Project description:The spores of A. acidoterrestris cryopreserved at -80 ℃ were activated by inoculating in AAM medium and cultured at 45 ℃ to logarithmic phase [19]. The activated bacterial suspension was centrifuged and resuspended into pH 2.0, 2.5, 3.0, and 4.0 (Control) medium, which were correspondingly cultured in medium for 20 and 60 minutes, respectively. Scanning electron microscopy was used to monitor the bacterial activity and morphology different acid stress.Alicyclobacillus acidoterrestris (A. acidoterrestris) causes pasteurized acidic juice spoilage, resulting in a significant decline of juice quality, and causing economic losses. Exploration of A. acidoterrestris in response to acid stress could help control contamination caused by the bacteria. In this study, the mechanism of A. acidoterrestris in response to acid stress was studied by quantitative phosphoproteomics technique. Result showed that the phosphorylation of 40 proteins in A. acidoterrestris were closely related to the regulation of acid stress. The KEGG pathway enrichment analysis showed that the quorum sensing pathway which might involved in the perception of A. acidoterrestris was mainly enriched. we found that the up-regulation of Spo0A and YidC phosphorylation, which may resist acid stress by forming spores. The phosphorylation level of pyruvate kinase increased, which may improve bacterial acid stress resistance through formation of energy supply. The phosphorylation level of ABC transporter permease was significantly up-regulated, which may be part of the cell adaptation adjustment and contribute to the survival of A. acidoterrestris under acid stress. In summary, the molecular mechanism of acid stress regulation of A. acidoterrestris was proposed via quantitative phosphoproteomics, which provided a theoretical and experimental basis for further investigation acid resistance mechanism of A. acidoterrestris.
