大麦虫及其肠道微生物对聚乙烯的生物降解

【背景】废旧塑料聚乙烯因具有较高的化学惰性，不易被自然降解而形成长期污染。【目的】探究聚乙烯泡沫塑料对大麦虫生长发育的影响，为大麦虫作为降解聚乙烯泡沫塑料的昆虫推广提供理论依据。【方法】以大麦虫幼虫为研究对象，选用常见的泡沫塑料(聚乙烯)，采用4种不同的饲喂方式T1 (麦麸)、T2 (泡沫塑料)、T3 (泡沫塑料+麦麸)、T4 (不饲喂)进行驯化，处理30 d后对大麦虫进行解剖，取肠道内容物于LB培养基中进行富集培养，将富集培养后的菌液加入以聚乙烯(polyethylene,PE)为唯一碳源的LCFBM培养基进行选择性培养，从中筛选分离得到对PE塑料有降解能力的菌株。【结果】取食泡沫塑料30d后，与单一饲喂PE相比，麦麸和PE混合饲喂后大麦虫幼虫的存活率为76%。采用傅里叶变换红外光谱检测发现虫粪组分中主要官能团中峰值明显变化，表明PE长链有断裂现象，并从肠道中分离得到3株可以对PE薄膜边缘造成明显侵蚀的菌株。【结论】大麦虫可取食并消化PE塑料，其肠道内的微生物对PE塑料的降解起到关键作用，研究结果为塑料污染的生物降解提供了科学证据。

Biodegradation of polyethylene by Zophobas atratus and its gut microorganisms

Background] Waste plastic polyethylene (PE) is refractory due to its high chemical inertness, resulting in long-term pollution. Objective] To investigate the effects of common plastic foam (PE) on the growth and development of Zophobas atratus and provide a theoretical basis for the application of Z. atratus as an insect in the degradation of PE plastic foam. Methods] Z. atratus larvae were fed with four different diets: T1 (wheat bran), T2 (plastic foam), T3 (plastic foam+wheat bran), and T4 (no diet). After 30 days of feeding, the larvae were dissected and the gut contents were enriched in LB medium. The obtained culture was added to the medium with PE as the only carbon source for selective culture, from which the strains capable of degrading PE plastics were isolated. Results] After feeding on plastic foam and wheat bran for 30 days, the Z. atratus larvae showed a survival rate of 76%. Fourier transform infrared (FTIR) spectroscopy detected significant changes in the peaks corresponding to the main functional groups of compounds in the feces, which indicated a break in the long chains of PE. Three strains causing significant erosion on the edges of PE films were isolated from the gut. Conclusion] Z. atratus can feed on and digest PE plastics, and the gut microorganisms play a key role in the degradation of PE plastics. The findings of this study provide scientific evidence for the bioremediation of plastic pollution.