EXPERIMENTAL DESIGN FOR
IMPROVEMENT OF
FERMENTATIONSPLACKETT-BURMAN DESIGNS
JASMN LABORATORY,JERF
PERUNGUDI, CHENNAI- 97
• MICROBIOLOGIST
• MICROBE
– MEDIUM
– SET OF CONDITIONS
» TEMP
» pH
• METABOLITE/ACTIVITY OF INTEREST
– ANTIBIOTIC
– ANTICANCER AGENT
– ENZYMES
INTRODUCTION
• WE UNDERSTAND MANY THINGS IN
MICROBIAL PHYSIOLOGY AND
MOLECULAR BIOLOGY
• BUT IMPROVEMENT OF FERMENTATIONS
REMAINS LARGELY ON EMPERICAL
PROCESS
• THE RELEVANT LITERATURE AND PRIOR
TECHNIQUES SERVE ONLY AS A STARTING
POINT
• WHEN A NEW STRAIN IS ISOLATED AND THE
DETAILS OF IT IS NOT WELL KNOWN,
EMPERICAL APPROCHES TO FERMENTATION
IMPROVEMENT ARE THE ONLY WAY
• THESE ARE VERY COMMON IN INDUSTRIAL
SETTINGS
• EXPERIMENTAL DESIGNS AND STATISTICAL
ANALYSIS WILL HELP IMPROVE
FERMENTATIONS
• MICROBIOLOGIST
• MICROBIOLOGIST
STARTS WITH SOME
MEDIUM AND SET OF
CONDITIONS FOR THE
EXPRESSION OF
• MICROBE
– MEDIUM
METABOLITE OR
– SET OF CONDITIONS
ACTIVITY OF
» TEMP
INTEREST.
» pH
• METABOLITE/ACTIVITY
OF INTEREST
– ANTIBIOTIC
– ANTICANCER AGENT
– ENZYMES
• NEXT TASK IS TO IMPROVE
THE EXPRESSION TO A LEVEL
SUFFICIENT FOR THE
ISOLATION AND
CHARACTERIZATION OF THE
DESIRED PRODUCT
Fermentation improvement
programme- begins with
• Measuring the product • Classical method
yield
– One factor
– In response to factors
changed
at
a
time
• Medium strength
– Increase conc. by 25%
when others held
• Incubation temperature
constant
• Control of pH
• Replace original carbon and
nitrogen source
• Alternative source of P and S
may be considered
Example – single factorial design
• Microbe  Antibiotic
• Grown on 4%glucose + 2%
Soybean flour150 µg/ml
• First test for alternative
carbon source
• Glucose is replaced by
glycerol
• 2% glycerol+2% Soybean
flour 180 µg/ml
• Next Soy bean is
replaced by cotton
seed
• 4%glycerol + 2%cotton
seed  200 µg/ml
• Based on this further
study will be carried
out
NATURE OF THE STUDY
• THIS STUDY IS CALLED
• A FACTOR IS SAID TO BE
NONNUMERIC OR
CATEGORICAL IF ITS
CATEGORICAL: COTTON SEED/
FACTOR LEVELS OR
SOYABEAN
SETTINGS , REPRESENT
• ANOTHER STUDY IS KNOWN
DISJOINT ENTITIES WHICH
AS: NUMERICAL OR
FOLLOW NO NUMERICAL
CONTINUOUS
HIERARCHY
• 2%CS, 4%CS,8%CS ETC
• EX : COTTON SEED, SOY
• 2%SB,4%SB,8%SB,ETC
BEAN ETC
FULL FACTORIAL DESIGN
• WHEN CATEGORICAL FACTORS
NEED TO BE TESTED, A FULL
FACTORIAL IS THE EXPERIMENTAL
DESIGN OF CHOICE
• (EX: EFFECT OF Glucose, lactose,
NO3, NH3 ETC)
• AS THE NUMBER OF FACTORS
INCREASES, FULL FACTORIAL
DESIGN RESULTS IN EXESSIVELY
LARGE NUMBER OF
EXPERIMENTAL TRIALS
• MOST EXPERIMENTAL
SITUATIONS DEAL WITH
CONTINOUS FACTORS
WHICH ARE AMEABLE TO
SCREENING DESIGNS
REQUIRING FEWER TRIALS.
• EXPERIMENTS CONTAINING
BOTH CATEGORICAL AND
CONTINUOUS FACTORS
CAN BE DESIGNED
NUTRITIONAL FACTORS IMPORTANT IN COMMERCIAL FERMENTATION
FACTORS
RANGE OF FACTOR SETTING
{CON.% (WT/VOL)}
EXAMPLES
CARBON SOURCE(S)
0.5-20
GLUCOSE,SUCROSE, STARCH, WHEY
CORN MEAL, GLYCEROL, ALCOHOL,
LIPIDS
NITROGEN SOURCE(S)
0.1-10
AMMONIA GAS, AMM.SALTS,
CASEIN HYDROLYSATES, CORN
GLUTEN MEAL, CORN STEEP
LIQUOR, COTTON SEED FLOUR, FISH
MEAL, GLUTAMIC ACID, NITRATES,
PEPTONES, SOYBEAN FLOUR, UREA,
WHOLE YEAST, YEAST EXTRACT
PHOSPHORUS
0.1-2
CORN STEEP LIQUOR, PHOSPHATES
SULFUR
0.1-1
METHIONINE, PROTEINS,
SULFATES
OTHER NUTRIENTS
<1
Iron salts, Mg salts,
oxygen,K, trace elements,
vitamines
For further details
•Contact
•JASMN laboratory
•9444117141