Proteomic Insights into the Adaptation of Acidithiobacillus ferridurans to Municipal Solid Waste Incineration Residues for Enhanced Bioleaching Efficiency

Acidithiobacillus spp. have traditionally
been
utilized to extract metals from mineral ores through bioleaching.
This process has recently expanded to include artificial ores, such
as those derived from municipal solid waste incineration (MSWI) residues.
Previous studies have indicated that microbial adaptation enhances
bioleaching efficiency, prompting this study to identify proteins
involved in the adaptation of A. ferridurans to MSWI residues. We employed data-independent acquisition-parallel
accumulation serial fragmentation to determine the proteomic response
of A. ferridurans DSM 583 to three
distinct materials: bottom ash (BA), kettle ash (KA), and filter ash
(FA), which represent typical MSWI residues. Our findings indicate
that, irrespective of the residue type, a suite of membrane transporters,
porins, efflux pumps, and specific electron and cation transfer proteins
was notably upregulated. The upregulation of certain proteins involved
in anaerobic pathways suggested the development of a spontaneous microaerobic
environment, which minimally impacted the bioleaching efficiency.
Additionally, the adaptation was most efficient at half the target
FA concentration, marked by a significant increase in the detoxification
and efflux systems required by microorganisms to tolerate high heavy
metal concentrations. Given that metal recovery peaked at lower FA
concentrations for most metals of interest, further adaptation at
the level of protein expression may not be warranted for improved
bioleaching outcomes.

嗜酸硫杆菌属（Acidithiobacillus spp.）传统上一直被用于通过生物浸出（bioleaching）从矿物矿石中提取金属。近年来该工艺的应用范围已拓展至人工矿石，例如源自城市生活垃圾焚烧（MSWI）残渣的人工矿石。已有研究表明，微生物的适应性可提升生物浸出效率，因此本研究旨在探明铁氧化嗜酸硫杆菌（A. ferridurans）适应MSWI残渣过程中涉及的蛋白质。本研究采用数据非依赖采集-平行累积连续碎裂（data-independent acquisition-parallel accumulation serial fragmentation）技术，检测了铁氧化嗜酸硫杆菌DSM 583对三种典型MSWI残渣——底灰（BA）、炉灰（KA）及滤灰（FA）——的蛋白质组响应。研究结果显示，无论残渣类型如何，一系列膜转运蛋白、孔蛋白、外排泵以及特定的电子与阳离子转移蛋白均显著上调。部分参与厌氧途径的蛋白质表达上调，表明体系中形成了自发的微有氧环境，该环境对生物浸出效率的影响极小。此外，在目标滤灰浓度减半的条件下，微生物的适应性效果最佳，此时微生物耐受高浓度重金属所需的解毒系统与外排系统表达显著上调。鉴于多数目标金属的回收率在较低滤灰浓度下达到峰值，因此无需通过进一步调控蛋白质表达来优化生物浸出效果。