The 490-bp band which was prevalent in biocontrol and environmental isolates, but was absent from clinical GSK2245840 in vitro isolates and from strain C9-1 is indicated by the arrow. Comparison of other genotypic and phenotypic traits Presence of traits that may reflect adaptation to the different lifestyles, such as sorbitol utilization, growth at
24°C and 37°C, and pantocin A or T3SS genes was determined Rabusertib in strains within theP. agglomerans sensu strictocluster and the two most-closely related groups represented by strains Eh252 and C9-1. At 37°C none of these three investigated parameters were significantly different between presumptive-clinical and plant isolates [i.e., maximal cell density (ODmax), maximal hourly growth rate (k max) and time needed to attain the maximal
hourly growth rate (t kmax)] (Figure6). In fact, the maximal hourly growth rate was slightly less in Y-27632 price clinical isolates, compared toPantoeabiocontrol or plant isolates. Similarly at 24°C, although clinical isolates had slightly lower maximal hourly growth rate compared to plant strains, differences were not significant (Figure6). All strains ofP. agglomeransgrew poorly at 37°C compared to growth at 24°C. Figure 6 Growth of Pantoea strains at 37°C and 24°C. Maximal growth (A) and maximal hourly growth rate (B) of different isolates clustering withP. agglomeransLMG 1286Tin therrstree at 37°C. 0.25 OD420-580 nmunits correspond to about 108CFU/ml. The average values for maximal hourly growth rate (κmax) and maximal cell density (ODmax) as well as the time needed to attain maximal hourly growth rate (tkmax, expressed in days) are shown in (C). The asterisk indicates a statistical difference (two-tailed t-test) between clinical and other isolates (i.e., environmental, biocontrol and plant pathogenic isolates). Utilization of sorbitol byP. agglomeransas a sole carbon source was restricted to only a few biocontrol
Ceramide glucosyltransferase isolates, indicating this as an important feature for phytopathogen antagonism. In addition to the commercial biocontrol strain C9-1, which has two plasmid-encoded sorbitol-utilization operons , only the biocontrol strains Eh252 and P10c were able to efficiently metabolize sorbitol. StrainP. ananatisLMG 2665T, included as a positive control for sorbitol utilization, andP. agglomeransstrains C9-1 and Eh252 gave absorbance readings that indicated a growth after 6-8 h from inoculation, while the lag-phase of P10c was protracted up to 24 h, suggesting that a certain signal may be required for this strain before C6-sugar metabolism is triggered. Pantocin A biosynthetic genes were amplified in just four biocontrol isolates (i.e., C9-1, Eh252, Eh318 and CPA-2) and one clinical strain LMG 5343. Genome sequence analysis of C9-1 has revealed that in this strain the gene cluster coding for pantocine production is situated on a low-GC genomic island of about 29 kbp inserted between themutSandnarLgenes, which was probably acquired by horizontal gene transfer .