Lignin degrading activities of herbivorous land crabs

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K05173
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 27040:Biofunction and bioprocess engineering-related
• Research Institution: Meijo University
• Principal Investigator: Miyake Katsuhide 名城大学, 理工学部, 教授 (90252254)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: リグニン / 陸ガニ / ラッカーゼ / パーオキシダーゼ / 植食性

Outline of Final Research Achievements

Chiromantes haematocheir and C. dehaani are herbivorous land crabs that live in Japanese maritime forests. They often eat decayed wood and fallen or green leaves. Herbivorous land crabs are thought to degrade plant biomass. Plant biomass consists of three major components: cellulose, hemicellulose, and lignin. Among these components, lignin is refractory organic substance. These crabs seem to express lignin degradation enzymes endogenously. In this study, we sequenced and assembled C. haematocheir and C. dehaani midgut gland transcriptomes. Genes encoding putative enzymes involved in the degradation of biopolymers, such as lignin and cellulose were identified, and their expressions and activities were characterized. Here, we report an analysis of the laccase and peroxidase genes showing the highest expression level in the midgut gland of the land crabs. The properties of laccase and peroxidase showing highest expression and its involvement in plant biomass degradation were studied.

Free Research Field

環境生物工学

Academic Significance and Societal Importance of the Research Achievements

本研究は、バイオマス分解酵素の新規供給源を開拓する研究であり、その対象として草食性陸ガニ類を選択したものである。分解をめざすバイオマス構成因子として、非常に分解の難しいとされるリグニンを選択している。本研究成果では、草食性陸ガニ類から、強いリグニン分解活性を検出できており、またその遺伝子群の単離にも成功した。大腸菌等での生物工学的な生産は十分ではないが、改善できれば、リグニン分解酵素として新しい選択肢を提示できる。