Article Figures & Data
Figures
- FIG. 1.
(A) First enrichment culture of PCNB-degrading bacteria in Charcoal A100 using a soil-charcoal perfusion method. (B) Secondary enrichment culture using a charcoal perfusion method. Changes in concentration of PCNB (○) and chloride ions (▪) in culture fluid are indicated. Down arrows indicate the time points of replacement of perfusion fluid. Concentrations of PCNB at the initial point and replacement points are calculated values of the added PCNB.
- FIG. 2.
Phylogenetic affiliation based on the 16S rRNA sequence data, showing the relationship of strain PD653 to the most closely related genera. The GenBank accession numbers are provided in parentheses. The dendrogram was generated by the neighbor-joining method. The numbers at the branch points are bootstrap values based on 1,000 trials; the bar indicates 10 nucleotide substitutions per 1,000 nucleotide positions. Species included in the analysis are Actinoplanes philippinensis (D85474), Actinoplanes rectilineatus (AB037010), Aeromicrobium erythreum (AF005021), Aeromicrobium fastidiosum (Z78209), Marmoricola aurantiacus (Y18629), Nocardioides albus (AF005002), Nocardioides aquiterrae (AF529063), Nocardioides jensenii (Z78210), Nocardioides luteus (AF005007), Nocardioides nitrophenolicus (AF005024), Nocardioides plantarum (Z78211), Nocardioides pyridinolyticus (U61298), Pimelobacter (Nocardioides) simplex (AF005013), and Rhodococcus globerulus (X81931) as an outlier.
- FIG. 3.
Aerobic degradation of HCB by Nocardioides sp. strain PD653 in the MM. The changes in the OD600 of strain PD653 (▴) and evolution of chloride ions (□) in accordance with the HCB degradation (•) are demonstrated. OD600 and concentrations of the materials are mean values of the duplicate experiments. Error bars indicate standard deviations (SD).
- FIG. 4.
Mineralization of 14C-HCB by Nocardioides sp. strain PD653. Disappearance of 14C-HCB (•) and evolution of 14C-labeled unidentified water soluble metabolites (□) and 14CO2 (▴) are demonstrated. Volatile 14C-HCB (○) captured on the PUF column is also shown. Radioactivity of the materials is mean value of the duplicate experiments and is expressed as the percentage of that of the initial applied 14C. Error bars indicate the SD.
- FIG. 5.
Generation of PCP accompanied by degradation of HCB by resting cells of Nocardioides sp. strain PD653. The time courses of disappearance of HCB (•) and generation of PCP (▴) are demonstrated. The concentrations of HCB (○) and PCP (▵) in heat-killed control cultures are also demonstrated. Mean values (n = 3) and the SD of concentrations of the materials are shown.
- FIG. 6.
GC-MS analysis of metabolites obtained from degradation of PCP by resting cells of Nocardioides sp. strain PD653. Acetylated derivatives of the metabolites were analyzed. The scanning was carried out at a mass range of 50 to 600 (m/z).
- FIG. 7.
Possible metabolic pathway of HCB by Nocardioides sp. strain PD653 under strict aerobic conditions according to the results of resting-cell treatment of spiked HCB and PCP. PCP, tetrachlorohydroquinone (TeCH), and dichlorohydroquinone (DiCH) are shown as intermediates of mineralization of HCB. All structures of the compounds were identified by GC-MS comparison with authentic compounds.
