Poly(butylene adipate-co-terephthalate) (PBAT) is a promising polymer with excellent mechanical properties and biodegradability. However, knowledge gaps between its degradation and mineralization processes in soil hampers its environmental impact and application potential. In this study, we elucidated the degradation process of PBAT, starting with the degradation of high-molecular-weight polymers into 30 intermediates, before ultimately mineralized into CO2. Bacteria and fungi drove the degradation and mineralization of these intermediates. We discovered that PBAT was synergistically degraded by combinations of 27 bacterial and fungal biomarkers rather than by single biomarkers dominated by Bacteroidota, Acidobacteriota, and Ascomycota. These combinations of related functional genes perform various functions at every stage of PBAT degradation, including breaking down molecular structures, degrading intermediates, and mineralization. Bacterial biomarkers showed greater diversity than fungal biomarkers in degrading PBAT. Our findings provide useful insights into the degradation of PBAT in soil and a foundation for systematically evaluating and controlling the environmental behavior and safety of PBAT in soil.

Context Invasive plants are one of the most significant threats to woodlands globally. Methods of invasive plant control include manual removal and herbicide application. While the impacts of control methods on invasive and off-target native plant species are often explored, the impacts on below-ground organisms, such as fungi, are less well understood.Aims We conducted a glasshouse trial to investigate the responses of soil fungal communities to herbicides and manual removal that are used to control common invasive plant species in Banksia woodland in south-western Australia.Methods Broad spectrum (glyphosate and pelargonic acid) and grass-specific (fluazifop-p-butyl) herbicides were separately applied to pots containing either Ehrharta calycina, a key invasive grass species or Eucalyptus todtiana, a native woodland tree at the recommended woodland rate. After six weeks, samples of treated soils were subjected to high throughput sequencing to determine fungal community diversity, richness, relative abundance, composition and putative ecosystem function.Key results Pelargonic acid induced the widest range of changes including decreased fungal richness and Shannon diversity but all herbicides affected community composition. Within functional groups, fluazifop-p-butyl led to a significant decrease of symbiotrophs in the mycorrhizal species.Conclusions We show that invasive species management, in the manner applied, can lead to immediate changes in fungal community composition.Implications Observed patterns require further exploration, particularly repeat testing under different environmental conditions, to better determine the impact and mode of action of herbicides on below-ground organisms. The functional changes in the soil fungal community could further disturb the soil fungal community and complicate subsequent management considerations.

Purpose Manganese (Mn) is crucial in low concentrations but can become toxic in soils and sediments, affecting plants and animals. Understanding how plants inoculated with arbuscular mycorrhizal fungi (AMF) tolerate Mn is crucial for the application of these microorganisms in the remediation of contaminated soils. Despite recognized benefits in various plant species, assessing plant-AMF interaction effectiveness in mitigating Mn toxicity is crucial for undocumented plants. Methods Acacia mangium Willd. plants were inoculated with an AMF native to a Mn mining area and grown in soil with increasing Mn levels (0, 200, and 400 mg kg(-1)) to evaluate the effects of inoculation on plant growth and plant-AMF association strategies to reduce Mn toxicity. Results Inoculation with AMF resulted in beneficial effects, minimizing Mn toxicity and enhancing plant growth, despite reduced mycorrhizal colonization and AMF spore levels in the soil. Non-inoculated plants exposed to 400 mg kg(-1) of Mn exhibited significant reductions in shoot dry mass (64.9%), number of leaves (25%), and root length (24%) compared to AMF-inoculated plants. Mn concentration was higher in the roots of AMF-inoculated plants at all Mn levels, indicating a restriction in Mn transport to the shoot, thus minimizing damage and promoting plant growth. Energy-dispersive spectroscopy identified Mn, potassium, phosphorus, iron and calcium in AMF spores, suggesting their protective role against Mn phytotoxicity and adaptability of this species of microorganism under stress conditions. Conclusion The native AMF inoculation reduces toxicity and improves the growth of A. mangium Willd. under high levels of Mn in the soil.

The ectomycorrhizal fungi Tuber melanosporum Vittad. and Tuber aestivum Vittad. produce highly valuable truffles, but little is known about the soil fungal communities associated with these truffle species in places where they co-occur. Here, we compared soil fungal communities present in wild and planted truffle sites, in which T. melanosporum and T. aestivum coexist, in Mediterranean and temperate regions over three sampling seasons spanning from 2018 to 2019. We showed that soil fungal community composition and ectomycorrhizal species composition are driven by habitat type rather than climate regions. Also, we observed the influence of soil pH, organic matter content and C:N ratio structuring total and ectomycorrhizal fungal assemblages. Soil fungal communities in wild sites revealed more compositional variability than those of plantations. Greater soil fungal diversity was found in temperate compared to Mediterranean sites when considering all fungal guilds. Ectomycorrhizal diversity was significantly higher in wild sites compared to plantations. Greater mould abundance at wild sites than those on plantation was observed while tree species and seasonal effects were not significant predictors in fungal community structure. Our results suggested a strong influence of both ecosystem age and management on the fungal taxa composition in truffle habitats.

Context. The South American grass Nassella trichotoma (serrated tussock) is widely distributed in central Argentina and one of the most damaging invasive species in Australia, New Zealand, and South Africa. In Australia, it is a weed of national significance. Aims. Our aim was to characterise the fungi able to colonise N. trichotoma seeds buried at a site in south-western Buenos Aires province, Argentina, and measure their impact on seed survival and germination. Methods. We tested the germination of healthy seeds at the beginning of the experiment (control). We buried 10 mesh bags containing 100 disinfected N. trichotoma seeds each, during 3 months in spring and autumn. At the end of each experiment, the contents of five of the bags were counted and classified as germinated, healthy, damaged, or disintegrated. Germination tests were then conducted with seeds of the latter three categories. The remaining seeds were used for recording fungal signs/symptoms, and the isolation of fungi. Key results. We identified and described a diverse group of fungi associated with the seeds and a seasonal variation in the specific composition. Seeds showing fungal signs and/or symptoms germinated less than the control. Conclusions. This is the first study on fungi associated with seeds of this species in the native range, which can affect their survival and longevity. Implications It is expected that studies on the seed microbiome may help us understand the differences in behaviour of the plant between ranges, and test the enemy-release hypothesis.