Expression of mannanase gene from Bacillus circulans NT 6.7 in Escherichia coli and Lactobacillus plantarum

The mannanase gene of B. circulans NT 6.7 was cloned and expressed in Escerichia coli and food-grade Lactobacillus plantarum expression system. B. circulans NT 6.7 mannanase gene consisted of 1,083 nucleotides encoding 360 amino acid residues which belonging to glycosyl hydrolase family 26. In E. coli system, mannanase gene was cloned into pET21d and expressed in E. coli BL21* (DE3). Beta-mannanase activities in culture supernatant and cell were 37.14 and 515.40 u/ml, respectively. The secreted recombinant β-mannanase was 20 times higher than native enzyme at the same production scale and the enzyme activity of this recombinant β-mannanase was 30 times higher than the recombinant β-mannanase from B. circulans CGMCC 1416 and B. circulans CGMCC 1554 which were performed by the same expression system. So, this expression system was suitable for production of recombinant βmannanase from B. circulans NT6.7. For food grade expression system, mannanase gene was cloned into pSIP403 and expressed in L. plantarum WCFS1 Δalr. The recombinant βmannanase was produced only in the cells with relatively low activity at 0.82 u/ml. This study showed the expression system to produce recombinant β-mannanase from B. circulans NT 6.7 which suitable for industrial applications and also presented the food grade recombinant β-mannanase production for food and feed application.