Researcher(s)
- Amelia Owen, Chemical Engineering, University of Delaware
Faculty Mentor(s)
- Mark Blenner, Chemical and Biomolecular Engineering, University of Delaware
Abstract
Low-density polyethylene (LDPE) is a widely used plastic due to its beneficial properties and cost-effectiveness, making it one of the most common types of plastic found in landfills. However, its resistance to biodegradation makes it a growing environmental concern. Recent studies have shown that Tenebrio molitor (mealworms) can survive on an LDPE-only diet, and may contribute to plastic degradation through their microbial activity. Bacteriophages, viruses that infect bacteria, are present in the microbiome of mealworms but have not been well explored, despite their potential role in the bacterial communities responsible for breaking down plastic. This project focuses on refining the methods to isolate and purify viral DNA from mealworm gut samples while addressing pigment and polyphenolic contamination that interfere with downstream extraction and PCR. In this way, we will be able to better investigate how phage may influence the gut microbiome of mealworms fed LDPE, and how they affect plastic-degrading bacteria.
Mealworms were fed diets of bran or LDPE, and gut samples were collected over the feeding period. Following homogenization, samples were passed through a series of filters to enrich the viral fraction and remove larger-sized tissues and fat deposits. Several approaches were evaluated to improve viral DNA purification from mealworm gut samples. These included pigment-reduction treatments using PVP and PVPP, as well as viral concentration methods using Amicon® Ultra centrifugal filters and PEG-based phage pelleting. Preliminary experiments indicated that Amicon filtration and PVP/PVPP treatments did not effectively remove pigment, resulting in failed amplification of the bacterial 16S rRNA gene. This prompted the development of a PEG phage pelleting protocol. The effectiveness of each purification strategy is being evaluated based on pigment removal and viral DNA isolation. Establishing an optimized procedure will support future sequencing studies aimed at understanding the role of bacteriophages in plastic-degrading microbial communities.