School of Material Science and Food Engineering, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan, 528402, China; Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, 510650, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangzhou, 510650, China.
School of Material Science and Food Engineering, University of Electronic Science and Technology of China, Zhongshan Institute, Zhongshan, 528402, China.
Food Microbiol. 2021 Sep;98:103762. doi: 10.1016/j.fm.2021.103762. Epub 2021 Feb 17.
Harmful levels of biogenic amines (BAs) are frequently identified in sufu. The microorganisms and mechanisms responsible for BA production in sufu, however, are not well documented. In this study, sufu samples were randomly obtained from various regions of China. Putrescine, tyramine, and histamine were quantitated as the most abundant BAs. According to the metagenome sequencing, the abundances and diversities of genes encoding the critical enzymes in BA production were acquired. The results showed that genes encoding arginine-, ornithine-, tryptophan-, and histidine decarboxylases were the predominant amino acid decarboxylase genes. Furthermore, 34 metagenome-assembled genomes (MAGs) were generated, of which 23 encoded at least one gene involved in BA production. Genetic analysis of MAGs indicated genera affiliated with Enterococcus, Lactobacillus-related, and Lactococcus were the major histamine-synthesizing bacteria, and tyrosine may be utilized by Bacillus, Chryseobacterium, Kurthia, Lysinibacillus, Macrococcus, and Streptococcus to product tyramine. The critical species involved in two putrescine-producing pathways were also explored. In the ornithine decarboxylase pathway, Lactobacillus-related and Veillonella were predicted to be the main performers, whereas Sphingobacterium and unclassified Flavobacteriaceae were the dominant executors in the agmatine deiminase pathway. The present study not only explained the BAs formation mechanism in sufu but also identified specific bacteria used to control BAs in fermented soybean products.
生物胺（BAs）在腐乳中经常被检测到，但其产生的微生物和机制尚未被充分记录。本研究中，我们随机获取了来自中国不同地区的腐乳样品。结果表明腐乳中含量最丰富的生物胺为腐胺、酪胺和组胺。根据宏基因组测序，我们获得了与 BA 产生相关的关键酶编码基因的丰度和多样性。结果表明，编码精氨酸、鸟氨酸、色氨酸和组氨酸脱羧酶的基因是主要的氨基酸脱羧酶基因。此外，我们共生成了 34 个宏基因组组装基因组（MAGs），其中 23 个编码至少一个与 BA 产生相关的基因。MAGs 的遗传分析表明，与肠球菌、乳杆菌相关和乳球菌属相关的细菌是主要的组胺合成菌，而酪氨酸可能被芽孢杆菌属、黄杆菌属、柯赫氏菌属、赖氨酸芽孢杆菌属、巨大芽孢杆菌属和链球菌属用于生产酪胺。我们还探讨了两种腐胺产生途径中涉及的关键物种。在鸟氨酸脱羧酶途径中，乳杆菌相关和魏氏菌被预测为主要执行者，而鞘氨醇单胞菌和未分类的黄杆菌科则是精氨酸脱氨酶途径中的主要执行者。本研究不仅解释了腐乳中 BA 的形成机制，还鉴定了可用于控制发酵大豆制品中 BA 含量的特定细菌。
