Amylase production by a Gram-positive bacterium isolated from fermenting tef (Eragrostis tef)
1994
Lealem, F. | Gashe, B.A.
Bacillus sp. A-001, which produced large amounts of amylase, was isolated from fermenting tef (Eragrostis tef) on tryptone soya agar supplemented with 1% starch. The organism grew between pH 4-5 and 10 5 with an optimum at 7-7.5. Growth occurred between 20 and 55 degrees C but the optimum was about 35-40 degrees C. At optimum medium pH (7.5) and a temperature of 35 degrees C the organism entered the stationary phase after about 72 h and amylase production was at its highest (9-6 units ml-1) at this time. Enzyme activity was optimal at pH 5-5 and 40 degrees C and showed good thermal stability; it required 110 min to lose 50% of its activity at 70 degrees C. The enzyme hydrolysed native starch (flour from tef, corn and kocho) to various oligosaccharides, including maltotriose, maltose and glucose.
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