Absence of inhibitory effects of two new glucanases on streptococcus mutans growth

Author(s)

Mateus Xavier-Queiroz ; Pedro Ricardo Vieira Hamann ^[2] ; Heidi Aarø Åmdal ^[3] ; Igor Polikarpov ^[4] ; Fernanda Cristina Petersen ^[5] ; Antônio Pedro Ricomini-Filho ^[6]

• Document type: Journal article
• Source: Braz. J. Oral Sci.; v. 23, 2025-01-10.

Abstract

Glucanohydrolases have shown promise in degrading exopolysaccharides in cariogenic biofilms, making them a potential strategy for biofilm control without disrupting the oral microbiota. However, their direct antimicrobial effects remain unclear. Aim To determine the antimicrobial activity on S. mutans of two newly discovered glucanases characterized by our group, PmGH87 (mutanase) from Prevotella melaninogenica and CoGH66 (dextranase) from Capnocytophaga ochracea, using a commercial dextranase from Penicillum sp. as a control. Methods Their effects on growth were assessed using a luciferase reporter system coupled with the promoter of the ldh gene in Streptococcus mutans. Results Quantification of optical density and luminescence over a 10-hour growth period revealed that the commercial dextranase exhibited inhibitory effects on S. mutans growth. However, these effects were neutralized by heat treatment, suggesting the presence of a heat-sensitive contaminant or an additional antimicrobial property associated with the commercial dextranase from Penicillum sp. On the other hand, the purified mutanase and dextranase enzymes had no inhibitory effect on S. mutans growth. Conclusion In conclusion, the absence of inhibitory effects on S. mutans growth by the newly discovered enzymes emphasizes their potential for biofilm control while preserving the delicate balance of the oral microbiota and preventing the emergence of resistance. (AU)

• FAPESP's process: 21/08780-1 - Enzymatic degradation of microbial biofilm exopolisacharides: structural biophysics, molecular biotechnology and synthetic biochemistry of CAZymes in search for new enzymatic tools for antimicrobial treatments
• Grantee: Igor Polikarpov
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 20/15092-1 - Bioactivity of enzymes in the degradation of the biofilm matrix to control oral diseases
• Grantee: Antônio Pedro Ricomini Filho
• Support Opportunities: Regular Research Grants
• FAPESP's process: 23/07897-8 - Biochemical and structural studies of CAZymes with potential in the degradation of exopolysaccharides from microbial biofilms
• Grantee: Pedro Ricardo Vieira Hamann
• Support Opportunities: Scholarships in Brazil - Post-Doctoral