Sakamoto Toshio, Wei Yang, Yuasa Koki, Nishiyama Yoshitaka
School of Biological Science and Technology, College of Science and Engineering, Kanazawa University.
Division of Biological Sciences, Graduate School of Natural Science and Technology.
J Gen Appl Microbiol. 2022 Nov 22;68(4):169-174. doi: 10.2323/jgam.2022.01.003. Epub 2022 May 20.
The terrestrial cyanobacterium Nostoc commune is an anhydrobiotic organism with extreme longevity. Recovery of photosynthesis by rehydration was examined using our laboratory stocks of dry N. commune thalli after long-term storage in a desiccated state. In the samples stored at room temperature for over 8 years, photosynthetic oxygen evolution was barely detectable, whereas oxygen consumption was recovered. There was an exceptional case in which photosynthetic oxygen evolution recovered after 8 years of storage at room temperature. Both photosynthetic oxygen evolution and respiratory oxygen consumption were recovered in dry thalli stored at -20°C for over 15 years. Consistent with the recovery of photosynthetic oxygen evolution, Fv/Fm was detected in the samples stored at -20°C at levels similar to those of freshly collected N. commune colonies. Carotenoids, scytonemin and chlorophyll a appeared to be intact in the dry thalli stored at -20°C, but β-carotene was not detected in the samples stored at room temperature. α-Tocopherol was intact in the samples stored at -20°C but was degraded in the samples stored at room temperature. These results suggest that dry thalli of N. commune are capable of sustaining biological activities for a long time, although they are gradually damaged when stored at room temperature.
陆生蓝细菌普通念珠藻是一种具有超长寿命的脱水生物。我们使用实验室保存的干燥普通念珠藻藻体，研究了在干燥状态下长期储存后通过复水恢复光合作用的情况。在室温下储存超过8年的样本中，几乎检测不到光合放氧，而耗氧得以恢复。有一个特殊案例，室温储存8年后光合放氧得以恢复。在-20°C下储存超过15年的干燥藻体中，光合放氧和呼吸耗氧均得以恢复。与光合放氧的恢复一致，在-20°C下储存的样本中检测到的Fv/Fm水平与新鲜采集的普通念珠藻菌落相似。在-20°C下储存的干燥藻体中，类胡萝卜素、藻青素和叶绿素a似乎完好无损，但在室温下储存的样本中未检测到β-胡萝卜素。α-生育酚在-20°C下储存的样本中完好无损，但在室温下储存的样本中降解。这些结果表明，普通念珠藻的干燥藻体能够长时间维持生物活性，尽管在室温下储存时它们会逐渐受损。
