FRUCTOSE UPTAKE AND INFLUENCE ON GROWTH OF AND NITROGEN-FIXATION BY ANABAENA-VARIABILIS
FRUCTOSE UPTAKE AND INFLUENCE ON GROWTH OF AND NITROGEN-FIXATION BY ANABAENA-VARIABILIS
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DOI：
10.1128/jb.147.1.227-235.1981
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发表时间：
1981-01-01
影响因子：
3.2
通讯作者：
SPILLER, H
中科院分区：
文献类型：
--
作者：
HAURY, JF;SPILLER, H
果糖被固氮菌A. variabilis在光照下的倍增时间从24 h缩短到8 h。果糖依赖性生长和果糖吸收的动力学都是指数的。在N2固定培养物中果糖摄取的表观Km对于先前未暴露于果糖的细胞为160 μ M，而在适应于果糖的细胞中为50 μ M。皮摩尔量的[14C]果糖从培养基中清除并积累在细丝中。果糖适应细丝的异形胞积累14 C从果糖在20分钟内。短期实验与果糖饥饿的文化提供的证据表明，固氮酶活性，蛋白质和叶绿素含量的变化在1代的时间后，加入果糖。在长期实验中，培养基中最初存在的果糖的量决定了异形胞的数量和包装的细胞体积。当外源果糖浓度> 20 mM时，光合放氧和叶绿素含量下降。
Fructose is specifically taken up by N2-fixing cultures of A. variabilis in the light and lowers the doubling time from 24 to 8 h. The kinetics for both fructose-dependent growth and fructose uptake are exponential. The apparent Km for fructose uptake in N2-fixing cultures is 160 .mu.M for cells not previously exposed to fructose and 50 .mu.M in cells adapted to fructose. Picomolar amounts of [14C]fructose are scavenged from the medium and accumulate in filaments. Heterocysts of fructose-adapted filaments accumulate 14C from fructose within 20 min. Short-term experiments with fructose-starved cultures provide evidence that nitrogenase activity, protein and chlorophyll content change within 1 generation time upon addition of fructose. In long-term experiments, the amount of fructose initially present in the medium determines heterocyst number and packed-cell volume. Photosynthetic oxygen evolution and amounts of chlorophyll decrease with exogenous fructose concentrations > 20 mM.