【摘要】 聚乙烯(polyethylene, PE)制品是当前使用最为广泛的通用塑料，由此造成的“白色污染”成为了世界性难题.以PE为唯一碳源的无机盐培养基，从长期覆盖塑料薄膜的土壤中富集、筛选，获得1株PE降解菌，命名为SW2.其菌落呈圆形、边缘整齐、表面湿润、光滑，革兰氏染色阴性，球状或球杆状；16S rRNA基因序列分析发现其与不动杆菌属菌株SY23一致性达99%;接触酶阳性，氧化酶与还原硝酸盐阴性，从而初步鉴定SW2为不动杆菌(Acinetobacter sp.).在含2%PE的无机盐培养基中，SW2在24 h可见明显生长，72 h其生长速率达到峰值，而在不含PE的无机盐培养基中未见生长.将SW2接种到含PE制品(农用地膜和保鲜膜)的无机盐培养基中，培养第30 d,光镜下可观察到农用地膜、保鲜膜出现明显破损，而未接种菌的对照组膜表面完好无损.结果表明：SW2可有效利用PE,并能降解PE制品.在不同温度、 pH及PE浓度条件下检测SW2的生物生长量，发现其最适生长条件为30℃, pH值为7.0, 20%PE.研究丰富了PE降解菌的菌种资源，为生物降解PE制品的进一步研究奠定了基础.更多还原

【Abstract】 Polyethylene(PE) products are the most widely used general plastics, and the resulting “white pollution” has become a worldwide problem. In this study, a PE-degrading bacterium was isolated by enriching and screening the inorganic salt medium with PE as the sole carbon source from the soil covered with plastic film for a long time and named as SW2. The colony was round, with neat edge, moist and smooth surface. The bacterium is Gram stain negative, spherical or rod-shapedv The 16S rRNA gene sequence analysis showed that it had 99% identity with Acinetobacter strain SY23, It was positive for contact enzymes, negative for oxidase and reducing nitrate. Based on the above characteristics, SW2 was preliminarily identified as Acinetobacter sp. In the inorganic salt medium containing 2% PE, SW2 had obvious growth at 24 h of culture, and reached to the peak growing at 72 h, but did not grow in the inorganic salt medium without PE. SW2 was inoculated to the inorganic salt medium containing PE products(agricultural plastic film and fresh-keeping film). On the 30th day of culture, obvious damage of agricultural plastic film and fresh-keeping film was observed under light microscope, while the surface of the control group was intact. The results show that SW2 can effectively utilize PE and degrade PE products. Under different temperature, pH and PE concentration conditions, the biological mass of SW2 was detected. The results showed that the optimal growth conditions of SW2 are 30 ℃, pH 7.0, and 20% PE. This research enriched the strain resources of PE-degrading bacteria and laid a foundation for the further study of biodegradable PE products.更多还原