A new circular economy approach for integrated production of tomatoes and mushrooms.

Spent mushroom Substrate is the by-product generated at the end of the mushroom growing cycle. It can be used in agriculture for different purposes, including seedling production, soil conditioning or application as an organic fertilizer. Tomato is one of the world́s most important crops, requiring considerable care, in terms of both nutrition and disease control. The objective of this study was to investigate the viability of spent mushroom substrate as a nutrient source for tomato seedlings and develop an integrated tomato and mushroom co-production system. For seedling production, different compositions were evaluated with spent mushroom substrate from Pleurotus ostreatus or substrate colonized with Agaricus bisporus. The parameters evaluated comprised germination rate, seedling quality and physicochemical analysis. A tomato and mushroom integrated production system was developed using a 40-liter pot divided into upper (spent mushroom substrate and soil), middle (spent mushroom substrate from P. ostreatus) and lower (gravel) layers. For seedlings production, plants treated with the substrate colonized with A. bisporus presented a superior root length (10.1 cm) and aerial part length (6.6 cm). Co-production of tomato and mushrooms was also shown to be viable. In this co-cultivation system between tomato and mushroom, the treatment with the substrate colonized with A. bisporus differed from others, with this treatment presenting high yields of tomato (2.35 kg/plant pot) and mushrooms (1.33 kg/plant pot) within the same bucket. With this co-production system, the tomato production time was reduced by 60 days and prolonged continuous mushroom production by 120 days. These findings show a sustainable approach to manage different agroindustrial residues, encouraging the use of these residues for olericulture and fungiculture production.

Outdoor versus indoor cultivation: Effects on the metabolite profile of Agaricus subrufescens strains analyzed by untargeted metabolomics.

Agaricus subrufescens has emerged as an important culinary-medicinal mushroom over the last decades. Efforts have been dedicated to upgrade the A. subrufescens productive process via strain selection and cultivation scaling-up. However, little is known on the influence of those variables on the metabolite profiles and nutraceutical properties of this mushroom. In this work, the effects of outdoor versus indoor cultivation on the metabolite profiles of five commercial strains of A. subrufescens were investigated by untargeted metabolomics. UHPLC-MS coupled to multivariate data analysis revealed that the concentration of several metabolites with reported health-related properties as well as related to taste and browning varied significantly between strains and were affected by the cultivation system in a strain-dependent manner. Data suggest that increasing the production scale by means of indoor cultivation may decrease the nutraceutical quality of some A. subrufescens strains while also affecting taste and browning susceptibility to different extents.