Solid-state Fermentation of Municipal Green Waste with Trichoderma viride : IAA Production in Tray Reactors and its Biostimulant Effect on Early Growth of Lettuce Seedlings (Lactuca sativa L.)
Solano Porras, Carlos (Universitat Autònoma de Barcelona. Departament d'Enginyeria Química, Biològica i Ambiental)
Sánchez, Antoni (Universitat Autònoma de Barcelona. Departament d'Enginyeria Química, Biològica i Ambiental)
Barrena, Raquel (Universitat Autònoma de Barcelona. Departament d'Enginyeria Química, Biològica i Ambiental)
Ballardo, Cindy (Universidad Nacional del Centro del Perú)
Artola, Adriana (Universitat Autònoma de Barcelona. Departament d'Enginyeria Química, Biològica i Ambiental)

Date:	2026
Abstract:	The world-wide expansion of urban areas has led to an increase of municipal green waste (MGW) generation. In this study, indole-3-acetic acid (IAA), a known biostimulant, was produced using Trichoderma viride through solid-state fermentation (SSF) of MGW in a tray bioreactor. The production of IAA was optimized under SSF conditions, achieving a maximum yield of 112. 6 μg IAA g⁻ dry weight at 28 °C, 65% humidity, and 1% of L-tryptophan supplementation based on total weight. The biostimulant effectiveness was further evaluated in lettuce (Lactuca sativa L. ) germination pot tests, showing significant improvements in growth parameters, photosynthetic pigments and nutrient uptake. Fermented solids with two different IAA concentrations (112. 6 and 60. 0 μg IAA g⁻ dw) were tested on lettuce plants, resulting in higher biomass, root and shoot length, and overall vigour plant compared to a control without IAA at 7, 14, 21, 28, and 35 days after planting. Additionally, chlorophyll content, carotenoids, and the absorption of key nutrients (K⁺, Ca⁺, Mg⁺, P, S) were significantly enhanced. These findings highlight the potential of Trichoderma viride as a biostimulant producer, aligning this strategy to circular economy principles by valorising MGW into agricultural useful bioproducts, thus reducing the dependency on chemical fertilizers, while promoting sustainable agriculture.
Grants:	Agencia Estatal de Investigación PLEC2022-009252
Note:	Altres ajuts: acords transformatius de la UAB
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Indole-3-acetic acid ; Trichoderma viride ; Municipal green waste ; Circular bioeconomy ; Biostimulant ; Lettuce germination
Published in:	Waste and Biomass Valorization, April 2026, ISSN 1877-265X

DOI: 10.1007/s12649-026-03607-x

13 p, 1.5 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Engineering > Composting Research Group (GICOM)
Articles > Research articles
Articles > Published articles