Table of Contents

Cover

Title Page

Dedication

List of Contributors

Introduction

Chapter 1: Introduction of Natural Pigments from Microorganisms

1.1 Introduction
1.2 Microbial Pigments from Eukaryotic Sources
1.3 Natural Pigments from Prokaryotes
1.4 Conclusion
References

Chapter 2: Establishing Novel Cell Factories Producing Natural Pigments in Europe

2.1 Introduction
2.2 Colorants
2.3 Screening for Monascus Pigment-Producing Cell Factories for the European Market
2.4 Assessment of the Color Yield
2.5 Optimizing Cellular Performance: Growth and Pigment Production
2.6 Pigment Properties
2.7 Conclusion
References

Chapter 3: Color-Producing Extremophiles

3.1 Introduction
3.2 Color-Producing Extremophiles
3.3 Microbial Pigments
3.4 Biotechnological Applications of Microbial Pigments from Extremophiles
3.5 Conclusion
Acknowledgments
References

Chapter 4: Current Carotenoid Production Using Microorganisms

4.1 Introduction
4.2 β-carotene
4.3 Lycopene
4.4 Astaxanthin
4.5 Zeaxanthin
4.6 Canthaxanthin
4.7 Torulene and Thorularhodin
4.8 Prospects for Carotenoid Production by Genetically Modified Microorganisms
4.9 Conclusion
References

Chapter 5: C50 Carotenoids: Occurrence, Biosynthesis, Glycosylation, and Metabolic Engineering for their Overproduction

5.1 Introduction
5.2 Occurrence and Biological Function of C50 Carotenoids
5.3 Biosynthesis of C50 Carotenoids
5.4 Glycosylation of C50 Carotenoids
5.5 Overproduction of C50 Carotenoids by Metabolic Engineering
5.6 Conclusion
Acknowledgments
References

Chapter 6: Biopigments and Microbial Biosynthesis of β-carotenoids

6.1 Introduction
6.2 Characterization of Biological Pigments
6.3 Biosynthetic Routes of β-carotene
6.4 Molecular Regulation of β-carotene Biosynthesis
6.5 Commercialization of β-carotene
6.6 Conclusion
References

Chapter 7: Biotechnological Production of Melanins with Microorganisms

7.1 Introduction
7.2 Microbial Production of Melanins
7.3 Production of Melanins with Engineered Microorganisms
7.4 Conclusion
References

Chapter 8: Biochemistry and Molecular Mechanisms of Monascus Pigments

8.1 Introduction
8.2 Monascus Pigments
8.3 The Properties of Monascus Pigments
8.4 Functional Properties of Monascus Pigments
8.5 Biosynthetic Pathway of Monascus Pigments
8.6 Biosynthetic Pathway of Related Genes
8.7 Factors Affecting Monascus Pigment Production
References

Chapter 9: Diversity and Applications of Versatile Pigments Produced by Monascus sp

9.1 Introduction
9.2 Pigment-Producing Monascus Strains
9.3 Various Types of Monascus Pigments
9.4 Extraction and Purification of Monascus Pigments
9.5 Detection and Purification
9.6 Applications
9.7 Conclusion
Acknowledgments
References

Chapter 10: Microbial Pigment Production Utilizing Agro-industrial Waste and Its Applications

10.1 Introduction
10.2 Agro-industrial Waste Generation: A Scenario
10.3 Microbial Pigments
10.4 Production of Microbial Pigments Utilizing Agro-industrial Waste from Different Industries
10.5 Case Study: Production of Violacein by Chromobacterium violaceum Grown in Agricultural Wastes
10.6 Conclusion
Acknowledgments
References

Chapter 11: Microbial Pigments: Potential Functions and Prospects

11.1 Introduction
11.2 Potential Sources of Microbial Pigments
11.3 Physical Factors Influencing Microbial Pigments
11.4 Chemical Factors Influencing Microbial Pigments
11.5 Fermentation Practices in Pigment Production
11.6 Characterization and Purification Analysis
11.7 Biocolors from Microbes and their Potential Functions
References

Chapter 12: The Microbial World of Biocolor Production

12.1 Introduction
12.2 Pigments Produced by Microorganisms
12.3 Classification of Pigments
12.4 Benefits and Applications of Microbial Pigments
12.5 Conclusion
References

Index

End User License Agreement

List of Illustrations

Chapter 1: Introduction of Natural Pigments from Microorganisms

Figure 1.1 Structures of four representative carotenoids: β-carotene, lutein, canthaxanthin, and astaxanthin.
Figure 1.2 Nine representative fungal pigments: riboflavin, monascin, ankaflavin, rubropunctatin, monascorubramine, atrovenetin, herqueinone, bikaverin, and catenarin.
Figure 1.3 Structures of melanin and biliverdin.
Figure 1.4 Structures of phycocyanbilin and phycoerythrobilin.
Figure 1.5 Biosynthetic pathway of scytonemin.
Figure 1.6 Structures of five bacterial pigments: zeaxanthin, xanthomonadin I, prodigiosin, violacein, and actinorhodin.
Figure 1.7 Indigo (from plants) and indigoidine (from bacteria). (a) Structure of indigo. (b) Biosynthetic pathway of indigoidine.
Figure 1.8 Biosynthetic pathway of flaviolin.

Chapter 2: Establishing Novel Cell Factories Producing Natural Pigments in Europe

Figure 2.1 Percentage market share of food colorants in 2014 (Wissgott and Bortlik 1996).
Figure 2.2 Chemical structures of the original six Monascus pigments.
Figure 2.3 Monascus pigment biosynthesis based on a proposal by Balakrishnan et al. (2013).
Figure 2.4 Chemical structures of monascus pigment derivatives associated with T. atroroseus.
Figure 2.5 Major steps in the establishment of a successful cell factory.
Figure 2.6 Steps in product identification when establishing a novel cell factory.
Figure 2.7 Yellow, orange, and red UV spectra from three Monascus pigments: monascine (yellow), monascorubrine (orange), and rubropunctamine (red).
Figure 2.8 Interactions to consider when implementing novel cell factories for pigment production.

Chapter 3: Color-Producing Extremophiles

Figure 3.1 Representative environments of extremophiles. (a) Acid waters in Tinto River, Spain. (b) Red snow in Antarctica. (c) Stromatolites from Amarga Lagoon in Torres del Paine, Chile. (d) Uzon Caldera (e) and Geyser Valley, Kamchatka. (f) Salty environment in Santa Pola salterns, Spain.
Figure 3.2 Pigment synthesis at increasing temperature. Bacterial cultures of S. oneidensis (upper panel) and S. frigidimarina (bottom panel) incubated at 0, 4, 15, 20, and 30 °C. An intense reddish color can be observed in cells cultured at higher temperatures.
Figure 3.3 Cytochrome c3 protein network. Theoretical prediction obtained with String v. 10.0 (http://string-db.org) of the functional protein association network of cytochrome c3 from the antarctic bacteria S. frigidimarina.
Figure 3.4 Examples of the applications of pigments obtained from color-producing extremophiles. New environmental microorganisms are being isolated and cultured as a source of pigments used in the food, pharmaceutical, and textile industries, in environmental decontamination, in the research of laboratory tools, and in the development of microbial fuel cells.

Chapter 4: Current Carotenoid Production Using Microorganisms

Figure 4.1 Metabolic engineering of microbial carotenoid production.

Chapter 5: C50 Carotenoids: Occurrence, Biosynthesis, Glycosylation, and Metabolic Engineering for their Overproduction

Figure 5.1 Structures of C50 carotenoids and schematic representation of their biosynthesis, starting from lycopene and leading to (a) decaprenoxanthin in C. glutamicum, (b) sarcinaxanthin in M. luteus, (c) C.p. 450 in Dietzia sp. CQ4, (d) bacterioruberin in H. japonica, and (e) C50-lycopene and C50-astaxanthin in recombinant E. coli. IPP, isopentenyl pyrophosphate; DMAPP, dimethylallyl pyrophosphate; GPP, geranyl pyrophosphate; FPP, farnesyl pyrophosphate; GGPP, geranylgeranyl pyrophosphate; CrtB, phytoene synthase; CrtI, phytoene desaturase; CrtEb/CrtE2, lycopene elongase; CrtY_e/f, C50 carotenoid ϵ-cyclase; CrtY_g/h, C50 carotenoid γ-cyclase; LbtBC, lycopene elongase; LbtAB, C50 carotenoid β-cyclase; LyeJ, bifunctional lycopene elongase and 1,2-hydratase; CrtD, carotenoid 3,4-desaturase; CruF, C50 carotenoid 2-″,3-″-hydratase; FDS^Y81A,V157A, farnesyl diphosphate synthase; CrtM^{F26A,W38A,F233S}, carotenoid synthase; CrtIN304P, carotenoid desaturase; CrtY, lycopene cyclase; CrtW, β-carotene ketolase; CrtZ, β-carotene hydroxylase. For further abbreviations see text.

Chapter 6: Biopigments and Microbial Biosynthesis of β-carotenoids

Figure 6.1 The MVA pathway for the biosynthesis of β-carotene in bacteria, fungi, and animals.
Figure 6.2 The proposed biosynthetic pathway leading to β-carotene. The bacterial crt genes required for conversions that are listed here apply to both photosynthetic and nonphotosynthtic bacteria. DMAPP, dimethylallyl pyrophosphate; IPP, isopentenyl pyrophosphate; GPP, geranyl pyrophosphate; FPP, farnesyl pyrophosphate; GGPP, geranylgeranyl pyrophosphate; PPPP, prephytoene pyrophosphate.
Figure 6.3 Biosynthesis of β-carotene via the MEP pathway in cynobacteria, microalgae, photosynthetic bacteria, and plants.

Chapter 7: Biotechnological Production of Melanins with Microorganisms

Figure 7.1 Metabolic pathways and expressed genes related to melanin synthesis in engineered Escherichia coli. Dashed arrows indicate two or more enzyme reactions. Underlined genes were overexpressed from plasmids. PTS, phosphotransferase system glucose transport protein; G6P, glucose-6-phosphate; E4P, D-erythrose 4-phosphate; PEP, phosphoenolpyruvate; DAHP, 3-deoxy-D-arabino-heptulosonate 7-phosphate; HPP, 4-hydroxyphenylpyruvate; L-Tyr L-tyrosine; L-Phe, L-phenylalanine; L-Trp, L-tryptophan; tktA, gene encoding transketolase; aroGfbr, gene encoding feedback inhibition-resistant DAHP synthase; tyrC, gene encoding cyclohexadienyl dehydrogenase; pheACM, gene encoding chorismate mutase domain from chorismate mutase-prephenate dehydratase.

Chapter 8: Biochemistry and Molecular Mechanisms of Monascus Pigments

Figure 8.1 Chemical structure of major Monascus pigments.
Figure 8.2 Chemical structures of four kinds of water-soluble Monascus pigments.
Figure 8.3 Predicted biosynthetic pathways of Monascus pigments.
Figure 8.4 Predicted biosynthetic pathway of yellow pigments.
Figure 8.5 Predicted biosynthetic pathway of orange pigments.
Figure 8.6 Predicted biosynthetic pathway of red pigments.
Figure 8.7 Monascus pigments synthetic gene cluster and predicted biosynthetic pathway in M. rubber. Source: Chen et al. (2015). Reproduced with permission of John Wiley & Sons.
Figure 8.8 Monascus pigments synthetic gene cluster and predicted biosynthetic pathway in M. pilosus. Source: Balakrishnan et al. (2013). Reproduced with permission of Springer.
Figure 8.9 Schematic representation of Monascus pigment production by solid-state fermentation.
Figure 8.10 Schematic representation of Monascus pigment production by submerged fermentation.

Chapter 9: Diversity and Applications of Versatile Pigments Produced by Monascus sp

Figure 9.1 Structures of major Monascus pigments.
Figure 9.2 Structures of minor Monascus pigments.
Figure 9.3 Structures of citrinin and monacolins.

Chapter 10: Microbial Pigment Production Utilizing Agro-industrial Waste and Its Applications

Figure 10.1 Growth profile of C. violaceum in nutrient broth.
Figure 10.2 Effect of time on pigment production on C. violaceum.
Figure 10.3 Growth profile of C. violaceum in nutrient broth at 25, 30, and 37 °C.
Figure 10.4 Absorption spectrum of the violet pigment obtained at different incubation temperatures.
Figure 10.5 Time course of cell growth and pH profile of C. violaceum cultivated in nutrient broth, tryptic soy broth, peptone glycerol broth, and luria-bertani medium.
Figure 10.6 Violacein production by C. violaceum in complex media.
Figure 10.7 Color intensity of pigments in (a) liquid substrate and (b) solid substrate.
Figure 10.8 Pigment production by C. violaceum grown in SCB, SPW, molasses, and brown sugar supplemented with 10% (v/v) L-tryptophan in distilled water. SCB, sugar cane bagasse; SPW, solid pineapple waste; BS, brown sugar; M, molasses.
Figure 10.9 Violacein production in SCB.

Chapter 11: Microbial Pigments: Potential Functions and Prospects

Figure 11.1 Structures of bacterial pigments.
Figure 11.2 Structures of fungal pigments.

Chapter 12: The Microbial World of Biocolor Production

Figure 12.1 Some food-grade pigments of microorganism origin and their structures (Venil et al. 2013).
Figure 12.2 Representation of various color-producing microorganisms on a Petri plate.

List of Tables

Chapter 2: Establishing Novel Cell Factories Producing Natural Pigments in Europe

Table 2.1 Potential Pigment Producers for the European Market
Table 2.2 Reported Optimal Process Conditions for T. atroroseus and Related Species

Chapter 3: Color-Producing Extremophiles

Table 3.1 Examples of Pigments from the Major Groups of Extremophiles
Table 3.2 Biotechnological Applications of Pigments from Extremophiles

Chapter 4: Current Carotenoid Production Using Microorganisms

Table 4.1 Sources of β-Carotene and β-Carotene-Containing Preparations
Table 4.2 Isomers Described in “β-Carotene” from Various Sources
Table 4.3 Comparison of the Chemical Compositions of Synthetic Lycopene, Lycopene from Tomatoes, and Lycopene from Blakeslea Trispora
Table 7.4 Microbial Production of Pigments (Already in Use as Natural Colorants or with High Potential in this Field)

Chapter 5: C50 Carotenoids: Occurrence, Biosynthesis, Glycosylation, and Metabolic Engineering for their Overproduction

Table 5.1 C50 Carotenoid Production Systems

Chapter 6: Biopigments and Microbial Biosynthesis of β-carotenoids

Table 6.1 Major Microorganisms Used for Natural Carotenoid Production
Table 6.2 Optimized Fermentation Media for Microbial Synthesis of Carotenoids
Table 6.3 Major Patents Relating to the β-Carotene Biosynthetic Process and Manufacture

Chapter 7: Biotechnological Production of Melanins with Microorganisms

Table 7.1 Common Types of Melanins and their Precursor Compounds
Table 7.2 Comparison of Microbial Strains for the Production of Melanins
Table 7.3 Comparison of Engineered Microbial Strains for the Production of Melanins

Chapter 9: Diversity and Applications of Versatile Pigments Produced by Monascus sp

Table 9.1 Microorganisms Producing Monascus Pigments

Chapter 10: Microbial Pigment Production Utilizing Agro-industrial Waste and Its Applications

Table 10.1 Microorganisms and Inexpensive Substrates Used for Pigment Production
Table 10.2 Health Effects of Synthetic Pigments (Blanc 1998; Durán et al. 2002)
Table 10.3 Biologically Active Pigmented Compound from Bacteria and their Market Potential (Dufossé 2009)
Table 10.4 Price Comparison for the Production of 50 L of Prodigiosin from Serratia Marcescens UTM1 Using a Synthetic Versus an Agricultural-Based Growth Medium (Venil et al. 2013)
Table 10.5 Natural Pigments Produced by Bacteria (Malik et al. 2012)
Table 10.6 Recommended Amounts of Arpink Red in Various Foodstuffs, According to the Codex Alimentarius Commission (Kumar et al. 2015)
Table 10.7 Pigments from Monascus sp. (Kumar et al. 2015)
Table 10.8 Production of Microbial Pigments Utilizing Agro-Industrial Waste (Panesar et al. 2015)

Chapter 11: Microbial Pigments: Potential Functions and Prospects

Table 11.1 Historical Development of Microbial Pigments. Source: Information from Duffosé et al. (2005)
Table 11.2 Functions of Different Microbial Pigments. Source: Based on Information Acquired from Duffosé (2006), Duran et al. (2002), Mapari et al. (2005), Ray and Eakin (1975), Teixeria et al. (2012), and Venil et al. (2013)

Chapter 12: The Microbial World of Biocolor Production

Table 12.1 Pigment-Producing Microorganisms

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Title: Bio-pigmentation and biotechnological implementations / [edited by] Om V. Singh.

Description: Hoboken, NJ : Wiley-Blackwell, 2017. | Includes bibliographical references and index.

Identifiers: LCCN 2017007261 (print) | LCCN 2017008051 (ebook) | ISBN 9781119166146 | ISBN 9781119166177 (Adobe PDF) | ISBN 9781119166184 (ePub)

Subjects: | MESH: Industrial Microbiology | Pigments, Biological | Biotechnology-methods

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List of Contributors

Wan Azlina Ahmad, Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Johor, Malaysia
P. Akilandeswari, Department of Microbiology, Karpagam University (Karpagam Academy of Higher Education), Tamil Nadu, India
Alberto Alcázar, Department of Investigation, Hospital Ramon y Cajal, Madrid, Spain
Claira Arul Aruldass, Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Johor, Malaysia
Di Chen, Henan University of Technology, Zhengzhou, China
Cristina Cid, Microbial Evolution Laboratory, Center for Astrobiology (CSIC-INTA), Torrejón de Ardoz, Spain
Laurent Dufossé, Laboratoire de Chimie des Substances Naturelles et des Sciences des Aliments, ESIROI Agroalimentaire, University of La Réunion, Ile de La Réunion, France
Eva García-López, Microbial Evolution Laboratory, Center for Astrobiology (CSIC-INTA), Torrejón de Ardoz, Spain
Guillermo Gosset, Departamento de Ingeniería Celular y Biocatálisis, Instituto de Biotecnología, National Autonomous University of Mexico, Cuernavaca, Mexico
Roshan Gul, Department of Biotechnology, Maharishi Markandeshwar University, Mullana-Ambala, Haryana, India
Sabine A.E. Heider, GSK Vaccines S.r.I., Siena, Italy
Nadja A. Henke, Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Bielefeld, Germany
Thomas Isbrandt, DTU Bioengineering, Technical University of Denmark, Lyngby, Denmark
Sunil H. Koli, School of Life Sciences, North Maharashtra University, Maharashtra, India; and North Maharashtra Microbial Culture Collection Centre (NMCC), North Maharashtra University, Maharashtra, India
Raman Kumar, Department of Biotechnology, Maharishi Markandeshwar University, Mullana-Ambala (Haryana), India
Thomas Ostenfeld Larsen, DTU Bioengineering, Technical University of Denmark, Lyngby, Denmark
Jennifer Lau, Division of Biological and Health Sciences, University of Pittsburgh, Bradford, PA, USA
Ana María Moreno, Microbial Evolution Laboratory, Center for Astrobiology (CSIC-INTA), Torrejón de Ardoz, Spain
Rosemary C. Nwabuogu, Division of Biological and Health Sciences, University of Pittsburgh, Bradford, PA, USA
Satish V. Patil, School of Life Sciences, North Maharashtra University, Maharashtra, India; and North Maharashtra Microbial Culture Collection Centre (NMCC), North Maharashtra University, Maharashtra, India
Petra Peters-Wendisch, Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Bielefeld, Germany
B.V. Pradeep, Department of Microbiology, Karpagam University (Karpagam Academy of Higher Education), Tamil Nadu, India
Jiancheng Qi, University of Alberta, Edmonton, Canada
Chandrashekhar D. Patil, School of Life Sciences, North Maharashtra University, Maharashtra, India
Anil K. Sharma, Department of Biotechnology, Maharishi Markandeshwar University, Mullana-Ambala (Haryana), India
Om V. Singh, Division of Biological and Health Sciences, University of Pittsburgh, Bradford, PA, USA
Rahul K. Suryawanshi, School of Life Sciences, North Maharashtra University, Maharashtra, India; and North Maharashtra Microbial Culture Collection Centre (NMCC), North Maharashtra University, Maharashtra, India
Gerit Tolborg, DTU Bioengineering, Technical University of Denmark, Lyngby, Denmark
Chidambaram Kulandaisamy Venil, Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Johor, Malaysia
Changlu Wang, Tianjin University of Science and Technology, Tianjin, China
Siyuan Wang, Department of Biological Engineering, Utah State University, Logan, UT, USA
Volker F. Wendisch, Chair of Genetics of Prokaryotes, Faculty of Biology & CeBiTec, Bielefeld University, Bielefeld, Germany
Mhairi Workman, DTU Bioengineering, Technical University of Denmark, Lyngby, Denmark
Fuchao Xu, Department of Biological Engineering, Utah State University, Logan, UT, USA
Nur Zulaikha Binti Yusof, Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Johor, Malaysia
Jixun Zhan, Department of Biological Engineering, Utah State University, Logan, UT, USA

Introduction

Biological pigments are naturally occurring chemical compounds that impart certain colors. They serve a variety of functional purposes, such as absorbing ultraviolet (UV) light in order to promote photosynthesis, desorbing certain UV wavelengths to protect organisms from photo damage, and attracting organisms in order to promote mating or pollination. Color-based evaluation is essential, as it indicates fertility, nutritional value, flavor, toxicity, and food spoilage. Human society has incorporated knowledge of our instinctive color perceptions into marketing in order to increase the appeal of food items, pharmaceuticals, and cosmetics.

Artificial food colors and synthetic and natural pigments are used as color additives to augment or correct imperfections in a food's natural color, indicate artificially flavored foods and medicines, or enhance a food's visual appeal. Color additives are used to provide color to foods whose natural color would potentially degrade during shipment and storage when exposed to UV light and extreme changes in temperature and humidity. In these cases, artificial color additives whose chemical structures are stable and do not degrade under various conditions may be preferable for marketing purposes. The US Food and Drug Administration (FDA), under the Food, Drugs and Cosmetics (FD&C) Act, Title 21 of the Code of Federal Regulations (21 CFR 170.3 and 21 CFR 170.30), has approved color additives in food as “GRAS” (Generally Recognized as Safe). The “safe” amount of an artificial color is known as the acceptable daily intake (ADI), measured in parts per million (ppm), that industries are legally permitted to use in products. However, if organisms, specifically humans and animals, cannot metabolize artificial chemical compounds, then how much of a dose is considered “safe” for consumption remains questionable.

The quandary lies directly in the advantage provided by chemically stable compounds. Naturally occurring pigments are biological derivatives of organic compounds that can be metabolically or chemically broken down because they serve to synchronize with organismal demands. Artificial chemical colors, on the other hand, are derivatives of coal tar and petroleum, which cannot be degraded completely. Therefore, artificial pigments are potentially perilous to life because such chemical behaviors are asynchronous with biological function. Studies have shown that various artificial food colors are being linked to biological and neurological effects, such as attention deficit hyperactivity disorder (ADHD) in children and cancer.

Synthesizing bio-pigments through unique microbial metabolic pathways could be the most appropriate way to develop safe natural pigments for industrial use. Understanding the genetic sequences for the biosynthetic metabolites provides further insight into how genes can be manipulated in microorganisms in order to obtain higher yields of specific biological pigments. The broader impact of producing bio-pigments from microorganisms will affect food science, pharmacology, and biomedical practices.

This book aims to bridge the technology gap and focuses on exploring microbial diversity and the various mechanisms regulating the biosynthesis of bio-pigments. Chapter 1 (Wang et al.) presents a variety of microbial pigments from eukaryotic and prokaryotic sources and discusses their properties and applications. Based on the demand of consumers for natural food colorants, Tolborg et al. in Chapter 2 discuss novel cell factories producing natural pigments in Europe. Due to their extraordinary properties, certain organisms, called “extremophiles” (mostly bacteria and archaea, and a few eukaryotes), can thrive under harsh environmental conditions. Garcia-Lopez et al. in Chapter 3 summarize our current understanding of pigments from microbial extremophiles and their potential applications in biotechnology.

Commercial processes for carotenoid production are already being employed. Microorganisms, particularly filamentous fungi, seem to be promising producers of biosynthesized pigments, due to their chemical and color versatility and stability. In Chapter 4, Dufossé presents the facts on current carotenoid production using various microorganisms. In continuation, Heider et al. in Chapter 5 note that the commercial value of carotenoids was reported as $1.5 billion in 2014 and discuss the use of biosynthesis, glycosylation, and metabolic engineering to meet the demand.

Carotenoids are classified by number of isoprene units. In Chapter 6, Nwabuogu et al. predominantly focus on the biosynthesis of β-carotene and its derivative pigments. They also present the native bacterial and fungal species responsible for the biosynthesis of these pigments, along with the molecular elements that regulate β-carotene biosynthesis and fermentation strategies around commercialization.

Among nontraditional pigments, melanin constitutes a diverse group of pigments present in most biological groups. Melanin production is dependent mainly on the activity of enzymes from the tyrosinase and laccase protein families. Gosset, in Chapter 7, presents the advances made in melanin production from microorganisms toward process development.

Monascus pigments, derived from the genus Monascus, are promising as additional or alternative natural food pigments. Wang et al. in Chapter 8 discuss the biochemistry and molecular mechanisms of Monascus pigments. In continuation, Koli et al. in Chapter 9 discuss the diversity and applications of versatile pigments produced by Monascus sp.

Agro-industrial wastes (e.g., livestock waste, manure, crop residue, food waste, molasses, etc.) are high-impact feedstocks with particular utility in the production of pigments. In Chapter 10, Venil et al. discuss the impact of agro-industrial waste and its application in microbial pigment production. In continuation, in Chapter 11, Akilandeswari and Pradeep explore the potential functions of and prospects for microbial pigments. Finally, Gul et al. in Chapter 12 summarize the use of microorganisms in biocolor production.

This book, Bio-pigmentation and Biotechnological Implementations, is a collection of outstanding articles elucidating several broad-ranging areas of progress and challenge in the utilization of microorganisms as sustainable resources in bio-pigmentation. It will contribute to research efforts in the scientific community and to commercially significant work for corporate businesses. The aim is to establish long-term safe and sustainable forms of biopigments through microbial biosynthesis, with minimum impact on the ecosystem.

We hope readers will find these chapters interesting and informative for their research pursuits. It has been my pleasure to put together this book with Wiley-Blackwell. I would like to thank all of the contributing authors for sharing their quality research and ideas with the scientific community through this work.