High yield production in seven days of Coriolopsis gallica 1184 laccase at 50 L scale; enzyme purification and molecular characterization

The optimization of culture conditions for high yield laccase production by white rot fungi has been extensively studied. However, to achieve short time laccase production remains a major challenge in several cases. The present study investigated an optimal process for production of Coriolopsis gallica 1184 laccase in a high yield of 200 900 Ul-1 in 7 d by 50 L scale submerged fermentation. Coriolopsis gallica 1184 laccase appeared as a robust enzyme against downstream process; only 13.5 % of laccase activity was lost at the end of downstream procedure. The pure enzyme appeared as a one-species laccase, with a molecular mass of 66 kDa as determined by SDS-PAGE. The pH optimum for 2,2'-azino-bis-[3-ethyltiazoline-6-sulfonate] oxidation ranged between 2.5 and 3.0 in 100 mM tartrate buffer. Optimum temperature for laccase activity was determined to be around 70 °C. The kinetic of laccase was investigated with four phenolic substrates. The lowest Km values (17 and 20 μM) were found for ABTS and guaiacol, respectively. Coriolopsis gallica 1184 laccase was characterized by mass spectrometry and shows that C. gallica 1184_LacI is very likely a new member of the AA1_1 subfamily. Our results clearly show high competitive potential of the robust extracellular C. gallica 1184 laccase to use it in different industrial processes.