CHARACTERIZATION AND ISOLATION OF INDIGENOUS MICROBES FROM WASTE DUMP SITE IN UMUAHIA METROPOLIS

ABSTRACT

This study evaluated the isolation and characterization of indigenous microorganisms from waste dump sites in Umuahia metropolis. A total of Ten (10) waste samples were collected from five (5) different dumpsites (designated as Ahieke, Ndioru, Umudike, Amoaba and Amawom wastes dump sites) which was located within Umuahia metropolis, two (2) samples each from the various locations were collected. The major bacterial species isolated include: Staphylococcus aureus, Escherichia coli, Streptococcus species, Klebsiella species and Bacillus cereus while the fungal species are Aspergillus niger, Aspergillus flavus, and Fusarium species respectively. The heterotrophic counts recorded in this study was found to be higher in Samples 3 (1.93 x105cfu/g) followed by Samples 4 (1.83 x105cfu/g) while the least bacterial count was recorded for Samples 8 (1.02 x105cfu/g). From the findings in this study, it was observed that Staphylococcus aureus and E. coli are the most frequently occurred isolates with a percentage occurrence of 9(31.0%) and 8(27.5%) respectively, while Aspergillus flavus 5(45.4%), was recorded as being the most predominant and frequently occurred fungi isolates. It can be concluded that the open dump system of waste disposal is indeed a potential environmental quality problem which takes the form of unsightliness, land and water pollution, it reduces the quality of air by the emission of foul odours and different gases derived from the anaerobic decomposition as well as occasional burning. Therefore, a land fill waste disposal system should replace the open system of waste disposal as this will ensure the effective control and prevention of microorganisms from escaping into the air.

TABLE OF CONTENTS

Title Page                                                                                                                                i

Certification                                                                                                                           iii

Dedication                                                                                                                              iv

Acknowledgements                                                                                                                v

Table of Contents                                                                                                                   vi

List of Tables                                                                                                                          viii

List of Figures                                                                                                                         ix

Abstract                                                                                                                                  x

CHAPTER ONE

1.0       Introduction                                                                                                                1

1.1       Aim of Study                                                                                                              4

CHAPTER TWO

2.0       Literature Review                                                                                                       6

2.1       Municipal Solid Waste                                                                                               6

2.2       Municipal Solid Waste Management                                                                         7

2.3       Reduce, Reuse and Recycle of Solid Wastes                                                             8

2.3.1    Waste Reduction and Reuse                                                                                       8

2.3.2    Recycling                                                                                                                    9

2.4       Treatment and Disposal of Solid Wastes                                                                   9

2.4.1    Thermal Treatment                                                                                                     10

2.4.2    Biological Waste Treatment                                                                                       12

2.5       Health Hazard Associated with Solid Waste Dump Sites                                          13

2.5.1    Occupational Health Hazards                                                                                     13

2.5.2    Hazards to the General Public                                                                                                13

2.6       Constrains Associated with Waste Management                                                       14

2.7       Waste Minimization                                                                                                   14

2.8       Effects of Solid Waste                                                                                                15

2.8.1    Air Pollution                                                                                                               15

2.8.2    Radioactive Emissions                                                                                               16

2.8.3    Water Pollution                                                                                                          16

2.8.4    Radioactive Effluent                                                                                                   16

2.8.5    Land Pollution                                                                                                            16

2.9       Microorganisms in Waste Dump Sites                                                                       17

2.10     Bacteria Species Associated with Solid Waste                                                          18

CHAPTER THREE

3.0       Materials and Methods                                                                                               20

3.1       Sample Collection                                                                                                      20

3.3       Media Used                                                                                                                 20

3.3.1    Preparation of Culture Media                                                                                     20

3.3.2    Sterilization Method                                                                                                   21

3.4       Sample Preparation and Isolation of Microorganisms                                               21

3.4.1    Sample Inoculation                                                                                                     21

3.4.2    Quantitative Estimation of Bacteria and Fungi Isolates                                             22

3.4.3    Purification of Isolates                                                                                               22

3.4.4    Colonial Morphology of the Bacterial Isolates                                                          23

3.5       Microbial Characterization and Identification                                                           23

3.5.1    Gram Staining Techniques                                                                                         23

3.6       Biochemical Tests                                                                                                      23

3.6.1    Indole Test                                                                                                                  23

3.6.2    Carbohydrate Utilization Analysis                                                                             24

3.6.3    Catalase Test                                                                                                               24

3.6.4    Coagulase Test                                                                                                           24

3.6.5    Citrate Utilization Test                                                                                               24

3.6.6    Motility Test                                                                                                               25

3.6.7    Voges-Proskauer Test                                                                                                 25

3.6.7    Oxidase Test                                                                                                               25

3.7       Identification of Fungal Isolates                                                                                 25

3.7.1    Wet Preparation                                                                                                          25

3.7.2    Colonial Morphology                                                                                                 26

3.8       Determination of Percentage Occurrence of Isolates from the Waste

            Dump Samples                                                                                                           26

CHAPTER FOUR

4.0       Results                                                                                                                        27

CHAPTER FIVE

5.0       Discussion, Conclusion and Recommendations                                                        41

5.1       Discussion                                                                                                                   41

5.2       Conclusion                                                                                                                  44

5.3       Recommendations                                                                                                      44

            References

LIST OF TABLES

LIST OF FIGURES

CHAPTER ONE

1.0       INTRODUCTION

            Waste (also referred to as rubbish, trash, refuse, garbage, or junk) can be described as unwanted or unusable materials (Khupe, 2006). Wastes may be generated during the extraction of raw materials, the processing of raw materials into intermediate and final products, the consumption of final products, and other human activities. Residuals recycled or reused at the place of generation are excluded. With population increase, there is increase in solid waste production making garbage pollution a serious problem (Khupe, 2006). Waste management in developing countries is usually equated with land disposal or discharge into water bodies (Cilinskis and Zaloksnis, 2006).

            This method of waste management is unscientific; a nuisance to the public, hence, the resultant effect is pollution. When waste is dumped on land, microorganisms such as bacteria and fungi proliferate using the components of the waste materials as source of nutrient for growth as well as degrading the organic materials in the waste. Umuahia city does not have a sanitary landfill (Moffat and Linder, 2006). As a matter of fact, waste materials are deposited in certain “open” dump sites in some areas in Umuahia and allowed to compile until they are taken away or incinerated. Improper disposal of untreated municipal solid waste is not only harmful to human health but also a threat to the environment (Ogbonna et al., 2006).

Pathogenic microorganisms and harmful chemicals in solid waste can be introduced into the environment when the waste is not properly managed (Ogbonna et al., 2006). Waste can contaminate surface water, ground water, soil and air which poses more problems for humans, other species, and ecosystems (Obire et al., 2002).

            In Nigeria as well as in most developing countries, the urban landscapes are littered with garbage, plastics, bottles, disposable cups, discarded tires and even human and live-stock faeces. These wastes are aesthetically unpleasant, constitute eyesores, produce unpleasant odour especially when their organic compositions are acted upon by putrefying bacteria. These refuse dumps thus constitute a habitat for vector and other nuisance organisms capable of transmitting or causing diseases such as typhoid, infantile diarrhoea and cholera in humans and animals (Onyido, et al., 2009). Refuse dumps refer to areas or land sites where material wastes from several sources and processes are deposited. Refuse dumps include both municipal solid wastes and industrial wastes including liquid effluents containing heavy metals (Olanrewaju, 2002). Refuse dumps provide a rich source of microorganisms most of which are pathogenic (Odeyemi et al., 2011).

            This is usually as a result of the attraction of rodents and vector insects for which the dump serves as shelter and food source (Donderski et al., 2000). Although it is known that vector insects and rodents can transmit various pathogenic agents of diseases such as amoebic and bacillary dysentery, typhoid fever, salmonellosis, cholera, plague and so on. A good percentage of these infections are caused by bacteria which are suspended in air around these refuse dumps which may later settle and cause contamination. Activities involving the disposal of solid wastes even if properly controlled with proper precautionary measures adopted may have adverse impact on the environment especially air since most of the dumps are open (Odeyemi et al., 2011).       

            Microorganisms present in the refuse use the refuse as a food source. Under the anaerobic conditions typical in most dumps, these microorganisms convert the organic material in the refuse to methane and carbon dioxide. As the gas rises through the dump and escapes into the atmosphere, it some-times picks up other compounds. The presence of large amounts of methane in this uncontrolled environment may result in explosions and fires. Additionally, this untreated gas may contain other compounds that pose a substantial health risk to nearby communities (Lewis, and Gattie, 2002). Many microbes can remain viable even after extended periods of time aloft despite the challenges associated with surviving in the atmosphere, including extended UV expo-sure, low moisture levels and extremely oligotrophic condi-tions (Jones and Harrison, 2004). Atmospheric transport is a key mode of microbial dispersal (Stetzenbach et al., 2004) and the transmission of airborne plant and animal pathogens can have significant impacts on ecosystems, human health and agricultural productivity.

            Waste generation and its control have taken an important role in our environment. With the doubling of population and changing lifestyle pattern of the inhabitants the quantity of municipal waste generated is increasing in an alarming rate. Most of this waste is subjected to dumping in a specified disposal yard. The greatest challenge to the environmentalists is the eco friendly management of this waste and application of microorganisms in this context has got an age over other available technologies. Organic waste is consumed by the bacteria, used as nutrients by the bacteria, and is no longer present to produce odors, sludge, pollution or unsightly mess. When bacteria consume waste, they convert the waste into safe by products and in due course of this conversion they actually produce several metabolites to break down the complex waste into simple compounds. Soil microorganisms are increasingly becoming an important source in the search for industrially important molecule (Lewis, and Gattie, 2002). Extent of microbial diversity in nature is still largely unknown, thus there might be many more useful products yet to be identified from soil microorganisms. In soil 80 to 99% of microorganisms remain unidentified whereas these biological communities are known to play a dominant role in maintaining a sustainable biosphere. Today both academic and industrial interest in soil bacteria (due to their several advantages over other microorganisms) is on the rise, in search of deriving these unique biologically active metabolites and novel commercially important products from them (Womiloju, et al., 2003). Bacteria are present in diverse ecological habitats. They are considered highly valuable as they are used in fermentation processes, much as brewing, baking, cheese and butter manufacturing, chemical manufacturing such as ethanol, acetone, organic acid, enzymes, perfumes etc., microbial mining and they produce various antibiotics, vaccines, steroids as well as other therapeutically useful compounds with diverse biological activities. Hence there is an immense possibility to screen effective bacterial strains from waste dump sites with valuable applications. To cope up with the demand for new organisms with properties of production of unique enzymes/ molecules for industrial application and waste degradation there have been a constant effort in isolating novel bacteria from diverse environment (Scarpino, and Quinn, 2010).

            The ever-increasing waste generation in urban cities of developing countries resulting from escalating metropolitan populations has rendered the conventional waste management practices inadequate. The abundance of solid organic wastes in an ever decreasing land space in urban centers has become a nuisance and health hazard. Depletion of organic compounds in farmlands resulting in lower yields and eventual high costs of farm products are obvious. Consequently, there is a need for a technique that would proficiently reduce the volume of waste and convert it into agriculturally usable resource for the amendment of farm lands. It is therefore necessary to adopt an indigenous, innovative, cost-effective and sustainable microbial technology for rapid Municipal Solid Waste composting, given the role the microbes play in the process. In Nigeria, there are colossal volumes of biodegradable wastes in large dumps, which make this proposed microbial Municipal Solid Waste management technique ideal.

1.1       AIM OF STUDY

The main aim of this study is to isolate and characterize indigenous microorganisms from waste dump sites in Umuahia metropolis, while the specific objectives are;

·       To determine the total microbial count of the organisms isolated from indigenous waste dump site in Umuahia.

·       To isolate microorganisms from indigenous waste dump within Umuahia Metropolis

·       To identify possible microorganisms associated with waste dump within Umuahia metropolis

·       To determine the percentage occurrence of various isolates from the waste dump site in Umuahia