Biotechnology of Microbial Enzymes (2^nd Ed.)
Production, Biocatalysis, and Industrial Applications

Biotechnology of Microbial Enzymes: Production, Biocatalysis, and Industrial Applications, Second Edition provides a complete survey of the latest innovations on microbial enzymes, highlighting biotechnological advances in their production and purification along with information on successful applications as biocatalysts in several chemical and industrial processes under mild and green conditions.

The application of recombinant DNA technology within industrial fermentation and the production of enzymes over the last three decades have produced a host of useful chemical and biochemical substances. The power of these technologies results in novel transformations, better enzymes, a wide variety of applications, and the unprecedented development of biocatalysts through the ongoing integration of molecular biology methodology, all of which is covered insightfully and in-depth within the book.

This fully revised, second edition is updated to address the latest research developments and applications in the field, from microbial enzymes recently applied in drug discovery to penicillin biosynthetic enzymes and penicillin acylase, xylose reductase, and microbial enzymes used in antitubercular drug design. Across the chapters, the use of microbial enzymes in sustainable development and production processes is fully considered, with recent successes and ongoing challenges highlighted.

1. Biotechnology of microbial enzymes: production, biocatalysis, and industrial applications—an overview Goutam Brahmachari

1.1 Introduction 1.2 An overview of the book  1.2.1 Chapter 2  1.2.2 Chapter 3  1.2.3 Chapter 4  1.2.4 Chapter 5  1.2.5 Chapter 6  1.2.6 Chapter 7  1.2.7 Chapter 8  1.2.8 Chapter 9  1.2.9 Chapter 10  1.2.10 Chapter 11  1.2.11 Chapter 12  1.2.12 Chapter 13  1.2.13 Chapter 14  1.2.14 Chapter 15  1.2.15 Chapter 16  1.2.16 Chapter 17  1.2.17 Chapter 18  1.2.18 Chapter 19  1.2.19 Chapter 20  1.2.20 Chapter 21  1.2.21 Chapter 22  1.2.22 Chapter 23  1.2.23 Chapter 24  1.2.24 Chapter 25  1.2.25 Chapter 26 1.3 Concluding remarks

2. Useful microbial enzymes—an introduction Beatriz Ruiz-Villafa´n, Romina Rodri´guez-Sanoja and Sergio Sa´nchez

 2.1 The enzymes: a class of useful biomolecules  2.2 Microbial enzymes for industry  2.3 Improvement of enzymes  2.4 Discovery of new enzymes  2.5 Concluding remarks  Acknowledgments  Abbreviations  References

3. Production, purification, and application of microbial enzymes Anil Kumar Patel, Cheng-Di Dong, Chiu-Wen Chen, Ashok Pandey and Reeta Rani Singhania

 3.1 Introduction  3.2 Production of microbial enzymes   3.2.1 Enzyme production in industries   3.2.2 Industrial enzyme production technology  3.3 Strain improvements   3.3.1 Mutation   3.3.2 Recombinant DNA technology   3.3.3 Clustered regularly interspaced short palindromic repeats-Cas9 technology   3.3.4 Protein engineering  3.4 Downstream processing/enzyme purification  3.5 Product formulations  3.6 Global enzyme market scenarios  3.7 Industrial applications of enzymes   3.7.1 Food industry   3.7.2 Textile industry   3.7.3 Detergent industry   3.7.4 Pulp and paper industry   3.7.5 Animal feed industry   3.7.6 Leather industry   3.7.7 Biofuel from biomass   3.7.8 Enzyme applications in the chemistry and pharma sectors  3.8 Concluding remarks  Abbreviations  References

4. Solid-state fermentation for the production of microbial cellulases Sudhanshu S. Behera, Ankush Kerketta and Ramesh C. Ray

 4.1 Introduction  4.2 Solid-state fermentation   4.2.1 Comparative aspects of solid-state and submerged fermentations   4.2.2 Cellulase-producing microorganisms in solid-state fermentation   4.2.3 Extraction of microbial cellulase in solid-state fermentation   4.2.4 Measurement of cellulase activity in solid-state fermentation  4.3 Lignocellulosic residues/wastes as solid substrates in solid-state fermentation  4.4 Pretreatment of agricultural residues   4.4.1 Physical pretreatments   4.4.2 Physiochemical pretreatment   4.4.3 Chemical pretreatments   4.4.4 Biological pretreatment  4.5 Environmental factors affecting microbial cellulase production in solid-state fermentation   4.5.1 Water activity/moisture content   4.5.2 Temperature   4.5.3 Mass transfer processes: aeration and nutrient diffusion   4.5.4 Substrate particle size   4.5.5 Other factors  4.6 Strategies to improve production of microbial cellulase   4.6.1 Metabolic engineering and strain improvement   4.6.2 Recombinant strategy (heterologous cellulase expression)   4.6.3 Mixed-culture (coculture) systems  4.7 Fermenter (bioreactor) design for cellulase production in solid-state fermentation   4.7.1 Tray bioreactor   4.7.2 Packed bed reactor   4.7.3 Rotary drum bioreactor   4.7.4 Fluidized bed reactor  4.8 Biomass conversions and application of microbial cellulase   4.8.1 Textile industry   4.8.2 Laundry and detergent   4.8.3 Paper and pulp industry   4.8.4 Bioethanol and biofuel production   4.8.5 Food industry   4.8.6 Agriculture  4.9 Concluding remarks  Abbreviations  References

5. Hyperthermophilic subtilisin-like proteases from Thermococcus kodakarensis Ryo Uehara, Hiroshi Amesaka, Yuichi Koga, Kazufumi Takano, Shigenori Kanaya and Shun-ichi Tanaka

 5.1 Introduction  5.2 Two Subtilisin-like proteases from Thermococcus Kodakarensis KOD1  5.3 TK-subtilisin   5.3.1 Ca21-dependent maturation of Tk-subtilisin   5.3.2 Crystal structures of Tk-subtilisin   5.3.3 Requirement of Ca21-binding loop for folding   5.3.4 Ca21 ion requirements for hyperstability   5.3.5 Role of Tkpro   5.3.6 Role of the insertion sequences   5.3.7 Cold-adapted maturation through Tkpro engineering   5.3.8 Degradation of PrPSc by Tk-subtilisin   5.3.9 Tk-subtilisin pulse proteolysis experiments  5.4 Tk-SP   5.4.1 Maturation of Pro-Tk-SP   5.4.2 Crystal structure of Pro-S359A   5.4.3 Role of proN   5.4.4 Role of the C-domain   5.4.5 PrPSc degradation by Tk-SP  5.5 Concluding remarks  Acknowledgments  Abbreviations  References

6. Enzymes from basidiomycetes—peculiar and efficient tools for biotechnology Thai´s Marques Uber, Emanueli Backes, Vini´cius Mateus Salvatore Saute, Bruna Polacchine da Silva, Rubia Carvalho Gomes Correˆ a, Camila Gabriel Kato, Fla´vio Augusto Vicente Seixas, Adelar Bracht and Rosane Marina Peralta

 6.1 Introduction  6.2 Brown- and white-rot fungi  6.3 Isolation and laboratory maintenance of wood-rot basidiomycetes  6.4 Basidiomycetes as producers of enzymes involved in the degradation of lignocellulose biomass   6.4.1 Enzymes involved in the degradation of cellulose and hemicelluloses   6.4.2 Enzymes involved in lignin degradation  6.5 Production of ligninolytic enzymes by basidiomycetes: screening and production in laboratory scale  6.6 General characteristics of the main ligninolytic enzymes with potential biotechnological applications   6.6.1 Laccases   6.6.2 Peroxidases  6.7 Industrial and biotechnological applications of ligninolytic enzymes from basidiomycetes   6.7.1 Application of ligninolytic enzymes in delignification of vegetal biomass and biological detoxification for biofuel production   6.7.2 Application of ligninolytic enzymes in the degradation of xenobiotic compounds   6.7.3 Application of ligninolytic enzymes in the degradation of textile dyes   6.7.4 Application of ligninolytic enzymes in pulp and paper industry  6.8 Concluding remarks  Acknowledgments  Abbreviations  References

7. Metagenomics and new enzymes for the bioeconomy to 2030 Patricia Molina-Espeja, Cristina Coscoli´n, Peter N. Golyshin and Manuel Ferrer

 7.1 Introduction  7.2 Metagenomics  7.3 Activity-based methods for enzyme search in metagenomes  7.4 Computers applied to metagenomic enzyme search  7.5 Concluding remarks  Acknowledgments  References

8. Enzymatic biosynthesis of ß-lactam antibiotics Swati Srivastava, Reeta Bhati and Rajni Singh

 8.1 Introduction  8.2 Enzymes involved in the biosynthesis of ß-lactam antibiotics   8.2.1 Isopenicillin N synthase   8.2.2 ß-Lactam synthetase   8.2.3 Carbapenam synthetase (Cps)   8.2.4 Tabtoxinine ß-lactam synthetase (Tbl S)   8.2.5 Deacetoxycephalosporin C synthase and deacetylcephalosporin C synthase   8.2.6 Clavaminic acid synthase   8.2.7 Nonribosomal peptide synthetases  8.3 Semisynthetic ß-lactam derivatives  8.4 Concluding remarks  Abbreviations  References

9. Insights into the molecular mechanisms of ß-lactam antibiotic synthesizing and modifying enzymes in fungi Juan F. Marti´n, Carlos Garci´a-Estrada and Paloma Liras

 9.1 Introduction   9.1.1 Penicillin and cephalosporin biosynthesis: a brief overview   9.1.2 Genes involved in penicillin and cephalosporin biosynthesis  9.2 ACV synthetase   9.2.1 The ACV assembly line   9.2.2 The cleavage function of the integrated thioesterase domain  9.3 Isopenicillin N synthase   9.3.1 Binding and lack of cyclization of the LLL-ACV   9.3.2 The iron-containing active center   9.3.3 The crystal structure of isopenicillin N synthase   9.3.4 Recent advances in the cyclization mechanism  9.4 Acyl-CoA ligases: a wealth of acyl-CoA ligases activate penicillin side-chain precursors  9.5 Isopenicillin N acyltransferase (IAT)   9.5.1 Posttranslational maturation of the IAT   9.5.2 The IPN/6-APA/PenG substrate-binding pocket   9.5.3 A transient acyl-IAT intermediate   9.5.4 The origin of IAT: an homologous AT in many fungal genomes  9.6 Transport of intermediates and penicillin secretion   9.6.1 Transport of isopenicillin N into peroxisomes   9.6.2 IAT is easily accessible to external 6-APA   9.6.3 Intracellular traffic of intermediates and secretion of penicillins  9.7 Production of semisynthetic penicillins by penicillin acylases   9.7.1 Molecular mechanisms of penicillin acylases   9.7.2 Novel developments in industrial applications of penicillin acylases  9.8 Concluding remarks  Abbreviations  References

10. Role of glycosyltransferases in the biosynthesis of antibiotics Pankaj Kumar, Sanju Singh, Vishal A. Ghadge, Harshal Sahastrabudhe, Meena R. Rathod and Pramod B. Shinde    10.1 Introduction  10.2 Classification and structural insights of glycosyltransferases  10.3 Role of glycosylation in enhancing bioactivity   10.3.1 Vancomycin   10.3.2 Tiacumicin B   10.3.3 Amycolatopsins   10.3.4 Digitoxin   10.3.5 Aminoglycosides  10.4 Engineering biosynthetic pathway of antibiotics by altering glycosyltransferases   10.4.1 Combinatorial biosynthesis   10.4.2 Glycorandomization  10.5 Identification of glycosyltransferases and glycosylated molecules using bioinformatics  10.6 Concluding remarks  Abbreviations  References

11. Relevance of microbial glucokinases Beatriz Ruiz-Villafa´n, Diana Rocha, Alba Romero and Sergio Sa´nchez

 11.1 Introduction  11.2 Synthesis, biochemical properties, and regulation  11.3 Structure  11.4 Catalytic mechanism  11.5 Production  11.6 Potential applications in industrial processes  11.7 Concluding remarks  Acknowledgments  References

12. Myctobacterium tuberculosis DapA as a target for antitubercular drug design Ayushi Sharma, Ashok Kumar Nadda and Rahul Shrivastava

 12.1 Introduction   12.1.1 Tuberculosis: global epidemiology  12.2 Challenges encountered by the scientific communities  12.3 MTB cell wall: a source of drug targets   12.3.1 Targeting MTB cell wall enzymes  12.4 The diaminopimelate (DAP) pathway (lysine synthesis pathway)  12.5 Dihydrodipicolinate synthase (DapA)   12.5.1 Structure of MTB DapA   12.5.2 Action mechanism of MTB DapA   12.5.3 Active site of MTB DapA   12.5.4 Kinetic parameters of MTB DapA   12.5.5 Regulation of MTB DapA activity   12.5.6 Inhibitors against MTB DapA  12.6 Previous experiments targeting MTB Dap pathway enzymes  12.7 Significance of inhibitors against MTB Dap pathway enzymes  12.8 Concluding remarks  Acknowledgment  Abbreviations  References

13. Lipase-catalyzed organic transformations: a recent update Goutam Brahmachari

 13.1 Introduction  13.2 Chemoenzymatic applications of lipases in organic transformations: a recent update  13.3 Concluding remarks  References

14. Tyrosinase and Oxygenases: Fundamentals and Applications Shagun Sharma, Kanishk Bhatt, Rahul Shrivastava and Ashok Kumar Nadda

 14.1 Introduction  14.2 Origin and Sources   14.2.1 Tyrosinase   14.2.2 Oxygenase  14.3 Molecular Structure of Tyrosinase and Oxygenase   14.3.1 Molecular structure of Tyrosinase   14.3.2 Oxygenase  14.4 Mechanism of Catalytic Action   14.4.1 Tyrosinase: mechanism of the reaction   14.4.2 Oxygenase  14.5 Applications of Tyrosinase and Oxygenase   14.5.1 Biological applications   14.5.2 Applications in food industry   14.5.3 Applications in bioremediation   14.5.4 Medicinal applications   14.5.5 Industrial applications  14.6 Concluding Remarks  Acknowledgement  Abbreviations  References

15. Application of microbial enzymes as drugs in human therapy and healthcare Miguel Arroyo, Isabel de la Mata, Carlos Barreiro, Jose´ Luis Garci´a and Jose´ Luis Barredo

 15.1 Introduction  15.2 Manufacture of therapeutic enzymes   15.2.1 Production and purification   15.2.2 Preparation of “single-enzyme nanoparticles”: SENization   15.2.3 Oral enzyme therapy  15.3 Examples of microbial enzymes aimed at human therapy and healthcare   15.3.1 “Clot buster” microbial enzymes   15.3.2 Microbial enzymes as digestive aids   15.3.3 Microbial enzymes for the treatment of congenital diseases   15.3.4 Microbial enzymes for the treatment of infectious diseases: enzybiotics   15.3.5 Microbial enzymes for burn debridement and fibroproliferative diseases: collagenase   15.3.6 Enzymes for the treatment of cancer   15.3.7 Other enzymes for the treatment of other health disorders  15.4 Concluding remarks  Abbreviations  References

16. Microbial enzymes in pharmaceutical industry Nidhi Y. Patel, Dhritiksha M. Baria, Dimple S. Pardhi, Shivani M. Yagnik, Rakeshkumar R. Panchal, Kiransinh N. Rajput and Vikram H. Raval

 16.1 Introduction  16.2 Cataloging of hydrolases used in pharmaceutical industry  16.3 Microbial enzymes in pharmaceutical processes   16.3.1 Therapeutics   16.3.2 Antiinflammatory   16.3.3 Enzybiotics  16.4 Concluding remarks  Abbreviations  References

17. Microbial enzymes of use in industry Xiangyang Liu and Chandrakant Kokare

 17.1 Introduction  17.2 Classification and chemical nature of microbial enzymes   17.2.1 Amylases   17.2.2 Catalases   17.2.3 Cellulases   17.2.4 Lipases   17.2.5 Pectinases   17.2.6 Proteases   17.2.7 Xylanases   17.2.8 Other enzymes  17.3 Production of microbial enzymes   17.3.1 Fermentation methods   17.3.2 Purification methods  17.4 Applications of microbial enzymes   17.4.1 Plastic/polymer biodegradation   17.4.2 Food and beverage   17.4.3 Detergents   17.4.4 Removal of pollutants   17.4.5 Textiles   17.4.6 Animal feed   17.4.7 Ethanol production   17.4.8 Other applications  17.5 Future of microbial enzymes  17.6 Concluding remarks  References

18. Microbial enzymes used in food industry Pedro Fernandes and Filipe Carvalho

 18.1 Introduction   18.1.1 A global perspective on the use of enzymes in the food industry   18.1.2 Identification/improvement of the right biocatalyst   18.1.3 Enzyme sources and safety issues  18.2 Microbial enzymes in food industry   18.2.1 Production of enzymes for food processing   18.2.2 Formulation of enzymes for use in food processing   18.2.3 Granulation of enzymes   18.2.4 Tablets   18.2.5 Immobilization   18.2.6 Applications in food industries  18.3 Concluding remarks  Abbreviations  References

19. Carbohydrases: a class of all-pervasive industrial biocatalysts Archana S. Rao, Ajay Nair, Hima A. Salu, K.R. Pooja, Nandini Amrutha Nandyal, Venkatesh S. Joshi, Veena S. More, Niyonzima Francois, K.S. Anantharaju and Sunil S. More

 19.1 Introduction  19.2 Classification of carbohydrases   19.2.1 Glycosidases   19.2.2 Glycosyltransferase   19.2.3 Glycosyl phosphorylases   19.2.4 Polysaccharide lyases   19.2.5 Carbohydrate esterases  19.3 Sources   19.3.1 Marine microorganisms   19.3.2 Rumen bacteria   19.3.3 Genetically modified organisms   19.3.4 Fungi and yeasts  19.4 Industrial production of carbohydrase   19.4.1 Enzyme immobilization  19.5 Industrial applications of carbohydrases   19.5.1 Enzymes involved in the production of beverages   19.5.2 Enzymes involved in the production of prebiotics   19.5.3 Enzymes involved in syrup and isomaltulose production   19.5.4 Enzymes in dairy industry   19.5.5 Carbohydrases in animal feed production   19.5.6 Carbohydrase application in pharmaceutical industries   19.5.7 Carbohydrases involved in detergent   19.5.8 Carbohydrases in wastewater treatment   19.5.9 Agriculture   19.5.10 Enzymes in textile industry   19.5.11 Carbohydrases involved in biofuel production   19.5.12 Carbohydrases involved in paper industry  19.6 Concluding remarks  Abbreviations  References

20. Role of microbial enzymes in agricultural industry Prashant S. Arya, Shivani M. Yagnik and Vikram H. Raval

 20.1 Introduction  20.2 Soil and soil bacteria for agriculture  20.3 Microbial enzymes   20.3.1 Nitro-reductase   20.3.2 Hydrolases   20.3.3 1-Aminocyclopropane-1-carboxylic acid deaminase   20.3.4 Phosphate-solubilizing enzymes   20.3.5 Sulfur-oxidizing and reducing enzymes   20.3.6 Oxidoreductases   20.3.7 Zinc-solubilizing enzymes  20.4 Microbial enzymes for crop health, soil fertility, and allied agro-industries   20.4.1 Crop health (assessment via biocontrol agents)   20.4.2 Soil fertility (indicator enzymes)   20.4.3 Allied agro-industrial applications  20.5 Agricultural enzyme market  20.6 Concluding remarks  Abbreviations  References

21. Opportunities and challenges for the production of fuels and chemicals: materials and processes for biorefineries Carolina Reis Guimara˜ es, Ayla Sant’Ana da Silva, Daniel Oluwagbotemi Fasheun, Denise M.G. Freire, Elba P.S. Bon, Erika Cristina G. Aguieiras, Jaqueline Greco Duarte, Marcella Fernandes de Souza, Mariana de Oliveira Faber, Marina Cristina Tomasini, Roberta Pereira Espinheira, Ronaldo Rodrigues de Sousa, Ricardo Sposina Sobral Teixeira and Viridiana S. Ferreira-Leita˜o

 21.1 Introduction  21.2 Brazilian current production and processing of lignocellulosic sugarcane biomass   21.2.1 Cellulosic ethanol: worldwide production and feedstock description   21.2.2 Lignocellulosic biomass components and biomass-degrading enzymes   21.2.3 Perspectives and difficulties of cellulosic ethanol production   21.2.4 Enzyme-based initiatives for ethanol production at commercial scale   21.2.5 Perspectives on the use of microalgae as sources of fermentable sugars  21.3 Technical and economic prospects of using lipases in biodiesel production   21.3.1 Current biodiesel production and perspectives   21.3.2 Biocatalytic production of biodiesel   21.3.3 Feedstocks used for biodiesel production   21.3.4 Enzymatic routes for biodiesel production   21.3.5 Enzymatic biodiesel: state of the art   21.3.6 Perspectives for enzymatic biodiesel production  21.4 Perspectives on biomass processing for composites and chemicals production  21.5 Biogas/biomethane production   21.5.1 Enzymes applied to improve anaerobic digestion   21.5.2 Generation and use of biogas/biomethane in Brazil   21.5.3 Hydrogen production   21.5.4 Sequential production of hydrogen and methane  21.6 Concluding remarks  Abbreviations  References

22. Use of lipases for the production of biofuels Thais de Andrade Silva, Julio Pansiere Zavarise, Igor Carvalho Fontes Sampaio, Laura Marina Pinotti, Servio Tulio Alves Cassini and Jairo Pinto de Oliveira

 22.1 Introduction  22.2 Lipases   22.2.1 Immobilization of lipases   22.2.2 Immobilization methods and supports  22.3 Feedstocks   22.3.1 Vegetable oils   22.3.2 Animal fats   22.3.3 Oily waste   22.3.4 Microalgae oil and biomass  22.4 Catalytic process   22.4.1 Effect of temperature   22.4.2 Effect of water content   22.4.3 Effect of acyl acceptor   22.4.4 Effect of solvent   22.4.5 Effect of molar ratio   22.5 Reactors and industrial processes   22.6 Concluding remarks  References

23. Microbial enzymes used in textile industry Francois N. Niyonzima, Veena S. More, Florien Nsanganwimana, Archana S. Rao, Ajay Nair, K.S. Anantharaju and Sunil S. More

 23.1 Introduction  23.2 Isolation and identification of microorganism-producing textile enzymes  23.3 Production of textile enzymes by bacteria and fungi  23.4 Process aspect optimization for producing microbial textile enzymes   23.4.1 Effect of initial pH medium for the secretion of textile enzymes by microorganisms   23.4.2 Influence of incubation temperature on the production of textile enzymes by microorganisms   23.4.3 Effect of agitation on the secretion of textile enzymes by microorganisms   23.4.4 Influence of inoculum concentration on the production of textile enzymes by microorganisms   23.4.5 Effect of initial time on the secretion of textile enzymes by microorganisms   23.4.6 Influence of carbon sources on the production of textile enzymes by microorganisms   23.4.7 Effect of nitrogen sources on the production of textile enzymes by microorganisms  23.5 Purification strategies of textile enzymes  23.6 Microbial enzymes used in the textile industry   23.6.1 Biodesizing by a-amylases   23.6.2 Bioscouring by pectinases aided by proteases, cutinases, and lipases   23.6.3 Biostone-washing by neutral cellulases   23.6.4 Biobleaching by laccases, catalases, and peroxidases   23.6.5 Biodyeing and printing by pectinases and peroxidases   23.6.6 Biopolishing/biofinishing by acid cellulases   23.6.7 Use of the mixture of microbial enzymes in textile fabric material processing  23.7 Immobilization of textile enzymes  23.8 Genetic engineering of bacteria- and fungi-producing textile enzymes  23.9 Manufacturers of some commercial textile enzymes  23.10 Textile industry effluents’ treatment  23.11 Concluding remarks  References

24. Microbial enzymes in bioremediation Shivani M. Yagnik, Prashant S. Arya and Vikram H. Raval

 24.1 Introduction  24.2 Robust microbes/superbugs in bioremediation   24.2.1 Xenobiotic and persistent compounds   24.2.2 Robust microbes and their application in bioremediation   24.2.3 Metabolic pathway engineering for high-speed bioremediation  24.3 Role of microbial enzymes   24.3.1 Dye degradation   24.3.2 Remediation of hydrocarbon and benzene, toluene, ethylbenzene, and xylene compounds   24.3.3 Heavy metal remediation   24.3.4 Pesticide degradation  24.4 Remedial applications for industries   24.4.1 Designing and developing environmental biosensor   24.4.2 Immobilization and bioengineering   24.4.3 Biotransformation and bioleaching  24.5 Concluding remarks  Abbreviations  References

25. The role of microbes and enzymes for bioelectricity generation: a belief toward global sustainability Lakshana Nair G, Komal Agrawal and Pradeep Verma

 25.1 Introduction  25.2 Bioresources: biorefinery  25.3 Hydrolytic enzymes and their applications in various sectors   25.3.1 Ligninolytic enzymes   25.3.2 Laccases   25.3.3 Cellulases   25.3.4 Xylanases   25.3.5 Amylases   25.3.6 Pectinases   25.3.7 Lytic polysaccharide monooxygenases   25.3.8 Lipases  25.4 Bioelectricity and microbial electrochemical system   25.4.1 Working of the microbial fuel cell   25.4.2 Use of wastes for electricity generation   25.4.3 Hydrolytic enzymes in microbial fuel cell  25.5 Limitations and their possible solutions in biorefinery and bioelectricity generation  25.6 Prospects  25.7 Concluding remarks  Abbreviations  References

26. Discovery of untapped nonculturable microbes for exploring novel industrial enzymes based on advanced next-generation metagenomic approach Shivangi Mudaliar, Bikash Kumar, Komal Agrawal and Pradeep Verma

26.1 Introduction 26.2 Need for nonculturable microbe study 26.3 Problems associated with nonculturable microbial studies 26.3.1 Relationship with coexisting microbes 26.4 Culture-independent molecular-based methods 26.4.1 Isolation of sample DNA 26.4.2 Metagenomic library construction 26.4.3 Metagenomics 26.4.4 Metatranscriptomics 26.4.5 Metaproteomic 26.5 Different approaches for metagenomic analysis of unculturable microbes 26.5.1 Sequence-based screening 26.5.2 Function-based screening 26.6 Next-generation sequencing and metagenomics 26.6.1 Benefits of metagenomic next-generation sequencing 26.7 Application of unculturable microbes and significance of next-generation metagenomic approaches 26.7.1 Agricultural applications 26.7.2 Clinical diagnosis 26.7.3 Xenobiotic degradation 26.7.4 Industrial applications 26.7.5 Bioeconomy 26.8 Concluding remarks

Conflict of interest Abbreviations References Index

• Explores advances in microbial enzymes from basic science through application in multiple industry sectors
• Includes up-to-date discussions of metabolic pathway engineering, metagenomic screening, microbial genomes, extremophiles, rational design, directed evolution, and more
• Provides a holistic approach to the research of microbial enzymes and their use in sustainable processes and innovation
• Features all new chapters discussing microbial enzyme classes of growing interest, as well as enzymes recently applied in drug discovery and other applications