Preface

Cyanobacteria are phototrophs with unmatched potentials and numerous applications in ad‐ dition to the significant ecological roles they contribute in the environment. They have a great evolutionary history with a much eminent role and inhabit almost all geographic locations, including oceans, caves, ponds, lakes, soil, snow, and hot springs. The eutrophication in wa‐ ter bodies triggers the formation of blooms. Cyanotoxins are the toxins secreted by some cya‐ nobacteria and are segregated on the basis of their mode of action into hepatotoxins, neurotoxins, cytotoxins, dermatotoxins, and irritant toxins. They can generate a variety of biofuels—hydrogen, ethanol, butanol, biodiesel, and methane. They find application in reme‐ diation of wastewater and heavy metal eradication in addition to their ability to reclaim soil, enhance the fertility of the soil, promote plant growth, act as biocontrol agents, and so on.

The bioactive compounds from cyanobacteria are quite enormous, and more than 800 com‐ pounds have been documented from marine cyanobacteria. In early 1500 BC, the therapeutic abilities of cyanobacteria were first acknowledged, and the genus *Nostoc* sp. was utilized in the treatment of diseases such as cancer, gout, and fistula. Later on, in 1900, Moore and Ger‐ wick undertook extensive work on elucidating the role and application of cyanobacteria. Elaborative studies are untaken worldwide to unravel the untapped potential of cyanobacte‐ ria in the treatment of cancer, Alzheimer's disease, leishmaniasis, and many bacterial, fun‐ gal, and protozoan diseases. They are rich in antioxidative enzymes, and they find application in cosmeceuticals. The selective cyanobacterial compounds are in final clinical trials, which signify the conspicuous role they can play in the coming decade as substantial precursors of new-age drug molecules.

This book highlights the important aspects pertinent to the unique world of cyanobacteria. This book covers diverse topics and provides insights into the world of tiny microbial facto‐ ries and their unraveled potentials.

#### **Dr Archana Tiwari**

Associate Professor Amity Institute of Biotechnology Amity University Noida, Uttar Pradesh, India

**Section 1**

**The World of Cyanobacteria**
