Assessment of seasonal feedstock changes in long-term anaerobic digestion: Monoterpenes influence on the microbial consortium Trujillo-Reyes, Ángeles García Pérez, Ana Serrano Moral, Antonio Ramiro García, Javier Cubero-Cardoso, Juan Fermoso, Fernando G. Antimicrobial properties Biodegradation Inhibition Metabolites Toxicity test Volatile organic compounds This work was funded by the project entitled “Employing circular economy approach for OFMSW management within the Mediterranean countries – CEOMED” number A_B.4.2_0058, funded under the ENI CBC MED 2014–2020 programme. The authors are also very grateful to the Spanish Ministry of Science and Innovation for funding this research through the project TED2021-129599B. Dr. Antonio Serrano is grateful to the Economic Transformation, Industry, Knowledge, and Universities Department of the Andalucia Autonomous Government for his Emergia fellowship (EMERGIA20_00114). Juan Cubero-Cardoso received funding from the JDC2022-050255-I grant, which is financed by MCIU/AEI/10.13039/501100011033 and the European Union's "NextGenerationEU"/PRTR program. Monoterpenes are antimicrobial compounds widely distributed in vegetable biomass, whose inhibitory potential for anaerobic digestion is underestimated. In this research, the toxic effect of limonene and fenchone, two of the main monoterpenes present in vegetable biomasses, and those of 4-terpineol, α-terpineol, and p-cymene, compounds described as main metabolites of limonene degradation, have been assessed. Methane production was totally inhibited at dosed of 1000 mg L-1 of fenchone and limonene and at 600 mg L-1 of p-cymene and 4-terpineol. Based on the methane production rate, the inhibition followed the next trend: α-terpineol << fenchone < limonene ≈ p-cymene < 4-terpineol. Regardless of dosed concentration, monoterpenes were mostly degraded at the end of the experiment (>85%), except p-cymene at 600 mg L-1. Therefore, monoterpenes could entail a high risk of inhibition that can be aggravated by the difficulty to accurately follow their concentration and by the scarce information on their effect on anaerobic process. 2025-12-10T07:58:52Z 2025-12-10T07:58:52Z 2025 journal article Published version: A. Trujillo-Reyes et al. Biomass and Bioenergy 194 (2025) 107674. https://doi.org/10.1016/j.biombioe.2025.107674 https://hdl.handle.net/10481/108676 10.1016/j.biombioe.2025.107674 eng open access Elsevier