MICROBIAL FLORA OF AQUATIC ENVIRONMENTS,

PRESENTED BY;

Prof. F. Tahir

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.

TYPES OF AQUATIC ENVIRONMENTThe 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.

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.

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

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.

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.

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:

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.)

Extremophilous Bacteria (edapted from the University of luscfa)

Microbial factorsMicrobial 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.

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