Goebel E M, Krieg N R
J Bacteriol. 1984 Jul;159(1):86-92. doi: 10.1128/jb.159.1.86-92.1984.
The pathways for catabolism of fructose were investigated in the type strains of Azospirillum lipoferum and Azospirillum brasilense grown aerobically with (NH4)2SO4 as the nitrogen source. When grown on fructose, the former species possessed a complete Entner-Doudoroff pathway, whereas the latter species lacked activity for glucose-6-phosphate dehydrogenase. Both species possessed a complete catabolic Embden-Meyerhof-Parnas pathway. Neither species possessed the key enzyme of the hexose monophosphate pathway, 6-phosphogluconate dehydrogenase. Both species could phosphorylate fructose to fructose-1-phosphate by means of a phosphoenolpyruvate-phosphotransferase system, and high activities of 1-phosphofructokinase occurred. Both species possessed glucokinase activity, but only A. lipoferum had hexokinase activity; moreover, the cells of A. brasilense were nearly impermeable to glucose, accounting for the inability of this species to grow on glucose. Both species possessed pyruvate dehydrogenase, a complete tricarboxylic acid cycle, a glyoxylate shunt, and malic enzyme. Analysis of the acidic end products for both species indicated the formation of only small amounts of various organic acids, and most of the titratable acidity was due to utilization of the ammonium ions of the medium. Gluconic acid was not formed during growth of either species on fructose but was detected during growth of A. lipoferum on glucose; this species also possessed an NADP-linked glucose dehydrogenase and gluconokinase.
在以硫酸铵作为氮源进行好氧培养的脂环固氮螺菌和巴西固氮螺菌的模式菌株中，对果糖的分解代谢途径进行了研究。当在果糖上生长时，前一种菌具有完整的恩特纳-杜德洛夫途径，而后一种菌缺乏6-磷酸葡萄糖脱氢酶活性。两种菌都具有完整的糖酵解途径。两种菌都不具有磷酸戊糖途径的关键酶6-磷酸葡萄糖酸脱氢酶。两种菌都可以通过磷酸烯醇式丙酮酸-磷酸转移酶系统将果糖磷酸化为1-磷酸果糖，并且1-磷酸果糖激酶具有高活性。两种菌都具有葡萄糖激酶活性，但只有脂环固氮螺菌具有己糖激酶活性；此外，巴西固氮螺菌的细胞对葡萄糖几乎不可渗透，这解释了该菌不能在葡萄糖上生长的原因。两种菌都具有丙酮酸脱氢酶、完整的三羧酸循环、乙醛酸循环支路和苹果酸酶。对两种菌的酸性终产物分析表明，仅形成少量各种有机酸，并且大部分可滴定酸度是由于培养基中铵离子的利用。在两种菌在果糖上生长期间均未形成葡萄糖酸，但在脂环固氮螺菌在葡萄糖上生长期间检测到葡萄糖酸；该菌还具有一种NADP连接的葡萄糖脱氢酶和葡萄糖激酶。
