Production of Glucoamylases by A Rotting Cassava Tuber Fungus on Solid Culture

บทคัดย่อ

Aspergillus niger H-9 is a fungal strain isolated from rotting cassava tuber in Thailand. In the present study, the strain was found to produce better glucoamylase on solid culture for 3-4 days. (ricebran and soybean meal in the ratio of 9:1). The moisture content for cultivation was found to be 3:1 of solid-liquid ratio. The suitable initial pH and temperature were 5-6 and 30 ^oC. The highest enzyme yield was found to be 1,080 units. Optinum pH of the enzyme for starch hydrolysis was at pH 5.5. Such enzyme shows pH stability between 4-8, temperature activity at 60-70 ^oC and temperature stability between 30-70 ^oC.