Autolysis (biology)

In biology, autolysis, more commonly known as self-digestion, refers to the destruction of a cell through the action of its own enzymes. It may also refer to the digestion of an enzyme by another molecule of the same enzyme. The term derives from the Greek words αυτό ("self") and λύσις ("splitting").

Contents

Cell destruction

Autolytic cell destruction is uncommon in living adult organisms and usually occurs in injured cells or dying tissue. Autolysis is initiated by the cells' lysosomes releasing digestive enzymes into the cytoplasm. These enzymes are however released due to the cessation of active processes in the cell, not as an active process. In other words, though autolysis resembles the active process of digestion of nutrients by live cells, the dead cells are not actively digesting themselves as is often claimed and as the synonym self-digestion of autolysis seems to imply. Autolysis of individual cell organelles can be lessened if the organelle is stored in ice-cold isotonic buffer after cell fractionation.

Use

Because primate fetuses grow webbed fingers and toes, autolysis breaks down the webbing as they develop.

In the food industry, autolysis involves killing the yeast and encouraging the breakdown of the cells by enzymes. It is used to give different flavors. For yeast extract, when this process is triggered by the addition of salt, it is known as plasmolysis.[1]

In bread baking, the term (or, more commonly, its French cognate autolyse) is best described as the hydration rest following initial mixing of only flour and water that occurs before kneading has fully developed the gluten; this simplifies the shaping process of the finished dough.[2] The term was coined by French baking professor Raymond Calvel.

In the making of fermented beverages, autolysis can occur when the must or wort is left on the lees for a long time. In beer brewing, autolysis causes undesired off-flavors. Autolysis in winemaking is often undesirable, but in the case of the best Champagnes it is a vital component in creating flavor and mouth feel.[3]

See also

References

  1. ^ Kevin Kavanagh (2005). Fungi: biology and applications. Chichester: John Wiley & Sons. pp. 138–140. ISBN 0-470-86701-9. http://books.google.com/books?id=ERvSIh2EyT8C&pg=PA139#v=onepage&q&f=false. Retrieved 2010 Jul 25. 
  2. ^ Gisslen, Wayne (2009). Professional baking (5th ed.). New York: John Wiley. p. 136. ISBN 0-471-78349-8. 
  3. ^ J. Robinson (ed) "The Oxford Companion to Wine" Third Edition pg 54 Oxford University Press 2006 ISBN 0-19-860990-6