Dextranase from Arthrobacter oxydans KQ11-1 inhibits biofilm formation by polysaccharide hydrolysis

Abstract

Dental plaque is a biofilm of water-soluble and water-insoluble polysaccharides, produced primarily by Streptococcus mutans. Dextranase can inhibit biofilm formation. Here, a dextranase gene from the marine microorganism Arthrobacter oxydans KQ11-1 is described, and cloned and expressed using E. coli DH5α competent cells. The recombinant enzyme was then purified and its properties were characterized. The optimal temperature and pH were determined to be 60°C and 6.5, respectively. High-performance liquid chromatography data show that the final hydrolysis products were glucose, maltose, maltotriose, and maltotetraose. Thus, dextranase can inhibit the adhesive ability of S. mutans. The minimum biofilm inhibition and reduction concentrations (MBIC and MBRC) of dextranase were 2 U ml and 5 U ml, respectively. Scanning electron microscopy and confocal laser scanning microscope (CLSM) observations confirmed that dextranase inhibited biofilm formation and removed previously formed biofilms.

DexA70, the Truncated Form of a Self-Produced Dextranase, Effectively Disrupts Streptococcus mutans Biofilm

“…Since dextran is the major component of S. mutans biofilm EPS, dextranase and mutanase from various bacterial sources have been used to treat dental biofilms. However, most of them had little effect ( Pleszczynska et al, 2010 ; Wiater et al, 2011 ; Wang et al, 2016 ).…”

Removing Dental Plaque Biofilm: A Review of Dextranases

“…When dextranase was added, S. mutans also cannot aggregate, thereby the formation of dental plaque biofilm was reduced significantly [40]. Arthrobacter oxydans KQ11-1 9 91.10±0.05 [46] Penicillium sp. 1 9.93±0.29 [39] Xiaohua Lai isolated the marine bacterium Catenovulum agarivorans MNH15 that could secret dextranase.…”

“…Moreover, removal rate was over 4 times higher than the mixture of dextranase and mutanase [42]. At present, most of the oral care products on the market are added with antibacterial agents such as alcohol, lysozyme, while products containing non-antibacterial dextranase are rare [43][44][45][46]. Some companies in the United States and Japan are mainly producing oral care products containing dextranase.…”

Profile of the Intervention Potential of the Phylum Actinobacteria Toward Quorum Sensing and Other Microbial Virulence Strategies

“…Arthrobacter oxydans KQ11-1 derived dextranase displayed MBIC 50 and MBIC 90 values of 2 U/m1 and 6 U/ml, respectively toward Streptococcus mutans biofilm. The MBRC 50 against preformed Streptococcus mutans biofilm was 5 U/ml and the dextranase decreased the thickness of the biofilm up to 36.67 μm (Wang et al, 2016).…”