Is there a common water-activity limit for the three domains of life?
Is there a common water-activity limit for the three domains of life?
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DOI：
10.1038/ismej.2014.219
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发表时间：
2015-06
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影响因子：
--
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中科院分区：
文献类型：
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古细菌和细菌构成了地球上大部分生命系统，但长期以来被认为在溶质耐受性方面不如真核生物。尽管最嗜盐的原核生物以在饱和氯化钠（水分活度 (aw) 0.755）下繁殖的能力而闻名，但一些旱生真菌通常可以在高糖浓度下（水分活度低至 0.650-0.605 aw）发芽。在这里，我们提出的证据表明，嗜盐原核生物可以生长到水活性<0.755，其中Halanaerobium lacusrosei (0.748)、盐杆菌菌株004.1 (0.728)、盐杆菌属sp。 NRC-1 和 Halococcus morrhuae (0.717)、Haloquadratum walsbyi (0.709)、Halococcus salifodinae (0.693)、Halobacter noricense (0.687)、Natrinema pallidum (0.681) 和 haloarchaeal 菌株 GN-2 和 GN-5 (0.635 aw)。此外，生长曲线的外推（倾向于给出保守估计）表明极端、专性嗜盐古菌和细菌的理论最小值降至 0.611 aw。这些值与高糖（或其他非盐水）培养基中最耐溶质的细菌（分枝杆菌属、嗜盐四联球菌、弗洛里科拉糖杆菌、金黄色葡萄球菌等）和盐水中的真核微生物（瓦莱菌属、嗜盐担孢子菌、杜氏藻属等）中的最低值进行了比较，高糖底物（例如，双孢干酵母、鲁氏接合酵母、曲霉和散囊菌）。我们还操纵了极端干旱真菌青霉曲霉和双孢酵母的离液和亲液应激源的平衡，通过这种方法，它们为菌丝体生长确定的水分活度限制（〜0.65）被降低到0.640。此外，外推法表明青霉和双孢蘑菇的理论极限分别为 0.632 和 0.636 aw。总的来说，这些发现表明存在一个共同的水分活度限制，该限制是由生命的三个领域的物理化学限制决定的。
Archaea and Bacteria constitute a majority of life systems on Earth but have long been considered inferior to Eukarya in terms of solute tolerance. Whereas the most halophilic prokaryotes are known for an ability to multiply at saturated NaCl (water activity (aw) 0.755) some xerophilic fungi can germinate, usually at high-sugar concentrations, at values as low as 0.650–0.605 aw. Here, we present evidence that halophilic prokayotes can grow down to water activities of <0.755 for Halanaerobium lacusrosei (0.748), Halobacterium strain 004.1 (0.728), Halobacterium sp. NRC-1 and Halococcus morrhuae (0.717), Haloquadratum walsbyi (0.709), Halococcus salifodinae (0.693), Halobacterium noricense (0.687), Natrinema pallidum (0.681) and haloarchaeal strains GN-2 and GN-5 (0.635 aw). Furthermore, extrapolation of growth curves (prone to giving conservative estimates) indicated theoretical minima down to 0.611 aw for extreme, obligately halophilic Archaea and Bacteria. These were compared with minima for the most solute-tolerant Bacteria in high-sugar (or other non-saline) media (Mycobacterium spp., Tetragenococcus halophilus, Saccharibacter floricola, Staphylococcus aureus and so on) and eukaryotic microbes in saline (Wallemia spp., Basipetospora halophila, Dunaliella spp. and so on) and high-sugar substrates (for example, Xeromyces bisporus, Zygosaccharomyces rouxii, Aspergillus and Eurotium spp.). We also manipulated the balance of chaotropic and kosmotropic stressors for the extreme, xerophilic fungi Aspergillus penicilloides and X. bisporus and, via this approach, their established water-activity limits for mycelial growth (∼0.65) were reduced to 0.640. Furthermore, extrapolations indicated theoretical limits of 0.632 and 0.636 aw for A. penicilloides and X. bisporus, respectively. Collectively, these findings suggest that there is a common water-activity limit that is determined by physicochemical constraints for the three domains of life.
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影响因子：
11
作者：
Auguet, Jean-Christophe;Barberan, Albert;Casamayor, Emilio O.
通讯作者：
Casamayor, Emilio O.
影响因子：
4.2
作者：
Butinar, L;Zalar, P;Gunde-Cimerman, N
通讯作者：
Gunde-Cimerman, N
影响因子：
2.9
作者：
Cifuentes, AS;González, MA;Aguilera, A
通讯作者：
Aguilera, A
影响因子：
4.2
作者：
Cray, Jonathan A.;Houghton, Jonathan D. R.;Hallsworth, John E.
通讯作者：
Hallsworth, John E.
DOI：
10.1073/pnas.1000557107
发表时间：
2010-04-27
影响因子：
11.1
作者：
Chin, Jason P.;Megaw, Julianne;Hallsworth, John E.
通讯作者：
Hallsworth, John E.