Bordeaux Sciences Agro, UMR1065 Santé et Agroécologie du Vignoble (SAVE), ISVV, Université de Bordeaux, 33140, Villenave d'Ornon, France.
INRA, UMR1065 SAVE, ISVV, 33140, Villenave d'Ornon, France.
Microb Ecol. 2018 Jul;76(1):169-181. doi: 10.1007/s00248-017-1117-5. Epub 2017 Nov 25.
In soilless culture, slow filtration is used to eliminate plant pathogenic microorganisms from nutrient solutions. The present study focused on the characterization and the potential functions of microbial communities colonizing the nutrient solutions recycled on slow filters during a whole cultivation season of 7 months in a tomato growing system. Bacterial microflora colonizing the solutions before and after they flew through the columns were studied. Two filters were amended with Pseudomonas putida (P-filter) or Bacillus cereus strains (B-filter), and a third filter was a control (C-filter). Biological activation of filter unit through bacterial amendment enhanced very significantly filter efficacy against plant potential pathogens Pythium spp. and Fusarium oxysporum. However, numerous bacteria (10-10 CFU/mL) were detected in the effluent solutions. The community-level physiological profiling indicated a temporal shift of bacterial microflora, and the metabolism of nutrient solutions originally oriented towards carbohydrates progressively shifted towards degradation of amino acids and carboxylic acids over the 7-month period of experiment. Single-strand conformation polymorphism fingerprinting profiles showed that a shift between bacterial communities colonizing influent and effluent solutions of slow filters occurred. In comparison with influent, 16S rDNA sequencing revealed that phylotype diversity was low in the effluent of P- and C-filters, but no reduction was observed in the effluent of the B-filter. Suppressive potential of solutions filtered on a natural filter (C-filter), where the proportion of Proteobacteria (α- and β-) increased, whereas the proportion of uncultured candidate phyla rose in P- and B-filters, is discussed.
在无土栽培中，采用慢速过滤来消除营养液中的植物病原微生物。本研究聚焦于在番茄种植系统中，对经过整个 7 个月栽培季后，缓慢过滤器中回收的营养液中定植微生物群落的特征及其潜在功能进行研究。研究了在营养液经过过滤柱前后定植的细菌微菌群。两个过滤器分别添加了假单胞菌（P 过滤器）或蜡状芽孢杆菌（B 过滤器），第三个过滤器为对照（C 过滤器）。通过细菌添加对过滤单元进行生物激活，大大增强了过滤器对植物病原菌腐霉属和尖孢镰刀菌的防治效果。然而，在流出液中仍检测到大量细菌（10-10 CFU/mL）。群落水平生理分析表明，细菌微菌群的时间推移，以及营养液的代谢方向从最初的碳水化合物逐渐转变为氨基酸和羧酸的降解，这一过程在 7 个月的实验期间持续发生。单链构象多态性指纹图谱显示，慢速过滤器中定植于进水和出水的细菌群落之间发生了转移。与进水相比，P 和 C 过滤器的出水 16S rDNA 测序表明，细菌的多样性较低，但 B 过滤器的出水没有减少。讨论了自然过滤（C 过滤器）中过滤溶液的抑制潜力，在 C 过滤器中，α-和β-变形菌门的比例增加，而在 P 和 B 过滤器中，未培养候选门的比例上升。
