Aflatoxin B1 (AFB1), a pollutant of agricultural products, has attracted considerable attention in recent years, due to its potential impact on health. In the present study, Bacillus licheniformis (BL010) was demonstrated to efficiently degrade AFB1, reducing over 89.1% of the toxin content within 120 h. A crude enzyme solution of BL010 exhibited the highest degradation level (97.3%) after three induction periods. However, uninduced BL010 bacteria was not capable of reducing AFB1. Furthermore, high performance liquid chromatography (HPLC) analysis showed that while a cell-free extract caused a significant decrease in AFB1 content (93.6%, p < 0.05), cell culture fluid treatment did not significantly degrade AFB1. The biotransformation products of AFB1 were detected and further identified by quadrupole time-of-flight liquid chromatography–mass spectrometry (LC-Q-TOF/MS); these corresponded to a molecular formula of C₁₂H₁₄O₄. A sequence analysis of whole BL010 genes with a bioinformatics approach identified the secondary structures of two degrading enzymes (Chia010 and Lac010), providing an important basis for subsequent homology modeling and functional predictions.

Sesame flavour liquor is a traditional Chinese distilled spirit with fruity, sweaty, roasted sesame and floral aromas. High temperature Daqu production is one of the key processes in the formation of sesame flavour liquor. The composition and changes in the microbial community during the making of Daqu have a significant impact on the quality of Daqu liquor. In this study, microbial diversity based on high throughput sequencing technology was used to reveal the bacterial community structure and succession law in the four critical stages of high temperature Daqu production. The results show that Firmicutes had a significant advantage (76.7%‐98.2%) in the four stages as Proteobacteria and Actinobacteria reached peak values in the first and second periods, and decreased in the later periods. At the genus level, Kroppenstedtia, Lactobacillus, Weissella, Lentibacillus, Bacillus and Saccharopolyspora were detected as the main bacterial groups in the high temperature Daqu of Chinese sesame flavour liquor. The abundance of Lactobacillus and Weissella was greater than that of other microbes in the Daqu entry period. During the first Daqu flipping, the number of bacterial genera reached a peak in the production process. Then, the bacterial diversity continued to decrease until the last period, while Kroppenstedtia, Saccharopolyspora and Lentibacillus adapted to the high temperature environment and accumulated during the second Daqu flipping and the Daqu exit. This research used high throughput sequencing technology to reveal, for the first time, the bacterial composition and dynamic succession in high temperature Daqu production of Chinese sesame flavour liquor. This work will contribute to a deeper understanding of the correlation between the formation of flavour substances in sesame flavour liquor and the microorganisms used in its production. © 2019 The Institute of Brewing & Distilling

Tropical fruits are popular because of their unique, delicious flavors and good nutritional value. Polyphenols are considered to be the main bioactive ingredients in tropical fruits, and these exert a series of beneficial effects on the human gastrointestinal tract that can enhance intestinal health and prevent intestinal diseases. Moreover, they are distinct from the polyphenols in fruits grown in other geographical zones. Thus, the comprehensive effects of polyphenols in tropical fruits on gut health warrant in-depth review. This article reviews, first, the biological characteristics of several representative tropical fruits, including mango, avocado, noni, cashew apple, passion fruit and lychee; second, the types and content of the main polyphenols in these tropical fruits; third, the effects of each of these fruit polyphenols on gastrointestinal health; and, fourth, the protective mechanism of polyphenols. Polyphenols and their metabolites play a crucial role in the regulation of the gut microbiota, increasing intestinal barrier function, reducing oxidative stress, inhibiting the secretion of inflammatory factors and regulating immune function. Thus, review highlights the value of tropical fruits, highlighting their significance for future research on their applications as functional foods that are oriented to gastrointestinal protection.