Pseudomonas aeruginosa PAO1 preferentially grows as aggregates in liquid batch cultures and disperses upon starvation.
Pseudomonas aeruginosa PAO1 preferentially grows as aggregates in liquid batch cultures and disperses upon starvation.
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DOI：
10.1371/journal.pone.0005513
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发表时间：
2009
期刊：
影响因子：
3.7
通讯作者：
Kjelleberg S
中科院分区：
文献类型：
--
作者：
Schleheck D;Barraud N;Klebensberger J;Webb JS;McDougald D;Rice SA;Kjelleberg S
在自然和人工环境中，细菌主要生长在生物膜中，细菌通常以自由悬浮的单细胞形式从生物膜中分散出来。在本研究中，我们仔细研究了铜绿假单胞菌在间歇培养液中浮游细胞聚集体或“悬浮生物膜”的形成和扩散，并将其与间歇培养液中以聚酯（PE）纤维为固体表面的基质上生物膜的形成进行了比较。采用激光衍射粒度扫描（LDA）和聚集体显微镜对浮游生物样品进行了分析。有趣的是，LDA表明，在生长阶段，高达90%的浮游生物总生物量由直径在10-400µm范围内的细胞聚集体组成，而不是单个细胞。在PE表面的培养中，铜绿假单胞菌倾向于在生物膜中生长，而不是浮游生长。然而，在碳、氮或氧限制下，浮游生物聚集体和pe附着的生物膜分散到单个细胞中，导致光密度（OD）的增加，而不依赖于细胞的生长。在生长过程中，浮游聚集体和pe附着的生物膜含有密集堆积的活细胞和细胞外DNA (eDNA)，饥饿导致活细胞的损失，死亡细胞和eDNA的增加。此外，在分散培养中观察到代谢物和感染性噬菌体释放到培养上清中，细胞内第二信使环二gmp浓度显著降低。因此，传统上被描述为浮游的，铜绿假单胞菌的单个细胞培养，实际上是悬浮的生物膜，这种聚集体具有类似于表面相关生物膜的行为和反应（例如扩散）。此外，我们认为该浮游生物膜模型系统可以为铜绿假单胞菌同步生物膜生命周期的详细分析提供基础。
In both natural and artificial environments, bacteria predominantly grow in biofilms, and bacteria often disperse from biofilms as freely suspended single-cells. In the present study, the formation and dispersal of planktonic cellular aggregates, or ‘suspended biofilms’, by Pseudomonas aeruginosa in liquid batch cultures were closely examined, and compared to biofilm formation on a matrix of polyester (PE) fibers as solid surface in batch cultures. Plankton samples were analyzed by laser-diffraction particle-size scanning (LDA) and microscopy of aggregates. Interestingly, LDA indicated that up to 90% of the total planktonic biomass consisted of cellular aggregates in the size range of 10–400 µm in diameter during the growth phase, as opposed to individual cells. In cultures with PE surfaces, P. aeruginosa preferred to grow in biofilms, as opposed to planktonicly. However, upon carbon, nitrogen or oxygen limitation, the planktonic aggregates and PE-attached biofilms dispersed into single cells, resulting in an increase in optical density (OD) independent of cellular growth. During growth, planktonic aggregates and PE-attached biofilms contained densely packed viable cells and extracellular DNA (eDNA), and starvation resulted in a loss of viable cells, and an increase in dead cells and eDNA. Furthermore, a release of metabolites and infective bacteriophage into the culture supernatant, and a marked decrease in intracellular concentration of the second messenger cyclic di-GMP, was observed in dispersing cultures. Thus, what traditionally has been described as planktonic, individual cell cultures of P. aeruginosa, are in fact suspended biofilms, and such aggregates have behaviors and responses (e.g. dispersal) similar to surface associated biofilms. In addition, we suggest that this planktonic biofilm model system can provide the basis for a detailed analysis of the synchronized biofilm life cycle of P. aeruginosa.
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细菌外多糖产生所需的环状-DI-GMP受体。
影响因子：
3.6
作者：
Lee, Vincent T;Matewish, Jody M;Kessler, Jennifer L;Hyodo, Mamoru;Hayakawa, Yoshihiro;Lory, Stephen
通讯作者：
Lory, Stephen
DOI：
10.1038/ismej.2008.109
发表时间：
2009-03
期刊：
The ISME journal
影响因子：
--
作者：
Rice SA;Tan CH;Mikkelsen PJ;Kung V;Woo J;Tay M;Hauser A;McDougald D;Webb JS;Kjelleberg S
通讯作者：
Kjelleberg S
影响因子：
3.6
作者：
Fakhruddin, A. N. M.;Quilty, B.
通讯作者：
Quilty, B.
影响因子：
3.6
作者：
Allesen-Holm, M;Barken, KB;Tolker-Nielsen, T
通讯作者：
Tolker-Nielsen, T
影响因子：
3.8
作者：
APPLEGATE, DH;BRYERS, JD
通讯作者：
BRYERS, JD