1. MICROBIAL FLORA OF AQUATIC
ENVIRONMENTS,
PRESENTED BY;
Prof. F. Tahir

2. INTRODUCTION
• Microflora are microbes normally associated with certain tissues, organs or
particular environment.
• Aquatic environment is an ecosystem in the body of water.
• It consist of all the microbes such as protozoans, viruses, Bacteria, fungi and
algae etc. that inhabit the water.
• Aquatic microbes are broadly divided into 3 communities. The planktons,
Haptobenthos and Herpobenthos.

3. TYPES OF AQUATIC
ENVIRONMENT
The main types of aquatic environment are :-
 Marine water
 Fresh water
Marine environment: these covers approximately 70% of the
earth surface, and contains 97% of planet water. The generate
32% of the worlds net primary production. Marine ecosystems
can be divided into many zones depending on the water depth
and shore line.

4. Fresh water: these covers 0.80% of the earths surface and
inhibits 0.009 of its total water. The generate nearly 3% of its
net primary production. Fresh water ecosystem contain 41%
of the world known fish species.
there are three basic types namely:-
 Lentic: these are slow moving water e.g ponds, pools and
lakes.
 lotic: these are fast moving water e.g streams and rivers.
 Wetland: these are areas were the soil is saturated for at least
some time.

5. TYPES OF MICROORGANISMS FOUND
IN AQUATIC ENVIRONMENT
There are two main types of microorganisms found in an aquatic
environment these are:-
 Planktons: these is the aggregation of floating and drafting
microbial life in surface region of an ecosystem. Plankton may
be composed primarily of algae (phytoplanktons), protozoa
and other minute animals (zooplanktons).the most important
planktons are the phototrophic organisms.
 Benthic microorganisms: these are microorganisms that
inhabit the bottom region of the body of water. The benthic
zone is the most richest region of an estuarine-marine system
in terms of numbers and kinds of organisms beginning from
high tides extending to the depth below

6. SOURCES OF MICROORGANISMS IN
AQUATIC ENV.
Microorganisms are responsible for contamination of water
bodies causing diseases. Therefore the sources are:
i. Air- Presence of heavy storm carries micobes from the
soil and drains them into the water bodies.
ii. Soil : As a result of tidal waves ,animal manure and
plant residues when washed into water bodies increase
algal blooms and microorganism population.
iii. Human activities: Improperly sited or maintained septic
systems may discharge human wastes into underlying
groundwater, domestic sewages could be deposited
directly or indirectly.

7. SOURCES OF MICROORGANISMS IN
AQUATIC ENV. Cont.
Animals like cattle, birds and domesticated animals
can void faces directly into water bodies during
their movement and consuming water with their
mouth could contaminate water bodies.
iv. Agricultural sources: Manure applied on farms can
contribute microorganisms to aquatic environment
via run off and erosion, microorganisms are been
washed or seep into ground water from
agricultural field during farming practices.
v. Indusrial discharge/effluent.

8. Adaptation of micro Orgamisms to
aquatic Habitats
An adaptation is a physical characteristic or behavior of a
species that increases that species' chances of survival in a
particular environment.
All living things are adapted to live in particular
environments. As changes occur within their environment,
those organisms that can adapt to the changes have a better
chance of surviving than those organisms that cannot adapt
to the changes.
The adaptive features developed by microorganisms(bacteria) to survive in
the aquatic habitat depends on:

9. Enviromental factors in the Aquatic
Habitats
There are five factors that have led to the development of adaptations by aquatic
species;
 Temperature e.g psychrophiles & mesophiles, (10 and 150C to 250C)
 Salinity (extreme environment) e.g halophiles(salt conc. of 10% ) e.g
Haloquadratum walsbyi & Haloarcula quadra
 Pressure (extreme environment) e.g barophiles
 Light
 Water movement (water current)
 pH
 Aeration(Oxygen content)
 Water depth (the largest number of organisms found in the superficial zone, where
many groups of bacteria and the number is decreasing to the great depths, but increased
again in the sediment where we found up to 420 million bacteria per gram of mud from
the sea.)

10. Extremophilous Bacteria (edapted from the
University of luscfa)

11. Microbial factors
Microbial adaptive features different aquatic habitats;
Capsule
Plasmid (extra chromosomal substance), which aid;
metabolism of hydrocarbons & various sugar(CH2O)
resistance to antibiotics, metal ions, u.v irradiation, bacteriophages &
ethidium bromide.
Flagellar (monotrichous, amphitrichous, liphotrichous &
peritrichous)
Encystment, in Ameoba spp. and some species of Bacteria.

12. Thank you for
Listening