Department of Earth Sciences, Montana State University, Bozeman, MT 59717, USA.
Environ Microbiol. 2011 Aug;13(8):2269-78. doi: 10.1111/j.1462-2920.2011.02485.x. Epub 2011 Apr 28.
Metabolic activity, but not growth, has been observed in ice at temperatures from -5°C to -32°C. To improve understanding of metabolism in ice, we simultaneously examined various aspects of metabolism ((14) C-acetate utilization, macromolecule syntheses and viability via reduction of CTC) of the glacial isolates Sporosarcina sp. B5 and Chryseobacterium sp. V3519-10 during incubation in nutrient-rich ice and brine at -5°C for 50 days. Measured rates of acetate utilization and macromolecule syntheses were high in the first 20 days suggesting adjustment to the lower temperatures and higher salt concentrations of both the liquid vein network in the ice and the brine. Following this adjustment, reproductive growth of both organisms was evident in brine, and suggested for Sporosarcina sp. B5 in ice by increases in cell numbers and biomass. Chryseobacterium sp. V3519-10 cells incubated in ice remained active. These data indicate that neither low temperature nor high salt concentrations prohibit growth in ice, but some other aspect of living within ice slows growth to within the detection limits of current methodologies. These results imply that microbial growth is plausible in natural ice systems with comparable temperatures and sufficient nutrients, such as debris-rich basal ices of glaciers and ice masses.
在-5°C 至-32°C 的温度下，已经观察到冰中的代谢活性，但不是生长。为了更好地了解冰中的代谢，我们同时研究了冰川分离物 Sporosarcina sp. B5 和 Chryseobacterium sp. V3519-10 在-5°C 的富营养冰和盐水中共培养 50 天时的代谢（通过 CTC 还原利用 14C-乙酸盐、大分子合成和活力）的各个方面。在前 20 天，乙酸盐利用和大分子合成的测量速率很高，表明它们适应了冰中的液体脉管网和盐水的较低温度和较高盐浓度。在这种调整之后，两种生物在盐水中都表现出了生殖生长，并且 Sporosarcina sp. B5 在冰中通过细胞数量和生物量的增加表明了这一点。在冰中培养的 Chryseobacterium sp. V3519-10 细胞仍然活跃。这些数据表明，低温和高盐浓度都不会阻止冰中的生长，但冰中生存的其他某些方面将生长速度减缓到当前方法学的检测极限内。这些结果表明，在具有类似温度和足够营养的天然冰系统中，微生物生长是合理的，例如冰川和冰体的富含碎屑的基冰。
