Microbial communities related to sensory attributes in Korean fermented soy bean paste (doenjang)

Abstract Various microbial communities play a role in generating the distinctive sensory characteristics of the traditional Korean soybean paste, doenjang . The objective of this study was to investigate the relationship between sensory characteristics and microbial communities in traditional doenjang . The results of the descriptive analysis revealed that some traditional doenjang (T1–T11) exhibited distinctive characteristics, such as fish sauce flavor, meju , bitterness, sourness, and saltiness, whereas the modified samples (M1–M3) demonstrated sweetness, umami , and an alcohol odor. According to the metagenomic analysis based on 16S rRNA gene sequencing, the phylum Firmicutes was the dominant bacterium in most doenjang . At the genus level, lactic acid bacteria (LAB) were frequently found in most doenjang . Among these LAB, the major genera of bacteria were Tetragenococcus in M2 (60.30%), T3 (91.20%), T8 (48.60%), and T9 (60.90%); Enterococcus in T1 (29.40%), T4 (34.10%), and T10 (50.50%); Leuconostoc in T7 (89.10%); and Lactobacillus in T9 (38.3%). The most frequently occurring non-LAB was Bacillus in M3 (50.10%), T5 (46.50%), and T6 (20.50%), and M1 and T2 contained Staphylococcus and Ochrobactrum as their major non-LAB, respectively. The results of a correlation analysis between the sensory attributes from the descriptive analysis and the microbial communities from 454 pyrosequencing provided an overview for the relationship between sensory characteristics and microbial communities. Ochrobactrum , Stenotrophomonas , Rhodobacteraceae , Proteus , and Luteimonas were found in samples that had a strong fish sauce characteristic. The presence of LAB— Tetragenococcus , Enterococcus , Pediococcus , Carnobacterium , and Weissella —was related to sourness. Enterococcus and Enterobacter were found in samples with a matured flavor and a soft mouthfeel, respectively. The overall results of the study demonstrate that microbial communities found in doenjang were closely related to distinct sensory attributes.