Author/Editor     Vukelić, B; Ritonja, A; Renko, M; Pokorny, M; Vitale, L
Title     Extracellular alpha-amylase from Streptomyces rimosus
Type     članek
Source     Applied microbiology and biotechnology
Vol. and No.     Letnik 37
Publication year     1992
Volume     str. 202-4
Language     eng
Abstract     A purification procedure for an extracellular alfa-amylase from streptomyces rimosus, oxytetracycline-producing strain, is described. The enzyme obtained was shown to be an acidic (pI 4.75) monomer with a relative molecular mass (Mr) of 43000, containing three cysteines involved in the catalytic activity of the enzyme. Its amino-terminal part has 57-67 percent homology with amylases from other Streptomyces species. S. rimosus alfa-amylase is sensitive to higher temperatures, and partially stabilized by Ca2+ ions. It hydrolyses starch (optimum at pH 5.0-6.0) in an endohydrolase manner giving rise to maltotriose, maltoteatrose and higher oligosaccharides. Starch grannules, except those from rice, were not significantly affected by the isolated alfa-amylase.
Descriptors     STREPTOMYCES
ALPHA-AMYLASE
SPECTROPHOTOMETRY
CHROMATOGRAPHY, GEL
SEQUENCE ANALYSIS