Scale-up of the production of highly reactive biogenic magnetite nanoparticles using Geobacter sulfurreducens.
Scale-up of the production of highly reactive biogenic magnetite nanoparticles using Geobacter sulfurreducens.
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DOI：
10.1098/rsif.2015.0240
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发表时间：
2015-06-06
期刊：
影响因子：
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通讯作者：
Lloyd JR
中科院分区：
文献类型：
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作者：
Byrne JM;Muhamadali H;Coker VS;Cooper J;Lloyd JR
尽管有许多大规模商业微生物合成有机生物制品的例子，但很少有研究解决微生物系统大规模生产无机功能性生物材料的明显潜力。在这里，我们通过关注铁（III）还原细菌硫还原地杆菌生产纳米级生物磁铁矿颗粒来解决这个问题，该细菌已成功地从实验室规模扩大到中试工厂规模的生产，同时保持了使该材料非常适合商业开发的表面反应性和磁性。在最大规模的测试中，细菌在50 l的生物反应器中生长，收获，然后接种到含有铁(III)-氢氧化物和电子供体和介质的缓冲溶液中，这促进了磁铁矿在24小时内的形成。这一过程能够产生高达120 g的生物磁铁矿。第二步从10 ml扩大到10 l，粒径分布保持在10 ~ 15 nm之间，磁性能和表面反应性保持不变；后者表现为Cr（VI）的还原。该工艺为磁铁矿生产提供了一种环境友好的途径，并可作为苛刻的合成技术的替代方案，具有用于生产公斤至吨数量的明显潜力。
Although there are numerous examples of large-scale commercial microbial synthesis routes for organic bioproducts, few studies have addressed the obvious potential for microbial systems to produce inorganic functional biomaterials at scale. Here we address this by focusing on the production of nanoscale biomagnetite particles by the Fe(III)-reducing bacterium Geobacter sulfurreducens, which was scaled up successfully from laboratory- to pilot plant-scale production, while maintaining the surface reactivity and magnetic properties which make this material well suited to commercial exploitation. At the largest scale tested, the bacterium was grown in a 50 l bioreactor, harvested and then inoculated into a buffer solution containing Fe(III)-oxyhydroxide and an electron donor and mediator, which promoted the formation of magnetite in under 24 h. This procedure was capable of producing up to 120 g of biomagnetite. The particle size distribution was maintained between 10 and 15 nm during scale-up of this second step from 10 ml to 10 l, with conserved magnetic properties and surface reactivity; the latter demonstrated by the reduction of Cr(VI). The process presented provides an environmentally benign route to magnetite production and serves as an alternative to harsher synthetic techniques, with the clear potential to be used to produce kilogram to tonne quantities.