Acidovorax valerianellae sp. nov., a novel pathogen of lamb's lettuce [Valerianella locusta (L.) Laterr.]

Abstract

A numerical taxonomic analysis of the 19 lamb's lettuce strains showed a single homogeneous phenon closely related to previously described phytopathogenic taxa of the genus Acidovorax. DNA-DNA hybridization studies showed that the lamb's lettuce strains were 91-100 % related to a representative strain, strain CFBP 4730 T , and constituted a discrete DNA hybridization group, indicating that they belong to the same novel species. Results from DNA-rRNA hybridization, 16S rRNA sequence analysis and fatty acid analysis studies confirmed that this novel species belongs to the b-subclass of the Proteobacteria and, more specifically, to the family Comamonadaceae and the genus Acidovorax. The name Acidovorax valerianellae sp. nov. is proposed for this novel taxon of phytopathogenic bacteria. The type strain is strain CFBP 4730 T (=NCPPB 4283 T ).

Verminephrobacter eiseniae gen. nov., sp. nov., a nephridial symbiont of the earthworm Eisenia foetida (Savigny)

“…DNA samples from A. temperans and A. delafieldii were used as controls. The DNA G+C content (determined for isolates EF01-1, EF01-2 T , EF02-2 and EF05-1) was 67.0±0.2 mol%, well within the 60-72 mol% values reported for other species of the genus Acidovorax (Schulze et al, 1999;Gardan et al, 2000Gardan et al, , 2003, and in close agreement with the 65.2 mol% observed for the genome sequence of isolate EF01-2 (unpublished observations).…”

“…Acidovorax-like 16S rRNA gene sequences are frequently recovered from wastewater treatment plants and other aquatic environments (Schweitzer et al, 2001;Hoshino et al, 2005;Manefield et al, 2005). The genus Acidovorax includes species isolated from soil and sludge (Willems et al, 1990;Schulze et al, 1999;Heylen et al, 2008), in addition to a group of plant pathogens with a varied host range (Willems et al, 1992;Gardan et al, 2000Gardan et al, , 2003. The present study reports the isolation and characterization of a relative of the genus Acidovorax from the nephridia of E. foetida.…”

“…None of the novel symbiotic strains tested were capable of growth on ACM under anoxic conditions, even in the presence of the alternative electron acceptors tested. Recognized species of the genus Acidovorax, except for A. valerianellae (Gardan et al, 2003) are capable of respiring nitrate.…”

“…The mean 16S rRNA gene sequence similarity between the earthworm symbionts and either of the other two groups within the genus Acidovorax (92.5±0.5 % and Willems et al, 1992);3, A. konjaci (n53;Willems et al, 1992);4, A. defluvii (n58;Schulze et al, 1999);5, A. delafieldii (n514;Willems et al, 1990);6, A. facilis (n54;Willems et al, 1990);7, A. temperans (n518;Willems et al, 1990);8, A. valerianellae (n519;Gardan et al, 2003). Catalase 2 (2) 93.3±0.3 % similarity to plant pathogens and other species within the genus, respectively) fell within the range observed at a genus rank (Konstantinidis & Tiedje, 2005b) and was well below that shared among other species in the genus.…”

Pseudacidovorax intermedius gen. nov., sp. nov., a novel nitrogen-fixing betaproteobacterium isolated from soil

“…Strain CC-21 T showed high amounts of C 16 : 0 , summed feature 3 (C 16 : 1 v7c/C 15 : 0 iso 2-OH) and C 18 : 1 v7c, as reported for strains of the genera Acidovorax, Alicycliphilus, Giesbergeria, Simplicispira and Diaphorobacter, but also showed relatively high amounts (.8 %) of C 17 : 0 cyclo, which is not reported in Giesbergeria or Simplicispira species (Grabovich et al, 2006), and only in small amounts in species of Acidovorax (Gardan et al, 2003;Schulze et al, 1999;Willems et al, 1990) and Alicycliphilus (Mechichi et al, 2003). In addition, C 8 : 0 3-OH was found, a hydroxylated fatty acid that is not detected in Alicycliphilus, Giesbergeria, Simplicispira or Diaphorobacter, but found in Acidovorax (Gardan et al, 2003;Grabovich et al, 2006;Willems et al, 1990). The presence of the hydroxylated fatty acids C 16 : 1 2-OH and C 18 : 1 2-OH distinguished strain CC-21 T from all other related genera.…”