The polymer physics and chemistry of microbial cell attachment and adhesion
The polymer physics and chemistry of microbial cell attachment and adhesion
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DOI：
10.1039/b717046g
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发表时间：
2008-01-01
影响因子：
3.4
通讯作者：
Banwart, Steven A.
中科院分区：
文献类型：
--
作者：
Geoghegan, Mark;Andrews, Johanna S.;Banwart, Steven A.
微生物细胞附着在固体基质上是物种生存和群落内特定活动和功能发展的主要生态策略。从生物科学的角度提出了一个假说：微生物在界面上的附着是由细胞壁的大分子结构和诱导其生物合成的功能基因控制的，由此逻辑地得出这样的观点，即附着细胞的多样性是由这些大分子在界面区域和与其他细胞的物理和化学相互作用介导的。这方面可以简化为最简单的形式，将物理化学相互作用视为孤立细胞与固体或假固体基质之间的胶体力。这些力可以通过DLVO（Derjaguin，朗道，Verwey和Overbeek）理论中的既定方法进行分析。这样的方法几乎无法深入了解是什么控制了附着在表面上的细胞壁或其他细胞的行为变化。它也没有揭示任何光的驱逐大分子修改界面，如形成粘液层。这些物理和化学问题必须在细胞壁的各个组分的结构和行为的更基本水平上处理，例如生物表面活性剂和胞外多糖。这使我们能够在物理科学术语中重申上述假设：细胞附着和相关的细胞生长行为由界面环境中的大分子物理和化学介导。生态学的成功取决于遗传潜力，通过适应大分子结构，有利地影响界面。我们目前的研究，融合这两个角度。这是通过量化遗传多样性模型生物体的附着细胞生长，构建捕获界面结构变化的化学模型并量化所产生的物理相互作用来实现的。实验观察结合联合收割机水化学技术与表面光谱，以阐明细胞壁结构。原子力显微镜的方法量化的固体基质和细胞壁的关键成分，如大分子生物表面活性剂之间的物理相互作用。我们目前的方法侧重于考虑从细胞中收获的单个分枝菌酸或长链聚合物，以及表征的全细胞。这种方法允许我们使用多因素方法来解决与模型表面接触的细胞壁的各个组件的相对影响。然后，我们将这些组件联合收割机以逐步增加复杂性，同时与整个细胞的行为进行比较。最终，这种方法应该使我们能够估计和理解控制微生物细胞粘附的主要因素。虽然这项工作在基础层面上解决了细胞-矿物界面，但这项研究是由一系列技术需求驱动的。最初的基本原理是改进对自然环境（土壤、沉积物、含水层）中污染物降解的预测，以便进行环境清理。然而，这一研究领域涉及广泛的生物技术领域，包括提高对病原体存活的理解（例如，例如，在一个实施例中，在手术环境中），更好的生物制造过程强化（生物膜技术）和新产品开发。
The attachment of microbial cells to solid substrata is a primary ecological strategy for the survival of species and the development of specific activity and function within communities. An hypothesis arising from a biological sciences perspective may be stated as follows:The attachment of microbes to interfaces is controlled by the macromolecular structure of the cell wall and the functional genes that are induced for its biological synthesis.Following logically from this is the view that diverse attached cell behaviour is mediated by the physical and chemical interactions of these macromolecules in the interfacial region and with other cells. This aspect can be reduced to its simplest form by treating physico-chemical interactions as colloidal forces acting between an isolated cell and a solid or pseudo solid substratum. These forces can be analysed by established methods rooted in DLVO (Derjaguin, Landau, Verwey and Overbeek) theory. Such a methodology provides little insight into what governs changes in the behaviour of the cell wall attached to surfaces, or indeed other cells. Nor does it shed any light on the expulsion of macromolecules that modify the interface such as formation of slime layers. These physical and chemical problems must be treated at the more fundamental level of the structure and behaviour of the individual components of the cell wall, for example biosurfactants and extracellular polysaccharides. This allows us to restate the above hypothesis in physical sciences terms:Cell attachment and related cell growth behaviour is mediated by macromolecular physics and chemistry in the interfacial environment. Ecological success depends on the genetic potential to favourably influence the interface through adaptation of the macromolecular structure.We present research that merges these two perspectives. This is achieved by quantifying attached cell growth for genetically diverse model organisms, building chemical models that capture the variations in interfacial structure and quantifying the resulting physical interactions. Experimental observations combine aqueous chemistry techniques with surface spectroscopy in order to elucidate the cell wall structure. Atomic force microscopy methods quantify the physical interactions between the solid substrata and key components of the cell wall such as macromolecular biosurfactants. Our current approach focuses on considering individually mycolic acids or longer chain polymers harvested from cells, as well as characterised whole cells. This approach allows us to use a multifactorial approach to address the relative impact of the individual components of the cell wall in contact with model surfaces. We then combine these components to increase complexity step-wise, while comparing with the behaviour of entire cells. Eventually, such an approach should allow us to estimate and understand the primary factors governing microbial cell adhesion. Although the work addresses the cell-mineral interface at a fundamental level, the research is driven by a range of technology needs. The initial rationale was improved prediction of contaminant degradation in natural environments (soils, sediments, aquifers) for environmental cleanup. However, this area of research addresses a wide range of biotechnology areas including improved understanding of pathogen survival (e. g., in surgical environments), better process intensification in biomanufacturing (biofilm technologies) and new product development.