Physico-Chemical Characteristics of Crude Cellulases and Xylanases Produced by Two Endophytic Fungi Botryosphaeria sp. AM01 And Saccharicola sp. EJC04

The interest in endophytic fungi has increased over the years and since they colonize plant tissues their enzymes should have interesting characteristics from the standpoint of attack to the plant cell wall components. So, it is important to evaluate their physico- chemical and biochemical characteristics. In this context, crude cellulases and xylanases produced by two endophytic fungi, Botryosphaeria sp. AM01 and Saccharicola sp. EJC04, by SSF were used in this work. The optimal pH and temperature of activity were between 4.5–6.0 and between 60-75 °C, respectively. The enzymes were stable over a wide pH range and in relation to the influence of temperature on the stability, stood out the β-glucosidase from Saccharicola sp. EJC04 (70% of activity at 70 °C) and the β-xylosidase from Botryosphaeria sp. AM01 (90% of activity at 75 °C).
The β-glucosidase and β-xylosidase from both isolates retained about 75-80% of their activity in the presence of glucose or xylose, respectively, at 6 mmol/L. Ethanol stimulated the activity of the β-glucosidase from Botryosphaeria sp. AM01 (approximately 60% higher at ethanol 15%) and the enzyme of Saccharicola sp. EJC 04 showed a reduction on its activity at concentrations of ethanol above 15%. The β-xylosidase from Botryosphaeria sp. AM01 retained approximately 60% of activity in the presence of ethanol at 5%. On the other hand, the activity of β-xylosidase produced by Saccharicola sp. EJC04 was increased in the presence of 5-10% of ethanol, retaining about 100% of activity when the alcohol was used at a concentration of 20%.