1. BPE PPT

2. TOPIC:{1}. KINETICS OF GROWTH LINKED PRODUCT FORMATION
{2}. SIGNIFICANCE OF

3. Product formation kinetics fall into one of the following three types:
[1]. Growth associated product formation
[2].Non- growth associated product formation
[3].Mixed mode product formation

4. Pirt (1975) has discussed the kinetics of product formation by microbial cultures in terms of -growth linked products -non growth linked products The formation of growth linked product may be described by the equation; dp/dt = qpX ❶ Where p= concentration of product qp= specific rate of product formation

5. Also,
Product formation is related to biomass production by the equation;
dp/dx = Yp/x ❷
Where,
Yp/x = yield of product in terms of biomass
Now,
multiply equation 2. by dx/dt
Then,
dx/dt . dp /dx = Yp/x. dx/dt
And
dp/dt= Yp/x. dx/dt
But

6. dx/dt = µx and therefore;
dp /dt = Yp/x. µx
And
dp/dt= qp .x
And therefore,
qp .x =Yp/x .µx ,
qp = Yp/x . µ ❸
From equation 3,
It may be seen that when product formation is growth associated the specific rate of product formation increases with specific growth rate.
Thus,
Productivity in batch culture will be greatest at µmax and improved product output will be achieved by increasing both µ and biomass concentration.

7. [1].GROWTH LINKED PRODUCT FORMATION - growth linked products are formed by growing cells and hence primary metabolites This figure clearly shows that product is formed simultaneously with growth of cells. That is product concentration increases with cell concentration.

8. Non GROWTH LINKED PRODUCT FORMATION -They are formed by cells which are not metabolically active And hence are called secondary metabolites. This figure clearly shows that product formation is unrelated to growth rate but is a function of cell concentration

9. Mixed mode product formation It takes place during growth and stationary phases In this graph, product formation is a combination of growth rate and cell concentration

10. Substrate utilization constant
Significance of
Substrate utilization constant

11. Ks is the substrate utilization constant , numerically equal to substrate concentration
When, µ is half µmax and is a measure of the affinity of the organisms for its substrate.

12. If the organism has
-High affinity -Growth rate will not be affected -Deceleration phase would be short
-Low affinity -Growth rate will be affected -Deceleration phase would be relatively long.

13. thankyou