Evaluation of anti-biofouling potential of Viburnum opulus extracts / Evaluación del potencial anti bioincrustante de extractos de Viburnum opulus

In this study the in vitro investigation of the inhibitory effect of ethanol extract of Viburnum opulus L. bark sample on Streptococcus mutans planctonic cells and biofilm has been intended. A Scanning electron microscopy analysis has been performed in order to investigate the inhibitory effect of the extract on Streptococcus mutans biofilms. Furthermore, the Exopolysaccharide and dextran production of this bacteria have been identified in the presence of the extract. It has been found out that the bark extract with the concentration of 2,5 mg/mL is able to inhibit more than 50% of the cells in the different times development phases. According to this, the exopolymeric matrix on the biofilm surface disperses and the Exopolysaccharide and dextran production get lowered in the presence of bark extract compared to the control group. It is considered that this extract can be used as an alternative approach for the new chemotherapeutic strategies against tooth decay.

En este estudio se investigó el efecto inhibitorio in vitro del extracto de etanólico de una muestra de corteza de Viburnum opulus L. en biopelículas de células planctónicas de Streptococcus mutans. Se realizó un análisis de microscopía electrónica de barrido para investigar el efecto inhibitorio del extracto sobre las biopelículas de Streptococcus mutans. Además, se identificó la producción de exopolisacárido y dextrano de esta bacteria en presencia del extracto. Se descubrió que el extracto de corteza con una concentración de 2,5 mg/ml inhibió más del 50% de las células en las diferentes fases de desarrollo. Consecuentemente, la matriz exopolimérica en la superficie de la biopelícula se dispersa y la producción de exopolisacárido y dextrano se reduce en presencia de extracto de corteza en comparación con el grupo de control. Se sugiere que este extracto puede ser usado como un enfoque alternativo para las nuevas estrategias quimioterapéuticas contra la carie dental.

Inhibition of marine biofouling by aquatic Actinobacteria and coral-associated marine bacteria

Aims: Biofouling is a common biology phenomenon occuring on ship surface. This phenomenon has become serious threat in marine industries because of great economic loss. Tributyltin has been used to prevent biofouling, but it turned to cause the environmental problem. Therefore, the discovery of alternative environment-friendly compound is necessarily needed. Methodology and results: Five Actinobacteria isolates and fourteen marine bacteria isolates were tested against the biofilm formation of eight biofouling bacteria isolates that isolated from boat surface and the attachment of three biofouling diatoms (Amphora, Navicula, Nitzschia). Actinobacteria CW17 supernatant showed the broad spectrum activity against all fouling bacteria, whereas BC 11-5 supernatant was the only marine bacteria that capable to inhibit biofilm formation of V. neocaledonicus. Moreover, three representative diatoms attachment could be inhibited by the bioactive compounds produced by Actinobacteria and marine bacteria. CW01 supernatant showed broad spectrum and high activity against all three representative diatoms which is very promising. Molecular identification based on 16S rDNA gene sequence showed eight fouling bacteria isolates were biofilm-forming bacteria. Conclusions, significance and impact of study: This research showed aquatic Actinobacteria and coral-associated marine bacteria have the potential to prevent biofouling formation. Further studies are needed to purify and characterize these antibiofouling compounds for environmental application.