Optimization of culture conditions for alkaline protease production from waste breads using Bacillus subtilis

Ozdenefe M. S. , DİNÇER S. , ÜNAL M. Ü. , Kayis F. B. , Takci H. A. M. , Arkut A.

ROMANIAN BIOTECHNOLOGICAL LETTERS, cilt.22, sa.3, ss.12597-12610, 2017 (SCI İndekslerine Giren Dergi) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 22 Konu: 3
  • Basım Tarihi: 2017
  • Sayfa Sayıları: ss.12597-12610


An alkaline protease-producing microorganism was isolated from a soil sample which is collected from Cukurova University campus and identified as a strain of Bacillus subtilis. The culture conditions were optimized for maximum enzyme production. Optimum enzyme production was achieved from fermentation medium which includes 1% waste bread and 1% casein powder as carbon and nitrogen source at pH 10.5 and 37 degrees C for 72 h incubation period with agitation of 200 rpm. The optimum inoculum amount and inoculum age were found as 5% and 4 hrs, respectively. Enzyme production reached its maximum value when a baffled Erlenmeyer flask with cotton was used. The approximately 20-fold increase in alkaline protease production was observed as a result of culture medium optimization. Substantial increase in alkaline protease activity was detected in optimized medium (134.64 U/mL) when compared with unoptimized medium (6.45 U/mL). It has been concluded that screening of suitable medium components has asignificant role in the production of alkaline protease by B. subtilis.