Editorial: Adaptation of halophilic/halotolerant microorganisms and their applications, volume II

Halophilic and halotolerant microorganisms are uniquely adapted to thrive in high-salt environments 17 such as saline soils, deserts, salt lakes, and certain food products. Their adaptations to extreme 18 conditions garnered significant interest across various fields, including agriculture, medicine, and 19 biotechnology. Recent advancements in the isolation and taxonomic characterization of these 20 microorganisms, along with studies on their metabolic capabilities and the compounds they produce, 21 have greatly expanded our understanding of their diversity and resilience. Besides, exploring microbial 22 diversity of Earth's extreme environments contribute to understanding how life could be possible on 23 other planets. Related to this topic, Runzheimer and colleagues have analysed microbial diversity in 24Zechstein salt deposits located in Germany. peroxidases. This study not only demonstrates functional stratification but also offers new options for 73 biotechnological uses of extreme enzymes. In connection with biotechnological applications of 74 extreme enzymes, Foronda and colleagues made efforts to study the production of lipases by Bacillus 75 safensis VC-6 isolated from the volcanic region of Copahue (Chile). This strain showed higher 76 potential for lipase production compared to other Bacillus species, and those lipases exhibited higher 77 thermostable and halotolerant profiles. Considering the applications of these enzymes, this study was 78 complemented with the optimization of growth conditions and the identification of critical genes 79 related to lipase production to further enhance their production at large scale. Regarding to 80 bioremediation, Wang and coworkers have optimized an adaptive laboratory evolution process 81 aiming at phenol degradation in the presence of high salt concentrations thanks to a co-culture of 82Halomonas mongoliensis and Dunaliella salina. This study demonstrated that the co-culture system 83 could completely degrade 500 mg L -1 of phenol within 8 days, outperforming the original D. salina co-84 culture system. 85 86Finally, the antioxidants, antimicrobial molecules and small peptides showing different biological 87 activities produced by these microorganisms have applications in biomedicine and the food industry, 88 while their compatible solutes are valuable in the cosmetic and pharmaceutical sectors. These solutes 89 not only mitigate desiccation damage and protect proteins under extreme conditions (such as high or 90 low temperatures and oxidative stress), but also regulate gene expression in cells, such as heat shock 91 proteins in keratinocytes. In alignment with these applications, Karthik and colleagues isolated 92Boudabousia marimammalium from mangrove soil located in the Mangalore region of Dakshina 93 Kannada (India), showing the capacity to produce bioactive peptides with dual antimicrobial (against 94 some of the most common bacterial genera causing human diseases) and anticancer properties (tested 95 against PC3 cells, a representative of prostate cancer in human beings). 96 97In summary, advances in knowledge about the molecular adaptations of halotolerant and halophilic 98 microorganisms not only allow us to better understand ecosystem dynamics but also highlight their 99 enormous potential for developing processes that allow us to minimize the impact of environmental 100 pollution and climate change, without forgetting the possibility of designing and developing processes 101 and formulations that integrate their molecules. A clear example of the enormous potential offered by 102 these microorganisms is the significant number of research papers published each year on this topic, 103 because of the social and scientific impact of the results obtained and the investments made worldwide 104 to support research in this field by different agencies. 105