Changes in the gut microbiome and enzymatic profile of Tenebrio molitor larvae biodegrading cellulose, polyethylene and polystyrene waste

• Published in: Environmental pollution (1987) 2020-01, Vol.256, p.113265-113265, Article 113265
• Main Authors: Przemieniecki, Sebastian W., Kosewska, Agnieszka, Ciesielski, Sławomir, Kosewska, Olga
• Format: Article
• Language: English
• Subjects: Animal Feed; Animals; beta-Glucosidase - metabolism; Biodegradation, Environmental; Cellulose - metabolism; Gastrointestinal Microbiome - drug effects; Gastrointestinal Tract - metabolism; Gastrointestinal Tract - microbiology; Hydrolytic enzymes; Insects digestive system; Larva - metabolism; Mealworm; Metagenome; Microbiota - drug effects; Plastics degradation; Polyethylene - metabolism; Polystyrenes - metabolism; Tenebrio - drug effects; Tenebrio - enzymology; Tenebrio - microbiology
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2019.113265

Recent studies have demonstrated the ability of mealworm (Tenebrio molitor) for plastic degradation. This study is focused on changes in microbiome structure depending on diets. Microbial community obtained from oat and cellulose diet formed similar group, two kinds of polyethylene formed another group, while polystyrene diet showed the highest dissimilarity. The highest relative abundance of bacteria colonizing gut was in PE-oxodegradable feeding, nevertheless all applied diets were higher in comparison to oat. Dominant phyla consisted of Proteobacteria, Bacteroides, Firmicutes and Actinobacteria, however after PS feeding frequency in Planctomycetes and Nitrospirae increased. The unique bacteria characteristic for cellulose diet belonged to Selenomonas, while Pantoea were characteristic for both polyethylene diets, Lactococcus and Elizabethkingia were unique for each plastic diet, and potential diazotropic bacteria were characteristic for polystyrene diet (Agrobacterium, Nitrosomonas, Nitrospira). Enzymatic similarity between oatmeal and cellulose diets, was shown. All three plastics diet resulted in different activity in both, digestive tract and bacteria. The enzymes with the highest activity were included phosphatases, esterases, leucine arylamidase, β-galactosidase, β-glucuronidase, α-glucosidase, β-glucosidase, chitinase, α-mannosidase and α-fucosidase. The activity of digestive tract was stronger than cultured gut bacteria. In addition to known polyethylene degradation methods, larvae may degrade polyethylene with esterase, cellulose and oatmeal waste activity is related with the activity of sugar-degrading enzymes, degradation of polystyrene with anaerobic processes and diazotrophs. [Display omitted] •Mealworms gut microbiota is responsible for the utilization of plastics.•Mealworm larvae tolerate a diet based on cellulose and plastics as well as cereal.•Depending on the diet, the abundance of particular groups of bacteria changes.•Diets modifies the activity of hydrolytic enzymes secreted by the digestive system.•During the utilization of polystyrene, increase abundance of diazotrophic bacteria.