In order to obtain high amounts of α-amylase enzyme from Bacillus bacteria a new medium was developed. In this medium, three strains of Bacillus bacteria were grown in the presence of different carbon, nitrogen and metal ions. | Turk J Biol 24 (2000) 299–308 © TÜBİTAK Increase of the α-amylase yield by Some Bacillus Strains* Elif SARIKAYA Ankara University, Faculty of Science, Biology Department, Ankara-TURKEY Velittin GÜRGÜN Ankara University, Faculty of Agriculture, Food Engineering Department, Ankara-TURKEY Received: Abstract: In order to obtain high amounts of α-amylase enzyme from Bacillus bacteria a new medium was developed. In this medium, three strains of Bacillus bacteria were grown in the presence of different carbon, nitrogen and metal ions. The highest α-amylase yield was obtained by addition of Nacitrate, strach and sucrose for the strains of B. subtilis, B. amyloliquefaciens I and B. amyloliquefaciens II, respectively. As a nitrogen source, yeast extract was found to be effective on enzyme yield for B. subtilis and B. amyloliquefaciens II, while ammonium sulfate was found to be effective for B. amyloliquefaciens I. None of the metal ions increased the enzyme activity of all the strains. However, a slight increase was determined by increase of oxygen concentration. The optimum temperature of each bacteria for α-amylase was 55°C. The optimum pH of the B. subtilis enzyme was , while for both strains of B. amyloliquefaciens the optimum pH was . Enzymes were not stable at elevated temperatures and at low or high pH values. Inhibitory effects of Ag, Zn and Cu were observed in all Bacillus strains. Maltose and a small amount of glucose were determined as the split products of starch by thin layer chromatography (TLC) after incubation of starch with amylases of all the strains used in this study. Key Words: Bacillus, α-amylase, production, characterization, thin layer chromatography. Bazı Bacillus Suşlarında α-amilaz Veriminin Arttırılması Özet: Bacillis suşlarından α-amilaz enziminin yüksek verimde elde etmek için yeni bir ortam geliştirildi. Bu ortamda üç Bacillus suşu farklı karbon, azot ve metal kaynakları varlığında üretildi. En yüksek alfaamilaz verimi B.
