title: Mineralisation of14C-labelled polystyrene plastics by Penicillium variabile after ozonation pre-treatment.
abstract: Large amounts of polystyrene (PS), one of the most widely used plastics in the world, end up in the environment through industrial discharge and littering, becoming one of the major components of plastic debris. Such plastics, especially the small-sized microplastics and nanoplastics, have received increasing concerns in terms of their potential environmental risks. Feasible approaches for the degradation of PS in waste materials and in the environment are highly desirable. Physicochemical pretreatments of PS may be applied to enhance biological degradation. In the present study, we synthesized14C-labelled PS polymers, either uniformly labelled on the ring ([U-ring-14C]-PS) or labelled at the β-carbon position of the alkyl chain ([β-14C]-PS), and investigated the mineralisation of the14C-PS polymers by the fungus Penicillium variabile CCF3219 as well as the effect of ozonation as a physico-chemical pre-treatment on the mineralisation by the fungi. Biodegradation of the14C-PS polymers was studied in liquid medium (pH 7.5, without additional carbon substrate) with P. variabile for 16 weeks. During the incubation time,14CO2was captured to calculate the mineralisation of14C-PS and the remaining polymers were analysed by means of scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectrometry and gel-permeation chromatography (GPC). The results showed that the fungi mineralised both labelled polymers, and that the [U-ring-14C]-PS with a lower molecular weight led to a higher mineralisation rate. Ozonation pre-treatment strongly enhanced mineralisation of [β-14C]-PS. SEM analysis showed that the surface of the ozonated [β-14C]-PS became uneven and rough after the incubation, indicating an attack on the polymer by P. variabile. FT-IR analysis showed that ozonation generated carbonyl groups on the [β-14C]-PS and the amount of the carbonyl groups decreased after incubation of the [β-14C]-PS with P. variabile. GPC analysis showed that the molecular weights of the ozonated [β-14C]-PS decreased after incubation. The present data suggest that ozonation pretreatment could be a potential approach for degradation of PS waste and remediation of PS-contaminated sites.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China; School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, Muttenz CH-4132, Switzerland.
authors.forename: Lili
authors.initials: L
authors.lastname: Tian
authors.affiliation: School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, Muttenz CH-4132, Switzerland.
authors.forename: Boris
authors.initials: B
authors.lastname: Kolvenbach
authors.affiliation: School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, Muttenz CH-4132, Switzerland.
authors.forename: Nora
authors.initials: N
authors.lastname: Corvini
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China.
authors.forename: Songfeng
authors.initials: S
authors.lastname: Wang
authors.affiliation: School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, Muttenz CH-4132, Switzerland.
authors.forename: Nasrin
authors.initials: N
authors.lastname: Tavanaie
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China.
authors.forename: Lianhong
authors.initials: L
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China.
authors.forename: Yini
authors.initials: Y
authors.lastname: Ma
authors.affiliation: J. F. Blumenbach Institute of Zoology and Anthropology, University of Göttingen, Berliner Str. 28, 37073 Göttingen, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Scheu
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China; School of Life Sciences, University of Applied Sciences and Arts Northwestern Switzerland, Gründenstrasse 40, Muttenz CH-4132, Switzerland.
authors.forename: Philippe François-Xavier
authors.initials: PF
authors.lastname: Corvini
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Xianlin Avenue 163, 210023 Nanjing, China. Electronic address: ji@nju.edu.cn.
authors.forename: Rong
authors.initials: R
authors.lastname: Ji
mesh_terms: D001673:Biodegradation, Environmental; D002250:Carbon Radioisotopes; D010126:Ozone / Q000737:chemistry*; D010407:Penicillium / Q000254:growth & development*; D011137:Polystyrenes / Q000737:chemistry / Q000378:metabolism
chemical_list: D002250:Carbon Radioisotopes; D011137:Polystyrenes; D010126:Ozone
keywords: (14)C-radiotracer; Biodegradation; Microplastic; Mineralisation; Penicillium variabile; Polystyrene