Fungal Diversity of Natural Fermented Soybean Curd in Rural Areas

In order to explore the diversity of fungi in rural fermented bean curd, in this study, natural fermented bean curd in rural areas of Shangrao city, Jiangxi province was taken as the object. Strain identification and fungal diversity of natural fermented bean curd were conducted by dilution plate culture method, combined with morphological characteristics and LSU sequence sequencing. The results showed that 277 strains were isolated from 24 samples of fermented bean curd from eight sampling sites in Shangrao, and 26 species from 9 genera were identified. According to the separation frequency, Penicillium (29.04%), Aspergillus (24.65%), Talaromyces (22.88%) and Fusarium (10.57%) were the dominant genus of all the isolates, and there were significant differences among the dominant genera from different sources. The results of diversity index (H) showed that the diversity index (H=1.92) around Shitang in Yanshan County was the highest and the flora richness was high, while the diversity index (H=0.74) in Hongxing living area of Dexing city was the lowest and the flora richness was low. The results of similarity index (Cj) showed that the similarity coefficient of the fungi in fermented bean curd around Shitang in Yanshan County and Xiaokang city Anli community of Guangfeng area was 1.00, and the similarity degree of the fungi in the fermented bean curd was relatively high, while the similarity degree of the fungi in Wenshan Village of Zixi Township and Zhangshu Town of Yushan County was extremely low, with the similarity coefficient of 0.29. The results would provide a theoretical basis for improving the quality and safety of fermented bean curd.