Raffinose, a plant galactoside, inhibits Pseudomonas aeruginosa biofilm formation via binding to LecA and decreasing cellular cyclic diguanylate levels

Abstract

Biofilm formation on biotic or abiotic surfaces has unwanted consequences in medical, clinical, and industrial settings. Treatments with antibiotics or biocides are often ineffective in eradicating biofilms. Promising alternatives to conventional agents are biofilm-inhibiting compounds regulating biofilm development without toxicity to growth. Here, we screened a biofilm inhibitor, raffinose, derived from ginger. Raffinose, a galactotrisaccharide, showed efficient biofilm inhibition of Pseudomonas aeruginosa without impairing its growth. Raffinose also affected various phenotypes such as colony morphology, matrix formation, and swarming motility. Binding of raffinose to a carbohydrate-binding protein called LecA was the cause of biofilm inhibition and altered phenotypes. Furthermore, raffinose reduced the concentration of the second messenger, cyclic diguanylate (c-di-GMP), by increased activity of a c-di-GMP specific phosphodiesterase. The ability of raffinose to inhibit P. aeruginosa biofilm formation and its molecular mechanism opens new possibilities for pharmacological and industrial applications.

Raffinose Induces Biofilm Formation by Streptococcus mutans in Low Concentrations of Sucrose by Increasing Production of Extracellular DNA and Fructan

“…in the human gut and has antiallergic properties in rats (21,35). Recently, raffinose was reported to inhibit the biofilm formation of Pseudomonas aeruginosa (36). In contrast, our study showed stimulatory effects of raffinose on biofilm formation by S. mutans in low concentrations of sucrose.…”

Searching for a potential antibacterial lead structure against bacterial biofilms among new naphthoquinone compounds

“…The bacterial activities in the initial phase of biofilm formation can also affect important phenotypes, such as colony morphology, matrix formation and swarming motility (Kim et al . ).…”

“…Our data indicate that a potential therapeutic mechanism may be targeting biofilm formation, particularly in the initial process of bacterial attachment on the surface and proliferation, which involves the initial adhesion of bacterial surface proteins to the plastic surface. The bacterial activities in the initial phase of biofilm formation can also affect important phenotypes, such as colony morphology, matrix formation and swarming motility (Kim et al 2016…”

Regulation of Seed Vigor by Manipulation of Raffinose Family Oligosaccharides in Maize and Arabidopsis thaliana

“…Despite years of study, it remains unclear whether galactinol, or any RFOs, are definitively required for, and directly involved in, seed vigor (Dierking and Bilyeu, 2009) or vegetative drought or cold tolerance (Amiard et al, 2003;Zuther et al, 2004). If required, the possible mechanisms of action (peripheral metabolic involvement [Kim et al, 2016], free radical scavenging [Nishizawa et al, 2008], sucrose crystallization inhibition [Leinen and Labuza, 2006]; water replacement [Martinez-Villaluenga et al, 2008], and the cellular component(s) affected [lipids, Hincha et al, 2003;proteins, Wendorf et al, 2004; general metabolic dampening, Sun and Leopold, 1997; or combinations of these]) remains obscure.…”