ABSTRACT
In a variety of organisms, quorum sensing plays a crucial part in controlling microbial communication and, consequently, gene expression. The purpose of this chapter is to evaluate current knowledge of the function of microbial communication in harsh conditions, although this phenomenon has been thoroughly researched in relation to, for instance, virulence gene regulation. Numerous critical microbial functions are regulated by cell signaling, which may be crucial in promoting microbial functional diversity and, ultimately, ecosystem function under harsh settings. The characterization of cell-signaling systems in these communities may offer special insights into understanding the microbial interactions involved in functioning and surviving in harsh environments, according to several recent studies that have examined cell signaling in contemporary analogues to early Earth microbial mats (communities). A key process known as cell signaling may have evolved on the early Earth alongside human populations and the environment. Without cell signaling, selective forces might have led to the extinction of some microbial populations rather than their evolution. Understanding how and why particular microbial functional groups are found in places where they theoretically should not be expected to survive is one of the largest issues in extremophile biology, and carefully controlled communication may be essential. Finally, quorum sensing has just been discovered in archaea for the first time, suggesting that communication at several levels may be essential in harsh settings.
