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DNA-DNA homology studies among strains of Arthrobacter and Brevibacterium.

Sixteen named strains of Arthrobacter and two strains of Brevibacterium were investigated by nucleic acid hybridisation. The Arthrobacter strains show homology values ranging between 11 and 55% to the type strain A. globiformis DSM 20124 (ATCC 8010), indicating only a low to moderate relationship. Two strains of A. globiformis, DSM 20124 and DSM 20125, exhibit only poor relationship to one another (30%). Among all the Arthrobacter strains the homology data range between 10 to 70% demonstrating separate status of almost all species. Only A. polychromogenes DSM 20136 was found to be a subspecies of A. oxydans DSM 20119. The type strain of A. citreus, DSM 20133 shows a remarkable lack of homology to four other strains of A. citreus, deposited as ATCC 15170, ATCC 17775, ATCC 21040 and ATCC 21348 (11--13%) which themselves can be separated into two groups according to the homology data (24--31%). Each of the two strains of Brevibacterium share high genetic relatedness with one of these A. citreus groups (71 and 73%, respectively). According to the DNA-DNA homology data, most of the species of Arthrobacter can actually be ranged taxonomically as species.

Arthrobacter

[Distribution of pyrimidine blocks in the DNA of Brevibacterium linens, Arthrobacter globiformis, Nocardia corallina and Nocardia rubra].

The nucleotide composition and the frequency of pyrimidine blocks were studied in DNA of the following bacteria: Brevibacterium linens (Weignamm, 1910) Breed, 1953; Arthrobacter globiformis (Conn, 1928) Conn et Dimmick, 1947; Nocardia corallina (Bergey et al., 1923) Waksman et Henrici, 1948; Nocardia rubra (Krassilnikov, 1949) Waksman et Henrici, 1948. These organisms are classed by some microbiologists as mycobacteria (the Mycobacteriaceae family) while other authors regard them as representatives of three families belonging to two orders. About 60 percent of all pyrimidines in DNA of these bacteria are found in the sequences pur-pyr-pur and pur-pyr-pyr-pur, the number of dipyrimidines being higher than the amount of monopyrimidine nucleotides. The content of dipyrimidine nucleotides in DNA of Nocardia corallina and Nocardia rubra is higher (16.8 mole %) than the content of dipyrimidine blocks in DNA of Brevibacterium linens and Arthrobacter globiformis, in which the quantity of dipyrimidines is almost the same (13.9 and 14.4 mole %). A new characteristic, the selected mean value, is suggested to evaluate differences in the distribution of pyrimidines in DNA.

Arthrobacter

Whole-genome analysis of Brevibacterium sanguinis AZMABM HM27: a bacterial isolate from the sea anemone Radianthus magnifica and exhibiting promising multi-therapeutic properties.

BACKGROUND: The marine anemone Radianthus magnifica harbors symbiotic microbes with promising biomedical potential, yet their diversity and therapeutic properties remain underexplored. This study aimed to characterize a symbiotic bacterium isolated from R. magnifica collected from Samalona Island, Indonesia, and to evaluate its multi-therapeutic potential. METHODS: Strain AZMABM HM27 was characterized using whole-genome sequencing, functional annotation, biosynthetic gene cluster prediction, molecular docking, and in vitro bioactivity assays. RESULTS: Phylogenetic and genome-based analyses confirmed AZMABM HM27 as Brevibacterium sanguinis, with an OrthoANI value of 97.37% and a dDDH value of 76.50% against the type strain. The genome comprises a 3,834,082 bp chromosome encoding 3,362 protein-coding genes, including 95 genes involved in secondary metabolite biosynthesis. Five biosynthetic gene clusters were predicted, including those associated with ectoine, terpene, and siderophore production. The crude extract demonstrated antioxidant activity (IC₅₀ = 0.87 mg/mL), anti-inflammatory activity (up to 60% inhibition), antidiabetic activity through α-glucosidase inhibition (up to 40% inhibition), and dose-dependent antiproliferative activity against MCF-7 breast cancer cells (74.10% viability at 1 mg/mL). Molecular docking identified a lead compound, 8,9,9,10,10,11-hexafluoro-4,4-dimethyl-3,5-dioxatetracyclo [5.4.1.0(2,6)0.0(8,11)] dodecane, with strong binding affinities to selected therapeutic targets. CONCLUSIONS: B. sanguinis AZMABM HM27 represents a marine symbiotic strain associated with R. magnifica and a promising source of bioactive compounds with antioxidant, anti-inflammatory, antidiabetic, and antiproliferative potential. Further purification, structural elucidation, and in vivo studies are warranted to validate its therapeutic potential.

Animals

Continuous production of NADP by immobilized Brevibacterium ammoniagenes cells.

Whole cells of Brevibacterium ammoniagenes IAM 1645 having the polyphosphate NAD-kinase were successfully immobilized in a polyacrylamide gel lattice. The immobilized cells were activated by treatment with organic solvents or detergents. The pH optimum of the immobilized cells for the production of NADP was 7.0, and divalent metal ions were required to maintain the elevated activity of polyphosphate NAD-kinase. Highly pure NADP was continuously produced in high yield by the immobilized cell column. The half-life of this column was about eight days.

Brevibacterium

Stereochemical studies of hydrogen incorporation from nucleotides with fatty acid synthetase from Brevibacterium ammoniagenes.

The biosynthesis of fatty acids from malonyl-CoA and acetyl-CoA was investigated with an enzyme preparation which was purified 100-fold from Brevibacterium ammoniagenes. Fatty acids synthesized in the presence of D2O and stereospecifically deuterated NADPH and NADH were isolated and analyzed by mass chromatography to examine the localization of deuterium in the molecule. The following results were obtained: 1) HB hydrogen of NADPH was used for beta-ketoacyl reductase. 2) HB hydrogen of NADH was used for enoyl reductase. 3) Hydrogen atoms from water were found on the even-numbered methylene carbon atoms (2-hydrogen atoms per carbon atom) and some were also found on the odd-numbered methylene carbon. 4) Hydrogen atoms from NADPH were found on odd-numbered methylene carbon atoms (1-hydrogen per carbon). 5) Hydrogen atoms from NADH were also found on the odd-numbered methylene carbon atoms, but the number of incorporated hydrogen atoms was less than expected. The exchange of HB hydrogen of NADH with water catalyzed by enoyl reductase was suspected. 6) The exchange of methylene hydrogen atoms of malonyl-CoA with proton of water was suggested by 13C NMR analysis.

Brevibacterium

Aminopeptidase from Brevibacterium linens: activation and inhibition.

Activation and inhibition of a purified aminopeptidase from Brevibacterium linens was investigated using L-alpha-leucyl-4-nitroanilide and L-leucyl-L-leucine as substrates. The enzyme was activated by cobalt, provided that the enzyme was preincubated with the metal. Strong inhibitory effects were derived from heavy metals, metal-complexing compounds, reducing agents, the modification of aromatic amino acids, and the presence of hydrophobic substances or certain amino acids in the test mixtures. Supposing that this B. linens aminopeptidase plays a part during surface-ripening of cheeses, possible consequences of specific technological conditions for its activity are discussed.

Amino Acids

Glycolipids of brevibacterium vitarumen.

Corynomycolic acids have been identified in the lipids of Brevibacterium vitarumen. The analogy between this strain and typical aerobic Corynebacteria is borne out by these complex lipids, corynomycolic acid being linked as 6,6'-dicorynomycoloyl-trehalose (cord-factor structure) and as 6-monocorynomycoloyl-trehalose.

Brevibacterium

Isolation procedure and properties of monomer unit from lysozyme digest of peptidoglycan complex excreted into the medium by penicillin-treated Brevibacterium divaricatum mutant.

1. The peptidoglycan complex excreted in large amounts into the medium by the biotin-requiring mutant Brevibacterium divaricatum NRRL-2311 incubated in the presence of penicillin for 1 h has been investigated. A convenient isolation procedure with high yield for the pure monomeric unit from lysozyme digest of the accumulated polymer is described. 2. It is shown that the released peptidoglycan possesses the linear uncross-linked structure made of repeating disaccharide-pentapeptide unit [GlcNAc-MurNac-Ala-D-Glyn(meso-DAP-D-Ala-D-Ala)] which was isolated by stepwise gel filtration and fractionation of the digestion mixture in 10-mg quantities. Evidence that the minor digestion product of accumulated peptidoglycan possesses the glycan-linked dimer structure is given. Under conditions of beta-elimination, the monomeric unit yielded a lactylpentapeptide which was isolated in pure form by gel filtration. 3. The monomer unit originating from the cultures to which L-[U-14C]glutamic acid was added simultaneously with penicillin incorporated the label exclusively in the peptide chain, whereas that labeled from E11-14C]acetate as the precursor contained radioactivity in both the peptide chain (53%) and N-acetylamino groups (47%) of the glycan portion.

Amino Acids

Oxidation of 3beta-hydroxyandrostenes by the 3beta-hydroxy-steroid oxidase (cholesterol oxidase) from Brevibacterium sterolicum prior to their analysis by gas-liquid chromatography-mass spectrometry.

The 3beta-hydroxysteroid oxidase from Brevibacterium sterolicum has been applied to the oxidation of a number of 3beta-hydroxyandrostenes, including polar steroids containing up to three other hydroxylic groups. The substrates, products, and derivatives thereof have been examined by gas-liquid chromatography. Retention index increments for these conversions, and for parallel transformations of other steroids, show considerable regularities, and together with mass spectrometric data afford characteristic structural information.

3-Hydroxysteroid Dehydrogenases

Fatty acid synthetase from Brevibacterium ammoniagenes: formation of monounsaturated fatty acids by a multienzyme complex.

A multienzyme fatty acid synthetase complex isolated from Brevibacterium ammoniagenes has been purified to a specific activity of 1440 nmol of malonyl-CoA incorporated per min/mg. The enzyme is homogeneous, as judged by gel electrophoresis on agarose gels, and has a molecular weight of 1.2 X 10(6). Both NADPH and NADH are required for activity. In contrast to other fatty acid synthetase complexes, the enzyme catalyzes the synthesis of both long-chain saturated and monounsaturated fatty acids from malonyl-CoA and acetyl-CoA. The formation of unsaturated fatty acids is oxygen-independent and sharply reduced by 3-decynoyl-N-acetylcysteamine, a known inhibitor of Escherchia coli beta-hydroxydecanoyl thioester dehydrase (EC 4.2.1.60).

Aerobiosis

Altered prephenate dehydratase in phenylalanine-excreting mutants of Brevibacterium flavum.

The regulatory properties of three key enzymes in the phenylalanine biosynthetic pathway, 3-deoxy-D-arabino-heptulosonate 7-phosphate synthetase (DAHP synthetase) [EC 4.1.2.15], chorismate mutase [EC 5.4.99.5], and prephenate dehydratase [prephenate hydro-lyase (decarboxylating), EC 4.2.1.51] were compared in three phenylalanine-excreting mutants and the wild strain of Brevibacterium flavum. Regulation of DAHP synthetase by phenylalanine and tyrosine in these mutants did not change at all, but the specific activities of the mutant cell extracts increased 1.3- to 2.8-fold, as reported previously (1). Chorismate mutase activities in both the wild and the mutant strains were cumulatively inhibited by phenylalanine and tyrosine and recovered with tryptophan, while the specific activities of the mutants increased 1.3- to 2.8-fold, like those of DAHP synthetase. On the other hand, the specific activities of prephenate dehydratase in the mutant and wild strains were similar, when tyrosine was present. While prephenate dehydratase of the wild strain was inhibited by phenylalanine, tryptophan, and several phenylalanine analogues, the mutant enzymes were not inhibited at all but were activated by these effectors. Tyrosine activated the mutant enzymes much more strongly than the wild-type enzyme: in mutant 221-43, 1 mM tyrosine caused 28-fold activation. Km and the activation constant for tyrosine were slightly altered to a half and 6-fold compared with the wild-type enzyme, respectively, while the activation constants for phenylalanine and tryptophan were 500-fold higher than the respective inhibition constants of the wild-type enzyme. The molecular weight of the mutant enzyme was estimated to be 1.2 x 10(5), a half of that of the wild-type enzyme. The molecular weight of the mutant enzyme was estimated to be 1.2 X 10(5) a half of that of the wild type enzyme, while in the presence of tyrosine, phenylalanine, or tryptophan, it increased to that of the wild-type enzyme. Immediately after the mutant enzyme had been activated by tyrosine and then the tyrosine removed, it still showed about 10-fold higher specific activity than before the activation by tyrosine. However, on standing in ice the activity gradually fell to the initial level before the activation by tyrosine. Ammonium sulfate promoted the decrease of the activity. On the basis of these results, regulatory mechanisms for phenylalanine biosynthesis in vivo as well as mechanisms for the phenylalanine overproduction in the mutants are discussed.

3-Deoxy-7-Phosphoheptulonate Synthase

Stereochemical studies of hydrogen incorporation from nucleotides with fatty acid synthetase from Brevibacterium ammoniagenes.

The biosynthesis of fatty acids from malonyl-CoA and acetyl-CoA was investigated with an enzyme preparation which was purified 100-fold from Brevibacterium ammoniagenes. Fatty acids synthesized in the presence of D2O and stereospecifically deuterated NADPH and NADH were isolated and analyzed by mass chromatography to examine the localization of deuterium in the molecule. The following results were obtained: 1) HB hydrogen of NADPH was used for beta-ketoacyl reductase. 2) HB hydrogen of NADH was used for enoyl reductase. 3) Hydrogen atoms from water were found on the even-numbered methylene carbon atoms (2-hydrogen atoms per carbon atom) and some were also found on the odd-numbered methylene carbon atoms. 4) Hydrogen atoms from NADPH was found on the odd-numbered methylene carbon atoms (1 hydrogen per carbon). 5) Hydrogen atoms from NADH was also found on the odd-numbered methylene carbon atoms, but the number of incorporated hydrogen atoms was less than expected. The exchange of HB hydrogen of NADH with water catalyzed by enoyl reductase was suspected. 6) The exchange of methylene hydrogen atoms of malonyl-CoA with protons of water was suggested by 13C NMR analysis.

Acetyl Coenzyme A

Enzymes of the glutamate and aspartate synthetic pathways in a glutamate-producing bacterium, Brevibacterium flavum.

Glutamate-auxotrophic mutants lacking phosphoenolpyruvate carboxylase(PC), citrate synthase (CS) or glutamate dehydrogenase (GD), an aspartate auxotroph lacking aspartate aminotransferase (TA), and a glutamate-aspartate double auxotroph lacking both aconitase (AH) and TA were obtained from Brevibacterium flavum No. 2247, a glutamate-producing bacterium. Prototrophic revertants further derived from the CS- and GD-lacking auxotrophs concomitantly recovered the enzyme activities that their parents had lost. These results indicate involvement of the tricarboxylic acid (TCA) cycle and GD in glutamate biosynthesis, that of PC in the biosynthesis of the TCA cycle intermediates and that of TA in aspartate biosynthesis. The CS-deficient mutants accumulated large amounts of acetate and small amounts of pyruvate, aspartate and alanine, while the GD-deficient strains accumulated large amounts of 2-oxo-glutarate and small amounts of citrate. Synthesis of PC was repressed by either glutamate or aspartate and those of CS and GD were repressed by glutamate, whereas those of pyruvate dehydrogenase (PD), AH, and isocitrate dehydrogenase were not affected significantly by glutamate; that of TA was also not affected by aspartate or by glutamate. The specific activities of PD and AH gave peaks during the cellular cultivation, related to the temporary accumulation of their substrates, pyruvate and citrate, respectively. These and previous results on the regulation of the enzymatic activities provide a definite regulatory mechanism for glutamate and aspartate syntheses.

Aconitate Hydratase

Brevibacterium liquefaciens adenylate cyclase and its in vivo stimulation by pyruvate.

Adenylate cyclase of Brevibacterium liquefaciens depends on pyruvate for activity. Growing in a simple medium containing glucose and DL-alanine, the microorganism excreted pyruvate, which reached 20 mM in the medium at stationary phase. Using [3H]adenosine to label the adenosine 5'-triphosphate pool, we showed that pyruvate in the medium stimulated adenylate cyclase of B. liquefaciens in vivo, in a manner similar to the stimulation observed in vitro. Adenylate cyclase in cells harvested at different phases of growth was equally responsive to exogenous pyruvate, indicating that the allosteric site for pyruvate was present in the enzyme throughout the various phases of cell growth. The specific activity of adenylate cyclase was highest in cells harvested at early log phase; thereafter it declined and was substantially lower at stationary phase. Although adenylate cyclase appears to be activated by pyruvate throughout the life span of the cell, the activity appears not to be critical to cell growth, which was comparable whether the medium contained high or low pyruvate.

Adenosine

[Spectrum of amidase activity in a mutant of Brevibacterium].

Brevibacterium R 312 has a fairly non-specific amidase. Following the loss of this enzyme by mutation, the following enzymatic activities could be demonstrated: hydrolysis of urea, formamide, nicotinamide, L-glutamine, glycinamide and L-alpha-amino amids.

Amidohydrolases

[Alternative oxidation pathways in the respiratory chain of Brevibacterium flavum].

A scheme is proposed for the branched respiratory chain in Brevibacterium flavum 22 LD. Three branching sites in the main electron transport pathway are suggested: at the initial stage of NADH2 oxidation (before menaquinone) and at the levels of cytochromes b and c. Up to 40% out of the total oxygen is consumed in the NADH2-dependent alternative oxidative pathway in the presence of 5.10(-3) M cyanide or after the near UV treatment. This bypass differs from the main electron flow with a lower P/O ratio. Exogenous NADH2 catalyses the univalent reduction of oxygen through superoxide production in the bacterial membranes. Alternative oxidation pathways are discussed regarding their regulatory role in the bacterial energy metabolism.

Brevibacterium

[Nucleases from Brevibacterium ammoniagenes differing in their effects on chromatin].

A method of isolation of three different, partially purified deoxyribonucleases from the cells of Brevibacterium ammoniagenes is descrirbed. The enzyme preparations were activated by various bivalent metal ions: 50mM MgCl2 (I), 5 mM CaCl2+5 mM MgCl2 (II), 10 mM CaCl2 (III), and had different pH optima -- 8.8 (I), 7.2 (II) and 8.2 (III). In the isolated nuclei of rat brain the first and third fractions split chromatin at the internucleosomal sites with a formation of nucleosomes -- structural subunits of chromatin. The second fraction exhibited no structural specificity for chromatin. A possible use of the enzymes for the analysis of chromatin structure is discussed.

Brevibacterium