Energy requirements for microbial exopolysaccharide synthesis
Energy requirements for microbial exopolysaccharide synthesis
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DOI：
10.1007/bf00414549
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发表时间：
1984-03
影响因子：
2.8
通讯作者：
T. Jarman;G. W. Pace
中科院分区：
文献类型：
--
作者：
T. Jarman;G. W. Pace
计算表明，在高比速率的胞外多糖合成中获得的连续培养物ofXanthomonascampestrisandmucoidPseudomonasaerodynosastries的ATP需求，这种合成是一个显着的比例总细胞ATP需求。然而，取决于比碳水化合物底物更氧化的聚合物取代基的比例，一些，在某些情况下，所有这些能量可以通过在胞外多糖合成过程中产生的NAD（P）H2提供。对X.根据黄原胶取代基的含量，2.2至2.6的Campestrisa P/O比对于作为黄原胶合成的直接结果的能量产生是必需的，以支持该合成的ATP需求。在硫限制的X.然而，白菜型油菜的能量代谢效率低下，表现出低P/O比或低YATP。在这样的培养物中，与P/O比为1至3的最大理论产率0.81至0.87/g葡萄糖相比，来自葡萄糖的外泌多糖的产率为0.62/g葡萄糖。
Calculations indicate that at the high specific rates of exopolysaccharide synthesis obtained in continuous cultures ofXanthomonas campestrisand mucoidPseudomonas aeruginosastrains the ATP demand for this synthesis is a significant proportion of total cellular ATP demand. However, depending upon the proportion of polymer substituents more oxidised than the carbohydrate substrate, some, and in certain cases all of this energy can be provided via NAD(P)H2produced during exopolysaccharide synthesis. For xanthan production byX. campestrisa P/O ratio of 2.2 to 2.6, depending on the content of pyruvyl substituents, would be necessary for energy generation as a direct result of xanthan synthesis to support the ATP demand for this synthesis. In sulphur-limited cultures ofX. campestris, however, energy metabolism is shown to be inefficient, the organism exhibiting either a low P/O ratio or lowYATP. In such cultures the yield of exopolysaccharide from glucose was 0.62/g glucose compared with maximum theoretical yields of 0.81 to 0.87/g glucose for P/O ratio of 1 to 3.