Abstract

Optimization of Growth Conditions for Levansucrase Production by Bacillus licheniformis in Solid State Fermentation

Author(s): Imen Dahech, Rania Bredai and Karima Srih

Solid state fermentation processes involve the growth of microorganisms on a solid material in the absence or near absence of free-flowing water. Hence, the objective of the present study was the optimization of medium composition and cultural conditions for levansucrase enzyme production by Bacillus licheniformis under solid state fermentation using cheaper sources as agricultural residues. The enzyme production was affected by incubation periods, level of moisture content and carbon source supplementation. Maximum enzyme production of about 62.68 U/g of levansucrase was obtained under optimum conditions with an incubation period of 48 h, initial moisture content of 80% and in the presence of waste dates (6g) at 40ºC. The extraction of enzyme was found depending on different parameters such as the nature of extractant, the temperature and the pH, etc. Optimizing the SSF conditions increased the levansucrase production and this inexpensive enzyme production for such a potent and industrially valuable levansucrase is promising and of considerable commercial interest for biotechnological applications.