Biodegradation and Mineralization of Polystyrene by Plastic-Eating Mealworms: Part 1. Chemical and Physical Characterization and Isotopic Tests

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• 作者：Yu Yang ; Jun Yang ; Wei-Min Wu ; Jiao Zhao ; Yiling Song ; Longcheng Gao ; Ruifu Yang ; Lei Jiang
• 刊名：Environmental Science & Technology
• 出版年：2015
• 出版时间：October 20, 2015
• 年：2015
• 卷：49
• 期：20
• 页码：12080-12086
• 全文大小：418K
• ISSN：1520-5851

文摘

Polystyrene (PS) is generally considered to be durable and resistant to biodegradation. Mealworms (the larvae of Tenebrio molitor Linnaeus) from different sources chew and eat Styrofoam, a common PS product. The Styrofoam was efficiently degraded in the larval gut within a retention time of less than 24 h. Fed with Styrofoam as the sole diet, the larvae lived as well as those fed with a normal diet (bran) over a period of 1 month. The analysis of fecula egested from Styrofoam-feeding larvae, using gel permeation chromatography (GPC), solid-state ¹³C cross-polarization/magic angle spinning nuclear magnetic resonance (CP/MAS NMR) spectroscopy, and thermogravimetric Fourier transform infrared (TG鈥揊TIR) spectroscopy, substantiated that cleavage/depolymerization of long-chain PS molecules and the formation of depolymerized metabolites occurred in the larval gut. Within a 16 day test period, 47.7% of the ingested Styrofoam carbon was converted into CO₂ and the residue (ca. 49.2%) was egested as fecula with a limited fraction incorporated into biomass (ca. 0.5%). Tests with 伪 ¹³C- or 尾 ¹³C-labeled PS confirmed that the ¹³C-labeled PS was mineralized to ¹³CO₂ and incorporated into lipids. The discovery of the rapid biodegradation of PS in the larval gut reveals a new fate for plastic waste in the environment.