Antarctic heterotrophic bacterium Hymenobacter nivis P3T displays light-enhanced growth and expresses putative photoactive proteins
Antarctic heterotrophic bacterium Hymenobacter nivis P3T displays light-enhanced growth and expresses putative photoactive proteins
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南极异养细菌雪膜杆菌 P3T 表现出光增强生长并表达假定的光活性蛋白
DOI：
10.1111/1758-2229.12702
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发表时间：
2018
影响因子：
3.3
通讯作者：
Fukui Manabu
中科院分区：
文献类型：
--
作者：
Terashima Mia;Ohashi Keisuke;Takasuka Taichi E.;Kojima Hisaya;Fukui Manabu
HymenarynivisP3T是从南极红雪中分离出的一种异养细菌，由藻华产生。尽管没有光合作用，H. nivis主要在暴露于强光和紫外线照射的红雪环境中发现，这表明该物种可以在如此恶劣的条件下蓬勃发展。为了进一步了解南极雪表环境下的适应策略，本文对南极雪表环境下的黑腹果蝇基因组进行了研究。nivisP3T的测序和分析，鉴定了编码光反应蛋白如蛋白紫质、光敏色素、光裂合酶和几个隐花色素拷贝的puridine基因。基于培养的实验表明，H. nivisP3T在光照条件下生长显著增强，而黑暗条件下胞外聚合物增加。此外，通过蛋白质组学分析确定了几种推定的光反应蛋白的表达。这些结果表明，H. nivisP3T能够潜在地利用光，这可以解释其在南极洲红雪表面环境中的优势。独创性显著性声明蛋白视紫红质在异养细菌中的作用尚未得到很好的表征，因为迄今为止只有少数携带蛋白视紫红质的分离株通过基于培养的实验显示出具有光增强的表型。这是第一项证明非海洋嗜冷菌和属Hymenophile成员的光刺激生长和光活性蛋白质表达证据的研究。这也是第一个为该属提供全面蛋白质组信息的研究。这项研究提供了重要的结果，以了解在南极洲雪面环境中茁壮成长的异养非光合细菌的适应机制，并证明光利用在促进生长中的作用，可能通过蛋白视紫质。
Hymenobacter nivisP3Tis a heterotrophic bacterium isolated from Antarctic red snow generated by algal blooms. Despite being non‐photosynthetic,H. niviswas dominantly found in the red snow environment that is exposed to high light and UV irradiation, suggesting that this species can flourish under such harsh conditions. In order to further understand the adaptive strategies on the snow surface environment of Antarctica, the genome ofH. nivisP3Twas sequenced and analyzed, which identified genes putatively encoding for light‐reactive proteins such as proteorhodopsin, phytochrome, photolyase and several copies of cryptochromes. Culture‐based experiments revealed thatH. nivisP3Tgrowth was significantly enhanced under light conditions, while dark conditions had increased extracellular polymeric substances. Furthermore, the expression of several putative light‐reactive proteins was determined by proteomic analysis. These results indicate thatH. nivisP3Tis able to potentially utilize light, which may explain its dominance on the red snow surface environment of Antarctica.Originality‐significance statementThe role of proteorhodopsin in heterotrophic bacteria is not well‐characterized, as only a handful of proteorhodopsin‐harbouring isolates were shown to have a light‐enhanced phenotype through culture‐based experiments to date. This is the first study that demonstrates light‐stimulated growth and protein expression evidence of photoactive proteins for a non‐marine psychrophile and for a member of the genusHymenobacter. It is also the first study that provides comprehensive proteome information for this genus. This study presents significant results in understanding the adaptive mechanism of a heterotrophic non‐photosynthetic bacterium thriving on the snow surface environment of Antarctica as well as demonstrating the role of light‐utilization in promoting growth, possibly through proteorhodopsin.