Surfactant-assisted two phase partitioning bioreactors for laccase-catalyzed degradation of anthracene

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• 作者：A. Arca-Ramos ; G. Eibes ; ^{gemma.eibes@usc.es} ; M.T. Moreira ; G. Feijoo ; J.M. Lema
• 关键词：Two phase partitioning bioreactor (TPPB) ; Anthracene ; Laccase ; Mass transfer ; Surfactant
• 刊名：Process Biochemistry
• 出版年：2012
• 出版时间：July, 2012
• 年：2012
• 卷：47
• 期：7
• 页码：1115-1121
• 全文大小：491 K

文摘

The degradation of anthracene by laccase from Trametes versicolor in enzymatic reactors was evaluated. The use of a surfactant (Triton X-100) at concentration above critical micelle concentration (CMC) enhanced anthracene solubility and facilitated its degradation. Moreover, Triton exerted a beneficial effect on the laccase stability and protected it from the oxidative action of the mediator 1-hydroxybenzotriazole (HBT). In a further stage, the combined configuration of a two phase partitioning bioreactor (TPPB) operating with silicone oil as an immiscible solvent and the surfactant achieved the degradation of anthracene at higher conversion rate: 16 ¦Ìmol/L_Rh. Furthermore, a model for anthracene degradation by laccase-mediator system was developed. The first order kinetic constant (k) and the overall mass transfer coefficient (K_La) were estimated by using the method of least squares. The increased K_La value obtained, 788.1 h^?, proved that Triton also improved mass transfer. Anthracene concentration in aqueous phase was close to that corresponding to equilibrium state suggesting that mass transfer mechanism did not limit the global process. The kinetic constant, which is expected to depend on the initial concentration of enzyme, resulted in 52.2 h^?. Enzyme inactivation occurred in two stages and could be modeled by using a three parameter biexponential model. The possibility of reusing silicone oil to dissolve more anthracene was proven in three consequent cycles with high percentages of anthracene removal.