Laccase concentration by foam fractionation of Cerrena unicolor and Pleurotus sapidus culture supernatants

Abstract

Foam fractionation process for concentration of laccases from two Basidiomycete strains under different process conditions was investigated. Culture supernatants of Cerrena unicolor and Pleurotus sapidus containing active laccase were used with and without surfactant additives. Two surfactants: cationic cetrimonium bromide (CTAB) and non-ionic Polysorbate 80 were applied in the range from 0.2 mM to 1.5 mM. The pH levels ranging from 3 to 10 were examined with particular attention to pH=4, which is close to the pI of the enzymes. Results show that the source of the enzyme is significant in terms of partitioning efficiency in a foam fractionation process. Laccase from Cerrena unicolor showed the best activity partitioning coefficients between foamate and retentate of almost 200 with yields reaching 50% for pH 7.5 and concentration of CTAB c CTAB = 0.5 mM, whereas laccase from Pleurotus sapidus showed partitioning coefficients of up to 8 with 25% yield for pH 4 and c CTAB = 0.5 mM.

Comparison of downstream processing methods in purification of highly active laccase

“…As the second purification method, foam fractionation was performed under the earlier determined conditions [25]. The results concerning the phase volume, laccase activity and protein content, as well as the calculated activity yields and purification folds are presented in Table 2.…”

“…1) consisted of a glass column of 62 cm in length and inner diameter of 3 cm, a foam collector, a Büchner flask connected to a pump producing low under pressure, a compressed air distributor equipped with a reducing valve set to 2 bar and an electronic valve for flux control.

Fig. 1Foam fractionation equipment setupReproduced from Blatkiewicz et al [25] with permission granted from Chemical & Process Engineering, De Gruyter

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“…Reproduced from Blatkiewicz et al [25] with permission granted from Chemical & Process Engineering, De Gruyter…”

“…They report recoveries up to 70.2% with the feed positioned at the top of the column. Our group focused mainly on laccase isolated from Cerrena unicolor and determined that the best activity partitioning coefficients between foamate and retentate was almost 200 with the yield reaching 50% for pH 7.5 and the concentration of cationic surfactant cetrimonium bromide (CTAB) equal to 0.5 mM [25]. Moreover, it was proved that the source of the enzyme is important in terms of partitioning efficiency, as markedly different experimental results were obtained for laccases derived from two distinct fungal species, namely C. unicolor and Pleurotus sapidus [25].…”

Foam fractionation for enhancing silica gel adsorption of urokinase from human urine

“…From Table , UK could be effectively enriched by foam fractionation so that the foamate has a higher UK concentration than fresh urine. Furthermore, the decrease in superficial air flow rate reduced the liquid holdup in foam and whereby increased both activity concentration and specific activity of UK in the foamate . In physical adsorption, the adsorption rate and the balanced adsorption concentration often increased as the concentration of targeted compound rose .…”