Isolation and characterization of benzene degradation strain Pseudomonas putida SW-3

Abstract:

[Objective] The objective of this study is to isolate a bacterium strain from industrial oil wastewater with benzene, toluene and styrene as the sole carbon source, then to analyze the degradation characteristics of the strain and to study the effect of substrate interaction on the degradation. [Methods] The strain was identified with physiological-biochemical and 16S rRNA gene sequence analysis; HS-GC was used to determine benzene series concentration; the degradation characteristics of the strain was analyzed by the hydrophobicity, emulsifying ability, oil displacement and transmission electron microscopy. [Results] The strain was identified as Pseudomonas putida, named SW-3. The maximum degradation rates of benzene, toluene and styrene were 0.072, 0.035 and 0.019 g/(L·h), and the total degradation rate of benzene mixture was 79.99% under the optimum degradation conditions. The interactions between substrates indicated that the degradation of toluene and styrene was stimulated by benzene, while the degradation of toluene was inhibited in the presence of styrene. The analysis about characteristics of adsorption, uptake and degradation of SW-3 suggested that SW-3 could transport the benzene by the energy-dissipating vesicle transport with the aid of the secreted surfactants. [Conclusion] Strain SW-3 has the ability to produce surfactants and degrade benzene compounds, and the interaction between substrates can significantly affect the degradation of different substrates.