Microorganisms Used in Food Fermentation ◾ 127
cheese, this aspect needs careful consideration. Pen. camembertii is used in Camembert cheese
and Pen. caseicolum is used in Brie cheese. They are also used to produce the enzyme glucose
oxidase.
Conclusion
Food-grade bacteria, yeasts, and molds are used in different combinations to produce several thousands of fermented foods worldwide by natural or controlled fermentation of milk, meat, fish, egg,
fruits, vegetables and others. The species and strains used as starter cultures in controlled fermentation should not only be safe and regulated but also be able to produce desirable characteristics in
the fermented foods. These characteristics are the result of metabolic breakdown of carbohydrates,
proteins, and lipids present in the food. Some of these are discussed briefly in Chapter 12 (also see
Chapter 8).
QUESTIONS
1. Discuss the criteria used to select a microorganism for beneficial purposes in foods.
2. List the different ways microorganisms are used beneficially in foods.
3. List the genera that are now included in the group of lactic acid bacteria.
4. List the genera currently used as starter cultures in food fermentation.
5. List one species each from Lactococcus and Streptococcus and two each from Leuconostoc,
Pediococcus, Bifidobacterium, and Propionibacterium used in food fermentation.
6. How are the species in genus Lactobacillus (the basis) divided into groups? List two species
from each group.
7. When are the following terms used: lactococci and Lactococcus; streptococci and Streptococcus;
leuconostocs and Leuconostoc; pediococci and Pediococcus; and lactobacilli and Lactobacillus?
8. Name three bacterial species that are now used as probiotic bacteria.
9. In yeast fermentation of different foods and beverages, only one species is used. Name the
species, and discuss how one species can be effective in so many fermentation processes.
Discuss the characteristics of bottom and top yeasts. Name a species that is now used commercially to produce β-galactosidase (lactase).
10. How are molds used in different ways in food? Name two species and list their uses. What
precautions are needed while using a mold strain in food fermentation?
References
1. Ray, B. and Daeschel, M.A., Biopreservatives of Microbial Origin, CRC Press, Boca Raton, FL, 1992.
2. Fox, P.F., Bacteria, beneficial | lactic acid bacteria: An overview. In Encyclopedia of Dairy Sciences (Second
Edition), John, W.F., Ed., Academic Press, San Diego, 2011, pp. 401–402.
3. Björkroth, J. and Koort, J., Lactic acid bacteria | taxonomy and biodiversity. In Encyclopedia of Dairy
Sciences (Second Edition), John, W.F., Ed., Academic Press, San Diego, 2011, pp. 45–48.
4. Schroeter, J. and Klaenhammer, T., Genomics of lactic acid bacteria, FEMS Microbiol. Lett., 292, 1–6,
2009.
5. Weimer, B.C., Lactic acid bacteria | physiology and stress resistance. In Encyclopedia of Dairy Sciences
(Second Edition), John, W.F., Ed., Academic Press, San Diego, 2011, pp. 56–66.
6. Toit, M., Engelbrecht, L., Lerm, E., and Krieger-Weber, S., Lactobacillus: The next generation of malolactic fermentation starter cultures: An overview, Food Bioprocess. Technol., 4, 876–906, 2011.
cheese, this aspect needs careful consideration. Pen. camembertii is used in Camembert cheese
and Pen. caseicolum is used in Brie cheese. They are also used to produce the enzyme glucose
oxidase.
Conclusion
Food-grade bacteria, yeasts, and molds are used in different combinations to produce several thousands of fermented foods worldwide by natural or controlled fermentation of milk, meat, fish, egg,
fruits, vegetables and others. The species and strains used as starter cultures in controlled fermentation should not only be safe and regulated but also be able to produce desirable characteristics in
the fermented foods. These characteristics are the result of metabolic breakdown of carbohydrates,
proteins, and lipids present in the food. Some of these are discussed briefly in Chapter 12 (also see
Chapter 8).
QUESTIONS
1. Discuss the criteria used to select a microorganism for beneficial purposes in foods.
2. List the different ways microorganisms are used beneficially in foods.
3. List the genera that are now included in the group of lactic acid bacteria.
4. List the genera currently used as starter cultures in food fermentation.
5. List one species each from Lactococcus and Streptococcus and two each from Leuconostoc,
Pediococcus, Bifidobacterium, and Propionibacterium used in food fermentation.
6. How are the species in genus Lactobacillus (the basis) divided into groups? List two species
from each group.
7. When are the following terms used: lactococci and Lactococcus; streptococci and Streptococcus;
leuconostocs and Leuconostoc; pediococci and Pediococcus; and lactobacilli and Lactobacillus?
8. Name three bacterial species that are now used as probiotic bacteria.
9. In yeast fermentation of different foods and beverages, only one species is used. Name the
species, and discuss how one species can be effective in so many fermentation processes.
Discuss the characteristics of bottom and top yeasts. Name a species that is now used commercially to produce β-galactosidase (lactase).
10. How are molds used in different ways in food? Name two species and list their uses. What
precautions are needed while using a mold strain in food fermentation?
References
1. Ray, B. and Daeschel, M.A., Biopreservatives of Microbial Origin, CRC Press, Boca Raton, FL, 1992.
2. Fox, P.F., Bacteria, beneficial | lactic acid bacteria: An overview. In Encyclopedia of Dairy Sciences (Second
Edition), John, W.F., Ed., Academic Press, San Diego, 2011, pp. 401–402.
3. Björkroth, J. and Koort, J., Lactic acid bacteria | taxonomy and biodiversity. In Encyclopedia of Dairy
Sciences (Second Edition), John, W.F., Ed., Academic Press, San Diego, 2011, pp. 45–48.
4. Schroeter, J. and Klaenhammer, T., Genomics of lactic acid bacteria, FEMS Microbiol. Lett., 292, 1–6,
2009.
5. Weimer, B.C., Lactic acid bacteria | physiology and stress resistance. In Encyclopedia of Dairy Sciences
(Second Edition), John, W.F., Ed., Academic Press, San Diego, 2011, pp. 56–66.
6. Toit, M., Engelbrecht, L., Lerm, E., and Krieger-Weber, S., Lactobacillus: The next generation of malolactic fermentation starter cultures: An overview, Food Bioprocess. Technol., 4, 876–906, 2011.