Acid adaptive response of Alicyclobacillus acidoterrestris: A strategy to survive lethal heat and acid stresses

Ning Zhao; Junnan Xu; Lingxia Jiao; Miaomiao Liu; Tong Zhang; Jun Li; Xinyuan Wei; Mingtao Fan

doi:10.1016/j.foodres.2022.111364

Acid adaptive response of Alicyclobacillus acidoterrestris: A strategy to survive lethal heat and acid stresses

Food Res Int. 2022 Jul:157:111364. doi: 10.1016/j.foodres.2022.111364. Epub 2022 May 16.

Authors

Ning Zhao¹, Junnan Xu¹, Lingxia Jiao², Miaomiao Liu³, Tong Zhang¹, Jun Li¹, Xinyuan Wei¹, Mingtao Fan⁴

Affiliations

¹ College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China.
² School of Food Science, Henan Institute of Science and Technology, Xinxiang, Henan 453003, China.
³ School of Food and Biological Engineering, Shaanxi University of Science & Technology, Xi'an, Shaanxi 710021, China.
⁴ College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi 712100, China. Electronic address: fanmt@nwsuaf.edu.cn.

PMID: 35761625
DOI: 10.1016/j.foodres.2022.111364

Abstract

Alicyclobacillus acidoterrestris causes the spoilage of pasteurized acidic fruit juice, seriouslydecreasing quality and posing a significant safety concern. We previously discovered that acid adaptation could induce stress adaptive responses of A. acidoterrestris, however, the underlying mechanisms of this induction have not been fully elucidated. In this work, the effects of acid adaptation (pH = 3.0, 1 h) on intracellular pH (pH_i) and the morphophysiological properties of A. acidoterrestris under lethal heat and acid stresses were investigated, and gene expression profiles after acid adaptation were measured by transcriptomic analysis. The results showed that acid adaptation increased the pH_i of A. acidoterrestris cells in response to lethal stresses, enhanced membrane integrity, decreased surface shrinkage and roughness, and altered the Fourier transform infrared spectra profiles. After acid adaptation of A. acidoterrestris, 517 differentially expressed genes (DEGs) were detected. Consistent with resistance phenotypes, DEGs included genes related to cell surface modification and pH_i homeostasis. Specifically, the barrier function of cell membrane was strengthened during acid adaptation by increasing fatty acid (FA) chain length, promoting unsaturated FA biosynthesis, and maintaining balanced synthesis of zwitterionic and acidic phospholipids. To reduce excessive intracellular protons, cells upregulated glutamate decarboxylation, urease system, and branched-chain amino acid synthesis. Additionally, the nucleotide salvage pathway was activated, and homologous recombination, UvrD-mediated transcription-coupled, and ribonucleotide excision repair pathways were applied to repair DNA lesions. Sporulation metabolism was also induced. The findings of this study provide insight into the multiple layers of acid adaptive response strategies of A. acidoterrestris, with implications for the formulation of improved control measures in the fruit juice industry.

Keywords: Acid adaptation; Cell surface profiles; DNA lesions repair; Intracellular pH homeostasis; Transcriptome.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Alicyclobacillus*
Fruit and Vegetable Juices
Hot Temperature*

Supplementary concepts

Alicyclobacillus acidoterrestris