The Role of Useful Microorganisms in the Ecosystem

7/28/2019 The Role of Useful Microorganisms in the Ecosystem

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The role of useful

microorganisms in the ecosystem


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1) Nitrogen fixing bacteria

Plants cant absorb atm nitrogen directly

Can only use N in the form of

Ammonium

Nitrite

Nitrate

Nitrogen-fixing bacteria assimilate atm N into

ammonium compound(NH3 / NH4+) Nostoc sp.

Rhizobium sp.


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Nitrates plant protein

Animal eat plant : organic N animal protein

Waste matter/dead plants & animals

ammonium compounds

Ammonia nitrites (NO2-) nitrates(NO3-)

Nitrosomonas sp. Nitrobactersp.

OXIDATION (adding oxygen)


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Nitrogen is returned to the atm by denitrifying

bacteria through denitrification

Nitrates gaseous nitrogen + oxygen

Returned to atm

Used by bactBy bacteria


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Nitrogen cycle


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2) Saprophytic bacteria

Saprophytic bacteria and fungi return the

nutrients to the atm, soil and water

Without them, the nutrients stored in the

dead bodies cannot be used to enrich the soil,

soil would become less fertile and can no

longer sustain plant life and the community on

the whole.


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3) Mutualistic protozoa

Termites cannot produce enzyme cellulase to

digest cellulose (in wood)

Trichonympha sp. are present in the

alimentary canal of the termites.

They secretes cellulase which help to digest

the cellulose


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4) Symbiotic bacteria

Found in the human colon

They synthesise vitamin B12 and K


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Methods in the

transmission ofdiseases

VECTORS

-cockroaches, mosquitoes, flies-

carriers

-malaria caused by Plasmodiumcarried by Anopheles sp.

AIRBORNE & DROPLET

TRANSMISSION

- Respiratory system- Cough, sneeze (colds)

- -spores of pathogens

(tuberculosis)

DIRECT CONTACT

- Skin: towels, bedlinens

clothing of infected

person

- Sexual intercourse

FOOD AND WATER

-contaminated w mo

-faeces of infected

-Unwashed hand(typhoid n cholera)


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Methods of controlling

pathogens

ANTIBIOTICS

- Pennicillin & streptomycin

- Chemical subs produced by mo- Used to kill other mo

VACCINES

-Modified or weakened viruses or

suspensions of dead bacteria

- Inoculated into the body to induce theproduction

DISINFECTANTS

- Solution used to kill mo on the

surfaces- Sterilise surgical equipments

- Phenol, formmaldehyde, carbolic acid

ANTICEPTICS

- Applied on cuts to kill/inhibit the

growth of mo

- Acriflavin n iodine


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The use of MO in biotechnology

Production of antibiotics, vaccines, hormones

Production of energy from biomass

Cleaning of oil spills Waste treatment

Production of biodegradable plastic

Food processing


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WHAT IS THE IMPORTANCE OFPRESERVATION AND

CONSERVATION OF BIODIVERSITY??

The Role of Useful Microorganisms in the Ecosystem

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