Examples of helpful bacteria:
Lactobacillus Bacteria: There are several different species of this type of bacteria. These include: Lactobacillus acidophilus, Lactobacillus reuteri, and Lactobacillus planatarum. They are gram-positive, rod shaped bacteria. Lactobacillus bacteria are beneficial in several ways:
- They make up parts of the normal human oral, intestinal, and vaginal flora.
- They are able to ferment lactose to lactic acid. This makes them important as a preservative and in yogurt production.
Streptomyces Bacteria: There are several different species of this type of bacteria. These include: Streptomyces aureofaciens, Streptomyces rimosus, and Streptomyces griseus. They are gram-positive, filamentous bacteria. Streptomyces bacteria are beneficial in the following ways:
- They are important in the decomposition of organic substances in soil.
- Some species are used in the production of antibacterial and antifungal substances.
Examples of harmful bacteria:
Helicobacter pylori: These bacteria colonize the lining of the stomach. They are gram-negative rod shaped bacteria. H. pylori bacteria cause stomach ulcers by producing ammonia and cytotoxins which damage the lining of the stomach.
Clostridium tetani: These bacteria enter the body through wounds. They are gram-negative rod shaped bacteria. These bacteria produce the disease tetanus. Tetanus causes muscle spasms and death from respiratory failure.