Monday, April 29, 2013
Exhibit Hall
Filamentous fungi are known for their outstanding ability of producing enzymes, particularly those for lignocellulosic substrates degradation. Endophytic fungi are potential producers of these enzymes and are present within plant tissues. Since endophytic fungi colonize plant tissues, their enzymes should provide interesting characteristics from the standpoint of attack to the plant cell wall components. In this context, the endophytic filamentous fungus named AM 01, isolated from Alibertia macrophylla, was used in this work for the production of cellulases (endoglucanase and β-glucosidase) and xylanase by solid-state fermentation (SSF), in mixture (5g) of cottonseed meal and wheat bran (1:1 w/w) as substrates, at 28oC. The influences of cultivation time, amount of inoculum and initial substrate moisture were evaluated. The peaks of endoglucanase (251.12 U/g), β-glucosidase (52.38 U/g) and xylanase (187.17 U/g) production occurred at 192h and the cultivation time was fixed at this value for the next experiments. The influence of inoculum amount was evaluated using 3, 6, 9 or 12 mycelial disks of 8.0 mm diameter and the highest endoglucanase, b-glucosidase and xylanase productions (249,02, 53,10 and 141,55 U/g, respectively) were obtained using 6 mycelial disks. Then, the influence of substrate initial moisture was evaluated ranging from 60-80%. Initial moistures from 60 to 65% provided the highest enzymes productions (207,69, 72,91 and 131,33 U/g for endoglucanase, b-glucosidase and xylanase, respectively).