Isolation and Identification of Molds on the Surface of River Snail Rice Noodles

Abstract:

Mold contamination can adversely affect the quality of river snail rice noodles. To clarify the mold biodiversity, molds on the surface of river snail rice noodles were isolated and identified, and their growth characteristics (colony morphology, spore germination, and mycelial growth) were analyzed. Comparison of ITS-rDNA sequences and NCBI sequences revealed the isolation of 32 mold species under 11 mold genera, with five dominant mold species identified, namely Penicillium sp. (6.3%), Cladosporium sp. (40.6%), Alternaria sp. (9.4%), Aspergillus sp. (9.4%), and Talaromyces sp. (9.4%). The phylogenetic tree showed that these isolates exhibited high similarity (>99%) with the known mold species. Penicillium sp. exhibited the highest spore germination and mycelial growth rates, whereas Aspergillus sp. and Cladosporium sp. exhibited low spore germination rates during the early stage despite their high mycelial growth rates. To the best of our knowledge, this is the first report on the isolation and identification of molds on the surface of river snail rice noodles, revealing a variety of mold species on the surface of rice noodles that indicate potential risks in food quality and safety. The findings of this study can facilitate the development of intervention technology for eliminating mold contamination in river snail rice noodles.