%0 Journal Article
%T Solid State Fermentation of a Raw Starch Digesting Alkaline Alpha-Amylase from Bacillus licheniformis RT7PE1 and Its Characteristics
%A Romana Tabassum
%A Shazia Khaliq
%A Muhammad Ibrahim Rajoka
%A Foster Agblevor
%J Biotechnology Research International
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/495384
%X 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 , , , and were proved to be best with 15% wheat bran. The molecular weight of purified enzyme was 112£¿kDa. The apparent and values for starch were 3.4£¿mg mL£¿1 and 19.5£¿IU£¿mg£¿1 protein, respectively. The optimum temperature and pH for ¦Á-amylase were 55¡ãC, 9.8. The half-life of enzyme at 95¡ãC was 17h. The activation and denaturation activation energies were 45.2 and 41.2£¿kJ mol£¿1, respectively. Both enthalpies ( ) and entropies of activation ( ) for denaturation of ¦Á-amylase were lower than those reported for other thermostable ¦Á-amylases. 1. Introduction Starch is an excellent carbon source in nature and major storage product of many economically important crops. A large-scale starch processing industry has emerged in the last century [1]. 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 (endo-1,4-a-D-glucan glucanohydrolase, E.C.3.2.1.1) are extracellular endo enzymes that randomly cleave the 1,4-a linkage between adjacent glucose units in the linear amylose chain and ultimately generate glucose, maltose, and maltotriose units [2]. Alpha amylases derived from microbial sources have great success and replaced the chemical hydrolysis of starch in starch processing industries. 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 also 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]. The microbial ¦Á-amylases for industrial processes are derived mainly from Bacillus subtilis, Bacillus amyloliquefaciens, and Bacillus licheniformis asthey are capable of secreting amylases into the culture supernatant in submerged [5]. The microbial production of alpha-amylase is greatly influenced by the composition of the medium culture and environmental and growth kinetic parameters [5]. However, solid state fermentation provides an interesting alternative for concentrated enzyme production and less purification costs [6]. This work reports the solid state production, kinetic and thermodynamic properties of raw starch-digesting alkaline alpha-amylase from an
%U http://www.hindawi.com/journals/btri/2014/495384/