Organic and inorganic phosphorus uptake by bacteria in a plug-flow microcosm
Organic and inorganic phosphorus uptake by bacteria in a plug-flow microcosm
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DOI：
10.1007/s11783-013-0494-3
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发表时间：
2013-02
影响因子：
6.4
通讯作者：
Jinbo Zhao;Xuehua Liu
中科院分区：
文献类型：
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作者：
Jinbo Zhao;Xuehua Liu
磷（P）是维持自然水分生产力的重要营养元素。颗粒态和溶解态的有机磷和无机磷是初级生产者和次级生产者生物有效磷的重要来源。本文描述了一个模拟Plym河沉积物和孔隙水中细菌群落的微宇宙系统，并给出了细菌对无机磷和有机磷的吸收速率。研究了淡水细菌对植酸和葡萄糖-6-磷酸两种有机磷化合物的吸收特性。生物反应器包括填充有两种类型的小玻璃珠的玻璃柱，细菌生物膜可以在玻璃柱上形成。采用不同孔隙率的玻璃微珠模拟河流SPM。将筛选出的磷化合物加入到微宇宙的入流中，通过测量出流中磷浓度的阶跃变化来研究细菌对营养物质的吸收行为。结果表明，有机磷在土壤中转化为无机磷，但转化率与磷的形态有关。一个实验表明植酸（难降解）可以从生物膜表面置换磷酸盐;另一个实验表明D-葡萄糖-6-磷酸（不稳定）可以被细菌水解和利用。结果还表明，细菌可能会破坏C-P键来利用碳。进一步的实验应该研究在微宇宙系统中改变C：N：P比例的影响，以确定哪些营养物质限制细菌的吸收。
Phosphorus (P) is a vital nutrient for sustaining natural water productivity. Both particulate and dissolved forms of organic and inorganic P are potentially important sources of bioavailable P for primary and secondary producers. A microcosm system to imitate the bacterial community in Plym river sediment and pore water is described and bacterial uptake rates for inorganic and organic phosphorus are presented in this paper. The aim of this study was to investigate the uptake of two organic phosphorus compounds (phytic acid and D-glucose-6-phosphate) by freshwater bacteria. The bioreactors comprise glass columns packed with two types of small glass beads on which bacterial biofilm can develop. The glass beads with different porosity were introduced to simulate River SPM. The selected P compounds spiked into the inflow of the microcosm, and measured the step change of P concentration in the outflow to investigate the behavior of bacterial uptake of nutrients. The results showed that organic phosphorus was converted into inorganic phosphorus but the conversion rate depended on the type of phosphorus species. One experiment suggested that phytic acid (refractory) could displace phosphate from the biofilm surface; the other experiment showed that D-glucose-6-phosphate (labile) could be hydrolysed and utilized easily by the bacteria. The results also suggested that bacteria might break down the C-P bonds to utilize the carbon. Further experiments should investigate the effect of varying the C:N:P ratio in the microcosm system to determine which nutrient limits bacteria uptake.