Extracellular Phosphate Modulation and Polyphosphate Accumulation by Corynebacterium matruchotii and Streptococcus...

Area of Science:

• Oral microbiology
• Biochemistry
• Dental research

Background:

• Microbial ion exchange of calcium (Ca²⁺) and orthophosphate (P_i) influences enamel demineralization.
• Understanding oral microbiome's role in modulating Ca²⁺ and P_i is key for effective mineralization therapies.

Purpose of the Study:

• To investigate the capacity of oral bacteria, specifically *Corynebacterium matruchotii* and *Streptococcus mutans*, to modulate Ca²⁺ and P_i levels.
• To assess the potential of these bacteria in altering mineral solubility for improved oral health.

Main Methods:

• Orthophosphate (P_i) uptake was quantified using an ascorbic acid assay during bacterial growth.
• Calcium (Ca²⁺) levels in the medium were measured using ICP-OES.
• Bacterial polyphosphate (polyP) accumulation was detected via DAPI/polyP binding fluorescence.

Main Results:

• *Corynebacterium matruchotii* demonstrated significant P_i accumulation (3.84 mmol/L) and polyP formation.
• *Streptococcus mutans* showed no notable P_i uptake or polyP accumulation.
• Neither bacterial strain caused a significant reduction in medium Ca²⁺ levels.

Conclusions:

• *Corynebacterium matruchotii* possesses a substantial capacity for P_i uptake, linked to polyP synthesis.
• The findings suggest that P_i modulation by specific oral bacteria is a critical factor in oral health.
• Future in vitro assays for prevention technologies should consider incorporating oral bacteria with significant P_i uptake capabilities.