Preface

I am pleased to introduce the book "Microalgae - From Physiology to Application" published by IntechOpen publisher. The book summarizes current reviews and original articles on microalgae. The term microalgae is commonly used to describe microscopic algae and cyanobacteria. It is thus a very diverse group of photosynthetic microorganisms living in a variety of environments including extreme habitats. Not only are these organisms fascinating, they can also be exploited by humans for biotechnologies. Except for the variety of applications, this book aims to address at least some aspects of microalgae physiology, as applications in biotechnology cannot be successful without a solid knowledge of physiology.

The book is organized into four sections and twelve chapters. The sections *Phytoplankton, Microalgae as a nutrition, Microalgae applications,* and *Microalgae secondary metabolites* are not strictly defined and the topics partly overlap, reflecting the complexity of the topic.

The first section *Phytoplankton* presents Chapter 1, which describes the potential of a novel fluorescent spectroscopic technique for a microalgae species discrimination. The method is based on special data processing of a set of fluorescent spectra, obtained from a single photosynthetic cell of cyanobacteria. The universality of the considered technique makes it possible to use for investigation of any phytoplankton species irrespective of their habitat or cultivation. The automatization of the cyanobacterial species differentiation is a key problem in both industrial biomass production and environmental monitoring.

Chapter 2 discusses the eutrophication of inland waters in many countries from North to South America due to the increase of the internal load of nitrogen and phosphorus. As a consequence, the phytoplankton community in freshwater lakes and reservoirs is mainly dominated by Cyanobacteria. The taxonomic groups of phytoplankton can be used to indicate the trophic level and water quality status of freshwater systems.

Chapter 3 is a very nice tutorial summarizing various techniques and laboratory protocols of the isolation of native microalgae and their characterization standardized by the authors. The biotechnological potential (biodiesel and nutraceuticals production) of the native microalgae isolated from Peruvian Amazon is evaluated. The isolation and culture techniques of native microalgae, culture media, growth evaluation process and techniques for molecular characterization are listed and described in detail.

The second section *Microalgae as a nutrition* includes Chapter 4, which reviews the effect of traditional and innovative drying methods on quality and stability of microalgae biomass powders with potential use in human alimentation. Microalgae are dried to allow easy storage and transportation as well as to facilitate their use in biorefinery and the food and feed industry. The understanding of the degradative phenomena that occur during storage, namely high sensitivity to light, heat and oxygen, of dried microalgal biomass is important.

**II**

**Chapter 7 123**

**Chapter 8 145**

**Chapter 9 157**

**Chapter 10 171**

Microalgae Secondary Metabolites **191**

**Chapter 11 193**

**Chapter 12 211**

*by Facundo J. Márquez-Rocha, Diana Palma-Ramírez, Pedro García-Alamilla, Jenny F. López-Hernández, Ivonne S. Santiago-Morales and Abelardo I. Flores-Vela*

*by Maiara Priscilla de Souza, Andrea Sanchez-Barrios, Tiele Medianeira Rizzetti, Lisianne Brittes Benitez, Michele Hoeltz, Rosana de Cassia de Souza Schneider* 

The Colonial Microalgae *Botryococcus braunii* as Biorefinery *by Edmundo Lozoya-Gloria, Xochitl Morales-de la Cruz* 

Bioconcentration of Marine Algae Using Lipase Enzyme

Concepts and Trends for Extraction and Application of Microalgae

Changes in Photochemical Efficiency and Differential Induction of Superoxide Dismutase in Response to Combined Stresses of Chilling Temperature and Relatively High Irradiation in Two *Chlorella* Strains

Microalgae Cultivation for Secondary Metabolite Production

*by Manoj Kamalanathan and Antonietta Quigg*

Physiological Limitations and Solutions to Various Applications of

*and Takehiro A. Ozawa-Uyeda*

*by Jithu Paul Jacob*

Carbohydrates

**Section 4**

Microalgae

*and Fábio de Farias Neves*

*by Lee-Feng Chien and Wen-Hao Lin*

Chapter 5 deals with the use of microalgae as food supplements. The diversity of microalgae, their components, applications, and potential health benefits are discussed. The major economically important species like *Spirulina, Chlorella, Dunaliella, Haematococcus,* and *Aphanizomenon* are described in detail in single subchapters.

The third section *Microalgae applications* forms the biggest part of the book and deals with the exploitation of microalgae in biotechnology.

Chapter 6 introduces the unicellular red alga *Galdieria* of the class Cyanidiophyceae. The authors review the origin and taxonomy of *Galdieria* as well as its morphology, genome, and unique extremophilic features. The algae can grow in extreme conditions like high acidity, very low pH, or extremely high metal concentrations. It also exhibits a broad metabolic flexibility to grow photoautotrophically, heterotrophically, or mixotrophically, and to utilize a whole range of unusual carbon sources. This chapter also focuses on applications in biotechnology. Wastewater treatment, selective metal precipitation, or scarce metals recovery from secondary sources is discussed.

In Chapter 7, the authors evaluate the potential of microalga *Botryococcus braunii* (Trebouxiophyceae) to be used as a biorefinery organism. The authors clearly describe the physiology and biochemistry of different *Botryococcus braunii* races and summarize all value-added compounds produced by the alga. The profitability of the production of hydrocarbons, lipids, pigments, polysaccharides, and other polymers is mentioned too.

Chapter 8 deals namely with poly unsaturated fatty acids (PUFAs) production by marine algae and the use of lipases as a tool for their enrichment. Marine algae rich in n-3 PUFA are a natural and readily available resource of PUFA and alternative to fish oil derived n-3 PUFA. The enrichment of microalgae using biolipase from the yeast *Candida cylinderacea* source is of particular interest. The analysis of fatty acids in marine algae and the PUFA application effects are explained.

In Chapter 9, the authors explain the composition of carbohydrates in microalgae biomass, focusing on separation methods, chemistry and molecular characterization as well as their application in several areas. Steps for extraction and purification are discussed as well as the relationship between the type of microalgae and its composition. The current and prospective trends and methodologies for the use of microalgae carbohydrates are summarized.

Chapter 10 is an original research article dealing with adaptation of two *Chlorella* strains to chilling temperature and irradiance. *Chlorella* is used for large-scale outdoor production in Taiwan so the understanding of how green algae overcome chilling temperatures during winter is useful from a biotechnological point of view. The authors studied changes in photochemical efficiency and differential induction of superoxide dismutase as a response to the combined stresses of chilling temperature and high irradiation.

The last section, *Microalgae secondary metabolites*, is devoted to the cultivation of microalgae for the production of a variety of secondary metabolites for possible commercialization.

**V**

Chapter 11 describes the cultivation of microalgae for secondary metabolite production. The authors describe in detail the metabolism of microalgae and the kinetics of mixotrophic growth. The comparison of open and closed photobioreactors is introduced and the problematics discussed. The topic of scale up production of microalgae is mentioned. The secondary metabolites like fine chemicals, pigments, antioxidants, lipids, and proteins are listed and the microalgae and the conditions

The closing chapter, Chapter 12, is an excellent review of various applications of microalgae. The authors focus on the physiological limitations behind the synthesis of microalgal products, highlight the crucial unknowns behind the role and synthesis of these products and hint at strategies to overcome the limitations to realize the

As the editor, I am happy to present to the readers such a broad collection of topics by a large number of experts from the field of microalgae research. Both authors

I thank all the contributors for their effort and Ms. Lada Bozic, Author Service

**Prof. (FH) RNDr. Milada Vítová, PhD**. Laboratory of Cell Cycles of Algae,

Institute of Microbiology of the Czech Academy of Sciences,

Centre Algatech,

Czech Republic

suitable for their production are listed.

commercial dream of microalgal products.

and readers can enjoy the open access to all chapters.

Manager, for the smooth cooperation and help.

Welcome to the amazing world of microalgae!

Chapter 11 describes the cultivation of microalgae for secondary metabolite production. The authors describe in detail the metabolism of microalgae and the kinetics of mixotrophic growth. The comparison of open and closed photobioreactors is introduced and the problematics discussed. The topic of scale up production of microalgae is mentioned. The secondary metabolites like fine chemicals, pigments, antioxidants, lipids, and proteins are listed and the microalgae and the conditions suitable for their production are listed.

The closing chapter, Chapter 12, is an excellent review of various applications of microalgae. The authors focus on the physiological limitations behind the synthesis of microalgal products, highlight the crucial unknowns behind the role and synthesis of these products and hint at strategies to overcome the limitations to realize the commercial dream of microalgal products.

As the editor, I am happy to present to the readers such a broad collection of topics by a large number of experts from the field of microalgae research. Both authors and readers can enjoy the open access to all chapters.

I thank all the contributors for their effort and Ms. Lada Bozic, Author Service Manager, for the smooth cooperation and help.

Welcome to the amazing world of microalgae!

**Prof. (FH) RNDr. Milada Vítová, PhD**. Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Czech Republic

**IV**

subchapters.

discussed.

polymers is mentioned too.

ture and high irradiation.

commercialization.

Chapter 5 deals with the use of microalgae as food supplements. The diversity of microalgae, their components, applications, and potential health benefits are discussed. The major economically important species like *Spirulina, Chlorella, Dunaliella, Haematococcus,* and *Aphanizomenon* are described in detail in single

The third section *Microalgae applications* forms the biggest part of the book and

In Chapter 7, the authors evaluate the potential of microalga *Botryococcus braunii* (Trebouxiophyceae) to be used as a biorefinery organism. The authors clearly describe the physiology and biochemistry of different *Botryococcus braunii* races and summarize all value-added compounds produced by the alga. The profitability of the production of hydrocarbons, lipids, pigments, polysaccharides, and other

Chapter 8 deals namely with poly unsaturated fatty acids (PUFAs) production by marine algae and the use of lipases as a tool for their enrichment. Marine algae rich in n-3 PUFA are a natural and readily available resource of PUFA and alternative to fish oil derived n-3 PUFA. The enrichment of microalgae using biolipase from the yeast *Candida cylinderacea* source is of particular interest. The analysis of fatty acids

In Chapter 9, the authors explain the composition of carbohydrates in microalgae biomass, focusing on separation methods, chemistry and molecular characterization as well as their application in several areas. Steps for extraction and purification are discussed as well as the relationship between the type of microalgae and its composition. The current and prospective trends and methodologies for the use of

Chapter 10 is an original research article dealing with adaptation of two *Chlorella* strains to chilling temperature and irradiance. *Chlorella* is used for large-scale outdoor production in Taiwan so the understanding of how green algae overcome chilling temperatures during winter is useful from a biotechnological point of view. The authors studied changes in photochemical efficiency and differential induction of superoxide dismutase as a response to the combined stresses of chilling tempera-

The last section, *Microalgae secondary metabolites*, is devoted to the cultivation of microalgae for the production of a variety of secondary metabolites for possible

in marine algae and the PUFA application effects are explained.

microalgae carbohydrates are summarized.

Chapter 6 introduces the unicellular red alga *Galdieria* of the class Cyanidiophyceae. The authors review the origin and taxonomy of *Galdieria* as well as its morphology, genome, and unique extremophilic features. The algae can grow in extreme conditions like high acidity, very low pH, or extremely high metal concentrations. It also exhibits a broad metabolic flexibility to grow photoautotrophically, heterotrophically, or mixotrophically, and to utilize a whole range of unusual carbon sources. This chapter also focuses on applications in biotechnology. Wastewater treatment, selective metal precipitation, or scarce metals recovery from secondary sources is

deals with the exploitation of microalgae in biotechnology.

**1**

Section 1

Phytoplankton
