生态环境学报2017，Vol.26Issue(4)：681-686,6.DOI:10.16258/j.cnki.1674-5906.2017.04.020
一株聚乙烯降解菌的筛选及其降解特性研究
Screening A Polyethylene Degrading Strain and Study on the Degradation Characteristics
摘要
Abstract
This is a study about the solution to degrade the refractorypolyethylene plastic in natural environmental .We disintegrated a strain from soil that could degrade polyethylene plastic. After screening and purification, we began our experiments by doing physiological and biochemical identification, 16S rDNA sequence cloning and constructing a phylogeny tree. In this case, polyeth-ylene powder (relative molecular mass was 2000, 5000 and 100000, respectively) and polyethylene film (relative molecular mass was greater than 400000) served as the sole carbon source successively, the strain could grow in the based liquid medium then cul-tured in 28℃, 180 rpm. Every 24 h, we measured thethalli growth concentration, reducing sugar and pH value in spectrophotome-try. After 14 days ,we measured the activity of laccase and manganese peroxidase in ABTS assay and methoxyphenol method. 60 days later, we weighed the polyethylene's remaining, observed the apparent film by using the scanning electron microscopy and measured the changes about the film of mechanical properties. The results showed that it was identified asAmycolatopsis orientalis. The growth concentration got smaller when the relative molecular mass of polyethylene got bigger. Extracellular protein content was (27.625±0.400)~(0.958±0.180)μg·mL-1. The reducing sugar was loaded with (15.664±1.764)~(2.660±0.000)μg·mL-1. And the pH value was decreased dramatically. The enzyme activity of laccase and manganese peroxidase was 3500~3000 U·L-1 and 2600~2000 U·L-1. The weight loss rate of polyethylene was (35.81%±0.39%)~(5.57%±0.22%). We observed that a large number of pores and large area of cell adhered to the surface of the PE film via SEM. Mechanical properties of the film was decreased dramati-cally, the surface energy was decreased, the contact angle of the film became smaller. It was proved thatAmycolatopsis orientalis could degrade polyethylene directly and efficiently. Our study speculates this stain can secrete exoenzyme, and oxidate the polyeth-ylene long hydrocarbon chains. At the same time, it can increase the surface energy of polyethylene. At the end, long hydrocarbon chains will transform into small molecular. We predicted that laccase and manganese peroxidase play an important role in degrading the polyethylene.关键词
聚乙烯塑料/东方拟无枝酸菌/生物降解/漆酶/锰过氧化物酶Key words
polyethylene plastics/Amycolatopsis orientalis/biodegradation/laccase/manganese peroxidase分类
资源环境引用本文复制引用
钟越,李雨竹,张榕麟,罗贝旭,张尔亮,陶宗娅,竹文坤..一株聚乙烯降解菌的筛选及其降解特性研究[J].生态环境学报,2017,26(4):681-686,6.基金项目
国家级大学生创新创业训练计划项目(201610636017) （201610636017）
四川省生物质改性材料工程技术研究中心课题(11ZXBK03) （11ZXBK03）
