Challenges of unculturable bacteria: environmental perspectives

TLDR

Environmental biotechnology offers promising techniques for rehabilitating polluted environments, yet success hinges on indigenous microbial communities, many of which remain uncultivated, underscoring the need to investigate their intrinsic functions. This review aims to provide a comprehensive overview of viable but nonculturable and yet‑to‑be‑cultivated bacteria, their awakening strategies, isolation trends, and potential roles in environmental rehabilitation. The authors synthesize information on the presence of these hidden bacterial populations, their awakening mechanisms via extracellular metabolites, current isolation approaches, and prospective applications in bioremediation.

Abstract

Abstract Environmental biotechnology offers several promising techniques for the rehabilitation of polluted environments. The modern industrialized world presents novel challenges to the environmental sciences, requiring a constant development and deepening of knowledge to enable the characterization of novel pollutants and a better understanding of the bioremediation strategies as well as their limiting factors. The success of bioremediation depends heavily on the survival and activities of indigenous microbial communities and their interaction with introduced microorganisms. The majority of natural microbiomes remain uncultivated; therefore, further investigations focusing on their intrinsic functions in ecosystems are needed. In this review, we aimed to provide (a) a comprehensive overview of the presence of viable but nonculturable bacteria and yet-to-be-cultivated cells in nature and their diverse awakening strategies in response to, among other factors, signalling extracellular metabolites (autoinducers, resuscitation promoting factors, and siderophores); (b) an outline of the trends in isolating unculturable bacteria; and (c) the potential applications of these hidden players in rehabilitation processes.