Cyanobacterial diversity: molecular insights under multifarious environmental conditions

Abstract Cyanobacteria are the first oxygenic photoautotrophs, which are widely distributed in aquatic and terrestrial environments, including extreme habitats such as deserts, hot springs, and polar regions. This chapter presents an overview of recent advancements in cyanobacterial diversity using molecular techniques under various environmental conditions, for example, stromatolites, marine, and freshwater, dry valleys, rice fields, natural and artificial microbial mats, and hot and cold springs. The molecular techniques applied for cyanobacterial diversity assessment range from specific gene (16S ribosomal RNA, nif, rpo, its, etc.)-based PCR, sequencing, and phylogeny, denaturing gradient gel electrophoresis, microarray to metagenomics. It is pertinent to mention here that, nowadays, the polyphasic approach is considered as an indispensable method to register the overall existence of cyanobacteria that a single method is not sufficient to highlight. Microarray and metagenomics may positively contribute in deciphering and amplifying the horizon of cyanobacterial diversity in various natural milieus.