Fermentation biotechnology

slide prepared for student benefit

1. INDUSTRIAL FERMENTATION BIOTECHNOLOGY
Dr.Kalaiselvigovindan
Animal Biotechnology
TANUVAS, INDIA

2. Fermentation technology
•Food safety is a global issue
•Soil microbes can spoil food
•Contamination by unsanitary handling of
food
•Improper storage and preparation
procedures can lead to contamination by
pathogens
•Imports of fruits and vegetables from 3
rd

World countries can bring in diseases and
parasites
•*Hands washed properly??

3. Bread Production
•Sourdough culture- yeast Candida milleri and
Lactobacillus sanfrancisco 1:100 ratio
•German sour rye bread has 4 different yeast
species and 13 species of Lactobacilli
•Yeast feed on the sugars except maltose,
Lactobacilli need maltose, then produce ethyl
alcohol and CO2
•Lactobacilli produce lactic and acetic acids
giving the sour flavor, pH 3.6 - 4.0 inhibits
microbial growth

4. GRAINS
•Rye and wheat are harvested dry
•If they get wet, molds and other microbes will grow
•Insect, birds and rodent vectors also transmit
microbes
•Raw grain with mold Claviceps purpurea cause
ergotism, mold is halucinogenic and deadly
•Aspergillus produce aflatoxins
•Rhizopus nigricans is most common bread mold,
also Aspergillus, Penicillium and Monila (pink mold)
•Rye bread likely infected by Bacillus sp (w/spores)

5. FRUITS AND VEGETABLES
•Pseudomonas fluorescens are found on surface of
fruits and vegetables
•Pathogens: Salmonella, Shigella, Entameoba,
Ascaris can be transmitted on surfaces
•Leafy vegetables more susceptible to rot by Erwinia
carotovora, Penicillium mold on citrus fruits and
apples
•Fungus Phytophthora infestans caused potato blight
•Now using GMO to make plants resistant
•Tomato rot- Fusarium fungus, Rhizopus injected by
insects. Peach rot - Monilia fruiticola

6. MEATS AND POULTRY
•70 different types pathogens found at
slaughterhouses, inspected by vet
•Dec 2003 -1
st
case of Mad Cow in US, stricter laws
•Carcasses are hung in refrigerated rooms to age,
some mold: Rhizopus and Mucor , Pseudomonas
release H2S and green coloration
•Clostridium cause bone stink deep in carcass
•Ground meat- may have helminths-Trichinella,
lactobacilli, salmonella, E.coli
•Should be cooked to kill pathogens

7. FISH AND SHELLFISH
•Fresh fish have microbes: enteric bacteria,
worms, & viruses which survive even
shipped in ice
•Shellfish- oysters & clams –Salmonella and
Vibrio
•Clams filter feeder can pick up red tides
toxins, sewage
•Shrimp (breaded) have high bacterial counts
•Lobster and crabs - enteric pathogens
•Crabs carry Clostridium, Cryptococcus and
Candida

8. MILK
•Breeding cattle for high milk production have
large udders and easily admit bacteria- get
rid of 1
st
few squirts which can have 15,000
bacteria /ml
•Mostly Staphylococcus, Micrococcus,
Pseudomonas
•Hand milking- E. coli, Acinetobacter
•Diseased cattle can transmit Mycobacterium
bovis Brucella, TB
•Milk is Soured by Streptococcus lactis,
Lactobacillus

9. OTHER EDIBLE
SUBSTANCES
•Sugar- raw cane supports fungi: Aspergillus,
Saccharomyces, Candida. Bacteria: Bacillus
and Micrococcus
•Clostridium causes the bulge in cans
•High sugar concentration acys as
preservative
•Maple trees are tapped in spring
-Leuconostoc , and Enterobacter
•Honey toxins for Clostridium spores-floppy
baby syndrome botulism

10. PREVENTING DISEASE TRANSMISSION
AND FOOD SPOILAGE
•More contamination in large processing plants
•Klebsiella found in human digestive tract is also a
respiratory pathogen, but can cause diarrhea
•TB can be transmitted from unpasteurized
milk/cheese
•Virus are transferred through food
•Milk is ideal medium for growth of
pathogens/microbes
•Crucial factor to prevent spoilage and disease is
cleanliness in handling, use fresh foods, refrigerate,
•Process quickly and store properly

11. Methods of preservation of food
•Drying of grain
•Osmotic pressure (salt or sugar)- Dried and
salted meats and other foods
•Fermentation - milk allowed to sour was
made into cheese
•Canning - use of moist heat under pressure,
used to preserve fruits, vegetables, meats in
glass jars and metal cans.
Destroys microbes, endospores, prevents
spoilage

12. CANNING
•Some thermophiles ( Bacillus
stearothermophilus) may remain alive
even after canning, spores can
germinate and grow, can will bulge in
heat (thermophilic anaerobic spoilage)
•Flat sour spoilage
•Mesophilic spoilage- improper canning
at room temp
•Sugars

13. Food canning

14. Commercial Sterilization to Destroy
C. botulinum Endospores
•12D treatment kills 10
12
endospores
•Surviving endospores of thermophilic
anaerobes cause spoilage with gas
or flat-sour spoilage

15. DRYING AND LYOPHILIZATION
•Drying- desication or dehydration is oldest
method
•Remove 90% of water
•Stops growth but does not kill microbes
•Can be sun dried, heated in ovens etc
•Addition of slat, sugar or chemicals also
used
•Lyophilization- freeze drying is used for
instant coffee and dry yeast for bread making

16. Food Preservation- Irradiation
•Aseptic packaging:
Pre-sterilized
materials assembled
into packages and
aseptically filled.
•Gamma radiation kills
bacteria, insects, and
parasitic worms.
•High-energy electrons

17. FOOD IRRADIATION- Ionizing Radiation
•2 types of Irradiation- UV
and Ionizing
•Still new and controversial
•Microwaves do not kill, but
the heat is microbicidal, but
food must be rotated
•Ionizing-Gamma Rays can
penetrate and are
microbicidal
•Can be done, before or after
packaging
•Cobalt 60 gamma and Cs
137 used in Japan and
Europe, FDA has declared
safe in the US
•USDA proposed rules for
irradiation of fresh poultry..
Still a debate!

18. CHEMICAL ADDITIVES
•Benzoic, sorbic and propionic acids used in
margarine, juice, bread, other baked goods
•Alkylating agents- ethylene oxide used on
nuts/spices
•Ozone used on shellfish
•NaCl- salt to cure meats, dehydrates bacteria
•Halogen, chloride for processing equipment
•Nitrates on sausage, hot dogs
•QUATS- sanitize udders, fresh vegetables,
eggshell surfaces

19. ANTIBIOTICS
•In US only nisin - bacteriocin produced by
milk fermentation by Streptococcus lactis
•Antibiotics are prohibited because: (p 790)
•Antibiotic resistance

20. PASTUERIZATION OF MILK -
STANDARDS
•2 methods :
• High temp short time
•Low temp long time
•Ultra high temperature- UHT treatment
•Some chemical additives
•Milk and Food in US carefully regulated by
FDA
•Animals inspected and soon stricter methods
by microscope
•Quality control has many tests for purity and
guarantees high quality milk to consumers

21. MICROORGANISMS AS FOOD
AND IN FOOD PRODUCTION
•Algae, Fungi, and Bacteria as Food:
•Yeasts are good source of protein
•1 kg yeast = 100 kg protein, but human
digestive tract can only handle small
amounts of it
•Algal cultures: Cyanobacteria- Spirulina and
red algae grown in aquaculture (in Kona)
•Algae- ingredient of ice cream
•Yeast, algae and bacteria could increase
World Food Supply!

22. FOOD PRODUCTION: BREAD &
DAIRY
•BREAD- previous slide on sour dough
•Yeast Saccharomyces is a leavening agent, produce
gas ato make bread rise and alcohol by fermentation
•Alcohol and CO
2
driven off during baking- holes
•DAIRY- cultured buttermilk- Streptococcus cremoris
is added to skim milk and allowed to ferment, also
Leuconostoc sp
•Sour cream- add one of above microbes to cream
•Yogurt- Streptococcus and Lactobacillus added to
milk

23. FOOD PRODUCTION: DAIRY
•Fermented Milk beverages- Mongolia- Arak drink
from Mare’s milk produces alcohol
•Acidophilus milk- add Lactibacillus acidophilus
•Bulgarian milk- add L. bulgaricus, makes it more
acidic
•Kefir- Balkan goats milk stored in goatskin bags
•Koumiss- Russian drink from Mare’s milk
•Streptococcus lactis, L. bulgaricus, and yeasts are
responsible for lactic acid, alcohol and other
products

24. Cheese
•Curd: Solid casein from
lactic acid bacteria and
rennin
•Whey: Liquid separated
from curd
•Hard cheeses produced
by lactic acid bacteria
•Semisoft cheeses ripened
by Penicillium on surface

25. OTHER PRODUCTS
•Vinegar: ethyl alcohol by Acetobacter aceti
•Sauerkraut: cabbage with salt and microbes
Lactobacillus and Leuconostoc ferment under
anaerobic conditions
•Pickles: add brine to cucumbers and ferment
•Olives: ferment in Salt and Leuconostoc
•Poi: ferment taro paste, yeast adds alcohol
•Soy Sauce: soybeans, salt and Aspergillus-ferment
•Soy Products: Miso, Tofu soft curd
•Fermented Meats: salami, bologna, summer sausage

26. Alcoholic Beverages-Beer, Wine
and Spirits
•Distillation-
•Beer and ale are fermented starch.
•Malting: Germinating barley converts
starch to maltose and glucose.
•Yeast ferment sugars to ethyl alcohol +
CO
2

28. Yeast Fermentations

29. Making Red Wine

30. Microbial Metabolism
Sugar Ethyl alcohol + CO
2
Saccharomyces cerevisiae
Malic acid Lactic acid
Lactic acid bacteria
Ethyl alcohol Acetic acid
Acetobacter or Gluconobacter

31. Fermentation Technology

32. Primary Fermentation

33. Secondary Fermentation

34. •Amino acids
•Citric acid
•Enzymes
•Vitamins
•Antibiotics :
•Penicillum
•Steroids
Industrial Microbiology/Pharmaceutical
Microorganism

35. Useful Organic Products
•Simple Organic Compounds-
•Antibiotics-1940’s penicillin, 2% are marketed, others are too
toxic, semi-synthetic antibiotics - augmentin
•Enzymes-used in industrial processes
•Proteolytic enzymes in coated granules are added to
detergents
•Enzymes in paper production-lignin digested by fungi
•Amino acids-8 of 20 essential aa not synthesized by us
•Need lysine, glutamic acid etc
•Bioconversion-steroids, insulin, cortisone, progesterone

36. Microbiological Mining:
Biological Leaching of Copper Ores

37. Alternative Energy Sources Using
Microorganisms
•Bioconversion-----methane or ethyl alcohol

38. Microbiological Waste Disposal
•Sewage treatment plants
•Bioremediation- use of microbes to
dispose of chemical wastes
•3 strains of microbes can Deactivate
Aroclor 1260- a toxic PCB
•Others detoxify cyanide and dioxin
•Use GMO microbes