Pseudomonas kuykendallii sp. nov.: A Novel γ-Proteobacteria Isolated From a Hexazinone Degrading Bioreactor


Three strains of Gram-negative bacteria designated strains H2T, H6, and H7 were isolated from bioreactors that degraded the herbicide hexazinone. Similar morphological characteristics, cellular fatty acid profiles, and 16S rRNA gene sequences show that the isolates are members of the same species. These characteristics also show that the isolates belong to the genus Pseudomonas with P. graminis, P. putida, and P. stutzeri as close relatives. The 16S rRNA gene of the H2T strain differed from that of type strains for P. graminis, P. putida, and P. stutzeri by 1.9, 2.5, and 2.7 %, respectively, indicating that the H2T, H6, and H7 strains are related to P. graminis, P. putida, and P. stutzeri but are different enough to represent a novel species. The G+C content of the three strains averaged 61.2 ± 0.8 mol% which is similar to the values reported for P. graminis (61), P. putida (61.6), and P. stutzeri (62.2–65.5). The major cellular fatty acids present in the H2T strain were C18:1 ω7c/C 18:1 ω6c (34.3 %), C16:1 ω6c/C16:1 ω7c (27.4 %), C16:0 (20.6 %), C12:0 (7.9 %), C12:0 3-OH (4.5 %), and C10:0 3-OH (3.1 %). The name Pseudomonas kuykendallii sp. nov. is proposed for these bacteria.

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The authors thank Robin Montenieri and Mia Hanson for their expert technical assistance. Manufacturer and product brand names are given for the reader’s convenience and do not reflect endorsement by the US government. USDA is an equal opportunity provider and employer. This article was the work of US government employees engaged in official duties and is exempt from copyright.

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Correspondence to William J. Hunter.

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Hunter, W.J., Manter, D.K. Pseudomonas kuykendallii sp. nov.: A Novel γ-Proteobacteria Isolated From a Hexazinone Degrading Bioreactor. Curr Microbiol 65, 170–175 (2012).

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  • Adipic Acid
  • Cellular Fatty Acid
  • Hexazinone
  • Dominant Fatty Acid
  • Acetoin Production