title: Production and biochemical characterization of a high maltotetraose (G4) producing amylase from Pseudomonas stutzeri AS22.
abstract: Amylase production and biochemical characterization of the crude enzyme preparation from Pseudomonas stutzeri AS22 were evaluated. The highest α-amylase production was achieved after 24 hours of incubation in a culture medium containing 10 g/L potato starch and 5 g/L yeast extract, with initial pH 8.0 at 30°C under continuous agitation at 200 rpm. The optimum temperature and pH for the crude α -amylase activity were 60°C and 8.0, respectively. The effect of different salts was evaluated and it was found that both α -amylase production and activity were Ca(2+)-dependent. The amylolytic preparation was found to catalyze exceptionally the formation of very high levels of maltotetraose from starch (98%, w/w) in the complete absence of glucose since the initial stages of starch hydrolysis (15 min) and hence would have a potential application in the manufacturing of maltotetraose syrups.
authors: Laboratoire de Génie Enzymatique et de Microbiologie, Ecole Nationale d'Ingénieurs de Sfax, BP 1173, 3038 Sfax, Tunisia.
authors: Hana
authors: H
authors: Maalej
authors: Laboratoire de Génie Enzymatique et de Microbiologie, Ecole Nationale d'Ingénieurs de Sfax, BP 1173, 3038 Sfax, Tunisia.
authors: Hanen
authors: H
authors: Ben Ayed
authors: Laboratoire de Génie Enzymatique et de Microbiologie, Ecole Nationale d'Ingénieurs de Sfax, BP 1173, 3038 Sfax, Tunisia.
authors: Olfa
authors: O
authors: Ghorbel-Bellaaj
authors: Laboratoire de Génie Enzymatique et de Microbiologie, Ecole Nationale d'Ingénieurs de Sfax, BP 1173, 3038 Sfax, Tunisia.
authors: Moncef
authors: M
authors: Nasri
authors: Laboratoire de Génie Enzymatique et de Microbiologie, Ecole Nationale d'Ingénieurs de Sfax, BP 1173, 3038 Sfax, Tunisia.
authors: Noomen
authors: N
authors: Hmidet
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification; D008320:Maltose / Q000031:analogs & derivatives* / Q000096:biosynthesis; D044223:Pseudomonas stutzeri / Q000201:enzymology* / Q000254:growth & development; D000520:alpha-Glucosidases / Q000096:biosynthesis / Q000737:chemistry / Q000302:isolation & purification
chemical_list: D001426:Bacterial Proteins; D008320:Maltose; C009819:maltotetraose; D000520:alpha-Glucosidases; C020135:glucan 1,4-maltotetraohydrolase