title: Production of amylase by newly isolated moderate halophile, Halobacillus sp. strain MA-2.
abstract: Production of extracellular amylase was demonstrated under stress conditions of high temperature and high salinity in aerobically cultivated culture of a newly isolated moderately halophilic bacterium of spore-forming Halobacillus sp. strain MA-2 in medium containing starch, peptone, beef extract, and NaCl. The maximum amylase production was secreted in the presence of 15% (w/v) Na(2)SO(4) (3.2 U ml(-1)). The isolate was capable of producing amylase in the presence of NaCl, NaCH(3)COOH, or KCl, with the results NaCl>NaCH(3)COOH>KCl. Maximum amylase activity was exhibited in the medium containing 5% (w/v) NaCl (2.4 U ml(-1)). Various carbon sources induced enzyme production. The potential of different carbohydrates in the amylase production was in the order: dextrin>starch>maltose>lactose>glucose>sucrose. In the presence of sodium arsenate (100 mM), maximum production of the enzyme was observed at 3.0 U ml(-1). Copper sulfate (0.1 mM) decreased the amylase production considerately, while lead nitrate had no significant enhancement on amylase production (p<0.05). The pH, temperature, and aeration optima for enzyme production were 7.8, 30 degrees C, and 200 rpm, respectively, while the optimum pH and temperature for enzyme activity was 7.5-8.5 and 50 degrees C, respectively.
authors.affiliation: Department of Biology (Microbiology Unit), Faculty of Science, University of Tehran, Iran.
authors.forename: M A
authors.initials: MA
authors.lastname: Amoozegar
authors.forename: F
authors.initials: F
authors.lastname: Malekzadeh
authors.forename: Khursheed A
authors.initials: KA
authors.lastname: Malik
mesh_terms: D000681:Amylases / Q000032:analysis / Q000096:biosynthesis* / Q000378:metabolism; D001406:Bacillaceae / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D003470:Culture Media; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D019216:Metals, Heavy / Q000378:metabolism / Q000633:toxicity; D013213:Starch / Q000378:metabolism; D013696:Temperature
chemical_list: D003470:Culture Media; D019216:Metals, Heavy; D002244:Carbon; D013213:Starch; D000681:Amylases