Anaerobic environment as an efficient approach to improve the photostability of fatty acid photodecarboxylase

Fatty acid photodecarboxylase of Chlorella variabilis NC64A(CvFAP) is a novel photoenzyme with great potential in the treatment of waste lipids and production of sustainable aviation fuel. However, the fragile nature of Cv FAP to blue light is an urgent challenge. Herein, we demonstrated anaerobic environment could significantly improve the photostability of Cv FAP for the first time. The decarboxylation of palmitic acid by Cv FAP for 3 h under anaerobic environment increased pentadecane yield by 44.7% as compared to that under aerobic environment. The residual activity of Cv FAP after blue-light preillumination in the absence of palmitic acid for 0.5 h under anaerobic environment was 80.4%, which was 258.7 times higher than that under aerobic environment. Remarkable accumulation of superoxide radical and singlet oxygen in Cv FAP under aerobic environment led to the poor photostability of Cv FAP. Anaerobic environment helped to mitigate the production of superoxide radical and singlet oxygen in Cv FAP, improving the photostability of Cv FAP.

Effect of Oxygen and Bacteria on the Property of Polymer Gel

The viscosity property of Cr^3＋, Al^3＋, and compound ion cross-linked polymer gel solution in the anaerobic and aerobic environment was investigated aiming at meeting the practical demand of the oil field. The viscosity reserving effect after adding the biocide and the gelation in the anaerobic and aerobic environments was also studied in the paper. The results indicate that the viscosity of the cross-linked polymer gel solution caused by the water produced in aerobic environment is higher than that in anaerobic environment, and that the viscosity value of the cross-linked polymer gel solutions after adding biocides has improved to some extent and polymer gel has gelated well in anaerobic environment.