MODIFIKASI ISOLASI DAN IDENTIFIKASI β-AMILASE DARI UBI CILEMBU (Ipomoea batatas cv. Cilembu) SKRIPSI YULI LESTARI NIM 10505002 PROGRAM STUDI KIMIA FAKULTAS MATEMATIKA DAN ILMU PENGETAHUAN ALAM INSTITUT TEKNOLOGI BANDUNG 2009 MODIFIKASI ISOLASI DAN IDENTIFIKASI β-AMILASE DARI UBI CILEMBU (Ipomoea batatas cv. Cilembu) (MODIFICATION OF ISOLATION AND IDENTIFICATION OF β –AMILASE FROM CILEMBU SWEET POTATOES (Ipomoea batatas cv. Cilembu) ) SKRIPSI YULI LESTARI NIM 10505002 PROGRAM STUDI KIMIA FAKULTAS MATEMATIKA DAN ILMU PENGETAHUAN ALAM INSTITUT TEKNOLOGI BANDUNG 2009 ii ABSTRACT Cilembu, a place in Sumedang – West Java is well known of its crop which is named Cilembu sweet potato. Cilembu sweet potato has a unique character compared with other kinds of potato. It has sweet taste which makes this kind of potato is high qualities potato than the others in Indonesia. As potato is one of carbohydrate source, it has β-amylase. In this research, amylase was isolated at temperature of 40°C in 0.016 M buffer Na-acetate pH 4.8. It is hoped that by using an addition of excessive starch substrates bind to all the enzymes so that of enzyme isolation required a short time period. Enzyme extract is fraccinated by using ammonium sulfate 0 – 60 % and 60 – 80 %. The activity test was done by using Somogyi – Nelson method while is determine protein concentration was determined by using Bradford method. Based on those methods, specific activity of crude enzyme extract has risen two times after the addition of excessive substrate in which it has the value 33.369 mg sugar.mg protein -1 .menit -1 . The highest specific activity is shown on 60 – 80% fraksi, with the value as 41.562 mg sugar.mg protein -1 .menit -1 . While the yield is 1.39%, it is higher than the research before which has 0.89%. The identification of β-amylase is done by Native PAGE, Reserve Zymography, SDS PAGE, and TLC. Based on TLC identification, the product resulted is Maltosa and the molecule weight as 150 kDa. It means that the enzyme isolation resulted β-amylase. Keywords : β-amylase, Cilembu sweet potatoes, Native PAGE, Reverse Zymography, TLC. iii ABSTRAK Ubi Cilembu yang berasal dari daerah Cilembu, Sumedang, Jawa Barat, adalah salah satu jenis ubi yang memiliki karakteristik yang berbeda. Rasanya yang manis, menjadikan ubi ini lebih unggul dibandingkan dengan ubi lainya di Indonesia.