The exposure of microorganisms to conventional plastics is a relatively recent occurrence, affording limited time for evolutionary adaptation. As part of the EU-funded project BioICEP, this study delves into the plastic degradation potential of microorganisms isolated from sites with prolonged plastic pollution, such as plastic-polluted forests, biopolymer-contaminated soil, oil-contaminated soil, municipal landfill, but also a distinctive soil sample with plastic pieces buried three decades ago. Additionally, samples from Arthropoda species were investigated. In total, 150 strains were isolated and screened for the ability to use plastic-related substrates (Impranil dispersions, polyethylene terephthalate, terephthalic acid, and bis(2-hydroxyethyl) terephthalate). Twenty isolates selected based on their ability to grow on various substrates were identified as Streptomyces, Bacillus, Enterococcus, and Pseudomonas spp. Morphological features were recorded, and the 16S rRNA sequence was employed to construct a phylogenetic tree. Subsequent assessments unveiled that 5 out of the 20 strains displayed the capability to produce polyhydroxyalkanoates, utilizing pre-treated post-consumer PET samples. With Priestia sp. DG69 and Neobacillus sp. DG40 emerging as the most successful producers (4.14% and 3.34% of PHA, respectively), these strains are poised for further utilization in upcycling purposes, laying the foundation for the development of sustainable strategies for plastic waste management.

Here, we present methods for screening any newly isolated microbial biobank for enzymes, antioxidants, and additional secondary metabolites. Bioactive compounds and enzymes produced by fungi have many applications in industry as valuable leads for pharmaceuticals, nutraceuticals, and potential strains for industrial biotechnology. In this study, fungi collected from Irish habitats were purified and identified by sequencing Internal Transcribed Spacer (ITS) ribosomal DNA regions. Reducing sugars released because of enzyme hydrolysis was used to estimate the relative enzyme activity for carboxymethyl cellulase, pectinase, β-xylanase, arabinoxylanase, mannanase, and galacto-mannanase in the fungal extracts and was normalized against the crude protein content to express relative enzyme activity/milligram. The best enzyme producers were as follows: F1 Clonostachys rosea demonstrated 351.63 U/mg β-xylanase and 645.50 U/mg arabinoxylanase activity; F2 Penicillium expansum had 25 U/mg cellulase and 112.5 U/mg pectinase activity; F3 Fusarium avenaceum had 139.36 U/mg arabinoxylanase, 52.33 U/mg galacto-mannanase, and 45 U/mg mannanase activity; and F9 Trichoderma koningii had 372.15 U/mg β-xylanase and 655.18 U/mg arabinoxylanase activity. In addition to enzyme activity, these strains also exhibited antioxidant activity when tested in Oxygen radical absorbance capacity (ORAC), 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric ion reducing antioxidant power (FRAP) assays, with activity expressed as μmol Trolox equivalents (TE) per gram of dried fungal extract. In results from the ORAC assay, F1 C. rosea reported 655,669 µmol TE/g; F2 P. expansum had 636,889 µmol TE/g; and F3 F. avenaceum had 4,488,035 µmol TE/g. High DPPH activity was observed for F1 C. rosea at 12,572 µmol TE/g, F3 F. avenaceum at 22,646 µmol TE/g, and F9 T. koningii at 22,558 µmol TE/g. F1 C. rosea, F3: F. avenaceum, and F9 T. koningii also reported high FRAP activity at 36,019 µmol TE/g, 69,325 µmol TE/g, and 25,812 µmol TE/g, respectively. In terms of secondary metabolites, the main compounds detected for the isolates were F1 C. rosea produced benzoic acid, 3-pyridinepropionic acid, and cyclo(-Gly-Phe); F2 P. expansum produced Cyclo(-Gly-Phe) and prenitremone A; F3 F. avenaceum produced cyclo(-Leu-Leu) and p-anisaldehyde; and F9 T. koningii produced cyclo(-Gly-Phe), canescin, citreoviridin X, and cyclopaldic acid. These selected isolates indicate that Irish fungi are a potential source of enzymes and novel biologically active compounds useful in industrial biotechnology and bioproduction supporting sustainability and responsible environmental management.

Bovine omentum, a by-product of beef processing, offers potential for collagen recovery within the circular bioeconomy. It consists mainly of lipids (42.14%) and proteins (18.79%), such as collagen. In this study, collagen was isolated using acid-based and enzymatic methods. Acid-soluble collagen (ASC) was successfully extracted, yielding 3.98%. Additionally, enzymatic extraction of collagen from the residue obtained after ASC extraction using Protana^® Prime (1–10%, w/w) resulted in variable yields (4.98% to 11.15%) (p < 0.05). The maximum solubility of all collagen samples was observed at pH 3, while NaCl concentrations above 4% (w/v) significantly reduced solubility (p < 0.05). ASC demonstrated the highest emulsifying activity index and emulsion stability index (213.73 m²/g and 172.09 min, respectively) (p < 0.05), whereas enzyme-extracted collagens exhibited comparatively lower emulsifying capacities, particularly at higher enzyme concentrations (7.5% and 10%). FTIR spectra revealed characteristic bands for collagen, indicating that the triple helical structure was maintained, irrespective of treatment. All collagen samples contained glycine as the major amino acid (approximately 1/3rd of the total amino acid) with proline and hydroxyproline. SDS-PAGE identified type I collagen, which consisted of αI and αII chains. Therefore, bovine omentum would be an alternative source of collagen for various applications in the food industry.