Promoting Beneficial and Inhibiting Undesirable Biofilm Formation with Mangrove Extracts

Abstract

The extracts of two mangrove species, Bruguiera cylindrica and Laguncularia racemosa, have been analyzed at sub-lethal concentrations for their potential to modulate biofilm cycles (i.e., adhesion, maturation, and detachment) on a bacterium, yeast, and filamentous fungus. Methanolic leaf extracts were also characterized, and MS/MS analysis has been used to identify the major compounds. In this study, we showed the following. (i) Adhesion was reduced up to 85.4% in all the models except for E. coli, where adhesion was promoted up to 5.10-fold. (ii) Both the sum and ratio of extracellular polysaccharides and proteins in mature biofilm were increased up to 2.5-fold and 2.6-fold in comparison to the negative control, respectively. Additionally, a shift toward a major production of exopolysaccharides was found coupled with a major production of both intracellular and extracellular reactive oxygen species. (iii) Lastly, detachment was generally promoted. In general, the L. racemosa extract had a higher bioactivity at lower concentrations than the B. cylindrica extract. Overall, our data showed a reduction in cells/conidia adhesion under B. cylindrica and L. racemosa exposure, followed by an increase of exopolysaccharides during biofilm maturation and a variable effect on biofilm dispersal. In conclusion, extracts either inhibited or enhanced biofilm development, and this effect depended on both the microbial taxon and biofilm formation step.

Genetic Elucidation of Quorum Sensing and Cobamide Biosynthesis in Divergent Bacterial-Fungal Associations Across the Soil-Mangrove Root Interface

“…Apart from the natural feature of keystones, biofilm also played an important role in regulating microbial interactions. Early evidence showed that biofilm could form in mangrove roots (Mallick et al, 2018;Glasenapp et al, 2019). Combined with the fact that endophytes were capable of forming mixedcommunity biofilms inside roots (van Overbeek and Saikkonen, 2016), we supposed a high potential of the mixed-community biofilm formation in the endosphere of the mangrove root, thereby providing a niche for intensive microbial inter-domain associations (Cai et al, 2019).…”

High-throughput screening of multifunctional nanocoatings based on combinations of polyphenols and catecholamines

“…S21A ), except for H10, H23, H25, and H30 for which bacterial survival rates were slightly lower than on non-coated PS (95%, 94%, 89%, and 90%, respectively). Although antibacterial activity has been reported for some plant phenolic compounds [ 9 , 21 , 40 , 41 ], it was also shown that these compounds could both enhance or inhibit the formation and growth of bacteria depending on the experimental conditions [ [40] , [41] , [42] , [43] , [44] , [45] ].…”

Non-Lethal Effects of N-Acetylcysteine on Xylella fastidiosa Strain De Donno Biofilm Formation and Detachment

“…It is worth noting that a reduced number of adhered cells did not guarantee a biofilm biomass reduction. Glasenapp et al [36] observed that although sub-lethal concentrations of mangrove extracts reduced microbial adhesion to the surfaces, they stimulated EPS production with a consequent increase in biofilm biomass.…”

“…Biofilm biomass was evaluated measuring the amount of cellular protein [36]. Briefly, two membranes for each treatment were transferred in 1 mL of phosphate buffered saline solution (PBS), and biofilm was removed from the membrane surface by 1 min vortex mixing, 2 min sonication (50% amplitude, in a water bath; Branson 3510, Branson Ultrasonic Corporation, Dunburry, CT, USA) followed by another 1 min of vortex mixing.…”