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BATCH CULTURE
 It is a closed culture
system which contains an
initial limited amount of
nutrients.
 Bacteria will grow until
necessary growth factor
becomes exhausted and
becomes limiting.
 No additional nutrients
are added to the closed
system called as batch
culture.
Batch culture divided into 4 phases
CONTINUOUS CULTURE
This is an open process in which microbial cultures also
grow continuously in log phase.
The exponential growth in batch cultures can be
prolonged by the addition of more substrate but it will
lead to the overflow device is fitted to the fermentor
such that the added medium displace an equal volume
of culture from the vessel than the continuous
production of the cell is achieved such types of system
are called as continuous culture .
DIFFERENCES
BATCH CULTURE CONTINUOUS CULTURE
It is a closed culture system
which contain an initial limited
amount of nutrients.
It is open culture system where
nutrients are continuously fed.
 Batch culture undergo
four phases i.e., lag , log
,stationary ,decline.
 The change in cell
biomass can be
represented as follows :
dx =µx
dt
 Exponential phase can be
prolonged by the
addition of fresh
nutrients.
 The change in cell
biomass can be
represented as follows :
dx=µx ̶ dx
dt
The chances of
contamination are less.
 The chances of
The Biomass productivity
represented as follows:
Rbatch =xmax - x
ti- tii
 The biomass productivity
The productivity is
maximum only towards
the end of the process.
contamination are more.
represented as follows:
Rconti=dx[1-tiii]
T
If operated at optimum
diluted rate under steady
state conditions productivity
is always constant and
maximum
The culture requirements
 The culture requirement
vary during the process i.e,in remains constant i.e.,
the beginning oxygen
constant amount of
requirement and agitation
oxygen and agitation is
requirement is less and as
required during the
process proceed due to the
process.
increase in the cell density
.oxygen demand and
agitation requirement
increases .
Extensive labour is
required throughout the
Extensive labour is required
the process.
only at the start and end of
the process.
The growth curve is
sigmoidal.
The growth curve is j
shaped.
They can not be easily
scaled up.
They can be easily scaled
up.
The effect of unproductive
time i.e.,tiii is more.
The effect of unproductive
time i.e., tiii is less.
 Simple control. it is easier
to control reaction
conditions
(ph,pressure,temperature.).
 Complex control automatic
control must be used .control
of reactor conditions is more
difficult .control must be
exercised over the rate of
flow of the material.
Preferable when production
of small quantities of specific
material are planned .
Extraction of material only
after all the actions are
finished with the conclusion
of reaction.
Production of primary
metabolites only.
Examples : alcohol ,amino
acids etc .
Growth ,product formation
and substrate utilization all
terminate after a certain time
interval.
Preferable for
production.
large
scale
continuous
extraction
of
products at all times during the
reaction.
Production of primary as well as
secondary
metabolites.
Examples: antibiotics.
Growth and product formation
can be maintained for prolonged
periods of time .
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