Structural elucidation of the exopolysaccharide produced by Curvularia lunata isolate RJ01

JAY JAYUS (Department of Agricultural Product Technology, Faculty of Agricultural Technology, Universitas Jember. Jl. Kalimantan No. 37, Jember 68121, East Java, Indonesia Center of Excellent for Industrial Plant Biotechnology, Universitas Jember. Jl. Kalimant)
ROBBY AKROMAN (Department Graduate School of Biotechnology, Universitas Jember. Jl. Kalimantan No. 37, Jember 68121, East Java, Indonesia)
NURHAYATI NURHAYATI (Center for Development of Advanced Sciences and Technology, Universitas Jember. Jl. Kalimantan No. 37, Jember 68121, East Java, Indonesia)
ARI SATIA NUGRAHA (Drug Utilisation and Discovery Research Group, Faculty of Pharmacy, Universitas Jember. Jl. Kalimantan 37, Jember 68121, East Java, Indonesia)
BAMBANG PILUHARTO (Department of Chemistry, Faculty of Math and Natural Science, Universitas Jember. Jl. Kalimantan No. 37, Jember 68121, East Java, Indonesia)
ROBERT JAMES SEVIOUR (Biotechnology Research Centre, La Trobe University. P.O. Box 199, Bendigo, VIC 3552, Australia)

Biodiversitas Journal of Biological Diversity
Vol. 22 No. 5 (2021)

Abstract. Jayus J, Akroman R, Nurhayati, Nugraha AS, Piluharto B, Seviour RJ. 2021. Structural elucidation of the exopolysaccharide produced by Curvularia lunata isolate RJ01. Biodiversitas 22: 2699-2705. An exopolysaccharide (EPS) was recovered from culture filtrates of the fungus Curvularia lunata isolate RJ01 prepared in Jember, Indonesia. Based on a prominent peak at 883 cm-1, FTIR analysis suggested it is a ?-D-glucan, a proposal confirmed by subsequent nuclear magnetic resonance (NMR) analysis which showed anomeric protons omit the signal at d4.37 and 4.8 ppm, and sugar proton signal in the region of 2.5 to 4.2 ppm. High-performance liquid chromatography (HPLC) analysis of the acid hydrolysates of this glucan revealed the presence of glucose (64%) and a mixture of galactose and mannose (36%). Digestion with (1-->3)-?- and (1-->6)-?-glucanase from Acremonium sp. IMI 383068 gave consistent linear products of (1-->3)-?-glycosidic linkages, since the glucan was digested by (1-->3)-?-glucanase only. The rheological behavior of aqueous EPS solution suggests it behaves as a pseudoplastic non-Newtonian fluid and thus has the potential for use as a thickening agent in foods. This study is the first report on the structural elucidation of EPS from C. lunata.