FOOD FROM MICROORGANISMS:

FUNGI, BACTERIA AND FERMANTATION

OBJECTIVES

• To recall the method of nutrition used by microorganisms

• To know some examples of commercial exploitation of microbial metabolism

What is heterotroph?

herbivores

carnivores

omnivoresAll

animals

Most bacteria

Some fungi

MICROBES CARRY OUT USEFUL METABOLIC PROCESSES

• Heterotrophic

• Fungi -such as yeast and Fusarium- and many bacteria saprotrophic

• The enzymes, toxic or excess products which they excrete of use to humans

• Some microbes useful in food production

• Acetobacter vinegar manufacture

• Lactobacillus yoghurt and cheese production

• ‘Ripening’ bacteria cheese production

• Fusarium and mycoprotein

• On an enormous scale in special factories

• The microbes

cultured separately added sterilised container

These containers

fermenters or bioreactors

• ÖZNUR WILL <3

Commercial Food Production

• The fermentation processes used to grow the microbes must be economical and efficient, and methods are always being improved.

• Cheese production is a traditional process that has been updated by the use of modern scientific techniques.

• The curds are formed more quickly if the coagulation of the milk protein casein is catalysed by an enzyme.

• Traditionally rennin was used, extracted from the stomach contents of calves slaughtered for meat.

• Genetic engineers have now produced a strain of the bacterium E.

• Coli which contains the gene for the enzyme chymosin.

• This enzyme can be used instead of rennin to produce a cheese that is acceptable to vegetarians.

• The second phase of cheese production also involves the action of bacteria or fungi – hard cheeses such as Stilton are formed by bacterial action from the inside, whereas soft cheeses are usually the result of fungal action from the outside.

• The characteristic smells of strong cheeses are usually due to metabolism of fatty acids, sometimes the same as those found on human skin.

• The warm, moist conditions on the feet produce and odour which the producers of Camembert cheese call ‘les pieds de dieu’ (God’s feet).

• Bread and beer are produced using yeast to ferment a sugar source.

• NİSA WILL

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Bacteria the production of foodVinegar aerobic fermantation of alcohol

references

• http://www.biology-online.org/dictionary/Heterotroph

• COMPLETE BIOLOGY FOR IGCSE