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Effect of Light and Oxygen on Freshwater Microbial Population |
Effect of Light and Oxygen on Freshwater Microbial Population
Freshwater
bodies are divided into tree zones based on oxygen availability and light
penetration :
a.Litoral
zone - light
penetrates through it and oxygen is available.
b.
Limnetic zone - open water away from the shore, has effective light
penetration and oxygen is available.
c.
Profundal zone - Deeper water has low oxygen and less light.
Litoral
zone
Litoral zone is submerged with higher plants.
Limnetic
zone
Limnetic zone contains pseudomonads and species of Caulobacter, Cytophaga and Hyphomicrobium.
Photosynthetic algae are located inthis zone. Light is an
important source of energy for them. They are primary producers of a lake and
supports a population of bacteria, protozoa and other aquatic lives.
Profundal
zone
Purple and green sulfur bacteria are found in this zone.
They are anaerobic photosynthetic organisms that metabolize hydrogen sulfide to
sulfur and sulfate in the bottom sediments of the benthic zone.
Algal growth near the surface often filters the light and
use different wavelength of light from those used by the surface layer
photosynthesizers.
The sediment in the benthic zone includes bacteria such
as Desulfovibrio that use sulfate as
an electron acceptor and reduce it to hydrogen sulfide. Methane producing
bacteria are also part of these anaerobic populations.
Clostridium species
are common in benthic zone and cause botulism in water flow.
Effect of
Light and Oxygen on Freshwater Microbial Population
Written By
Sadia Akhtar
Student of Department of Microbiology
Jagannath University.
Email- sadiabd810@yahoo.com
Student of Department of Microbiology
Jagannath University.
Email- sadiabd810@yahoo.com
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