Preface

This book highlights significant advances in the field of cyanobacteria.

Chapter 1 focuses on picocyanobacteria in surface water bodies, while Chapter 2 discusses the removal of microcystins from drinking water by electrocoagulation. Chapter 3 looks at cyanobacteria as a source of antioxidants, and Chapter 4 explores the role of cyanobacteria as an effective tool in sustainable agriculture. In Chapter 5 cyanobacteria as a source of biodegradable plastics is considered, and Chapter 6 explains the thermochemical conversion of algal-based biofuel. Chapter 7 describes the green synthesis of silver nanoparticles from cyanobacteria and Chapter 8 discusses the potential of cyanobacteria natural products for antibiotic drug discovery.

I hope the book will be useful to researchers, academics and students across the world. I am grateful to all the authors for their valuable contributions and to IntechOpen, especially Author Service Manager Ms. Martina Scerbe for her patience and support. Heartfelt thanks to my angels Aarushi and Anviti for their unconditional support and to my mother Ms Vidya Pandey for encouraging me to work hard and always chase dreams.

This book is dedicated to my father in heaven.

**Archana Tiwari** Professor, Amity Institute of Biotechnology, Amity University Noida, India

**1**

**1. Introduction**

**Chapter 1**

Bodies

**Abstract**

Picocyanobacteria in Surface Water

*María Alejandra Pérez Gutiérrez, Luisa María Munera Porras* 

Cyanobacterial harmful algal blooms (CyanoHABs) in lentic, low tidal water bodies with high concentrations of easily assimilated nutrients have generated worldwide concern. However, CyanoHABs often formed from a variety of lesser-known taxa, such as nanocyanobacteria and picocyanobacteria, which are characterized as

numerous and ubiquitous in diverse environments. Studies indicate that some taxa of picocyanobacteria can produce toxins. However, their identification through conventional methods is limited by their size and physiological plasticity, recently molecular methods have been chosen for more reliable results. This systematic review aims to summarize the results of original research articles on predominant picocyanobacteria in surface water bodies collected in indexed journal articles and gray literature. The methodology used consisted of searching for original publications in 3 specific databases and one general, using thesauri and free terms; the articles were filtered by previously defined inclusion and exclusion criteria. Thirty-four articles were selected and analyzed. The results show that the predominant picocyanobacteria in freshwater systems belong to the genus *Synechococcus*, reported in oligotrophic systems and capable of producing cyanotoxins. Likewise, from 2015 to 2019, the largest number of publications on this topic was obtained, mainly in countries such as China and the

**Keywords:** cyanobacteria, cyanoHAB, freshwater, picocyanobacteria, surface water

In recent years, the excessive growth of phytoplanktonic organisms in reservoirs, lagoons, and in general, in lentic, low-tide water bodies with a high concentration of phosphate and nitrogenous nutrients, which are easily assimilated, has generated worldwide concern [1, 2]. Physical factors such as temperature, solar radiation, wind, rain, water column stratification, water flow, or biological interactions with other organisms, among others, play an important role in the so-called cyanobacterial

*Alejandra Sandoval Valencia, Lisseth Dahiana Salas,* 

*and Leonardo Alberto Ríos-Osorio*

United States, which invest in research resources.

harmful blooms (CyanoHAB) [3, 4].

**Chapter 1**
