Microbial Succession on Microplastics in Wastewater Treatment Plants: Exploring the Complexities of Microplastic-Microbiome Interactions.

Despite some effectiveness of wastewater treatment processes, microplastics accumulate in sewage sludge and their further use may contribute to the release of plastic microplastics into the environment. There is an urgent need to reduce the amount of microplastics in sewage sludge. Plastic particles serve as solid substrates for various microorganisms, promoting the formation of microbial biofilms with different metabolic activities. The biofilm environment associated with microplastics will determine the efficiency of treatment processes, especially biological methods, and the mechanisms of organic compound conversion. A significant source of microplastics is the land application of sewage sludge from wastewater treatment plants. The detrimental impact of microplastics affects soil enzymatic activity, soil microorganisms, flora, fauna, and plant production. This review article summarizes the development of research related to microplastics and discusses the issue of microplastic introduction from sewage sludge. Given that microplastics can contain complex composite polymers and form a plastisphere, further research is needed to understand their potential environmental impact, pathogenicity, and the characteristics of biofilms in wastewater treatment systems. The article also discusses the physicochemical properties of microplastics in wastewater treatment plants and their role in biofilm formation. Then, the article explained the impact of these properties on the possibility of the formation of biofilms on their surface due to the peculiar structure of microorganisms and also characterized what factors enable the formation of specific plastisphere in wastewater treatment plants. It highlights the urgent need to understand the basic information about microplastics to assess environmental toxicity more rationally, enabling better pollution control and the development of regulatory standards to manage microplastics entering the environment.

Analysis of Prussian carp (Carassius gibelio B.) oocytes under the influence of Roundup® herbicide.

The aim of this study was to investigate the effect of Roundup® herbicide on the maturation of Prussian carp oocytes under laboratory conditions. The Prussian carp is currently one of the most common fish species in Polish freshwater ichthyofauna. For the investigation, oocytes from five sexually mature female Prussian carp were used, segmented into three groups, and incubated for 24 h in Cortland's saline, treated with varied concentrations of the herbicide Roundup® (0 ng - control, R1 - 10 ng/ml, and R2 - 100 ng/ml). Subsequent to this period, assays were performed using the prepared plates to determine the level of 17α,20ß-dihydroxyprogesterone (17α,20ß-P) utilizing the standard ELISA technique. In determining the 17α,20ß-P via ELISA, the medium was extracted from each tested oocyte group. Oocyte maturity was assessed through preservation in serra fluid, and, to categorize the maturity stage of the oocytes utilizing a four-point scale - contingent upon the nucleus's position - the formerly preserved oocytes were dehydrated and subsequently analyzed. A contrast was noted in the percentage of oocytes at varied stages between the control group and the experimental groups. Specifically, a higher concentration of Roundup® (100 ng/ml) accelerated to expedite the initial migration of the nucleus in oocytes. In conclusion, the obtained results show the adverse effect of Roundup® on hormonal regulation and maturation in Prussian carp oocytes.