Evaluation of L-Asparaginase Purified from Pseudomonas Fluorescens as Inhibitor for Biofilm Producers in Dental Decays.

Background: This study aimed to assess Pseudomonas fluorescens-purified L-Asparaginase's effectiveness as a broad-spectrum inhibitor of biofilm producers in dental decays.

Methods: The 16S rRNA sequence was used to build a phylogenetic tree to calculate the evolutionary distance between the isolated bacterial strain SW3 and other species. The evolutionary history was inferred by using the neighbor-joining approach.

Results: The bacteria were identified from dental decays, including Staphylococcus aureus, Streptococcus mutans, Streptococcus oralis, and Streptococcus mitis. Each one of these isolates showed different degrees of biofilm development. Purified L-Asparaginase inhibited the most potent Gram-positive biofilm-forming bacteria (biofilm producers) with higher inhibition percentages against Streptococcus oralis and Streptococcus mitis, 65 - 73.8 % and 54.7 - 63%, respectively. The inhibition percentages increased with increasing concentration and reached up to 74 - 81% with Streptococcus oralis and 66 - 74% with Streptococcus mitis, while SW3 bacteria showed (100%). This strain was suggested SW3 (Pseudomonas spp.). Pseudomonas fluorescens bacterial strain isolated from rhizosphere soil produced extracellular L-Asparaginase when grown on as a substrate. L-Asparaginase was purified to homogeneity by using ammonium sulfate at 60% saturation, followed by gel filtration chromatography on a sephadex G-100 column, with a recovery yield of 49% and a purification fold of 2.22.

Conclusions: L-Asparaginase had a promising use for removing and avoiding biofilm growth, implying that it might be used in the dental industry in the future.