Cloning, expression and characteisation of l-arabinoseisomerase from anoxybacillus kestanbolensis ac26 sari

L-arabinose isomerase (intramolecular oxidoreductases; EC 5.3.1.4) is an intracellular enzyme and provides reversible isomerization of L-arabinose to L-ribulose or D-galactose to D-tagatose for pentose phosphate pathway. Microbial L-arabinose isomerases draw great attention in terms of synthesis of D-tagatose in industry. Particularly, thermophilic enzymes are preferred for industrial use. Industrial enzymatic reactions that occur at high temperatures reduce the risk of contamination and viscosity of substrate.This work describes the cloning, isolation, and characterization of L-arabinose isomerase from Anoxybacillus kestanbolensis AC26 Sari. A 1503 nt L-arabinose isomerase gene coding for L-arabinose isomerase from Anoxybacillus kestanbolensis AC26 SARI sequenced and cloned into pET28a+ vector. Vector encoding this gene was transformed into E.coli BL21(DE3)pLysS, expressed and purified. It was determined that the purified L-arabinose isomerase optimum temperature is 65 °C and optimum pH is 8.5. It was determined that the enzyme had Km (6.5 mM) for L-arabinose. Metal ion effects to L-AI were observed with cloride salts of Mn+2, Co+2, Mg+2, Fe+2, Ca+2, Cu+2, Li, K and Zn+metal ions. The molecular mass of the L-AI was determined to be 55.6776 kDa on SDS-PAGE. In the light of all data it has been suggested that the enzyme?s biocatalytic properties proved to be one of the important industrial enzymes.