Silvia Lampis

PFASs are a group of pollutants ubiquitous in the environment, for which their effects on the microbial community composition and activity of anaerobic granular sludge are still poorly understood. With our study, we aimed to provide insight into the impact of four PFASs on the methane yield of anaerobic granular sludge (AGS) using acetate as the substrate. Anaerobic granular sludge was exposed to different concentrations of 1H,1H,2H,2H-Tridecafluorooctan-1-ol (6:2FTOH), 1H,1H,2H,2H-Perfluoro-1-decanol (8:2FTOH), Tridecafluorohexane-1-sulfonic acid (PFHxS) and Perfluorooctanoic acid (PFOA). While the two fluorotelomers caused marginal changes in methane production, PFHxS and PFOA greatly inhibited acetoclastic methanogenesis. Depending on the concentration, the AGS could recover its activity after a certain number of hours when incubated with PFASs. The 50% Inhibitory Concentration (IC ₅₀ ) of the methane production was estimated to be 278.98 (± 3.2) mg/L for PFOA and 1,091.9 (± 26.78) mg/L for PFHxS. PFASs exposure also influenced the archaeal and eubacterial communities. The most significant change was observed with the eubacterial community, which showed an increase in the relative abundance of the genus Sulfurospirillum in the samples treated with 2,000 mg/L of 8:2FTOH and 600 mg/L of PFOA, whose presence grew to represent 16.65% and 45.4% of all reads in those samples. These findings provide insight into the differential impact of PFASs on methanogenic processes and highlight their potential to disrupt key microbial functions in anaerobic systems.

High-density polyethylene (HDPE) significantly contributes to persistent environmental degradation due to its non-biodegradability and widespread usage. Bioremediation of plastic-contaminated sites by ubiquitous microbial agents appears to be an effective and safe alternative method for plastic waste disposal. This study investigated HDPE degradation by Brevibacillus parabrevis EVB 2 and Bacillus velezensis EVB8, isolated from cow fecal samples. The biodegradation test was assessed through colony-forming unit (CFU) counting, pH variation, residual weight loss (%), CO₂ emission measurements at 10-day intervals, and structural analysis using scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), and Gas chromatography–mass spectrometry (GC–MS). EVB2 and EVB8 decreased the weight of HDPE films by 3.78 ± 0.90% and 1.84 ± 0.75%, respectively. Statistical analysis indicated that both reductions were significant compared to the control (p ≤ 0.05), with EVB2 showing the greatest weight loss and producing the highest CO₂ emission (104.42 ± 9.50 mg). SEM analysis indicated surface alterations in the treated films, including cracks and erosion, further validating the degradation by chemical changes and crystallinity levels detected through FTIR, XRD, and GC–MS analysis. This study demonstrates that the tested bacterial strains can achieve measurable HDPE biodegradation within 40 days without prior abiotic treatment, offering an efficient approach compared to previous studies that required pre-treatment or extended incubation periods. This work highlights the capacity of these strains to serve as effective microbial agents for HDPE biodegradation, supporting their application in the long term for sustainable plastic waste management.

Microorganisms, microbiomes, and their products (e.g., enzymes, metabolites, antibiotics, etc.) are key players in the functioning of both natural and anthropized Earth ecosystems; they can be exploited for both research purposes and biotechnological applications, including fighting the big challenges of our era, such as climate change. Culture collections (CCs) and microbial Biological Resource Centres (mBRCs) are repositories of microorganisms that investigate and safeguard biodiversity and facilitate the scientific and industrial communities’ access to microbial strains and related know-how by providing external users with skills and services. Considering this, CCs and mBRCs are pivotal institutions for the valorisation of microorganisms, the safeguarding of life, and the fostering of excellent bioscience. The aim of this review is to present the state-of-the-art of Italian CCs and mBRCs, highlighting strengths, weaknesses, threats, and opportunities. Italy is, indeed, a hotspot of microbial biodiversity with a high rate of endemism and incredible potential, not only for the food and beverage sector (i.e., “Made in Italy” products), where microorganisms can have a beneficial or a spoiling function, but also to guarantee environmental sustainability and foster the bioeconomy through the design of new bioprocesses and products. However, weaknesses, such as the lack of management rules in accordance with international quality standards, are also analysed and ways of overcoming them are discussed. In this context, an overview is given of the Joint Research Unit MIRRI-IT and the European-funded SUS-MIRRI.IT project, which aims to improve the management and sustainability of Italian microbial collections, and serves as a starting point for an innovative revolution in the context of CCs and mBRCs worldwide.

The microbial communities of the rhizospheres of vineyards have been subject to a considerable body of research, but it is still unclear how the applied soil cultivation methods are able to change the structure, composition, and level of diversity of their communities. Rhizosphere samples were collected from three neighbouring vineyards with the same time of planting and planting material (rootstock: Teleki 5C; Vitis vinifera: Müller Thurgau). Our objective was to examine the diversity occurring in bacterial community structures in vineyards that differ only in the methods of tillage procedure applied, namely intensive (INT), extensive (EXT), and abandoned (AB). For that we took samples from two depths (10–30 cm (shallow = S) and 30–50 cm (deep = D) of the grape rhizosphere in each vineyard and the laboratory and immediately prepared the slices of the roots for DNA-based analysis of the bacterial communities. Bacterial community structure was assessed by means of PCR-DGGE analysis carried out on the v3 region of 16S rRNA gene. Based on the band composition of the DGGE profiles thus obtained, the diversity of the microbial communities was evaluated and determined by the Shannon–Weaver index (H′). Between the AB and EXT vineyards at the S depth, the similarity of the community structure was 55%; however, the similarity of the D samples was more than 80%, while the difference between the INT samples and the other two was also higher than 80%. Based on our results, we can conclude that intensive cultivation strongly affects the structure and diversity of the bacterial community.

Accurate identification and typing of microbes are crucial steps in gaining an awareness of the biological heterogeneity and reliability of microbial material within any proprietary or public collection.Paenibacillus polymyxais a bacterial species of great agricultural and industrial importance due to its plant growth-promoting activities and production of several relevant secondary metabolites. In recent years, matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) has been widely used as an alternative rapid tool for identifying, typing, and differentiating closely related strains. In this study, we investigated the diversity of threeP. polymyxastrains. The mass spectra of ATCC 842^T, DSM 292, and DSM 365 were obtained, analysed, and compared to select discriminant peaks using ClinProTools software and generate classification models. MALDI-TOF MS analysis showed inconsistent results in identifying DSM 292 and DSM 365 as belonging toP. polimixaspecies, and comparative analysis of mass spectra revealed the presence of highly discriminatory biomarkers among the three strains. 16S rRNA sequencing and Average Nucleotide Identity (ANI) confirmed the discrepancies found in the proteomic analysis. The case study presented here suggests the enormous potential of the proteomic-based approach, combined with statistical tools, to predict and explore differences between closely related strains in large microbial datasets.

Lignocellulose biomasses (LCB), including spent mushroom substrate (SMS), pose environmental challenges if not properly managed. At the same time, these renewable resources hold immense potential for biofuel and chemicals production. With the mushroom market growth expected to amplify SMS quantities, repurposing or disposal strategies are critical. This study explores the use of SMS for cultivating microbial communities to produce carbohydrate-active enzymes (CAZymes). Addressing a research gap in using anaerobic digesters for enriching microbiomes feeding on SMS, this study investigates microbial diversity and secreted CAZymes under varied temperatures (37 °C, 50 °C, and 70 °C) and substrates (SMS as well as pure carboxymethylcellulose, and xylan). Enriched microbiomes demonstrated temperature-dependent preferences for cellulose, hemicellulose, and lignin degradation, supported by thermal and elemental analyses. Enzyme assays confirmed lignocellulolytic enzyme secretion correlating with substrate degradation trends. Notably, thermogravimetric analysis (TGA), coupled with differential scanning calorimetry (TGA-DSC), emerged as a rapid approach for saccharification potential determination of LCB. Microbiomes isolated at mesophilic temperature secreted thermophilic hemicellulases exhibiting robust stability and superior enzymatic activity compared to commercial enzymes, aligning with biorefinery conditions. PCR-DGGE and metagenomic analyses showcased dynamic shifts in microbiome composition and functional potential based on environmental conditions, impacting CAZyme abundance and diversity. The meta-functional analysis emphasised the role of CAZymes in biomass transformation, indicating microbial strategies for lignocellulose degradation. Temperature and substrate specificity influenced the degradative potential, highlighting the complexity of environmental–microbial interactions. This study demonstrates a temperature-driven microbial selection for lignocellulose degradation, unveiling thermophilic xylanases with industrial promise. Insights gained contribute to optimizing enzyme production and formulating efficient biomass conversion strategies. Understanding microbial consortia responses to temperature and substrate variations elucidates bioconversion dynamics, emphasizing tailored strategies for harnessing their biotechnological potential.

At appropriate concentrations, selenium (Se) is beneficial for humans. Tomato appears to be one of the best commodities for producing Se-biofortified fruit for dietary supplementation. To assess the efficacy of different enrichment protocols, a total of four on-plant and off-plant trials were conducted. Hydroponically grown tomato plants were sprayed with: (i) chemically synthesized Se nanoparticles (SeNPs) at 0, 1, and 1.5 mg Se L⁻¹ at blooming; (ii) sodium selenate (Na₂SeO₄) or SeNPs solution at 0, 5, and 10 mg Se L⁻¹ when the fruit entered the immature green stage. With regard to the off-plant trials, harvested mature green fruit were immersed in Na₂SeO₄ solution: (iii) at 0, 5, 10, and 20 mg Se L⁻¹ for 15 s under a vacuum; (iv) at 0, 40, and 80 mg Se L⁻¹ for 1 h. Spraying Na₂SeO₄ induced higher Se accumulation in plant tissue than SeNPs: both protocols were effective in enriching tomatoes. Postharvest Se enrichment via vacuum infiltration caused textural damage, whereas passive immersion in solution induced fruit Se accumulation without causing any damage. SeNPs appear to be quantitatively less effective than Na₂SeO₄, but might be environmentally safer. Elemental Se carried by NPs may be more easily incorporated into organic forms, which are more bioavailable for humans. Passive immersion may represent an alternative Se-enrichment strategy, allowing for the biofortification of harvested tomato fruit directly, with lower risks of environmental pollution.