Zeng L, Noeparvar P, Burne RA, Glezer BS. Genetic characterization of glyoxalase pathway in oral streptococci and its contribution to interbacterial competition.
J Oral Microbiol 2024;
16:2322241. [PMID:
38440286 PMCID:
PMC10911100 DOI:
10.1080/20002297.2024.2322241]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Accepted: 02/16/2024] [Indexed: 03/06/2024] Open
Abstract
Objectives
To analyze contributions to microbial ecology of Reactive Electrophile Species (RES), including methylglyoxal, generated during glycolysis.
Methods
Genetic analyses were performed on the glyoxalase pathway in Streptococcus mutans (SM) and Streptococcus sanguinis (SS), followed by phenotypic assays and transcription analysis.
Results
Deleting glyoxalase I (lguL) reduced RES tolerance to a far greater extent in SM than in SS, decreasing the competitiveness of SM against SS. Although SM displays a greater RES tolerance than SS, lguL-null mutants of either species showed similar tolerance; a finding consistent with the ability of methylglyoxal to induce the expression of lguL in SM, but not in SS. A novel paralogue of lguL (named gloA2) was identified in most streptococci. SM mutant ∆gloA2SM showed little change in methylglyoxal tolerance yet a significant growth defect and increased autolysis on fructose, a phenotype reversed by the addition of glutathione, or by the deletion of a fructose: phosphotransferase system (PTS) that generates fructose-1-phosphate (F-1-P).
Conclusions
Fructose contributes to RES generation in a PTS-specific manner, and GloA2 may be required to degrade certain RES derived from F-1-P. This study reveals the critical roles of RES in fitness and interbacterial competition and the effects of PTS in modulating RES metabolism.
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