Microbial fermentation By Aneela Saleem

Microbial fermentation is one of the aspect the Human Welfare.

2. Introduction.
Fermentation media.
Industrial microorganisms.
Types of fermentation.
Batch fermentation.
Fed-Batch fermentation.
Growth rate.
Continuous fermentation.
Effect of flow rate on substrate concentration.
Important factors for continuous fermentation.
Recent advances in microbial fermentation
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3. Fermentationis ametabolicprocess that
produces chemical changes in
organicsubstratesthrough the action
ofenzymes.
In the context of food production, it may more
broadly refer to any process in which the activity
ofmicroorganismsbrings about a desirable
change to a foodstuff or beverage.The science
of fermentation is known aszymology.
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5. The fermentation industry is composed of
five major bio-ingredient categories.
They are:
-Proteins & amino acids.
-Organic acids.
-Antibiotics.
-Enzymes.
-Vitamins & hormones.
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6. Fermentation industry is driven by:
-The cost and availability of feed-stocks.
-The efficiency of industrial microorganism.
-Fermentation condition and optimization.
-Down stream process and end-product
recovery efficiency.
-Fermentation by-product utilization.
-Utility consumption and labor cost.
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7. Optimum balance of the media is mandatory for cells
propagation and for the maximum production of
target metabolite (end-product).
Media compositions:
-Carbon source.
-Nitrogen source.
-Minerals.
-Growth factors.
-Precursors (mutants).
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8. Microbial screening.
-Wild strains.
Microbial yield improvement
-Mutation.
-Recombinant DNA.
-Genetically engineered.
Microbial selection.
Industrial microorganism
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93 C
43 C
21 C
4 C

9. Solid State fermentation (SSF).
Liquid State fermentation (LSF) Surface
culture & submerged culture
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10. SSF process can be defined as microbial
growth on particles without presence of
free water.
Particles are a solid culture substrate such
as rice or wheat bran saturated with water
and inoculated with (mold, yeast, bacteria)
in controlled room temperature.
It is ideal for growing filamentous fungi.
It has been used in Asia and developing
nations.
It is more cost effective (smaller vessels
lower water consumption, reduced waste
water treatment costs, lower energy
consumption, and less contamination
problems).
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11. Applications:
Potentially many high value products
such as extra-cellular enzymes,
primary metabolites, and antibiotics
could be produced in SSF.
It is estimated that nearly a third of
industrial enzyme produced is made
by SSF process.
Production of organic and ethanol
from starchy substrates.
Digestibility of fibers and
lignocelluloses materials for both
human and animal consumption.
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12. -Submerged culture is performed in tanks which can reach in size
for over 100,000 gallons.
-It is ideal for the growing unicellular organisms such as bacteria
and yeast.
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13. Considered to be a closed system.
The sterilized media in the fermenter is
inoculated with the microorganism.
Incubation is allowed under the optimum
conditions (aeration, agitation,
temperature).
During entire fermentation nothing is
added except air, antifoam and acid/base.
Production of Penicillin via Batch Fermentation
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Batch fermentation

14. It is enhancement of batch fermentation.
Continue adding the nutrients (feeding) in a
small doses during the fermentation.
The method in controlling nutrients feeding
process is by measuring methods.
The main advantage of fed-batch fermentation is
the elimination of catabolite repression (feed-back
inhibition).
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17. It is an open system.
Continuously sterile nutrient is added and the converted
nutrient is taken out from the fermentor.
In continuous process cell loss as a result of outflow must be
balanced by growth of the microorganism.
Production of Citric Acid via Continuous
Fermentation
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The relationship between biomass (X), the concentration of limiting nutrients (C) ,and
the dilution rate (D) are important factors in continuous

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20. The system must be stable for at least 500
hours.
Maintaining sterile conditions for all period of
fermentation time.
The composition of nutrients must be constant
all the time.
Maintaining the strain stability for constant high
production yield (concerning about reverse
mutation).
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21. Semi-continuous fermentations, in
which a fraction of a fermentation is
replaced with fresh media at regular
intervals.
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22. There arethree basic
formsof fermentation:
Lactic acidfermentation;
whenyeastsand bacteria
convert starches or sugars
into lactic acid
infoodslikepickles, yoghurt
and sourdough bread.
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23. Ethyl alcoholfermentation; where
thepyruvate moleculesin starches
or sugars are broken down by
yeasts into alcohol and carbon
dioxide molecules to
producewineand beer.
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24. Acetic acidfermentation of starches or sugars
from grains or fruit into sour tasting vinegar and
condiments(add flavourto food). This is the
difference, for example, betweenapple cider
vinegar and apple cider.
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25. Each of these kinds of
fermentation is down to the
work ofmicrobesspecialized at
converting certain substances
into others.
Fermentation's Key Ingredients:
Microbes!
Fermentation is all down to the
actions of tinynatural microbes,
who colonize and cultivate
everything from ourdigestive
systems, to this colorful spring
in Yellowstone seen in the
picture,to the food and drink
we eat.
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27. LAB
Lactic acid bacteria (LAB) are the major bacteria
used in food fermentations worldwide.
LAB consist of a myriad of genera including, but not
limited to, Lactobacillus, Lactococcus,
Streptococcus, Leuconostoc, Pediococcus, and
Enterococcus.
Though the LAB are a diverse group of bacteria,
many species enjoy historical “generally regarded as
safe” (GRAS) and “qualified presumption of safety”
(QPS) status by the Food and Drug Administration
(FDA) and European Food Safety Authority (EFSA),
respectively.
LAB fermentation has long been recognized to
confer beneficial effects on human health through
the modulation of the intestinal microbiota.
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Fermentation starters can produce a number of desirable and undesirable
bioactive metabolites.
1.Biogenic amines
(left) are an undesirable product in most fermentations due to their toxicity.
2.Bioactive peptides
(right) produced through enzymatic release are desirable by-products due to
positive biological activity.
3.Bacteriocins
(centre) are desirable as a known
probiotic trait, but potentially undesirable
in a starter culture due to possible impact
on other fermenting cultures.

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33. Microbial fermentation holds the key to some
extremely complex interactions between
bacterial species and the food matrix they are
fermenting.
These microbial fermentations in a more
knowledge-based fashion than that of the past.
With regard to microbial fermentation in food,
this represents an area with potential well
beyond the extension of shelf life.
The work in these areas is continuing and,
with the help of better regulation, could lead to
exciting new discoveries on managing disease
symptoms through food.
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34. http://www.biotechnologynotes.com/industrial-biotechnology/fermentation-
process/fermentation-types-8-types-of-fermentations-industrial-biotechnology/13695
https://f1000research.com/articles/6-751
EFSA Panel on Biological Hazards (BIOHAZ): Update of the list of QPS-
recommended biological agents intentionally added to food or feed as notified to
EFSA 4:Suitability of taxonomic units notified to EFSA until March 2016. EFSA
Journal. 2016; 14(7): e04522
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