Search

Today food and various food supplements of fungal origin are consumed all over the world in vast quantities, and its commercial production is part of a rapidly growing industry. Fungi are of excellent value nutritionally and of great importance whether as a direct food source, as a medicine or as a processed food. Edible mushrooms are easily cultivable and are excellent sources of protein, have low-fat content and are free of cholesterol. They are consumed either in fresh or processed form. To combat the problem of food shortage, single cell proteins were produced using yeast cells which are protein extracts with high amino acid content potentially favourable for use in human nutrition. Similarly, mycoprotein marketed as Quorn™ is now available in supermarkets, as a high-protein, low-fat, cholesterol-free ‘meat alternative’. In this book chapter various commercial applications of fungi have been discussed for the production of nutritionally important food products and food supplements.

Generation of wastewater is unavoidable but its discharge into the environment is of great concern. Wastewater treatment process is designed in a manner to allow the process of natural breakdown of pollutants in controlled conditions. The physical and chemical processes include removal of solids materials. The one method which all wastewater treatment processes have in common is the biological method. This process relies on the use of some microorganisms to convert organic contaminants into environmentally beneficial product. A wastewater treatment plant itself is a microbial zoo containing bacteria, protozoa, metazoa, and various micro life. During the course of their processing in wastewater treatment plant, the amount and share of the microbial community in wastewater will continue to change. The type of technology used for wastewater treatment significantly affects the microbial content of treated wastewater.

In recent times, with the help of nanotechnology, it has been possible to tailor and fabricate the structures of large materials at extremely small scales to achieve specific properties, quite different from either their fine particles or bulk counterparts. Nanoparticles have profound applications in medicine in nanosensors, cell imaging, drug delivery, environmental remediation, etc. Although they have been successfully synthesized using different physical and chemical methods, their obvious disadvantages have led the researchers to focus more on the synthesis of bionanoparticles. Fungal systems have attracted much attention in this regard, as they are ecofriendly, biodegradable, easy to culture and scale up, with a high wall binding capacity. Moreover they have quite high metal bioaccumulation capacity and are effective secretors of extra- and intracellular enzymes which help in the formation of different metal nanoparticles. The mechanism of synthesis, characterization, and applications of mycogenic nanoparticles make this a fairly new and exciting area of research with considerable potential for further development.

Pollution of water by heavy metals has become a matter of serious concern. Reclamation of heavy-metal-polluted water is quite challenging, as the metals are nonbiodegradable in nature and persistent in the environment. Heavy metals such as arsenic (As), chromium (Cr), mercury (Hg), cadmium (Cd), lead (Pb), and copper (Cu) when present in the water at a concentration above the permissible limit can have severe deleterious effects on both plants and animals. They are cytotoxic at a very low concentration and can cause several life-threatening diseases in humans. Conventional techniques for their removal include chemical precipitation, chelation, oxidation-reduction, ion-exchange, etc. These methods are costly and produce toxic sludge as secondary pollutant. Bioremediation has thus emerged as an attractive, economical, and eco-friendly alternative. The role of different microbes such as bacteria and algae in the remediation of heavy metal pollution is currently being enormously investigated. These microbes have shown great adaptability with respect to tolerance and survival in the presence of elevated concentrations of these metals. Bacterial and algal biomasses act as potential biosorbents that can be effectively applied as a part of sustainable treatment for the reclamation of heavy-metal-contaminated water in different wastewater treatment plants.

There has been a sharp increase in the world’s population over the past few decades which can be threatening in terms of the food security of the people. Thus, to cater to the huge demand of food, agricultural production should be increased within a short span of time and with limited worldwide agricultural land resources. This situation has driven the farmers all over the world to rely heavily on the commercially available chemical fertilizers for enhanced agricultural productivity. Though there has been a significant rise in the production of crops, these fertilizers have proved to be detrimental for our ecosystem as well as animal and human health. The deteriorative effects of the large chemical inputs in the agricultural systems have not only challenged the sustainability of crop production but also the maintenance of the environment quality. Using biofertilizers is a natural, low-cost, environment-friendly way out to this problem. Biofertilizers comprise living microorganisms capable of supplying sufficient nutrients to the plants, while maintaining high yield. The present chapter aims at describing in brief the requirement of biofertilizers in the first place, as well as their choice over the conventional synthetic ones, the different types, their roles in agriculture, their production and mode of action and most importantly advantages and demerits. The inputs from various literature mentioned herein will help in understanding the immense importance of their usage in modern-day farming with a cleaner ecosystem.

One of the major crises that the world is facing today is environmental pollution. Synthetic dyestuffs find uses in various industries like textile, cosmetics, leather, paper printing, tannery, food coloring, etc. Recalcitrant azo dyes (-N=N-) are the predominant class of molecules used because of their color fastness, persistence in aquatic environment, stability, and resistance to degradation. These detrimental compounds are quite complex and structurally diverse, containing azoic linkages. It is evident from prior researches that these dyes and their by-products, specifically the aromatic amines, which result due to the reductive cleavage of the azo bonds, are classified as extremely toxic, carcinogenic, mutagenic, and genotoxic to humans and aquatic biota and are also capable of causing serious skin irritations. They inhibit aquatic photosynthesis by obstructing light penetration, deplete dissolved oxygen (DO) level, and compromise both aesthetics and ecological balance of water bodies. Dye-laden wastewater from industries is often released into the environment, untreated or poorly treated, to avoid the complexity and investment of capital for setting up of treatment plants, thus absolutely defying the environmental standards. The developing and underdeveloped countries are exposed to a bigger risk as they are being exploited as lucrative spots for the development of production sites by the textile industries to lower the production costs. The existing processes for color removal consist of physical, chemical, and physicochemical ones, the recent addition to the list being the biological means. Though the accepted techniques are quite capable, yielding satisfactory results, each of them has their fair shares of advantages and disadvantages. Till now, a single, universal method, capable of complete degradation of these dyestuffs and being economically feasible at the same time, is far out of reach. While the various physicochemical methods are established industrially, they often generate huge amount of sludge as secondary pollutants, apart from being cost and energy intensive. Thus, focus has been shifted toward the exploitation of the capability of the vast array of biological entities for remediation of these toxic compounds. Biological means, though cheap and are able to completely mineralize the dyes, are often restricted to the lab scale. In search of effective treatment procedures, researchers are targeting the already existing methods and combining them for the development of potential hybrid technologies.