Advances in Environmental Biotechnology

Environmental biotechnology is a coordination of scientific and engineering acquaintance associated with the use of microorganisms and their degraded products after treatment in the prevention of environmental pollution through biotreatment of wastes and biomonitoring of environment and treatment processes. Environmental biotechnology is the multidisciplinary combination of sciences and engineering in order to employ the enormous biochemical efficacy of microorganisms and plants, for the restoration and perpetuation of the environment and for the sustainable utilization of resources. The most significant considerations for purpose of biotechnology in waste treatment are technically and economically sound for biodegradability or detoxification of substances during biotechnological treatment, huge amount of treated wastes, and capability of natural microorganisms to degrade substances. The unique role of environmental biotechnology in the future is intensified taking into account the possibilities to append with innovative solutions and guidelines in remediation of environments contaminated with pollutants, minimizing future waste release and creating pollution prevention alternatives.

Since the onset of industrial revolution is up till the recent surge in technological processes, environmental pollution has grown at an alarming rate causing distress to living beings and irreplaceable damage to the earth. With the recognition of the severity of this environmental damage and increase in interest of using technological advancement, a number of successful pollution control strategies have emerged over the years. However, the measurement and quantification of environmental pollution is the most pragmatic first step for identifying various management and mitigation strategies to control environmental pollution. This chapter aims to study a range of proven measurement techniques for quantitatively determining the concentration of various environmental pollutants in the atmosphere. This is particularly important in the formulation of cost-effective control measures and strategies for environmental pollution. Furthermore, to elucidate the concept of pollution measurement, certain parameters which are considered of high importance for environmental monitoring and reflect the quality of a healthy (or unhealthy) environment, especially with respect to soil, water and air, are also discussed in the initial parts of the chapter.

Water is one of the basic needs of a living organism to sustain life on earth. But due to the rapidly increasing population, urbanization, and industrialization, the quality of portable water is depleting. If the wastewater is not treated efficiently, then it generates a number of problems such as malodor and health problems, gives birth to disease-causing agents, etc. Therefore, it is the need of the day to develop some new techniques which are more efficient in treating the wastewater. In this chapter, the use of new techniques such as membrane bioreactor, advanced oxidation techniques and nanotechnology for the treatment of wastewater have been discussed. The nanocomponents such as nanosorbents, nanocatalysts, molecularly imprinted polymers (MIPs), and nanostructured catalytic membranes (NCMs) are the recent techniques which treat wastewater very efficiently. The water recovered after these treatments meet the human consumption criteria.

Wastewater treatment has become compulsory by government regulations in most parts of the world owing to the importance of maintaining the sanitation of freshwater and preserving the environment. Bioreactors are the core of any biotechnology-based process for enzymatic or microbial biotransformation, bioremediation, and biodegradation. This present chapter summarizes the perspective of the most concerning widespread reactors, such as rotating biological contactor, biological fluidized bed reactor, packed bed reactor, membrane bioreactor, continuous stirred tank bioreactor, upflow anaerobic sludge blanket reactor and photobioreactor, etc., that are most commonly used for treatment of different industrial wastewater. The performance studies of bioreactors carried out by different researchers have also been reviewed.

Bioremediation technology involves the use of living organisms like microbes and plants to reduce/degrade, eliminate and transform contaminants present in soils, sediments and water. The technology has gained wider acceptance in the recent years because of its potential to remove various organic and inorganic contaminants from various components of the environment. The technology provides an effective treatment of inorganic and organic contaminants under in situ and ex situ conditions by natural means. Potential of microbes and plants both have been exploited to achieve maximum removal/remediation of inorganic and organic contaminants. The biotechnological approaches and genetic engineering strategies have been employed by researchers to improve the efficacy of this technique for achieving complete degradation of contaminants. Enhancement in potential of both plants and microbes for achieving complete remediation of one or more than one pollutant can prove an asset for remediating contaminated sites. The present chapter highlights the role of microbial and phytoremediation in removal of pollutants from the environment.

Wastewater from the textile industry contains significant amounts of synthetic dyes that require treatment to prevent groundwater contamination. These synthetic dyes are stable and are highly persistent in nature. The search for innovative, cost-effective, and environment-friendly technologies has become the real challenge in recent years. In view of the need for a technical and economically satisfying treatment technology, a flurry of emerging technologies has been proposed and examined at different stages of commercialization. Appliance of biotechnological techniques in recent period emerged as a very promising area for decolorization of textile wastewater, i.e., targeted at breaking down the dye molecule to basic elements (mineralizing them), and has much less environmental impact than conventional methods. A lot of research in this field revealed the existence of a variety of microbial communities capable of decolorizing a wide group of dyes. This chapter reviews the usage of various microorganisms such as bacteria, fungi, algae, and microbial consortium as free cells or in immobilized form for the decolorization of different types of textile dyes. The performance and results of latest research studies with pure and mixed cultures in various reactors have been also compiled pertaining to the bioremediation of dyes and colorants from wastewater with the possible alternative emerging technologies.

Tannery effluent is a serious environmental threat due to its high chemical levels which include salinity, organic load (chemical oxygen load or demand, biological oxygen demand), inorganic matter, dissolved and suspended solids, ammonia, total Kjeldahl nitrogen, sulfide, chromium, chloride, sodium and other salt residues, heavy metals, etc. These components present in the effluent affect agriculture, human beings and livestock. Exposure to chromium and other pollutants in tannery effluent increases the risk of dermatitis, ulcer, nasal septum perforation and lung cancer. The environmental protection regulations stipulate that industries are not allowed to emit sulfide and chromium in the wastewater. Thus, removal of these high-strength toxic chemicals from the wastewater is very important. Treatment of tannery wastewater is carried out by physical, chemical, biological, or combination of these methods. Biological treatment of wastewater is more favorable and cost effective as compared to other physiochemical methods. A number of bioremediation strategies have been reported in the recent past showing their potential in the treatment of tannery effluent. The present review summarizes the recent advances in bioremediation of tannery effluent.

In today’s era of rapid globalization, sustainability in the environment has become a priority for world leaders; they affirm their intent to pursue broad range of technologies with the potential to reach the goal of sustainability. Human interferences in terms of their increasing anthropogenic activities, destructive behavior, resource exploitation fueled by growing consumption, and swiftly eroding natural ecosystems are driving us toward an environmental precipice. Today’s environmentalists remain alarmed at the inefficient use of technologies by mankind. Therefore, to cope up with this alarming situation, the recent advances in “biotechnology” played an important role. Some of the defining technologies of modern biotechnology with the probability of attaining the goal of sustainability are included in fields like food production, various industrial and agricultural practices, capturing valuable products from renewable raw materials, energy sources, waste management, and bioremediation. This chapter addresses the challenges ahead and various strategies that can be dealt with to achieve a sustainable environment.

With the increasing industrialization and urbanization, the environment is getting polluted. Conventional techniques such as filtration, centrifugation and biological treatment are expensive and not efficient one. Therefore, there is a need for the development of recent and efficient techniques for environmental monitoring and treatment. Nanotechnology is the solution to the abovesaid problems. Nanoparticles, nanomembranes, nanofilters, and nanocatalysts have been developed for wastewater treatment. These have smaller size (1–100 nm) and higher surface area to volume ratio. Due to these properties, they provide more reaction surface which results in increased efficiency and selectivity. With the some issues solved, nanotechnology will answer all the environmental problems.

Chemicals in the form of fertilizers and pesticides have been used in boosting agricultural productivity and crop protection since years. The adverse effects such as environmental toxicity and long residual action resulting from excessive use of these chemicals have prompted the search for nontoxic eco-friendly biological agents. Microbes have emerged as eco-friendly alternate to achieve enhanced plant productivity and protection. Microorganisms colonize rhizosphere/interior of the plant, thereby promoting growth of plants by increasing the availability of essential nutrients such as nitrogen and phosphorus and providing growth regulators. Microbes and their supplements also provide protection against various pests and pathogens. Biofertilizers and biopesticides serve as an eco-friendly substitute to toxic chemicals and form an important component of integrated nutrient management system. Efficiency of both biopesticides and biofertilizers can be increased by molecular approaches. The present chapter highlights the role of biofertilizers and biopesticides in crop improvement and hence achievement of sustainable agriculture.

Increasing concern about the environment, food and feed shortages, and hike in the price of petroleum has stimulated interest in the new ways of producing more bioenergy. The interest is rapidly increasing toward converting agricultural and industrial wastes to commercially valuable products. Waste disposal and pollution are inextricably linked. Unwanted residues that are usually perceived to be of negative value are described as waste. The production of citrus juice on an industrial level leads to a considerable quantity of solid and liquid residue (8–20 million tons year⁻¹), which is considered as waste. Citrus processing residues possess no economic value. They are rich in soluble sugars, cellulose, hemicellulose, pectin, and essential oils that could form the basis of several industrial processes. Possible applications of these waste residues include fertilizer, cattle feed, charcoal, adsorption of chemical compounds, bioethanol production, and extraction of essential oils and pectin.

The majority of waste disposal situations involve pollution of various kinds. Thus, the solid wastes and its disposal is one of the serious problems in developing countries, which require eco-friendly treatment options. The bioethanol made from citrus waste biomass can offer immediate and sustained greenhouse gas advantages and also solve the problem of its disposal. The study proposes alternatives for the minimization and recovery of solid and liquid residues generated in the production of citrus processing with a view of industrial plants for its reuse and value addition, thus saving environment from its hazards.

Heavy metals are natural constituents of the earth’s crust. There is a significant alteration in the geochemical cycles and biological balance of these heavy metals due to various anthropogenic activities. These anthropogenic activities result in the release of bioavailable forms of various heavy metals such as mercury, lead, cadmium, nickel, copper, zinc, etc. into soil and aquatic environments. Prolonged exposures to these heavy elements lead to harmful health implications on different domains of terrestrial and aquatic life. Due to several limitations associated with physical and chemical methods for remediation of contaminated sites, bioremediation has been explored these days as an alternate technology for treatment of heavy metal pollution in soil and water. Various microorganisms such as bacteria and fungi along with plants play a vital role in biotransformation of these heavy metals into nontoxic forms, through processes such as bioremediation and phytoremediation, respectively. Recent progress in genetics has provided the driving force toward the use of engineering improved microbes and enzymes for bioremediation. Keeping these future remediation tolls in mind, present review investigated the abilities of wild microorganisms and plants in terms of tolerance and biotransformation of heavy metals along with their genetically engineered counterparts to explore these immense and valuable biological resources for bioremediation.

Agricultural biotechnology is the area of biotechnology involving applications to agriculture. Agricultural biotechnology has been practiced for a long time, as people have sought to improve agriculturally important organisms by selection and breeding. In the twentieth century, breeding became more sophisticated, as the traits that breeders select for include increased yield, disease and pest resistance, drought resistance and enhanced flavor. Traits are passed from one generation to the next through genes, which are made of DNA. Based on an understanding of DNA, scientists have developed solutions to increase agricultural productivity. Starting from the ability to identify genes that may confer advantages on certain crops and the ability to work with such characteristics very precisely, biotechnology enhances breeders’ ability to make improvements in crops and livestock.

The rapid increase in the environmental contaminants due to various anthropogenic activities has become a serious issue worldwide. New and efficient measures are explored to remove or contain the threat from the increasing levels of environmental pollution. Plant-based soil and water remediation (phytoremediation) is one such method which can prove to be a sustainable and promising treatment to remediate environmental problems. Phytoremediation exploits the abilities of green plants to uptake, stabilize, or metabolize the pollutants. Moreover, it is a cost-effective and environmentally safe approach as compared to conventional methods to solve the problems of soil and water pollution. Phytoremediation technique has been successfully applied to treat various contaminated sites and pollutants such as heavy metals, dyes, fly ash, hydrocarbons etc. and furthermore, research is underway for exploring new ways to improve the phytoremediation process.

Pesticides, although proving as a fast remedy in pest control, are polluting the environment in a number of ways acting as havoc to mankind and environment. The presence of pesticides above tolerance level has raised concerns about their removal from soil and environment through novel ways like microbial bioremediation. The present book chapter highlights about the microorganisms and their degradation pathways used in removal of a number of pesticides like carbendazim, chlorpyrifos, endosulfan, and sulfosulfuron. There are a number of living and nonliving factors such as pH, temperature of soil, and availability of degrading microbes. Research has been done on isolation of pesticide-degrading microbes, which could act as an efficient and novel bioremediation agents in the future like Brevibacillus borstelensis and Streptomyces albogriseolus that have the ability to remove carbendazim and sulfosulfuron.

Biosensor is an analytical tool that consists an immobilized biological component to react with analyte; subsequently, the produced biological signal is converted to a readable signal with the help of a transducer. Biosensors are of great importance because of their several advantages over the conventional techniques in the field of analysis. Biosensors are researched and applied in several diverse areas, such as health, medicine, defense, agriculture and food safety, industry and environmental monitoring, etc. Present chapter provides an overview of application of biosensors in the field of environmental analysis and monitoring. Strategies developed involving different biocomponents, bioassay principle, transducers, and their application for different groups of analytes; for example, pesticides, BOD, heavy metals, and other categories of environmental pollutants have been discoursed. Future trends and commercial aspects of environmental biosensor have also been discussed.