Adaption Of Microbial Life To Environmental Extremes

This entirely updated second edition provides an overview on the biology, ecology and biodiversity of extremophiles. Unusual and less explored ecosystems inhabited by extremophiles such as marine hypersaline deeps, extreme cold, desert sands, and man-made clean rooms for spacecraft assembly are presented. An additional focus is put on the role of these highly specialized microorganism in applied research fields, ranging from biotechnology and nanotechnology to astrobiology. Examples such as novel psychrophilic enzymes, compounds from halophiles, and detection strategies for potential extraterrestrial life forms are discussed in detail. The book addresses researchers and advanced students in the fields of microbiology, microbial ecology and biotechnology.

Today's microorganisms represent the vast majority of biodiversity on Earth and have survived nearly 4 billion years of evolutionary change. However, we still know little about the processes of evolution as applied to microorganisms and microbial populations. Microbial evolution occurred and continues to take place in a vast variety of environmental conditions that range from anoxic to oxic, from hot to cold, from free-living to symbiotic, etc. Some of these physicochemical conditions are considered "extreme", particularly when inhabitants are limited to microorganisms. It is easy to imagine that microbial life in extreme environments is somehow more constrained and perhaps subjected to different evolutionary pressures. But what do we actually know about microbial evolution under extreme conditions and how can we apply that knowledge to other conditions? Appealingly, extreme environments with their relatively limited numbers of inhabitants can serve as good model systems for the study of evolutionary processes. A look at the microbial inhabitants of today's extreme environments provides a snapshot in time of evolution and adaptation to extreme conditions. These adaptations manifest at different levels from established communities and species to genome content and changes in specific genes that result in altered function or gene expression. But as a recent (2011) report from the American Academy of Microbiology observes: "A complex issue in the study of microbial evolution is unraveling the process of evolution from that of adaptation. In many cases, microbes have the capacity to adapt to various environmental changes by changing gene expression or community composition as opposed to having to evolve entirely new capabilities." We have learned much about how microbes are adapted to extreme conditions but relatively little is known about these adaptations evolved. How did the different processes of evolution such as mutation, immigration, horizontal (lateral) gene transfer, recombination, hybridization, genetic drift, fixation, positive and negative selection, and selective screens contribute to the evolution of these genes, genomes, microbial species, communities, and functions? What are typical rates of these processes? How prevalent are each of these processes under different conditions? This book explores the current state of knowledge about microbial evolution under extreme conditions and addresses the following questions: What is known about the processes of microbial evolution (mechanisms, rates, etc.) under extreme conditions? Can this knowledge be applied to other systems and what is the broader relevance? What remains unknown and requires future research? These questions will be addressed from several perspectives including different extreme environments, specific organisms, and specific evolutionary processes.

Extreme Environments: Mechanisms of Microbial Adaptation is a collection of papers presented at the symposium on Extreme Environments: Mechanisms of Microbial Adaptation, held at Ames Research Center, Moffett Field, California in June 1974. The meeting emphasizes research work leading to an understanding of the molecular mechanisms that allow the organism to survive extreme environments. The book presents lectures and papers on the general aspects of microbial adaptation; effects of temperature and high salt concentration on the various steps in information transfer; and on microbial enzymes. Effects of temperature, salt, and pressure on membrane structure and function are analyzed as well. The book will be of interest to biologists, microbiologists, biochemists, zoologists, and students of life sciences.

This book explores microbial lifestyles, biochemical adaptations, and trophic interactions occurring in extreme environments. By summarizing the latest findings in the field it provides a valuable reference for future studies. Spark ideas for biotechnological and commercial exploitation of microbiomes at the extremes of life are presented. Chapters on viruses complement this highly informative book. In a vertical journey through the microbial biosphere it covers aspects of cold environments, hot environments, extreme saline environments, and extreme pressure environments, and more. From the deep sea, through polar deserts, up to the clouds in the air - the diversity of microbial life in all habitats is described, explored, and comprehensively reviewed. Possible biotechnical applications are discussed. This book aims to provide a useful reference for those who want to start a research program in extreme microbiology and, hopefully, inspire new research directions.

In this Journey to Microbial Worlds we present the diversity of microorganisms, from the state of fossil microbes in Archaean age rocks to the possibilities of extraterrestrial life. This volume discusses the extremophiles living in harsh environments (from our anthropocentric point) and describes them in considerable detail. Some chapters also review topics such as symbiosis, bacterial luminescence, methanogens, and petroleum-grown cells. The final chapters of this book shed new light on astrobiology and speculate on extremophiles as candidates for extraterrestrial life. All chapters are updated to the latest research level.

This book provides an intriguing look at how life can adapt to many different extreme environments. It addresses the limits for life development and examines different strategies used by organisms to adapt to different extreme environments.

The cryosphere stands for environments where water appears in a frozen form. It includes permafrost, glaciers, ice sheets, and sea ice and is currently more affected by Global Change than most other regions of the Earth. In the cryosphere, limited water availability and subzero temperatures cause extreme conditions for all kind of life which microorganisms can cope with extremely well. The cryosphere’s microbiota displays an unexpectedly large genetic potential, and taxonomic as well as functional diversity which, however, we still only begin to map. Also, microbial communities influence reaction patterns of the cryosphere towards Global Change. Altered patterns of seasonal temperature fluctuations and precipitation are expected in the Arctic and will affect the microbial turnover of soil organic matter (SOM). Activation of nutrients by thawing and increased active layer thickness as well as erosion renders nutrient stocks accessible to microbial activities. Also, glacier melt and retreat stimulate microbial life in turn influencing albedo and surface temperatures. In this context, the functional resilience of microbial communities in the cryosphere is of major interest. Particularly important is the ability of microorganisms and microbial communities to respond to changes in their surroundings by intracellular regulation and population shifts within functional niches, respectively. Research on microbial life exposed to permanent freeze or seasonal freeze-thaw cycles has led to astonishing findings about microbial versatility, adaptation, and diversity. Microorganisms thrive in cold habitats and new sequencing techniques have produced large amounts of genomic, metagenomic, and metatranscriptomic data that allow insights into the fascinating microbial ecology and physiology at low and subzero temperatures. Moreover, some of the frozen ecosystems such as permafrost constitute major global carbon and nitrogen storages, but can also act as sources of the greenhouse gases methane and nitrous oxide. In this book we summarize state of the art knowledge on whether environmental changes are met by a flexible microbial community retaining its function, or if the altered conditions also render the community in a state of altered properties that affect the Earth’s element cycles and climate. This book brings together research on the cryosphere’s microbiota including permafrost, glaciers, and sea ice in Arctic and Antarctic regions. Different spatial scales and levels of complexity are considered, spanning from ecosystem level to pure culture studies of model microbes in the laboratory. It aims to attract a wide range of parties with interest in the effect of climate change and/or low temperatures on microbial nutrient cycling and physiology.