Ubiquitous presence of cyanobacteria even under extreme conditions since millions of years is due to their ease in adaptability to these environments through various cellular and molecular modifications. Formation of biofilms has been found to be one of the effective modes of survival under harsh environmental conditions, with exopolysaccharides (EPS) contributing to the formation of these biofilms. Cyanobacterial EPS are unique heteropolysaccharides and being anionic in nature, they have the capabilities for excellent heavy metal adsorption and thus, play a vital role in conferring tolerance against heavy metal toxicity. EPS biosynthesis occurs through multiple pathways involving a multitude of genes. A comprehensive overview on these genes in cyanobacteria using Nostoc sp. strain PCC7120 as the model organism has been discussed in this review. The review also emphasizes on the contribution of EPS to heavy metal remediation and biofilm formation. In the age of developing eco-friendly approaches for environmental clean-up, this information would help engineer cyanobacteria as a potential green technology tool for bioremediation and waste water management.

数百万年来，即使在极端条件下，蓝藻也无处不在，这是由于它们通过各种细胞和分子修饰轻松适应这些环境。已发现生物膜的形成是恶劣环境条件下的有效生存方式之一，胞外多糖 (EPS) 有助于这些生物膜的形成。蓝细菌 EPS 是独特的杂多糖，本质上是阴离子的，它们具有优异的重金属吸附能力，因此在赋予对重金属毒性的耐受性方面起着至关重要的作用。EPS 生物合成通过涉及多种基因的多种途径发生。使用Nostoc对蓝藻中这些基因的全面概述sp. 本综述讨论了菌株 PCC7120 作为模式生物。该评论还强调了 EPS 对重金属修复和生物膜形成的贡献。在开发环境清洁方法的时代，这些信息将有助于将蓝藻设计为生物修复和废水管理的潜在绿色技术工具。