Hydroxyl radical mediated extracellular degradation of tetracycline under aerobic and anaerobic conditions stimulated by bio-FeS nanoparticles

• Published in: Journal of hazardous materials 2024-10, Vol.478, p.135450, Article 135450
• Main Authors: Lan, Huixia, Li, Ke, Cao, Qiliang, Liang, Qiaochu, Lin, Yecheng, Jegatheesan, Veeriah, Yan, Binghua, Zhang, Heng, Zhang, Yang
• Format: Article
• Language: English
• Subjects: Aerobiosis; Anaerobiosis; Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - metabolism; Biodegradation; Biodegradation, Environmental; Bioparticles; Extracellular electron transport; Ferrous Compounds; Hydroxyl Radical - chemistry; Hydroxyl Radical - metabolism; Hydroxyl radical production; Iron - chemistry; Iron - metabolism; Metal Nanoparticles - chemistry; Nanoparticles - chemistry; Tetracycline - chemistry; Tetracycline - metabolism; Tetracycline degradation; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - metabolism
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2024.135450

The extracellular degradation of antibiotics facilitated by bio-nanoparticles is significant in the field of waste valorization. Among different bio-nanoparticles, bio-FeS nanoparticles stand out for their convenient and cost-effective synthesis. Nevertheless, there is a lack of understanding regarding the extracellular degradation of pollutants driven by bio-FeS nanoparticles. Hence, this study aimed to investigate the role of bio-FeS nanoparticles in the extracellular degradation of tetracycline under aerobic and anaerobic conditions. The findings demonstrated that bio-FeS nanoparticles generated hydroxyl radical (·OH), which significantly contributes to the degradation of tetracycline in both aerobic and anaerobic environments. The production of ·OH in anaerobic conditions was primarily attributed to the limited formation of FeS2 during the biosynthesis of nanoparticles, which was very different from aerobic conditions. The bio-FeS nanoparticles facilitated extracellular electron transport by promoting electron shuttles and Fe(II)/Fe(III) cycling, resulting in the continuous production of ·OH. The degradation pathways showed differences under aerobic and anaerobic conditions, with intermediates exhibiting higher toxicity and greater cellular damage under aerobic conditions. However, in anaerobic conditions, bio-FeS nanoparticles enabled the successful integration of intracellular and extracellular degradation of tetracycline. This research proposed a new avenue for biocatalysis and environmental remediation. [Display omitted] •Bio-FeS nanoparticles enable the extracellular degradation of antibiotics.•Bio-FeS nanoparticles were synthesized using Bacillus cereus to degrade tetracycline.•Bio-FeS nanoparticles promoted cytochrome c and Fe(II)/Fe(III) cycling.•Limited FeS2 formation led to·OH production under anaerobic conditions.•Bio-FeS nanoparticles offer the potential for treating wastewater and biocatalysis.