Culturing of microbes to degrade pollutant

1. Fiza Tariq and Maryam Bashir
Roll No:23,28
Botany semester(7)
Biodegradation and Bioremediation
Design Of Enrichment
Strategies relating to
the Environmental
Source

2. Enrichment strategies:
Enrichment strategies focus on
creating an environment that favours
growth of specific microorganisms
from collected environmental
sample. These microbes can then be
used for various purposes, including
bioremediation. Here’s breakdown of
down process.

3. Target application:
Identify the desired outcome of
using microbes .This could be
bioremediation, food production or
industrial application.

4. Environmental sample collection:
Consider factor like the location
and type of environment the
microbes are expected to come
from. For example collecting soil
sample from compost pile or water
sample from hot spring.

5. Enrichment Culture:
Enrichment culture is basically an
isolation technique designed to make
conditions of growth very favourable
for an organism of interest while
having an unfavourable environment
for any competition.

6. Enrichment Strategies:
Five Stages:
1. Selection and sampling of
environment.
2. Pre-treatment of samples
3. Growth in laboratory media
4. Incubation
5. Isolate selection.

7. Selection and Sampling of
environment:
The objective for exercising care
in the choice of sampling site is to
increase chance of finding the
desired microbe.
 E.g. thermophilic microbes are
more likely to be isolated from
geothermal sites than from
environments that are not heated.

8. Thermotolerant microbes are also
present in temperate soil but
there are more chances of finding
it in geothermal sites.
The objective is to manipulate the
microbes environment in such a
way as to select and isolate most
effective organisms from within
more microbial population of
selected samples.

9. Selection is desired towards the
gene pool present in the
environment sample.
Under such system the best is
determined at physiological level
by the expression of phenotypic
traits already present in members
of microbial population in the
sample.

10. Pre-treatment:
Now the next stage is to pre-treat the
sample before culturing.
The microbial populations are
subjected to dilution or concentration
to selective inhibitory treatments.
E.g. heat treatment in order to kill all
vegetative cells for isolating only
spore producing microbes.

11. UV irradiations can be used to
select for cyanobacteria.
After it, samples are used.
The sooner the samples are used
after collection, the more
environmentally representative
they will be.

12. Growth in lab media:
The next step is to culture the
sample in lab media.
There these samples are provided
with desired nutritional and
growth requirements to get
desired traits.
Special inhibitors are incorporated
into medium to prevent growth of
undesirable groups of organisms.

13. The presence of antibiotics in the
medium can select against
bacteria in fungal enrichment
strategies and selection can be
further enhanced by reducing PH
of medium.

14. Incubation:
The period of incubation is of
considerable importance, with
accepted period ranging from few
days of thermophilic bacteria to
several months for detection of
nitrifying bacteria.

15. Bacterial isolation strategies
usually involves period of
enrichment in liquid culture
followed by spatial separation of
organisms in or on solid media
where they are allowed to grow as
colonies.
Isolate selection:

16. Spatial separation of components
of consortium of microbes may
restrict metabolic exchange so
preventing sufficient metabolism
of substrate to support growth of
consortium.

17. When using solid media in enrichment
and selection strategies, microbes
when attached to surfaces , are
capable of growth in presence of low
nutrient level as consequence of
surface concentration effect which
may translate into an enhanced
ability to degrade recalcitrant
molecules.

18. THANK YOU