This document discusses biotransformation, which is a chemical reaction catalyzed by living cells or enzymes. It can be used to modify the functional groups of organic compounds. The document outlines some prerequisites for successful biotransformation processes, including the culture having the necessary enzymes and the substrate not being toxic. It also discusses using plant cell and organ cultures, immobilized cell cultures, and genetic engineering approaches for biotransformation. Some factors that influence biotransformation are also summarized.
1. BIOTRANSFORMATION
PRESENTED BY :
SRISHTI AGGRAWAL
M.SC BOTANY
1702443
FACULTY OF SCIENCE
DEI,AGRA
PRESENTED TO :
Dr.P.K DANTU
FACULTY OF SCIENCE
DEI,AGRA
2. INTRODUCTION
Biotransformation is a chemical reaction
catalysed by cells ,organs or enzymes.
It is defined as a process through which the
functional groups of organic compounds are
modified by living cells to a chemically
different product.
It explores the unique properties of
biocatalysts, namely their stereo region
specificity and their their ability to carry out
reactions at no extreme pH values and
temperature.
3. It may be used to carry out specific
conversions of complex substrates using
plant,animal or microbial cells or purified
enzymes as catalysts.
The production of metabolities ,fine
chemicals and pharmaceutical can be
achieved by biotransformation using
biological catalysts.
4. For a successful and viable process,the
following prerequisites must be met.
The culture must have the essential
enzymes.
The substrate must not be toxic to the cell
culture.
The substrate must reach the appropriate
cellular compartment of the cell.
The rate of product formation must be
faster than its further metabolism.
5. BIOTRANSFORMATION USING PLANT CELL AND
ORGAN CULTURES.
The biotransformation rates on a variety of
factors:-
The amount of enzyme activity present,
localization of enzymes,
Elicitation,
Permeability,
pH variation,
osmotic effects
Some eg: Peganum harmala cell culture
converted geranyl acetate to geranitol and linalyl
acetate to linalool and terpinol.
6. BIOTRANSFORMATION USING IMMOBILIZED
CELL CULTURE
Entire cells offer the chance to implement
multistep biotransformation and to utilize and
recycle essential cofactors and coenzymes
Isolated enzymes may be sensitive to
denaturing conditions including pH,heat and
specific organic solvents.
In order to be useful in biotransformation
reactions, biocatalysts need to be stable and
reusable.
Use of whole cell immobilized system may help
overcome some stability problems
7. Immobilized plant cells have some additional
advantages over freely suspended cells; they
are more resistant to shear damage and can
be used repeatedly over a prolonged period.
Complete cell immobilization may also create
adverse conditions under which secondary
metabolite production may be improved.
A very common method for immobilization of
plant cells are gel entrapement by ion
exchange, precipitation, polymerization .
8. GENETIC ENGINEERING APPROACHES
Biotransformation capacity of cell cultures can be
further improved by changing the following
parameters:-
1) Cell selection
2) Elicitation
3) Permabilization
4) Radiation
5) pH of medium
6) Osmotic shock
A more basic approach is transfer of genes that code
for the key enzymes catalyzing the desired biosynthetic
reactions into a fungal or bacterial cell because their
ability to produce high amounts of enzymes (Pras et
al,1995)
9. Hashimoto et al,1993 explain the
expression of hyoscyamine 6-b-hydroxylase
in E.coli. This recombinant bacterium was
capable to convert hyoscyamine to
scopoamine.
Subsequently, this cloned gene has been
transferred to Atropa belladonna and
expressed constitutively.
10. ADVANTAGES OF BIOTRANSFORMATION
Production of novel compound
Improvement in the productivity of
desired compound
Overcoming the problems relates with
chemical synthesis.
11. FACTORS INFLUENCING BIOTRANSFORMATION
Improvement of cell viability
Many substances are harmful to cultured
cells. So it is necessary to decrease the
toxicity in order to increase the yield of the
product.
Sugar can increase cell viability during
glycosylation of phenolic compounds.
Antioxidants can improve cell viability and
increase product formation in the
biotransformation of phenolics.
12. Selection of plant species
Tabata et al (1988) reported that among 7 sp.
Of plant cell cultures , only Dathura had
capacity to biotransforme flavonoids,
phenolic acids and anthraquinones.
Immobilized plant cells
It has distinct advantages e.g.reuse of the
expensive biocatalyst, continuous process,
and process control is simplified.
13. Root culture
Cell suspension culture has excellent
biotransformation capacity for glycosylation.
Furuya et al (1989) have found that the root
culture showed higher glycosylation activity
than cell culture.