Abstract
Biosynthesizing Au nanoparticles(AuNPs)from gold-bearing scraps provides a sustainable method to meet the urgent demand for AuNPs.However,it remains challenging to efficiently biosynthesize AuNPs of which the diameter is less than 10 nm from a trace amount of Au3+concentration at the level of tens ppm.Here,we constructed an exoelectrogenic cell(eCell)-conductive reduced-graphene-oxide aero-gel(rGA)biohybrid by assembling Shewanella sp.S1(SS1)as living biocatalyst and rGA as conductive ad-sorbent,in which Au3+at trace concentrations would be enriched by the adsorption of rGA and reduced to AuNPs through the extracellular electron transfer(EET)of SS1.To regulate the size of the synthe-sized AuNPs to 10 nm,the strain SS1 was engineered to enhance its EET,resulting in strain RS2(pYYD-Ptac-ribADEHC & pHG13-Pbad-omcC in SS1).Strain RS2 was further assembled with rGA to construct the RS2-rGA biohybrid,which could synthesize AuNPs with the size of 7.62±2.82 nm from 60 ppm Au3+so-lution.The eCell-rGA biohybrid integrated Au3+adsorption and reduction,which enabled AuNPs biosyn-thesis from a trace amount of Au3+.Thus,the required Au3+ions concentration was reduced by one or two orders of magnitude compared with conventional methods of AuNPs biosynthesis.Our work devel-oped an AuNPs size regulation technology via engineering eCell's EET with synthetic biology methods,providing a feasible approach to synthesize AuNPs with controllable size from trace level of gold ions.
基金项目
国家重点研发计划(2018YFA0901300)
国家自然科学基金(NSFC 32071411)
国家自然科学基金(NSFC 32001034)
国家自然科学基金(NSFC 31701569)
Young Science and Technology Talents Growth Project of Education Department of Guizhou Province(KY[2018]445)
Key Laboratory of Wuliangyeflavor Liquor Solidstate Fermentation,China National Light Industry(2021JJ013)
NETL
NSTL
万方数据