Biotechnology of Microbial Enzymes

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 Rodrı´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
Thaı´s Marques Uber, Emanueli Backes, Vinı´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 Coscolı´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 β-lactam antibiotics
Swati Srivastava, Reeta Bhati and Rajni Singh

 8.1 Introduction
 8.2 Enzymes involved in the biosynthesis of β-lactam antibiotics
  8.2.1 Isopenicillin N synthase
  8.2.2 β-Lactam synthetase
  8.2.3 Carbapenam synthetase (Cps)
  8.2.4 Tabtoxinine β-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 β-lactam derivatives
 8.4 Concluding remarks
 Abbreviations
 References

9. Insights into the molecular mechanisms of β-lactam antibiotic synthesizing and modifying enzymes in fungi
Juan F. Martı´n, Carlos Garcı´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 Garcı´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 α-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