Discovery of Antibiofilm Activity of Elasnin against Marine Biofilms and Its Application in the Marine Antifouling Coatings

Abstract

Biofilms are surface-attached multicellular communities that play critical roles in inducing biofouling and biocorrosion in the marine environment. Given the serious economic losses and problems caused by biofouling and biocorrosion, effective biofilm control strategies are highly sought after. In a screening program of antibiofilm compounds against marine biofilms, we discovered the potent biofilm inhibitory activity of elasnin. Elasnin effectively inhibited the biofilm formation of seven strains of bacteria isolated from marine biofilms. With high productivity, elasnin-based coatings were prepared in an easy and cost-effective way, which exhibited great performance in inhibiting the formation of multi-species biofilms and the attachment of large biofouling organisms in the marine environment. The 16S amplicon analysis and anti-larvae assay revealed that elasnin could prevent biofouling by the indirect impact of changed microbial composition of biofilms and direct inhibitory effect on larval settlement with low toxic effects. These findings indicated the potential application of elasnin in biofilm and biofouling control in the marine environment.

Proteomics and Transcriptomics Uncover Key Processes for Elasnin Tolerance in Methicillin-Resistant Staphylococcus aureus

“…Elasnin was recently reported to exhibit antibiofilm activity against multiple Gram-positive and -negative bacteria and can be used as a coating agent in marine environments ( 5 ). Furthermore, a mechanistic study of its antibiofilm activity in MRSA has been recently performed, revealing that elasnin suppressed the production of virulence factors which resulted in a lower expression of extracellular EPS, cell wall, and membrane components, as well as peptidoglycan hydrolases, which are important for cell wall formation during cell division ( 7 ).…”

“…Elasnin was prepared according to a previously described protocol ( 5 ). Briefly, stock cultures of Streptomyces mobaraensis DSM 40847 were inoculated into AM4 medium (soybean powder [20 g/L], bacteriological peptone [2 g/L], glucose [20 g/L], soluble starch [5 g/L], yeast extract [2 g/L], NaCl [4 g/L], K 2 HPO 4 [0.5 g/L], MgSO 4 ·7H 2 O [0.5 g/L], CaCO 3 [2 g/L] [pH 7.8]) and incubated at 30°C for 5 days.…”

“…It was then suggested that elasnin and other structurally similar compounds (e.g., substituted-alpha pyrones) may be used as agents to treat chronic obstructive lung disease due to the destruction of lung tissue by leukocyte elastase ( 3 , 4 ). More recently, it was reported that elasnin also exhibited antibiofilm properties and is suitable for controlling biofilm formation and biofouling in the marine environment ( 5 , 6 ). For instance, elasnin could inhibit the biofilm formation of multiple strains of marine bacteria, such as Escherichia coli , Vibrio alginolyticus , Microbacterium esteraromaticum , and Staphylococcus aureus , and prevented the attachment of large biofouling organisms and larval settlement of Balanus amphitrite .…”

Anti-Larval and Anti-Algal Natural Products from Marine Microorganisms as Sources of Anti-Biofilm Agents

“…During the AF natural products project screening, the polyketide compound elasnin (51) highly produced by Streptomyces mobaraensis DSM 40847 exhibited strong biofilm inhibition activity against four marine bacterial Gram-positive strains Staphylococcus aureus B04, S. hominis N32, S. arlettae OM, and Microbacterium esteraromaticum N22 with MBIC 90 and MBIC 50 ranged from 2.5 to 5 µg/mL and 1.25 to 5 µg/mL, whereas three gram-positive strains Idiomarina sediminum N28, Pseudoalteromonas sp. L001, and Escherichia coli N57 with MBIC 90 of 5 to 10 µg/mL and MBIC 50 of 1.25 to 10 µg/mL, respectively [43]. The larval settlement of Balanus amphitrite was also effectively inhibited at concentrations above 12.5 µg/mL after 24 h exposure.…”

Elasnin Effectively Eradicates Daptomycin-Resistant Methicillin-Resistant Staphylococcus aureus Biofilms

“…Several studies have suggested that elasnin could be used to treat chronic obstructive lung disease caused by leukocyte elastase that damages the lung tissue ( 3 , 4 ). Recently, the antibiofilm activity of elasnin was explored, and it was reported that elasnin inhibited biofilm formation of multiple species in the marine environment, including some Gram-positive bacteria such as Staphylococcus aureus ( 5 , 6 ). Further investigation showed that elasnin did not only inhibit biofilm formation, but also effectively eradicated the biofilms of methicillin-resistant Staphylococcus aureus (MRSA) through the repression of the virulence regulon and interference of the cell division process (i.e., by suppressing the production of newly synthesized extracellular polymeric substance [EPS], cell wall and membrane components, and peptidoglycan hydrolases that are needed to finish cell wall formation) ( 7 ).…”