title: Biodegradation and Mineralization of Polystyrene by Plastic-Eating Mealworms: Part 2. Role of Gut Microorganisms.
abstract: The role of gut bacteria of mealworms (the larvae of Tenebrio molitor Linnaeus) in polystyrene (PS) degradation was investigated. Gentamicin was the most effective inhibitor of gut bacteria among six antibiotics tested. Gut bacterial activities were essentially suppressed by feeding gentamicin food (30 mg/g) for 10 days. Gentamicin-feeding mealworms lost the ability to depolymerize PS and mineralize PS into CO2, as determined by characterizing worm fecula and feeding with (13)C-labeled PS. A PS-degrading bacterial strain was isolated from the guts of the mealworms, Exiguobacterium sp. strain YT2, which could form biofilm on PS film over a 28 day incubation period and made obvious pits and cavities (0.2-0.3 mm in width) on PS film surfaces associated with decreases in hydrophobicity and the formation of C-O polar groups. A suspension culture of strain YT2 (10(8) cells/mL) was able to degrade 7.4 ± 0.4% of the PS pieces (2500 mg/L) over a 60 day incubation period. The molecular weight of the residual PS pieces was lower, and the release of water-soluble daughter products was detected. The results indicated the essential role of gut bacteria in PS biodegradation and mineralization, confirmed the presence of PS-degrading gut bacteria, and demonstrated the biodegradation of PS by mealworms.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
authors.forename: Jun
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Civil and Environmental Engineering, William & Cloy Codiga Resource Recovery Research Center, Center for Sustainable Development & Global Competitiveness, Stanford University , Stanford, California 94305-4020, United States.
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Wu
authors.affiliation: Shenzhen Key Laboratory of Bioenergy, BGI-Shenzhen , Shenzhen, Guangdong 518083, People's Republic of China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Zhao
authors.forename: Yiling
authors.initials: Y
authors.lastname: Song
authors.forename: Longcheng
authors.initials: L
authors.lastname: Gao
authors.affiliation: Shenzhen Key Laboratory of Bioenergy, BGI-Shenzhen , Shenzhen, Guangdong 518083, People's Republic of China.
authors.forename: Ruifu
authors.initials: R
authors.lastname: Yang
authors.forename: Lei
authors.initials: L
authors.lastname: Jiang
mesh_terms: D000818:Animals; D001673:Biodegradation, Environmental; D018441:Biofilms; D004435:Eating; D004755:Enterobacteriaceae / Q000187:drug effects / Q000254:growth & development; D000069196:Gastrointestinal Microbiome / Q000187:drug effects / Q000502:physiology*; D005839:Gentamicins / Q000494:pharmacology; D007814:Larva / Q000382:microbiology; D008970:Molecular Weight; D010969:Plastics / Q000378:metabolism; D011137:Polystyrenes / Q000737:chemistry / Q000378:metabolism*; D013712:Tenebrio / Q000187:drug effects / Q000382:microbiology* / Q000502:physiology
chemical_list: D005839:Gentamicins; D010969:Plastics; D011137:Polystyrenes