About this Research Topic
Given the success of Volume I of this Research Topic, and the rapidly evolving subject area, we are pleased to announce the launch of Volume II: Microbial Life Under Stress: Biochemical, Genomic, Transcriptomic, Proteomic, Bioinformatics, Evolutionary Aspects and Biotechnological Applications of Poly-Extremophilic Bacteria.
From its very beginning, life has flourished in almost all imaginable environments, a number of them encompassing truly harsh physical and chemical conditions that once were thought to preclude the existence of living organisms. In this line, the term "extremophile" - from the Latin "extremus" for extreme and the Greek "philos" for love - refers to those organisms, belonging to all domains of life (Archaea, Bacteria and Eukarya), in which unique physiologies are present to cope with the challenges posed by extreme habitats. These include extreme pH values and temperatures, high salinity and pressure, desiccation, low nutrient availability, high UV radiation and even the presence of toxicants such as metal(loid)s that can poison the cell metabolism, among others. It is worth noting that a number of these harsh conditions may apply at once so that bacteria able to withstand them are known as polyextremophiles.
Regardless of the growth conditions, all polyextremophiles were selected for survival in a great variety of niches, thus ensuring such an evolutionary success that results in an extraordinary diversity of microorganisms. In particular, if water is really essential for life, then a number of physical limitations for it to take place are apparent. Water remains liquid within certain limits of temperature and pressure so that organisms living at extreme temperatures (< 0°C and > 100°C) are represented mainly by Archaea and Bacteria.
Since their discovery, research on extremophiles has gained strength, not only because of the interest in defining their lifestyle, physiology and adaptation to hostile environments, but also for exploring their biotechnological potentials and even identify bacterial model systems for life in other planets (astro- or exo-microbiology).
Although many species from all kind of extreme environments have been isolated and taxonomically described, very little is known about the molecular strategies that allow them to grow in these conditions. Here we propose an Interdisciplinary Research Topic that aims to address this issue by using multidisciplinary approaches for integrating data from biochemical, genomic, transcriptomic, proteomic, bioinformatics and evolutionary aspects of polyextremophilic Archaea and Bacteria. Finally, the various and unique physiologies that have evolved to meet the challenges posed by the above described harsh conditions, strongly suggest that life could exist in outer space.
In Memory of Dr. Claudio Vásquez Guzmán;
On behalf of the co-editors Claudia Saavedra, Gloria Levican, and Martina Cappelletti, in relaunching this special topic on Microbial Life Under Stress, I would like to dedicate a few lines to a personal memory of my friend and colleague Claudio Vasquez who died prematurely in July 2020. The events of our scientific life made us meet, and only for a week or so, after many years during which we have been actively discussing issues related to the microbiology of metalloids. We have often found ourselves in disagreement but this did not mean that Claudio gave up inviting me and my wife Michela to visit Chile in 2015. This allowed us to spend wonderful days with him, guiding us and introducing us to the past and recent history of Chile. Claudio proved to be a generous, authentic, outgoing, lively man, a lover of life and good food, and, last but not least, a scientist who raised a group of excellent young researchers in his laboratory in Santiago. My biggest regret is not having been able to host him in Italy, but he will certainly remain in my thoughts for years to come.
Davide Zannoni
Bologna 17 April, 2021
From its very beginning, life has flourished in almost all imaginable environments, a number of them encompassing truly harsh physical and chemical conditions that once were thought to preclude the existence of living organisms. In this line, the term "extremophile" - from the Latin "extremus" for extreme and the Greek "philos" for love - refers to those organisms, belonging to all domains of life (Archaea, Bacteria and Eukarya), in which unique physiologies are present to cope with the challenges posed by extreme habitats. These include extreme pH values and temperatures, high salinity and pressure, desiccation, low nutrient availability, high UV radiation and even the presence of toxicants such as metal(loid)s that can poison the cell metabolism, among others. It is worth noting that a number of these harsh conditions may apply at once so that bacteria able to withstand them are known as polyextremophiles.
Regardless of the growth conditions, all polyextremophiles were selected for survival in a great variety of niches, thus ensuring such an evolutionary success that results in an extraordinary diversity of microorganisms. In particular, if water is really essential for life, then a number of physical limitations for it to take place are apparent. Water remains liquid within certain limits of temperature and pressure so that organisms living at extreme temperatures (< 0°C and > 100°C) are represented mainly by Archaea and Bacteria.
Since their discovery, research on extremophiles has gained strength, not only because of the interest in defining their lifestyle, physiology and adaptation to hostile environments, but also for exploring their biotechnological potentials and even identify bacterial model systems for life in other planets (astro- or exo-microbiology).
Although many species from all kind of extreme environments have been isolated and taxonomically described, very little is known about the molecular strategies that allow them to grow in these conditions. Here we propose an Interdisciplinary Research Topic that aims to address this issue by using multidisciplinary approaches for integrating data from biochemical, genomic, transcriptomic, proteomic, bioinformatics and evolutionary aspects of polyextremophilic Archaea and Bacteria. Finally, the various and unique physiologies that have evolved to meet the challenges posed by the above described harsh conditions, strongly suggest that life could exist in outer space.
In Memory of Dr. Claudio Vásquez Guzmán;
On behalf of the co-editors Claudia Saavedra, Gloria Levican, and Martina Cappelletti, in relaunching this special topic on Microbial Life Under Stress, I would like to dedicate a few lines to a personal memory of my friend and colleague Claudio Vasquez who died prematurely in July 2020. The events of our scientific life made us meet, and only for a week or so, after many years during which we have been actively discussing issues related to the microbiology of metalloids. We have often found ourselves in disagreement but this did not mean that Claudio gave up inviting me and my wife Michela to visit Chile in 2015. This allowed us to spend wonderful days with him, guiding us and introducing us to the past and recent history of Chile. Claudio proved to be a generous, authentic, outgoing, lively man, a lover of life and good food, and, last but not least, a scientist who raised a group of excellent young researchers in his laboratory in Santiago. My biggest regret is not having been able to host him in Italy, but he will certainly remain in my thoughts for years to come.
Davide Zannoni
Bologna 17 April, 2021
Keywords: Extremophiles, Environmental stress, molecular mechanisms, adaptive evolution, resistance.
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