Overview of four Agaricus subrufescens strains used in the last 15 years in Brazil and other countries and current potential materials for the future

Decoding the chromosome-scale genome of the nutrient-rich Agaricus subrufescens: a resource for fungal biology and biotechnology

Agaricus subrufescens, also known as the "sun mushroom," has significant nutritional and medicinal value. However, its short shelf life due to the browning process results in post-harvest losses unless it's quickly dehydrated. This restricts its availability to consumers in the form of capsules. A genome sequence of A. subrufescens may lead to new cultivation alternatives or the application of gene editing strategies to delay the browning process. We assembled a chromosome-scale genome using a hybrid approach combining Illumina and Nanopore sequencing. The genome was assembled into 13 chromosomes and 31 unplaced scaffolds, totaling 44.5 Mb with 96.5% completeness and 47.24% GC content. 14,332 protein-coding genes were identified, with 64.6% of the genome covered by genes and 23.41% transposable elements. The mitogenome was circularized and encoded fourteen typical mitochondrial genes. Four polyphenol oxidase (PPO) genes and the Mating-type locus were identified. Phylogenomic analysis supports the placement of A. subrufescens in the Agaricomycetes clade. This is the first available genome sequence of a strain of the "sun mushroom." Results are available through a Genome Browser (https://plantgenomics.ncc.unesp.br/gen.php?id=Asub) and can support further fungal biological and genomic studies.

Biochemical Approaches on Commercial Strains of Agaricus subrufescens Growing under Two Environmental Cultivation Conditions

In the present work, the effect of the cultivation process, in the field and under a controlled environment, on biochemical parameters by using commercial strains of A. subrufescens were evaluated. The results obtained revealed that the strains cultivated in the field presented higher levels for most of the parameters evaluated (organic acids (20.5–48.0 g/100 g dw), tocopherols (107.0–198.6 µg/100 g dw), and phenolic acids and related compounds (245.2–359.0 µg/100 g dw and 10.6–23.7 µg/100 g dw, respectively)), except for the carbohydrates (53.4–72.6 g/100 g dw), energetic value (373–380 Kcal/100 g dw), and total free sugars (28.8–43.1 g/100 g dw), parameters in which the strains grown in a controlled environment present better results. For both cultivation systems, similar results were obtained regarding saturated, monounsaturated, and polyunsaturated fatty acids, as well as antioxidant and antimicrobial activities. These data contribute to the knowledge and highlight the characterized strains and the cultivation process, which can be used to obtain ingredients with potential applicability as a source of functional compounds.

Impact of Cultivation Substrate and Microbial Community on Improving Mushroom Productivity: A Review

Simple Summary

Lignocellulosic material and substrate formulations affect mushroom productivity. The microbial community in cultivation substrates affects the quality of the substrates and the efficiency of mushroom production. The elucidation of the key microbes and their biochemical function can serve as a useful guide in the development of a more effective system for mushroom cultivation.

Abstract

Lignocellulosic materials commonly serve as base substrates for mushroom production. Cellulose, hemicellulose, and lignin are the major components of lignocellulose materials. The composition of these components depends upon the plant species. Currently, composted and non-composted lignocellulosic materials are used as substrates in mushroom cultivation depending on the mushroom species. Different substrate compositions can directly affect the quality and quantity of mushroom production yields. Consequently, the microbial dynamics and communities of the composting substrates can significantly affect mushroom production. Therefore, changes in both substrate composition and microbial diversity during the cultivation process can impact the production of high-quality substrates and result in a high degree of biological efficiency. A brief review of the current findings on substrate composition and microbial diversity for mushroom cultivation is provided in this paper. We also summarize the advantages and disadvantages of various methods of mushroom cultivation by analyzing the microbial diversity of the composting substrates during mushroom cultivation. The resulting information will serve as a useful guide for future researchers in their attempts to increase mushroom productivity through the selection of suitable substrate compositions and their relation to the microbial community.

Influence of strains and environmental cultivation conditions on the bioconversion of ergosterol and vitamin D2 in the sun mushroom

BACKGROUND

The fungus Agaricus subrufescens is grown commercially in China, the USA, Brazil, Taiwan and Japan, among others. However, each country adopts a cultivation system that significantly influences the agronomical parameters and chemical composition of the harvested mushrooms. In this study, the influence of the cultivation process on the content of ergosterol and vitamin D₂ was evaluated.

RESULTS

Four commercial strains of A. subrufescens (ABL 04/49, ABL CS7, ABL 18/01 and ABL 19/01) and two environmental cultivation conditions (in the field and a controlled chamber with the absence of sunlight) were used. Infield cultivation, ABL CS7 and ABL 19/01 strains presented better agronomic parameters, whereas in a protected environment ABL 19/01, ABL 04/49 and ABL 18/01 demonstrated better performance, respectively. The highest biological efficiency value (64%) was provided by ABL 19/01 strain in a controlled environment.

CONCLUSION

The highest content in ergosterol (990 mg kg^-1 ) and vitamin D₂ (36.8 mg kg^-1 ) were observed in mushrooms obtained in the field from strain ABL 04/49, which presents reasonable agronomic parameters for cultivation. © 2021 Society of Chemical Industry.

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.