The food industry has taken advantage of the ability of microbes to produce a number of important, commercially available foods. Live and active bacterial cultures cause pasteurized milk to ferment producing yogurt. Bacterial cultures also ferment fruits and vegetables, according to European Bioinformatics Institute.
Yogurt
Yogurt contains two active cultures: Lactobacillus bulgaricus and Streptococcus thermophilus, probiotics or live microorganisms similar to good bacteria in the human gut. Some yogurts undergo heat treatment after culturing, which kills the live and active cultures, but does not affect taste, or decrease calcium, protein or other nutrients, and helps in preservation.
To identify yogurt containing live and active cultures, the National Yogurt Association established a voluntary special Live & Active Cultures seal; consequently, some yogurts containing live and active cultures may not have the seal.
Cheese
The following bacteria produce cheeses: Lactobacilli, including Lactobacillus acidophilus, Lactococci, or Streptococci. Swiss cheese cultures add Propionibacter shermani, which produces carbon dioxide during aging, giving Swiss cheese its holes.
Olives
According to the journal "Scientific Commons," as stated by Dr. Mourad Kacem, twenty-two isolates of lactic acid producing bacteria ferment olives, including: Lactobacillus plantarum, Lactobacillus lactus, and Enterococcus. Without fermentation, olives would be bitter and inedible.
Pickles
Brining cucumbers begins with the addition of a salt solution. Cucumber fermentation uses lactic acid-producing bacteria, which gives pickles a sour taste and prevents growth of harmful bacteria. During fermentation, the cucumbers are held in 5 percent to 8 percent salt; after fermentation, salt concentration increases weekly to a final strength of 8 percent to 16 percent. According to the journal "Applied Microbiology," as stated by Dr. J. L. Etchells, bacteria used include: Enterobacter aerogenes, Lactobacillus brevis and L. plantarum, Leuconostoc mesenteroides and Pediococcus cerevisiae.
References
- European Bioinformatic Institute: Bacteria Genomes - LACTOBACILLUS ACIDOPHILUS
- National Yogurt Association: Live & Active Culture Yogurt
- Environmental Protection Agency: Pickles, Sauces and Salad Dressings,
- PubMed Central: Pure Culture Fermentation of Green Olives, Dr. J. L. Etchells;1966
- Scientific Commons: Isolation of Lactic Acid Bacteria from Naturally Fermented Algerian Olives; 2005
