A salt, detergent, and solvent tolerant protease from <i>Bacillus</i> sp. B001: Low-cost, easy-purified, and enhanced production by raw material based culture strategy

Abstract

To enhance the protease production and decrease cost, corn flour and soy peptone were screened as cheap raw materials for the production of extracellular proteases by Bacillus strains. Their compositions in the medium suitable for enzyme production of Bacillus sp. B001 were optimized using statistical experiment designs. Under the optimized conditions, the protease production of Bacillus sp. B001 was stable at the stationary stage and reached to 63,200 U/mL, approximately 1.84-fold increase compared with that using the original medium. These improvements could be attributed to the release of the catabolite repression by crude materials corn flour and soy peptone which contained low level of available nutrients. Additionally, a highly pure protease which displayed excellent stability and compatibility with high salinity, commercial laundry detergents, and organic solvents, was rapidly obtained by two-step procedure involving ammonium sulphate precipitation and anion exchange from the fermentation cultures of B001 in the optimized medium. When the culture method applied to other Bacillus strains, their protease yields were all remarkably increased approximately 2.9 to 8.5 folds. In conclusion, a low-cost, easy-purified, and effective producing strategy using the cheap raw materials was developed here, representing a potential application for protease production in various Industrial processes.

Determination of peptidase production potential of Bacillus strains isolated from ropey bread and optimisation of some culture conditions for peptidase production

“…Her bir organizma ya da suşun gelişimi ve ürün üretimi için fizikokimyasal ve besinsel ihtiyacı farklı olabileceğinden [44] her bir çalışmada, kullanılan suşlar açısından C/N oranının da belirlenmesi ürün üretiminde en iyiye ulaşmak açısından fayda sağlamaktadır. Nitekim Beg vd [45] Bacillus mojavensis ile alkali peptidaz üretimi gerçekleştirdikleri bir çalışmada 2 mg/ml glukoza karşılık 12 mg/ml kazamino asit kullanımının en iyi C/N oranı olduğunu, Wu vd [46] ise Bacillus sp. B001 suşuyla peptidaz üretiminin optimizasyonunu yaptıkları çalışmada karbon ve azot kaynakları olarak 19.6 g/l mısır unu ile 6.2 g/l soya peptonu kullanımının ideal olduğunu tespit etmişlerdir.…”