TERRAPUB Aqua-BioScience Monographs


Vol. 11 (No. 1), pp. 1–46, 2018 doi:10.5047/absm.2018.01101.0001

Degradation of Plant-derived Carbohydrates in Wetlands

Tetsuya Ogino, Wen Liu and Haruhiko Toyohara*

Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa, Sakyo, Kyoto 606-8502, Japan
*e-mail: toyohara@kais.kyoto-u.ac.jp

(Received on April 17, 2015; Accepted on March 15, 2016; Online published on January 30, 2018)

Abstract: Corbicula japonica is one of the most important bivalves in inland fishery resources. Stable isotopic studies have shown that it can assimilate plant-derived hard-degradable carbohydrates. Further studies revealed that this species has endogenous enzymes to digest these carbohydrates. We investigated the ability of various organisms to degrade hard-degradable carbohydrates in wetlands from subarctic to subtropical zones and found that they could contribute to their degradation. We found that the enzymes secreted from organisms would bind to the sediment and contribute to the degradation of cellulose. We defined these enzymes as "the environmental enzymes". Comparison of various sediments revealed that the binding abilities of the sediment for the environmental enzyme were ascribable to oxidized metal, organic matters and the ratio of sand, silt and clay. Regeneration of the wetlands will be important to improve coastal environmental conditions because nearly half of the wetlands have been lost in the last century. Geological diversity as well as biological diversity should be considered to regenerate the wetlands, because the function of environmental enzyme system depends on their contents in the sediments.

Keywords: cellulase, cellulose, Corbicula japonica, environmental enzyme, sediment, wetland


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