Project description:25 ml of a modified basal salts medium (BSM; Hareland et al. 1975, J Bacteriol 121:272) supplemented with 0.05% casamino acids (Becton & Dickinson, Sparks, USA), 0.05 % yeast extract (Oxoid, Basingstoke, UK) and 0.4 % glucose (Fisher Scientific, Loughborough, UK) flasks were inoculated with 2 x 10^8 CFU and incubated at 30M-0C on an orbital shaker at 150 rpm. Growth was monitored spectrophotometrically. Burkholderia lata strains evaluated were: strain 383 (LMG22485) and strain 383-CMIT (a spontaneous mutant with increased tolerance to a commercially available blend of 3:1 methylisothiazolinone & chloromethylisothiazolinone preservatives). Sub-inhibitory concentrations of preservatives added at the time of inoculation were: 0.003% dimethylol dimethyl hydantoin (DDH, Lonza Ltd, Basal, Switzerland) or 0.01 % methylisothiazolinone/chloromethylisothiazolinone (MIT/CMIT, Romm & Haas, Coventry, UK). Only B. lata strain 383 was cultured with dimethylol dimethyl hydantoin. Strain 383 cultivated without preservatives was used as control condition.<br>Cultures were harvested at mid-exponential growth phase (optical density of 0.5, 2 x 10^8 CFU), promptly aliquoted into a microcentrifuge tube and immediately snap-cooled in liquid nitrogen before centrifuging at 20.000 x g at 4M-:C for 1 min. Pellets were immediately frozen at -80M-:C.<br>
