Preface Fast growing human civilization, industrialization, mineral mining, oil exploration, modern agricultural practices and related anthropogenic activities in the world have resulted in elevated levels of toxic heavy metals and xenobiotic pollutants such as pesticides, petroleum hydrocarbons, electronic wastes, etc. in the environment. These pollutants impose hazardous impacts on living organisms, ecosystem health and also human health. Therefore remediation of these contaminants is becoming one of the serious environmental issues in the world. Clean up of the polluted sites can be done by physic-chemical methods which have several disadvantages such as high energy and labour requirement, generation of secondary wastes and very high cost. Recent researches have been oriented to utilize soil microorganisms either alone or together with plants to remediate and improve disturbed ecosystems. This approach is eco-friendly and relatively less expensive compared to physico-chemical methods. The investigations carried out using microbes for restoration of degraded eco-systems is limited. The proposed book covers this aspect.  The book is organized into 15 chapters. All the chapters have been contributed by renowned scientists; 13 chapters by Indian scientists, 1 chapter by Indonesian scientists, and 1 chapter by Canadian scientists. Chapter 1 deals with reclamation of saline soils of Tamil Nadu by microorganisms. Chapter 2 helps to understand the significance of microbes for synthesis of humification processes.  Chapter 3 deals with biosorption of heavy metals by microbes and agrowastes. Chapter 4 is devoted to the role of mycorrhizal fungi influencing plant diversity and production in an ecosystem. Chapters 5 to 7 provide up-to-date information on biological recovery of heavy metals by microorganisms in general and mycorrhizal fungi in particular. Chapter 8 deals with microbial degradation of textile-dye wastes. Chapters 9 and 10 respectively cover the role of microbes in the remediation of environments contaminated with toxic pollutants and pesticides. Chapters 11 to 13 are devoted to bioremediation of mined-out ecosystems. Chapter 14 discusses the role of mycorrhizal fungi in the restoration of coastal sand dune and mangrove forests. Chapter 15 discusses the biological degradation of crude oil contaminants.

Abstract The functioning and stability of terrestrial ecosystem are determined by plant biodiversity and species composition. So far, little attention has been paid to the effects of microbe-plant interactions, particularly the mycorrhizal symbiosis, on ecosystem variability, productivity and plant biodiversity. The most common type of mycorrhizal association is the arbuscular mycorrhizal (AM) type. The role of AM fungi in the uptake of diffusion limited nutrients like P and in conferring resistance to soil-borne-diseases is well documented.

Abstract Study was undertaken to investigate the toxicity of heavy metals on the structure and function of ectomycorrhizal fungi and their ability to colonize the pine seedlings. Ectomycorrhizal fungi were isolated, cultured and multiplied on MMN medium. Six heavy metals (Cd, Ni, Zn, Pb, Cu and Al) were selected and different concentrations viz; 0 ppm (control), 10 ppm, 50 ppm, 100 ppm, 200 ppm and 500 ppm were used for treating the seedlings. The study was continued for one year. Different growth parameters were measured. Factors such as soil moisture, pH and soil organic carbon on ectomycorrhizal colonization were also analyzed. The mycorrhizal colonization was more in those seedlings having lower concentration of heavy metal treatment. Statistical data analysis has shown that the heavy metals had negative correlation with mycorrhizal colonization. High concentration of metals were toxic to external mycelium, which ultimately resulted in reduction of ectomycorrhizal development. The accumulation of metals in the fungal mycelium and protecting root against metal toxicity was an important factor.

Abstract Contamination of environment with heavy metals has become a serious global problem due to its threat to animal and human health. Removal of this non-biodegradable, hazardous heavy metals through bio-materials has received paramount interest and intense attention in the last few decades as bio-materials play crucial role in remediating heavy metal polluted environment through a process called “biosorption”. The term biosorption, therefore, has become a popular theme in recent years due to its relatively simple, inexpensive, eco-friendly with rapid mechanism of removing heavy metals from polluted environment. There have been burgeoning studies around the globe for alleviating the problem of heavy metal pollution by selecting and developing an effective bio-sorbent with minimum treatment process for field application. This review aims to provide vast information on types of biosorbent available, their exploitation for better efficiency and their economic attractiveness for the restoration of heavy metal polluted environment.

Abstract Contamination groundwater and soil due to heavy metals (HMs) has aggravated into a threat not only for people inhabiting the polluted areas but also for the vegetation of the region. Relying on the use of obligate symbionts, arbuscular mycorrhizal fungi (AMF) in remediation of contaminated sites can be a productive approach. These fungi due to high cation exchange capacity have the ability to adsorb heavy metals (HMs) on fungal tissues; they also possess enzymes responsible for reduction of metals to less toxic forms. In areas with high toxicity of various HMs such as lead, AMF extends its extraradical mycelium (ERM) beyond the depletion zone of plant roots increasing the availability of nutrients such as potassium, phosphorus, magnesium, and sulphur resulting in increased plant growth and yield. Production of phenol and organic acids by the fungus have been reported to increase iron diffusion, that is a co-factor for antioxidant enzyme superoxide dismutase. AMF sequester HMs in fungal structures and bind them in their chitin cell walls preventing their translocation to aerial plant parts.

Abstract Excessive use and treatment of soil with pesticides under the adage, “if little is good, a lot more will be better” has played havoc with human and other life forms and can also cause populations of beneficial soil microorganisms to decline, which indirectly affect soil fertility. Soil constitutes a major environmental sink for many pesticides. These pesticides are either taken up from soil by plants and then pass into the bodies of invertebrates, water or air, directly or indirectly and affect public health and beneficial biota of the ecosystem. Bioremediation provides very attractive, eco-friendly and economic solution to many of our hazardous pollution problems. For both economic and ecological reasons, biological degradation has become an increasingly popular alternative for treatment of hazardous wastes.

Abstract   Within the time scale for soil formation, humans appeared to the planet within the last 1 million years. They shifted their lifestyle from hunter-gatherer to nomadic animal husbandry and finally to cultivation of domesticated crops only within the last 10,000 yrs. Earlier, these crops were cultured in a semi-nomadic style as land was plentiful, so when soil lost its productivity, people abandoned it in favor of new-land. Gradually, as land became scarcer and population exploded, agriculture evolved to continuous cropping of the same parcel of land. This discovered the major concern for soil health. As organic matter is key to soil health, humus is the last stage of organic matter decomposition. Humus is a complex aggregate of dark brown colored amorphous substances, which have originated during the decomposition of plant and animal residues by microorganisms, under aerobic and anaerobic conditions. Humus and living microorganisms are connected by numerous ways which must be appreciated in order to understand the origin and nature of humus. Our attempt is to narrate the role of organic matter and vital role of microbes in humification process.

Abstract Electronic waste or e-waste is one of the emerging problems in developed and developing countries worldwide. The constantly changing today’s world of technology has led to the serious problem of e-waste. The previous studies show that India has generated 0.6 million tons of e-waste in 2014 which may increase to 0.7 to 0.9 million tons by 2015–2016. E-waste constitutes multiple components some of which are toxic that can cause serious health and environmental issues if not handled properly. The challenge is to develop innovative and cost-effective solutions to decontaminate polluted environments, to make them safe for human habitation and consumption, and to protect the functioning of the ecosystems which support life. Biological approach is currently applied to recovery of metals from contaminated soil, groundwater, surface water, and sediments including air.

Abstract Now a days, the public has become more sensitive towards the protection of the environment and general awareness has increased about the adverse effects of industrial effluents contaminate with various pollutants, including dyes on the environment. Dyes are an important class of synthetic organic compounds used in many industries, especially textiles. Consequently, they have become common industrial environmental pollutants during their synthesis and later during fiber dyeing. Textile industries are facing a challenge in the field of quality and productivity due to the globalization of the world market. The dyes, which are widely used in textile industries when left in water bodies without any treatment cause environmental pollution and in turn are toxic, carcinogenic and mutagenic. The efficient treatment of the sludge from the industries is not economical and a challenging task. Currently, a number of different technologies and methods such as biological, physical and chemical are widely used for the removal of dyes. The treatment technologies for the removal of textile dyes from the textile wastewater found that over the past two decades interestingly focused on biodegradation methods such as microbial decolourization, enzymatic decolourization, adsorption by microbial biomass (living or dead) and bioremediation systems as a better alternative as the available physico-chemical methods.

Abstract With recent advances in molecular biology and rapid developments in new analytical techniques, engineering of microbes for the bioremediation processes has been extensively studied as recombinant microbes can degrade various toxic pollutants effectively. The prospect of microbial engineering has greater potentialities for agriculture and environmental applications and this may provide us deeper insight in understanding the microbial interactions and biotransformation processes. Though much work has been carried out on bioremediation using genetically engineered microorganisms, its application is restricted to environment due to the concerns of health and environment over ecosystem. Nevertheless, evaluation of risk assessment has also been carried out in order to ascertain the potential benefits of transgenic microbes.

Abstract Traditional practices of restoring and vegetating mine spoils, which include mechanical tillage, the addition of tons of organic and mineral inputs, seeding of herbaceous plants, and regular fertilization, are often expensive and not sustainable on the long term in the Canadian boreal forest biome. Phytobial restoration and remediation may be an excellent alternative to these traditional practices while accelerating ecosystem reconstruction and sustainable reforestation of mined sites. In this review, the role and importance of root symbionts – ectomycorrhizal fungi, PGPR, and Frankia – on boreal tree fitness are discussed. Furthermore, highlights of recent research studies done by our team in Canada on ecological restoration and bioremediation of boreal mined sites are presented.

Abstract   Opencast mining destroys the original land ecosystem and microbial community due to mining and stockpiling of mine rejects on adjoining land, which is a matter of great environmental concern. Mining creates formation of wastelands, formation of gullies, ravines, overburdens, reduced water infiltration and increased runoff. Reclamation of mined out areas is often difficult due to its chemical, physical and biological traits. Absence of topsoil is the most common feature of the mine spoils dumps. Arbuscular mycorrhizal fungi (AMF), the synonym of VAM fungi, are important microbes of soil that form symbiotic association with most of the terrestrial plants on the earth. Observations led to use of legume microsymbionts as biological substitutes for fertilizers. AMF diversity increases with species diversity of plants as the potential number of association increases. Dominant arbuscular mycorrhizal fungi can prevent the invasion of non-mycorrhizal plants on land where they have established symbiosis and promote their mycorrhizal host.

Abstract Mine spoils pose adverse conditions for soil microbes and plant growth, due to its low organic content and other essential nutrients, unfavourable soil chemistry and poor soil texture. Poor microbial population inhibits nutrient transformation, consequently the establishment of the plants and ultimately affects the process of ecological succession. A synergy among different groups of beneficial microbes accompanied by plantation of suitable tree species on mined over area has proved to be effective for speedy and efficient revitalization of the mined affected lands. Inoculation of plantation with efficient strains of native microbes accelerates the soil redevelopment and helps to establish nutrients cycle readily which attracts native flora thereby the pace of natural regeneration is increased. It is therefore imperative to consider the application of effective microflora in restoration of mined lands along with the plantation.

Abstract Alleviating plant salt stress and remediating saline soils are of great economic interest. Beneficial microbes such as arbuscular mycorrhizal (AM) fungi, plant growth promoting rhizobacteria (PGPR), etc. are associated with many plant species including trees. These beneficial microbes can cope up with salinity and help the plants to survive in such soils. Diversity status of beneficial microbes from the samples collected from different salt affected areas was investigated by many researchers. They screened and identified the efficient PGPR isolates isolated from saline areas for plant growth hormone (IAA) production and phosphate solubilization. The significance and highlights of the recent research as well as the past understanding of beneficial microbes and their role in reclamation of saline areas is discussed in this paper.

Abstract Sustainable landscape and forest management are of utmost concern in alleviating climate change. Fungal mutualism is one of the most significant positive biotic interactions responsible for forest structure and longevity. Coastal sand dunes imitate xeric habitats, while mangroves and river floodplains are often marshy. In spite of such extremities, mycorrhizal fungi are prominent component in coastal vegetation. Studies so far revealed that mycorrhizal association in herbaceous plant species is responsible for dune formation, stabilization and serve as potential inoculum in coastal habitats. Mycorrhizal association facilitates plant species to exploit larger volume of soil, supply nutrients (organic nitrogen, phosphorus and minerals), aggregates soil, provides tolerance to salinity stress, relieves from water stress and protects roots from pathogens. Human interference has severe impacts on plant-mycorrhizal mutualism in coastal habitats. Cultivation of exotic tree species and their uncontrolled exploitation further impoverish the habitats. Protection of native herbaceous flora, cultivation of native tree species and introduction of selected indigenous keystone species in disturbed habitats with mycorrhizal mutualism is an appropriate measure of rehabilitation.

Abstract Since the first oil well drilled successfully in 1859, crude oil has been a serious problem around world, including Indonesia. As a source of all petroleum products, crude oil is very complex component and divided into aliphatic, aromatic, resin and asphaltene. Petroleum products have been used for daily life and created large amounts of pollutants in environment and ecosystems around the globe. The pollutants should be treated by certain method; among them, bioremediation has several advantages to resolve the problem. In 2003, Ministry of Environmental (MoE) – Republic Indonesia was endorsed with a new regulation about biological treatment or bioremediation for crude oil contaminated soil (MoE regulation No. 128/2003). The most important to be noted in bioremediation process is the presence of microbes with certain metabolite capabilities. The degradation rate also can be improved and sustained by ensuring the adequate required factors. This article describes the removal of crude oil by utilization of microbial potentials, factors affecting biodegradation, and how they are applied in Indonesia.