Study on the life maintenance mechanism of Eisenia fetida under low-density polyethylene stress: Based on path analysis and canonical correlation analysis

Exploring the Toxicity of Oxytetracycline in Earthworms (Eisenia fetida) Based on the Integrated Biomarker Response Method

Antibiotic contamination has become a global environmental issue of widespread concern, among which oxytetracycline contamination is very severe. In this study, earthworm (Eisenia fetida) was exposed to oxytetracycline to study its impact on the soil environment. The total protein (TP), catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), malondialdehyde (MDA), glutathione S-transferase (GST), and glutathione peroxidase (GPX) oxidative stress indicators in earthworms were measured, and the integrated biomarker response (IBR) approach was used to evaluate the toxic effect of oxytetracycline on earthworms. A Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) and a path analysis model were used to explore the physiological and metabolic processes of earthworms after stress occurs. The results showed that SOD, GPX, and GST play important roles in resisting oxytetracycline stress. In addition, stress injury showed a good dose-effect relationship, and long-term stress from pollutants resulted in the most serious damage to the head tissue of earthworms. These results provide a theoretical basis for understanding the toxic effect of oxytetracycline on soil animals, monitoring the pollution status of oxytetracycline in soil, and conducting ecological security risk assessment.

Deciphering survival strategies: Oxidative stress and microbial interplay in Eisenia fetida under tetracycline contamination

Soil contamination resulting from residual antibiotics presents a pressing need to understand the survival mechanisms of soil organisms in polluted environments. This study focused on Eisenia fetida, and tetracycline stress experiments were conducted in a controlled environment using sterile artificial soil. The stress concentration ranged from 0 to 600 mg/kg, and stress cycles lasted either 10 or 30 days. The objective of this study was to assess the effects of oxidative stress and the changes in microbial communities both within and outside the earthworms. A comprehensive mathematical model was developed to elucidate the responses of organisms following exposure to stress utilizing factor analysis, grey relational analysis, and hierarchical entropy weight analysis. Under tetracycline stress, the initial stage (1-3 days) exhibited a coordinated regulation of oxidative stress and microbial communities in the soil with the assistance of CAT and GPX enzymes. The subsequent stage (4-5 days) further emphasized the influence of soil microbial communities. A notable "feedback regulation" of soil microbial communities on oxidative stress was observed during the third stage (6-8 days). Earthworms maintained a metabolic balance in the fourth stage (9-10 days). In the long term, the stress-induced a self-detoxification mechanism within soil microbial communities, which collaborated with GPX to respond to oxidative stress.

A method to study the effects of combined stress of cadmium and microplastics on the acute toxicity of Eisenia fetida

The compound pollutants formed by microplastics and cadmium present a significant potential threat to the soil-based ecosystem, and it is urgent to carry out relevant ecotoxicological studies. However, the lack of appropriate test methods and scientific mathematical analysis models has restricted the progress of research. Based on an orthogonal test design, a ternary combined stress test was performed to study the effect of microplastics and cadmium on earthworms. This study used the particle size and concentration of microplastics as well as the concentration of cadmium as test factors. Using the improved factor analysis model and the TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) method, a new model was constructed according to the response surface methodology to analyze the acute toxic effects on earthworms under the combined stress of microplastics and cadmium. In addition, the model was tested in a soil-polluted environment. The results show that the model can perfectly integrate the spatiotemporal cross effects of the concentration and time of the applied stress, and the scientific data analysis process ensures the efficient development of ecotoxicological research in the actual compound pollution environment. Moreover, the results of the filter paper test and soil test showed that the equivalent toxicity ratio of cadmium concentration, microplastic concentration, and microplastic particle size to earthworms as 26:35:39 and 23:36:41, respectively. In terms of the interaction effect, a certain positive interaction was observed between the cadmium concentration and that of the microplastics and their particle size, while a negative interaction was observed between the concentration of microplastics and their particle size. This research provides a test basis and model reference for early monitoring of the health of contaminated soils and assessments of ecological safety and security.