Teizi Urakami

Transfer of pseudomonas plantarii and Pseudomonas glumae to Burkholderia as Burkholderia spp. and description of Burkholderia vandii sp. nov

Plant-associated bacteria were characterized and are discussed in relation to authentic members of the genus Pseudomonas sensu stricto. Bacteria belonging to Pseudomonas rRNA group II are separated clearly from members of the genus Pseudomonas sensu stricto (Pseudomonas fluorescens rRNA group) on the basis of plant association characteristics, chemotaxonomic characteristics, DNA-DNA hybridization data, rRNA-DNA hybridization data, and the sequences of 5S and 16S rRNAs. The transfer of Pseudomonas cepacia, Pseudomonas mallei, Pseudomonas pseudomallei, Pseudomonas caryophylli, Pseudomonas gladioli, Pseudomonas pickettii, and Pseudomonas solanacearum to the new genus Burkholderia is supported; we also propose that Pseudomonas plantarii and Pseudomonas glumae should be transferred to the genus Burkholderia. Isolate VA-1316T (T = type strain) was distinguished from Burkholderia species on the basis of physiological characteristics and DNA-DNA hybridization data. A new species, Burkholderia vandii sp. nov. is proposed for this organism; the type strain of B. vandii is VA-1316 (= JCM 7957).

Protomonas, a New Genus of Facultatively Methylotrophic Bacteria

A new genus and species of facultatively methylotrophic bacteria are described. These bacteria are polarly flagellated, gram-negative, nonsporeforming, rod-shaped organisms that occur singly and in pairs. Carotenoid pigment and bacteriochlorophyll are formed in the cells. The deoxyribonucleic acid base composition is 65 to 67 mol% guanine plus cytosine. The cellular fatty acids consist of a large amount of straight-chain unsaturated C18:1 acid and small amounts of straight-chain saturated C16:1 acid, C19:0 cyclopropane acid, and 3-OH-C14:0 hydroxy acid. The major ubiquinone is Q-10. Ubiquinones Q-8, Q-9, and Q-11 are present as minor components. A new genus, Protomonas, is proposed to include this group of methylotropic bacteria. The type species of the genus Protomonas is Protomonas extorquens comb. nov., with type strain TK 0001 (=DSM 1337 = NCIB 9399).

Paracoccus aminophilus sp. nov. and Paracoccus aminovorans sp. nov., Which Utilize N,N-Dimethylformamide

Two methylamine- and N,N-dimethylformamide-utilizing Paracoccus spp. are described. These bacteria are gram-negative, nonsporeforming, nonmotile, coccoid or short rod-shaped organisms. Their DNA base composition is 62 to 68 mol% G + C. Their cellular fatty acids include large amounts of C18:1 acid. Their major hydroxy acids are 3-OH C10:0 and 3-OH C14:0 acids. The major ubiquinone is Q-10. These bacteria are distinguished from Paracoccus denitrificans and Paracoccus alcaliphilus by physiological characteristics and by DNA-DNA-homology. Paracoccus aminophilus sp. nov. and Paracoccus aminovorans sp. nov. are proposed. The type strain of P. aminophilus is DM-15 (= JCM 7686), and the type strain of P. aminovorans is DM-82 (= JCM 7685). Paracoccus halodenitrificans is distinguished from other Paracoccus species on the basis of cellular fatty acid composition, hydroxy fatty acid composition, and DNA-DNA homology. It may not be a valid member of the genus Paracoccus.

Acidomonas gen. nov., Incorporating Acetobacter methanolicus as Acidomonas methanolica comb. nov.

A new genus of acidophilic, facultatively methylotrophic bacteria is described. These organisms are gram-negative, nonsporeforming, nonmotile, and rod shaped and grow at pH 2.0 to 5.5. These characteristics are unique among the methanol-utilizing bacteria. The deoxyribonucleic acid base composition is 63 to 65 mol% guanine plus cytosine. Acetobacter methanolicus TK 0705T (T = type strain) is a typical strain in this group. These bacteria are distinguished from type and representative strains of Acetobacter, Gluconobacter, Acidiphilium, and Thiobacillus on the basis of deoxyribonucleic acid-deoxyribonucleic acid homology. A new genus, Acidomonas, is proposed to include this group of methylotrophic bacteria. The type species of the genus Acidomonas is Acidomonas methanolica comb, nov., with type strain TK 0705 (= IMET 10945).

Trace levels of pyrroloquinoline quinone in human and rat samples detected by gas chromatography/mass spectrometry

A detailed procedure for the assay of free pyrroloquinoline quinone (PQQ) in human and rat samples by gas chromatography/mass spectrometry (GC/MS) has been established with stable-isotopic PQQ as internal standard. PQQ was extracted from the samples, after addition of the internal standard, with butanol under acid conditions and with Sep-Pak C18 cartridges. After derivatization of PQQ with phenyltrimethylammonium hydroxide, molecular peaks at m/z 448 and 462 were used for detection of PQQ and [U-13C]PQQ by selected ion monitoring, respectively. Trace amounts of free PQQ were detected in eight organs, plasma and urine of the human, and in three organs of the rat. The PQQ level was highest in the human spleen (5.9 +/- 3.4 ng/g tissue, followed by the pancreas and lung, and it was below detection limits for human brain and heart. Trace levels of PQQ were also found in rat small intestine, liver and testis. Our data are far below those measured by the redox cycling method of Gallops group for human plasma, adrenal and urine.

Degradation of Polylactide by Commercial Proteases

Fifty-six commercially available proteases were tested for polylactide-degrading activity. Little or no activity was found in acid and neutral proteases, while some alkaline proteases formed appreciable amounts of lactic acid from polylactide. These polylactide-degrading proteases were derived from Bacillus species and had catalytic activity even under neutral, as well as alkaline, conditions. Savinase (Novo Nordisk) degraded polylactide the fastest among the enzymes tested and its specific activity corresponded to about one-half of proteinase K. Polylactide-degrading activity was not always present in the enzymes that affected keratin, while polylactide-degrading proteases commonly hydrolyzed keratin. A significant correlation was observed between degrading activities of polylactide and keratin in alkaline proteases.

Characterization and Description of Hyphomicrobium denitrificans sp. nov.

The Hyphomicrobium strains which we examined in this study are gram negative and facultatively methylotrophic and utilize methanol and monomethylamine, but not methane, by the serine pathway with activated formaldehyde incorporation. The cellular fatty acids include a large amount of straight-chain unsaturated C18:1 acid, and the hydroxy fatty acids include large amounts of 3-OH C14:0 and 3-OH C16:0 hydroxy acids. The major ubiquinone is ubiquinone Q-9. However, the DNA base compositions of these Hyphomicrobium strains are heterogeneous, ranging from 58 to 66 mol% guanine plus cytosine. Strains TK 0415T (T = type strain), TK 0414, TK 0416, and TK 0441 were distinguished from other Hyphomicrobium strains on the basis of physiological characteristics and DNA-DNA hybridization data. A new species, Hyphomicrobium denitrificans, is proposed for these organisms; the type strain of H. denitrificans is TK 0415 (= DSM 1869 = NCIB 11706 = Attwood and Harder strain X).

Further Studies of the Genus Methylobacterium and Description of Methylobacterium aminovorans sp. nov.

Pink-pigmented facultatively methylotrophs belonging to the genus Methylobacterium were examined in this study. Methylobacterium strains are divided into eight species on the basis of phenotypic characteristics. This division is supported by the results of DNA-DNA homology experiments. On the basis of DNA relatedness and other characteristics, a new species, Methylobacterium aminovorans, is proposed. The type strain of M. aminovorans is strain TH-15 (= JCM 8240).

Microbial degradation of poly(3-hydroxybutyrate) and polycaprolactone by filamentous fungi

Five strains were isolated from soil as fungi able to degrade both poly(3-hydroxybutyrate) (PHB) and polycaprolactone (PCL), and one of the strains, D218, identified as Paecilomyces lilacinus, was selected. In 10 d, D218 degraded PHB almost completely and 10% of the PCL, each at 0.1% in the culture media. Strain D218 excreted PHB and PCL depolymerases in media containing either PHB, PCL or PHB plus PCL. Both depolymerase activities were reduced when the medium was supplemented with either soluble starch, lactose or glucose. The optimum conditions for PHB depolymerase were pH 6.5 to 7.5 at 50°C, while those for PCL depolymerase were pH 3.5 to 4.5 at 30°C. In the reaction mixtures used for the enzyme assays, the formation of 3-hydroxybutyrate from PHB and e-caprolactone from PCL was confirmed by high performance liquid chromatography.

Transfer of Pseudomonas aminovorans (den Dooren de Jong 1926) to Aminobacter gen. nov. as Aminobacter aminovorans comb. nov. and Description of Aminobacter aganoensis sp. nov. and Aminobacter niigataensis sp. nov.

We compared non-methane-, non-methanol-, and methylamine-utilizing bacteria, including Pseudomonas aminovorans, a tetramethylammonium-utilizing bacterium, and an N-N-dimethylformamide-utilizing bacterium. These bacteria are gram-negative, nonsporeforming, subpolarly flagellated, rod-shaped organisms. Reproduction occurs by budding. The DNA base compositions are 62 to 64 mol% guanine plus cytosine. The cellular fatty acids contain a large amount of C18:1 acid. The major hydroxy acid is 3-OH C12:0 acid. The major ubiquinone is ubiquinone Q-10. These bacteria are clearly separated from authentic Pseudomonas species (Pseudomonas fluorescens rRNA group) on the basis of utilization of methylamine, morphological and chemotaxonomic characteristics, DNA-DNA homology, and rRNA-DNA homology. They were divided into three subgroups on the basis of their physiological characteristics and DNA-DNA homology data. A new genus, Aminobacter, and three new species, Aminobacter aminovorans comb. nov., Aminobacter aganoensis sp. nov., and Aminobacter niigataensis sp. nov., are proposed. The type species of Aminobacter gen. nov. is A. aminovorans, with type strain JCM 7852. The type strain of A. aganoensis is strain TH-3 (= JCM 7854), and the type strain of A. niigataensis is strain DM-81 (= JCM 7853).