Characterization of cellulolytic activities of Bjerkandera adusta and Pycnoporus sanguineus on solid wheat straw medium
Rosa E. Quiroz-Castañeda
Claudia Martínez Anaya*
Financial support: CONACYT grant 48256Z and Conacyt scholarships to Rosa E. Quiroz-Castañeda (No. 47895) and Edgar Balcázar-López (No. 204223); and a postdoctoral fellowship to Claudia Martínez-Anaya (Exp. No.050272).
Keywords: B. adusta, cellulases, P. sanguineus, wheat straw, xylanases.
Cellulolytic properties of two white rot fungi, Bjerkandera adusta and Pycnoporus sanguineus, cultivated on wheat straw agar medium, were characterized and compared. Optimal growing parameters for maximum enzyme production for both fungi were wheat straw medium pH 5 and 28ºC. B. adusta showed, on the 6th day of culture, carboxymethylcellulose (CMC)ase activity levels 1.6 times higher than maximal P. sanguineus activity, achieved on the 8th day. B. adusta supernatants also displayed higher activity levels towards xylan (3.6-fold) compared to those of P. sanguineus. However, enzymes from P. sanguineus were more robust resisting one hour incubation at high temperatures (up to 80ºC), and exhibiting activity and stability in pH range from 2 to 8. Cellulolytic activities, with molecular masses ranging from 25 to 90 kDa, from the two species were detected in zymograms.