Structural analysis of an aluminum-binding capsular polysaccharide produced by Acidocella aluminiidurans strain AL46, an aluminum-tolerant bacterium isolated from plant roots in a highly acidic swamp in actual acid sulfate soil. (December 2020)

• Record Type: Journal Article
• Authors: Aizawa, Tomoko; Urai, Makoto
• Is Part Of: Carbohydrate research. Volume 498(2020)
• Publication Date: 2020-12
• Subjects: Actual acid sulfate soil -- Aluminum-tolerant bacterium -- Acidocella aluminiidurans -- Aluminum-binding capsular polysaccharide -- Structure -- NMR spectroscopy; Carbohydrates -- Periodicals; Chemistry, Organic -- Periodicals; Biochemistry -- Periodicals; Carbohydrates -- Periodicals; Chimie organique -- Périodiques; Glucides -- Périodiques; Biochemistry; Carbohydrates; Chemistry, Organic; Periodicals; Electronic journals; 507.78
• DOI: 10.1016/j.carres.2020.108163
• Languages: English
• ISSNs: 0008-6215

Abstract

Abstract: Acid sulfate soil is found throughout Southeast Asia, and its strong acidity (pH 2–4) is accompanied by various plant growth-inhibiting factors that can reduce crop production. Among these factors, aluminum elution from the soil due to soil acidity strongly inhibits crop growth and is particularly problematic for agricultural production. We previously isolated Acidocella aluminiidurans strain AL46, a highly aluminum-tolerant bacterium, from the rhizospheres of the grass Panicum repens, inhabiting the acid sulfate soil in Vietnam. To elucidate the mechanism underlying the high aluminum tolerance of strain AL46, in the present study, we investigated the aluminum-adsorption ability of strain AL46 surface polysaccharides and confirmed the strong adsorption ability of the capsular polysaccharide (AL46CPS). Based on this finding, we further determined the chemical structure of AL46CPS using 1 H and 13 C NMR spectroscopy by conducting 2D DQF–COSY, TOCSY, HSQC, HMBC, and NOESY experiments. AL46CPS comprises a trisaccharide repeating unit with the following structure: [→2)-β-d -Rha p -(1 → 3)-α-d -Rha p -(1 → 2)-α-d -Rha p -(1→] n . These findings highlight the potential application of AL46CPS as a new aluminum-adsorbing substance in acidic environments to prevent crop loss. Graphical abstract: Image 1 Highlights: Acidocella aluminiidurans strain AL46 is a highly aluminum-tolerant bacterium. AL46 capsular polysaccharide (AL46CPS) adsorbed aluminum. We determined the chemical structure of the AL46CPS. AL46CPS consists of a trisaccharide repeating unit.