Hyphomicrobium Denitrificans Research Articles

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).