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.

HS-SPME/GC-MS Assisted Analysis of Volatile Constituents in Different Strains of Shiitake Culinary- Medicinal Mushroom, Lentinus edodes (Agaricomycetes).

The shiitake culinary-medicinal mushroom Lentinus edodes is one of the most consumed species worldwide because it has nutritional, medicinal, and palatable properties. Its organoleptic characteristics contribute substantially to its high popularity. The pleasant aromas result from the presence of volatile compounds. The objective of the present work was to study the profiles of volatile constituents of fresh fruiting bodies of five strains of L. edodes. The volatile compounds were extracted by solid phase microextraction method and analyzed by gas chromatography and mass spectrometry. The aromatic profiles of the strains revealed variability. Both alcohols and sulfides were the most abundant volatile compounds. LE6 strain presented the highest number of volatile compounds with predominance of sulfides (dimethyl pentasulfide, s-tetrathiane) and for LE2, the aldehydes were the most representative chemical class with the main volatile being (E)-2-octen-1-al.

Evaluation of the infection process by Lecanicillium fungicola in Agaricus bisporus by scanning electron microscopy.

BACKGROUND: Lecanicillium fungicola causes dry bubble disease in Agaricus bisporus mushrooms leading to significant economic losses in commercial production. AIMS: To monitor the infection process of L. fungicola in Brazilian strains of A. bisporus. METHODS: The interaction between the mycelium of L. fungicola (LF.1) and three strains of A. bisporus (ABI 7, ABI 11/14 and ABI 11/21) was studied. Electron microscopy and X-ray microanalyses of vegetative growth and basidiocarp infection were evaluated. RESULTS: Micrographs show that the vegetative mycelium of the Brazilian strains of A. bisporus is not infected by the parasite. The images show that the pathogen can interlace the hyphae of A. bisporus without causing damage, which contributes to the presence of L. fungicola during the substrate colonization, allowing their presence during primordial formation of A. bisporus. In the basidiocarp, germ tubes form within 16h of infection with L. fungicola and the beginning of penetration takes place within 18h, both without the formation of specialized structures. CONCLUSIONS: Scanning electron microscopy enabled the process of colonization and reproduction to be observed within the formation of phialides, conidiophores and verticils of L. fungicola. The formation of calcium oxalate crystals by the pathogen was also visible using the X-ray microanalysis, both at the hyphae in the Petri plate and at basidiocarp infection site.

Spore behaviors reveal a category of mating-competent infertile heterokaryons in the offspring of the medicinal fungus Agaricus subrufescens.

Strain breeding is much less advanced in the edible and medicinal species Agaricus subrufescens than in Agaricus bisporus, the button mushroom. Both species have a unifactorial system of sexual incompatibility, a mating type locus tightly linked to a centromere, and basidia producing both homokaryotic (n) and heterokaryotic (n + n) spores. In A. bisporus, breeding is mainly based on direct selection among the heterokaryotic offspring and on hybridization between homokaryotic offspring. The parental heterozygosity is highly maintained in the heterokaryotic offspring due to suppression of recombination and preferential pairing in the spores of nuclei, each one per second meiotic divisions; such "non-sister nuclei" heterokaryons are fertile. In A. subrufescens, recent studies revealed that recombination is not suppressed and that nuclei from the same second meiotic division can also be paired in a spore that give rise to a "sister nuclei" heterokaryon in which the nuclei bear the same mating type allele. The objective of the present work was to investigate the potential function of the different categories of spores in A. subrufescens and their possible use in a genetic breeding program. Using eight co-dominant molecular markers, we found that half of the offspring of the A. subrufescens strain WC837 were heterokaryotic, one quarter of them being sister nuclei heterokaryons. These heterokaryons were infertile and behaved like homokaryons, being even able to cross between each other. In contrast, non-sister nuclei heterokaryons could fruit but inconsistently due to inbreeding depression. Potential roles of these two categories of heterokaryons in nature and consequences for strain breeding are discussed.