Physiological states and energetic adaptation during growth of Pseudomonas putida mt-2 on glucose
Physiological states and energetic adaptation during growth of Pseudomonas putida mt-2 on glucose
复制标题
DOI：
10.1007/s00203-008-0380-8
复制
发表时间：
2008-05
影响因子：
2.8
通讯作者：
L. Latrach Tlemçani;D. Corroler;D. Barillier;R. Mosrati
中科院分区：
文献类型：
--
作者：
L. Latrach Tlemçani;D. Corroler;D. Barillier;R. Mosrati
以葡萄糖为初始碳源和能源，对恶臭假单胞菌-2在好氧分批培养条件下的生长动力学进行了研究。细胞的生长是连续的，中间产物的积累有三个阶段：(1)葡萄糖主要转化为葡萄糖酸和2-酮葡萄糖酸，(2)葡萄糖酸转化为2-酮葡萄糖酸，(3)后者在葡萄糖酸耗尽后被消耗。生长动力学和产量的检测表明，葡萄糖通量主要面向周质内的氧化还原，较少面向生物合成。呼吸商、CO_2/生物量和O_2/生物量的值是各阶段的特征。在使用这些底物时，总是检测到主要的酶活性，这意味着伴随的同化是可能的。然而，这些活动的水平在增长过程中各不相同。膜转化似乎有很大的能量贡献，解释了葡萄糖相比葡萄糖酸和2-酮葡萄糖酸相比获得更高的比生长率。这一点从屈服沙子的演变过程中也很明显。虽然这三条汇聚的途径是可操作的，并且可以由基因控制，但文化在连续阶段的发展突显了对能量需求的总体调控水平。
Kinetic study of growth ofPseudomonas putidamt-2 was investigated in batch culture under aerobic conditions, on glucose as initial carbon and energy source. Cell growth was continuous and three phases were found regarding accumulation of intermediates: (1) glucose was largely converted to gluconate and 2-ketogluconate, (2) then gluconate was converted to 2-ketogluconate and (3) the latter was consumed after gluconate depletion. Examination of growth kinetics and yields showed that glucose flux was mainly oriented to oxidation reduction in the periplasm and less towards biosynthesis. Values of respiratory quotient and of CO2/biomass and O2/biomass yields were characteristic of each phase. Main enzymatic activities involved in the use of these substrates were always detected meaning that concomitant assimilation is possible. However the levels of these activities varied during growth. Membrane conversions seem to have a significant energetic contribution explaining the higher specific growth rate obtained in glucose phase compared to gluconate and 2-ketogluconate ones. This is also noticeable through the evolution of the yieldsand. Although the three convergent pathways are operational and can be genetically controlled, the progression of the culture in successive phases highlights an overall level of regulation in response to the energetic needs.