Related Experiment Video

Updated: May 4, 2026

Monitoring Intraspecies Competition in a Bacterial Cell Population by Cocultivation of Fluorescently Labelled Strains
06:45

Monitoring Intraspecies Competition in a Bacterial Cell Population by Cocultivation of Fluorescently Labelled Strains

Published on: January 18, 2014

8.0K

Methylglyoxal resistance in Bacillus subtilis: contributions of bacillithiol-dependent and independent pathways

Pete Chandrangsu1, Renata Dusi, Chris J Hamilton

  • 1Department of Microbiology, Cornell University, Ithaca, NY, 14853-8101, USA.

Molecular Microbiology
|December 17, 2013
PubMed

Insights

Bacillus subtilis uses bacillithiol (BSH) to detoxify toxic methylglyoxal (MG) via glyoxalase enzymes, a process crucial for cell survival. This BSH-dependent pathway, involving cytoplasmic acidification, offers protection when glutathione is absent.

Area of Science:

  • Microbiology
  • Biochemistry
  • Cell Biology

Background:

  • Methylglyoxal (MG) is a toxic glycolysis byproduct damaging cellular components.
  • Glutathione typically detoxifies MG, but is absent in Firmicutes like Bacillus subtilis.
  • Bacillithiol (BSH) is identified as a major low-molecular-weight thiol in Firmicutes.

Purpose of the Study:

  • Investigate the role of BSH in methylglyoxal (MG) detoxification in Bacillus subtilis.
  • Identify MG resistance pathways in the absence of glutathione.
  • Elucidate the mechanisms of BSH-dependent and BSH-independent MG resistance.

Main Methods:

  • Cellular depletion of BSH by MG exposure.
  • Enzymatic assays for glyoxalase activity (GlxA, GlxB).
  • Measurement of intracellular pH and K+ efflux.
  • Genetic analysis of MG resistance pathways.

Main Results:

  • MG rapidly depletes BSH in Bacillus subtilis cells.
  • A BSH-dependent pathway using glyoxalase I (GlxA) and glyoxalase II (GlxB) converts MG to d-lactate.
  • The S-lactoyl-BSH intermediate activates the KhtSTU K+ efflux pump, causing protective cytoplasmic acidification.
  • Two BSH-independent pathways involving YdeA/YraA/YfkM (glyoxalase III homologues) and YhdN (aldo-keto reductase) also detoxify MG.

Conclusions:

  • Bacillithiol (BSH) is essential for methylglyoxal (MG) detoxification in Firmicutes.
  • Cytoplasmic acidification, mediated by BSH and K+ efflux, is critical for MG resistance.
  • Bacillus subtilis employs multiple, distinct pathways for MG detoxification, including BSH-dependent and BSH-independent mechanisms.

More Related Videos

Using Coculture to Detect Chemically Mediated Interspecies Interactions08:29

Using Coculture to Detect Chemically Mediated Interspecies Interactions

Published on: October 31, 2013

13.0K
Synthesis of Masarimycin, a Small Molecule Inhibitor of Gram-Positive Bacterial Growth09:10

Synthesis of Masarimycin, a Small Molecule Inhibitor of Gram-Positive Bacterial Growth

Published on: January 7, 2022

1.8K

Related Concept Videos

Mechanism of Antibiotic Resistance in MRSA01:25

Mechanism of Antibiotic Resistance in MRSA

Antibiotic resistance in bacteria arises when microorganisms evolve the ability to withstand drugs designed to kill them or inhibit their growth, rendering once-effective treatments useless. This phenomenon, driven by genetic change and selection under antibiotic exposure, poses a profound threat to modern medicine. Mechanisms include drug-inactivating enzymes (e.g., β-lactamases), efflux pumps that eject antibiotics, mutations altering antibiotic targets, decreased drug uptake, and...
219
Regulation of Bacterial Virulence01:28

Regulation of Bacterial Virulence

Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
76
Clinical Significance of Antibiotic Resistance01:25

Clinical Significance of Antibiotic Resistance

Methicillin-resistant Staphylococcus aureus (MRSA) presents a critical public health threat, arising from its capacity to resist β-lactam antibiotics due to acquisition of the mecA gene within the staphylococcal cassette chromosome mec (SCCmec). This gene encodes penicillin-binding protein 2a (PBP2a), which impairs binding efficacy of methicillin and other β-lactams. MRSA has evolved into distinct clonal lineages impacting humans and animals alike, reinforcing its significance within...
90
Defense Against Bacterial Pathogens01:31

Defense Against Bacterial Pathogens

The human immune system is a complex network of cells, tissues, and organs that work together to defend the body against bacterial infections. It consists of various immune cells, each playing a specific role in the defense mechanism.
Phagocytes
Phagocytes are the frontline soldiers of the immune system. They include neutrophils and macrophages. Neutrophils are the most abundant type of white blood cell and are quickly mobilized to the site of infection. Macrophages are larger cells that patrol...
3.0K
Other Glycolytic Pathways01:24

Other Glycolytic Pathways

The pentose phosphate pathway (PPP) operates in parallel with glycolysis, facilitating the metabolism of both pentoses and glucose. This pathway consists of two distinct phases: the oxidative and non-oxidative phases. While it does not directly generate ATP, the intermediates formed during the process can integrate into glycolysis, contributing to cellular energy metabolism when required.Oxidative Phase: NADPH ProductionThe oxidative phase of the pentose phosphate pathway is primarily...
1.1K
Development of Antibiotic Resistance01:30

Development of Antibiotic Resistance

Antibiotic resistance is a major public health concern that arises when bacteria evolve mechanisms to withstand the effects of antibiotic treatments. This resistance can be intrinsic, acquired through genetic mutations, or transferred between bacteria via horizontal gene transfer. The development of antibiotic resistance poses significant challenges in treating bacterial infections and necessitates ongoing research to develop new therapeutic strategies.Intrinsic resistance occurs when bacterial...
2.0K