Mining microbial resources from water

In the past two decades, the concept of microbial resources evolved from the conserved strains in culture collection centers and microbial genome data in databases to functional microbial consortia, strains with superior phenotypes, novel biochemical and signaling systems, highly efficient enzymes, secondary metabolites, and unique genetic traits. Natural and engineered water environments provide diverse ecological niches for microorganisms to evolve and thrive, serving as treasure troves of microbial resources. Compared with that of chemical and energy resources from water, mining of microbial resources is severely underexplored. In this review, we first summarize various approaches (e.g., cultivation, functional metagenomics, and single-cell genomics) that have been employed to mine microbial resources from water, and then discuss their distinctive advantages and limitations. Lastly, we explore future directions on the mining of microbial resources from water.