Detection and control of off-flavour compound-producing streptomycetes on locally produced nuts using streptophages

Abstract

Members of the phylum Actinomycetota are the most prominent part of the soil microbiota, more specifically the species within the genus Streptomyces of this phylum. Key functions of Streptomyces species (or streptomycetes in general terms) include nutrient cycling and plant growth promotion and disease protection. However, these species can also produce volatile organic compounds, predominantly geosmin, which is responsible for musty and mildew scents that are unpleasant to humans and can negatively impact the nut crop industry as odorous nuts generally lose their market value. Bacterial viruses, called bacteriophages have been previously used successfully in agriculture and aquaculture to remove such odorous species and they may therefore be applied to the nut industry. To eliminate these compounds, the producer streptomycetes may be selectively removed from nut surfaces using streptophages. The removal of Streptomyces species from nut surfaces can then be expected to minimise geosmin production, therefore removing the unpleasant off-flavours and benefiting the nut industry.