Table 1.
Minimal inhibitory concentration (MIC) of IBP obtained for the tested actinobacterial strains.
Table 2.
Percentage of IBP (100 mg/L) remaining during biodegradation experiment after 7 days of incubation of the actinobacterial strains in the RS medium.
Fig 1.
Biodegradation rate of IBP (A), carbon dioxide release (B) and oxygen uptake (C) by R. cerastii IEGM 1278. 1 –dry weight (CDW) of rhodococcal biomass in the presence of IBP and n-hexadecane; 2 –dry weight of rhodococcal biomass in the presence of n-hexadecane. Cells were pre-grown in NB for 3 days. Biodegradation experiments were conducted in the RS medium supplemented with 0.1% n-hexadecane. The graph shows mean values ± SD of three experiments done in triplicate.
Fig 2.
Biodegradation rate of IBP by R. cerastii IEGM 1278 in a laboratory bioreactor.
Biodegradation experiments were conducted in the RS medium supplemented with 0.1% n-hexadecane. The graph shows mean values ± SD of three experiments.
Fig 3.
Biodegradation rate of IBP by native and pre-incubated R. cerastii IEGM 1278 cells.
1 –dry weight (CDW) of biomass in the presence of IBP and n-hexadecane; 2 –dry weight of biomass in the presence of n-hexadecane. Biodegradation experiments were conducted in the RS medium supplemented with 0.1% n-hexadecane. The graph gives mean values ± SD of three experiments done in triplicate.
Fig 4.
Proposed scheme of IBP biotransformation by R. cerastii IEGM 1278.
1 –ibuprofen sodium salt; 2 –ibuprofen; 3–9-hydroxy ibuprofen; 4–6,9-dihydroxy ibuprofen; 5–6-hydroxy ibuprofen; 6 –decarboxylated derivative of 9-hydroxy ibuprofen; 7 –decarboxylated derivative of 6,9-dihydroxy ibuprofen; 8 –decarboxylated derivative of 6-hydroxy ibuprofen. The numbering of IBP atoms proposed by Preskar et al. is used [88].
Table 3.
Experimental phytotoxicity of IBP and its biotransformation products.
Table 4.
Toxicity of IBP (1–2) and its biotransformation products (3–7) calculated using ECOSAR.
Table 5.
Soil sorption, bioconcentration and bioaccumulation of IBP and its transformation products calculated using EPI Suite.
Table 6.
Biodegradability of IBP and its biotransformation products calculated using EPI Suite.
Fig 5.
Cell aggregates of R. cerastii IEGM 1278.
A–culture flask; B–phase-contrast image, x 1,000. 1 –cords; 2 –bacterial cells. Cells were grown for 3 days in the RS medium supplemented with 0.1% n-hexadecane and 100 mg/L IBP.
Fig 6.
CLSM (A) and AFM (B, C) images and profiles (D) of R. cerastii IEGM 1278. Cells were grown for 24 h in the RS medium supplemented with 0.1% n-hexadecane (I) and 100 mg/L IBP and 0.1% n-hexadecane (II). The scale bars on the CLSM images correspond to 5 μm.
Fig 7.
CLSM (A) and AFM (B, C) images and profiles (D) of R. cerastii IEGM 1278. Cells were grown for 4 days in the RS medium supplemented with 0.1% n-hexadecane (I) and 100 mg/L IBP and 0.1% n-hexadecane (II). The scale bars on the CLSM images correspond to 5 μm.
Table 7.
Morphometric parameters of R. cerastii IEGM 1278 cells grown in the RS medium supplemented with IBP and n-hexadecane.
Fig 8.
Correlation of membrane permeability with zeta potential of R. cerastii IEGM 1278.
Cells were grown in the RS medium supplemented with 0.1% n-hexadecane (A) and 100 mg/L IBP and 0.1% n-hexadecane (B).