Yields and Properties of Polysaccharides and (1, 3；1, 6) -b-D-Glucans Extracted from Ganoderma lucidum Mycelium Cultivated at Different Conditions

• Main Authors: Yi-Nung, Lee, 李儀儂
• Other Authors: 呂廷璋
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/28676644532298811143

碩士 === 國立臺灣大學 === 食品科技研究所 === 92 === The immuno-modulating activity of Ganoderma lucidum is an attribute of its polysaccharides. The (1, 3)-β-D-glucans with (1, 6)-β-D- glucosyl branches have been proved to be the most abundant active polysaccharides in a hot-water extract of its fruiting bodies. The objectives of this study were to elucidate the effects of cultivating media and conditions on mycelium growth, yields of polysaccharide and the (1, 3；1, 6)-β-D-glucans and the effects on degree of branching and molecular weight distribution of the β-D-glucans. A fruiting body and a commercial mycelium culture samples were selected as references. The hot-water extraction yields of polysaccharide were 1.92 and 2.51 %, and the yields of the apparent β-D-glucans were 0.49 and 0.13 % for the fruiting body and the commercial mycelium culture sample, respectively. Among five static culture samples using different media with carbon/ nitrogen ratio (C/N) ranged in 16 ~ 142, the contents of mycelium decreased from 0.35 to 0.17 g/dL as C/N increased but the polysaccharide contents increased from 23 to 139 mg/dL in a 21-day cultivation. The concentrations of the β-D-glucans in these polysaccharide samples were in the range of 34.5 ~ 9.9%, comparing to the values of fruiting body and commercial mycelium culture reference as 19.7 and 2.1%, respectively. The using of a five-liter fermentator significantly increased the mycelium growth rate and the yield of polysaccharide but decreased the production of the β-D-glucans with content similar to the commercial mycelium culture sample. The presence of 6 % of black soybean in the medium (as a high nitrogen medium) boosted the growth of the mycelium and caused a medium polysaccharide production and almost suppressed the production of the β-D-glucans. The degree of branching of the (1, 3；1, 6)-β-D-glucans in these samples were in the range of 0.2 to 0.46. Gel-filtration chromatography revealed the molecular weight variations of polysaccharides and β-D-glucans. Both the molecular-weight distribution of polysaccharides and the β-D-glucans was significantly altered by the cultivating conditions. The results of this study indicated that cultivating conditions not only affected the growth rate of the mycelium but also varied the composition of polysaccharides that commonly used as ingredient of functional foods.