
Full text loading...
Category: Environmental Microbiology; Microbial Genetics and Molecular Biology
Molecular Basis of Biofilm Development by Pseudomonads, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555817718/9781555818944_Chap04-1.gif /docserver/preview/fulltext/10.1128/9781555817718/9781555818944_Chap04-2.gifAbstract:
Many of the tools for studying biofilms were developed in pseudomonads and, as such, these organisms have become a key model system for biofilm development by gram-negative bacteria. This chapter discusses what is known about biofilm development in pseudomonads and present working models of biofilm formation by these organisms. Cells are released from mature biofilms and reenter the planktonic state, making biofilm development a cyclic pathway in pseudomonads. Inorganic phosphate may be a key environmental factor required for biofilm formation by pseudomonads. Pseudomonas fluorescens and P. putida mutants lacking flagella have colonization defects on biotic surfaces, such as plant seeds and roots, and abiotic surfaces, such as sand, soil, plastic, and silicone. In P. aeruginosa, a complex between the virulence factor regulator (Vfr) and cAMP will form under glucose-limiting conditions. The study of the mechanisms of biofilm maintenance will likely be a fruitful area of investigation in the coming years. The chapter reviews what little is known about maintaining mature biofilm structure. A biofilm acts as reservoir for bacterial expansion in which successful colonization in one location subsequently permits surface exploration of numerous regions. The chapter discusses what is known about the biology of bacterial detachment. Insight into the biology of detachment will be a useful tool in the design of therapeutic agents for the fight against biofilm-based infections and for the disinfection of surfaces found in clinical and industrial settings.
Full text loading...
Model of biofilm development by pseudomonads. Planktonic cells (step 1) attach to the surface (step 2) first reversibly, then irreversibly, and start to develop microcolonies (step 3) either by aggregation of already attached cells, by recruitment of planktonic cells, or by clonal growth. These microcolonies then proliferate and mature (step 4) into a “mushroom shape” or a “carpet-like” biofilm, depending on environmental conditions and strain. Images were obtained during flow cell experiments by phase-contrast microscopy from a top-down view (magnification of ×630).
Model of biofilm development by pseudomonads. Planktonic cells (step 1) attach to the surface (step 2) first reversibly, then irreversibly, and start to develop microcolonies (step 3) either by aggregation of already attached cells, by recruitment of planktonic cells, or by clonal growth. These microcolonies then proliferate and mature (step 4) into a “mushroom shape” or a “carpet-like” biofilm, depending on environmental conditions and strain. Images were obtained during flow cell experiments by phase-contrast microscopy from a top-down view (magnification of ×630).
Summary of factors involved in biofilm development
Summary of factors involved in biofilm development