ABSTRACT
Nutrient agars and potato Dextrose agar
were prepared and poured into petridishes and exposed to the air of
microbiology laboratory of Osun State Iree, for 10mins. Bacteria and fungi were
isolated and identified. The isolated bacteria were Beallus cereus, Staphylococcus
aureus and Pseudomonas aeruginosa. While the fungi
isolated were Aspergillus niger and Saccharomyces cerevisiae.
TABLE OF CONTENT
TITLE PAGE I
CERTIFICATION II
APPROVAL PAGE III
DEDICATION IV
ACKNOWLEDGMENT V
TABLE OF CONTENT VI
ABSTRACT VII
CHAPTER
ONE
1.0 INTRODUCTION 1
– 2
CHAPTER TWO
2.0 LITERATURE
REVIEW 3
– 7
2.1 PURPOSE OF
STUDY 7
CHAPTER THREE
3.0 MATERIALS
AND METHODS 8
3.1 MATERIALS
USED 8
3.2 STERILIZATION
OF SAMPLES 8
3.3 COLLECTION
OF SAMPLES 8
3.4 PREPARATION
OF MEDIA 8
3.5 INOCULATION
OF MEDIA 9
3.6 SUB-CULTURING
OF MICROBIAL GROWTH 9
3.7 MAINTENANCE
OF PURE CULTURE 9
3.8 CHARACTERIZATION
OF FUNGAL ISOLATES 9
3.9. CHARACTERIZATION
OF BACTERIAL ISOLATES 9
– 10
3.9.0 GRAM
STAINING 10
3.9.1 SPORE
STAINING 10
3.9.2 COAGULASE
TEST 10
3.9.3 CATALASE
TEST 10
– 11
3.9.4 MOTILITY
TEST 11
3.9.5 IDENTIFICATION
OF BACTERIAL ISOLATES 11
CHAPTER FOUR
4.0 RESULTS
AND DISCUSSION 12
– 14
CHAPTER FIVE
5.0 CONCLUSION
AND RECOMMENDATION 15
– 16
REFERENCES 17
CHAPTER ONE
1.0 INTRODUCTION
Gases, dust particles, water vapour and
air contain microorganisms. There are vegetable cells and spores of bacteria,
fungi and algae, viruses and protozoa cysts. Since air is often exposed to
sunlight, it has a higher temperature and less moisture. So, if not protected
from desiccation. Most of these microbial forms will die. Air serves as
transport or dispersal medium for microorganism they occur in relatively small
number in air when compared with soil or water. The microflora of air can be
studied under two headings outdoor and indoor microflora.
Outdoor Microflora: - The air in the atmosphere, which is
found outside the buildings, is referred to as outside air. The dominant
microflora of outside air are fungi. The two common genera of fungi are cladosporiul and sporobolomyces, besides this two general, under general found in
air are Aspergillus, Alternaria, Phytophthora and Erysiphe.
The outdoor air also contains besidispores,
ascopres of yeast, fragments of mycelium
and canidia of molds. Among the
bacterial genera Bacillus and clostridium, sarcina, mirococcus, corynebacterium and Achromobacter are widely found in the outside air, the number and
kind of microorganism may very from place to place, depending upon the human
population densities.
Indoor Microflora: - The air found inside the building is
referred to as indoor air. The commonest genera of fungi in indoor air are penicillium, Aspergillus, the Commonest
genera of bacteria found in indoor air are Staphylococci,
Bacillus and Clostridium. In case of occupants being infected, the composition
shows slight variations with latitude and to a lesser extent with attitude. The
ozone owes its existence in the atmosphere to photosynthesis from oxygen under
the influence of solar ultraviolet radiations. (Dr. Shiva, 2009).
There is no microbes are native to the
atmosphere rather they represent allochthonous populations transperted from aquatic
and terrestrial habits into the atmosphere. Microbe of air within 300 – 1,000
or more feet of the Earth’s surface are the organisms of soil that have become
attached to fragments of dried leaves, strain or dust particles, being blown
away by the wind. Species vary greatly in their sensitivity to a given value of
relative humidity, temperature and radiation exposure.
More microbes are found in air over land
masses than far at sea. Spores of fungi especially Alterneria, Cladosporium, Penicillium and Aspergillus are more numberous than other forms over sea within
about 400 miles of land in both polar and tropical air masses at all altitudes
up to about 10,000 feet.
Microbes found in air over populated
land areas below altitude of 500 feet in clear weather include spores of Becillus and Clostridium ascos-pores of yeasts, fragments of mycelium and spores of molds and streptomycetaceae, pollen pootozoan cysts, algae, micrococcus, corynebacterium etc.
In the dust and air of schools and
hospital wards or the rooms of persons suffering from infectious disease,
microbe such as tubercle bacilli, streptococci, pneumococci
and staphylocci have been
demonstrated. These respiratory bacteria are dispersed in air in the droplets
of saliva and mucus produced by coughing, sneezing, talking and laughing.
Viruses of respiratory tract and some
enteric are also transmitted from the objects contaminated with infectious
secretions that after drying become infectiou dust. Droplet are usually formed
by sneezing, coughing and talking. Each droplet consists of saliva and mucus
and each may contain thousands of microbes. It has been estimated that the
number of bacteria in a single sneeze may be between 10,000 and 100,000. Small
droplets in a warm dry atmosphere are dry before they reach the floor and thus
quickly become droplet nuclei.
Many plant pathogens are also
transported from one field to another through air and the spread of many fungal
diseases of plants can be predicted by measuring the concentration of airborne fungal
spores. Human bacterial pathogen which cause important airborne disease such as
diphtheria, meningitis, pneumonia, tuberculosis, and whcoping cough are
described in the chapter “Bacterial Disease man”
Air does not have an indigenous and
flora, though a number of micro-organism are present in the air. Air is not a
natural environment for microorganisms as it doesn’t contain enough moisture
and nutrients to support their growth and reproduction. Quite a number of
sources have been studied in this connection and almost all of them have been
found to be responsible for the air microflora. One of the most common sources
of air microflora is the soil. Soil microorganisms when distributed by the wind
blow librated into the air and remain suspended therefore along period of time.
Man made actions like digging or ploughing the soil may be release soil born
microbes into the air. Similarly microorganisms found in water may also be
released into the air in the form of water droplets or aerosols, splashing of water
by wind action a tidal action may also produce droplets or aerosols?