Characterization and enzymatic hydrolysis of hydrothermally treated β-1,3–1,6-glucan from Aureobasidium pullulans

Abstract

The chemical structure of hydrothermally treated β-1,3-1,6-glucan from Aureobasidium pullulans was characterized using techniques such as gas chromatography/mass spectrometry (GC/MS) and nuclear magnetic resonance (NMR). The chemical shifts of anomeric carbons observed in the C-NMR spectra suggested the presence of single flexible chains of polysaccharide in the sample. β-1,3-1,6-Glucan from A. pullulans became water-soluble, with an average molecular weight of 128,000 Da after hydrothermal treatment, and the solubility in water was approximately 10% (w/w). Sample (3% w/v) was completely hydrolyzed to glucose by enzymatic reaction with Lysing enzymes from Trichoderma harzianum. Gentiobiose (Glcβ1 → 6Glc) and glucose were released as products during the reaction, and the maximum yield of gentiobiose was approximately 70% (w/w). The molar ratio of gentiobiose to glucose after 1 h reaction suggested that the sample is likely highly branched. Sample (3% w/v) was also hydrolyzed to glucose by Uskizyme from Trichoderma sp., indicating that it is very sensitive to enzymatic hydrolysis.

Solid-state relaxation NMR dataset for a water-soluble β-(1→3, 1→6)-glucan from Aureobasidium pullulans and schizophyllan from Schizophyllum commune

“…APG was kindly provided from Itochu Sugar Co. (Japan), which was prepared according to a previously reported method [[2], [3], [4]]. SPG was purchased from InvivoGen (USA).…”

Two-dimensional NMR data of a water-soluble β-(1→3, 1→6)-glucan from Aureobasidium pullulans and schizophyllan from Schizophyllum commune

“…The experiment's planning, design, and data processing correspond to the protocol given in Refs. [1] , [2] .…”

“…SPG was purchased from InvivoGen (USA). The water-soluble A. pullulans β-(1→3, 1→6)-glucan was prepared according to a previously reported method [1] , [2] .…”

Ingestion of Exopolymers from Aureobasidium pullulans Reduces the Duration of Cold and Flu Symptoms: A Randomized, Placebo‐Controlled Intervention Study

“…Recently, the effectiveness of -glucan on respiratory diseases has been studied in rodent [30] and human [31][32][33] because their prevalence has increased rapidly. EAP, exopolymers purified from Aureobasidium pullulans SM-2001, containing 13% -1,3/1,6-glucan [20], are used in test foods and have shown potent immunomodulatory activities in a mouse model [16]. However, this study is the first to evaluate the use of EAP against respiratory diseases.…”

“…Dr. Dong-Chan Park). It has been reported that the extracellular polysaccharides isolated from Aureobasidium pullulans are pullulan (poly--1,6-maltotriose-based exopolysaccharide, EPS) [20], aubasidan ( -1,3-D-glucan with -1,6-branches to -1,4 side chains) [21], and -glucan ( -1,3/1,6-D-glucan) [22]. However, the physiological activity of polysaccharides produced by Aureobasidium pullulans has been mainly studied for -1,3/1,6-D-glucan [12].…”