Mycobiota Associated with Sugarcane Bagasse in Upper Egypt and Their Xylanolytic Activity

Sugarcane bagasse is one of the major agrowastes in Upper Egypt. In this study, 150 sugarcane bagasse samples were collected from five sugarcane factories in Upper Egypt. The mycobiota associated with each sample was isolated and identified using the dilution-plate technique on glucose Czapek's agar medium. Aspergillus was the most dominant genus and was recovered from approximately 92.67% of the samples, contributing 40.63% of the total fungi in all samples. Followed by Penicillium species, recovered from 77.3% of the samples, contributing 23.02% of the total fungi. Seventy-three fungal isolates were screened for their xylanolytic activity at 30˚C and 10˚C in both solid and broth cultures. Fifty-five isolates were xylanase producers (14 high, 32 moderates, and 9 low producers) at 10 ˚C. In contrast, at 30 °C, only 52 isolates showed positive xylanolytic activity, with diameters ranging from 12 to 30 mm. Based on the primary screening, the most active producers were assayed for xylanase production at 10 ˚C and 30 ˚C spectrophotometrically using dinitrosalicylic acid (DNS) reagents. The highest activity (4.93 ± 0.74 mg/ml) and (8.84 ± 1.12) were produced by Syncephalastrum racemosum and P. funiculoseum at 10 °C and 30 °C, respectively