Evaluation of amino acid effect on the dissolution rates of amorphous silica

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K05711
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Petrology/Mineralogy/Economic geology
• Research Institution: Kagoshima University
• Principal Investigator: Kawano Motoharu 鹿児島大学, 理工学域理学系, 教授 (80224814)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: アモルファスシリカ / アミノ酸 / 溶解速度 / 吸着

Outline of Final Research Achievements

Dissolution experiments of amorphous silica by interaction of amino acid were performed to evaluate the effect of biological organic molecules on the dissolution rates of amorphous silica. Additionally, adsorption experiments of amino acids on the amorphous silica surface were carried out to conform the adsorption affinity of amino acids for the amorphous silica. The dissolution experiments were conducted by the flow through system using 0.1 g of amorphous silica and 10 mmol/L amino acids solutions (Cys, Asn, Ser, Trp, Ala, Thr, His, Lys, Arg）at constant solution pH of 6, 5, 4. Results indicated that the basic amino acids (His, Lys, Arg) increased the dissolution rate by about 8-fold, and other amino acids showed about 2-fold increase. These enhancement of dissolution by interaction with amino acids was consistent with the concentrations of cationic species of amino acids molecules, and also with the adsorption affinity of amino acids for the amorphous silica surface..

Free Research Field

鉱物科学

Academic Significance and Societal Importance of the Research Achievements

地球表層環境は鉱物圏と生命圏の重複領域であるため、この環境での鉱物の生成や溶解は生命研の影響を強く受けていることが想定される。今回の実験使用したアミノ酸はタンパク質を構成する主要分子であるため、アミノ酸分子によるアモルファスシリカの溶解促進効果が認められたことは、生命圏による鉱物圏への影響を評価するうえで重要な意義がある。