Solid State Fermentation of a Raw Starch Digesting Alkaline Alpha-Amylase from Bacillus licheniformis RT7PE1 and Its Characteristics

Romana Tabassum,Shazia Khaliq,Muhammad Ibrahim Rajoka,Foster Agblevor

doi:10.1155/2014/495384

Abstract

The thermodynamic and kinetic properties of solids state raw starch digesting alpha amylase from newly isolated Bacillus licheniformis RT7PE1 strain were studied. The kinetic values Q p, Y p/s, Y p/X, and q p were proved to be best with 15% wheat bran. The molecular weight of purified enzyme was 112 kDa. The apparent K m and V max values for starch were 3.4 mg mL−1 and 19.5 IU mg−1 protein, respectively. The optimum temperature and pH for α-amylase were 55°C, 9.8. The half-life of enzyme at 95°C was 17h. The activation and denaturation activation energies were 45.2 and 41.2 kJ mol−1, respectively. Both enthalpies (ΔH ∗) and entropies of activation (ΔS ∗) for denaturation of α-amylase were lower than those reported for other thermostable α-amylases.

Highlights

Starch is an excellent carbon source in nature and major storage product of many economically important crops
Wheat bran (15%) proved to be the best carbon source to support maximum values of all kinetic parameters related to product formation
From the present study it is apparent that production of alpha amylase production by solid state fermentation from 15% wheat bran was higher as compared to 15% gram bran by newly isolated Bacillus licheniformis RT7PE1 strain

Summary

Introduction

Starch is an excellent carbon source in nature and major storage product of many economically important crops. Five groups of enzymes play a key role in the hydrolysis of starch. These enzymes comprise about 30% of the world’s enzyme production. Alpha amylases have a number of applications, including liquefaction of starch in the alcohol, brewing, and sugar industries and in the textile industry for desizing of fabrics [3]. They have applications in laundry and detergents or as antisalting agents and baking such as bread making [3], since thermostability and alkaline characteristics are important features for industrial applications of amylase isolated from alkalophilic organisms [4]

Methods

Results

Conclusion