ABSTRACT
This study was carried out to isolate some of the possible species of microorganisms on different constructional and decoration materials of buildings. A total of 42 microbial isolates was isolated from constructional and decoration materials of building materials samples. 31 were bacterial strains and 11 fungal species. The details of these isolates comprising Bacillus species (3), Staphylococcus aureus (8), Escherichia coli (9), Proteus species (5), Pseudomonas species (6), Aspergillus Niger (3), Aspergillus flavus (4) and Mucor Alternaria (4). From the findings in this study, it was observed that Escherichia coli is the most frequently occurring isolate from decoration materials of buildings with the highest percentage occurrence of (21.1%), followed by Staphylococcus aureus and Proteus sp (15.8%), then Pseudomonas sp, Bacillus sp, Aspergillus flavus, Mucor Altenaria (10.5%) and Aspergillus niger (5.3%), whereas it was observed that Escherichia coli and Staphylococcus aureus is the most frequently occurring isolate from constructional materials of buildings with the highest percentage occurrence of (21.7%), followed by Pseudomonas sp (17.4%), then Proteus sp, Aspergillus flavus, Mucor Altenaria, Aspergillus niger (8.7%) and Bacillus sp (4.3%). The high occurrence of Escherichia coli and Staphylococcus aureus is a major component of the normal flora of the constructional and decoration materials of buildings, which probably explains its high ability to deteriorate constructional and decoration materials. The total viable microbial counts of constructional and decoration materials of building samples ranges from 1.2x106 cfu/g to 3.7 x106 cfu/g. All the deteriorations were associated with one or more different species of fungi. Also most of the deteriorations caused by bacteria were found to be by more than one type of bacteria. Statistical analysis showed that there were significant differences in mean count of the locally made cream samples at P< 0.05.
TABLE OF CONTENTS
Title
Page i
Certification ii
Dedication iii
Acknowledgement iv
Table
of Contents v
List
of Tables vii
Abstract viii
1.0 CHAPTER ONE
1.1 Introduction 1
1.2 Causes of Microbial Contamination 5
1.2.1 Disasters 5
1.2.2 Poor Environmental Control 6
1.2.3 Normal Conditions 8
1.3 Aims and Objectives 8
1.3.1 Objectives 9
2.0 CHAPTER TWO
2.1 Literature Review 10
2.1 Microorganisms
Associated With Deteriorated De-Surface Painted
Concrete
Buildings 11
2.2 Microbial Deterioration of Constructional
Materials 12
2.3 Moulds In Buildings 13
2.4 Biodeterioration of Historic Buildings 14
2.5 Moisture and Limiting Factor Water
Activity 17
2.6 Damage Due To Microorganisms 17
2.7 Characterization
of New Bacterial Species 18
3.0 CHAPTER THREE
3.1 Materials and Method 20
3.2 Study Area 20
3.3 Collection of Samples 20
3.4 Sterilization of Materials 21
3.5 Preparation of Culture Media 21
3.6 Preparation of Dilution Factor/Swab
method 21
3.7 Inoculation and Isolation 21
3.8 Purification
of Isolates 22
3.9 Identification of Bacterial Isolates 22
3.9.1 Gram
Staining 22
3.9.2 Biochemical Test 23
3.9.2.1 Indole Test 23
3.9.2.2 Methyl Red (MR) 23
3.9.2.3 Voges Proskauer (VP) 23
3.9.2.4 Hydrogen Sulphide Test (H2S) 23
3.9.2.5 Citrate Test 24
3.9.2.6 Urease Test 24
3.9.2.7 Catalase Test 24
3.9.2.8 Coagulase Test 24
3.9.2.9 Sugar Fermentation Test 25
3.9.2.10Starch
Test 25
3.10 Identification of Fungal Isolates 25
3.11 Statistical Analysis 26
4.0 CHAPTER
FOUR
4.1 Results 27
5.0 CHAPTER
FIVE
5.1 Discussion, Conclusion and Recommendation 35
5.1.2 Conclusion 37
5.1.3 Recommendation 37
References 38
LIST
OF TABLES
|
TABLE
|
TITLE
|
PAGE NO
|
|
1
|
The effects of microbial activities on historic buildings
|
16
|
|
2
|
Total viable
microbial count of constructional and decoration materials of building samples
|
29
|
|
3
|
Morphological Identification of
Bacterial Isolates From constructional and decoration materials of building
sample
|
30
|
|
4
|
Biochemical
Identification, Gram Reaction and Sugar Utilization Profile of bacteria
isolates.
|
31
|
|
5
|
Cultural Morphology and
Microscopic Characteristics Fungal Isolates from Constructional and
Decoration Samples.
|
32
|
|
6
|
Percentage occurrence of isolates from decoration
materials of building material samples
|
33
|
|
7
|
Percentage occurrence of isolates from
constructional materials of building material samples.
|
34
|
1.0 CHAPTER
ONE
1.1 INTRODUCTION
Construction
material is
any item used in construction projects that is
added to the structure or building. Building
materials are used for construction purposes. Many naturally occurring
substances, such as clay, rocks, sand and wood have been used to construct
buildings. Apart from naturally occurring materials, many man-made products are
in use, some more and some less synthetic (Andersen et al., 2011). The manufacturing of building materials is an
established industry in many countries and the use of these materials is
typically segmented into specific specialty trades, such as carpentry,
insulation, plumbing, and roofing work. They provide the make-up of habitats
and structures including homes.
Decoration
materials are the materials and items used to
improve the service and decorative qualities of buildings and structures, as
well as to protect structural members from atmospheric and other effects (Roberts
et al., 2000). The main decoration
materials in modern construction include finishing mortars and concretes;
natural and artificial masonry materials; decorative ceramics; materials and
items made from paper, glass, plastic, and metals; and paints and varnishes. Decoration or
finishing materials are usually designed for interior or exterior finishing;
some materials are used for both (for example, natural decorative stone,
ceramic materials, and architectural glass). A special group consists of
materials and items for covering floors, which must meet a number of specific
requirements (negligible wear, high impact strength, and so on). Decoration
materials also include acoustic materials, which are used simultaneously as
sound-absorbing coatings and as a decorative finish for the interiors of
theaters, concert halls, and motion-picture theaters (Ortega-Morales et al., 2000). An arbitrary distinction is made between finishing materials
proper, which are used mainly to form decorative and protective coatings
(varnishes and paints)
Newly
built, re-constructed and many times repaired blocks of flats get damp and
start to mold due to different reasons. Walls and ceilings of newly built or
recently repaired flats become damp as a consequence of various overflows
(Roberts et al., 2000). In one such
flat an increased contamination with micromycete propagules formed as a result
of flooding; the ceiling got damp and micromycetes started developing, their
spores started to spread in the environment. The patches formed on the ceiling
and they were increasing in size. A small break of a pipe and water
leakage
was revealed one floor higher. Under conditions of sufficient humidity
micromycetes form colonies and conidiophores, conidia and other organs, spread
in the environment as propagules and gradually with dust settle of various
objects. With airflow they enter all the premises, contaminate the air, settle
on various objects and get into food. Some allergic people are sensitive to
this contamination (Videla and Herrerii, 2005). Fungi recorded in these
premises are not evident pathogens, but they could not be considered safe
either, especially those of the Aspergillus, Penicillium, Cladosporium
genera because these sources name them as possible agents of respiratory
and other diseases (Vincke et al.,
2001). Occupants of newly built blocks of flats sometimes realize the presence
of excess humidity and mold odor as well as coating and stains on walls and
ceilings after they have moved in. In the air of such flats low amount of
micromycete propagules is determined. Bacteria and yeasts comprise the majority
of the recorded microorganisms (Shinkafi and Haruna, 2013). Concrete is one of
the strongest construction materials applied in centuries all over the world.
However, they can get destroyed for a variety of reasons including the material
limitations, poor quality design and construction practices, as well as the
hard exposure conditions. Desurface painted concrete is the removal of paint
from the surface of concrete due to the environmental factors or activities of
microorganisms (Ortega-Morales et al.,
2000). Many architectural and other buildings structures undergo
biodeterioration when exposed to contact with soil, water, sewage, as well as
food, agricultural products and waste materials. Biodeterioration refers to
undesirable changes in a material, caused by living organisms (Hyvärinen et al., 2002). Living organisms form
specific communities that interact in many different ways with mineral
materials and their external environment. This complex phenomenon occurs in
conjunction with many physical and chemical destructive processes. Thus, it is
difficult to distinguish an extent of the damage caused by biotic factors from
that resulting from abiotic ones. However, according to United States
estimation, the contribution of microorganisms to the deterioration of materials
as a whole may be within the range of 30% of deterioration (Tomaselli et al., 2000). Biologically influenced
corrosion of concrete has most often been detected in building foundations and
walls, and also in constructions such as dams, harbour and maritime structures,
bridges, tanks, pipelines, cooling towers, silos and many others (Zanardini et al., 2000). This type of concrete
deterioration occurs often in the food processing and storage works and in the
abattoirs and buildings of holdings, in which the different microorganisms
including bacteria, fungi, and algae are usually present at increased
concentration. They colonize the material surface, and its pores, capillaries
and micro-cracks, and cause the concrete damage resulting in aesthetic, functional
or structural problems (Roberts et al., 2000). Concrete buildings
though having a hard texture are still subject to the very slow but inevitable
process of corrosion and microbial deterioration. These buildings can not
resist deterioration for a long time because some of their components are
utilizable by microorganisms. The concrete building is made up of stone, cement
and paint. The paint on its own is compose of pigment, binder or medium,
thinner and drier some of which are attacked by microorganisms (Videla and
Herrerii, 2005). Stone is subjected to both physical and chemical deterioration
but yet how microorganisms contribute to this deterioration is not very clear
(Bock and Sand, 2001). Agents of concrete building deterioration include both
microbial and non-microbial. The non microbial include temperature, moisture
and acid rain. The microbial agents on the other hand are the fungi and
bacteria. It has being known for many years that mass of microorganisms are
present in the eroded masonry monuments (Vincke et al., 2001). Marble and calcerous blocks are sensitive to
environmental impacts. Fungi have an upper hand than bacteria in concrete
building spoilage and lichens are responsible for local marble disintegration. Videla
and Herrerii, (2005) isolated bacteria from ancient monuments in South Britain
showing that some unidentified strains were able to solubilize calcium from
stone (Shinkafi and Haruna, 2013). The types of microorganisms associated with
concrete building deterioration include fungi like Aspergillus, Penicillium,
Alternaria, Cladosporium and others. The bacteria are the member of
the Cyanobacteria, nitrifying bacteria and Thiobacilli (Ortega-Morales
et al., 2000). The mechanism
of deterioration by microorganisms is through utilization of the
organic and inorganic building components for energy generation. In
painted surfaces, the paint which also contain nutrients such as latex,
cellulose and the organic solvent used are attacked first before the
microorganisms get access to the concrete, various forms of acid
organic and inorganic are produced by the microorganisms which cause the
solubilization of the concrete block (Tomaselli et al., 2000). The ammonia oxidizing bacteria oxidizes the
ammonia to nitrate. The bacilli generate energy from the oxidation of reduced
sulphur compounds producing sulphuric acid as the end product. In Nigeria,
buildings are subjected to various forms of deterioration, but little or no
effort has been made to study the microbial biodeterioration of the buildings
(Zanardini et al., 2000).
1.2 CAUSES
OF MICROBIAL CONTAMINATION
The
presence of excessive microbial growth in a building is the result of any one
or combination of three separate causes: Disasters, Poor Environmental Control and Normal Conditions. In
reality, all microbial contamination in buildings is ultimately derived from
microbes brought in from outside. There is no such thing as spontaneous
generation. However, many building materials such as drywall and other
manufactured products come “pre-innoculated” with viable spores, meaning that
microbial growth can be initiated immediately upon the addition of moisture
(Pietarinen et al., 2008).
1.2.1 Disasters
Disaster
conditions can result in uncontrolled microbial growth. Frequently, the types
of species that dominate such environments include both highly toxigenic and
pathogenic varieties - Stachybotrys chartarum, for example, commonly
grows on wet drywall paper following flood conditions. All receptive surfaces
in the building that are subject to direct wetting will become colonised if
they remain wet for long enough and, after a short time, other surfaces in the
building that have been exposed to the humid conditions that follow the
disaster will also be colonised, normally by an at least partially different
group of organisms (Pośniak et al., 2005). Some of these are
as equally unacceptable in indoor environments as those that grow in the areas
of direct wetting. Immediate control of the disaster conditions is required to
prevent microbial destruction of the environment. Restoration firms are well aware
that drying must be implemented within 48 hours and be complete within 96 hours
or else major restoration, done under carefully controlled conditions, will be
necessary. Disaster restoration is a thankless, disruptive, dirty and expensive
business. It is like wrestling with a pig where everyone gets dirty but only
the pig likes it. Typically, disaster restoration involves removal and
replacement of flooring, wall coverings and most furnishings. Workers and
surrounding uncontaminated areas must be protected from exposure to spores,
body parts and chemical metabolites of the many types of fungi and bacteria
that thrive in such conditions (Roberts et
al., 2000). Given the ability of water to penetrate into all available
areas, microbial contamination is often discovered after the restoration was
thought to be complete. This creates the ideal environment for litigation, a
compelling reason to prevent microbial contamination if at all possible. In the
past, insurance firms typically provided insurance coverage for disaster
restoration, including the cost of cleaning up mould growth. However, on the
down side, the firms doing the cleanup seldom had any education in doing this,
often consisting of little more than general untrained laborers with a few
skilled trades persons (Shinkafi and Haruna, 2013). More recently, insurance
firms require restoration contractors to have significant training in microbial
remediation but, unfortunately, they now generally explicitly exclude all forms
of mould growth from coverage. In fact, they cover only the water loss
component of disasters. Mould growth that results from water loss is not
covered, mostly due to the seemingly simple fact that microbial growth can be
prevented if water is cleaned up quickly. Generally, this is academically
correct although it often happens differently in the real world of “Murphy’s Law”.
This clearly puts an onus on the building owner to implement programs such that
microbial growth is minimised. However, building science has not generally
changed the construction methods appreciably to provide much help. If it gets
wet, it will generally support growth (Shirakawa et al., 2002).
1.2.2 Poor Environmental Control
Microbial
growth does not require flooding or even direct wetting of surfaces to
initiate. Simply allowing the relative humidity to remain above 65% for
extended periods of time will initiate growth (Tomaselli et al., 2000). Every basement in every house that smells like dirty
socks when you walk down the stairs is evidence of this. Common situations that
permit mould growth include:
•
Lack of meaningful dehumidification in below grade environments
•
Carpeting laid directly on concrete slabs-on-ground (on- and below-grade)
•
Construction during humid summer conditions without sufficient ventilation
•
Installation of drywall before buildings is water-tight
•
Inadequate drying and control of relative humidity in non-water damaged areas
of buildings following flooding
Many
building materials, including drywall and fabricated wood products, are very
hydrophilic and will readily absorb water from the air when the relative
humidity is suitably high. In most buildings with insufficient ventilation, the
highest humidity will be near the floor and cold exterior walls. These
conditions are exacerbated by storage of materials and placement of furniture
near these walls, which reduces air flow and allows even cooler conditions and
higher humidity to develop.
Unfortunately,
basements are often used for storage, have limited ventilation, are prone to
leakage and are seldom dehumidified. This is a receipe for mould growth,
especially in residential environments. The choice of building materials is
also a factor. The increased use of manufactured wood products and use of
paper-surfaced drywall creates environments perfect to support mould growth.
Remember that even the stupidest of the three little pigs didn’t build his
house out of paper! Efforts to control heat loss by reducing the amount of
fresh air further compound the problem (Videla and Herrerii, 2005). Remediation
of these conditions, like disaster restoration, generally involves disruptive
practices and substrate removal, all under conditions to contain dust and
protect workers.
1.2.3 Normal Conditions
Certain
conditions in buildings are normally conducive to microbial growth. Some of
these environments include:
•
Garbage storage areas and composting containers
•
Foyers and other entranceways that receive foot traffic
•
Spas, showers, locker rooms and pools where moisture is simply inevitable
•
Bathrooms, especially in hospitality buildings
•
Interior surfaces of air conditioners
•
Processing machinery that uses water
•
Evisceration plants and similar areas where daily washdowns are required
•
Greenhouses
•
Compositing and recycling facilities.
In
these areas, dealing with water may be essentially impossible. At the very
best, extreme diligence is required to remove excess water immediately. Yeast
like organisms thrive in such environments. In composting facilities, risk
control is essentially an exercise in worker protection, as the elevated
temperatures and continuous supply of organic matter permits unrestricted (and
intended) microbial growth (Vincke et
al., 2001).
1.3 AIMS AND OBJECTIVES
This
study is therefore, aimed at isolation of some of the possible species of
microorganisms on different constructional
and decoration materials of buildings.
1.3.1 Objectives
·
To isolate and characterize
microorganisms present on constructional materials of buildings
·
To isolate and characterize
microorganisms present on decoration materials of buildings
·
To determine the
percentage occurrence of the isolates.
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