Preface

Cyanobacteria are an interesting group of bacteria for their unique characteristics and potential biotechnological applications. They are very important for life on Earth because they are oxygenic organisms that also play crucial roles in the cycles of carbon, nitrogen, and oxygen. Interestingly, they have unique specialized cells called heterocysts for nitrogen fixation. Therefore, they are ideal model organisms for studying photosynthesis, nitrogen fixation, and other biological processes. In addition, cyanobacteria are well recognized for their potential for a variety of biotechnological applications. They were reported to produce a wide array of biologically active compounds that are attracting interest from the pharmaceutical industry for drug development. Also, they have various applications in agriculture as potential biofertilizers or in the industry for biofuel production, in addition to many other biotechnological applications.

Due to the increasing interest in this group of microorganisms, this book discusses recent advances in taxonomy and applications of cyanobacteria. It is a useful resource for students starting their research work on cyanobacteria, researchers interested in the recent advancements in their research field, and teachers involved in teaching topics related to cyanobacteria. The book contains five chapters.

Chapter 1 discusses the molecular methods applied for identifying freshwater toxigenic cyanobacteria, reviewing recent methods to rapidly and accurately identify toxic cyanobacteria, which is difficult due to the lack of discernable morphological difference between toxic and non-toxic strains within the same cyanobacterial species or genus. This information is important for students and researchers to understand the methods they are going to use in their research.

Chapter 2 outlines the diverse industrial applications of cyanobacteria in the pharmaceutical, agricultural, and health sectors. The applications include the production of bioplastics, biofuels, biofertilizers, foods, nutraceuticals, and pharmaceuticals. Additionally, the metabolic pathways that lead to the production of some important cyanobacterial bioactive compounds are outlined in this chapter along with examples of the commercial products from cyanobacteria currently available on the market.

Chapter 3 reviews the potential of cyanobacteria in wound healing. It is clearly shown that these organisms have immense potential to be utilized for the development of bioactive wound dressings.

Chapter 4 introduces a very interesting and special application for *Synechocystis* sp. PCC 6803, which is the production of a novel hemoglobin. The chapter sheds light on the structure–function relationship and potential applications of this novel hemoglobin. It has been reported that cyanobacterial hemoglobins have displayed unprecedented stability, unique heme coordination, and other properties that are not often observed in the globin superfamily. Therefore, this chapter provides an overview of the unique globin from *Synechocystis* sp. PCC 6803 and its biotechnological implications, including potential in the field of artificial oxygen carriers.

Chapter 5 highlights the diversity, distribution, and applications of cyanobacteria in the Brazilian coastline in order to fill a gap in cyanoflora knowledge. Recognition of the Brazilian cyanoflora contributes to the understanding of the functioning and monitoring of marine ecosystems and provides data for the construction of future public policies.

I would like to thank all the contributors for sharing their excellent research work and for their academic integrity. I would also like to thank the staff at IntechOpen, particularly Author Service Manager Ms. Sara Debeuc for her commitment, patience, and keen assistance in making this book possible.

Finally, I hope that readers will find this book interesting and use the information contained herein to positively contribute to the research community.

> **Wael N. Hozzein** Botany and Microbiology Department, Faculty of Science, Beni-Suef University, Beni-Suef, Egypt

#### **Chapter 1**
