Direct evolution of an alkaline fungal laccase to degrade tetracyclines.
Int J Biol Macromol
; 277(Pt 4): 134534, 2024 Oct.
Article
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| MEDLINE
| ID: mdl-39111464
ABSTRACT
A fungal laccase-mediator system capable of high effectively oxidizing tetracyclines under a wide pH range will benefit environmental protection. This study reported a directed evolution of a laccase PIE5 to improve its performance on tetracyclines oxidization at alkaline conditions. Two mutants, namely MutA (D229N/A244V) and MutB (N123A/D229N/A244V) were obtained. Although they shared a similar optimum pH and temperature as PIE5, the two mutants displayed approximately 2- and 5-fold higher specific activity toward the mediators ABTS and guaiacol at pHs 4.0 to 6.5, respectively. Simultaneously, their catalytic efficiency increased by 8.0- and 6.4-fold compared to PIE5. At a pH range of 5-8 and 28 °C, MutA or MutB at a final concentration of 2.5 U·mL-1 degraded 77 % and 81 % of 100 mg·L-1 tetracycline within 10 min, higher than PIE5 (45 %). Furthermore, 0.1 U·mL-1 MutA or MutB completely degraded 100 mg·L-1 chlortetracycline within 6 min in the presence of 0.1 mM ABTS. At pH 8.0, MutA degraded tetracycline and chlortetracycline following the routine pathways were reported previously based on LC-MS analysis.
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Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Tetraciclinas
/
Lacasa
Idioma:
En
Revista:
Int J Biol Macromol
Año:
2024
Tipo del documento:
Article
País de afiliación:
China