Kitchen Microbiology

Biotechnology – Use of Microbes

Your understanding of Microbes

What is a microbe?

Where do you find them?

Are they beneficial or harmful?

Microbes in the Kitchen

   Microbes or MO (microorganisms) are a part of our everyday life.

What did you eat yesterday? List them in your notebook. Let see if any of your food is made by our tiny friends (MOs).

Commonly Known

   Cheese/Butter – Fermentation lowers the pH, thus helping in the initial coagulation of the milk protein, as well as giving characteristic flavors. ( Some of the bacteria used in cheese fermentation is found in smelly feet Streptococcus and Lactobacillus bacteria) Bread provides a variety of enzymes that enable carbohydrates to be broken down producing sufficient carbon dioxide to give bread its characteristic texture.

cerevisiae) (Baker’s Yeast - S accharomyces Beer especially Traditionally, the natural yeasts on grape skins determine the quality of wine produced. These natural yeasts, Saccharomyces cerevisiae (beer in Spanish is "cervesa") and Saccharomyces ellipsoideus , ferment the grapes to make wine.

Coffee/ Cocoa (chocolate)

   Bacteria and yeast are used to remove the outer coats of coffee.

Erwinia dissolvens , leuconostoc , and lactobacillus species, Saccharomyces The microbes do not affect the taste of coffee but are necessary to confer the characteristic taste to cocoa and chocolate.

Soy sauce/Vinegar

  Soy sauce/Miso made from a mixture of soy beans and rice fermented by a variety of bacteria and fungi. Lactobacillus delbrueckii , Aspergillus oryzae , Aspergillus soyae , and Saccharomyces rouxii . Vinegar Vinegar is made by two distinct biological processes, both the result of the action of harmless microorganisms (yeast and “Acetobacter”) that turn sugars (carbohydrates) into acetic acid.

The first process is called alcoholic fermentation and occurs when yeasts change natural sugars to alcohol under controlled conditions. In the second process, a group of bacteria (called “Acetobacter”) converts the alcohol portion to acid.

Vitamins/MSG

   Microbes may be used to elaborate precursors in the making of Vitamins A, C, and the B family. Using sugarbeet molasses as a growth medium, Pseudomonas denitrificans produce Vitamin B12. Members of the genus Propionibacterium (B2), the fungus is made to are also used to make this vitamin. Although many bacteria and fungi produce riboflavin Ashbya gossypii produces it in huge quantities. MSG (monosodium glutamate) is manufactured by Corynebacterium glutamicum , a cousin of the diptheria germ. The fungus, Aspergillus niger grown on sugarbeet molasses, produces huge quantities of citric acid. , when

Amino Acids

   Citric acid used to be extracted primarily from lemons, but worldwide demand for it forced the commercial industry to seek other sources. The fungus, Aspergillus niger sugarbeet molasses, produces huge quantities of citric acid. , when grown on Glutamic acid requires Corynebacterium glutamicum formation. Biotin is a cofactor essential for lipid synthesis in bacteria. By growing C. glutamicum biotin, it causes the bacterial membrane to leak sufficient quantities of glutamic acid. Lysine -- The bacterium, flavum for its on limited amounts of Brevibacterium is used in the industrial biosynthesis of lysine. Mutants no longer susceptible to feedback inhibition have been isolated to be used industrially to increase the yield of amino acids.

Meat Products

 Meat products, like salami and bologna sausages, require some fermentation with Pediuococcus cerevisiae , Lactobacillus plantarum and some members of the genus Bacillus . Country cured hams use fungi of the genus Aspergillus and the genus Penicillium in their fermentation process. Izushi (sushi), a Japanese delicacy made from a mixture of fish, rice, and other vegetables is produced by fermentation with lactobacilli.

Pickled Food

  Dill pickles are simply fermented cucumbers. Streptococci starts the process of fermentation, but as the pH level falls, leuconostoc and pediococcus species, as well as Lactobacillus plantarum continue the process. Olives are edible only after fermentation with Lactobacillus plantarum and Lactobacillus mesenteroides .

Homework

  Find one thing at home that is made by microorganism. On a puzzle piece   Front: place a picture of the product, write the name of the MO and the ingredient produced by the MO.

Back: your name, period, and date