title: Optimization of exopolysaccharide production in submerged culture of Daedalea dickinsii and its antioxidant activity.
abstract: The major nutrients, pH and temperature were evaluated for the exopolysaccharide (EPS) production by Daedalea dickinsii in submerged culture to derive an optimal medium composition and conditions as follows: 50 g/L maltose, 5 g/L soy peptone, 5 mM CaCl(2), at pH 6.0 and 28 °C. A purified EPS fraction was attained from gel filtration chromatography and its major molecular characteristics were determined. FT-IR spectral analysis revealed the prominent characteristic groups of polyhydric alcohols. GC analysis and NMR spectrum showed its major molecular composition of glucose and galactose. Furthermore, thermogravimetric analysis indicated its degradation temperature (T(d)) of 189 °C. The antioxidant activity of the EPS fraction showed a correlation with the molecular properties. It might be attributed to the functional groups in the EPS fraction, which can donate electrons to reduce the radicals to a more stable form or react with the free radicals to terminate the radical chain reaction.
authors.affiliation: College of Food and Biological Engineering, Zhengzhou University of Light Industry, Zhengzhou, 450002, Henan, People's Republic of China.
authors.forename: Duo-Bin
authors.initials: DB
authors.lastname: Mao
authors.forename: Chao-Wen
authors.initials: CW
authors.lastname: Shi
authors.forename: Jian-Yong
authors.initials: JY
authors.lastname: Wu
authors.forename: Chun-Ping
authors.initials: CP
authors.lastname: Xu
mesh_terms: D000975:Antioxidants / Q000737:chemistry*; D001487:Basidiomycota / Q000378:metabolism; D018533:Biomass; D019149:Bioreactors; D002244:Carbon / Q000737:chemistry; D002849:Chromatography, Gas; D002850:Chromatography, Gel; D005285:Fermentation; D005609:Free Radicals; D005690:Galactose / Q000737:chemistry; D005947:Glucose / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D025282:Mycelium / Q000378:metabolism; D009584:Nitrogen / Q000737:chemistry; D011134:Polysaccharides / Q000096:biosynthesis*; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013818:Thermogravimetry
chemical_list: D000975:Antioxidants; D005609:Free Radicals; D011134:Polysaccharides; D002244:Carbon; D005947:Glucose; D009584:Nitrogen; D005690:Galactose