自從20世紀(jì)60年代開(kāi)始，科學(xué)家就推測(cè)土壤中的細(xì)菌可以利用有傳導(dǎo)性的物質(zhì)來(lái)進(jìn)行信息溝通,，直到現(xiàn)在,，這種說(shuō)法依然是一種假設(shè)。就在兩年前,，丹麥的研究者發(fā)現(xiàn)了生存在海洋底部沉積物中的微生物可以和生存在海洋表面的微生物進(jìn)行電子交流,，這種做法可以使得其在海底獲得足夠的氧氣以維持生存。
在最新的研究中,，研究者發(fā)現(xiàn)了兩種細(xì)菌：還原硫地桿菌和脫氮硫桿菌,，這兩種微生物可以利用乙酸鹽和硝酸鹽作為生物。為了深入研究者兩種細(xì)菌,，研究小組將其與導(dǎo)電磁鐵礦混合,，這將刺激細(xì)菌產(chǎn)生反應(yīng)，兩種細(xì)菌會(huì)將電子從一個(gè)傳遞至下一個(gè),，然后一起進(jìn)行攝食,，而且磁鐵礦也只是細(xì)菌完成電子轉(zhuǎn)移的一個(gè)介質(zhì)。為了確定研究者的觀察是否正確,，研究小組不良導(dǎo)體生銹的紅鐵,，研究發(fā)現(xiàn)細(xì)菌減慢了攝食的速度。當(dāng)一個(gè)非導(dǎo)體混合入細(xì)菌中時(shí),，細(xì)菌就會(huì)停止共同的攝食,。
因此研究人員基于結(jié)果推測(cè)，許多微生物可以在土壤中通過(guò)電子傳遞來(lái)進(jìn)行相互交流,，盡管電子傳遞是一個(gè)很小的行為,，可是在細(xì)菌交流中卻是非常重要的,。那么細(xì)菌是如何依賴傳導(dǎo)性物質(zhì)來(lái)在土壤中進(jìn)行定位以及電子傳遞的呢？目前并沒(méi)有人知道這種機(jī)制是如何產(chǎn)生的,，但是有些科學(xué)家表示,，有可能是細(xì)菌可以促使電子鏈的產(chǎn)生以便不同細(xì)菌之間進(jìn)行交流，盡管沒(méi)有確切證據(jù),，但是研究者們正在竭盡全力去研究其機(jī)制的產(chǎn)生,。
相關(guān)研究成果刊登在了國(guó)際著名雜志PNAS上。（生物谷Bioon.com）
編譯自：Researchers show bacteria use natural materials to transfer electrons
編譯者：天使托
doi:10.1073/pnas.1117592109
PMC:
PMID:
Microbial interspecies electron transfer via electric currents through conductive minerals
Souichiro Katoa,1, Kazuhito Hashimotoa,b,c,2, and Kazuya Watanabea,b,d,2
In anaerobic biota, reducing equivalents (electrons) are transferred between different species of microbes [interspecies electron transfer (IET)], establishing the basis of cooperative behaviors and community functions. IET mechanisms described so far are based on diffusion of redox chemical species and/or direct contact in cell aggregates. Here, we show another possibility that IET also occurs via electric currents through natural conductive minerals. Our investigation revealed that electrically conductive magnetite nanoparticles facilitated IET from Geobacter sulfurreducens to Thiobacillus denitrificans, accomplishing acetate oxidation coupled to nitrate reduction. This two-species cooperative catabolism also occurred, albeit one order of magnitude slower, in the presence of Fe ions that worked as diffusive redox species. Semiconductive and insulating iron-oxide nanoparticles did not accelerate the cooperative catabolism. Our results suggest that microbes use conductive mineral particles as conduits of electrons, resulting in efficient IET and cooperative catabolism. Furthermore, such natural mineral conduits are considered to provide ecological advantages for users, because their investments in IET can be reduced. Given that conductive minerals are ubiquitously and abundantly present in nature, electric interactions between microbes and conductive minerals may contribute greatly to the coupling of biogeochemical reactions.
