Singh S, Hogan S, Feingold D S, Larsen B
Department of Microbiology, University of Pittsburgh, School of Medicine, Pennsylvania 15261.
Microbios. 1987;51(206):7-13.
Mucoid strains of Azotobacter vinelandii, Pseudomonas aeruginosa and Pseudomonas syringae var glycinia synthesize alginate, an extracellular copolymer comprising D-mannuronosyl and L-guluronosyl moieties. Extracellular mannuronan C-5 epimerase, which converts polymannuronate to alginate, was demonstrated in supernatant fluid from cultures of A. vinelandii. However, the enzyme could not be demonstrated, using the same assay, in supernatant fluids of cultures of mucoid strains of P. aeruginosa or of P. syringae var glycinia, or in cell-free sonic extracts of P. aeruginosa. The results suggest that the pathways of alginate biosynthesis in A. vinelandii and Pseudomonas species may differ.
棕色固氮菌、铜绿假单胞菌和丁香假单胞菌大豆致病变种的黏液菌株合成藻酸盐，这是一种由D-甘露糖醛酸和L-古洛糖醛酸部分组成的细胞外共聚物。在棕色固氮菌培养物的上清液中证实了将聚甘露糖醛酸转化为藻酸盐的细胞外甘露糖醛酸C-5差向异构酶。然而，使用相同的测定方法，在铜绿假单胞菌或丁香假单胞菌大豆致病变种的黏液菌株培养物的上清液中，或在铜绿假单胞菌的无细胞超声提取物中均未证实该酶的存在。结果表明，棕色固氮菌和假单胞菌属中藻酸盐生物合成途径可能不同。
