First evidence of off-flavour haloanisoles production by dormant fungal spores in drinking water: Formation pattern, influencing factors and transcriptome analysis.

Autor: Shi Y; College of Environment and Resources, College of Carbon Neutrality, Zhejiang A & F University, Hangzhou, Zhejiang 311300, China., Ma X; College of Environment and Resources, College of Carbon Neutrality, Zhejiang A & F University, Hangzhou, Zhejiang 311300, China., Yu H; College of Environment and Resources, College of Carbon Neutrality, Zhejiang A & F University, Hangzhou, Zhejiang 311300, China., Xing L; College of Environment and Resources, College of Carbon Neutrality, Zhejiang A & F University, Hangzhou, Zhejiang 311300, China., Meng Y; College of Environment and Resources, College of Carbon Neutrality, Zhejiang A & F University, Hangzhou, Zhejiang 311300, China., Yin L; College of Environment and Resources, College of Carbon Neutrality, Zhejiang A & F University, Hangzhou, Zhejiang 311300, China., Zhou X; College of Environment and Resources, College of Carbon Neutrality, Zhejiang A & F University, Hangzhou, Zhejiang 311300, China; Sino-Spain Joint Laboratory for Agricultural Environment Emerging Contaminants of Zhejiang Province, Hangzhou, Zhejiang 311300, China; Eco-Environment & Health College, Zhejiang A & F University, Hangzhou, Zhejiang 311300, China. Electronic address: zhouxy1993@zafu.edu.cn.
Jazyk: angličtina
Zdroj: Journal of hazardous materials [J Hazard Mater] 2024 Nov 29; Vol. 484, pp. 136714. Date of Electronic Publication: 2024 Nov 29.
DOI: 10.1016/j.jhazmat.2024.136714
Abstrakt: Fungi are major producers of off-flavour haloanisoles (HAs) in drinking water supply systems. However, evidence of HA production by dormant fungal spores remains unclear. This study investigated the microbial O-methylation of dormant spores of a fungus Aspergillus sp. from drinking water treatment plants. Dormant spores were capable of O-methylating 2,4,6-trichlorophenol (2,4,6-TCP) to produce 2,4,6-trichloroanisole (2,4,6-TCA). A pronounced linear correlation was identified between the precursor load and the 2,4,6-TCA formation capability, with a function lg(y)= 0.542lg(x) - 4.28 (R 2 = 0.838). The effects of metal ions on fungal spore O-methylation were multifaceted and highly concentration-dependent. Natural organic matters could inhibit 2,4,6-TCA formation. NH 2 Cl presented higher efficacy than free chlorine in inhibiting spore O-methylation. However, O-methylation inhibition rates were lower than spore inactivation rates, suggesting spores in viable but non-culturable state still possessed partial ability to form 2,4,6-TCA. Transcriptome analysis revealed that 50 nM 2,4,6-TCP treatment had no impact on the spore's transcriptional profile, whereas 1 mM Cu 2+ treatment significantly inhibited O-methylation process by down-regulating genes involved in ATP generation. This study provides a first evidence that dormant fungal spores are capable of producing 2,4,6-TCA, raising concerns about the potential off-flavour risk and the development of targeted control strategies in drinking water systems.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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