Magnetite compensates for the lack of a pilin-associated c-type cytochrome in extracellular electron exchange
Magnetite compensates for the lack of a pilin-associated c-type cytochrome in extracellular electron exchange
复制标题
磁铁矿补偿了细胞外电子交换中菌毛蛋白相关的 c 型细胞色素的缺乏
DOI：
10.1111/1462-2920.12485
复制
发表时间：
2015-03-01
影响因子：
5.1
通讯作者：
Lovley, Derek R.
中科院分区：
文献类型：
--
作者：
Liu, Fanghua;Rotaru, Amelia-Elena;Lovley, Derek R.
纳米级磁铁矿可以促进微生物胞外电子转移，在生物地球化学循环、生物修复和多种生物能源策略中发挥重要作用，但刺激胞外电子转移的机制尚不清楚。进一步的研究表明，磁铁矿附着在地杆菌的导电毛上，其方式与多血红素c型细胞色素OmcS与硫还原地杆菌毛的结合相似。磁铁矿赋予缺乏omcs的菌株胞外电子能力，使其无法参与种间电子转移或Fe（III）氧化物还原。当有磁铁矿存在时，野生型细胞抑制OmcS基因的表达，这表明当有磁铁矿存在时，细胞可能需要产生更少的OmcS。磁铁矿可以弥补多血红素c型细胞色素缺乏电子传递功能的发现不仅对现代微生物的功能有意义，而且对微生物电子传递机制的早期进化也有意义。
Nanoscale magnetite can facilitate microbial extracellular electron transfer that plays an important role in biogeochemical cycles, bioremediation and several bioenergy strategies, but the mechanisms for the stimulation of extracellular electron transfer are poorly understood. Further investigation revealed that magnetite attached to the electrically conductive pili of Geobacter species in a manner reminiscent of the association of the multi-heme c-type cytochrome OmcS with the pili of Geobacter sulfurreducens. Magnetite conferred extracellular electron capabilities on an OmcS-deficient strain unable to participate in interspecies electron transfer or Fe(III) oxide reduction. In the presence of magnetite wild-type cells repressed expression of the OmcS gene, suggesting that cells might need to produce less OmcS when magnetite was available. The finding that magnetite can compensate for the lack of the electron transfer functions of a multi-heme c-type cytochrome has implications not only for the function of modern microbes, but also for the early evolution of microbial electron transport mechanisms.