Jump to Main Content
Cloning and characterization of a modular GH5 β-1,4-mannanase with high specific activity from the fibrolytic bacterium Cellulosimicrobium sp. strain HY-13
- Kim, Do Young, Ham, Su-Jin, Lee, Hyun Ju, Cho, Han-Young, Kim, Ji-Hoon, Kim, Yi-Joon, Shin, Dong-Ha, Rhee, Young Ha, Son, Kwang-Hee, Park, Ho-Yong
- Bioresource technology 2011 v.102 no.19 pp. 9185-9192
- Cellulosimicrobium, Eisenia fetida, Escherichia coli, Micromonospora, active sites, bacteria, catalytic activity, chitin, chitosan, curdlan, enzymes, feed additives, genes, lignin, livestock and meat industry, locust bean gum, mannans, nuts, oats, sugars, xylan
- The gene (1272-bp) encoding a β-1,4-mannanase from a gut bacterium of Eisenia fetida, Cellulosimicrobium sp. strain HY-13 was cloned and expressed in Escherichia coli. The recombinant β-1,4-mannanase (rManH) was approximately 44.0kDa and has a catalytic GH5 domain that is 65% identical to that of the Micromonospora sp. β-1,4-mannosidase. The enzyme exhibited the highest catalytic activity toward mannans at 50°C and pH 6.0. rManH displayed a high specific activity of 14,711 and 8498IUmg⁻¹ towards ivory nut mannan and locust bean gum, respectively; however it could not degrade the structurally unrelated polysaccharides, mannobiose, or p-nitrophenyl sugar derivatives. rManH was strongly bound to ivory nut mannan, Avicel, chitosan, and chitin but did not attach to curdlan, insoluble oat spelt xylan, lignin, or poly(3-hydroxybutyrate). The superior biocatalytic properties of rManH suggest that the enzyme can be exploited as an effective additive in the animal feed industry.