Screening Of Small Marine Antifouling Molecules Based On Metabonomics And Nano Antifouling Coating Technology

Marine biofouling can cause a variety of hazards,and there are nearly 200 species of marine fouling organisms in Chinese coastal areas.This not only destroys the aesthetics of ships and underwater artificial facilities,but also increases the fuel cost and maintenance cost,which has brought huge economic losses.Considering green and sustainable development,it is worth exploring whether there are natural metabolic small molecules that can repel the attachment of the larvae of contaminated organisms.Therefore,this study combined nano antifouling coating technology with metabolomics,screened marine antifouling small molecules and explored its antifouling mechanism.The composition of the early biofilm plays an important role in the later colonization of the larva of the large fouling organisms,so we take this as the starting point.Six types of carbon nanotubes(CNTs)and chlorinated rubber antirust paint were used to prepare composite antifouling coatings and 2 types of coatings with different antifouling properties were obtained.After hanging the plate,the antifouling score was carried out,and the coating was divided into two groups with different antifouling performance.The biofilm was sampled and compared with the metabolomics.They are respectively 57,17,20,29 CNTs as the representative of good antifouling performance coating and 60,66 CNTs as the representative of poor antifouling performance coating.After data preprocessing,basic statistics and visualization of metabolite content,screening of characteristic metabolites and advanced analysis of pathway correlation,small molecules with more content in the good coating were screened out.Theoretically,there is a metabolic module and its metabolic molecules which are not possessed by several kinds of fouling organisms and may inhibit the growth and reproduction of these fouling organisms to a certain extent.Based on the metabolic intertoxic theory,we determined the non-targeted metabolomics of six major contaminant organisms,namely barnacle,oysters,sea squirt,mussel,tube worm,and bryozoan,and mined the small molecules and pathway sets that do not participate in the metabolic processes of these six fouling organisms in the KEGG database,mapped the metabolic network,and selected representative intertoxic small molecules.The antifouling properties of the biofouling coating were preliminarily tested by the shallow sea immersion test of the sample antifouling paint by adding the intertoxic small molecules into the coating.In order to explore the antifouling mechanism of metabolic small molecules,the screened small molecules were added into the 2216 E medium for the culture of seawater microorganisms,to explore whether these small molecules could affect the normal growth of seawater microflora.At the same time,these two groups of small molecules were superimposed to try to explore whether the addition of the second group of small molecules had strengthening,weakening or other effects on the medium compared with the addition of only the first group of small molecules,so as to find the differences.There were some differences in the species,quantity and growth rate of the microflora.In summary,biofilm samples on the surface of the modified coating were collected in this study using GC-MS and LC-MS/MS non-targeted metabolomics.It was found that the contents of 43 metabolites in the better coating were significantly higher than those in the poorer coating.The metabolites involved in these different metabolic pathways mainly included ?-alanine metabolism,phenylalanine metabolism,pyrimidine metabolism,arginine and proline metabolism.At the same time,the metabolic components of six main contaminant species(barnacle,oyster,sea squirt,mussel,tube worm,bryozoan)were determined,and a total of 3935 potential intertoxic small molecules were found.By means of KEGG database and small molecule network diagram,five representative small molecules(D-glucose ? glycine ? L-alanine ? chitosan ?azithromycin dihydrate)were selected as coating additives,which could improve the antifouling performance.After adding small molecules into the 2216 E medium for the culture of the seawater sample,it can be seen that the addition of small molecules alone and the combination of small molecules can make a great difference in the structure and number of microflora.It is speculated that small molecules can affect the attachment or growth of the larvae by influencing the microbial community diversity on the surface and reshaping the interaction and alternation process among various biological communities in the biofilm.The small molecules found in this study are green and non-toxic,and friendly to the environment.Moreover,the selected small molecules are cheap and easy to expand the scale for the production and sales of major manufacturers.This study provides a new idea for the development of new antifouling technology based on metabonomics.