Saturday, 18 May 2019

Environmental Biotechnology

Environmental Biotechnology




Environmental biotechnology is the use of living organisms or their products to understand, monitor, and manage the environment. In one sense, this emerging field of biotechnology is simply an extension of natural processes, having been practiced by humans for centuries. Native Americans used many signs of nature to understand and monitor their environment, and they used to fish and other organic nutrients to amend the soil for improved agriculture. Long before scientists could manipulate if DNA, agronomists understood the benefits of crop rotation and planted legumes to rejuvenate fields. Modern wastewater treatment is nothing more than manipulation of natural biosorption and biodegradative mechanisms, compressing waste stabilization in both time and space, and the ancient art of composting has been extended to the degradation of explosives. Many such examples exist, and they all serve to illustrate the point that living organisms or their products have had, and will continue to have, profound effect on the environment. Indeed, were it not for microbial life forms, Earth would be a very different and hostile planet today, completely lacking in oxygen and supporting an atmosphere of toxic gases devoid of an ozone layer.

Microbiologists and, more recently, ecologists and environmental scientists have long speculated about the possibility of exploiting life processes for the purposes of understanding, monitoring and managing the environment. The scientific age brought new insight to the complex interactions between life forms and their environment, and many living monitors, usually called indicators (or bioindicators), were developed to serve as sentinels of environmental change or deterioration. Management of the environment, including the achievement of goals for sustainable development, has been more problematic but will become possible through the judicious application of many technologies, including biotechnology. With the advent of molecular biology and its commercial spin-off, biotechnology, there now exists the potential to more effectively understand, monitor, and even control or manage the environment. Examples of environmental biotechnology applications already enjoying some degree of success include the following:
1. Isolation, amplification, and visualization of genes from environmental samples, for the detection of specific microorganisms or metabolic processes or for monitoring environmental processes;
2. Bioremediation: the use of living organisms to reduce or eliminate environmental hazards resulting from accumulations of toxic chemicals or other hazardous wastes;
3. Bioprevention or bioprocessing of industrial waste streams to remove toxic chemicals or other hazardous wastes, or to convert wastes into useful materials such as commodity chemicals and alternative fuels
4. Biorestoration of altered habitats, including the creation of wetlands, woodlands, and disease-resistant plants and animals

These and other emerging biotechnology research and development ideas hold great promise for application to environmental problems and to opportunities for sustainable development. Although many ideas will no doubt quickly transition to valuable commercial products or processes, others will border on the realm of science fiction. In either event, new ideas must be scientifically investigated for feasibility, and such basic research support will come largely from federal government agencies.

INVESTMENTS AND MARKET TRENDS
In 1994, it was estimated that total biotechnology sales in the United States were 7.7 billion dollars, a 10% increase over the previous year. By 1995, biotechnology revenues in the United States had reached 12.7 billion dollars, an impressive 65% increase over 1994. The vast majority of products sold were, and continue to be pharmaceuticals. Total annual biotechnology sales in the United States are expected to reach 50 billion dollars in the next decade, and the industry is now responsible for approximately 100,000 high-skill jobs generated by 1300 U.S. biotechnology firms. Clearly, biotechnology has captured a significant portion of the U.S. marketplace, and all projections point to a sustained honeymoon for this “high-tech” industry.

Market projections for the environmental component of biotechnology are less definitive. A current estimate for the overall environmental market worldwide is 300 billion dollars annually, although this estimate may be too low because the Environmental Business Journal recently placed the U.S. share alone of this emerging industry to be 170–200 billion dollars in 1994. In 1994, the Organization for Economic Cooperation and Development (OECD) estimated that the world market potential for the biotechnology component of environmental technologies will reach 75 billion dollars by the year 2000. Whatever the environmental biotechnology market becomes over the next decade, the global community fully comprehends its potential, as evidenced by discussions and agreements at the United Nations Conference on Environment and Development in Rio de Janeiro in 1992 and by
recent international investment trends.

In fiscal year (FY) 1995, Japan, through its Ministry of Agriculture, Forestry and Fisheries and its Environment Agency, invested 200 million dollars in biotechnology research and infrastructure related to aquaculture, agriculture, alternative energy sources, and prevention technologies. The Science and Technology Agency of Japan also set aside 4.9 million dollars in FY 1995 to support young researchers (under 35 years of age) at RIKEN and the Research Development Corporation of Japan (JRDC). These and other biotechnology investments in Japan are in keeping with Japan’s desire to increase its international technological competitiveness, including its recent decision to enter the bioremediation marketplace. 

Europe is also hoping to capture a major part of the global environmental biotechnology market. In 1995, Glass et al.placed overall environmental spending in Europe (solid and hazardous waste management, site remediation, air and water pollution control, and various other consulting, engineering, and analytical services) at 84–94 billion dollars. In general, bioremediation and other environmental biotechnologies accounted for only a small percentage of this market. The major exception to this generalization is The Netherlands. In 1995, the Dutch government estimated that the biotechnological component of their 5.4 billion dollars environmental market was 1.4 billion dollars. Germany has a major interest in environmental biotechnology, focused on the cleanup market and driven by increasing government regulation. The German market for bioremediation is presently estimated to be 100 million dollars, and the largest markets are contaminated soil and groundwater, followed by offgas treatment and specialized wastewater treatment.

In 1995, the U.S. National Science and Technology Council (NSTC) released two reports that focused on environmental technologies that will create new jobs while improving and sustaining the environment in the United States [2,5]. Bioremediation alone has been estimated by the National Research Council to become a major environmental biotechnology industry with annual U.S. sales exceeding 500 million dollars by the year 2000. Unfortunately, federal environmental biotechnology investments in the United States have not been commensurate with potential payoffs and with these reports. In FY 1994, the last year for which detailed biotechnology budget numbers are available, the United States invested 90 million dollars in environmental biotechnology research and development. This amount represented 2% of the total FY 1994 4.3 billion dollars federal investment in biotechnology research and infrastructure.

Continued investment in biotechnology research and development, as it pertains to environmental problems and opportunities, is critical to all nations. Such investments will contribute to environmental cleanup and restoration and to the goals for a sustainable future for the United States [1] and for its many international partners in the global marketplace. The purpose of this chapter is to (1) highlight specific examples of successful environmental biotechnology applications, and (2) identify research and development trends in environmental biotechnology. In almost every instance, these applications and trends will benefit agriculture, by providing improved ways to understand, monitor, and manage the environment. The environmental technologies categorized in Technology for a Sustainable Future [1] were avoidance, monitoring, and assessment; control; remediation; and restoration technologies. These four categories are examples of either monitoring or management strategies, and it is implicit that environmental understanding is required for each technology to be successful. Biotechnology can and will be used to accomplish all of these environmental technologies and it will also help provide a better understanding of the environment.

CORPORATE SUCCESS STORIES
A recent report in The Scientist [14] reiterated the plight of small biotechnology companies, which include most of the environmental biotechnology firms. It is becoming increasingly difficult for companies to secure financing, even in the midst of an overall growth climate for the industry, both in the United States and globally [15]. Most small companies are in the development and demonstration stage, lacking a validated product to sell. Consequently, investors are shying away from these small firms, forcing buyouts by larger, more stable companies, or mergers between two or more small start-up companies.

Even so, there are many examples of successful commercial applications of biotechnology being used to investigate and solve environmental problems. Some are at the pilot plant stage and promise to move soon into full production or application. Others are fully operational and are competing well with traditional technologies. Most of these involve bioremediation, especially prevention and biofiltration, although in situ bioremediation of waste sites are beginning to gain a place in the portfolio of accepted remediation technologies. The following examples represent a sampling of “corporate success stories.”

Phytotech, Monmouth Junction, New Jersey, is the first biotechnology company in the world that is devoted to the development and use of plants to accomplish remediation of contaminated sites, a process that has been designated phytoremediation. Toxic metal pollution of soils and sediments is a major environmental problem and one that is tractable to clean up by plants [16]. Phytotech recently conducted field trials in New Jersey and in the Mariupol and Chernobyl regions of Ukraine, using a metal-accumulating cultivar of the mustard plant Brassica juncea [16]. A good accumulation of Pb, Cr, Cd, and Ni from soil was demonstrated, and B. juncea also removed  90 Sr from the soil in Chernobyl. Accumulation of  90 S  by B. juncea was three times greater than accumulation by Zea mays, and the final concentration of  90 Sr in B. juncea shoots was 12 times greater than that in Chernobyl soil. Phytotech is presently investigating several variables that could affect the accumulation of metals and radionuclides, including pH, chelating agents, soil microorganisms, dissolution of soil oxides, an addition of ions, such as phosphate and calcium. Plant extraction (phytoextraction) may never completely remove metals and radionuclides from the soil, but this approach appears to be one of the more promising technologies presently available. It is economical, it will probably leave topsoil in a usable condition for the future, it reduces the amount of contaminant volume to be landfilled or incinerated, and it covers the soil surface during the cleanup process. Disadvantages include the slow nature of the process and the availability of metal-contaminated plants to herbivores—both insects and vertebrates.

Energy BioSystems, The Woodlands, Texas, is presently evaluating a 5-barrel/day, continuous-operation pilot plant designed to remove organically bound sulfur from diesel fuel [17; R.E.Levy, Energy BioSystems, personal communication]. This pilot plant will be used to validate the process and to scale up to a commercial level of 10,000 barrels/day or more. It is estimated that biocatalytic desulfurization will cost 50% less than a traditional hydrodesulfurization unit to install and 10–15% less to operate. The rate of sulfur removal by this Rhodococcus-based bioprocess is presently 45%, and a goal of the pilot plant is to move that rate to near extinction. Clearly, this environmental biotechnology application is well poised to have a profound effect on sustainable development and on reducing sulfur emissions to the atmosphere.

Paques BV, Balks. The Netherlands is a world leader in the development of closed, compact reactors for both aerobic and anaerobic treatment of industrial and domestic wastewaters. Recently, Paques developed a process for the biological removal of zinc and sulfate from the wastewater stream of Budelco, a major Dutch zinc smelter. The process is based on sulfate-reducing bacteria that are present in a submerged, fixed-film reactor. As of this writing, the water treatment plant has been operational for over 3 years. It has a capacity of 300 m 3 /hand removes metals with an efficiency of 99.7% and reduces sulfate below the required 200 mg/ L limit. An additional benefit from this biotreatment process is that Budelco has been able to produce commercially useful zinc and sulfuric acid from the residual process slurry. 

British Nuclear Fuels, Preston, United Kingdom, is in the demonstration and scale-up stage for many environmental biotechnologies relating to microorganism-metal interactions, removal of radionuclides from the environment, and cleanup of nonradioactive heavy-metal pollution. One of their most innovative technologies involves the use of naturally occurring microorganisms to decontaminate concrete and steel surfaces contaminated with actinides or fission products. Contaminated concrete structures are being placed in systems that will promote a biogenic sulfuric acid attack similar to that which occurs in concrete sewer pipes. Formation of a sulfur-oxidizing biofilm (primarily thiobacilli) is encouraged on contaminated concrete surfaces, and the biofilm traps biogenic sulfuric acid between the biofilm and the concrete. Initial studies have shown that up to 10 mm of the surface can be removed from concrete samples in less than 6 weeks. Surfaces treated in this manner can then be more readily removed, treated, and disposed of by convention techniques. This decontamination biotechnology is now being demonstrated as an integrated process in both the United Kingdom and the United States by a Cooperative Research and Development Agreement (CRADA) effort between British Nuclear Fuels and the Department of Energy’s Idaho National Engineering Laboratory [J. Benson and H.Eccles, BNFL, personal communication].

RESEARCH AND DEVELOPMENT TRENDS
A. Extremozymes
Enzymes that catalyze chemical reactions in the presence of reaction conditions that would denature or otherwise deactivate most biomolecules have been termed extremozymes [18,19]. These remarkable enzymes have been isolated from bacteria and archaea that live in extreme environments such as hypersaline waters, deep sea thermal vents, geothermal marine sediments, Antarctic seawater, sewage sludge digesters, acid mine drainage, hot springs, and toxic waste sites. The properties of extremozymes, depending on the enzyme, allowing them to function at pH extremes, temperature extremes, high salt concentrations, high pressure, and high organic solvent concentrations. Clearly, there is a place for extremozymes in industry, but there is also a place in the many facets of environmental biotechnology. Extremozymes can be used to process toxic waste streams and to catalyze reactions in waste tanks that constitute extreme habitats.

Collaborations between microbiologists, enzymologists, and chemical engineers will most certainly lead to novel applications of extremozymes, immobilized or otherwise poised for catalysis. Pure cultures and consortia of extremophiles (or normal microbes that have been genetically engineered to produce extremozymes) will also be useful in processing waste mixtures that contain high salt, high organic solvent, and high metal concentrations, and extremes in pH, pressure, or temperature. In 1996, a new company, Recombinant BioCatalysis, Inc., was formed with the express purpose of cloning and expressing extremozyme genes—including genes isolated from microorganisms that have not yet been cultured—in common mesophilic heterotrophs. This revolutionary start-up company will clone genes from a variety of extremophiles, including hyperthermophiles and psychrophiles, for commercial applications [20].

B. Bioremediation
The use of living organisms to reduce or eliminate hazards resulting from accumulations of toxic chemicals or other hazardous wastes in the environment has been defined as bioremediation [5], Bioremediation has great appeal for many reasons. It is environmentally benign, in the sense that it involves natural biotransformation processes, does not require destructive manipulation of the waste site (e.g., excavation or incineration), and does not usually produce toxic end products. Bioremediation is also more cost-effective than most traditional approaches; start-up costs are usually high, but operational costs are typically very low, resulting in overall lower costs [7,21,22].

Unfortunately, the reliability and predictability of bioremediation have not been validated [23]. There are many basic science and engineering roadblocks that must be overcome before bioremediation becomes both predictable and reliable. Little information is available on gene stability, expression, and exchange in natural environments; most genetic research has been conducted in the laboratory under ideal conditions. Likewise, physiological research has been neglected, and more information is
needed on enzyme induction and repression, metabolic pathways, cometabolism, and other factors involved with the metabolism of toxic chemicals in natural environments. Especially critical is understanding how organisms function when presented with mixed wastes that often include chlorinated solvents, polyaromatic hydrocarbons, heavy metals, radionuclides, chelating agents, and fuel hydrocarbons. These materials solubilize membranes, uncouple reactions, alter enzyme active sites, and in general, wreak havoc on biological processes.

Another area for attention is community ecology; very little is known about how microbial communities respond to wastes in situ. Metabolically competent bacteria may not respond to toxic wastes for a multitude of reasons. Such bacteria could be weathered onto substrate, dormant, or both; they could be capable of degrading one substrate, but remain inactive because of inhibition by other wastes. Presumably, in some situations metabolically competent bacteria are totally absent. All of this involves better understanding of ecology (e.g., species interactions, bioavailability, attachment, and taxis) and geology (e.g., macro- to microheterogeneity, transport, and weathering), not to mention better methods for online, real-time process monitoring and verification. Additional information in all of these areas would allow engineers to optimize biological and geochemical processes and get them
to the marketplace where they could be used to clean up toxic waste sites, eliminate toxically chemicals from waste streams, and even contribute to new waste-free production methods for industry.

C. Bioprevention
Bioprevention is the use of biological processes to remove toxic chemicals or other hazardous materials from industrial waste streams or to convert wastes into useful materials, such as commodity chemicals and alternative fuels. Many of the processes being studied and optimized for bioremediation applications can also be applied to prevention, and these include organic chemical degradation reactions, and heavy-metal and radionuclide transformations (oxidation-reduction reactions). Other prevention processes have been termed “green technologies” because they provide for new environmentally friendly approaches to industrial products and processes.

There now exist several biotechnology alternatives to production processes that in the past involved toxic or otherwise environmentally harmful chemicals. For example, paper manufacturers are now using xylanase enzymes to bleach pulp and, thereby, reduce the amount of chemical bleaching. Mannanases produced by the filamentous fungus Trichoderma reesei are also being used to facilitate pulp bleaching (i.e., to reduce the amount of chlorine needed to achieve brightness) [24]. The textile industry has also employed carbohydrases to process fabrics; for example, the application of cellulases to denim to achieve the effects of stone washing, surface polishing, and softening [24]. Biological detergents now represent the largest industrial application of enzymes, and considerable research is now underway to improve and extend the application and activity of these “green” biochemicals [24].

D. Bioenergy
The search for sources of energy, the recovery of energy, and the delivery and use of energy, all have had and will continue to have, a profound influence on the environment. Strip mining for coal created acid mine pollution of streams, manufactured gas plants left behind a legacy of polycyclic aromatic hydrocarbon (PAH)-contaminated soils and aquifers, the need to convey electricity brought about the development of polychlorinated biphenyl (PCB)-containing transformers, hydroelectric power plants changed the course of streams and forever altered fisheries, numerous supertankers have spilled their contents onto shorelines with catastrophic results, burning fossil fuels increased atmospheric CO 2 and contributed to global climate change, use of nuclear energy has created intractable waste problems, and the list goes on. Although none of these threats can be eliminated in the near future, current research in the area of bioenergy holds great promise for providing cleaner and sustainable sources of energy that will reduce or eliminate many of these liabilities.

Biotechnology may someday reduce CO 2 levels in the atmosphere. There are presently two approaches to biological scrubbing of CO 2 from fossil fuel emissions and from the atmosphere itself. First, photosynthetic microorganisms, primarily microalgae, are being investigated for their ability to convert CO 2 to carbohydrates, ranging from simple sugars to complex polysaccharides. Several candidate organisms have been studied, some of which may produce commercially useful polysaccharides [25]. The Japanese have isolated several marine microalgae that fix CO 2 with high efficiency, and they have coupled pilot algal culture systems with CO 2 - emitting stacks to reduce emissions [26]. One problem with this approach is that the biomass produced, including the biopolymers, such as sugars and polysaccharides, is readily biodegradable and, therefore, could soon be converted back to CO 2 and H 2 O. A solution to this problem is to dry the biomass and use it as a fuel source in power plant boilers, and this too is being investigated by Japanese scientists [26]. The second approach to scrubbing is to develop systems that will biologically remove CO 2 from the carbon cycle. One such approach promotes the growth of marine coccolithophorids at the expense of concrete and atmospheric CO 2 [26]. Coccolithophorids combine bicarbonate ions (from artificial weathering of waste concrete) with CO 2 to produce the calcium carbonate coccoliths associated with these marine algae. Ultimately, coccoliths settle, become part of the ocean floor sediment, and, therefore, serve as a long-term sink for inorganic carbon.

Biohydrogen is the term being used to describe photosynthetic production of hydrogen gas. When H 2 is combusted for energy, H 2 O is the only product. Clearly, this alternative energy source would reduce the CO 2 emissions associated with fossil fuel combustion and could represent a sustainable source of clean energy for the future. Biohydrogen involves visible light energy as the driver of reduction processes that are catalyzed by either hydrogenase or nitrogenase to produce H 2. The system receiving the most attention is the ability of heterocystous cyanobacteria to split water into H 2 and O 2 [27,28], although a mutant strain of the green alga Chlamydomonas reinhardtii is now being investigated by scientists at the Oak Ridge National Laboratory [29]. Much work needs to be done before production efficiencies can be maximized and cost-effectiveness realized. Even so, there is great interest in biohydrogen as a sustainable alternative source of energy.

Biodiesel is another biological approach to alternative energy, and there are presently two ways to produce “bio-based” diesel fuel. First, vegetable oils and waste oils from restaurants and other food processors are now being used as sources for diesel fuel. In 1993, this type of biodiesel was being used extensively in Europe, with a production capacity of 32 million gals yr (30). Soybean-derived diesel is presently undergoing commercial trials in the United States. Early indications are that particulate emissions are reduced with biodiesel, and there is no organosulfur r component in biodiesel. However, the low cost of petroleum-derived fuels in the United States will not soon create a market for biodiesel. The second method of production involves culturing marine microalgae to obtain lipids that can be converted to biodiesel, and the National Renewable Energy Laboratory (NREL) has conducted extensive research in this area. For example, NREL investigators have recently cloned a gene (acetyl-CoA carboxylase) from the marine diatom Cyclotella cryptic that they believe is involved with the rate of fatty acid biosynthesis [30]. It is hoped that this and related genetic-engineering approaches can be used to enhance the ability of microalgae to produce lipids for biodiesel.

E. Biosensors
The use of biomolecules and biological processes to activate a molecular transducer that, in turn, will signal the occurrence of an event or the presence of material has evolved into a sophisticated industry. Biosensors were first used in clinical applications and included fluorescent antibodies (immunoglobulins conjugated to fluorochromes) and enzyme-based immunoassays (immunoglobulins bound to enzymes that catalyze substrate to produce a colored product) to detect pathogenic microorganisms and microbial toxins. Today, many routine tests in the clinical laboratory are based on biosensors. 

Biosensor technology has expanded to environmental interrogation, and now includes many different approaches, ranging from antibody-based detection of proteins to gene probes for specific microorganisms, to the use of acetylcholinesterase for pesticide detection. A new generation of biosensors is based on a technology called reporter genes. Reporter genes have largely resulted from recombinant DNA technology, and involve the insertion of a gene or genes into the DNA of an organism that one wishes to monitor or track in the environment. The first and most successful of the reporter genes was lacZ, a gene in the lactose (lac) operon that codes for the production of ß-galactosidase. When lacZ is expressed, it hydrolyzes disaccharide-like compounds to produce highly visible colored products. Other reporter genes include the ice nucleation gene (inaZ), the ß-glucuronidase (gusA) gene, and the sky/E gene from the TOL plasmid [7,31].

A novel reporter that is currently enjoying increased popularity is the luciferase or bioluminescence system of marine Vibrio species. When lux genes are inserted into an operon of interest, downstream from the promoter of the operon, the recombinant organism emits visible light when the operon is induced. A project at the University of Tennessee’s Center for Environmental Biotechnology and the Oak Ridge National Laboratory’s Center for Biotechnology is focusing on a lux gene construct (Pseudomonas fluorescens HK44) that naturally degrades the PAH naphthalene. In the presence of naphthalene, HK44 emits a visible light that can be quantitatively measured with fiber-optic photometry, and the bioluminescence is directly proportional to both the biomass of HK44 and substrate (i.e., naphthalene) concentration. A mathematical model (second-order rate equation) has been developed that accurately describes the activity of HK44, and model predictions have been within 3% of actual degradation rates measured for a wide range of substrate/biomass ratios and operating conditions. This bioluminescence reporter technology is being field tested in large lysimeters (contained 8-ft-diameter ×10-ft-deep [2.4-m×3-m] stainless steel cylinders developed by the Department of Energy for studying radioisotope leaching in landfills) at the Oak Ridge National Laboratory Y-12 Facility. Both free HK44 cells and cells contained in biosensor probes [32] will be evaluated. The lysimeters will provide a scale that is sufficient for efficacy, cost, and risk analysis of this biotechnological approach to toxic waste remediation. If successful, bioluminescence reporter technology will be a valuable tool for online, real-time bioremediation process monitoring and validation. It may also prove useful as a surrogate for bioavailability testing because the substrate must move into the bacterial cell and induce an enzyme system for bioluminescence to occur.

F. Biodiversity
Recent evidence suggests that there are countless “yet-to-be-cultured” eubacteria and archaea present in the biosphere, awaiting developments in microbial culture technology so that they can be isolated and described. Bull et al. [33] estimated the total number of bacterial species to be 40,000. In a recent paper on microbial diversity, Tiedje [34] pointed out that different lines of evidence suggest that between 300,000 and 1-million species of bacteria inhabit the Earth, yet Bergey’s Manual of Systematic Bacteriology (four volumes containing 2784 pages) lists only 3100. Extrapolation of this hypothesis suggests that Bergey’s Manual, at least in a contemporary format, could ultimately reach 400–1300 volumes in length! Soil alone may contain 10,000 species per gram, based on the heterogeneity of DNA extracted from soil samples [34]. The oceans of the world contain countless picoplankton that is yet cultured. For example, the cold water archaea, first detected in seawater samples from depths ranging from 100 to 500 m [35,36], are now believed to constitute a substantial percentage of the total bacterial biomass present in oceans throughout the world [37]. These archaea have not been isolated in pure culture, grown, and phenotypically described; they have been detected
only by means of polymerase chain reaction (PCR) amplification, characterization, and classification of their ribosomal RNA. Woese recently noted that approximately 300 archaeal species have been described in the literature, and believes that this number will balloon (C.R.Woese, personal communication). Boone has stated that methanogens alone have accounted for five to ten new species per year for the last 10 years (D.R.Boone, personal communication). It is doubtful that all of these yet-to-be cultured archaea and eubacteria are dormant in their respective habitats; some must be active and involved in biogeochemical cycling in unknown ways. This hypothesis is supported by extensive circumstantial evidence; for example, data provided by vital staining techniques such as the AODC, direct viable counting [38], and INT staining [39]. Given their presumed relative abundance, and community structure shifts in response to environmental disturbance [40], yet-to-be-cultured archaea and eubacteria no doubt transform vast quantities of chemicals in the biosphere. Clearly, the diversity of microbiota as it becomes known will provide the basis for many new environmental biotechnologies, including biotechnologies for understanding, monitoring, and management.

BIOTECHNOLOGY FOR SUSTAINABLE DEVELOPMENT

It has been the intent of this chapter to articulate the place of biotechnology in the bridge to a sustainable future. Environmental technologies have been identified as the building blocks for that bridge [1,2], and they are key to the achievement of long-term environmental, energy, and economic goals, not only for the United States but for all nations of the world. Sustainable development has been defined as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs” [1]. Without doubt, biotechnology is well poised to play a significant, if not the lead, role in that development.

I was in my final year of graduate school when the first Earth Day was celebrated on April 22, 1970. The tools of molecular biology were beginning to come online, but modern biotechnology had not yet been born. There was a growing concern over environmental problems, and both policymakers and industry were making inroads toward solving past problems and anticipating future technology’s effects [2]. Most attention, however, was focused on “end-of-pipe” equipment for controlling discharges to the atmosphere and waterways; little or no attention was being given to biological treatment and prevention, and it was the prevailing attitude in 1970 that new biological processes being studied in the laboratory (e.g., pesticide and PCB degradation) could not be successfully introduced to established ecosystems (e.g., farm fields and river bottoms). The ensuing 25 years have witnessed profound changes in this philosophy, and biotechnology has come of age.

On Earth Day 1995, the place of biotechnology in developed nations was well established. For the first time, a biotechnology company had been awarded the Presidential National Medal of Technology, the highest honor given in the United States for achievement in science and technology. Amgen had received the award in December 1994, for bringing two widely successful medicines (epoetin alfa [EOGEN] and filgrastim [NUPOGEN]) to market. Clearly, biotechnology had become a major driver in the pharmaceutical industry and on Wall Street. As outlined in this review, biotechnology is also rapidly becoming a major driver in the environmental marketplace—nationally and globally. Only a sampling of the emerging environmental biotechnologies have been discussed in this chapter, but they illustrate a trend. The future of environmental understanding, monitoring, and management lies in biotechnology, and through aggressive application and attention environmental biotechnology will help build the bridge to a sustainable future for all humankind.

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