Environmental Microbiology and Biotechnology

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ENVI7001 Environmental Science and Industrial Hygiene

Environmental Microbiology and
Biotechnology

What can microorganisms do?


How can we use this to our advantage?

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Environmental Microbiology


the study of the composition and physiology of microbial
communities in the environment.

Functions in Natural Environments

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Environmental Microbiology


the study of the composition and physiology of microbial
communities in the environment.

1.
Decomposing organic substrates.

2.
Serving as a food source for protozoa, nematodes and
soil insects.

3.
Modifying substances for use by other organisms.

4.
Producing inhibitory compounds that decrease microbial
activity.

5.
Biodegradation of waste.

Functions in Natural Environments

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene


-

Virtually
every environmental niche


-

Extremes
of pH and salinity


-

Extremes
of temperature and pressure


-

Without
air (Anaerobic)


-

Growth
on many chemical substrates


-

Attached
to surfaces in biofilms


-

Geothermal
vents and subterranean deposits

Microorganisms found in Diverse Environments

Environmental Microbiology

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Biogeochemical Cycling



Biological and chemical processes involved in the cycling
and transformation of nutrients.



Matter can neither be created or destroyed.



A constant amount of matter in the environment must be
recycled.



Microbes are essential in the conversion of nutrients into
organic and usable formats and into inorganic forms.

Environmental Microbiology

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Biogeochemical Cycling

Biological and chemical processes involved in the cycling
and transformation of nutrients.


Microorganisms play an essential role in transformation of




Environmental Microbiology

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Biogeochemical Cycling

Biological and chemical processes involved in the cycling
and transformation of nutrients.


Microorganisms play an essential role in transformation of



-

Carbon



-

Nitrogen



-

Sulfur



-

Iron



-

Manganese



-

Phosphorous

Environmental Microbiology

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Carbon Cycle

Environmental Microbiology

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Carbon Cycle

-

carbon is the major chemical element of most organic matter.

-

recycled and reused through the biosphere and all of its
organisms.

-

microorganisms: respiration (CO
2
).

Environmental Microbiology

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Nitrogen Cycle

1.
Fixation






2. Nitrification




3.
Denitrification




4. Decay

1.

4.

2.

3.

Environmental Microbiology

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Nitrogen Cycle

1.
Fixation

Nitrogen in the atmosphere is converted
to ammonia.

(
Azotobacter
,
Rizobium
,
Clostridium
)



2. Nitrification

Oxidation of ammonia to nitrite
(
Nitrosomas
) and nitrate (
Nitrobacter
).


3.
Denitrification

Anaerobic respiration


release of N
2

(
Pseudomonas
denitrificans
)


4. Decay

Decomposers


release of
ammoina

from excretion and dead organisms

1.

4.

2.

3.

Environmental Microbiology

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Phosphorous Cycle

Environmental Microbiology

The largest reservoir of
phosphorus is in sedimentary rock.


When it rains, phosphates are
removed from the rocks and are
distributed throughout both soils
and water.


Plants take up the phosphate ions
from the soil moves from
plants to animals.


Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Phosphorous Cycle

Environmental Microbiology

The largest reservoir of
phosphorus is in sedimentary rock.


When it rains, phosphates are
removed from the rocks and are
distributed throughout both soils
and water.


Plants take up the phosphate ions
from the soil moves from
plants to animals.


Phosphates return to the soil through:



the excretion of urine and feces



the decomposition of plants and animals after death

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Sulfur Cycle

Environmental Microbiology

Weathering

of rocks releases
stored sulfur (contact with air
-

sulfate.


Sulfate is taken up by plants and
microorganisms and is converted
into organic forms
moves through the food chain.


Decomposition of plants and
animals release sulfate.

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Sulfur Cycle

Environmental Microbiology

Weathering

of rocks releases
stored sulfur (contact with air
-

sulfate.


Sulfate is taken up by plants and
microorganisms and is converted
into organic forms
moves through the food chain.


Decomposition of plants and
animals release sulfate.

Natural sources
-

volcanic eruptions, the breakdown of organic matter
in swamps and tidal flats, and the evaporation of water.


Come down within rainfall.

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Environmental Biotechnology

Environmental Biotechnology is the application of biotechnology for
solving environmental problems



Role of microorganisms in waste treatment


-

treatment of waste water (sewage) and industrial effluents,

landfills, composting



Biotechnological processes to protect the environment


-

bioremediation, environmental monitoring,
biofertilisers
,

biocontrol



Environmental benefits through agricultural biotechnology


-

biofuels, GM crops, transgenic and cloned animals


Environmental microbiology tries to understand microbial
ecosystems and environmental biotechnology tries to manipulate
them to protect the environment and create cleaner processes.

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Role of microorganisms in waste treatment

Microorganisms in Water Quality



Environmental Biotechnology

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Role of microorganisms in waste
treatment

Microorganisms in Water Quality



Use of microorganisms to treat wastewater.


activated sludge


secondary treatment.


raw sludge


anaerobic digestion.



Indicators of fecal contamination


Water


potential carrier of disease.


Monitoring and detection of indicator microorganisms.



Eutrophication

Environmental Biotechnology

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Wastewater Treatment



Production of waste from human activities is unavoidable. A
significant portion of this waste will end up as wastewater.




Sewage or wastewater is composed of:


-

Domestic used water and toilet wastes


-

Rainwater


-

Industrial effluent


-

Livestock wastes




99.9% water and 0.1% waste.




Wastewater treatment systems take human and industrial
liquid wastes and make them safe enough to return to the
aquatic environment.




Wastewater treatment systems use natural processes of
purification only they do it faster and in a controlled situation.

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Wastewater Treatment

Four categories of pollutants in wastewater

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Wastewater Treatment

Four categories of pollutants in wastewater

1. Debris and Grit.

2. Particulate Organic Matter.

3. Colloidal and dissolved organic material.

4. Dissolved inorganic material.

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Wastewater Treatment

Constituents in Wastewater

Constituent

Risk

Microorganisms (pathogenic
bacteria, virus etc.

Bathing and consumption of shellfish
and untreated or improperly

treated
water

Biodegradable organic material

Oxygen depletion resulting in fish
kills

and
odours

Other organic materials e.g.

detergents, pesticides, fat, oil

Toxic effect, bioaccumulation

Nutrients (nitrogen,

phosphorous)

Eutrophication

Metals

(Hg,
Pb
, Cd, Cr, Cu, Ni)

Toxic effect, bioaccumulation

Other inorganic

materials (acids e.g.
hydrogen sulfide)

Corrosion,

toxic effect

Thermal effects

Changing living

conditions

Odour

Aesthetic

inconvenience

Radioactivity

Toxic effect, bioaccumulation

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Wastewater Treatment

Wastewater is infectious

Microorganisms in wastewater come mainly from human and animal excreta

Example of infectious organisms


E. coli


C. perfringens


Fecal
Streptococcae


Salmonella


Shigella


Vibrio cholera


Camplyobacter


Coliphages


Protozoa (
Giardia
,
Cryptosporidium
)


Enterovirus


Rotavirus


Helminthes


Microorganisms transmitted by the fecal
-
oral route are usually referred to as
enteric pathogens because they infect the gastrointestinal tract.

Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Wastewater Treatment


Waterborne diseases are transmitted through ingestion of
contaminated water


passive carrier of infectious agent(s).


Pathogens are almost always present at some level in domestic
sewage.


-


-



The concentration of enteric pathogens varies


-



-



-



-


Lecture 7

ENVI7001 Environmental Science and Industrial Hygiene

Wastewater Treatment


Waterborne diseases are transmitted through ingestion of
contaminated water


passive carrier of infectious agent(s).


Pathogens are almost always present at some level in domestic
sewage.


-

infected individuals excrete large numbers of pathogen


-

people who are not ill can also excrete pathogens


The concentration of enteric pathogens varies


-

incidence of infection within a community


-

access to healthcare


-

time of year

Lecture 7