Background α,β-Unsaturated aldehydes are widely used in the organic synthesis of fine chemicals for application in products such as flavoring agents, fragrances and pharmaceuticals. In the selective oxidation of α,β-unsaturated alcohols to the corresponding α,β-unsaturated aldehydes, it remains challenging to overcome poor selectivity, overoxidation and a low atom efficiency in chemical routes. Results An E. coli strain coexpressing the NADP+-specific alcohol dehydrogenase YsADH and the oxygen-dependent NADPH oxidase TkNOX was constructed; these components enabled the NADP+ regeneration and catalyzed the oxidation of 100 mM 3-methyl-2-buten-1-ol to 3-methyl-2-butenal with a yield of 21.3%. The oxygen supply was strengthened by introducing the hemoglobin protein VsHGB into recombinant E. coli cells and replacing the atmosphere of the reactor with pure oxygen, which increased the yield to 51.3%. To further improve catalytic performance, the E. coli cells expressing the multifunctional fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB were generated, which completely converted 250 mM 3-methyl-2-buten-1-ol to 3-methyl-2-butenal after 8 h of whole-cell oxidation. The reaction conditions for the cascade biocatalysis were optimized, in which supplementation with 0.2 mM FAD and 0.4 mM NADP+ was essential for maintaining high catalytic activity. Finally, the established whole-cell system could serve as a platform for the synthesis of valuable α,β-unsaturated aldehydes through the selective oxidation of various α,β-unsaturated alcohols. Conclusions The construction of a strain expressing the fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB achieved efficient NADP+ regeneration and the selective oxidation of various α,β-unsaturated alcohols to the corresponding α,β-unsaturated aldehydes. Among the available redox enzymes, the fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB has become the most recent successful example to improve catalytic performance in comparison with its separate components.

Background: α,β-Unsaturated aldehydes are widely used in the organic synthesis of fine chemicals for application in products such as flavoring agents, fragrances and pharmaceuticals. In the selective oxidation of α,β-unsaturated alcohols to the corresponding α,β-unsaturated aldehydes, it remains challenging to overcome poor selectivity, overoxidation and a low atom efficiency in chemical routes. Results: An E. coli strain coexpressing the NADP+-specific alcohol dehydrogenase YsADH and the oxygen-dependent NADPH oxidase TkNOX was constructed; these components enabled the NADP+ regeneration and catalyzed the oxidation of 100 mM 3-methyl-2-buten-1-ol to 3-methyl-2-butenal with a yield of 21.3%. The oxygen supply was strengthened by introducing the hemoglobin protein VsHGB into recombinant E. coli cells and replacing the atmosphere of the reactor with pure oxygen, which increased the yield to 51.3%. To further improve catalytic performance, the E. coli cells expressing the multifunctional fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB were generated, which completely converted 250 mM 3-methyl-2-buten-1-ol to 3-methyl-2-butenal after 8 h of whole-cell oxidation. The reaction conditions for the cascade biocatalysis were optimized, in which supplementation with 0.2 mM FAD and 0.4 mM NADP+ was essential for maintaining high catalytic activity. Finally, the established whole-cell system could serve as a platform for the synthesis of valuable α,β-unsaturated aldehydes through the selective oxidation of various α,β-unsaturated alcohols. Conclusions: The construction of a strain expressing the fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB achieved efficient NADP+ regeneration and the selective oxidation of various α,β-unsaturated alcohols to the corresponding α,β-unsaturated aldehydes. Among the available redox enzymes, the fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB has become the most recent successful example to improve catalytic performance in comparison with its separate components.

Background: α,β-unsaturated aldehydes are widely used in as organic synthesis of fine chemicals such as flavor, fragrances and pharmaceuticals. The selective oxidation of α,β-unsaturated alcohols to the corresponding α,β-unsaturated aldehydes remains challenging to overcome poor selectivity, over-oxidation and low atom efficiency in chemical routes. Results: An E. coli strain co-expressing NADP+-specific alcohol dehydrogenase YsADH and oxygen-dependent NADPH oxidase TkNOX was constructed, which enabled the NADP+ regeneration and catalyzed the oxidation of 100 mM 3-methyl-2-buten-1-ol to 3-methyl-2-butenal with the yield of 21.3%. The oxygen supply was strengthened by introducing the hemoglobin VsHGB into recombinant E. coli cells and replacing the atmosphere of the reactor with pure oxygen, which increased the yield up to 51.3%. To further improve catalytic performance, the E. coli cells expressing the multifunctional fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB were achieved, which totally converted 250 mM 3-methyl-2-buten-1-ol to 3-methyl-2-butenal after 8 h of whole-cell oxidation. The reaction conditions of the cascade biocatalysis were optimized, in which the supplement of 0.2 mM FAD and 0.4 mM NADP+ was essential for maintaining high catalytic activity. Finally, the established whole-cell system could serve as a platform for the synthesis of valuable α,β-unsaturated aldehydes from selective oxidation of various α,β-unsaturated aldehydes. Conclusions: The construction of the strain expressing the fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB fulfilled efficient NADP+ regeneration and selective oxidation of various α,β-unsaturated alcohols to the corresponding α,β-unsaturated aldehydes. With the scope of redox enzymes, the fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB has become the latest successful example to improve catalytic performance in comparison with separated counterparts.

Background: α,β-unsaturated aldehydes are widely used in as organic synthesis of fine chemicals such as flavor, fragrances and pharmaceuticals. The selective oxidation of α,β-unsaturated alcohols to the corresponding α,β-unsaturated aldehydes remains challenging to overcome poor selectivity, over-oxidation and low atom efficiency in chemical routes.Results: An E. coli strain co-expressing NADP+-specific alcohol dehydrogenase YsADH and oxygen-dependent NADPH oxidase TkNOX was constructed, which enabled the NADP+ regeneration and catalyzed the oxidation of 100 mM 3-methyl-2-buten-1-ol to 3-methyl-2-butenal with the yield of 21.3%. The oxygen supply was strengthened by introducing the hemoglobin VsHGB into recombinant E. coli cells and replacing the atmosphere of the reactor with pure oxygen, which increased the yield up to 51.3%. To further improve catalytic performance, the E. coli cells expressing the multifunctional fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB was achieved, which totally converted 250 mM 3-methyl-2-buten-1-ol to 3-methyl-2-butenal after 8 h of whole-cell oxidation. The reaction conditions of the cascade biocatalysis were optimized, in which the supplement of 0.2 mM FAD and 0.4 NADP+ was essential for maintaining high catalytic activity. Finally, the established whole-cell system could serve as a platform for the synthesis of valuable α,β-unsaturated aldehydes from selective oxidation of various α,β-unsaturated aldehydes.Conclusions: The construction of the strain expressing the fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB fulfilled efficient NADP+ regeneration and selective oxidation of various α,β-unsaturated alcohols to the corresponding α,β-unsaturated aldehydes. With the scope of redox enzymes, the fusion enzyme YsADH-(GSG)-TkNOX-(GSG)-VsHGB has become the latest successful example to improve catalytic performance in comparison with separated counterparts.

Cipangopaludina chinensis which is a species of benthic macroinvertebrates was exposed to roxithromycin, and tested the erythromycin N-demethylase (ERND) of kidney, then explored the effect of roxithromycin on the biochemical indicator of C.chinensis. The results showed that roxithromycin had effect on the activity of ERND in the kidney of C.chinensis and the overall trend was promoting at the beginning then suppressing at the end, but the differences of the influence caused by different concentrations of roxithromycin was not obvious. In addition, it appeared from the survival condition of control group and experimental group, roxithromycin which is a kind of antibiotic, had no lethal effect on C.chinensis. But the concentration of roxithromycin which is more than 250 times, 500 times and 750 times of the environment used in this experiment had significant influence on the enzyme activity of the ERND in the kidney of C.chinensis.