聚乙烯高效降解复合菌系的构建及其降解特性研究

Construction and degradation characteristics of high-efficiency polyethylene degrading composite microbial community

【目的】聚乙烯塑料的稳定性及与日俱增的使用量为生态环境带来严重“白色污染”,其风化形成的微塑料为生物健康安全带来严重威胁的难题亟待解决。【方法】通过选择与纯培养技术分离大蜡螟幼虫消化道内潜在的聚乙烯微生物降解资源,通过菌株比例复配构建高效降解复合菌系,通过质控回收评估其降解能力,使用光镜与扫描电镜验证其降解性能,通过红外光谱、凝胶渗透色谱、气质联用与液质联用等技术手段探究聚乙烯的微生物降解特性。【结果】共分离出13株可降解聚乙烯微生物;首次发现Debaryomyces hansenii具有高效降解聚乙烯的能力;构建出一组由真菌与细菌组成的聚乙烯高效降解复合菌系,相较于单菌复合菌系的降解性能提升了3.3倍,其降解效率高达0.9367 mg/d远高于现有研究水平;光镜与扫描电镜发现聚乙烯薄膜降解后表面存在生物膜附着痕迹与明显孔洞;红外光谱显示降解液中存在多个新官能团,凝胶渗透色谱结果显示降解后聚乙烯微塑料分子量降低;气质与液质联用结果表明降解液中出现了酰胺类、氨基酸类、烯烃类、醇类、酮醛类等生物活性成分,以及大分子烷烃类物质等。【结论】研究挖掘了聚乙烯的微生物降解资源,构建出了高效降解复合菌系,探究了微生物的降解特性,为聚乙烯的微生物降解提供了数据支撑与可行方案。

[Objective]The The stability of polyethylene plastics and the increasing usage pose a serious threat of“white pollution”to the ecological environment.The generated microplastics from its weathering poses a significant challenge to biological health and safety.These challenges are in need of urgent solution.[Method]Potential microbial degradation resources for polyethylene in the digestive tract of the greater wax moth larvae were isolated using pure cultivation techniques.An efficient degradation composite microbial community was constructed through the proportional combination of strains.The degradation capacity was assessed through quality control recovery,and its performance was validated by light microscopy and scanning electron microscopy.Microbial degradation characteristics of polyethylene were explored by techniques including infrared spectroscopy,gel permeation chromatography,gas chromatography-mass spectrometry,and liquid chromatography-mass spectrometry.[Result]Thirteen strains of polyethylene-degrading microorganisms were isolated.Debaryomyces hansenii was identified for the first time as having the ability to efficiently degrade polyethylene.A polyethylene efficient degradation composite microbial community composed of fungi and bacteria was established.Compared with single strains,the degradation performance of the composite microbial community increased by 3.3 times,with a degradation efficiency of 0.9367 mg/d,which significantly surpassed previous levels.Light microscopy and scanning electron microscopy revealed the presence of biofilm traces and noticeable pores on the surface of degraded polyethylene films.Infrared spectroscopy showed the presence of multiple new functional groups in the degradation solution,and gel permeation chromatography results indicated a reduction in the molecular weight of polyethylene microplastics after degradation.Gas and liquid chromatography-mass spectrometry results indicated the presence of bioactive components such as amides,amino acids,olefins,alcohols,ketones,and large-molecule alkanes in the degradation solution.[Conclusion]The study identified microbial degradation resources for polyethylene by constructing an efficient degradation composite microbial community,and it explored microbial degradation characteristics,thus providing data support and feasible solutions for the microbial degradation of polyethylene.