eChapters

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

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

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

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
 
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

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

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

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

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

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.

Thiamann (1948) designated the plant hormones by the term ‘phytohormones’ in order to distinguish them from animal hormones. He defined a phytohormone as “an organic compound produced naturally in higher plants, controlling growth or other phy-siological functions at a site remote from its place of production and active in minute amounts.”

According to Johannes van Over-beek (1950), the plant hormones are defined as “organic compounds which regulate plant physiological process – regardless of whether these compounds are naturally occurring and/or synthetic; simulating and/or inhibitory; local activators or substances which act at a distance from the place where they are formed.”

An anti-nutritional factor is a substance which, when present in human or animal foods, reduces growth. Examples are phytate, protease inhibitors (notably soybean trypsin inhibitor) and excessive dietary fiber.

Anti-Nutritional Factors

    ·    Protease inhibitors inhibit the activity of trypsin, chemotropism and other proteases. They are found in legumes such as beans and peas, but also in cereals, potatoes, and other products. Their presence results in impaired growth and poor food utilization.

Phenolics are broadly distributed in the plant kingdom and are the most abundant secondary metabolites of plants. Plant polyphenols have drawn increasing attention due to their potent antioxidant properties and their marked effects in the prevention of various oxidative stress associated diseases such as cancer. Polyphenols are a structural class of mainly natural, but also synthetic, and semisynthetic, organic chemicals characterized by the presence of large multiples of phenol structural units. The number and characteristics of these phenol structural underlie the unique physical, chemical, and biological (metabolic, toxic, therapeutic, etc.) properties of particular members of the class. The term polyphenol derives from poly-, from the ancient Greek word (polus, meaning “many, much”) and the word phenol which refers to a chemical structure/substructure formed by attaching to an aromatic phenyl or benzenoid ring an alcohol-type hydroxyl (-OH) group (giving rise to the “-ol” suffix). The term “polyphenol” has been in use since 1894.

The pigments are energy-rich organic compounds. The potential chemical energy of these compounds comes from the light energy. The light enrgy to be effective in photosynthesis must be absorbed by a suitable pigment. This vital role is performed by a suitable pigment. This vital role is performed by the green pigment. Chlorophyll, carotenoid (carotenes and xanthophylls), anthocynin and phycibilins.

Franz Holfmeister’s (LT, 1850-1922) definition, “vitamins are substances which are indispensable for the growth and maintenance of the animal organism, which occur both in animal and plants and are present in only small amounts in food”, still holds good, although it has been interpreted in various ways.

The term enzyme was coined in 1878 by Friedrich Wilhelm Kuhne to designate these biological catalysts that had previou-sly been called ferments. As they quicken most of the chemical reactions occurr-ing in the body, the enzymes have been designated as the “manifestations of nature’s impatience”.

Nucleic acids like proteins occur in all living cells. They device their name because of their primary occurrence in the nucleus and acidic nature. Deoxyribose nucleic acid (DNA), one of the two nucleic acids is a major component of chromosomes. Small amounts of DNA are also found associated with chloroplasts and mitochondria.

Lipids are a hetrogenous group of substances, widely distributed throughout the plant and animal kingdom. In plants they are present in the seeds nuts and fruits, while in the animals they are stored in adipose tissues, bone marrow and nervous tissues. Lipids are relatively insoluble in water and readily soluble in organic solvents such as ether, chloroform, carbon disulfide, benzene, hot alcohol etc. The term lipid was used by the German biochemist Bloor in 1943 for a major class of tissue components and foodstuffs.

Amino acids are essential components of all living cells as building blocks of proteins. They are also metabolically active and supply substrates for many other biochemical reactions. In a bacterial cell, about 0.4% of the dry weight is amino acids. The amino units in other living systems varies according to species, age and part of the body.

Carbohydrates are synthesized from CO₂ and H₂O in chlorophyll containing plants during photosynthesis. The term carbohydrate was originally coined for this class of compounds as most of them were hydrates of carbon or could be represented by the general formula C_n(H₂O)n. Not all the carbohydrates however, have this empirical formula, for example deoxyribose (C₅H₁₀O₄) and glucosamine (C₆H₁₃O₅N). Further lactic acid (C₃H₆O₃) formaldehyde (HCHO or CH₂O) and acetic acid (CH₃­.COOH or C₂H₄O₂) with this general formula is not a carbohydrate. Carbohydrates are defined as the compounds having either an aldehyde or a ketone group or a modified aldehyde or ketone group and other carbon atoms with alcoholic (-OH) group. Hence the continued usage of the term carbohydrate is for convenience rather than exactness.