多型炭角菌的培养及多糖提取

多型炭角菌在4%葡萄糖,1%蛋白胨,250mL三角瓶装培养液80mL,pH6.5,25℃的培养条件下生长最好,发酵终点为168小时。正交试验得到K+, Mg2+,Ca2+, Zn2+, Fe2+, Mn2+和Cu2+等金属离子的最适浓度分别为0.15%, 0.03%, 0.05%, 0.0015%, 0.001%, 0.00005%和 0.0002%。对培养得到的菌丝体进行多糖提取,得到2种粗多糖:X-1(水溶性多糖)和X-2(碱溶性多糖);从发酵液提取的粗多糖为X-3。经Sephadex G-100和 Sephadex G-150凝胶柱层析,收集、合并的单一峰位部分经聚丙烯酰胺凝胶电泳及纸层析均呈现为单一斑点。多糖酸水解后均能与茚三酮显色,蛋白质组成分析表明其分子中富含16种氨基酸。

CULTIVATION AND POLYSACCHARIDE EXTRACTION OF XYLARIA POLYMORPHA

Xylaria polymorpha was fermented in 80mL liquid medium of 4% glucose and 1% peptone in 250mL shake flask at pH6.5, 25℃ for 168 hours. Orthogonal experiments were designed to determine the suitable concentration of metal ions. The results indicated that 0.15% K+,0.03% Mg2+, 0.05% Ca2+, 0.0015% Zn2+, 0.001% Fe2+, 0.00005% Mn2+, 0.0002% Cu2+ were optimum. In 250L batch reactor, pH value was measured at intervals of 4 hours, deoxidize sugar was recorded at a 12 h interval and dissolved oxygen level was kept above 40%. Fermentative determination is at the 75th hour. Water- and alkali-extracted methods were used for extration of polysaccharides from the mycelium. The fermented solution was precipitated with alcohol and CTAB and proteins were thrown away with Sevag method. The remains were dissolved with NaCl solvent and dialysed with water. The result is that two kinds of polysaccharides, X-1 ( the water-soluble component ) and X-2 ( the alkali-soluble component ) , were gained. Their dry weight was recorded. Polysaccharide X-3 was also obtained in the fermented solution. Each of polysaccharides was proved to be homogeneous after examination by using chromatography on Sephadex G-100 and Sephadex G-150 columns, PAGE and paper chromatography. The polysaccharides include 16 amino acids. Their structures were analysized by I. R. spectrum and 1H-NMR spectrum.