Freshwater alga Raphidocelis subcapitata undergoes metabolomic changes in response to electrostatic adhesion by micrometer-sized nylon 6 particles

Abstract Nylon powders are a type of microplastic (MP) used in personal care products such as cosmetics and sunscreens. To determine the effects of nylon on freshwater microalgae, we investigated the effects of two types of micrometer-sized nylons, i.e., powdered nylon 6 (Ny6-P) and nylon 12 (Ny12), and four other micrometer-sized MPs, i.e., low-density polyethylene, polyethylene terephthalate, polystyrene, and ultra-high-molecular-weight polyethylene, on the microalga Raphidocelis subcapitata. The results showed that Ny6-P inhibited R. subcapitata growth more than the other MPs; R. subcapitata growth was inhibited by 54.2% with 6.25 mg/L Ny6-P compared with the control. Ny6-P in the culture media adhered R. subcapitata cells electrostatically, which disrupted growth and photosynthesis. Metabolomic analysis revealed that many metabolites related to the amino acid catabolic pathway and γ-glutamyl cycle were induced, which might reflect responses to avoid starvation and oxidative stress. Our study provides important information on the effects of Ny6-P on algae in freshwater environments.

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Freshwater alga Raphidocelis subcapitata undergoes metabolomic changes in response to electrostatic adhesion by micrometer-sized nylon 6 particles

Environmental Science and Pollution Research ◽

10.1007/s11356-021-15300-8 ◽

2021 ◽

Author(s):

Satomi Mizukami-Murata ◽

Yuji Suzuki ◽

Kensuke Sakurai ◽

Hiromasa Yamashita

Keyword(s):

Photosynthetic Activity ◽

Culture Media ◽

Nylon 6 ◽

Catabolic Pathway ◽

Freshwater Microalgae ◽

Raphidocelis Subcapitata ◽

Nylon 12 ◽

Ultra High Molecular Weight ◽

And Oxidative Stress ◽

Electrostatic Adhesion

AbstractNylon powders are a type of microplastic (MP) used in personal care products such as cosmetics and sunscreens. To determine the effects of nylon polymers on freshwater microalgae, we investigated the effects of two types of micrometer-sized nylon polymers, i.e., powdered nylon 6 (Ny6-P) and nylon 12 (Ny12), and four other micrometer-sized MPs, i.e., low-density polyethylene, polyethylene terephthalate, polystyrene, and ultra-high-molecular-weight polyethylene, on the microalga Raphidocelis subcapitata. The results showed that Ny6-P inhibited R. subcapitata growth more than the other MPs; R. subcapitata growth was inhibited by 54.2% with 6.25 mg/L Ny6-P compared with the control. Ny6-P in the culture media adhered to R. subcapitata cells electrostatically, which may have disrupted growth and photosynthetic activity. Metabolomic analysis revealed that many metabolites related to the amino acid catabolic pathway and γ-glutamyl cycle were induced, which might trigger responses to avoid starvation and oxidative stress. Our study provides important information on the effects of Ny6-P on algae in freshwater environments.

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Assessing the Conversion of Various Nylon Polymers in the Hydrothermal Liquefaction of Macroalgae

Environments ◽

10.3390/environments8040034 ◽

2021 ◽

Vol 8 (4) ◽

pp. 34

Author(s):

Sukanya Hongthong ◽

Hannah S. Leese ◽

Michael J. Allen ◽

Christopher J. Chuck

Keyword(s):

Nylon 6 ◽

Hydrothermal Liquefaction ◽

Marine Macroalgae ◽

Fishing Gear ◽

Third Generation ◽

Conventional Agriculture ◽

Fucus Serratus ◽

Nylon 12 ◽

Fuels And Chemicals ◽

Real Challenge

Marine macroalgae offers a promising third generation feedstock for the production of fuels and chemicals, avoiding competition with conventional agriculture and potentially helping to improve eutrophication in seas and oceans. However, an increasing amount of plastic is distributed into the oceans, and as such contaminating macroalgal beds. One of the major plastic contaminants is nylon 6 derived from discarded fishing gear, though an increasing amount of alternative nylon polymers, derived from fabrics, are also observed. This study aimed to assess the effect of these nylon contaminants on the hydrothermal liquefaction of Fucus serratus. The hydrothermal liquefaction (HTL) of macroalgae was undertaken at 350 °C for 10 min, with a range of nylon polymers (nylon 6, nylon 6/6, nylon 12 and nylon 6/12), in the blend of 5, 20 and 50 wt.% nylon to biomass; 17 wt.% biocrude was achieved from a 50% blend of nylon 6 with F. serratus. In addition, nylon 6 completely broke down in the system producing the monomer caprolactam. The suitability of converting fishing gear was further demonstrated by conversion of actual fishing line (nylon 6) with the macroalgae, producing an array of products. The alternative nylon polymer blends were less reactive, with only 54% of the nylon 6/6 breaking down under the HTL conditions, forming cyclopentanone which distributed into the biocrude phase. Nylon 6/12 and nylon 12 were even less reactive, and only traces of the monomer cyclododecanone were observed in the biocrude phase. This study demonstrates that while nylon 6 derived from fishing gear can be effectively integrated into a macroalgal biorefinery, alternative nylon polymers from other sectors are too stable to be converted under these conditions and present a real challenge to a macroalgal biorefinery.

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Gut microbiota accelerates cisplatin-induced acute liver injury associated with robust inflammation and oxidative stress in mice

Journal of Translational Medicine ◽

10.1186/s12967-021-02814-5 ◽

2021 ◽

Vol 19 (1) ◽

Author(s):

Shenhai Gong ◽

Yinglin Feng ◽

Yunong Zeng ◽

Huanrui Zhang ◽

Meiping Pan ◽

...

Keyword(s):

Oxidative Stress ◽

16S Rrna ◽

Gut Microbiota ◽

Gene Sequencing ◽

16S Rrna Gene Sequencing ◽

Rrna Gene ◽

Metabolomic Analysis ◽

Rrna Gene Sequencing ◽

And Oxidative Stress

Abstract Background Gut microbiota has been reported to be disrupted by cisplatin, as well as to modulate chemotherapy toxicity. However, the precise role of intestinal microbiota in the pathogenesis of cisplatin hepatotoxicity remains unknown. Methods We compared the composition and function of gut microbiota between mice treated with and without cisplatin using 16S rRNA gene sequencing and via metabolomic analysis. For understanding the causative relationship between gut dysbiosis and cisplatin hepatotoxicity, antibiotics were administered to deplete gut microbiota and faecal microbiota transplantation (FMT) was performed before cisplatin treatment. Results 16S rRNA gene sequencing and metabolomic analysis showed that cisplatin administration caused gut microbiota dysbiosis in mice. Gut microbiota ablation by antibiotic exposure protected against the hepatotoxicity induced by cisplatin. Interestingly, mice treated with antibiotics dampened the mitogen-activated protein kinase pathway activation and promoted nuclear factor erythroid 2-related factor 2 nuclear translocation, resulting in decreased levels of both inflammation and oxidative stress in the liver. FMT also confirmed the role of microbiota in individual susceptibility to cisplatin-induced hepatotoxicity. Conclusions This study elucidated the mechanism by which gut microbiota mediates cisplatin hepatotoxicity through enhanced inflammatory response and oxidative stress. This knowledge may help develop novel therapeutic approaches that involve targeting the composition and metabolites of microbiota.

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