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

• Published in: World journal of microbiology & biotechnology 2016-12, Vol.32 (12), p.206-206, Article 206
• Main Authors: Hirabayashi, Katsuki, Kondo, Nobuhiro, Hayashi, Sachio
• Format: Article
• Language: English
• Subjects: Applied Microbiology; Biochemistry; Biomedical and Life Sciences; Biotechnology; Environmental Engineering/Biotechnology; Fungal Proteins - metabolism; Gas Chromatography-Mass Spectrometry; Glucans - chemistry; Hydrolysis; Life Sciences; Magnetic Resonance Spectroscopy; Microbiology; Molecular Structure; Molecular Weight; Original Paper; Saccharomycetales - enzymology; Saccharomycetales - metabolism; Solubility; Water - chemistry
• ISSN: 0959-3993; 1573-0972
• DOI: 10.1007/s11274-016-2167-4

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 13 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.