Soil Bioremediation

Soil bioremediation is a process whereby microorganisms, plants, or microbial or plant enzymes utilize chemical contaminants in the soil as an energy source and, through oxidation–reduction reactions, metabolize the target contaminant into useable energy for living organisms such as microbes. There has been a rise in the past few decades on environmental pollution as a result of rapid industrialization, increased human activities on energy and unsafe agricultural practices. Soil pollution which is the contamination of soil with anomalous concentrations of toxic substances is one of the serious major environmental challenges. The soil harbours pollutants of many health hazards such as hydrocarbons with benzene increasing the risk of contracting leukaemia, others include pesticides, heavy metals, nuclear wastes, asbestos, etc. Hence, bioremediation which is eco-friendly seems as a sustainable technique for soil pollution management. However, a more comprehensive understanding is advocated for enhanced removal of every form of contaminant including recalcitrant pollutants.

Heavy metals, organic pollutants, and hazardous substances are accumulating in soil due to human activities in industry, agriculture, and urbanization. As economies grow, strategies are needed to reduce chemical inputs, remediate contaminated lands, and raise awareness about responsible land management practices. Bioremediation, which employs microorganisms to degrade soil contaminants, shows promise as a remediation approach. These microbes can break down complex organic pollutants and transform metal contaminants. Bioremediation can be performed in situ or ex situ depending on site constraints and contaminant characteristics. Challenges include slow progress under ambient conditions and the need for nutrients, water, and oxygen input. In addition, constant monitoring is crucial for efficacy and safety. Whereas, bioremediation offers a sustainable and energy-efficient alternative when combined with physical and chemical methods. Cutting-edge microbiology technologies emphasize efficiency through tailored microbes and optimized biostimulation strategies. This chapter addresses soil contamination and the environmental advantages of microbial remediation.

Bioremediation is a process of using living organisms, generally, microorganisms, to break down and remove or detoxify contaminants from the environment, degrading or transforming toxic substances into less harmful or non-toxic substances. It may be applied to a wide range of environmental pollutants, including hydrocarbons, pesticides, heavy metals, and other hazardous chemicals. Meanwhile, biocontrol is the use of living organisms to control pests or invasive species that can cause damage to crops, natural habitats, or other ecosystems.

Soil is the floor on which maximum living organism depends for its survival. The largest producer i.e. plant depends on soil for of its nutrient and water. The health of the soil is the utmost important to healthy life of the living organism as the health of the soil also directly or indirectly affects the air and water also. Due to non-eco-friendly anthropogenic activity large soil has been degraded worldwide. So, reviving the soil has become an important subject today. Soil Remediation is technique that revives the contaminated soil unfit to support or toxic to plant to fit and less toxic condition that can support healthy growth of plants. Many traditional methods have been adopted by people but they are environmental infeasible or non-economical. In the last decade people adopted scientific technique and environmentally sustainable method to revive the degraded soil. This chapter will explain eco-friendly biological means of soil remediation with special focus on phytoremediation, Bioremediation, Vermiremediation and Mixremediation.

Remediation technologies are essential sustainable solutions for pollutants recovery from different rich and varied soils especially with the rapidly increasing population and the related anthropogenic activities. Unfortunately, majority, if not all, traditional physicochemical methods of soil remediation are often predicated on environmentally-destructive and/or economically-infeasible techniques. Consequently, there is the development of more innovative and sustainable eco-friendly biological methods of soil remediation termed Gentle Remediation Options (GROs). This doesn’t just reduce the concentration of soil contaminants below regulatory limits but maintains the legally-and ethically-required minimization of risk for human and environmental health, concurrently creating a recovery of soil health amongst others. GROs often bring environmental, economic and social benefits by integrating the biological remediation options such as phytoremediation, vermiremediation and bioremediation with the creation of economic revenues. It is expedient to look into future prospects of recent technologies such as combining GROs with nanoremediation in mitigating contaminated soils for optimum results.

The term “soil pollution” refers to the act of contaminating soil through a wide range of anthropogenic (agricultural, industrial, and wastewater) activities. These activities add nutrients, pesticides, and sediments to the soil, whereas industry and urbanization also contaminate the soil by dissipating solid waste, heavy metals, solvents, and other slow degrading organic and inorganic materials. Heavy metals and metalloids can build up in soil and have potentially hazardous impacts on ecosystems and human health, endangering the sustainable use and management of soil resources. While there are a number of remediation technologies that can be used to immobilise, remove, or detoxify heavy metals from soil, including Solidification/Stabilization (S/S), soil washing, electrokinetic remediation, and chemical oxidation/reduction, the negative environmental, social, and economic effects of these traditional methods limit their overall sustainability. The fields of phytoremediation and phytomining, which involve the use of plants to remove organic and inorganic contaminants from contaminated soil, are expanding quickly. Due to its low cost, little impact, and greater public acceptance, this solar-power driven, green technology is frequently preferred over more traditional techniques of clean-up. Thorough consideration must be given to the long-term effects of green plant technologies in eliminating or sequestering environmental contaminations. This chapter critically examines these eco sustainable restoration techniques and green technologies for soil remediation as well as the cutting-edge soil amendments they employ.

Plants and associated microorganisms have shown efficient uptake, sequestration and detoxification of heavy metals (HMs) and organic pollutants (OPs) and have been constantly engineered to be used in phytoremediation or biomining as a green, economical and sustainable solution in soil, water and sediments. In this chapter, we introduce the major progress to improve phytoremediation techniques through biotechnology, as well as biomining. First, a detailed description underlying conventional remediation techniques and plant mechanisms for tolerance is provided. Then, the potential phytoaccumulator plant species associated with native or exotic microorganisms are cited, and we provide a critical analysis regarding the ability of the rhizospheric environment to maintain the services, quantity, diversity and functions in plant‒soil ecosystems. Finally, a meta-analysis based on the Scopus database will be introduced, demonstrating the increased relevance of the topic in the current global scenario. This chapter demonstrates the encouraging results and consequently focuses on a multidisciplinary research aspect.

Pharmaceutical and personal care products (PPCPs) consist of a range of organic compounds, such as Active Pharmaceutical Ingredients (APIs), antimicrobials, hormones, fragrances, and sunscreens, which have sparked tremendous environmental concerns in recent years. The continuous usage, distribution, and accumulation of such bioactive compounds magnify the adverse physiological and health issues across diverse trophic levels, starting from a point source (sewage treatment plants, sludge, effluent release point) towards remote areas. Usage of polluted water for irrigation purposes, microbial sludge and animal wastes as manures and dumping in landfills further alters the soil's physiochemical properties, significantly impacting global biogeochemical cycling. Several physical, biological, and chemical strategies have been widely investigated for eliminating PPCPs in different environments. The lack of adequate and sustainable treatment strategies waits to implement eco-friendly and promising techniques like microbial-assisted degradation (bioremediation) processes. Understanding the process influencing parameters (like microbial metabolisms, activity, dynamics of the native microbial communities, and its capacity for genetic alteration, presence of various enzymes, and diverse degradation pathways) plays a crucial role in assessing the process and removal efficiency. Several cutting-edge methods, including omics technologies (metagenomics, metatranscriptomics, metaproteomic, and metabolomics), have recently been successfully applied to characterise and enhance such metabolic machinery and efficiencies via discovering and identifying distinct microbial genes and proteins that are participating in the degradation process. This chapter address and consolidate such advanced molecular approaches for an exhaustive understanding and industrial application of bacterial-based bioremediation of PPCP, with critical insights through omics technologies. Such technological improvements will significantly benefit society by providing new understandings of mechanisms involved at various biomolecular levels to combat the rising environmental concerns.

The technology behind the plant/microbe induced soil remediation remains one of the best technologies for the treatment of polluted soils. Plants and microorganisms interact with each other and the interaction can be beneficial in terms of environmental sustainability. Microbial and plant-assisted bioremediation enhances the efficacy of soil bioremediation. This phyto-assisted bioremediation (PABR) strategy, relies on the synergistic actions that occur between natural microorganisms and plant root system, this helps in the uptake, detoxification and sequestration of various contaminants from polluted soils. The microbiome of the rhizosphere comprises bacteria, endophytes and AMF (soil-borne fungi) that play crucial roles in plant development and growth. These microorganisms also harbour requisite genes carrying the charge of mineralizing different organic and inorganic compounds via several pathways to produce innocuous by-products. A circumstantial apprehension of the plant–microbe interaction is essential in developing a more efficient remediation technique in achieving greatly improved soil remediation rates.

Soil is the major source that helps in agriculture, farming and regulates the discharge of excess rainwater, thereby preventing flooding. Nowadays by the growing population, many industries have emerged to meet people’s needs. Without a proper waste management system industrial effluents like toxic heavy metals, various types of dyes from the textile industry, and the use of pesticides in crops get accumulated in the soil. Unfortunately, soil is being contaminated as a result of improper industrial waste disposal. This eventually affects the littoral and sub-littoral regions nearby soil. By this aqueous water bodies were becoming contaminated with the harmful chemical substances that harm marine organisms. This can cause diseases and infectious conditions in plants and animals. When this is consumed by humans, it leads to food poisoning, digestive problems, respiratory and heart disease, sometimes in severe cases, even leads to death. As a result, the flora and fauna of the ecosystem were getting affected majorly. Agricultural soil contamination can be treated by soil bioremediation method. Soil bioremediation is the process that reduces the toxicity of heavy metals contaminated in soil and improves the quality of the soil. However, bioremediation itself is a sustainable approach to treating contaminated soil. Bioremediation is considered safe, sustainable, and cost-effective. In this chapter, we have performed a brief literature survey based on biological methods for the removal of organic waste by reducing its toxicity from agricultural soil with an understanding of the bioremediation of soil contaminants using microorganisms.

Many techniques of soil remediation are available but the use of enzyme technology and microbial bioprocesses is eco-friendly and cost effective due to the less energy input requirements. Enzymes especially the oxidoreductases are highly valuable for the removal/degradation of toxic contaminants (polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCBs)) from the soil. Understanding about the mode of action of various biocatalysts and their optimum conditions are well documented, but still their full implementation at a commercial scale is awaited due to their less open environmental stability and cost intensive continuous accessibility. Persistent pollutants from the soil should be eliminated through applying the potent active bio-enzymes that is possible through in situ or ex sit strategies. In this chapter, authors critically focused on the various biocatalysts that are helpful for the bioremediation of polluted soil.

Due to the excessive release of toxic and hazardous compounds into the environment, environmental pollution is increasing day by day. This rapid increase in pollutants results from industrialization and urbanization expansion. This pollutant affects in a harmful way to all the living forms, alters the environmental conditions and ecology, and changes diversity manner. The removal of these pollutants has been attempted using numerous conventional approaches, but they have not proven very successful. Until now microbial bioremediation represents the safest way to turn pollutants into non-hazardous materials. Soil ecosystem contains diverse microorganisms with a large capacity of removing a large number of pollutants through their unique enzymatic power. Microbial enzymes are proven to be an efficient and environmentally friendly technology solution for detoxifying pollutants from the environment. Many soil organic pollutants can be remedied by enzymes, including organo-heavy metals, PAHs, azo dyes, and polymers. Hydrolase enzymes (esterase, protease, lipase, cellulase, cutinase), and organophosphorus hydrolase enzymes (oxygenase, peroxidase, laccase) are the main pollutant-remediating soil enzymes. The current state of soil pollution, harmful pollutants’ impacts on soil life forms, as well as the microbial bioremediation enzymes, types, mechanisms, and possible applications, will be discussed in this chapter.

Plants are the natural source of bioactive compounds used in medicinal and environmental sectors as well as being widely used in commercial and pharmaceutical products. Bioactive plant metabolites are the secondary metabolites produced by plants with the purpose of making them competitive in natural environment. Plant secondary metabolites elicit pharmacological or toxicological effects in man and animals. Besides producing the primary biosynthetic and metabolic compounds associated with plant growth and development, secondary metabolites are produced within the plants and are regarded as the products of biochemical ‘side tracks’ in the plant cells. Several of the bioactive metabolites have contributed various types of important functions in living plants such as providing defence against herbivores, protection against infections, attraction or signalling. Bioactive metabolites also play a role in the complex biological and ecological processes that occur in the rhizosphere through ecosystem-level interactions between plant roots and the soil fauna. Various studies have revealed that bioactive molecular exchanges mediate these interactions as intercellular signal and helps the partner in preparing for various successful interactions. This review article provides a comprehensive analysis of the major bioactive molecules produced by plants, their role in below-ground ecosystem, in remediating the soil ecosystem methodological challenges and novel avenues for their study.

Soil bioremediation is a process of using microorganisms to clean-up contaminated soil, while soil stabilization is an approach to adding materials to the soil to improve its physical properties and stability. In recent past, utilization of microbial enzymes appears to be one of the alternative and effective approaches in biodegradation for various complex and toxic environmental contaminants. Bio-enzymes seem to be involved in various aspects of soil bioremediation and plant–microbe interactions suggesting understanding the role of bio-Enzymes in soil ecosystems can help in designing more effective strategies for the removal of the contaminants from the environments. In this Chapter, we summarize the current knowledge on the biotransformations of toxic pollutants using novel omics approaches. This chapter presents an extensive exploration of bio-enzymes, unveiling their complexities and showcasing their tremendous potential in biocatalysis and diverse industries. This chapter, we will also focus on the current state of the art of biodegraded and toxic pollutants, focusing on the use of novel omics approaches (genomics, transcriptomics, proteomics, metabolomics, and fluxomics) as tools to study the molecular mechanisms behind the transformations of the toxic pollutants. By studying bio-enzymes, scientists can access their powerful capacities to promote healthcare and bioremediation, among several other fields.

Harmful unused resources, carbon-based impurities, pesticides and heavyweight metals cause environmental pollution which has unfavourably affected the ordinary soil system. Soil quality is diminishing day by day and creating an adversative effect on humanoid, nourishment and atmosphere. Therefore, soil well-being repair is the necessity of society. Plants and microorganisms perform a dynamic part to restoration of soil health and quality by diminishing all kinds of impurities. Bioremediation is progressively a standard exercise aimed at the refurbishment of soil grade, after all the process stands much environmentally-safe, rate operative contrast with respect to ordinary physio-chemical approaches, that remain quite costly besides unsuccessful. This chapter offers a summary on approach of bio-engineered plants, microbes towards refurbishment of soil grade via deterioration of numerous impurities. This book chapter will also discuss various techniques utilized via microorganisms and plants for soil restoration. This will again highlight the consequence of refining the capacity of microbial enzymes to efficiently destroy heavyweight metals at sufficient degree, underlining current developments in microbes’ soil bio-remediation and phyto-remediation for the same in addition to upcoming scenarios and limits.

Bioremediation is a promising approach for managing environmental contamination caused by various pollutants. However, traditional bioremediation techniques may not always be effective due to factors such as low microbial activity, slow degradation rates, and poor accessibility to contaminants. Therefore, the integration of nanotechnology in bioremediation has the potential to achieve both efficacy and sustainability in remediation efforts. Nano-materials can improve the adsorption and transportation of contaminants, increase microbial activity, and enable targeted delivery of bioremediation agents. The utilization of metal-based nano-materials, biogenic nano-particles, carbon-based, polymer-based, enzyme-based nano-particles, and various nanosensors has become crucial technology for bioremediation. This chapter discusses different types of nano-particles, their applications, and the detailed mechanisms of the bioremediation process. Hence, nano-materials can be used for bioremediation to eliminate toxic contaminants, resulting in reduced time consumption and costs, making it an advantageous solution. Additional study is needed to evaluate the potential environmental concerns associated with using nano-materials and to perceive their mechanisms in bioremediation.

Soil has a multiple role in maintaining the ecological balance of the earth. A good quality soil subsidizes to the growth and development of plants, dietary supplements for human nutrition and regulates the level of water and air. It has become a high global challenge because of rapid anthropological activity to retain the soil fertility and revitalize quality. Some of the major pollutants include heavy metals, pesticides as well as persistent organic pollutants. The plant-based soil bioremediation is a promising technique to eliminate contaminants and prevent the build-up of contaminants. Also, biomass accumulation on plants grown from contaminated soil can be subjected to the production of biofuels by pyrolysis, gasification, hydrothermal liquefaction and microbial electrolysis cell. Furthermore, the improvements in soil bioremediation and biofuel production can be achieved by excellent nano-materials with the help of their high specific area and high reactivity that makes them easier to deliver into soils. This chapter details about the plant assisted soil bioremediation, some of the biologically produced nano-materials and their role as effective enhancers in bioenergy production.

Soil bioremediation is the essential solution to the soil pollution that is affecting the human health, ecosystem and biodiversity. The conventional methods used so far to address this problem can only remove the contaminants but are not effective in complete destruction of the hazardous contaminants. Moreover, the conventional procedures are laborious, expensive and time consuming. Recent advances in genetic engineering have evolved alternative, environment friendly and cost-effective methods of soil bioremediation. Oil spills, xenobiotics, heavy metals, non-degradable plastic pollutants, toluene, trichloroethylene, xylenes, naphthalene etc. are the main soil pollutants. The genetically engineered microbes and transgenic plants can either mobilize or degrade these contaminants and are found to be useful in decontamination of polluted land sites. Genetically engineered plants and microbes can together in a symbiotic manner be useful in bioremediation of contaminated soil. This chapter includes the most utilized bioengineering approaches like mega nucleases, Transcription Activators-Like Effector Nucleases (TALENS), Zinc Finger Nucleases (ZFN) and Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas associated nucleases to improve the biological mechanism of plants and microbes that are useful in soil bioremediation.

Green technologies to clean up contaminated soil for sustainable development. Green technologies can be used to remove contaminated soil from the environment. The technology can be applied to clean water and soil in a variety of ways to reduce the risk of water pollution. The remediation of contaminated soil is a major challenge in the sustainable development. The green technology has been developed to solve this problem by using plants and microorganisms. This chapter reviews the current status of green technology for remediation of contaminated soil, including phytoremediation, bio stimulation, bio augmentation and bio mining. The main objective is to develop a method that can be used in developing countries where there are many contaminated soils and limited resources available for clean-up. The proposed methodology is based on the concept of using green technologies as a means of cleaning up contaminated soils, rather than relying on traditional methods such as physical removal and chemical treatment. The Re Soil soil-washing method effectively removes hazardous metals, maintains the condition of the soil, and creates emissions or liquid wastes. This approach has been developed by taking into account key factors such as cost effectiveness no, environmental impact, sustainability and applicability in different areas around the world. Further research on these technologies is needed to develop effective and efficient methods for cleaning of polluted sites with minimal environmental impact.

Environmentally friendly soil remediation techniques are now more crucial than ever. Utilizing natural mechanisms to degrade organic pollutants or gather and stabilize metal pollutants is one promising strategy. This book chapter examines the area of soil remediation as a green technology, with a focus on the function of advantageous bacteria and fungi as microorganisms that promote plant growth. These microorganisms have the potential to both directly and indirectly alleviate metal phytotoxicity while boosting plant growth. The chapter addresses the mechanisms, difficulties, and future perspectives for remediating metal(loid)-polluted agricultural soils and looks into biotechnological remediation methods, such as phytoremediation and microbial remediation. Additionally emphasized are recent advancements and future directions for microbial and phytoremediation of toxic contaminants, focusing on the significance of plant and cooperative microbial interactions in metalliferous environment adaptation and enhancing overall soil remediation. In general, this chapter offers insightful information about the possibility of environmentally friendly soil remediation techniques for reducing the effects of harmful pollutants on agricultural soils.