Perubahan Karakter Protease Isolat CG-10 yang Diimobilisasi dengan Bentonit
ABSTRACT: The CG-10 isolate is
a thermophile microorganism live in extreme environments, a hot spring located
at Cangar East Java, having temperature 50 oC. The isolate had following
characteristics: rod shaped cells, gram-positive, size of cells 6-14 µm,
aerobic, and obligate thermophile. Based on the nucleotide sequences of its
16S-rRNA gene indicated that these isolate was closely related to Bacillus
caldoxylolyticus (98.305% sequence similarity). The enzymes produced by
thermophile microorganism were usually active at a higher temperature than that
of the environment in which they live. Therefore it is possible to use this
enzyme in industries requiring high temperature in their production processes.
The CG-10 isolate grew well in a liquid waste of tofu and could secretion
extracellular protease. The protease was isolated by fractioning at 35% (w/v)
ammonium sulfate, centrifuged at 4000 rpm for 15 minutes, and had the following
characteristics: optimum temperature 80 oC, optimum pH 8, the molecular weight
53.000-76.000 Dalton (for the protease showing the highest activity), pHI value
between 7.5 up to 8.2, and could be classified as a serine alkaline protease.
For increasing the efficiency of this protease in industries had been done by
immobilization with bentonite. The immobilization process is done at optimum pH
(pH 5). The characteristic changes research of protease CG-10 isolate
immobilized by bentonite had been done. The immobile enzyme showed different
characteristics for that of the native (mobile enzymes). The immobile enzyme
showed a different optimum temperature, a higher heat resistance but the same
optimum pH as the native enzyme.
Penulis: Rudiana Agustini
Kode Jurnal: jpkimiadd050029
