Nutrient agar is used in laboratory experiments as a culture medium for growing microorganisms. Commercial agar is extracted from certain types of red-purple marine algae. You can also make your own nutrient agar with beef or chicken broth. Many different types of bacteria and some fungi can grow on a nutrient agar plate. With a properly prepared nutrient agar dish, you can grow a wide variety of microorganisms. Microorganisms can be pathogenic, or disease-causing, harmless, or beneficial. Follow safety procedures when handling agar dishes with microorganisms, because some can cause diseases.
Some types of bacteria in the genus bacillus can be grown on nutrient agar. The genus bacillus contains many bacteria. Bacillus are aerobic, which means they can grow in the presence of oxygen. Bacillus megaterium, bacillus stearothermophilus, and bacillus subtilis are a few types of bacteria that can grow on a nutrient agar plate.
Streptococcus can grow on nutrient agar. Some streptococcus cause diseases, but some are beneficial. Streptococcus lactis, also called Lactococcus, is a microbe that ferments milk sugar to lactic acid. It is found in grasses and in milk. It is used in the manufacturing of cheese and fermented milk. Other examples of Streptococcus that grow on nutrient agar include Streptococcus thermophilus and Streptococcus faecalis, also called Enterococcus.
Escherichia coli, also called E. coli, is an anaerobic bacterium found in the gastrointestinal tract of most warm-blooded animals. It is not harmful to its host. When fecal matter containing E. coli gets into drinking water, it can cause disease. Escherichia coli grows on nutrient agar.
The Kingdon Funi includes many organisms. Fungi break down dead organic material and function as nutrients for plants. Some fungi cause diseases in humans, such as ringworm and athlete's foot. Saccharomyces diastaticus and Sporobolomyces sp. are two types of fungi that grow on nutrient agar.
- Science Buddies: All About Agar
- Todar's Online Textbook of Bacteriology: Bacillus and Related Endospore-forming Bacteria
- NCBE: Recommended Bacteria
- Todar's Online Textbook of Bacteriology: Featured Microbe: Lactococcus Lactis
- Todar's Online Textbook of Bacteriology: Pathogenic E. coli
- UCMP Berkeley: Introduction to the Fungi
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