It Works! Organic-Waste-Assisted Trichoderma spp. Solid-State Fermentation on Agricultural Digestate

Abstract

This study aimed at valorizing digestate through Trichoderma spp. solid-state fermentation (SSF) to produce a potentially ameliorated fertilizer combined with fungal biomass as a value-added bioproduct. Plant-growth-promoting Trichoderma atroviride Ta13, T. reesei RUT-C30, T. asperellum R, and T. harzianum T-22 were tested on different SSF substrates: whole digestate (WD), digestate dried up with wood sawdust (SSF1), and digestate enriched with food waste and dried up with wood sawdust (SSF2). The fungal biomass was quantified by using a qPCR assay. The growth of the four Trichoderma spp. was only observed on the SSF2 substrate. The highest quantity of mycelium was produced by T. reesei RUT-30 (689.80 ± 80.53 mg/g substrate), followed by T. atroviride Ta13, and T. asperellum R (584.24 ± 13.36 and 444.79 ± 91.02 mg/g substrate). The germination of Lepidium sativum seeds was evaluated in order to assess the phytoxicity of the Trichoderma-enriched substrate. The treatments with 7.5% SSF2-R, 3.75% SSF2-T-22, and 1.8% SSF2-Ta13 equally enhanced the root elongation in comparison to the non-fermented SSF-2. This study demonstrated that digestate, mixed with agro-food waste, was able to support the cultivation of Trichoderma spp., paving the way to the valorization of fermented digestate as a proper biofertilizer.

Solid-State Fermentation of Trichoderma spp.: A New Way to Valorize the Agricultural Digestate and Produce Value-Added Bioproducts

“…The previous results about the aptitude of digestate mixed with agro-industrial wastes to serve as a substrate for fungal growth were so confirmed and extended also to the production of enzymes and metabolites.…”

“…The mycelial mass was quantified using the standard curve method as described by Alias et al . Briefly, 5 g of homogenized fermented substrate was collected at 0, 3, 6, 13, 20, 27, and 34 days after inoculation.…”

“…Only a couple of methods for the valorization of digestate as a substrate for the solid-state fermentation (SSF) have been reported up to now: as a biopesticide, with the inoculum of Bacillus thuringiensis (Bt) or for Trichoderma spp. biomass production . In SSF, microorganisms grow on a solid substrate in the absence or near absence of free water and convert the substrate into a value-added product.…”

Screening of Cellulase Genes and Degrading Activities of Trichoderma Asperellum via Solid-State Fermentation of Rice Straw and Sugarcane Bagasse

“…It must be mentioned that India cultivated in 2016 approximately 43.19 million hectares of rice producing 280 million tons of wastes (Sarangi et al, 2021). Moreover, the European countries produce 180 million tons of wastes yearly via biogas production (Alias et al, 2022). Since the agricultural wastes as rice straw contain cellulose, hemicellulose and lignin, therefore this makes it difficult to degrade (Kaur et al, 2019).…”

Editorial for Special Issue “Microorganisms and Organic Waste Valorisation”

“…One contribution [ 5 ] evaluates digestate valorisation through fungal solid-state fermentation to produce an ameliorated biofertiliser as a value-added product. Brémond et al [ 6 ] evaluate the efficacy of digestate post-treatment with isolated ligninolytic aerobic consortia in increasing methane recovery during recirculation.…”