[en] Nonylphenol (NP), ubiquitously detected as the degradation product of nonionic surfactants nonylphenol polyethoxylates, has been reported as an endocrine disrupter. However, most pure microorganisms can degrade only limited species of NP with low degradation efficiencies. To establish a microbial consortium that can effectively degrade different forms of NP, in this study, we isolated a facultative microbial consortium NP-M2 and characterized the biodegradation of NP by it. NP-M2 could degrade 75.61% and 89.75% of 1000 mg/L NP within 48 h and 8 days, respectively; an efficiency higher than that of any other consortium or pure microorganism reported so far. The addition of yeast extract promoted the biodegradation more significantly than that of glucose. Moreover, surface-active compounds secreted into the extracellular environment were hypothesized to promote high-efficiency metabolism of NP. The detoxification of NP by this consortium was determined. The degradation pathway was hypothesized to be initiated by oxidization of the benzene ring, followed by step-wise side-chain biodegradation. The bacterial composition of NP-M2 was determined using 16S rDNA library, and the consortium was found to mainly comprise members of the Sphingomonas, Pseudomonas, Alicycliphilus, and Acidovorax genera, with the former two accounting for 86.86% of the consortium. The high degradation efficiency of NP-M2 indicated that it could be a promising candidate for NP bioremediation in situ. - Highlights: • Consortium NP-M2 could degrade and detoxify nonylphenol effectively. • The addition of organic matter promoted biodegradation. • Secreted surface-active compounds might facilitate biodegradation. • The degradation pathway for NP by NP-M2 was proposed. • Bacterial composition was analyzed using the 16S rDNA library. - Isolation and characterization analysis of an efficient nonylphenol-degrading bacterial consortium with an efficiency higher than that of other reported microorganisms.

[en] Highlights: ●Single IMI/DIN (~50 ng/g soil) disturbed TCA/urea cycle and the related metabolites. ●IMI initiated antioxidation first then energy production, a reverse order for DIN. ●IMI-exposed worm induced UDP-glucuronate to generate IMI-urea for detoxification. ●DIN-exposed worm produced carnosine and nicotinate-like compounds to relieve stress. ●Worms upon dual exposure used amino acids to rebalance disturbed energy metabolism. Metabolomic responses of earthworms to neonicotinoids are important for understanding their molecular-level toxicity and assessing their ecological risks, but little is known until now. We investigated impact of imidacloprid (IMI, 52.6 ng/g) and dinotefuran (DIN, 52.5 ng/g) on Eisenia fetida metabolomics under single- and dual-compound exposure scenarios for one to four weeks. Dissimilar metabolites and anti-stress strategies were found for different neonicotinoids and exposure scenarios. Specifically, IMI exposure first increased myo-inositol and UDP-glucuronate associated with transmembrane absorption and transformation to IMI-urea, and then increased glutathione and fourteen amino acids (TCA cycle precursors) to resist stress and replenish energy. In contrast, worms exposed to DIN first prepared TCA cycle intermediates from glucosamine-6-phosphate and amino acids, suppressed urea cycle and DIN transformation, and then alleviated oxidative stress by increasing carnosine, nicotinate-D-ribonucleotide and nicotinamide-β-riboside. Dual exposure increased four eicosanoids by 1.6–1.9-fold, possibly associated with membrane lipid peroxidation; the amino acids consumed to balance the energy metabolism exhibited a wave-like pattern. This study first systematically revealed the compound/time/exposure scenario- dependent effects of trace neonicotinoids on earthworm metabolomics and advanced the understanding of their action modes. Neonicotinoid transformation was closely related to worms’ metabolic profiles, providing important insights in contaminant fate in soil ecosystems.

[en] Highlights: • NPEOs-degrading Sphingomonas sp. Y2 was immobilized on PD-IONPs yielding Y2-PD-IONPs. • Y2-PD-IONPs have the advantages of good degradation efficiency, stability, reusability, and easy separation. • Y2-PD-IONPs retained over 70.0% degradation activity after 6 cycles of utilization. • Y2-PD-IONPs can be used for biodegradation of NPEOs in simulated-textile wastewater. In this study, the efficiency of the nonylphenol polyethoxylates (NPEOs)-degrading bacterium Sphingomonas sp. strain Y2 was evaluated, which was immobilized by a novel system composed of polydopamine (PD)-coated Fe₃O₄ iron nanoparticles (IONPs). The PD-IONPs, with a distinct core-shell structure, relatively uniform size, and high saturation magnetization, were prepared for Y2 immobilization. The performance of Y2 was unaffected by this novel immobilization method, exhibiting 79.5% and 99.9% of NPEOs (500 ppm) degradation efficiency at day 1 and 2, respectively. Furthermore, separation and recycling were more readily achieved for immobilized cells as compared to free cells. Immobilized cells retained over 70% of the original degradation activity after 6 cycles of utilization. These results suggest that Y2-PD-IONPs can be potentially used for NPEOs-contaminated wastewater bioremediation.