Environmental Microbiology (eBook)

Terry Gentry, Charles P. Gerba, Ian Pepper (Herausgeber)

eBook Download: PDF | EPUB

2014 | 3. Auflage
728 Seiten
Elsevier Science (Verlag)
978-0-12-394817-5 (ISBN)

Infos

Designed for advanced undergraduate students, graduate students, and environmental professionals, this book builds upon the tremendous success of the previous editions with a comprehensive and up-to-date discussion of environmental microbiology as a discipline that has greatly expanded in scope and interest over the past several decades. From terrestrial and aquatic ecosystems to urban and indoor environments, this edition relates environmental microbiology to a variety of life science, ecology, and environmental science topics including biogeochemical cycling, bioremediation, environmental transmission of pathogens, microbial risk assessment, and drinking water treatment and reuse. The final chapter highlights several emerging issues including microbial remediation of marine oil spills, microbial contributions to global warming, impact of climate change on microbial infectious disease, and the development of antibiotic-resistant bacteria. - Presents state-of-the-art research results with key, recent references to document information - Emphasizes critical information using 'Information Boxes' throughout - Includes real-world case studies to illustrate concepts, along with frequent use of graphics, cartoons and photographs - Offers questions at the end of each chapter designed to test key concepts - Lecture slides available for instructors online

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Designed for advanced undergraduate students, graduate students, and environmental professionals, this book builds upon the tremendous success of the previous editions with a comprehensive and up-to-date discussion of environmental microbiology as a discipline that has greatly expanded in scope and interest over the past several decades. From terrestrial and aquatic ecosystems to urban and indoor environments, this edition relates environmental microbiology to a variety of life science, ecology, and environmental science topics including biogeochemical cycling, bioremediation, environmental transmission of pathogens, microbial risk assessment, and drinking water treatment and reuse. The final chapter highlights several emerging issues including microbial remediation of marine oil spills, microbial contributions to global warming, impact of climate change on microbial infectious disease, and the development of antibiotic-resistant bacteria. - Presents state-of-the-art research results with key, recent references to document information- Emphasizes critical information using "e;Information Boxes"e; throughout- Includes real-world case studies to illustrate concepts, along with frequent use of graphics, cartoons and photographs- Offers questions at the end of each chapter designed to test key concepts- Lecture slides available for instructors online

Textauszug

Chapter 1

Introduction to Environmental Microbiology

Ian L. Pepper, Charles P. Gerba and Terry J. Gentry

This chapter provides an introduction to environmental microbiology as a discipline. It also illustrates the significance of environmental microbes to our daily lives in terms of not only the overall health of the planet, but also: what infects us; what heals us; what we drink; what we eat; and what we breathe. Following this, a discussion of emerging microbial issues is presented, including detrimental microbial pathogenic outbreaks as well as beneficial microbial bioremediation success stories. Finally are presented some of the latest and most advanced techniques and methodologies that are revolutionizing modern environmental microbiology through state-of-the-art science.

Keywords

environmental microbiology; microbial bioremediation; microbial natural products; microbial pathogens; mycotoxins; next generation sequencing; rhizosphere microorganisms

Outline

1.1 Environmental Microbiology as a Discipline

1.2 Microbial Influences on our Daily Lives

1.2.1 Overall Health of the Planet

1.2.2 What Infects Us

1.2.3 What Heals Us

1.2.4 What We Drink

1.2.5 What We Eat

1.2.6 What We Breathe

1.3 Environmental Microbiology in 2014

Questions and Problems

References and Recommended Reading

1.1 Environmental Microbiology as a Discipline

We define “environmental microbiology” as the study of microbes within all habitats, and their beneficial and detrimental impacts on human health and welfare. Environmental microbiology is related to, but also different from, “microbial ecology,” which focuses on the interactions of microorganisms within an environment such as air, water or soil. The primary difference between the two disciplines is that environmental microbiology is an applied field in which we attempt to improve the environment and benefit society. Environmental microbiology is also related to many other disciplines (Figure 1.1).

Figure 1.1 Environmental microbiology interfaces with many other disciplines.

Microorganisms occur everywhere on Earth. An adult human body contains 10 times as many microbial cells as mammalian cells, consisting of approximately 1.25 kg of microbial biomass (Wilson, 2005). Although the study of microbial inhabitants of humans resides within clinical microbiology, it was the discovery of environmental pathogenic microorganisms that invaded the human body that resulted in the beginning of environmental microbiology. These roots were enabled by the work of Louis Pasteur and Robert Koch, who developed the Germ Theory of Disease in the 1870s, following which, the presence of waterborne human pathogens then became the initial focus of environmental microbiology. In developed countries, applied environmental studies related to drinking water and wastewater treatment dramatically reduced bacterial waterborne disease. However, other microbial agents such as viruses and protozoa, which are more resistant to disinfection than enteric bacteria, still cause problems, resulting in water quality continuing to be a major focus in environmental microbiology. There is an estimated 20,000,000 cases of illness per year due to drinking contaminated water (Reynolds et al., 2008). The largest waterborne outbreak of disease in the United States occurred in 1993, when over 400,000 people became ill and around 100 died in Milwaukee, Wisconsin, due to the protozoan parasite Cryptosporidium (Eisenberg et al., 2005). In developing countries, poor sanitation resulting from a lack of water and wastewater treatment still results in millions of deaths annually.

Controlling the contamination of our food supply also continues to be a concern; and the Centers for Disease Control estimates that in the United States each year there are 48 million cases with 128,000 people hospitalized and 3000 deaths. The third most deadly outbreak of foodborne infection in the United States occurred in 2011, when 29 persons died from Listeria contamination of cantaloupe. Information Box 1.1 documents some of these foodborne outbreaks.

Information Box 1.1

Large-scale Food Recalls Due to Foodborne Outbreaks

Until the middle of the 20th century, industrial chemicals in the United States were routinely disposed of by dumping them into sewers, soils, rivers or oceans, without regard to the pollution that this caused, or the subsequent adverse ecological and human health effects. This all changed in the 1960s when concern over a toxic dump was highlighted by Rachel Carson’s landmark book Silent Spring. In essence, this resulted in the birth of the environmental movement in the United States, and a new field of study for environmental microbiology known as “bioremediation.” Many chemicals discharged into the environment without regard to the consequences have been shown to result in adverse human health impacts. However, since hydrocarbons, chlorinated solvents and most pesticides are organic in nature, they can potentially be degraded by heterotrophic microorganisms including bacteria and fungi. The field of bioremediation within environmental microbiology involves enhancing and optimizing microbial degradation of organic pollutants, resulting in environmental cleanup and reduced adverse human health effects. The efficacy of bioremediation was demonstrated in 1989, when the Exxon Valdez oil tanker spilled approximately 11 million gallons of crude oil into Prince William Sound. Optimization of bioremediation was a major factor in cleaning up and restoring Prince William Sound. Bioremediation has also been shown to be critically important in cleaning up the more recent 2010 Gulf of Mexico oil spill (see Chapter 31).

Also in the 20th century, soil microbiology, a component of environmental microbiology, became important as a means to enhance agricultural production. Studies on the rhizosphere (the soil surrounding plant roots), and specific studies on root-microbial interactions involving nitrogen fixing rhizobia, and mycorrhizal fungi that enhanced phosphorus uptake, were all utilized to improve plant growth. Other studies of plant growth-promoting bacteria that reduced the incidence of plant pathogens were also effective in aiding the “Green Revolution,” which resulted in stunning increases in crop yields throughout the United States and in many parts of the world. Overall, these fundamental study areas have helped shape the current discipline of environmental microbiology, and all affect our everyday life.

1.2 Microbial Influences on our Daily Lives

Some of the influences that microorganisms have on our daily lives are shown in Table 1.1. These influences can be summarized in terms of:

• The overall health of the planet

• What infects us

• What heals us

• What we drink

• What we eat

• What we breathe

Table 1.1

Microbial Influences on Our Daily Lives

1.2.1 Overall Health of the Planet

Life on Earth depends on the biogeochemical cycles that are microbially driven. For example, carbon dioxide is removed from the atmosphere during photosynthesis by both plants and photosynthetic microbes. The result of this process is that carbon dioxide is converted into organic carbon building blocks as plant or microbial biomass, which ultimately results in the formation of organic matter. Fortunately, this organic matter is ultimately degraded by microorganisms via respiratory processes, which again release carbon dioxide into the atmosphere. Without microbial respiration, a vast array of organic matter would accumulate. Similar biogeochemical processes exist for all other elements, and are also driven by microorganisms. All life on Earth is dependent on these biogeochemical cycles. In addition, these cycles can benefit human activity, as in the case of remediation of organic and metal pollutants, or be detrimental, as in the formation of nitrous oxide which can deplete Earth’s ozone layer (Ravishankara et al., 2009).

A major indirect effect of environmental microbes may be the influence of soil microbes on global warming. However, currently there is still debate about the net impact of microbes on this process (Rice, 2006). Soils can be a source of “greenhouse gases” such as carbon dioxide, methane and nitrous oxide due to microbial respiration, or they can be a sink for carbon due to enhanced photosynthetic activity and subsequent carbon sequestration. Although the debate has yet to be resolved, it is clear that even relatively small changes in soil carbon storage could significantly affect the global carbon balance and global warming. In turn, many scientists believe that continued global warming will ultimately have catastrophic impacts on human health via extreme weather events and natural disasters.

1.2.2 What Infects Us

Humans are subject to microbial attack from a plethora of pathogens that can be viral, bacterial or protozoan in nature (Table 1.2). Likewise, the route of exposure is variable and can be through ingestion or inhalation of contaminated food, water or air, or from contact with...

Produkt-Details

• Erscheint lt. Verlag: 1.3.2014
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Biologie ► Mikrobiologie / Immunologie
• Themenwelt: Naturwissenschaften ► Biologie ► Ökologie / Naturschutz
• Themenwelt: Technik ► Umwelttechnik / Biotechnologie
• ISBN-10: 0-12-394817-7 / 0123948177
• ISBN-13: 978-0-12-394817-5 / 9780123948175