靈芝不同生長階段液態培養菌絲與子實體之水溶性多醣特性

Abstract

為瞭解靈芝生長過程熱水可溶多醣之產量與所含(1,3)-β-D-葡萄聚醣性質的變化，本論文選用BCRC 36041、BCRC 36123與一商業菌株，觀察菌絲與子實體生長過程中熱水可萃取之多醣含量與其(1,3)-β-D-葡萄聚醣含量比例，並同時分析(1,3)-β-D-葡萄聚醣的分支度與分子量分布。菌絲培養採用液態靜置培養方式，三種菌絲之生長速度有明顯的差異，雖菌絲生長量均隨天數而增長，但以BCRC 36041的生長量最高。實驗結果同時發現，菌絲生長量不與多醣產生量成正比，BCRC 36041的菌絲量為三菌種最高,但多醣產量則以BCRC 36123 最多。此外，各菌種以培養到第22天與第27天得到其最高的多醣與(1,3)-β-D-葡萄聚醣產量。菌絲體液態發酵培養之多醣分子量分布多集中於中分子量及低分子量區分，各菌種的多醣之分子量分布特徵與分支度於培養第12天後即無明顯差異。 熱水可萃取之子實體多醣及(1,3)-β-D-葡萄聚醣含量以第三生長階段(蕈傘分化期) 最高，其多醣分子量分布之高分子量區分之比例高於菌絲體液態培養之多醣，且此區分之(1,3)-β-D-葡萄聚醣在多醣中比例有隨著生長階段而增加的趨勢。故可初步推估第五期雖然可萃出之多醣量較少，但其多醣品質相較於其他生長階段較佳。綜實驗結果顯示，同一菌種之菌絲液態發酵培養多醣與子實體多醣相較，前者之(1,3)-β-D-葡萄聚醣在多醣中比例多集中於高分子量與中分子量區分，且於培養第17天後其多醣特性則十分相近; 而子實體多醣中，高分子量之(1,3)-β-D-葡萄聚醣在多醣中比例則要在老熟期時比例才會顯著增高。

To investigate the characteristics changes of hot water extractable polysaccharides and (1,3)-β-D-glucans from Ganoderma lucidum during growth, strains of BCRC 36041, BCRC 36123 and a commercial one are selected in this study. We evaluated hot water extractable polysaccharides and the ratio of its contents in (1,3)-β-D-glucans, and analyzed the degree of branching and the distribution of molecular weight in (1,3)-β-D-glucans. Mycelium was propagated in static liquid culture, three strains showed significant difference in the growth rate. Although the mycelium bimomass increased with culture days, the production of polysaccharides was not propotional to mycelium biomass. BCRC 36041 grew most mycelium, while BCRC 36123 produced most polysaccharide among three strains. Most polysaccharides and (1,3)-β-D-glucans were obtained in 22 and 27 days of culture. The distribution of molecular weight of polysaccharide from mycelium liquid culture appeared mostly in medium molecular weight and low molecular weight fractions. There was no obvious difference in the distribution of molecular weight and the degree of branching in polysaccharide from three strains after 12 days of culture. We can get the highest hot water extractable polysaccharides and (1,3)-β-D-glucans from fruiting bodies of the 3rd culture stage (the stage of pileus differentiation), the ratio of high molecular weight fraction is higher than that of polysaccharides cultured from mycelium liquid culture, and the proportion of (1,3)-β-D-glucans in polysaccharides icreased by growth stages. The qualities of polysaccharide were better than that extracted from another growth stage , although the extactable polysaccharides were less in 5th stage. Comparing the polysaccharides extracted from mycelium liquid culture and fruiting bodies, the former showed that the proportion of (1,3)-β-D-glucans in polysaccharides more concentrated in high molecular weight and medium molecular weight fractions. The characteristics of polysaccharides extracted from mycelium liquid culture kept similar after the 17th days of culture, but higher ratio of (1,3)-β-D-glucans in polysaccharides would probality appear in fruiting bodies of more mature stages.