Unveiling Microbial Contaminants in Agaricus bisporus Mushroom Spawns using Metagenomics Approach

Mushroom production is a practical circular economy model, leveraging agricultural by-products like wheat straw and chicken manure to yield nutrient-dense, protein-enriched foods. The edible mushroom is Agaricus bisporus, commonly known as the button mushroom. Throughout the production process of A. bisporus, a variety of bacteria and fungi are involved. The presence of bacterial and fungal contamination in mushroom spawn can lead to substantial economic losses and the development of harmful diseases in the mushrooms. Recent advancements in metagenomics have played a crucial role in identifying the main bacteria and fungi present in mushroom spawn. In this study, the contamination of mushroom spawn was analyzed using 16S rRNA and internal transcribed spacer sequencing. The data was classified into operational taxonomic units.  The most frequent bacterial contamination was caused by Bacillus, while Penicillium was the most common fungal contaminant. Gaining a comprehensive understanding of the biocontrol of mushroom pathogens has the potential to enhance mushroom yield and quality. This study, utilizing metabarcoding techniques, reveals the fungal and bacterial community present in mushroom spawn during cropping. It also highlights the importance of effective sterilization procedures to eliminate contaminants from cereal grains used for spawn production.