ABSTRACT
ABSTRACT The aim of this study is the production, purification, and characterisation of thermostable raw starch hydrolyzing α-amylase produced by Bacillus mojavensis SO-10. The maximum production conditions of α-amylase were found at 36th hour, 35 °C and pH 7.0. We utilized three steps to purify the thermostable α-amylase and as a result, 34-fold and 18% yield were obtained. The molecular weight of purified α-amylase was determined as 73 kD. The Km and Vmax rates were detected as 0.010 mM and 3.38 µmol min−1, respectively. This purified α-amylase exhibited the highest activity at pH 5.0-6.0 and 70 ºC and showed stability over a wide variety of pH and temperature at 4.0-8.0, and 40-50 ºC, respectively. The thermostable purified α-amylase exhibited stability in the presence of denaturing agents and heavy metal ions. The purified enzyme hydrolyzed the raw starches of corn and wheat grains in the ratio of 36.7% and 39.2% respectively. The end-yields of soluble starch hydrolysis were analyzed by thin-layer chromatography (TLC). In addition, the usage of purified α-amylase in clarification of apple juice and domestic washing detergent industries were evaluated.
ABSTRACT
This study reports the action of digestive juice of snail Limicalaria flammea on raw starches. This juice exhibited maximum activity at pH 4.0-5.5 and was optimally active at 40-50 °C. About 82.5 % of the original amylasic activity still remained after treatment at 50 °C for 16 h. The digestive juice had a strong digesting ability towards various raw starches and efficiently hydrolyzed raw corn starch at a concentration of 1.0% and pH 5 at 40 °C in a period of 12 h. The rate of hydrolysis of the raw corn and cassava starches were 64.37 % and 42.0 % respectively while that of palmyrah palm was 29.05 %. The analysis of the hydrolyzed products of the raw starches by thin layer chromatography showed the glucose, maltosaccharide and dextrin after 12 h of hydrolysis.
ABSTRACT
strains that could produce raw starch-digesting glucoamylase were isolated from soil and mildewed rice.The highest raw starch-digesting glucoamylase activity strain named OR-1 was identified as Rhizopus.sp.The raw starch-digesting glucoamylase activity of the strain is 90U/mL.Through UV and NTG mutagenesis,the raw starch-digesting glucoamylase activity raised to 200U/mL and 325U/mL respectively.The RDA were 70% and 65% respectively.