The Succession of Bacterial Community Attached on Biodegradable Plastic Mulches During the Degradation in Soil

Abstract

Despite the increasing application of biodegradable plastic mulches (BDMs) in agriculture, the colonization and succession of the attached microbial community on BDMs during their degradation processes remain poorly characterized. Here, we buried four types of commonly used BDMs, including pure polylactic acid (PLA), pure polybutylene adipate terephthalate (PBAT), and two mixtures of PLA and PBAT (85:15 and 15:85 w/w), and one classic polyethylene (PE) mulch in soil for 5 months. Both plastic components and incubation time significantly shaped the β-diversities of microbiota on the plastic mulches (p < 0.001). Meanwhile, the microbial compositions and community structures on BDMs were significantly different from PE mulch, and when excluding PE mulch, the microbiota varied more with time than by the composition of the four BDMs. The orders Burkholderiales and Pseudonocardiales were dominant on most BDMs across different time points. The genus Ramlibacter was revealed as a common biomarker for both PLA and PBAT by random-forest model, and all biomarkers for the BDMs belonged to the dominant order Burkholderiales. In addition, degradation-related and pathogen-related functional taxa were enriched in all mulches among all 40 functional groups, while surprisingly, potential pathogens were detected at higher levels on BDMs than PE. For community assembly on all mulches, the drift and dispersal processes played more important roles than selection, and in particular, the contribution of stochastic drift increased during the degradation process of BDMs while selection decreased, while the opposite trend was observed with PE mulch. Overall, our results demonstrated some degradation species and pathogens were specifically enriched on BDMs, though stochastic processes also had important impacts on the community assembly. It suggested that, similar to conventional plastic mulch, the increased usage of BDMs could lead to potential hazards to crops and human health.

Discovery of plastic-degrading microbial strains isolated from the alpine and Arctic terrestrial plastisphere

“…In our study we isolated microbial strains from the plastisphere of cold terrestrial environments belonging almost exclusively to the phyla Actinobacteria, Proteobacteria and Ascomycota. Especially the orders Burkholderiales, Pseudomonadales, and Streptomycetales and the genus Pseudogymnoascus were repeatedly isolated, which agrees with previous reports of the soil plastisphere microbiome analyzed by culture-independent genomic methods ( Rüthi et al, 2020 , 2023 ; Ju et al, 2021 ; Sun et al, 2022 ; Zhang et al, 2022 ) and microbial cultivation ( Cosgrove et al, 2007 ). Further, these phyla (+ Firmicutes) are the principal taxa known to be involved in the degradation of PUR, PBAT and PLA ( Cregut et al, 2013 ; Gambarini et al, 2021 ).…”

Deciphering the Mechanisms Shaping the Plastisphere Microbiota in Soil

“…Similarly, studies about plastisphere in soil also demonstrated the dominant roles of stochastic processes in shaping the plastisphere microbiota. For instance, Ju et al have found a higher proportion of stochastic processes than deterministic processes for plastisphere ( 45 ). In the current study, the NST values indicated that the stochastic processes dominantly contributed to the plastisphere communities.…”

Community response of soil microorganisms to combined contamination of polycyclic aromatic hydrocarbons and potentially toxic elements in a typical coking plant

“…The soil genomic DNA was extracted by the PowerSoil DNA Isolation Kit (Qiagen, Germany) following the manufacturer’s instructions. The extracted DNA was amplified by the 16S rRNA universal primer set, 515 forward (5’-GTGCCAGCMGCCGCGGTAA-3′) and 806 reverse (5-'GGACTACHVGGGTWTCTAAT-3′) that targeted the V4 hypervariable regions of the prokaryotic 16S rRNA genes ( Yarza et al, 2014 ; Ju et al, 2021 ). The ITS2 region of fungal ribosomal encoding genes was amplified with the primers gITS7 (5’-GTGARTCATCGARTCTTTG-3′) and ITS4 (5’-TCCTCCGCTTATTGATATGC-3′).…”

“…Furthermore, we constructed an RF model to identify the most distinguished taxa from inside and outside of coking plant samples and test the accuracy of the biomarkers. Significantly enriched or depleted ASVs of bacteria and fungi were designated as biomarkers and the RF package v.4.6–14 was used with default parameters ( Zhang et al, 2019 ; Ju et al, 2021 ).…”