Surface and biofilms On surfaces microbial numbers and activity are usually much greater than in free water because of adsorption effects Bacteria grown on a glass slide immersed in a small river 八 Fluorescence photomicrograph of a natural microbial t community colonizing plant roots in soil
Surface and Biofilms On surfaces microbial numbers and activity are usually much greater than in free water because of adsorption effects. Bacteria grown on a glass slide immersed in a small river Fluorescence photomicrograph of a natural microbial community colonizing plant roots in soil
Biofilm Biofilms are encased microcolonies of bacterial cells attached to a surface by way of adhesive polysaccharides excreted by the cells; Functions: trap nutrients for growth of the enclosed microbial population and help prevent detachment of cells on surfaces in flowing systems Significance. in the human body, bacterial cells within a biofilm are made unavailable for attack by the immune system; dental plaque, a typical biofilm, contains acid-producing bacteria responsible for dental caries; In industry, biofilms can slow the flow of water or oil through pipelines, accelerate the corrosion of the pipes themselves
Biofilm Biofilms are encased microcolonies of bacterial cells attached to a surface by way of adhesive polysaccharides excreted by the cells; Functions: trap nutrients for growth of the enclosed microbial population and help prevent detachment of cells on surfaces in flowing systems; Significance: in the human body, bacterial cells within a biofilm are made unavailable for attack by the immune system; dental plaque, a typical biofilm, contains acid-producing bacteria responsible for dental caries; In industry, biofilms can slow the flow of water or oil through pipelines, accelerate the corrosion of the pipes themselves
Other factors affecting microbial ecology Nutrient levels and growth rates microbial competition and cooperation
Other factors affecting microbial ecology Nutrient levels and growth rates microbial competition and cooperation
Methods in Microbial Ecology Study biodiversity: isolation, identification and quantification of microorganisms in various habitats Study microbial activity Radioisotopes Microelectrodes
Methods in Microbial Ecology Study biodiversity: isolation, identification and quantification of microorganisms in various habitats. Study microbial activity: Radioisotopes Microelectrodes
Enrichment and isolation methods Enrichment culture technique: a medium and a set of incubation conditions are used that are selective for the desired organism and are counterselective for the undesired organisms The Winogradsky column: for isolation of purple and green phototrophic bacteria and other anaerobes From enrichments to pure cultures: Steak plate and agar shake tube method
Enrichment and Isolation Methods Enrichment culture technique: a medium and a set of incubation conditions are used that are selective for the desired organism and are counterselective for the undesired organisms. The Winogradsky column: for isolation of purple and green phototrophic bacteria and other anaerobes. From enrichments to pure cultures: Steak plate and agar shake tube method