Strain Y24T was isolated from a cold spring water (E
85°22′ 35″, N 43°50′ 30″) sample by dilution plating on
TYEG agar (10 g tryptone, 5 g yeast extract, 5 g glucose,
3 g K2HPO4 and 20 g agar in 1,000 ml distilled water, pH
7.0), and incubated at 10 °C for 3 days. Strain H9T was
originally isolated from carrot (Daucus carota) on a TYEG
agar plate. The carrot was prepared according to the following
procedure, as described by Li et al. (2007). Carrot was
washed with tap water, surface sterilized with 75 % ethanol
for 3 min and 2.6 % sodium hypochlorite solution for 5 min
and 75 % ethanol for 1 min again, then rinsed with sterile
double-distilled water (ddH2O). The isolates were routinely
maintained on TYEG agar slants at 4 °C and preserved as
suspensions of cells in glycerol (20 %, v/v) at −80 °C, as
their closely related type strain P. hunanensis FeL05T,
which was obtained from Institute of Agricultural Resources
and Regional Planning, Chinese Academy of Agricultural
Sciences. Biomass for chemotaxonomic and molecular systematic
studies was prepared by growing the strains in shake
flasks (~150 rpm) of TYEG broth at 30 °C for 3 days.