Cardiff School of Biosciences, Cardiff University, Cathays Park, Cardiff, Wales.
Adv Microb Physiol. 2009;56:29-84. doi: 10.1016/S0065-2911(09)05602-1. Epub 2009 Nov 26.
Microorganisms can form tightly knit communities such as biofilms. Many others include marine snow, anaerobic digester granules, the ginger beer plant and bacterial colonies. This chapter is devoted to a survey of the main properties of these communities, with an emphasis on biofilms. We start with attachment to surfaces and the nature of adhesion. The growing community then forms within a matrix, generally of organic macromolecules. Inevitably the environment within such a matrix is different from that outside. Organisms respond by forming crowd-detection and response units; these quorum sensing systems act as switches between planktonic life and the dramatically altered conditions found inside microbial aggregates. The community then matures and changes and may even fail and disappear. Antimicrobial resistance is discussed as an example of multicellular behavior. The multicellular lifestyle has been modeled mathematically and responded to powerful molecular biological techniques. Latterly, microbial systems have been used as models for fundamental evolutionary processes, mostly because of their high rates of reproduction and the ease of genetic manipulation. The life of most microbes is a duality between the yin of the community and the yang of planktonic existence. Sadly far less research has been devoted to adaptation to free-living forms than in the opposite direction.
微生物可以形成紧密结合的群落，如生物膜。还有许多其他的群落，包括海洋雪、厌氧消化颗粒、姜啤酒植物和细菌菌落。本章专门介绍了这些群落的主要特性，重点介绍了生物膜。我们从附着在表面和粘附的性质开始。然后，生长中的群落形成在基质中，通常是有机大分子。这样的基质内的环境不可避免地与外部环境不同。生物体通过形成群体感应和响应单元来做出反应；这些群体感应系统充当浮游生物生活和微生物聚集体内明显改变的条件之间的开关。然后，群落成熟并发生变化，甚至可能失败和消失。抗菌耐药性被作为多细胞行为的一个例子来讨论。多细胞生活方式已经通过数学模型进行了模拟，并对强大的分子生物学技术做出了响应。最近，微生物系统被用作基本进化过程的模型，主要是因为它们具有很高的繁殖率和易于遗传操作。大多数微生物的生命是群落的阴和浮游生物存在的阳之间的双重性。可悲的是，与相反方向相比，对自由生活形式的适应的研究要少得多。
