Fig 1.
Growth curves of bacteria in BM medium based on OD630.
A) P. putida KT2440 and B) E. coli BL21 were grown in BM medium with either 20 mM citrate or 20 mM citrate and 1 mg⋅mL-1 Impranil for 25 hours at 30°C, 180 rpm in a microplate reader. Biotic controls correspond to bacterial cultures without any carbon source. The data are the mean of three independent experiments performed in duplicate. Error bars indicate the standard deviation (SD).
Fig 2.
putida KT2440 grown in BM-citrate-Impranil tend to form aggregates (see C-3).
P. Photographs of microplate wells containing cultures of P. putida KT2440, and E. coli in BM medium added with either citrate or citrate-Impranil after 24 h of incubation at 30°C, 180 rpm. Differences in the color of cultures in wells are due to the presence of Impranil (compare 2-BM-citrate with 3-BM-citrate-Impranil), E. coli BL21 inocula, or the growth of P. putida KT2440 using citrate or citrate-Impranil as carbon sources.
Fig 3.
Metabolically active P. putida KT2440 cells reduce the XTT salt to a soluble, orange-colored formazan.
Photographs of microplate wells containing cultures of P. putida KT2440 and E. coli grown in BM medium added with either citrate or citrate-Impranil and XTT after 25 hours of incubation. The intensity of the orange formazan is directly proportional to the number of active cells. E. coli BL21 negative control and abiotic controls did not show XTT reduction.
Fig 4.
Kinetics of orange-colored formazan production based on OD470.
50 μL of XTT (2 mg⋅mL-1) were added to the cultures in microplates of (A) P. putida KT2440 and (B) E. coli BL21 described in the legend of Fig 1. The data are the mean of the corrected absorbance (OD470-OD630) of three independent experiments performed in duplicate. Error bars; SD.
Fig 5.
FTIR spectra of Impranil treated with P. putida KT2440 for 0 and 15 days of incubation.
Changes in functional groups are observed. The FTIR spectra show the average of three biological replicates for each sampling day averaged with Spectragryph software.