| Summary: | 碩士 === 國立臺灣大學 === 食品科技研究所 === 93 === Liquid culture is an efficient method to produce Ganoderma lucidum polysaccharides. Culture media and cultivating conditions have significant effects on mycelium growth and polysaccharide production. The focus of this study was on the effects of using legumes (black soybean and Astragalus membranaceous Bunge) as media and cultivating conditions on producing yield and properties of G. lucidum polysaccharides. Liquid culture samples of G. lucidum mycelium were obtained from three sources: static cultures in flasks and five-liter experimental and two-hundred-liter fermentors. The concentration of water-soluble polysaccharide and (1, 3)-b-D-glucans having (1, 6)-b-glucosyl branches in culture were used as indices to study the differences of polysaccharides from different sources. The results of static culture experiments indicated that the using of combined legume medium significantly increased the production of polysaccharide and the (1, 3)-b-D-glucans but the using of individual legume as medium did not find significant changes. The analytical data from samples produced in five-liter experimental and two-hundred- liter fermentor indicated that multiple factors was affecting the production of polysaccharides and (1, 3)-b-D-glucans and the effects of using legume medium and temperature (in the range of 18°, 24° and 30°) were more significant than aeration (in the range of 0.25~0.75 vvm). The polysaccharide production could reach 322 mg/dL and (1, 3)-b-D-glucans could reach 152 mg/dL. The optimum condition for production polysaccharides and (1, 3)-b-D-glucans differed on five- and two-hundred-liter fermentors as producing apparatus. It was significantly affected by cultivating condition that of content the (1, 3)-b-D-glucan and its degree of branching in polysaccharides as well as molecular weight distribution of polysaccharides. The occurrence of the (1, 3)-b-D-glucans was exclusive in molecular weight larger than 85 kDa. The results indicated that affecting factors on polysaccharide production from G. lucidum mycelia were complicated quality monitoring was necessary for the processing.
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