Biodegradation of mixture of plastic films by tailored marine consortia.
Biodegradation of mixture of plastic films by tailored marine consortia.
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DOI：
10.1016/j.jhazmat.2019.04.078
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发表时间：
2019-08
影响因子：
13.6
通讯作者：
Evdokia Syranidou;Katerina Karkanorachaki;Filippo Amorotti;Apostolos Avgeropoulos;B. Kolvenbach;N. Zhou;F. Fava;P. Corvini;N. Kalogerakis
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作者：
Evdokia Syranidou;Katerina Karkanorachaki;Filippo Amorotti;Apostolos Avgeropoulos;B. Kolvenbach;N. Zhou;F. Fava;P. Corvini;N. Kalogerakis
这项工作揭示了自然风化聚合物表面的物理化学变化以及生物膜形成和降解过程导致的聚合物浮力的变化。为了支持降解假说，进行了一项微观实验，将自然风化的塑料碎片的混合物与当地的远洋生物群落一起孵化。采用一系列分析来描述聚合物的物理化学特性（FTIR、SEC 和 GPC、下沉速度）以及生物膜群落 (NGS) 的变化。在第二阶段结束时，经过微生物处理的 PE 薄膜表面双键比例增加，同时 PS 薄膜的轮廓也发生变化。 PE 碎片的分子量随着孵育时间的增加而增加，在第 5 个月时达到原始碎片的分子量 (230,000 g mol−1)，但在整个实验期间浮力没有显示出差异。 PS 片段的数均分子量下降（INDG 和 BIOG 处理分别下降 33% 和 27%），意味着断链；还测量了表面带有生物膜的 PS 薄膜的下沉速度，与最初风化的碎片相比，加速了（超过 30%）的下沉速度。红细菌目、海洋螺菌目和伯克霍尔德菌目在不同的普拉球群落中占主导地位，芽孢杆菌属和假诺卡氏菌属将这些组合与浮游生物的对应物区分开来。功能分析预测携带异生物质和碳氢化合物降解基因的粘附细胞的过度表达。考虑到这些，我们可以建议定制的海洋联盟有能力在塑料混合物的存在下蓬勃发展并参与其降解。
This work sheds light on the physicochemical changes of naturally weathered polymer surfaces along with changes of polymer buoyancy due to biofilm formation and degradation processes. To support the degradation hypothesis, a microcosm experiment was conducted where a mixture of naturally weathered plastic pieces was incubated with an indigenous pelagic community. A series of analyses were employed in order to describe the alteration of the physicochemical characteristics of the polymer (FTIR, SEC and GPC, sinking velocity) as well as the biofilm community (NGS). At the end of phase II, the fraction of double bonds in the surface of microbially treated PE films increased while changes were also observed in the profile of the PS films. The molecular weight of PE pieces increased with incubation time reaching the molecular weight of the virgin pieces (230,000 g mol−1) at month 5 but the buoyancy displayed no difference throughout the experimental period. The number-average molecular weight of PS pieces decreased (33% and 27% in INDG and BIOG treatment respectively), implying chain scission; accelerated (by more than 30%) sinking velocities compared to the initial weathered pieces were also measured for PS films with biofilm on their surface. The orders Rhodobacterales, Oceanospirillales and Burkholderiales dominated the distinct platisphere communities and the generaBacillusandPseudonocardiadiscriminate these assemblages from the planktonic counterpart. The functional analysis predicts overrepresentation of adhesive cells carrying xenobiotic and hydrocarbon degradation genes. Taking these into account, we can suggest that tailored marine consortia have the ability to thrive in the presence of mixtures of plastics and participate in their degradation.