%0 Journal Article %A Chan, Yiu-Kwok %A Wheatcroft, Roger %A Watson, Robert J. %T Physiological and Genetic Characterization of a Diazotrophic Pseudomonad %D 1986 %J Microbiology, %V 132 %N 8 %P 2277-2285 %@ 1465-2080 %R https://doi.org/10.1099/00221287-132-8-2277 %I Microbiology Society, %X Summary: A soil isolate, 4B, which had been previously assigned to the genus Pseudomonas and shown to be capable of reducing C2H2 with simple phenolic compounds as sole carbon source, was further characterized in comparison with two other diazotrophs which were identified as pseudomonads. The DNA base composition of 4B was 60·2 mol% G + C. Plasmid DNA was not detected in alkaline SDS lysates of 4B by agarose gel electrophoresis. Comparable maximum C2H2 reduction activities in 4B were observed under microaerobic conditions (pO2 about 0·003 atm) with either 28 mM-glucose or 5 mM-protocatechuate as carbon source. N2 fixation was confirmed by the cellular incorporation of 15N2 in cultures of 4B grown in N-free medium. Extensive biochemical tests, including the carbon utilization pattern, demonstrated that 4B was closely related to Pseudomonas delafieldii (ATCC 17505) although the latter did not fix N2. 4B had metabolic patterns different from the two other strains reported to be diazotrophic pseudomonads; all three contained DNA homologous to the nifHDK genes of Klebsiella pneumoniae M5A1. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-132-8-2277