fermentation

Class : Biomass Technology and Production.
Lecture :  Pak Ngadiman
March, 24th 2015.

FERMENTATION

Fermentation have two meaning, first from "Microbiologist" and second from "Biochemist".
From Microbiologist, fermentation is any process for the production of a product by the mass culture of microorganism.
From Biochemist, fermentation is an energy generation process in which organic compound act as both electrons donor and acceptor that is anaerobic process.

Fermentation basis.
This is an picture of growth microorganism.

 

source : http://academic.pgcc.edu/~kroberts/Lecture/Chapter%206/06-20_MicrobialGrowth_L.jpg

There are four phase of growth microorganism.

From here, can determine, what the phase what you will take the result.

If you just need primary metabolite, so you just need the log phase. In these phase, the microorganism have higher activity. They will grow maximal. Primary metabolite is produce product for biomass cell. Example : If you need cellulose, you can take in log phase (middle until end phase).

But, if you need secondary metabolite, you must wait until stationary phase. Microorganism product secondary metabolite when they in stress environment so they produce that for survive their live. In stationary phase, the microorganism also have an sustainability about grow and death.

stationary phase > grow = death

Secondary metabolite that can produce in stationary phase is not for cell biomass of bacteria. Secondary metabolite also sensitive with external factors.