دانلود کتاب اکستروموفیل ها از زیست شناسی تا بیوتکنولوژی

The Romans used the term extremus to describe something outside the norm, to which MacElroy (1974) conjoined philos and offered the term extremophile to define organisms—from bacteria to fishes—that inhabit extreme environments, ranging from the frozen Antarctic to abyssal hot hydrothermal vents. Extremophiles are nature’s ultimate extreme survivors that live in challenging habitats under multiple stresses of temperature, light, salinity, and pH. The quote “That which does not kill us makes us stronger” by the German philosopher Friedrich Nietzsche (1844–1900) is applicable to extremophiles. Studies on aquatic extremophiles have increased exponentially from 21 in 1997 to the current 494; likewise, the numbers of identified extremophiles from all habitats increased from 279 to 2860 in the same period. Descriptions of extremophiles, including “microbes that thrive under conditions that would kill other creatures” (Madigan and Marr 1997), “the unseen majority” (Whitman et al. 1998), “the indestructible” (Copley 1999), “ultimate extreme survivors” (Rothschild and Mancinelli 2001), “unique microbes that are found in unique environments” (Brock 2012), and “tough microbes produce tough molecules” (Anitori 2012), influenced us most to compile this collection. An earlier study on the halophiles Chlamydomonas plethora and Nitzschia frustule, isolated from Kuwait Bay, Arabian Gulf (Subba Rao et al. 2005), and more recent studies on a thermophile microalga, Scenedesmus species, from Soda Dam, New Mexico (Durvasula et al. 2015) have been the motivation behind this book. We are inspired by two more recent publications in Nature (Hashimoto et al. 2016; Bittel 2016) on proteins from an extremotolerant Tardigrade that help human DNA withstand radiation, leading us to think, “Somewhere, something incredible is waiting to be known” (credited to Carl Sagan). Of interest is the discovery of rich soil microbial communities dominated by Actinobacteria, Chloroflexi, Proteobacteria, Acidobacteria, and two new phyla AD3 and WPS-2 by Dr. Belinda C. Ferrari’s team in the frozen expanses of Antarctica. These communities aerobically scavenged atmospheric H2 and CO at rates sufficient to provide sources of energy and carbon to support their ecosystem functioning (Ji et al. 2017). This stunning finding “opens up the possibility of atmospheric gases supporting life on other planets.” This book presents an overview of the recent developments and components of the current understanding of extremophiles. Deliberately, we have steered away from descriptive taxonomic studies of these biota. Understanding extremophiles and their utility in biotechnology involves studying their habitat and their physiological and biochemical adaptations. Mechanisms for the production of biocatalysts that are functional under extreme conditions remain largely unknown. There is an unimagined profusion of microbial life with an extraordinary amount of genetic diversity, particularly the Archaea.