In vitro digestion of microplastics in human digestive system: Insights into particle morphological changes and chemical leaching.

Despite the well-reported occurrences and established pathways for microplastics (MPs) ingestion by humans, the eventual fate of these particles in the human gastrointestinal system is poorly understood. The present study tries to gain a better understanding of the fate of four common food-borne MPs, i.e. Polystyrene (PS), Polypropylene (PP), Low-density Polyethylene (LDPE), and Nylon, in a simulated in vitro human digestive system. Firstly, the changes in the physicochemical properties of 20-210 µm sized MPs as well as the leaching of chemicals were monitored using fluorescence microscopy, FTIR, and LC-QTOF-MS. Thereafter, the mass loss and morphological alterations in 3-4 mm sized MPs were observed after removing the organic matter. The interaction of PS and PP MPs with duodenal and bile juices manifested in a corona formation. The increase in surface roughness in PP MPs aligned with MP-enzyme dehydrogenation reactions and the addition of NO groups. A few fragments ranging from 30 to 250 µm, with negligible mass loss, were released during the MP digestion process. In addition, the leaching of compounds, e.g. capsi-amide, butanamide, and other plasticizers and monomers was also observed from MPs during digestion, and which may have the potential to accumulate and get absorbed by the digestive organs, and to subsequently impart toxic effects.

A tool for rapid, automated characterization of population epigenomics in plants.

Epigenetic variation in plant populations is an important factor in determining phenotype and adaptation to the environment. However, while advances have been made in the molecular and computational methods to analyze the methylation status of a given sample of DNA, tools to profile and compare the methylomes of multiple individual plants or groups of plants at high resolution and low cost are lacking. Here, we describe a computational approach and R package (sounDMR) that leverages the benefits of long read nanopore sequencing to enable robust identification of differential methylation from complex experimental designs, as well as assess the variability within treatment groups and identify individual plants of interest. We demonstrate the utility of this approach by profiling a population of Arabidopsis thaliana exposed to a demethylating agent and identify genomic regions of high epigenetic variability between individuals. Given the low cost of nanopore sequencing devices and the ease of sample preparation, these results show that high resolution epigenetic profiling of plant populations can be made more broadly accessible in plant breeding and biotechnology.