Institute of Agricultural Resources and Environment, Guangdong Academy of Agricultural Sciences, Key Laboratory of Plant Nutrition and Fertilizer in South Region, Ministry of Agriculture, Guangdong Key Laboratory of Nutrient Cycling and Farmland Conservation, Guangzhou, 510640, China.
School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China.
World J Microbiol Biotechnol. 2020 Feb 24;36(3):38. doi: 10.1007/s11274-020-2796-5.
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.
生物回收作为一种从各种来源中回收金的有前途的方法正在出现，但其效率通常受到天然微生物生物质表面有限的功能基团的限制。本研究旨在通过微生物表面修饰来强化血红色香菇促进的吸附-还原偶联金生物回收过程。结果表明，将盐酸聚烯丙胺接枝到血红色香菇生物质表面，使微生物生物质表面的氨基含量从 1.29mmol/g 增加到 2.81mmol/g。当将改性生物质应用于初始金浓度为 1.0、2.0 和 3.0mM 的金生物回收时，生物吸附平衡时间缩短到原始生物质的 12.5%、37.5%和 41.7%，吸附速率常数相应增加了 11.2、3.1 和 3.7 倍。最大吸附容量增加了 30%，微生物表面修饰后生物量与金之间的亲和力大大增强。同时，微生物表面修饰有利于金的还原和金纳米粒子（AuNPs）的形成。微生物生物质形貌从具有一些分支结构的光滑表面变为具有许多孔的层状堆叠结构，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动力。
