Enzymatic conversion of kelp biomass for biofuels and health beneficial products.

2022 Fiscal Year Annual Research Report

• Project/Area Number: 20H02776
• Research Institution: Hokkaido University
• Principal Investigator: FOX BRIAN 北海道大学, 農学研究院, 教授 (90812397)
• Co-Investigator(Kenkyū-buntansha): 細川 雅史 北海道大学, 水産科学研究院, 教授 (10241374) ; 栗原 秀幸 北海道大学, 水産科学研究院, 教授 (40234570) ; 高須賀 太一 北海道大学, 農学研究院, 准教授 (70748409)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: Kelp hydrolysis / alginate / laminarin

Outline of Annual Research Achievements

In this year, we had focused on submitting the manuscript entitled "Quantitative Analysis of The High‐Yield Hydrolysis of Kelp by Laminarinase and Alginate Lyase", which describes a minimum enzyme combination to effectively hydrolyze purified laminarin and alginate and kelp Laminaria digitata. The best possible combination (SactELam55A and CaPL18A) was determined and was used for both laminarin hydrolysis and kelp hydrolysis, followed by NIMS analysis and 2D NMR.
Aside from the minimum two enzymes, we also determined a new polysaccharide-degrading enzyme that shows a unique positive response to certain metals during hydrolysis. These metals did not give any effect on the above two enzyme activities, thus this enzyme is possible member for three minimum enzyme combination for kelp hydrolysis.
Furthermore, three kelp species, Costaria costata, Fucus distichus sp. evanescens and chorda asiatica, were harvested and analyzed their chemical compositions. Laminarin, alginate, and another fraction containing fucoidans were separated by several chemical pretreatment.

Current Status of Research Progress

2: Research has progressed on the whole more than it was originally planned.

Reason

Although we have accomplished enough with one paper published and two papers awaiting publication, one of our goals is to purify intact fucoidans from natural kelp, which has not been achieved. Thus, we decided to extend the project.

Strategy for Future Research Activity

To achieve highly efficient kelp hydrolysis, we will search for at least two more enzyme functions by gene synthesis, recombinant enzyme preparation, and functional characterization. These enzymes will be added to the already selected minimum enzyme set and reaction optima will be determined for kelp hydrolysis. Three kelp species, Costaria costata, Fucus distichus sp. evanescens and chorda asiatica, will be subjected for enzyme-assisted depolymerization for fucoidan extraction for health beneficial effects on cultured cells.