Kupriashina M A, Vetchinkina E P, Burov A M, Ponomareva E G, Nikitina V E
Mikrobiologiia. 2014 Jan-Feb;83(1):41-8.
Plant-associated nitrogen-fixing soil bacteria Azospirillum brasilense were shown to reduce the gold of chloroauric acid to elemental gold, resulting in formation of gold nanoparicles. Extracellular phenoloxidizing enzymes (laccases and Mn peroxidases) were shown to participate in reduction of Au+3 (HAuCl4) to Au(0). Transmission electron microscopy revealed accumulation of colloidal gold nanoparticles of diverse shape in the culture liquid of A. brasilense strains Sp245 and Sp7. The size of the electron-dense nanospheres was 5 to 50 nm, and the size of nanoprisms varied from 5 to 300 nm. The tentative mechanism responsible for formation of gold nanoparticles is discussed.
研究表明，与植物相关的固氮土壤细菌巴西固氮螺菌能将氯金酸中的金还原为元素金，从而形成金纳米颗粒。研究还表明，细胞外酚氧化酶（漆酶和锰过氧化物酶）参与了Au+3（HAuCl4）还原为Au(0)的过程。透射电子显微镜显示，在巴西固氮螺菌菌株Sp245和Sp7的培养液中积累了形状各异的胶体金纳米颗粒。电子致密纳米球的尺寸为5至50纳米，纳米棱柱的尺寸从5至300纳米不等。文中讨论了金纳米颗粒形成的可能机制。
