This book presents a summary of terrestrial microbial processes, which are a key factor in supporting healthy life on our planet. The authors explain how microorganisms maintain the soil ecosystem through recycling carbon and nitrogen and then provide insights into how soil microbiology processes integrate into ecosystem science, helping to achieve successful bioremediation as well as safe and effective operation of landfills, and enabling the design of composting processes that reduce the amount of waste that is placed in landfills. The book also explores the effect of human land use, including restoration on soil microbial communities and the response of wetland microbial communities to anthropogenic pollutants. Lastly it discusses the role of fungi in causing damaging, and often lethal, infectious diseases in plants and animals.

Obtaining and analyzing samples is challenging in subsurface science. This first-of-its-kind reference book addresses accomplishments in this field-from drilling to sample work-up. A collaborative approach is taken, involving the efforts of microbiologists, geochemists, hydrologists, and drilling and mining experts to present a comprehensive view of subsurface research. The text provides practical information about obtaining, analyzing, and evaluating subsurface materials; the current status of subsurface microbial ecology; and describes several applications that will interest a variety of readers, including engineers, physical, and life scientists.

In the past 15 years, there has been steady growth in work relating to the microbial iron cycle. It is now well established that in anaerobic environments coupling of organic matter utilization to Fe reduction is a major pathway for anaerobic respiration. In iron-rich circumneutral environments that exist at oxic-anoxic boundaries, significant progress has been made in demonstrating that unique groups of microbes can grow either aerobically or anaerobically using Fe as a primary energy source. Likewise, in high iron acidic environments, progress has been made in the study of communities of microbes that oxidize iron, and in understanding the details of how certain of these organisms gain energy from Fe-oxidation. On the iron scarcity side, it is now appreciated that in large areas of the open ocean Fe is a key limiting nutrient; thus, a great deal of research is going into understanding the strategies microbial cells, principally phytoplankton, use to acquire iron, and how the iron cycle may impact other nutrient cycles. Finally, due to its abundance, iron has played an important role in the evolution of Earth’s primary biogeochemical cycles through time. The aim of this Research Topic is to gather contributions from scientists working in diverse disciplines who have common interests in iron cycling at the process level, and at the organismal level, both from the perspective of Fe as an energy source, or as a limiting nutrient for primary productivity in the ocean. The range of disciplines may include: geomicrobiologists, microbial ecologists, microbial physiologists, biological oceanographers, and biogeochemists. Articles can be original research, techniques, reviews, or synthesis papers. An overarching goal is to demonstrate the environmental breadth of the iron cycle, and foster understanding between different scientific communities who may not always be aware of one another’s work.

Bioremediation, the use of microorganisms to degrade, sequester, or remove environmental contaminants, is an urgent need of our planet for protection and restoration from toxic contaminants. This book not only provides cutting edge information about bioremediation of aquatic and terrestrial habitats, but also highlights the gaps in our knowledge of

Water is usually referred to as the ‘Molecule of Life’. It constitutes the most abundant molecule in living (micro)organisms and is also essential for critical biochemical reactions, both for the global functioning and maintenance of Ecosystems (e.g., Photosynthesis) and individual (microbial) cells (e.g., ATP hydrolysis). However, most of Earth’s terrestrial environments present deficiencies in bioavailable water. Arid environments cover around a third of the land’s surface, are found on the six continents and, with the anthropogenic desertification phenomenon, will increase. Commonly defined by having a ratio of precipitation to potential evapotranspiration (P/PET) below 1, arid environments, being either hot or cold, are characterized by scant and erratic plant growth and low densities in macro-fauna. Consequently, these ecosystems are microbially mediated with microbial communities particularly driving the essential Na and C biogeochemical cycles. Due to the relatively simple trophic structure of these biomes, arid terrestrial environments have subsequently been used as ideal ecosystems to capture and model interactions in edaphic microbial communities. To date, we have been able to demonstrate that edaphic microorganisms (i.e., Fungi, Bacteria, Archaea, and Viruses) in arid environments are abundant, highly diverse, different from those of other terrestrial systems (both in terms of diversity and function), and are important for the stability and productivity of these ecosystems. Moreover, arid terrestrial systems are generally considered Mars-like environments. Thus, they have been the favored destination for astro(micro)biologists aiming to better understand life’s potential distribution and adaptation strategies in the Universe and develop terraforming approaches. Altogether, these points demonstrate the importance of significantly improving our knowledge in the microbial community composition (particularly for Fungi, Archaea and Viruses), assembly processes and functional potentials of arid terrestrial systems, as well as their adaptation mechanisms to aridity (and generally to various other environmental stresses). This Research Topic was proposed to provide further insights on the microbial ecology of hot and cold arid edaphic systems. We provide a detailed review and nine research articles, spanning hot and cold deserts, edaphic, rhizospheric, BSC and endolithic environments as well as culture-dependent and -independant approaches.

This book brings together many of the world’s leading experts in the fields of Antarctic terrestrial soil ecology, providing a comprehensive and completely up-to-date analysis of the status of Antarctic soil microbiology. Antarctic terrestrial soils represent one of the most extreme environments on Earth. Once thought to be largely sterile, it is now known that these diverse and often specialized extreme habitats harbor a very wide range of different microorganisms. Antarctic soil communities are relatively simple, but not unsophisticated. Recent phylogenetic and microscopic studies have demonstrated that these communities have well established trophic structuring and play a significant role in nutrient cycling in these cold and often dry desert ecosystems. They are surprisingly responsive to change and potentially sensitive to climatic perturbation. Antarctic terrestrial soils also harbor specialized ‘refuge’habitats, where microbial communities develop under (and within) translucent rocks. These cryptic habitats offer unique models for understanding the physical and biological ‘drivers’ of community development, function and evolution.

Microbial Biomass informs readers of the ongoing global revolution in understanding soil and ecosystem microbial processes. The first paper on the subject was written by David Jenkinson in 1966, and here new insights and expansions are given on the fascinating world of soil microbial processes. In terms of contemporary issues, it also serves to support urgent efforts to sustainably manage land to feed a growing world population without compromising the environment. It presents new methods of investigation which are leading to more sustainable management of ecosystems, and improved understanding of ecosystem changes in an increasingly warmer world.The book approaches the topic by looking at the emergence of our understanding of soil biological processes, and begins by tracing the conception and first measurement of soil microbial biomass. Following this, changes in ecosystems, and in natural ecosystem processes are discussed in relation to land management issues and global change. Microbial biomass and its diversity are recognized as key factors in finding solutions for more sustainable land and ecosystem management, aided by new molecular and other tools. Information from the use of these tools is now being incorporated into emerging microbial-explicit predictive models, to help us study changes in earth system processes.Perfect for use in research and practice, this book is written for undergraduate and graduate students, researchers and professionals of agronomy, chemistry, geology, physical geography, ecology, biology, microbiology, silviculture and soil science.

The deep subsurface is, in addition to space, one of the last unknown frontiers to human kind. A significant part of life on Earth resides in the deep subsurface, hiding great potential of microbial life of which we know only little. The conditions in the deep terrestrial subsurface are thought to resemble those of early Earth, which makes this environment an analog for studying early life in addition to possible extraterrestrial life in ultra-extreme conditions. Early microorganisms played a great role in shaping the conditions on the young Earth. Even today deep subsurface microorganisms interact with their geological environment transforming the conditions in the groundwater and on rock surfaces. Essential elements for life are richly present but in difficultly accessible form. The elements driving the microbial deep life is still not completely identified. Most of the microorganisms detected by novel molecular techniques still lack cultured representatives. Nevertheless, using modern sequencing techniques and bioinformatics the functional roles of these microorganisms are being revealed. We are starting to see the differences and similarities between the life in the deep subsurface and surface domains. We may even begin to see the function of evolution by comparing deep life to life closer to the surface of Earth. Deep life consists of organisms from all known domains of life. This Research Topic reveals some of the rich diversity and functional properties of the great biomass residing in the deep dark subsurface.