The role of apricot kernels in shaping the microbial community composition during Massa Medicata Fermentata fermentation.

In order to investigate the effect of apricot kernels on microbial community composition during Massa Medicata Fermentata (MMF) fermentation and to preliminarily explore whether it is related to amygdalin. In this paper, the structural characteristics of MMF and the composition of its bacterial and fungal communities during fermentation were determined. The results showed that both microscopy and infrared techniques could identify the structure of the apricot kernel in MMF and whether the kernel had been debitterized or not; the dominant bacterial phyla in MMF were Firmicutes and Proteobacteria, with the dominant bacterial genera being Staphylococcus and Bacillus, and the dominant fungal phylum was Ascomycota, with the dominant fungal genus being Aspergillus. Meanwhile, the effect of apricot kernels on the bacterial community in MMF was closely related to that of amygdalin. Apricot kernels inhibited the growth of a wide range of bacteria during the MMF fermentation but promoted the growth and reproduction of Firmicutes and Staphylococcus. In contrast, fermentation of MMF with debitterized apricot kernels significantly increased the bacterial diversity and richness while it inhibited the growth and reproduction of Firmicutes and Staphylococcus. In summary, amygdalin is a key player in regulating microbial community diversity that occurs during the fermentation process of MMF, apricot kernel was an essential component of MMF.