Optimized production, purification and partial characterization of two thermostable Laccases from a Pycnoporus Sanguineus strain
(2012) Oxizymes 2012 — Location: Marseille, France (16.September.2012)
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- Authors
Agathos, Spiros N. 
- et. al.
- Abstract
- Thermostability is crucial for an efficient application of laccases in industrial processes. In this study, two thermostable laccase isoforms were characterized, one of them amongst the most thermostable laccases described so far. Their production from the Pycnoporus sanguineus strain CS43 isolated in Mexico was improved through optimization of medium composition and inducer / co-inducer concentrations. The best conditions from a screening experiment in shaken flasks were integrated in an experimental design. To the best of our knowledge, this work reports the highest laccase levels for Pycnoporus sanguineus achieving up to 140,000 U/L (ABTS, pH 3.0) in a 10 L stirred tank reactor. Under the applied culture conditions, this strain produced several isoforms. The two abundant isoforms (Lac II and Lac III) were purified by ultrafiltration, anion exchange and hydrophobic interaction chromatography. Partial sequencing of the proteins by tryptic digestion and MALDI/TOF MS/MS suggests the existence of different genes for Lac II and Lac III. Their apparent molecular weight (determined by SDS-PAGE) is 68 kDa for Lac II and 66 kDa for Lac III. At 60 °C, the half-life of Lac II is 9 times higher (18 h) than Lac III (2 h). Degradation of several endocrine disrupting chemicals and pharmaceutical contaminants was shown with laccase-containing culture supernatant as well as with the purified isoforms. The two isoforms showed a remarkable difference in their ability to oxidize diclofenac. After 2 hours of reaction, Lac II and Lac III had removed 67% and 40% diclofenac, respectively. The degradation of bisphenol A (BPA) was better with the non-purified culture supernatant (90 %) than with both purified enzymes (60 %).
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Ramirez Cavazos, L. I., Nair, R., Enaud, E., Demarche, P., Agathos, S. N., & et al. (2012). Optimized production, purification and partial characterization of two thermostable Laccases from a Pycnoporus Sanguineus strain. Oxizymes 2012, Marseille, France. https://hdl.handle.net/2078.5/249141