Biofilm development and cell death in the marine bacterium Pseudoalteromonas tunicata
Biofilm development and cell death in the marine bacterium Pseudoalteromonas tunicata
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DOI：
10.1128/aem.70.6.3232-3238.2004
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发表时间：
2004-06-01
影响因子：
4.4
通讯作者：
Kjelleberg, S
中科院分区：
文献类型：
--
作者：
Mai-Prochnow, A;Evans, F;Kjelleberg, S
新描述的绿色细菌被膜假交替单胞菌（D2）产生针对细菌，藻类，真菌和无脊椎动物幼虫的靶向特异性抑制化合物，并且经常与海洋环境中的生物表面相关联。作为我们对被囊藻生态学及其与海洋表面相互作用研究的一部分，我们在实验室内连续培养条件下研究了被囊藻形成生物膜的能力。被衣青霉生物膜表现出由水道包围的分化小菌落组成的特征结构。值得注意的是，我们观察到在被衣假单胞菌生物膜形成过程中细胞死亡的可重复模式，类似于最近报道的铜绿假单胞菌生物膜（J.S. Webb等人，J. Bacteriol. 185：4585-4595，2003）。杀伤和溶解发生在小菌落内，显然导致这些结构内形成空隙。在生物膜中的杀伤区域内总是观察到活细胞的亚群。此外，成熟生物膜中的广泛杀伤似乎导致生物膜从基质中脱离。一种新的190-kDa的自毒蛋白产生的被膜，命名为AlpP，被发现参与这种生物膜的杀伤和脱离。产生了被膜假单胞菌的DeltaalpP突变体衍生物，并且该突变体在生物膜发育期间不显示细胞死亡。我们建议，AlpP介导的细胞死亡中起着重要的作用，多细胞生物膜的发展和随后的扩散中幸存的细胞在海洋环境中的被囊对虾。
The newly described green-pigmented bacterium Pseudoalteromonas tunicata (D2) produces target-specific inhibitory compounds against bacteria, algae, fungi, and invertebrate larvae and is frequently found in association with living surfaces in the marine environment. As part of our studies on the ecology of P. tunicata and its interaction with marine surfaces, we examined the ability of P. tunicata to form biofilms under continuous culture conditions within the laboratory. P. tunicata biofilms exhibited a characteristic architecture consisting of differentiated microcolonies surrounded by water channels. Remarkably, we observed a repeatable pattern of cell death during biofilm development of P. tunicata, similar to that recently reported for biofilms of Pseudomonas aeruginosa (J. S. Webb et al., J. Bacteriol. 185:4585-4595, 2003). Killing and lysis occurred inside microcolonies, apparently resulting in the formation of voids within these structures. A subpopulation of viable cells was always observed within the regions of killing in the biofilm. Moreover, extensive killing in mature biofilms appeared to result in detachment of the biofilm from the substratum. A novel 190-kDa autotoxic protein produced by P. tunicata, designated AlpP, was found to be involved in this biofilm killing and detachment. A DeltaalpP mutant derivative of P. tunicata was generated, and this mutant did not show cell death during biofilm development. We propose that AlpP-mediated cell death plays an important role in the multicellular biofilm development of P. tunicata and subsequent dispersal of surviving cells within the marine environment.