New polyenic antibiotics active against gram-positive and gram-negative bacteria. VIII. Construction of synthetic medium for production of mono-chloro-congeners of enacyloxins. (25/68)

New antibiotics enacyloxins (ENXs) are a family of non-lactonic polyene antibiotics produced by Frateuria sp. W-315. For the production of antibiotics, we had to employ two-step fermentations, the first is the production of spent medium of Neurospora crassa and the second is the production of antibiotics by Frateuria. To simplify the production of antibiotics, systematic analyses have been done on the spent medium, and factors which affect the production of antibiotics characterized. From the above results, we constructed a new medium for antibiotic production. Moreover, we could get a new antibiotic named enacyloxin IIIa (1), C33H48O11NCl (m/z 669). 1 was deduced to be one of the congeners of enacyloxins because it was similar to ENX IIa or ENX IVa both in biological and physico-chemical properties. Chlorine of 1 could be replaced by bromine, biosynthetically, and the resultant bromine-containing antibiotic also showed an antibacterial activity comparable to 1.  (+info)

Saccharibacter floricola gen. nov., sp. nov., a novel osmophilic acetic acid bacterium isolated from pollen. (26/68)

Three Gram-negative, aerobic, rod-shaped bacterial strains were isolated, from the pollen of Japanese flowers, as producers of xylitol; these strains were subjected to a polyphasic taxonomic study. Phylogenetic analyses of the 16S rRNA gene sequences demonstrated that these three isolates formed a new cluster within a group of acetic acid bacteria in the alpha-Proteobacteria. The characteristics of the three isolates were as follows: (i) their predominant quinone was Q-10; (ii) their cellular fatty acid profile contained major amounts of 2-hydroxy acids and an unsaturated straight-chain acid (C(18 : 1)omega7c); and (iii) their DNA G+C contents were in the range 51.9-52.3 mol%, which is around the lower limit of the reported range for the genera of acetic acid bacteria. The negligible or very weak productivity of acetic acid from ethanol and the osmophilic growth properties distinguished these strains from other acetic acid bacteria. The unique phylogenetic and phenotypic characteristics suggest that the three isolates should be classified within a novel genus and species with the proposed name Saccharibacter floricola gen. nov., sp. nov. The type strain is strain S-877(T) (=AJ 13480(T)=JCM 12116(T)=DSM 15669(T)).  (+info)

Enzymatic reduction of benzoyl-CoA to alicyclic compounds, a key reaction in anaerobic aromatic metabolism. (27/68)

Different anaerobic bacteria can oxidize a variety of aromatic compounds completely to CO2 via one common aromatic intermediate, benzoyl-CoA. It has been postulated that anaerobically the aromatic nucleus of benzoyl-CoA becomes reduced. An oxygen-sensitive enzyme system is described catalyzing the reduction of benzoyl-CoA to trans-2-hydroxycyclohexanecarboxyl-CoA in a denitrifying Pseudomonas species grown anaerobically on benzoate plus nitrate. The assay mixture consists of cell extract, [U-14C]benzoyl-CoA, a [U-14C]benzoyl-CoA-generating system (consisting of [U-14C]benzoate, purified benzoate-CoA ligase, Mg(2+)-ATP, coenzyme A), an ATP-regenerating system (consisting of phosphoenolpyruvate, pyruvate kinase, myokinase), and a low-potential reductant [titanium(III) citrate]. The optimal pH is about 7, the specific activity 10 nmol benzoyl-CoA reduced min-1 x mg-1 protein. The apparent Km for benzoyl-CoA is below 50 microM. Five major products were found. One product is cyclohex-1-enecarboxyl-CoA which must have been formed by a benzoyl-CoA reductase. The other product is probably trans-2-hydroxycyclohexanecarboxyl-CoA rather than the cis-stereoisomer; this product must have been formed by a cyclohex-1-enecarboxyl-CoA hydratase. Two other products are likely to be intermediates of benzoyl-CoA reduction to cyclohex-1-enecarboxyl-CoA, suggesting that the reduction reaction is more complex. An early formed fifth product is more polar than cyclohexanecarboxyl- or cyclohex-1-enecarboxyl-CoA. The enzyme system is under oxygen control since it was not found in cells grown aerobically on benzoate. It is induced by aromatic compounds since its activity is low in cells grown anaerobically on acetate. The actual inducer is probably benzoyl-CoA rather than benzoate. This conclusion is drawn from the fact that the system is also present in cells grown anaerobically on phenol, phenylacetate, 4-hydroxybenzoate, or 2-aminobenzoate; the anaerobic metabolism of these compounds has been shown in this organism to proceed directly via benzoyl-CoA rather than via free benzoate.  (+info)

New polyenic antibiotics active against gram-positive and gram-negative bacteria. IV. Structural elucidation of enacyloxin IIa. (28/68)

The chemical structure of a unique polyenic antibiotic enacyloxin IIa (former name: fr. 2) produced by Frateuria (formerly Gluconobacter) sp. W-315 has been determined by extensive spectroscopic studies, in particular by NMR spectral analysis. It has a novel non-lactonic structure involving 3,4-dihydroxycyclohexanecarboxylic acid with a chlorine-containing polyenic and polyhydroxy acyl side chain attached as an ester to the 3-hydroxyl substituent of the acid.  (+info)

Neoasaia chiangmaiensis gen. nov., sp. nov., a novel osmotolerant acetic acid bacterium in the alpha-Proteobacteria. (29/68)

An acetic acid bacterium, designated as isolate AC28(T), was isolated from a flower of red ginger (khing daeng in Thai; Alpinia purpurata) collected in Chiang Mai, Thailand, at pH 3.5 by use of a glucose/ethanol/acetic acid (0.3%, w/v) medium. A phylogenetic tree based on 16S rRNA gene sequences for 1,376 bases showed that isolate AC28(T) constituted a cluster along with the type strain of Kozakia baliensis. However, the isolate formed an independent cluster in a phylogenetic tree based on 16S-23S rDNA internal transcribed spacer (ITS) region sequences for 586 bases. Pair-wise sequence similarities of the isolate in 16S rRNA gene sequences for 1,457 bases were 93.0-88.3% to the type strains of Asaia, Kozakia, Swaminathania, Acetobacter, Gluconobacter, Gluconacetobacter, Acidomonas, and Saccharibacter species. Restriction analysis of 16S-23S rDNA ITS regions discriminated isolate AC28(T) from the type strains of Asaia and Kozakia species. Cells were non-motile. Colonies were pink, shiny, and smooth. The isolate produced acetic acid from ethanol. Oxidation of acetate and lactate was negative. The isolate grew on glutamate agar and mannitol agar. Growth was positive on 30% D-glucose (w/v) and in the presence of 0.35% acetic acid (w/v), but not in the presence of 1.0% KNO(3) (w/v). Ammoniac nitrogen was hardly assimilated on a glucose medium or a mannitol medium. Production of dihydroxyacetone from glycerol was weakly positive. The isolate did not produce a levan-like polysaccharide on a sucrose medium. Major isoprenoid quinone was Q-10. DNA base composition was 63.1 mol% G+C. On the basis of the results obtained, Neoasaia gen. nov. was proposed with Neoasaia chiangmaiensis sp. nov. The type strain was isolate AC28(T) (=BCC 15763(T) =NBRC 101099(T)).  (+info)

First report of bacteremia by Asaia bogorensis, in a patient with a history of intravenous-drug abuse. (30/68)

We report the first documented case of bacteremia caused by Asaia bogorensis in a young patient with a history of intravenous-drug abuse. A. bogorensis was identified by sequencing the 16S rRNA gene. The isolate was exceptionally resistant to almost all antibiotics that are routinely tested for gram-negative rods but was susceptible to netilmicin, gentamicin, and doxycycline.  (+info)

High shikimate production from quinate with two enzymatic systems of acetic acid bacteria. (31/68)

3-Dehydroshikimate was formed with a yield of 57-77% from quinate via 3-dehydroquinate by two successive enzyme reactions, quinoprotein quinate dehydrogenase (QDH) and 3-dehydroquinate dehydratase, in the cytoplasmic membranes of acetic acid bacteria. 3-Dehydroshikimate was then reduced to shikimate (SKA) with NADP-dependent SKA dehydrogenase (SKDH) from the same organism. When SKDH was coupled with NADP-dependent D-glucose dehydrogenase (GDH) in the presence of excess D-glucose as an NADPH re-generating system, SKDH continued to produce SKA until 3-dehydroshikimate added initially in the reaction mixture was completely converted to SKA. Based on the data presented, a strategy for high SKA production was proposed.  (+info)

Granulibacter bethesdensis gen. nov., sp. nov., a distinctive pathogenic acetic acid bacterium in the family Acetobacteraceae. (32/68)

A Gram-negative, aerobic, coccobacillus to rod-shaped bacterium was isolated from three patients with chronic granulomatous disease. The organism was subjected to a polyphasic taxonomic study. A multilocus phylogenetic analysis based on the 16S rRNA gene, the internal transcribed spacer (ITS) region and the RecA protein demonstrated that the organism belongs to a new sublineage within the acetic acid bacteria in the family Acetobacteraceae. Phenotypic features are summarized as follows: the organism grew at an optimum temperature of 35-37 degrees C and optimum pH of 5.0-6.5. It produced a yellow pigment, oxidized lactate and acetate, the latter weakly, produced little acetic acid from ethanol and could use methanol as a sole carbon source. The two major fatty acids were a straight-chain unsaturated acid (C18:1omega7c) and C16:0. The DNA base composition was 59.1 mol% G+C. The very weak production of acetic acid from ethanol, the ability to use methanol, the yellow pigmentation and high optimum temperature for growth distinguished this organism from other acetic acid bacteria. The unique phylogenetic and phenotypic characteristics suggest that the bacterium should be classified within a separate genus, for which the name Granulibacter bethesdensis gen. nov., sp. nov. is proposed. The type strain is CGDNIH1T (=ATCC BAA-1260T=DSM 17861T).  (+info)