Microbes in agriculture

1. BIO 304 Microbiology
Read the newspaper lately?
Microorganisms affect our daily lives in many ways….
Canada geese can be winged couriers of so-called superbugs
Horses to be vaccinated for EEE and WNV
Staph infections latest threat to athlete’s health
Human gut microbes associated with obesity
Clean water and food: what is acceptable risk?
Bad teeth correlated with heart disease and others
Environmental change and infectious disease

2. …they affect us so much that…
At the turn of the new millenium,
Time magazine declared…
• The 20th Century was the Age of Physics
and…
• The 21st Century will be
the Age of Biotechnology
Dr. Kary Mullis
Dr. Albert Einstein

3. The objects of study…
A microbiologist may study any one of these groups
Kingdom Prokaryota
*eubacteria
*cyanobacteria
*archaebacteria
Kingdom Protoctista
*protozoa
*algae
*slime/water molds
Kingdom Fungi
*bread molds
*yeasts and sac fungi
*mushrooms
Kingdom Animalia
*Invertebrates
*Vertebrates
Kingdom Plantae
*spore-bearing plants
*seed bearing plants

4. Yet, it’s mainly bacteria, viruses, and fungi
that we study in Microbiology….
• Microorganisms (microbes) are able to grow,
generate energy, and reproduce in a single cell.
• Specifically, they have the ability to:
– metabolize most food (organic/carbon) sources
– withstand the range of Earthly…
• temperatures
• atmospheric pressures
• osmotic pressures
• pH ranges
• Most plant and animals exist as multi-cellular
organisms.

5. This course is mainly about bacteria.

6. The study of microbiology is a
bit different!
• Microbiology = the study of microscopic life
~versus~
• Botany- the study of plants
• Zoology- the study of animals
• Procedures & practices are quite different -
look for biochemical and genetic differences
– Therefore microbiology has developed
independently of zoology & botany.
Bacteria and viruses are referred to by STRAIN

7. Where can we find MO’s
and in what forms?
• Microbes and the Biosphere
- Air ~ 100,000 feet (19 miles)
- Soil ~ 1,700 feet
- Water ~ 34,000 feet (6.5 miles)
Photo from ASM

8. Microbial ubiquity…
• Microorganisms (MO’s) exist everywhere!
– In soil, water, and air
– In/on your skin, hair, oral cavity,
gastrointestinal tract
– Outnumber our cells by more than 10:1 in/on our body!
• Yet, we’re barely aware that they exist.
We become aware when we become sick or notice
spoiled or damaged goods.
• less than 0.01% of bacteria cause disease.
Most are beneficial to man and other life forms.

9. However, negative affects on
mankind…
• Historic:
– Bubonic Plague- wiped out ~25% of Europe in 4
years (1347-1351)….prelude to Renaissance???
– Syphilis – not recorded in Europe until after
Columbus and crew returned from New World
– Irish Potato Blight- >1 million starved causing mass
migration to US/other countries (1870’s)
– Civil War and WW1-more soldiers died from disease
and infection than from gunshot wounds
– Malaria, Dengue fever, and other human parasites
significant impact on central region of Africa

10. Affects to mankind cont’d….
• Modern day:
Emergent and re-emergent diseases:
– 1974: Discovery of Lyme Disease agent
– 1976: Discovery of Legionnaires’ Disease agent
– 1978: Toxic Shock Syndrome caused by bacterial toxins
– 1983: Discovery of HIV infecting human T cells
– 1985: Multi-drug resistant Mycobacterium tuberculosis
– 1993: Hanta/Ebola hemorrhagic virus
– 1999: West Nile virus
– 2002: MRSA and VRSA seen in hospitals in Canada
– 2003: SARS virus
– ????: H5:N1 Influenza virus (Bird-flu virus)
In every case, new problems have created new areas of study –
with the creation of new technologies.
In fact, over 50% of all Rx antibiotics come from soil bacteria.

11. Still, the overwhelming majority of
microbes are beneficial to mankind!
Microorganisms aid in:
• Environmental recycling
• Mining
• Agriculture
• Human health
• Biotechnology
• Food/beverage industry

12. Microbes and Agriculture…
• Certain soil bacteria live symbiotically in the
roots of legumes (N2-fixing bacteria)
-convert inert N2 gas into amines
• Mycorrhizal fungi
-provide increased N, P, K, and antibiotics!
• Ruminant bacteria of cattle, sheep benefit
these animals in metabolizing cellulose

13. Microbes and the Food Industry
• Foods made directly with aid of microbes
Cheeses (bleu, camembert, Roquefort, brie),
yogurt, breads, vinegars, soy sauce, sweeteners
• Most all foods are indirectly aided by
microbial activity (vegetables and meat
commodities)
• Fermented beverages - $60 Billion/year (US)
• Bacteria provide high quality protein…
SCP! in the future???

14. Energy related industries
involving microbes
• Natural gas (methane) is a product of bacterial
action
– Will be discussed in Archaebacteria section
• Methanogens
• Crude oil is a product of prehistoric microbial
photosynthesis. Also, crude oil can be degraded
by bacteria
– Drilling *All of these require
– Recovery methods which minimize
– Storage microbial contamination.

15. Mineral and energy related
industries involving microbes
• This is a $200 Billion industry per year.
• Refuse piles These may be converted to
• Landfills “biofuels”
• Surplus grain
• Now, metal recovery from low-grade ores
– Fe and Cu
– Reduced ions as a result of microbial
metabolism

16. Recombinant MO’s can mass produce
substances related to human health
• Insulin- hormone which lowers blood
sugar; used by diabetics
• Interferon- class of cytokines effective vs
viral infections
• Factor VIII- blood protein necessary for
clotting; missing in hemophiliacs
• Streptokinin - bacterial enzyme to dissolve
blood clots in coronary arteries
• Beta endorphins- pain suppressors

17. Microbes and Biotechnology
“Bacteria invented the biotech industry…”
• Taq polymerase used for PCR amplification of DNA (from
Thermus aquaticus)
• Genes can be excised from DNA, using microbial enzymes as
precise tools – restriction enzymes
• Bacterial plasmids can be used to inject genes or altered DNA
into host cells - transformation
• Bacteria can be genetically modified to mass produce a wide
assortment of products
• Microbes are the “hammers and nails” of biotechnology!!

18. Microbes are critically
important!!!
“The role of the infinitely small
is infinitely large. ”
-Louis Pasteur (1869)