MICB 202 Lecture Notes - Lecture 18: Biofilm, Stromatolite, Cyanobacteria
Document Summary
Bacterial communities have only been studied in earnest in the last 15 years. Previous studies were all done using pure cultures of free living, planktonic bacteria. Biofilms are ubiquitous, in terrestrial ecosystems and in the human body. Many, perhaps the majority of all bacteria, do not live alone but rather in communities. Two-thirds of bacterial infections encountered by physicians are due to biofilms. Biofilms are found on surfaces, edges, and bottoms of aqueous environments - they are one of the earliest forms of life on earth. Early biofilms include stromatolites, the oldest known fossils on earth, including oxygen pr- oducing cyanobacterium. Today, stromatolites on the bottom of pavilli- on lake are the largest known freshwater stromatolites. Biofilms were known to cause practical environmental problems. In recent years, we have learned that most bacteria in terrestrial e- nvironments live within interactive communities that sustain environ- mental ecosystems. Some human pathogens live in environmental biofilms.
