Cultural Methods

Culture techniques involving the diverse populations found in the environment are complexelsemps, and the numbers obtained depend on specific culture techniques. This chapter examines the techniques available for extraction and isolation of specific groups of microorganisms from soil and water. This is followed by plating methods that enhance the numbers of bacteria that can be cultured from soils, and new approaches for culturing members of the "soil rare biosphere." In addition, the "most probable number" technique is explained. Following this, the specific cultural methods for specific important groups of bacteria are presented including: heterotrophic plate counts; fecal coliforms via membrane filtration; Salmonella; fluorescent pseudomonads; the nitrifying bacteria; and 2,4-D degrading bacteria. Cultural methods for other types of microorganisms are also discussed including: fungi; algae and cyanobacteria; and viruses.