Isolation of protease producing novel Bacillus cereus and detection of optimal conditions

Kebabcı Ö.

African Journal Of Biotechnology, cilt.10, sa.7, ss.1160-1164, 2011 (SCI Expanded İndekslerine Giren Dergi)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 10 Konu: 7
  • Basım Tarihi: 2011
  • Dergi Adı: African Journal Of Biotechnology
  • Sayfa Sayıları: ss.1160-1164


Fifteen bacterium strains were isolated from soil samples and the one that had the highest proteolytic
activity, from Susanolu village at Silifke-Mersin, was selected. The strain was identified and
determined as Bacillus cereus. The bacterium, that had R type colony morphology, subterminal spores,
motile and facultative anaerobe microorganism, was a gram positive with 10 m length and 1 m width. It
could ferment glucose, fructose and maltose which formed acid but not gas. Catalase and urease were
positive. The bacterium could grow on common medium easily and form b-haemolyze on blood agar. It
was determined that the microorganism’s growth continued up to the 12th hour and when it gets to the
18th hour, it was in a stationary phase. As a result, after the 18th hour, it was in a lytic phase. The
optimum growth temperature range was 20 - 40°C and the optimum pH range was 6.0 – 10.0,
respectively. Maximum growth was obtained at 30°C and at pH 7.0. The highest protease activity was
determined at 30°C temperature and 6.4 pH conditions and after the 18th hour, it decreased evidently.