Activation of the chromosomally encoded mazEFBif locus of Bifidobacterium longum under acid stress

Wei, Yijun; Lu, Ye; Liu, Dianbin; Zhang, Zhuo-Yang; Liu, Chang; Guo, Xia

doi:10.1016/j.ijfoodmicro.2015.04.028

Cited by 10 publications

(7 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The activity of the toxin can be neutralized by forming a protein complex with its cognate antitoxin (30,37). Our results confirmed that the mazF homologue (BLJ_811) present in the chromosome of the JDM301 strain encodes a toxic protein (MazF 1 Bif ), which forms a complex with its cognate antitoxin, encoded by the adjacent mazE gene (BLJ_812) (10).…”

Section: Discussionsupporting

confidence: 76%

See 1 more Smart Citation

Physical and Functional Interplay between MazF ₁ ^Bif and Its Noncognate Antitoxins from Bifidobacterium longum

Wei

Yang

et al. 2017

Appl Environ Microbiol

View full text Add to dashboard Cite

strain JDM301, a widely used commercial strain in China, encodes at least two MazEF-like modules and one RelBE-like toxin-antitoxin (TA) system in its chromosome, designated MazEF, MazEF, and RelBE, respectively. Bacterial TA systems play an important role in several stress responses, but the relationship between these TA systems is largely unknown. In this study, the interactions between MazF and MazE or RelB were assessed in strain JDM301. MazF caused the degradation of mRNA, and its toxicity was inhibited by forming a protein complex with its cognate antitoxin, MazE Notably, MazF toxicity was also partially neutralized when jointly expressed with noncognate antitoxin MazE or RelB Our results show that the two noncognate antitoxins also inhibited mRNA degradation caused by MazF toxin. Furthermore, the physical interplay between MazF and its noncognate antitoxins was confirmed by immunoprecipitation. These results suggest that MazF can arrest cell growth and that MazF toxicity can be neutralized by its cognate and noncognate antitoxins. These results imply that JDM301 uses a sophisticated toxin-antitoxin interaction network to alter its physiology when coping with environmental stress. Although toxin-antitoxin (TA) systems play an important role in several stress responses, the regulatory mechanisms of multiple TA system homologs in the bacterial genome remain largely unclear. In this study, the relationships between MazEF and the other two TA systems of strain JDM301 were explored, and the interactions between MazF and MazE or RelB were characterized. In addition, the mRNA degradation activity of MazF was demonstrated. In particular, the interaction of the toxin with noncognate antitoxins was shown, even between different TA families (MazF toxin and RelB antitoxin) in JDM301. This work provides insight into the regulatory mechanisms of TA systems implicated in the stress responses of bifidobacteria.

show abstract

Section: Discussionsupporting

confidence: 76%

“…Bif and RelE Bif completely neutralized their cognate toxins MazF 2 Bif and RelE Bif , respectively (10,34,35). We speculate that in the original host, MazF 1…”

Section: Bif and Mazementioning

confidence: 85%

Physical and Functional Interplay between MazF ₁ ^Bif and Its Noncognate Antitoxins from Bifidobacterium longum

Wei

Yang

et al. 2017

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…However, during the industrial manufacturing processes and passage through the digestive tract of the host, bifidobacteria encounter various types of stress, which can reduce bifidobacterial viability and probiotic effects. In particular, bifidobacteria used as probiotics, need to survive the acid barrier of the stomach [2]. The acid barrier represents a major challenge for probiotics.…”

Section: Introductionmentioning

confidence: 99%

Adaptational changes in physiological and transcriptional responses of Bifidobacterium longum involved in acid stress resistance after successive batch cultures

et al. 2019

View full text Add to dashboard Cite

Bifidobacterium inhabiting the human and animal intestinal tract is known for its health-promoting effect. Tolerance to acid stress is crucial for bifidobacteria to survive and then exert their beneficial effects in the gut. A long-term adaptation in successive batch cultures was used as evolutionary engineering strategy to improve acid stress tolerance in an industrial probiotic strain, B. longum JDM301. Its derivative, JDM301AR showed higher resistance to several stress conditions, including acid stress than the parental strain, JDM301. To better understand bifidobacterial acid stress response, the changes of fatty acid (FA) in cell membrane of these two strains were determined. A shift in the production of FA in cell membrane, characterized by increased C14:0 was found, when JDM301AR was exposed to low-pH environment. It was implied that the increased production of C14:0 is associated with the acquisition of acid-tolerant phenotype for JDM301AR. High-throughput RNA-sequencing was performed to analyze the changes of gene expression profile after acid-exposure. The transcriptional profiles of JDM301AR and JDM301 under normal condition and acid stress were compared to reveal the different acid response between them. A total of 5 genes involved in FA metabolism were upregulated and no downregulated genes were found in response to acid stress in JDM301AR. The up-regulated BLJ_0565 and BLJ_1105 may play important roles in the modification of membrane FA composition of JDM301AR after acid exposure. Overall, these results suggested that successive batch cultures induced the acid stress tolerance of B. longum involved in transcriptional and physiological responses, including modification of cell wall and cell membrane, metabolism of amino acid and neutralization of internal pH by strengthening NH3 production and transport.

show abstract

“…Gene rbfA encoding ribosome-binding factor was up-regulated by 2.53 times, and this gene in Lactobacillus plantarum NMGL2 (recently reassigned as Lactiplantibacillus plantarum NMGL2) has been reported to be involved in the response to acid stress and cold stress [ 72 ]. Gene mazF was up-regulated by 2.25 times in liquid-state fermented cells, and this gene has been found to be activated under acid stress in Bifidobacterium longum [ 73 ]. Gene nagB encoding glucosamine-6-phosphate deaminase was up-regulated by 2.08 times, and this enzyme might be associated with acid stress response of Lactobacillus casei Zhang (recently reassigned as Lacticaseibacillus paracasei Zhang) [ 30 ].…”

Section: Resultsmentioning

confidence: 99%

Differences in Acid Stress Response of Lacticaseibacillus paracasei Zhang Cultured from Solid-State Fermentation and Liquid-State Fermentation

Zhu

Yang

et al. 2021

Microorganisms

View full text Add to dashboard Cite

Liquid-state fermentation (LSF) and solid-state fermentation (SSF) are two forms of industrial production of lactic acid bacteria (LAB). The choice of two fermentations for LAB production has drawn wide concern. In this study, the tolerance of bacteria produced by the two fermentation methods to acid stress was compared, and the reasons for the tolerance differences were analyzed at the physiological and transcriptional levels. The survival rate of the bacterial agent obtained from solid-state fermentation was significantly higher than that of bacteria obtained from liquid-state fermentation after spray drying and cold air drying. However, the tolerance of bacterial cells obtained from liquid-state fermentation to acid stress was significantly higher than that from solid-state fermentation. The analysis at physiological level indicated that under acid stress, cells from liquid-state fermentation displayed a more solid and complete membrane structure, higher cell membrane saturated fatty acid, more stable intracellular pH, and more stable activity of ATPase and glutathione reductase, compared with cells from solid-state fermentation, and these physiological differences led to better tolerance to acid stress. In addition, transcriptomic analysis showed that in the cells cultured from liquid-state fermentation, the genes related to glycolysis, inositol phosphate metabolism, and carbohydrate transport were down-regulated, whereas the genes related to fatty acid synthesis and glutamate metabolism were upregulated, compared with those in cells from solid-state fermentation. In addition, some genes related to acid stress response such as cspA, rimP, rbfA, mazF, and nagB were up-regulated. These findings provide a new perspective for the study of acid stress tolerance of L. paracasei Zhang and offer a reference for the selection of fermentation methods of LAB production.

show abstract

Activation of the chromosomally encoded mazEFBif locus of Bifidobacterium longum under acid stress

Cited by 10 publications

References 47 publications

Physical and Functional Interplay between MazF ₁ ^Bif and Its Noncognate Antitoxins from Bifidobacterium longum

Physical and Functional Interplay between MazF ₁ ^Bif and Its Noncognate Antitoxins from Bifidobacterium longum

Adaptational changes in physiological and transcriptional responses of Bifidobacterium longum involved in acid stress resistance after successive batch cultures

Differences in Acid Stress Response of Lacticaseibacillus paracasei Zhang Cultured from Solid-State Fermentation and Liquid-State Fermentation

Contact Info

Product

Resources

About

Activation of the chromosomally encoded mazEFBif locus of Bifidobacterium longum under acid stress

Cited by 10 publications

References 47 publications

Physical and Functional Interplay between MazF 1 Bif and Its Noncognate Antitoxins from Bifidobacterium longum

Physical and Functional Interplay between MazF 1 Bif and Its Noncognate Antitoxins from Bifidobacterium longum

Adaptational changes in physiological and transcriptional responses of Bifidobacterium longum involved in acid stress resistance after successive batch cultures

Differences in Acid Stress Response of Lacticaseibacillus paracasei Zhang Cultured from Solid-State Fermentation and Liquid-State Fermentation

Contact Info

Product

Resources

About

Physical and Functional Interplay between MazF ₁ ^Bif and Its Noncognate Antitoxins from Bifidobacterium longum

Physical and Functional Interplay between MazF ₁ ^Bif and Its Noncognate Antitoxins from Bifidobacterium longum