| Abstract: | 舞菇(Grifola frondosa)為一種食藥用的真菌，代謝產物—多醣體，有抗腫瘤和保肝的療效，而以具有β﹣1→3﹣及β﹣1→6﹣為鍵結的葡聚醣，最具有藥理功效，故對於如何以人工培養舞菇並獲得多醣體值得加以探討。本研究以搖瓶及發酵槽培養的方式來探討舞菇菌絲生長及其多醣體的產量。 舞菇在搖瓶實驗發現glucose、fructose、sucrose及corn starch四種碳源中，以30g/L的corn starch能得到最好的菌絲生長及多醣體產量。氮源以6g/L的corn steep powder (CSP) ，就菌體及胞外多醣體的產量而言，優於yeast extract與malt extract，但胞內多醣體含量則是CSP及malt extract是一樣的。培養基初始pH值以pH 6有較佳的多醣產量，可得到菌絲乾重1.93mg/mL、胞內多醣1.28mg/mL以及胞外多醣10.69mg/mL的產量，pH5的效果次之。 以7L的攪拌式發酵槽經過十四天的培養，發現三種通氣量中(0.5,1.0,1.5vvm)，以1.0 vvm可以得到最佳的菌絲重量1.43 mg/mL，胞內多醣1.49mg/mL，以及胞外多醣14.25mg/mL的產量﹔以1.5 vvm所得的多醣體含有最多胞外β﹣1→3﹣D﹣glucans含量111.90μg/mL LE﹔以1.0 vvm則可以得到胞內多醣體中最多的β﹣1→3﹣glucans的含量10.45μg/mL LE。 以7L的氣舉式發酵槽經過十四天的培養，以0.5 vvm可以得到最佳的菌絲重量1.33 mg/mL，以及胞外多醣12.69mg/mL的產量﹔IPS以1.0 vvm的1.41 mg/mL較佳，所以氣舉式發酵槽中以0.5vvm是比較好的選擇，三種通氣量中，1.5 vvm所測得的多醣體含有最多胞外β﹣1→3﹣glucans含量40.14μg/mL LE，以及胞內多醣體中最多的β﹣1→3﹣glucans的含量11.56μg/mL LE。 經由凝膠透過層析法(Gel permeation chromatography)方法分析其分子量，舞菇多醣體經由七天發酵後，在攪拌式發酵槽中EPS是以0.5 vvm最大2.0x106 Da，IPS是以0.5 vvm所得到的分子量最大5.0x105 Da，1.5 vvm的分子量差距最多，5.3x103 Da到4.8x105 Da; 氣舉式發酵槽多醣體分子量經過七天的發酵，EPS以0.5 vvm最大3.5x105 Da，但是分佈差距也最大﹔IPS的分子量以1.0 vvm 所產生的分子量3.5x105 Da為最大。
Grifola frondosa is am edible medicinal fungi with medicinal effect in anti-tumor and liver protecting. The polysaccharide produced by the fungi having the chemical structure of β-1→3- andβ-1→6-glucans,is believed to have biological and pharmaceutical activities. Therefore,research in the cultivating Grifola frondosa for biomass and its polysaccharide production is in high demand. Results show that shake flask fermentation the most suitable carbon source was corn starch at concentration of 30 grams per liter of medium for the polysaccharical for mation,as compared to glucose, fructose and sucrose, where the biomass, exo-polysaccharide (EPS) and intra-polysavvharide (IPS) were 1.70mg/mL, 7.74 mg/mL and 1.12 mg/mL ,and the use of corn steep powder is better than yeast extract and malt extract as N-source. At pH 6 is the best among 4 tested initial pH in fermentation media to have mycelium dry weight(MDW) 1.93 mg/mL EPS, 10.69 mg/mL, and 1.28 mg/mL IPS. The 7 liter stirred tank fermentor(STF) studies indicate,aeration rate at 1.0vvm favors the maximum production in 1.43 mg/mL of MDW,14.25 mg/mL EPS,and 1.49 mg/mL IPS after eight days in the 7 liter fermentor while 1.5vvm obtained the highest β-1→3-glucans , 111.90μg/mL LE in the EPS. The 7 liter the air-lift fermentor(ALF) studies, aeration at 0.5 vvm favors the production of the mycelium(1.33 mg/mL) and EPS (12.69 mg/mL ),while IPS was best with 1.0vvm(1.41mg/mL). Theβ-1→3-glucans content, in the EPS were similar in all there aeration rate in ALF(40.14μg/mL LE) ,but were higher in IPS(11.56 μg/mL LE),with the 1.5 vvm aeration the best. The molecule weight (MW) of the polysaccharide after days 7 of fermentation, as analysed by gel permention chromatography (GPC) was the highest in the STF with 0.5 vvm (EPS: 2.0x106 Da;IPS: 5.0x105Da). After days 7 of fermentation on the air-lift fermentor was the EPS highest MW 3.5x105Da with 0.5vvm, and IPS highest MW 3.5x105Da with 1.0vvm. |
