Characterization of a recombinant L-rhamnose isomerase from Dictyoglomus turgidum and its application for L-rhamnulose production.
A putative recombinant enzyme from Dictyoglomus turgidum was characterized and immobilized on Duolite A568 beads. The native enzyme was a 46 kDa tetramer. Its activity was highest for L-rhamnose, indicating that it is an L-rhamnose isomerase. The maximum activities of both the free and immobilized enzymes for L-rhamnose isomerization were at pH 8.0 and 75 °C in the presence of Mn(2+). Under these conditions, the half-lives of the free and immobilized enzymes were 28 and 112 h, respectively. In a packed-bed bioreactor, the immobilized enzyme produced an average of 130 g L-rhamnulose l(-1) from 300 g L-rhamnose l(-1) after 240 h at pH 8.0, 70 °C, and 0.6 h(-1), with a productivity of 78 g l(-1) h(-1) and a conversion yield of 43 %. To the best of our knowledge, this is the first report describing the enzymatic production of L-rhamnulose.
Department of Bioscience and Biotechnology, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, Republic of Korea.
Yeong-Su
YS
Kim
Kyung-Chul
KC
Shin
Yu-Ri
YR
Lim
Deok-Kun
DK
Oh
D019747:Aldose-Ketose Isomerases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D001419:Bacteria / Q000201:enzymology* / Q000235:genetics; D019149:Bioreactors; D002413:Cations, Divalent / Q000378:metabolism; D003067:Coenzymes / Q000378:metabolism; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000378:metabolism*; D006601:Hexoses / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008345:Manganese / Q000378:metabolism; D008970:Molecular Weight; D055503:Protein Multimerization; D021122:Protein Subunits; D013696:Temperature
D002413:Cations, Divalent; D003067:Coenzymes; D004800:Enzymes, Immobilized; D006601:Hexoses; D021122:Protein Subunits; D008345:Manganese; D019747:Aldose-Ketose Isomerases; C062878:L-rhamnose isomerase