Microbiology Notes

Growth of Micro organisms:Pure culture of bacteria is needed to study their
Outcomes:characteristics.Single colonies are produced to know
In this article I will be discussing about bacterialwhether is pure or not.
growth.Methods of producing single colonies are
Microbial Growth: It can be defined as an increase in1. Streaking or spreading method
cellular constituents which may result in increase of2. Pour plate method.
size of the micro organism and its population number.Stages in a microbial growth:
Bacterial multiplication: bacteria multiply by binaryThere are four stages in microbial growth they are
fission, conjugation etc..,1. Lag phase
Binary fission is a method in which bacteria multiply in2. Log phase
doubles like from 1 to 2 and from 2 to 4 and 4-8 so3. Stationary phase
on.4. Death phase.
What do these bacteria grow on: Generally bacteriaTHE CONTINUOUS CULTURE OF MICRO
grow on a culture media. The culture media consistsORGANISMS:
of all the nutrient media required for growth.These are used to maintain the cells in exponential
Culture media: culture media can be of either liquid orgrowth phase at a constant biomass concentration
solid forms.for a extended period of time.
Liquid media: This can be solidified by addition of agar.There are two kinds of continuous, culture systems,
Agar is not a nutrient media; it is only a solidifyingchemostat and turbidostat.
agent.Bacterial growth can be defined as an increase in the
Pure culture:micro-organism's cell size or the population number.