Fig 1.
SEM image of HC3 at 10000 × magnification.
Fig 2.
The neighbour-joining method cladogram showing a phylogenetic relationship between Sphingobium fuliginis HC3 and other related microorganisms in the genus Sphingobium and some deeply studied biphenyl/PCBs-degrading bacteria in other genera based on the 16S rDNA gene sequence analysis.
Microorganisms’ names are followed by the accession numbers.
Fig 3.
Degradation of various concentrations of biphenyl (10–1000 mg L−1) by HC3 in 24 hours.
Inoculation amount was 10% (v/v). Error bars represent mean ± standard deviation (n = 3).
Fig 4.
Time course of biphenyl degradation and cell growth of HC3.
Fig 5.
Effects of carbon sources on degradation of biphenyl (100 mg L−1) by HC3.
Control group: active cells 10% (v/v), no additional carbon source. Other groups: active cells 10% (v/v), glucose, sodium acetate, yeast extract or tryptone 1 g L-1. Error bars represent mean ± standard deviation (n = 3).
Fig 6.
The variation trends of biphenyl and benzoate in biphenyl degradation system at 0–220 min, qualitatively analyzed by GC-MS.
a. Biphenyl. b. Benzoate. Initial concentration of biphenyl was 15 mg L-1. The derivatization reagent was BSTFA-TMCS (99:1, v/v).
Fig 7.
The variation trends of 3-CBA in 3-CB degradation system at 0–5 h, quantitatively analyzed by GC-MS.
Initial concentration of 3-CB was 10 mg L-1. In control groups, HC3 cells were inactivated twice by autoclaving at 121°C for 30 min. The derivatization reagent was BSTFA-TMCS (99:1, v/v). Error bars represent mean ± standard deviation (n = 3).
Table 1.
Degradation of 10 PCB congeners by HC3 in 72 hours.
Table 2.
Degradation of mono-CBAs and benzoate by HC3 in 72 hours.
Table 3.
Degradation capacity of a wild type strain and a plasmid-cured strain of HC3.
Fig 8.
Agarose electrophoresis showing plasmid profile of HC3.
Line 1, DL2000 plus DNA Landder Marker; Line 2, plasmid-free (SDS cured), Line 3, HC3 plasmid DNA (no digestion); Line 4, HC3 plasmid DNA (EcoR I digestion); Line 5, HC3 plasmid DNA (Hind III digestion).