微塑料对鲫鱼生长、肝脏损伤和肠道微生物组成的影响

广泛存在于自然环境中的微塑料可能会危害水生生物的生长和健康，目前该方面的研究较少.以淡水杂食性鱼类鲫鱼作为研究对象，喂食不同微塑料浓度的鱼食进行为期30 d的食源暴露试验，分析微塑料对鲫鱼生长、肝脏损伤和肠道微生物组成的影响.结果表明，与对照组相比，各试验组中鲫鱼的身长没有明显变化，但低浓度组的鲫鱼体重显著增加，中浓度组和高浓度组的体重明显下降.低浓度组的鲫鱼肝脏组织基本正常，中浓度组和高浓度组的均出现了不同程度的肝组织异常现象，其中高浓度组的肝脏损伤最为严重.鲫鱼肠道中，变形菌门、梭杆菌门、厚壁菌门和拟杆菌门是门水平上的优势菌种，葡萄球菌属和劳尔氏菌属等致病菌在各试验组鲫鱼肠道中均有出现；α多样性结果表明高浓度组的鲫鱼肠道微生物菌群最为丰富；PCoA结果显示对照组和试验组的鲫鱼肠道微生物存在明显的聚类特征.

Effects of Microplastic Exposure on Crucian Growth, Liver Damage, and Gut Microbiome Composition

Microplastics (MPs), which are widely present in the natural environment, may be harmful to the growth and health of aquatic organisms, though studies in this area are lacking. In this study, the crucian carp (Carassius carassius), a type of omnivorous freshwater fish, was chosen as the target, which was fed with fish food containing different concentrations of MPs for a 30-day food exposure experiment to study the effects of MPs on crucian growth, liver damage, and gut microbiome composition. Compared with that in the control group, the body length of the crucians in the environmental groups did not change significantly. The weight of the crucians in the low PE-MPs group increased significantly, but the weight of crucians in the medium and high PE-MPs groups decreased markedly. The liver tissues of the low PE-MPs group of crucians were basically normal, whereas crucians in the medium and high PE-MPs groups had varying degrees of liver damage, and crucians in the high PE-MPs group had the most serious liver damage. At the phylum level, Proteobacteria, Fusobacteria, Firmicutes, and Bacteroides were the dominant species in the gut of the crucians. Pathogens such as Staphylococcus and Ralstonia were present in the crucian gut of environmental groups. Alpha diversity results showed that the gut microbiome of crucians in the high PE-MPs group was the most abundant. PCoA results indicated that the gut microbiome of crucians in the control and environmental groups had obvious clustering characteristics.