自從20世紀60年代開始，科學家就推測土壤中的細菌可以利用有傳導性的物質(zhì)來進行信息溝通,，直到現(xiàn)在,，這種說法依然是一種假設(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菌,，研究小組將其與導電磁鐵礦混合,，這將刺激細菌產(chǎn)生反應(yīng)，兩種細菌會將電子從一個傳遞至下一個,，然后一起進行攝食,，而且磁鐵礦也只是細菌完成電子轉(zhuǎn)移的一個介質(zhì)。為了確定研究者的觀察是否正確,，研究小組不良導體生銹的紅鐵,，研究發(fā)現(xiàn)細菌減慢了攝食的速度。當一個非導體混合入細菌中時,，細菌就會停止共同的攝食,。
因此研究人員基于結(jié)果推測，許多微生物可以在土壤中通過電子傳遞來進行相互交流,，盡管電子傳遞是一個很小的行為,，可是在細菌交流中卻是非常重要的。那么細菌是如何依賴傳導性物質(zhì)來在土壤中進行定位以及電子傳遞的呢,？目前并沒有人知道這種機制是如何產(chǎn)生的,，但是有些科學家表示，有可能是細菌可以促使電子鏈的產(chǎn)生以便不同細菌之間進行交流,，盡管沒有確切證據(jù),，但是研究者們正在竭盡全力去研究其機制的產(chǎn)生,。
相關(guān)研究成果刊登在了國際著名雜志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.
