Editorial: Microbial Ecology and Biotechnological Potential of Alkaline Environments

Anne Postec¹Isao Yumoto^2*Liliana Morales-Barrera³Amare Gessesse⁴Duncan G. G. McMillan⁵

• ¹Aix-Marseille Universite, Marseille, France
• ²Osaka University, Suita, Japan
• ³Instituto Politecnico Nacional, Mexico City, Mexico
• ⁴Botswana Institute for Technology Research and Innovation, Gaborone, Botswana
• ⁵University of Read, Whiteknights, United Kingdom

disproportionation; ATP synthesis; respiratory chain, biogeography; sustainable biotechnology; phycocyanin production; circular bioeconomy Alkaliphilic microorganisms can thrive in extraordinarily diverse ecosystems, such as microniches in seemingly ordinary environments, as well as large areas that can be saturated with salts. Indeed, they can exist in ordinary garden soil, indicating the presence of small alkaline niches within conventional environments (Horikoshi, 2004). At the same time, soda lakes representing vast and permanently alkaline ecosystems, characterized by stable high pH and carbonate buffering, and also are home to specialized haloalkaliphilic communities (Sorokin et al., 2014).Alkaliphiles have evolved unique adaptations that allow them to thrive under conditions of low proton availability, high ionic stress, and limited access to nutrients and trace metals. Despite these physicochemical constraints, alkaline soda lakes rank among the most biologically productive ecosystems on Earth, exhibiting vigorous microbial element cycling and dense phototrophic populations (Haines et al., 2023).Individual alkaliphilic cells are capable of sustaining entire ecosystems and often exhibit rapid growth. This apparent paradox underscores the extraordinary adaptive potential of alkaliphiles, which have evolved not only to endure harsh conditions, but have harnessed them as key drivers of metabolic innovation. In many cases, environmental constraints become catalytic forces for the development of unique bioenergetic strategies and biosynthetic capabilities.Because enzymes derived from alkaliphiles exhibit high activity at ambient temperatures and remarkable stability under various conditions, their proteins have long been applied in industrial contexts, such as laundry detergents and food production. Such enzymes include proteases, amylases, and cyclodextrin-producing enzymes (Horikoshi, 2004).Taken together, these observations suggest that alkaline ecosystems, and the multifactorially adapted microorganisms within them, have emerged as reservoirs of novel enzymes, metabolites, and bioenergetic strategies with promising applications in biotechnology, bioremediation, and sustainable manufacturing. This Research Topic brings together recent advances in the study of microbial diversity, metabolic innovation, and ecological function in alkaline environments. The contributions span a wide range of approaches, from metagenomics and transcriptomics to culture-based isolation and biochemical characterization offering a multidimensional view of how life persists and flourishes under alkaline environments. Three major themes emerge from this collection, reflecting the multidimensional nature of microbial life in alkaline environments. Contributions to this research topic highlight how alkaline ecosystems host complex microbial consortia shaped by environmental gradients, dispersal barriers, and biotic interactions.In Soap Lake (Washington, USA), Vanderlaan et al. combined culture-based and 16S rRNA amplicon sequencing approaches to characterize microbial diversity across oxic and anoxic layers. They isolated over 100 alkaliphilic strains, including cold-adapted Vibrio, and identified sulfate-reducing Deltaproteobacteria in deep waters. Ren and Wang conducted a global biogeographic survey of soda lake microbiomes using 51 metagenomes from Africa, Asia, and North America. Their analysis revealed strong distance-decay relationships in taxonomic and functional composition, and uneven cross-continent transition rates, highlighting dispersal limitation and regional endemism. Wang et al. investigated the effects of microbial communities during the cultivation of three salt-tolerant plants in severely saline-alkaline soils. Their study showed that plant-microbe interactions can improve soil quality, enhance microbial diversity, and influence pathogen dynamics, with chicory showing the strongest positive impact.These studies reveal how microbial communities in alkaline environments are shaped by stratification, geographic isolation, and biotic interactions. They highlight ecological complexity and adaptive resilience. Together, they underscore the role of environmental gradients and biological partnerships in structuring microbial diversity and function under alkaline stress. All together, the articles in this Research Topic expand our understanding of microbial life in alkaline environments, from molecular mechanisms and ecological dynamics to applied innovations. They reveal that alkaliphilic microorganisms are not merely survivors of extreme conditions, but active architects of robust and productive ecosystems.As global interest in sustainable biotechnology and environmental resilience grows, the insights gained from alkaline habitats will be increasingly valuable. Future research may focus on:• Exploring microbial interactions and co-evolution in stratified or plant-associated alkaline environments • Integrating multi-omics approaches to uncover hidden metabolic potential and regulatory networks • Elucidating the structural basis of bioenergetic adaptations in proton-limited systems • Scaling up bioprocesses that leverage alkaliphilic metabolism for industrial and environmental applicationsWe hope this collection inspires further interdisciplinary exploration of alkaline ecosystems and encourages the integration of ecological insight with biotechnological innovation.