Department of Civil and Environmental Engineering , Stanford University , Stanford , California 94305-4020 , United States.
Institute for Environmental Genomics, Consolidated Core Laboratory, Department of Microbiology and Plant Biology, and School of Civil Engineering and Environmental Science , University of Oklahoma , Norman , Oklahoma 73019 , United States.
Environ Sci Technol. 2018 Jun 5;52(11):6526-6533. doi: 10.1021/acs.est.8b02301. Epub 2018 May 23.
Recent studies have demonstrated the ability for polystyrene (PS) degradation within the gut of mealworms ( Tenebrio molitor). To determine whether plastics may be broadly susceptible to biodegradation within mealworms, we evaluated the fate of polyethylene (PE) and mixtures (PE + PS). We find that PE biodegrades at comparable rates to PS. Mass balances indicate conversion of up 49.0 ± 1.4% of the ingested PE into a putative gas fraction (CO). The molecular weights ( M) of egested polymer residues decreased by 40.1 ± 8.5% in PE-fed mealworms and by 12.8 ± 3.1% in PS-fed mealworms. NMR and FTIR analyses revealed chemical modifications consistent with degradation and partial oxidation of the polymer. Mixtures likewise degraded. Our results are consistent with a nonspecific degradation mechanism. Analysis of the gut microbiome by next-generation sequencing revealed two OTUs ( Citrobacter sp. and Kosakonia sp.) strongly associated with both PE and PS as well as OTUs unique to each plastic. Our results suggest that adaptability of the mealworm gut microbiome enables degradation of chemically dissimilar plastics.
最近的研究表明，在黄粉虫（Tenebrio molitor）的肠道内，聚苯乙烯（PS）具有降解能力。为了确定塑料是否可能广泛易生物降解于黄粉虫体内，我们评估了聚乙烯（PE）和混合物（PE + PS）的命运。我们发现 PE 以与 PS 相当的速率进行生物降解。质量平衡表明，高达 49.0 ± 1.4%的摄入 PE 转化为一种假定的气体分数（CO）。在 PE 喂养的黄粉虫中，排泄出的聚合物残留物的分子量（M）下降了 40.1 ± 8.5%，而在 PS 喂养的黄粉虫中下降了 12.8 ± 3.1%。NMR 和 FTIR 分析显示出与聚合物降解和部分氧化一致的化学修饰。混合物同样降解。我们的结果与非特异性降解机制一致。通过下一代测序对肠道微生物组的分析显示，两个 OTU（Citrobacter sp. 和 Kosakonia sp.）与 PE 和 PS 强烈相关，并且与每种塑料都具有独特的 OTU。我们的结果表明，黄粉虫肠道微生物组的适应性使具有不同化学性质的塑料能够降解。
