Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, ESMISAB, Université Européenne de Bretagne/Université de Brest, 29280, Plouzané, France.
Microb Ecol. 2012 Jan;63(1):170-87. doi: 10.1007/s00248-011-9961-1. Epub 2011 Oct 21.
In recent years, increasing the level of suppressiveness by the addition of antagonistic bacteria in slow filters has become a promising strategy to control plant pathogens in the recycled solutions used in soilless cultures. However, knowledge about the microflora that colonize the filtering columns is still limited. In order to get information on this issue, the present study was carried out over a 4-year period and includes filters inoculated or not with suppressive bacteria at the start of the filtering process (two or three filters were used each year). After 9 months of filtration, polymerase chain reaction (PCR)-single strand conformation polymorphism analyses point out that, for the same year of experiment, the bacterial communities from control filters were relatively similar but that they were significantly different between the bacteria-amended and control filters. To characterize the changes in bacterial communities within the filters, this microflora was studied by quantitative PCR, community-level physiological profiles, and sequencing 16SrRNA clone libraries (filters used in year 1). Quantitative PCR evidenced a denser bacterial colonization of the P-filter (amended with Pseudomonas putida strains) than control and B-filter (amended with Bacillus cereus strains). Functional analysis focused on the cultivable bacterial communities pointed out that bacteria from the control filter metabolized more carbohydrates than those from the amended filters whose trophic behaviors were more targeted towards carboxylic acids and amino acids. The bacterial communities in P- and B-filters both exhibited significantly more phylotype diversity and markedly distinct phylogenetic compositions than those in the C-filter. Although there were far fewer Proteobacteria in B- and P-filters than in the C-filter (22% and 22% rather than 69% of sequences, respectively), the percentages of Firmicutes was much higher (44% and 55% against 9%, respectively). Many Pseudomonas species were also found in the bacterial communities of the control filter. The persistence of the amended suppressive-bacteria in the filters is discussed with regards to the management of suppressive microflora in soilless culture.
近年来，通过在慢滤器中添加拮抗细菌来提高抑制水平已成为控制无土栽培中再生溶液中植物病原体的一种有前途的策略。然而，关于定植在过滤柱中的微生物区系的知识仍然有限。为了获取这方面的信息，本研究进行了 4 年，包括在过滤过程开始时接种或不接种抑菌细菌的过滤器（每年使用两到三个过滤器）。过滤 9 个月后，聚合酶链反应（PCR）-单链构象多态性分析指出，对于同一年的实验，对照过滤器的细菌群落相对相似，但在添加细菌的过滤器和对照过滤器之间存在显著差异。为了描述过滤器内细菌群落的变化，通过定量 PCR、群落水平生理谱和 16SrRNA 克隆文库测序（第 1 年使用的过滤器）对该微生物群进行了研究。定量 PCR 证明，与对照和 B 过滤器（接种了蜡状芽孢杆菌菌株）相比，P 过滤器（接种了铜绿假单胞菌菌株）的细菌定植密度更高。功能分析集中在可培养的细菌群落上，结果表明，对照过滤器中的细菌比添加了细菌的过滤器中的细菌代谢更多的碳水化合物，而添加了细菌的过滤器中的细菌的营养行为则更针对羧酸和氨基酸。P-和 B-过滤器中的细菌群落的多样性和明显不同的系统发育组成都明显高于 C-过滤器。尽管 B-和 P-过滤器中的变形杆菌数量远低于 C-过滤器（分别为 22%和 22%，而不是 69%的序列），但厚壁菌门的比例要高得多（分别为 44%和 55%，而 9%）。在对照过滤器的细菌群落中也发现了许多假单胞菌属。本文讨论了添加抑菌细菌在过滤器中的持久性，以期管理无土栽培中的抑菌微生物。
