did not appear in coding frames, including termination sites, and tRNAs that translate these codons were not detected. These facts suggest that at least some of them are unassigned (nonsense) codons, i.e. not assigned to any amino acid or to any stop signal. We have investigated whether AGA and AUA, universal Arg and Ile codons, respectively, are really unassigned codons by using a cell-free extract prepared from M. luteus and synthetic messenger RNAs. Translation of synthetic mRNA containing in-frame AGA codons does not result in "read-through" to codons beyond the AGA codons, i.e. translation ceases at codon AGA. Essentially the same result was obtained with mRNA containing AUA in-frame. A sucrose-gradient centrifugation profile of the reaction mixture has shown that practically all of the peptides that have been synthesized are attached to 70 S ribosomes. When in-frame AGA or AUA codons are replaced by UGA codons in mRNA, no read-through occurs beyond UGA, just as in the case of AGA or AUA. However, the synthesized peptide is released from the 70 S ribosomes. These data suggest that AGA and AUA are unassigned codons and differ from UGA in that they are not used for termination.

Adenine Nucleotides↗
PubMed1994

Analysis of a complex plasmid insertion in a phototaxis-deficient transformant of Dictyostelium discoideum selected on a Micrococcus luteus lawn.

A novel method for clonal selection of G418-resistant Dictyostelium discoideum transformants on lawns of Micrococcus luteus was developed. The procedure was used to isolate transformants deficient in phototaxis after nontargeted insertion of shuttle vector DNA. Southern blot analysis as well as restriction, T-tracking, and sequencing analysis of plasmids rescued from the genomic DNA of one of the putative phototaxis gene disruptants showed that it contained a complex multicopy insertion of the vector. While insertions of such plasmid vectors might typically be in tandem multicopy format, they can be much more complex, containing, as in this case, inverse as well as tandemly duplicated copies and various deletions.

Animals↗
PubMed1975

Substrate specificity of Micrococcus luteus UV endonuclease and its overlap with DNA photolyase activity.

The action of an endonuclease from Micrococcus luteus that operates on UV damage in DNA overlaps with that of DNA photolyase from yeast: homo- and heterocyclobutane dipyrimidines in DNA are substrates for both enzymes, but pyrimidine adducts or the "spore photoproduct" in DNA are not. As expected from this overlap, the action of the two enzymes is mutually interfering: single-strand nicks introduced by the endonuclease effectively preclude photoreactivation; conversely, formation of a photolyase-cyclobutane dipyrimidine complex can prevent nicking by the endonuclease.

Base Sequence↗
PubMed1975

Repair of double-strand breaks in Micrococcus radiodurans.

Micrococcus radiodurans has been shown to sustain double-strand breaks in its DNA after exposure to X-radiation. Following sublethal doses of X-rays (200 krad in oxygen or less), the cells were able to repair these breaks, and an intermediate fast-sedimenting DNA component seemed to be involved in the repair process.

Cell Membrane↗