Plastic-eating superworms - Investigating plastic degrading abilities of Zophobas morio larvae gut microbiomes
Student/in: Dominick Justin Mündges, BSc
Termin: 16.06.2025, 09:30 Uhr
Ort: Hörsaal D
1. Prüfer/in: Univ.-Prof. Mag. Christian Rinke, PhD
2. Prüfer/in: Ass.-Prof. Dr. Luis Miguel Rodriguez Rojas
Vorsitzende/r: Priv.-Doz. Mag. Dr. Sabine Podmirseg
Interessierte Kolleginnen und Kollegen sind herzlich willkommen!
Abstract
This project investigates the plastic-degrading potential of the gut microbiome of Zophobas morio larvae (“superworms”), focusing on polystyrene (PS) and polyethylene (PE). Following controlled feeding trials with plastic-based diets, DNA and RNA were extracted from larval gut samples to identify microbial taxa and enzymes potentially involved in polymer degradation. To validate findings, enrichment cultures were established using minimal media with ground PS or PE as the sole carbon source. Proteins from these cultures were extracted, sequenced, and analyzed. Bioinformatic analyses of metangenomic DNA and metatranscriptomic RNA sequencing data from feeding trials were compared to elucidate enzymatic pathways and microbial players in plastic degradation. Hidden Markov Models (HMM) were used to compare identified genes to known plastic-degrading proteins. Plastic degradation in fecal samples was assessed via Fourier-transform infrared spectroscopy (FTIR), which detects changes in molecular bonds. Feeding trials revealed higher survival rates in plastic-fed larvae compared to starvation controls, suggesting metabolic utilization of polymer-bound carbon. Metagenomic analyses revealed shifts in microbial communities between treatment groups. HMM analysis showed a higher number of hits to known plastic-degrading proteins in DNA from plastic-fed groups. Metagenome-assembled genomes (MAGs) revealed microbial taxa with varying numbers of HMM hits, identifying promising candidates for plastic degradation activity. RNA-seq expression profiles of known plastic degrading genes varied across treatment groups, suggesting transcriptional responses to plastic exposure. FTIR analysis did not reveal significant differences between untreated and fecal plastic samples, potentially due to contamination by gut content of fecal samples. For future experiments, FTIR measurements can be enhanced by washing fecal plastic samples. Increasing RNA sequencing depth can help to better understand plastic degradation in superworm guts on a transcriptomic level and thereby identify key proteins and microbes responsible. The results of this study provide a foundation for identifying enzymes and microbial pathways involved in plastic degradation and inform future efforts in biotechnological applications targeting treatment of plastic wastes.