Biological effects and differences on the gut microbiome of Galleria mellonella larvae consuming plastics

RUIZ BARRIONUEVO, JULIANA; VILANOVA-CUEVAS, BRAYAN; ALVAREZ, ANALÍA; CHALUP, ADRIANA; DE CRISTÓBAL, RICARDO; GALINDO-CARDONA, ALBERTO; MALIZIA, AGUSTINA; MONMANY GARZIA, A. CAROLINA; OCCHIONERO, MARÍA ANGÉLICA; GODOY-VITORINO, FILIPA; MARTÍN, EDUARDO

Congreso; ISME Lat 2021; 2021

Plastic pollution is a footprint of the Anthropocene that is evident in all types of ecosystems. The main polluting plastics are polyethylene, polypropylene and polystyrene. In the last decade, different studies have assessed the capacity of insect microbiota to degrade plastics. We evaluated the consumption of a variety of plastics by wax moth (Galleria mellonella) larvae, and its effects on the biology of the species and the diversity of their gut microorganisms. We performed diet trials with two (polyethylene, polystyrene) and four (polyethylene, polystyrene, bioriented polypropylene, silobag) plastics, registered their survival and times of development, and examined their gut microbiome through 16S and ITS sequencing. The larvae consumed all types of plastics and completed their development in all treatments, however the duration of the larval stage was shortened when consuming plastics. Gut bacterial communities were different in larvae consuming beeswax and plastics. At the phylum level, the most abundant were Proteobacteria (72.2%), Firmicutes (14.9%) and Bacteroidetes (7.9%). In addition, Fusobacteria were present almost exclusively on wax while Fibrobacteria were dominant only on plastics. In relation to fungi, we found Ascomycota (72.1%) and Basidiomycota (27.9%), with no clear differences between treatments. Beeswax had dominant bacteria composed by taxa within the Neisseriaceae family, the genera Fusobacterium, Actinobacillus, Alloprovotella, Streptococcus and Leptotrichia; and in plastics we found more dominant Pseudomonas sp J27 and Pseudomonas citronellolis. Plastic consumption shortens the development of G. mellonella larvae and affects their gut microbiome. This is the first evaluation of the multi-kingdom response of gut microbiota (bacteria and fungi) to plastic consumption in wax moth larvae. Further analysis of the biological impacts of plastic consumption in G. mellonella and the role of their gut microbiome is critical to evaluate the species potential for plastic biodegradation.