Metals naturally exist in the crust of the earth, and their compositions vary among different localities, resulting in structural disparity of surrounding concentrations. Some heavy metals are much important in trace amounts in respect to living organisms related to their metabolic activities. High solubility of various heavy metals changes them into extremely toxic and perilous contaminant of water and soil when discharged by many industrial activities. When these metals are released into the environment, they can be leached into the underground waters, depositing in the aquifers, or run off into surface waters and soils thereby resulting in water and soil pollution. Thus, heavy metals become a potential contaminant for environment that can partake in trophic transfer in food chains. The toxicity of heavy metals mainly depends upon its relative oxidation state, which is responsible for physiological bio-toxic effects. When these metals enter into the living organisms, they, combine with proteins, enzymes, and DNA molecules, form highly stable biotoxic compounds, thus altering their proper functioning and obstructing them from the bioreactions. Arsenic, chromium, cadmium, and lead are highly toxic and produce mutagenic, carcinogenic, and genotoxic effects. Hence, this chapter is focused on occurrence and allocation of heavy metals, their toxicological impact on environment, and their possible eco-friendly remedies for green and healthy environment.

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The silkworm derives nutritional requirement from mulberry leaves for their growth and development, variations on the components of mulberry leaves may have some influence in the growth and development of silkworm. The nutritional parameters of mulberry leaves and silk production are directly proportional to each other. The nutritional composition of mulberry leaves vary depending on the soil and other environmental factors of the locality, moreover the genotypic characteristics. An effort has been made to determine, identify and analyse, the nutritional composition of different varieties of mulberry leaves, namely S-13, S-146, S-1635, S-1, AR-12, AR-14, S-36, S-54, TR-10 and BR-2 mostly found in Lucknow region of Uttar Pradesh, India. The current paper deals with quantification of protein, carbohydrate, total carotenoids, chlorophyll a, chlorophyll b, total chlorophyll contents of different varieties of mulberry grown in this region. The quantitative determination of nutritional composition indicates that BR-2 variety contains significantly higher concentration of protein content (0.308 mg/ml), carotenoids (0.0334 mg/gm), along with S-36 variety containing significantly higher quantity of proteins (0.3029 mg/ml), chlorophyll a (0.0858 mg/gm), chlorophyll b (0.0329 mg/gm), total chlorophyll (0.1034 mg/gm) and total carotenoids (0.0479mg/gm). The carbohydrate content of S-1635 variety (0.4341 mg/ml) was significantly found highest as compared to other varieties. The statistical data analyses showed that all the nutritional parameters are found to have highly significant differences between them ('p'<0.01). Finally S-36 and BR-2 varieties hence are regarded as suitable with consistent performance over many characters.

The aim of this study was to isolate, characterize and identify the bacterial pathogens from treated tannery wastewater and also to study their multi-drug and multi-metal resistance property. Three bacterial strains of pathogen species with more antagonistic activity were identified as Pantoea sp., E. coli sp., and Lysinibacillus spp., with accession nos. KJ576899, KJ576900 and KJ576904, respectively for public domain. The antibiotic and heavy metal resistant property of isolated bacterial strains was investigated by disk diffusion method on Muller-Hinton agar and nutrient agar medium amended with increasing concentrations of various toxic metal ions. The isolated bacterial strains Pantoea sp. was sensitive to amikacin, ampicillin, cefepime, chloramphenicol, levofloxacin, meropenem, nalidixic acid, piperacillin and resistant to for carbenicillin, aztreonam, cefotaxime, ciprofloxacin, cotrimoxazole, moxifloxacin, streptomycin, tetracycline. The other two bacterial strains of pathogen E. coli sp., and Lysinibacillus spp. showed different level of resistance and, sensitivity, to many antibiotic tested. In addition, the bacterial pathogens also showed the Minimum Inhibitory Concentration (MIC) of Cd, Cu, Cr, Co, Ni, Mn, Pb, Zn and Fe. These multi-drug and multi-metal resistant organisms can be used as a potential agent for the bioremediation of metal contaminated sites.

In recent decades, scientists in different disciplines have been increasingly concerned about the fate of natural organic matter, and in particular of humic substances (HS). The term humic substances (HS) incorporates refractory autochthonous and terrestrial organic matter in the soil and aquatic ecosystem, and are one of the key fractions of natural organic matter. These substances are important chelators of trace elements constituting complex class of molecular structures that occur naturally, consisting of aggregation and assembly processes in which biomolecules derived from plant and animal residues are gradually transformed through biotic and abiotic tracts. Since these organic compounds are bound by or linked with soil mineral fractions, they must be physically or chemically separated from the inorganic components by an extraction method before their physico-chemical study. This chapter focuses on the chemo-toxicological, molecular aspects of humic compounds and their derivatives such as humins, fulvic acids, humic acids etc., with their agricultural, biomedical, environmental and biochemical applications. In addition to studying their impact on plant physiology and soil microstructure to expand our understanding about humic compounds.