Biorecovery is emerging as a promising approach to retrieve gold from various sources, while its efficiency is usually restricted by the limited functional groups on natural microbial biomass surface. This study aims to intensify Pycnoporus sanguineus boosted sorption-reduction coupled gold biorecovery process via microbial surface modification. Results showed that grafting polyallylamine hydrochloride onto P. sanguineus biomass surface increased amino group content on microbial biomass surface from 1.29 to 2.81 mmol/g. When applying modified biomass to gold biorecovery with initial gold concentrations of 1.0, 2.0 and 3.0 mM, biosorption equilibrium time shortened to the 12.5%, 37.5% and 41.7% of those obtained with pristine biomass, and sorption rate constants correspondingly increased to 11.2, 3.1 and 3.7 folds as well. Maximum sorption capacity increased 30% and the affinity between biomass and gold enhanced heavily after microbial surface modification. Meanwhile, microbial surface modification favored gold reduction and gold nanoparticles (AuNPs) formation. The change of microbial biomass morphology from smooth surface with some branched structure to layered stacking structure with many pores and the increase of amino group content on microbial biomass surface were the main impetus for the gold bioreocovery process intensification.

中文翻译：

---

通过微生物表面改性强化吸附还原耦合的金生物回收过程：对金吸附和还原的影响

生物回收正在成为一种从各种来源回收黄金的有前途的方法，但其效率通常受到天然微生物生物质表面有限官能团的限制。本研究旨在通过微生物表面改性强化 Pycnoporus sanguineus 促进吸附-还原耦合的金生物回收过程。结果表明，将聚烯丙胺盐酸盐接枝到血红松生物质表面使微生物生物质表面的氨基含量从1.29 mmol/g 增加到2.81 mmol/g。当将改性生物质应用于初始金浓度为 1.0、2.0 和 3.0 mM 的金生物回收时，生物吸附平衡时间缩短至原始生物量的 12.5%、37.5% 和 41.7%，吸附速率常数相应增加至 11.2、3.1。以及 3.7 折。微生物表面改性后，最大吸附能力提高了 30%，生物质与金之间的亲和力大大增强。同时，微生物表面改性有利于金还原和金纳米粒子 (AuNPs) 的形成。微生物生物质形态从具有一些分支结构的光滑表面到具有许多孔隙的层状堆积结构的变化以及微生物生物质表面氨基含量的增加是金生物回收过程强化的主要推动力。