Sheds new light on the microbial ecology and physiology of the Earth’s polar regions. • Examines the microbial investigations during the International Polar Year of 2008 focusing on the Arctic and Antarctic, along with earlier investigations on critical environmental issues such as climate change, ozone depletion, and elemental cycling. • Offers a survey of what is known and unknown about the microbial inhabitants of polar environments, addresses the adaptations and physiology of cold-adapted microorganisms, and explores the ecological role that polar microbial communities play in biogeochemical cycling. • Presents the challenges that polar and subpolar microorganisms face and describes the lowest temperatures in which microbial life can exist—and the prospects for life on other planets. Recommended for a general microbiology audience as well as for scientists and students in all areas of biology and geomicrobiology.

Pollution has accompanied polar exploration since Captain John Davis' arrival on the Antarctic continent in 1821 and has become an unavoidable consequence of oil spills in our polar regions. Fortunately, many of the organisms indigenous to Polar ecosystems have the ability to degrade pollutants. It is this metabolic capacity that forms the basis fo

This book is a printed edition of the Special Issue "Polar Microbiology: Recent Advances and Future Perspectives" that was published in Biology

Marine and freshwater polar environments are characterized by intense physical forces and strong seasonal variations. The persistent cold and sometimes inhospitable conditions create unique ecosystems and habitats for microbial life. Polar microbial communities are diverse productive assemblages, which drive biogeochemical cycles and support higher food-webs across the Arctic and over much of the Antarctic. Recent studies on the biogeography of microbial species have revealed phylogenetically diverse polar ecotypes, suggesting adaptation to seasonal darkness, sea-ice coverage and high summer irradiance. Because of the diversity of habitats related to atmospheric and oceanic circulation, and the formation and melting of ice, high latitude oceans and lakes are ideal environments to investigate composition and functionality of microbial communities. In addition, polar regions are responding more dramatically to climate change compared to temperate environments and there is an urgent need to identify sensitive indicators of ecosystem history, that may be sentinels for change or adaptation. For instance, Antarctic lakes provide useful model systems to study microbial evolution and climate history. Hence, it becomes essential and timely to better understand factors controlling the microbes, and how, in turn, they may affect the functioning of these fragile ecosystems. Polar microbiology is an expanding field of research with exciting possibilities to provide new insights into microbial ecology and evolution. With this Research Topic we seek to bring together polar microbiologists studying different aquatic systems and components of the microbial food web, to stimulate discussion and reflect on these sensitive environments in a changing world perspective.

Scientific research on cold-adapted microorganisms (specifically polar microbes) is of great interest, since Arctic and Antarctic regions harbor diverse and active populations of microorganisms. However, these microorganisms are subject to impacts of environmental perturbations. For example, climate change will modulate the distribution and activity of many cyanobacteria and algal species in polar environments that contribute significantly to global carbon fixation and oxygen production. Moreover, many microorganisms that have remained frozen for thousands of years can revive their metabolic activity and re-join the modern microbial community. For survival in freezing environments, polar microorganisms have established specific regulatory mechanisms which are now being challenged by new, rapidly changing environmental conditions. Remarkable progress has been made to uncover microbial adaptation to anthropogenic activities such as high irradiance, nutritional deprivation, UV-B radiation, heat, cold, desiccation, and heavy metals. Studies have enabled a basic understanding of gene regulatory pathways for morphological, physiological, metabolic, and genetic adaptations to various environmental stresses. To further elucidate physiological adaptation mechanisms and molecular diversity in polar regions, this Research Topic is focused on microbes in polar regions, looking at their biodiversity, ecological adaptations, the impact of climate change on their lifestyles, and biotechnological application of microbes for a sustainable future.

Philip Mladenov provides a comprehensive overview of marine biology, providing a tour of marine life and marine processes that ranges from the polar oceans to tropical coral reefs; and from the intertidal to the hydrothermal vents of the deep sea.