Bacteria grown in liquid medium are started with an inoculum (a few cells).
The cells show an initial slow growth (lag phase) followed by a period of rapid exponential growth (log phase) when the doubling time can be as short as 20 minutes.
Nutrients eventually become
limiting and cells enter the
A prototroph can synthesize all essential organic compounds and
can be grown on
minimal medium of carbohydrates and salts, while
an auxotroph has lost the ability to synthesize some compounds
which must be provided in the medium for the auxotroph to grow.