An amylase that hydrolyzes starch into maltopentaose as a main product was found in the culture supernatant of a strain of Bacillus megaterium KSM B-404 isolated from local soil. The enzyme was purified 129-fold by ammonium sulfate precipitation, DEAE-Toyopearl and Superdex 75 HR 10/30 column using a FPLC system. The molecular weight of the amylase was determined as about 68 kDa by using SDS-PAGE. Optimum pH and temperature of amylase were found to be 50°C and pH 6.0∼7.0, respectively. The enzyme was stable up to 60°C by addition of Ca2+ and its pH stability was in the range of 6.0∼10.0. The activity of enzyme was inhibited by Cu2+, Hg 2+, and Fe3+ and maintained by Ca2+ and Mg 2+. EDTA and pCMB also showed inhibitory effect to the enzyme. TLC and HPLC analysis of the products of the enzyme reaction showed the presence of maltopentaose (52%), maltotriose (25%), maltose (11%), glucose, and maltotetraose in the starch hydrolysates.
|Number of pages||7|
|Journal||Korean Journal of Microbiology and Biotechnology|
|Publication status||Published - 2002 Dec|
- Bacillus megaterium KSM B-404
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology