Smart Bioremediation Technologies

Microbial Enzymes

Pankaj Bhatt

• Publisher: Academic Press
• Year: 2019
• Print ISBN: 9780128183076
• eBook ISBN: 9780128183083
• Topic: Biological Sciences
• Subtopic: Microbiology
• Index: Biological Sciences

Smart Bioremediation Technologies: Microbial Enzymes provides insights into the complex behavior of enzymes and identifies metabolites and their degradation pathways. It will help readers work towards solutions for sustainable medicine and environmental pollution. The book highlights the microbial enzymes that have replaced many plant and animal enzymes, also presenting their applications in varying industries, including pharmaceuticals, genetic engineering, biofuels, diagnostics and therapy. In addition, new methods, including genomics and?metagenomics, are being employed for the discovery of new enzymes from microbes. This book brings all of these topics together, representing the first resource on how to solve problems in bioremediation.

• Provides the most novel approaches in enzyme studies
• Gives insights in real-time enzymology that are correlated with bioremediation
• Serves as a valuable resource on the use of genomes, transcriptomes and proteomes with bioremediation
• Refers to enzymes as diagnostic tools

Chapter 1

Mushroom mycoremediation: kinetics and mechanism

Anupam Barh, Babita Kumari, Shweta Sharma, Sudheer Kumar Annepu, Anil Kumar, Shwet Kamal and Ved Parkash Sharma, ICAR-Directorate of Mushroom Research, Solan, India

Abstract

The accelerated industrial and green revolution aimed at increasing industrial and agricultural productivity has led to the entry of several synthetic organic compounds into the natural ecosystems. When the concentration of these chemicals, their metabolites, or by-products goes beyond permitted limits, remediation becomes necessary to avoid migration of these compounds to more sensitive areas. In the search for cleaner technologies, mushrooms are potent biological organisms which are grown on agrowastes. Mushrooms have the ability to breakdown lignin and cellulose and structurally similar organic pollutants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls, dioxins, pesticides, explosives, dyes, and solvents. Mechanisms such as extracellular oxidation, catabolism by enzymes, reduction, hydrolysis, and conversion into metabolites give an insight into the mycoremediation process. Spent mushroom compost was also reported to have bioremediation properties for various harmful and toxic chemicals. The various enzymes such as laccase, catalase, peroxidase, etc. are suitable for this specific mechanism of degradation.

Keywords

Mushroom mycoremediation; enzyme kinetics; mechanism; pesticides

1.1 Introduction

With the advent of the industrial and agricultural revolutions, human have become increasingly powerful over environmental forces. The ever-growing population rise across the globe has magnified the industrial and agricultural activities to meet human needs. Population growth and incremental production activities have adversely affected the natural ecosystem by overexploitation of its resources. Further, the modern technologies which have accelerated productivity at different levels have also resulted in large-scale entry of heavy metals, synthetic xenobiotics, and several other organic pollutants into the environment. Owing to the lack of waste management strategies and disregard by the industrial sector, these pollutants are accumulating and pose a serious threat to the environment. These pollutants are not only conceived as a threat to the ecosystem but also raise concerns about human health hazards. The scientific fraternity is investing their efforts to discover clean technologies that can counteract these negative environmental impacts. In its way, bioremediation is emerging as a safer and cleaner technology to reverse environmental hazards.

Bioremediation is a process that can degrade various pollutants, organic and inorganic contaminants using microbial organisms such as fungi and bacteria, etc. Bioremediation by microbes can be in situ or augmented by external introduction. Extensive studies conducted on edible mushrooms and other white rot fungi have proved their inherent capacity to biodegrade xenobiotic compounds, which otherwise take quite long time for their complete mineralization. This bioremediation employing mushrooms and other white rot fungi is gaining wide popularity as a mycoremediation technique.

Mycoremediation has a versatile role in environmental protection. Mycoremediation is an ecofriendly, noninvasive, cheaper, and easy solution that can reduce or transform environmental hazards into nontoxic or harmless forms (Perelo, 2010). Mushrooms are the most powerful disintegrators of by-products and are an essential component of the food web (Rhodes, 2012). Fungus cannot directly demolish the forest floor leafy covering and other woody material. First it covers the entire woody surface with white cotton or threads forming a huge mass of mycelium. The rate of degradation depends upon nutrients present in the soil. The more the nutrients the greater will be the decomposition rate. Many mushroom species such as Pleurotus ostreatus, Pleurotus tuber-regium, Pleurotus pulmonarius, Pleurotus eryngii, Lentinula edodes, Lentinus squarrosulus, Lentinus tigrinus, Agaricus bisporus, Nematolana prowardii, Irex lacteus, and Stropharia coronilla are strikingly suitable for interacting with intractable substrates, namely fats, chitin, and keratin, and degrade their starches, hemicellulases, celluloses, pectins, and other sugar polymers. In 1902 Flack developed an idea for improving the digestibility of lignocellulosic material by using white rot fungi (Flack, 1902). Several authors have examined the possibility of conversion of industrial waste by different fungi into valuable animal feed products. P. ostreatus occupies a great achievement in this category or field, as Pleurotus sp. shows very rapid growth on cotton stacks (Kerem, Friesem, & Hadar, 1992; Platt, Chet, & Henis, 1981). This key metabolic activity can also be applied to bioremediation of various pollutants which have structural similarities to lignin.

1.2 Bioremediation steps

Paul Stamets says “Fungi recycle and rebuild healthy soil in the area following any contamination incident (oil, spills, chemical leak, radiation agent)” (Stamets, 2005). Mushroom as a bioremediation tool helps to clean the Earth by disintegrating hazardous pollutants emerging from petroleum and chlorinated persistent pesticides (Rhodes, 2013). Bioremediation of wastes/pollutants includes three major steps: biodegradation, biosorption, and bioconversion (Fig. 1.1).

Figure 1.1 Mechanism of mycoremediation.

1.2.1 Biodegradation

Biodegradation means degradation of organic material in the environment by living organisms without a deleterious effect on nature. Different types of waste such as field wastes (weeds, straw), animal wastes (animal dung, dead bodies), agroindustrial wastes (sugarcane molasses, peels), paddy straw, jute fibers, groundnut, and woolen mill waste can be degraded by fungi reducing, recycling, and making it usable in a significant way. Several countries have adopted biodegradation as one of best steps for environmental protection from waste and hazardous materials.

Biodegra...

Table of contents

• Cover image
• Title page
• Table of Contents
• Copyright
• List of Contributors
• Chapter 1. Mushroom mycoremediation: kinetics and mechanism
• Chapter 2. Omics technology to study bioremediation and respective enzymes
• Chapter 3. Enzymology of the nitrogen cycle and bioremediation of toxic nitrogenous compounds
• Chapter 4. Effects of xenobiotics and their biodegradation in marine life
• Chapter 5. Role of keratinase in bioremediation of feathers and hairs
• Chapter 6. Enzymatic bioremediation: a smart tool to fight environmental pollutants
• Chapter 7. Regional impact of psychrophilic bacteria on bioremediation
• Chapter 8. Biotechnological and microbial standpoint cahoot in bioremediation
• Chapter 9. Significance of soil enzymes in agriculture
• Chapter 10. Comparative analysis of fungal and bacterial enzymes in biodegradation of xenobiotic compounds
• Chapter 11. Omics approaches for elucidating molecular mechanisms of microbial bioremediation
• Chapter 12. Major metabolites after degradation of xenobiotics and enzymes involved in these pathways
• Chapter 13. Microbial keratinase: a tool for bioremediation of feather waste
• Chapter 14. Biodegradation of toxic dyes: a comparative study of enzyme action in a microbial system
• Chapter 15. Phytoremediation facilitating enzymes: an enzymatic approach for enhancing remediation process
• Chapter 16. Bioremediation of petroleum hydrocarbon-polluted soil using microbial enzymes
• Chapter 17. Microorganisms: an asset for decontamination of soil
• Chapter 18. System biology, simulation, and network analysis of enzymes in waste removal from the environment
• Chapter 19. Evaluation of horizontal gene transfer of catabolic genes and its application in bioremediation
• Index