The Core Enigmas With AZ191 Exposed

P. Williams, R. Santos, R. Sahay, N. Neuenkirchen, C. D. McClure, I. R. Grant, J. D. R. Houghton, J. P. Quinn, D. J., Timson, S. V. Patil, R. S. Singhal, J. B. Ant��n, J. Dijksterhuis, AZ191 A. D. Hocking, B. Lievens, D. E. N. Rangel, M. A. Voytek, N. Gunde-Cimerman, A. Oren, K. N. Timmis, T. J. McGenity, and J. E. Hallsworth, submitted). For microbes on Earth, therefore, biotic activity spans approximately 40% of the available water-activity range, thus emphasizing the potency of water as a determinant of the functional biosphere. The overwhelming majority of microbial systems are metabolically active somewhere within the ranges 5��C to 40��C, and 1 to 0.900?aw, which represent even smaller portions of the environmentally pertinent temperature and water-activity ranges, i.e. only 10% in each case (Fig.?1). Of the microbial systems characterized thus www.selleckchem.com/products/INCB18424.html far, the 20 to 30 known to be active at ��?0.690?aw represent the most extreme forms of life to have penetrated low water-activity, hostile environments (Fig. 1).5 Some reports have alluded to the possibility of microbial growth and metabolism at the otherwise unprecedented water-activity values of 0.382 (for deep-sea halophiles in MgCl2-saturated brine; van der Wielen et?al., 2005), PF-2341066 2009), 0.600 [for germination of Wallemia sebi (a xerophilic basidiomycete) on high-sugar substrates; Frank and Hess, 1941] and 0.600 [reported value for optimum growth of halophiles (Jaenicke and Bohm, 1998), and biotic activity in salt lakes (Cobucci-Ponzano et?al., 2006)]. Some of these values were hypothetical (see below), and the other claims have not been accepted or have been refuted by authors of a number of subsequent studies (Pitt and Christian, 1968; Wynn-Williams, 1996; Beaty et?al., 2006; Hallsworth et?al., 2007; Kminek et?al., 2010; Oren, 2011; Stevenson and Hallsworth, 2014; A. Stevenson, J. A. Cray, J. P. Williams, R. Santos, R. Sahay, N. Neuenkirchen, C. D. McClure, I. R. Grant, J. D. R. Houghton, J. P. Quinn, D. J., Timson, S. V. Patil, R. S. Singhal, J. B. Ant��n, J. Dijksterhuis, A. D. Hocking, B. Lievens, D. E. N. Rangel, M. A. Voytek, N. Gunde-Cimerman, A. Oren, K. N. Timmis, T. J. McGenity, and J. E. Hallsworth, submitted).6 The Don Juan Pond (located within the McMurdo Dry Valleys, Antarctica) is a CaCl2-saturated brine pool situated in a closed basin and fed by seasonal meltwater streams and deliquescent seepages, both of which are thought to deliver CaCl2 to the lake (Dickson et?al., 2013). Its volume fluctuates but is typically ??3000?m3 (slightly larger than an Olympic swimming pool), and it is among the most saline large-scale bodies of water known on Earth.