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Beta-cypermethrin (β-CY) is an organic compound that is widely used as a synthetic pesticide in agriculture and family. Excessive accumulation of β-CY inevitably causes environmental pollution, which has led to food safety and human health concerns. Identification of microorganisms from food sources that are capable of β-CY biodegradation may help prevent pollution due to β-CY accumulation. Here, Gordonia alkanivorans GH-1, which was isolated from the traditional Sichuan fermented food, Pixian Doubanjiang, could not only degrade 82.76% of 50 mg/L β-CY at 96 h, but also degraded the intermediate degradation products including dibutyl phthalate (DBP), benzoic acid (BA) and phenol (Ph). This bacterial strain, thus, effectively improved the efficiency of removal of β-CY and its related metabolites, without being limited by toxic intermediates. Whole genome sequencing and transcriptomics analyses have demonstrated that the bacteria affected the transcription of genes related to cell response and material transport under the stress induced by β-CY, and thereby promoted degradation and transformation of β-CY. Moreover, a complete pathway of β-CY degradation is proposed based on the key genes involved in degradation. This study provides important theoretical significance and reference value for eliminating pesticide residues in agricultural products and food to ensure food safety., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Pickles are typical traditional Chinese fermented vegetables. Complex microbiota interacts throughout the fermentation and deterioration process. Minimal studies are available involving quorum sensing (QS) signaling in pickles. This study investigated the changes in the general pickle properties and microbial diversity at 4 d, 31 d, and 79 d. The QS signaling activity of various strains isolated at these key time points was screened using biosensor strains, while the types of signal molecules were further identified using UHPLC/QTOF-MS/MS. At 4 d, Lactobacillus represented the dominant genus, while Lactobacillus plantarum was identified as the bacteria with AI-2-producing ability. At 31 d, the dominant genus was also Lactobacillus, while the relative abundance of Pediococcus displayed a distinct increase. At this time point, L. plantarum represented the AI-2-producing bacteria, followed by Lactobacillus brevis, Pediococcus sp., Enterobacter sp., and Bacillus megaterium. At 79 d, Lactobacillus was displaced by Enterobacter as the dominant microorganisms, while the AI-2-producing bacteria were identified as L. plantarum, Enterobacter sp., B. megaterium, Klebsiella sp., and Staphylococcus sp. Moreover, AHL activity was only present in isolates from the 79-d brine and was identified as C4-HSL and C6-HSL. In addition, the luxS gene was amplified via cDNA reversely transcription from the total RNA extracted from the brine at all three time points using the L. plantarum luxS primers. The AHL-related genes were only amplified in the RNA of 79-d brine samples using Klebsiella pneumoniae- and Bacillus cereus-related primers. This study presented theoretical references for QS during pickle fermentation and deterioration., (Copyright © 2022. Published by Elsevier B.V.)

One elite γ-aminobutyric acid (GABA) producing strain of Saccharomyces cerevisiae SC125 was isolated and identified from Chinese traditional paocai. S. cerevisiae SC125 and Lactobacillus plantarum BC114 were used as cooperative species to ferment mulberry (Morus alba L.) and produce a novel beverage enriched with GABA. The GABA, organic acids and volatile compounds in different fermentation stages were determined by high-performance liquid chromatography (HPLC) and headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS). It was noted that coculture changed the profiles of flavor compounds in mulberry beverage. The tartaric and succinic acid contents increased to 1.34 g/L and 0.39 g/L, respectively. Lactic, malic, citric, and oxalic acid levels ranged between 0.92 and 2.56 g/L, and ethanol and glycerol were produced at 2.66 g/L and 1.81 g/L, respectively. More volatile compounds were detected in the coculture with significantly enhanced concentrations of fruity esters including ethyl caproate, ethyl propionate, butyl acetate, ethyl butyrate, ethyl caprylate and ethyl caprate, and alcohols of phenylethyl alcohol, 1-pentanol and 2-amino-1,3-propanediol. Also, a yield of 2.42 g/L GABA was achieved in the coculture. In conclusion, S. cerevisiae SC125 and L. plantarum BC114 coculture promotes the production of flavor compounds and GABA in mulberry beverage brewing., (Copyright © 2019 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

Beta-cypermethrin (β-CY) residues in food are an important threat to human health. Microorganisms can degrade β-CY residues during fermentation of fruits and vegetables, while the mechanism is not clear. In this study, a comprehensively investigate of the degradation mechanism of β-CY in a food microorganism was conducted based on proteomics analysis. The β-CY degradation bacteria Gordonia alkanivorans GH-1 was derived from fermented Pixian Doubanjiang. Its crude enzyme extract could degrade 77.11% of β-CY at a concentration of 45 mg/L within 24 h. Proteomics analysis revealed that the ester bond of β-CY is broken under the action of esterase to produce 3-phenoxy benzoic acid, which was further degraded by oxidoreductase and aromatic degrading enzyme. The up-regulation expression of oxidoreductase and esterase was confirmed by transcriptome and quantitative reverse transcription PCR. Meanwhile, the expression of esterase Est280 in Escherichia coli BL21 (DE3) resulted in a 48.43% enhancement in the degradation efficiency of β-CY, which confirmed that this enzyme was the key enzyme in the process of β-CY degradation. This study reveals the degradation mechanism of β-CY by microorganisms during food fermentation, providing a theoretical basis for the application of food microorganisms in β-CY residues. [Display omitted] • β-CY residues in food are harmful and should be degraded. • Food microorganisms were used to degrade β-CY residue in food. • The expression of pyrethroid degradation enzymes was upregulated. • Multi-omics analysis revealed the degradation mechanism of β-CY. • We found the esterase gene ge000280 and analyzed its expression in E. coli. [ABSTRACT FROM AUTHOR]