有些细菌能休眠上千年，遇水又“复活”，它们是怎么熬过这么久的？
Some bacteria sleep for millennia then “revive” with water—how do they survive so long?
它们形成坚固的内生孢子：把DNA和少量必要物质紧紧包裹、脱水、代谢几乎停止，像按了暂停键。孢子抗热、抗辐射、抗干燥，环境合适时重新吸水苏醒分裂。
They form tough endospores: DNA and essentials are packed tight, dehydrated, metabolism nearly halted—like pressing pause. Spores resist heat, radiation and dryness, reviving and dividing when conditions return.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#内生孢子 #休眠 #复苏
嗜酸原核生物在细胞质pH接近中性的情况下,依靠哪些机制维持跨膜pH稳态并避免酸性外环境对胞内酶系的破坏?
How do acidophilic prokaryotes maintain transmembrane pH homeostasis—keeping cytoplasmic pH near neutral—despite growth in strongly acidic environments that would denature most cytosolic enzymes?
耐酸菌主要通过三种协同机制应对极端酸性:反向转运蛋白以K+/H+和Na+/H+逆向运输将流入的质子排出胞外;细胞膜富含饱和脂肪酸并带有疏水基团修饰,显著降低质子通透性;外膜蛋白和表面糖链形成缓冲层中和局部酸度。此外,胞内伴侣蛋白可修复少量已发生部分变性的蛋白质。这些机制使 Acidihalobacter prosperus 等菌株能在pH 1–2的酸性矿坑水中完成铁硫氧化代谢。
Acidophiles counter extreme acidity through three cooperating mechanisms: K+/H+ and Na+/H+ antiporters expel the protons that leak inward; membranes enriched in saturated fatty acids with hydrophobic modifications sharply reduce proton permeability; and outer-membrane proteins plus surface polysaccharides form a buffering layer that neutralizes local acidity. Cytoplasmic chaperones additionally refold the small fraction of proteins that partially unfold. Together these systems let organisms such as Acidihalobacter prosperus run iron- and sulfur-oxidizing metabolism in pH 1–2 mine water.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 来源待核验 · Source pending review
来源 · Source
出处备注：此条未指向带版次的可引用著作（通识性内容、机构文件或未展开的英文书名），本库不提供独立书目出处；如需精确引用，需由编辑补全具体篇目与版次。
Baker-Austin C & Dopson M, Life in acid: pH homeostasis in acidophiles, Trends in Microbiology 18(2):55-63 (2010)
Baker-Austin C & Dopson M, Life in acid: pH homeostasis in acidophiles, Trends in Microbiology 18(2):55-63 (2010)
#极端微生物 #pH稳态
嗜盐菌为什么需要高盐环境？
Why do halophiles require high-salt environments?
它们靠在细胞内累积高浓度的钾离子或兼容溶质来平衡外界渗透压，并拥有适应高盐的酶和膜。
They balance external osmotic pressure with intracellular K+ or compatible solutes and possess salt-adapted enzymes and membranes.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#嗜盐菌 #渗透压
水熊虫为什么能扛住极端干燥和强辐射？
Why can tardigrades survive extreme dehydration and radiation?
脱水时它们进入隐生状态、合成无水保护蛋白并折叠 DNA，复苏后再修复损伤，可承受接近真空与强辐射。
In cryptobiosis they make protective proteins and compact DNA, then repair damage after rehydration, enduring near-vacuum and radiation.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#水熊虫 #隐生
耐辐射奇球菌能承受把自身基因组打成碎片的数千戈瑞伽马射线——它的看家本领却不是保护DNA免于断裂,而是另辟蹊径,妙在何处?
Deinococcus radiodurans endures gamma doses of several kilograys that shatter its own genome—yet its signature skill is not keeping DNA intact. Where does its ingenuity actually lie?
锰基抗氧化络合物优先保护蛋白质不受辐射氧化,于是DNA虽已碎裂数百段,修复酶体系本身仍运转如常。该菌借ESDSA同源重组途径,以完整拷贝为模板延长单链尾端,几十小时内把散乱片段逐段拼回环状染色体。“先保蛋白、后修DNA”的取舍策略,同样解释了它对干旱环境的出色耐受。
Manganese-based antioxidant complexes shield proteins from radiation-driven oxidation, so although the DNA breaks into hundreds of fragments, the repair machinery itself keeps working. Through ESDSA homologous recombination the bacterium extends long single-stranded tails templated on intact copies and stitches the scattered pieces back into a circular chromosome over tens of hours. Protecting proteins first and repairing DNA second equally explains its remarkable tolerance of desiccation.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-11-02
来源 · Source
Cox 与 Battista 解析耐辐射奇球菌生存机制的综述,《Nature Reviews Microbiology》2005年第3卷第882页。
Cox MM & Battista JR, Deinococcus radiodurans—the consummate survivor, Nature Reviews Microbiology 3: 882 (2005).
独立核验依据 · Independent verification: 核验依据 1 CROSSREF 标识 10.1038/nrmicro1264：Deinococcus radiodurans
#极端环境生物 #辐射损伤修复
什么是嗜极生物？
What are extremophiles?
它们是一类在极端温度、盐度、酸碱或辐射下也能繁盛的微生物，挑战了我们对生命宜居的传统认识。
They are microbes that thrive in extreme heat, salt, pH, or radiation, challenging traditional ideas of where life can live.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-08-23 · 2 条独立证据
来源 · Source
Urry 等,《Campbell Biology》第11版,Pearson,2017
L. A. Urry et al., Campbell Biology, 11th ed., Pearson, 2017
独立核验依据 · Independent verification: 核验依据 2 ISBN 978-0-13-409341-3 (11th ed., Pearson)
#嗜极生物 #极端环境