• Korean Journal of Microbiology
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• v.54 no.1
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• pp.46-52
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• 2018

Biodegradation pathway of dibenzofuran (DBF) of Novosphingobium pentaromativorans US6-1, a high-molecular-weight polycyclic aromatic hydrocarbons degrading strain, was investigated via analysis of metabolic intermediates and transcriptome. As a result, 3(2H)-benzofuranone, a basic skeleton of the metabolic intermediates produced by lateral dioxygenation process, was detected as an intermediate. RNA-Seq analysis confirmed that most of the expressed genes upon exposure to DBF were related to the lateral degradation pathway. Based on these results, the biodegradation pathway of DBF by N. pentaromativorans US6-1 was proposed.

• Journal of the Korean Society for Marine Environment & Energy
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• v.7 no.3
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• pp.146-151
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• 2004

Cyclodextrin compounds including 2-hydroxypropyl-β-cyclodextrin(β-HPCD) though to be accelerate the biodegradation of PAHs molecule by increasing solubility of PAHs through detaining PAHs in their's cavity. However, only this mechanism is not sufficient to explain the enhancement of PAHs biodegradation by β-HPCD. To find out possible additional role of β-HPCD in the enhancement of PAHs biodegradation, biodegradation rates of pyrene and benzo[a]pyrene (B[a]P) by a PAHs degrading Novosphingobium pentaromtivorans US6-1 strain were compared between with and without addition of β-HPCD. Changes of bacterial biomass were also measured simultaneously. In addition catechol 1,2-dioxygenase activity was determined depending on pre-incubation conditions. As a result, β-HPCD accelerate the degradation rate of pyrene by strain US6-1 and especially the β-HPCD amendment was obligatory for the degradation of B[a]p. Bacterial biomass was responsible for β-HPCD, however, PAHs compounds such as pyrene and B[a]P did not contribute to the bacterial biomass. Catechol 1,2-dioxygenase specific activity of US6-l cells pre-cultured in MM2 medium containing l％ β-HPCD was higher than that of cells pre-cultured in ZoBell medium. The former case also showed similar activity compared to that of cells serially starved in MM2 medium after grown in ZoBell medium. These results imply that the presence of β-HPCD accelerate the degradation of PAHs by increasing the bacterial biomass as well as by increasing the water solubility of PAHs.