Karakterisasi a-amilase bacillus firmus KH.9.4 Alkanotoleran dari limbah cair tapioka

Abstract

Alkalotolerant bacteria identifeid as Bacillus firmus KH. 9.4 was isolated from tapioca liquid waste from Kedung Halang, Bogor. The isolate showed optimum α-amylase activity after 15 hours of cultivation on liquid media. Optimum enzyme activity occured at PH 6.0 and temperature 80°C. Upon heat treatment at PH 6.0 and 80°C the enzyme was still 100% active after 6 hours Incubation without substrate. The enzyme activity was enhanced by supplement 10 mM MgSO[4]7H[2]O. The presence of 1,5, and 10mM ethylenediaminetetraacetic acid demonstrated the inhibitory effect to this enzyme. Zymogram analysis revealed one translucent zone corresponding to soluble strach activities after 60 minutes of incubation at 40°C in the 0.05 M phosphate buffer pH 7.0. Whereas SDS-PAGE analysis showed that there are 5 bands of proteins.