Analysis and comparison of fungal communities in wheat Qus and Lin-fan yeast starters used as traditional starter cultures of Shaoxing Huangjiu

The wheat Qu and Lin-fan yeast starter are two vital components of Huangjiu brewing, the microbiome composition of which can have a major impact on the end product's quality. This investigation aimed to investigate and compare the fungal diversity of eight starters, including four wheat Qus and four Lin-fan yeast starters collected from different manufacturers of Shaoxing Huangjiu using high-throughput sequencing (HTS) technology. Significant variation was observed in the fungal community composition among different starter samples. Fusarium, Epicoccum, Aspergillus and Alternaria were the most predominant fungal genera in wheat Qus. In contrast, Lin-fan yeast starters possessed relatively simple fungal communities and were predominated by Saccharomyces and Saccharomycopsis. LEfSe analysis showed that nine genus-level fungal taxa could be retrieved to differentiate the two starter types. Furthermore, the complicated association among the dominant fungi in traditional starters was revealed by utilising Spearman's correlation-based network analysis. A total of 42 positive and 28 negative correlations were identified respectively. Ultimately, this investigation described the fungal communities in wheat Qus and Lin-fan yeast starters and will aid in screening fermentation strains, which can remarkably enhance the quality of Shaoxing Huangjiu.