根瘤菌属胞外多糖的研究

STUDIES 0N THE EXTRACELLULAR POLYSACCHARIDES OF RHIZOBRIUM SPP.

本文研究了豌豆根瘤菌(Rhizobum Leguminosarum),苜蓿根瘤菌(R. meliloti),三叶草根瘤菌(R. trifolii),菜豆根瘤菌(R. phaseoli),豇豆根瘤菌(Rradyrhizobium sp.(Vigna))和大豆根瘤菌(R. Japonicum)产生的胞外多糖化学组分的差异,结果表明,不同种的根瘤菌能产生具有不同组分的胞外多糖,其多糖组分的差异主要表现在糖醛酸和甘露糖的含量。豌豆根瘤菌、三叶草根瘤菌,菜豆根瘤菌产生的胞外多糖含有糖醛酸,大豆根瘤菌和苜蓿根瘤菌产生的胞外多糖一般不含有糖醛酸。根瘤菌有快生型和慢生型之别,这种差异也可由其产生的胞外多糖组分看到,一般快生型根瘤菌:豌豆根瘤菌,苜蓿根瘤菌,菜豆根瘤菌,三叶草根瘤菌,(包括最近证明的快生型大豆根瘤菌)的胞外多糖中甘露糖所占百分比较低(低于20％),葡萄糖所占的百分比较高(高于60％),而慢生型根瘤菌:大豆根瘤菌和豇豆根瘤菌的胞外多糖中甘露糖所占百分比较高(高于36％),葡萄糖所占的百分比较低(低于50％)。

The chemical composition of extracellular polysaccharides of Rhizobium leguminosarum, R. trifolii, R. phaseoli, R. meliloti. Bradyrhizobium sp. (vigna) and R. japonicum were investigated by using a gas-chromatographic method. Extracellular polysaccharide of Rhizobium consist of glucos galactose, mannose and uronic acid. Different Rhizobium sp. will produced different composition of polysaccharide. The differences between this polysaccharide are the presence and content of uronic acid and mannose. Thus, the polysaccharide of R. leguminosarum, R, trifolii, R. phaseoli and Bradyrhizobium sp. (vigna) contained glucose, galactose, mannose and uronic acid. The polysaccharide of R. meliloti and R. japonicum generally contained glucose, galactose and mannose, but not uronic acid. It was found that fast-growing Rhizobium sp (R. leguminosarum, R. trifolii, R. phaseoli and R. meliloti) had polysaccharide with relatively lower content of mannose and higher content glucose than that of slow-growing Rhizobium sp. (R. japonicum and Bradyrhizobium sp. (vigna)。 Similarly, the fast-growing R. japonicum polysaccharide also different in their composition from the slow-growing. The fast growing R. japonicum polysaccharide showed a small proportion mannose and higher content of glucose than the slow-growing R. japonicum strain。