Pakistan Journal of Biological Sciences1028-88801812-5735Asian Network for Scientific Information10.3923/pjbs.2006.1328.1332Streptomyces clavifer]]>HoqueMd. MahfuzulKhanamMahmuda ShiekhMd. ArifNaharNurun KhanMahbubar RahmanKhanZahed U.M.7200697Amongst seventeen previously identified Streptomyces species, S. crystallinus, S. noboritoensis, S. anulatus and S. clavifer were selected for α-amylase activity. All these species were grown in fermentation broth for α-amylase production in orbital shaker under optimum conditions. The fermentation broth cultures were then centrifuged at refrigeration temperature at 1000 rpm and supernatants were collected. The α-amylase from each supernatant was extracted by ammonium sulfate precipitation at 90% saturation and was dialyzed. The enzyme was assayed under standard assay conditions. Streptomyces clavifer was found to have the highest α-amylase activity amongst others. The effect of pH and temperature on α-amylase activity of Streptomyces clavifer was determined. The optimum pH and temperature for enzyme activity was found be 7.0 and 45°C, respectively. The enzyme was found stable at pH 6.0 to 8.0 and temperature upto 55°C. The kinetics of the enzyme was determined under standard conditions. The KM and the Vmax of the enzyme were determined as 4 mg and 0.03 mg sec-1, respectively. α-amylase together with other amylolytic enzymes have tremendous applications in textile industries, confectioneries, pharmaceutical industries and other food industries as hydrolyzing bioagents.]]>Fogarty, W.M.,19831983pp: 1-92pp: 1-92Gottlieh, D.,19731973pp: 1-9pp: 1-9Hoque, M.M., T. Ohashi, Y. Kimur, S. Nakajima, K. Nagamine and E. Higashie,1997Streptomyces hygroscopicus subsp.]]>2712Hoque, M.M., Y. Kimur and E. Higashie,1999Streptomyces Strain GT-32).]]>1253261Hoque, M.M., M.U. Ahmed, N. Nahar, M.R. Khan and Zahed, U.M. Khan,2001Streptomyces rochei Berger, Jampolsky and Goldberg.]]>30125129Hoque, M.M., R. Noor, N. Nurun, M.R. Khan and Z.U.M. Khan,2003Streptomyces roseolus isolatd from Bangladesh soil.]]>203135Hoque, M.M., S. Akter, M.U. Ahmed, N. Nurun, M.R. Khan and Z.U.M. Khan,2003Streptomyces misakiensis activity.]]>32199225Hoque, M.M., M.A. Sheikh, M. Khanam, N. Nahar, M.R. Khan and Z.U.M. Khan,2005Streptomyces griseoloalbus and some factors influcing the enzyme activity.]]>227678Iwasa, T., H. Yamamoto and M. Shibata,1970Streptomyces hygroscopicus var. limoneus Nov. var., validamycin producing organism.]]>12596602Miller, G.L.,195931426428Shirling, E.B. and D. Gottlieb,1966Streptomyces species.]]>16313340Takashaki, Y., A. Hayashi, Y. Ino, T. Ogawa, S. Hayashi and K. Lima,1993Streptomyces species. No.-27.]]>57477478Teresita, M.E., D.T. Richard and B.E. Francisco,199619669677Waksman, S.A. and A.T. Henrici,1948Streptomycetaceae Waksman and Henrci.]]>1948pp: 929-980pp: 929-980Williams, S.T., M.E. Sharpe, and J.G. Holt,19899th Edn., Vol. 4,pp: 2450-2493pp: 2450-2493