**5. Conclusions**

Enzymes responsible for the metabolism of alginate-derived DEH had not been well characterized in alginolytic bacteria. In the present study, KDG kinase-like gene *flkin* and KDPG aldolase-like gene *flald* in the genome of *Flavobacterium* sp. strain UMI-01 were investigated and the activities of the proteins encoded by these genes were assessed by using recombinant enzymes recFlKin and recFlAld. Analyses for reaction product of recFlKin and recFlAld indicated that these enzymes were KDG kinase and KDPG aldolase, respectively. Thus, the alginate metabolism of *Flavobacterium* sp. strain UMI-01 was considered to be achieved by the actions of FlKin and FlAld along with alginate lyases FlAlyA, FlAlyB and FlAlex, and DEH reductase FlRed. An in vitro alginate-metabolizing system was successfully constructed from the above enzymes. This system could convert alginate to pyruvate and GAP with 38% efficiency. This result indicates that the UMI-01 enzymes are available for the production of high-value materials like KDPG from alginate.

**Acknowledgments:** This study was supported in part by the Program for Constructing "Tohoku Marine Science Bases" promoted by Ministry of Education, Culture, Sports, Science and Technology, Japan.

**Author Contributions:** Ryuji Nishiyama took charge of designing the research and performed biochemical analysis. Akira Inoue performed cloning of *flkin* and *flald* genes and expression of recombinant enzymes. Ryuji Nishiyama, Akira Inoue and Takao Ojima took charge of preparation of manuscript.

**Conflicts of Interest:** The authors declare no conflict of interest.
