Background: Currently, nanotechnology and nanoparticles have quickly emerged and have gained the attention of scientists due to their massive applications in environmental sectors. However, these environmental applications of silver nanoparticles potentially cause serious effects on terrestrial and aquatic organisms. In the current study, freshwater fish C. carpio were exposed to blood-mediated silver nanoparticles for toxicity, mortality, bioaccumulation, and histological alterations. Silver nanoparticles were fabricated using animal blood serum and their toxic effect was studied against common carp fish at different concentrations levels (0.03, 0.06, and 0.09 mg/L). Results: The findings have revealed a little influence of blood-induced silver nanoparticles on fish behavior at the highest concentration (0.09 mg/L). However, bioaccumulation of blood-mediated silver nanoparticles was reported in different organs of fish. Maximum bioaccumulation of silver nanoparticles was reported in the liver, followed by the intestine, gills, and muscles. Furthermore, the findings have shown that the bioaccumulation of silver nanoparticles led to histopathological alterations; including damaged structure of gill tissue and have caused necrosis. It is summarized that histopathological alteration in gill and intestine mostly occurred by the highest concentration of blood-induced silver nanoparticles (0.09 mg/L). Conclusion: This study provides evidence of the silver nanoparticles influence on aquatic life; however, further systematic studies are crucial to access the effects of AgNPs on aquatic life.

In this study, we compared the microbial communities colonising ancient cave wall paintings of the Mogao Grottoes exhibiting signs of biodeterioration. Ten samples were collected from five different caves built during different time periods and analysed using culture-independent and culture-dependent methods. The clone library results revealed high microbial diversity, including the bacterial groups Firmicutes, Proteobacteria, Actinobacteria, Acidobacteria, Cyanobacteria, Bacteroidetes, Gemmatimonadetes, Planctomycetes, and Chloroflexi and the fungal groups Euascomycetes, Dothideomycetes, Eurotiomycetes, Sordariomycetes, Saccharomycetes, Plectomycetes, Pezizomycetes, Zygomycota, and Basidiomycota. The bacterial community structures differed among the samples, with no consistent temporal or spatial trends. However, the fungal community diversity index correlated with the building time of the caves independent of environmental factors (e.g., temperature or relative humidity). The enrichment cultures revealed that many culturable strains were highly resistant to various stresses and thus may be responsible for the damage to cave paintings in the Mogao Grottoes.