International Science Community Association International Research Journal of Biological Sciences 2278 - 3202 2 2 2013 February 10 Thermostable Alkaline Serine Protease from Thermophilic Bacillus Species 29 33 EN Farzaneh Hosseini 1 Faculty of Bioscience, Department of Microbiology, Islamic Azad University, North Tehran Branch, Tehran, IRAN Adlgostar Afsoon 2 Faculty of Bioscience, Department of Biology, Islamic Azad University, North Tehran Branch, Tehran, IRAN Fariba Sharifnia 3 Panchal HetalK. 1 Dolat Usha Institute of Applied Sciences, Valsad; Veer Narmad South Gujarat University, Surat, Gujarat, INDIA Trivedi RatnaA. 2 Shree Ram Krishna Institute of Comp. Edu. and Applied Sciences; Veer Narmad South Gujarat University, Surat, Gujarat, INDIA Desai PratibhaB. 3 Venkata Saibabu 1 Dept. of Biochemistry, Center for Post Graduate Studies, Jain University, Jayanagar 3rd Block, Bangalore-560011, Karnataka, INDIA Francois NiyongaboNiyonzima 2 More SunilS. 3 Choubey K. 1 Deptt. of Zoology, G.V.Y.T. College, Durg, CG, INDIA Qureshi Y. 2 Deptt. of Zoology, Govt. College, Khertha, Distt. Balod, CG, INDIA Kulkarni D.A. 1 Department of Zoology, S.M.D.M. Mahavidyalyaya, Kallamb, Dist. Osmanabad, MS, INDIA Surwase S.S. 2 Department of Zoology, Rajaram College, Kolhapur, MS, INDIA NoorAzlina Ibrahim 1 Faculty of Agro Based Industry, Universiti Malaysia Kelantan (Jeli Campus), Locked Bag No. 100, 17600 Jeli, Kelantan, MALAYSIA Yusoff Norazila 2 > Research Paper 2012 11 14 2013 February 10 Screening and isolation of proteolytic bacteria were carried out from water samples of Lojing hot spring (Kelantan, Malaysia). Based on the qualitative screening on Skim Milk Agar (SMA), two isolates showed positive results by forming clearing zones around the colonies on SMA. The isolates were identified as Bacillus subtilis 50a and B. licheniformis 50b on the basis of the 16s rRNA gene sequencing. The effect of temperature, pH and inhibitors on enzymes activity and stability were investigated. The crude proteases for both isolates displayed maximal activity at 70\rC and showed characteristic pH optima at pH 9.0. Enzymes activities were totally inhibited by phenylmethyl sulphonyl fluoride (PMSF), suggested that the proteases from B. subtilis 50a and B. licheniformis 50b belong to the family of serine protease. The thermostability profile exhibited the protease from B. subtilis 50a was very stable at 50\rC (maintain 100% relative activity) and the protease activity retained 89% of its original activity after heat treatment at 60\rC for 30 min. Meanwhile, protease activity for B. licheniformis 50b retained 96 and 72% of the original activity after heat treatment at 50 and 60\rC, respectively. Considering their promising properties, B. subtilis 50a and B. licheniformis 50b could be a potential sources of enzymes for industrial applications. Copyright@ International Science Community Association