Antibacterial peptide for marine anticorrosion and antifouling and application thereof

Abstract

The invention belongs to the technical field of marine corrosion and protection, and discloses an antibacterial peptide for marine corrosion prevention and fouling prevention and application of the antibacterial peptide, the sequence of the antibacterial peptide is H-NIle-NVal-NLys-NLU-NPhe-NLU-NTyr-NArg-NSer-NTrp-NLU-NHis-NLU-NLU-NIle-NH2, the antibacterial and preservative effects of common corrosion inhibition bactericides such as quaternary ammonium salts, organic guanidines and aldehydes can be effectively enhanced, and the antibacterial peptide can be applied to marine corrosion prevention and fouling prevention. The generation of a corrosive biological membrane and the microbial corrosion rate can be effectively inhibited, the dosage of a bactericide can be reduced by 60% or above, and continuous antibacterial and anticorrosion for 30 days can be realized.

Description

Technical Field

[0001] This invention belongs to the field of marine corrosion and protection technology, specifically relating to an antimicrobial peptide for marine corrosion and fouling prevention and its application. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] In the field of marine antifouling and microbial corrosion control, traditional organic / inorganic bactericides (such as copper-based compounds and isothiazolinones) can inhibit microbial attachment in the short term, but they have problems such as high environmental toxicity, easy induction of drug resistance, and the need for frequent addition. Long-term use will damage the marine ecological environment, and the biofilm formed during the microbial corrosion process significantly weakens the penetration and efficacy of bactericides through physical barriers and microenvironment regulation.

[0004] AMPs are naturally occurring small-molecule peptides in organisms, possessing advantages such as broad-spectrum antibacterial activity, environmental friendliness, and low susceptibility to inducing drug resistance. They can disrupt the physical barriers of biofilms by breaking down EPS (extracellular polymeric substances), thereby significantly enhancing the permeability of bactericides to deep-seated microorganisms. Although AMPs have wide applications in clinical medicine and food preservation, their antibacterial activity is highly dependent on external environmental conditions and is easily affected by fluctuations in temperature, salinity, and pH. Especially in marine environments, the combined effects of high temperature, high salinity, and multiple hydrolytic enzymes severely reduce their stability and persistence, greatly limiting the application of AMPs in marine antibacterial and preservative fields. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an antimicrobial peptide for marine corrosion and fouling prevention and its application. By combining it with commonly used corrosion inhibitors and bactericides, it effectively inhibits the adhesion and corrosion of corrosive biofilms on material surfaces and significantly reduces the amount of bactericide required, thereby overcoming the technical bottlenecks of insufficient stability of existing antimicrobial peptides and the overuse of bactericides.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: In a first aspect, the present invention provides an antimicrobial peptide for marine corrosion and fouling prevention, the sequence of which is H. -NIle- NVal-NLys-NLeu-NPhe-NLeu-NTyr-NArg-NSer-NTrp-NLeu -NHis-NLeu- NLeu-NIle- NH2.

[0007] Secondly, the present invention provides the application of the aforementioned antimicrobial peptides for marine corrosion and fouling prevention in inhibiting the growth of corrosive biofilms and the rate of microbial corrosion.

[0008] Thirdly, the present invention provides the application of the aforementioned antimicrobial peptides for marine corrosion and fouling prevention as bactericidal synergists.

[0009] Fourthly, the present invention provides a composite bactericide, comprising the aforementioned antimicrobial peptides for marine corrosion and fouling prevention and a chemical bactericide.

[0010] Fifthly, the present invention provides the application of the aforementioned antimicrobial peptides or compound bactericides in marine microbial corrosion protection.

[0011] The beneficial effects achieved by one or more embodiments of the present invention described above are as follows: This invention provides a novel, long-acting antimicrobial peptide, DH-N15, which exhibits significant inhibitory effects against various bacterial species, including Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, and sulfate-reducing bacteria. It demonstrates good environmental compatibility and is unlikely to induce bacterial resistance. DH-N15 at concentrations of 10-100 nM can effectively enhance the antimicrobial and preservative effects of commonly used corrosion inhibitors and bactericides such as quaternary ammonium salts, organic guanidines, and aldehydes. It can effectively inhibit the formation of corrosive biofilms and the rate of microbial corrosion, reducing bactericide dosage by more than 60% and achieving continuous antimicrobial and preservative effects for up to 30 days. This invention holds promise for solving problems such as bacterial resistance, high costs, and environmental pollution caused by the overuse of corrosion inhibitors and bactericides. Attached Figure Description

[0012] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0013] Figure 1 The number of bacteria attached to the surface of carbon steel in culture media containing different concentrations of DH-1, DH-N15 and THPS after soaking for 14 days and 30 days, (a) DH-1, (b) DH-N15; Figure 2 The data show the weight loss of carbon steel in culture media containing different concentrations of THPS after soaking for 14 days and 30 days, (a) DH-1, (b) DH-N15; Figure 3 In Example 2, the number of bacteria attached to the surface of carbon steel in culture media containing different concentrations of DH-1, DH-N15 and ADBAC after soaking for 14 days and 30 days, (a) DH-1, (b) DH-N15; Figure 4 The data are for the weight loss of carbon steel in culture media containing different concentrations of ADBAC after soaking for 14 days and 30 days in Example 2, (a) DH-1, (b) DH-N15; Figure 5 In Example 3, the number of bacteria attached to the surface of carbon steel in culture media containing different concentrations of DH-1, DH-N15 and DCOIT after soaking for 14 days and 30 days, (a) DH-1, (b) DH-N15; Figure 6The data are the weight loss of carbon steel in culture media containing different concentrations of DCOIT after soaking for 14 days and 30 days in Example 3, (a) DH-1, (b) DH-N15; Detailed Implementation It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0014] To address the technical problems mentioned in the background art, the present invention provides an antimicrobial peptide for marine corrosion and fouling prevention, the sequence of which is H. -NIle-NVal-NLys-NLeu-NPhe-NLeu-NTyr -NArg-NSer-NTrp-NLeu-NHis- NLeu- NLeu-NIle- NH2.

[0015] Secondly, the present invention provides the application of the aforementioned antimicrobial peptides for marine corrosion and fouling prevention in inhibiting the growth of corrosive biofilms and the rate of microbial corrosion.

[0016] In some embodiments, the microorganism is Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, or sulfate-reducing bacteria.

[0017] Thirdly, the present invention provides the application of the aforementioned antimicrobial peptides for marine corrosion and fouling prevention as bactericidal synergists.

[0018] Fourthly, the present invention provides a composite bactericide, comprising the aforementioned antimicrobial peptides for marine corrosion and fouling prevention and a chemical bactericide.

[0019] In some embodiments, the chemical bactericide is tetrahydroxymethylphosphonic acid, quaternary ammonium salt bactericide, or isothiazolinone bactericide.

[0020] Preferably, the concentration of the antimicrobial peptide used for marine corrosion and fouling prevention is 1-150 nM.

[0021] More preferably, the concentration of the antimicrobial peptide used for marine corrosion and fouling prevention is 10-100 nM.

[0022] More preferably, the concentration of the antimicrobial peptide used for marine corrosion and fouling prevention is 50-100 nM.

[0023] Fifthly, the present invention provides the application of the aforementioned antimicrobial peptides or compound bactericides in marine microbial corrosion protection.

[0024] The present invention will be further described below with reference to the embodiments.

[0025] Example 1 The peptide-like molecule of this invention is designed and optimized based on the black soldier fly-derived antimicrobial peptide DH-1 (sequence: AIGVKTLGAGLGYSSGWSHGLI). First, the sequence is truncated by deleting threonine (Thr), alanine (Ala), and some glycine (Gly) residues, reducing the peptide chain length from 22 peptides to 15 peptides. Then, glycine at position 8 is replaced with phenylalanine (Phe), serine at position 14 is replaced with arginine (Arg), serine at position 18 is replaced with leucine (Leu), and glycine at position 20 is replaced with leucine (Leu). The guanidinium group of Arg increases the molecular positive charge (strengthening electrostatic adsorption with negatively charged microbial cell membranes), and the fatty chain of Leu enhances hydrophobicity (promoting membrane permeability). Subsequently, the free carboxyl group at the C-terminus of the modified linear peptide chain is converted into an amide group, eliminating the negative charge to enhance overall positive charge, while simultaneously shielding enzyme recognition sites and significantly improving environmental stability. Finally, the α-carbon side chain of the sequence-modified amino acid residues was transferred to the nitrogen atom of its main chain to construct a stable oligomeric-N-substituted glycine structure (H). -NIle-NVal-NLys-NLeu-NPhe-NLeu-NTyr-NArg-NSer- NTrp-NLeu-NHis-NLeu- NLeu-NIle- NH2), thereby obtaining a novel peptide-like DH-N15 that combines highly efficient antibacterial activity with long-lasting environmental adaptability, the structural formula of which is shown below:

[0026] To evaluate the synergistic antibacterial properties of the novel antimicrobial peptide DH-N15 and the traditional bactericide tetramethyl phosphonium sulfate (THPS), DH-1, DH-N15 (10, 50, 100 nM), and THPS (20, 80, 200 ppm) were compounded in different proportions to form a composite antimicrobial agent, and a static immersion experiment was conducted in Staphylococcus aureus bacterial solution using carbon steel.

[0027] The results show (see) Figure 1 , Figure 2 At 14 days, both 10-100 nM DH-1 and DH-N15 enhanced the antibacterial and preservative properties of THPS and showed a synergistic effect. Among them, 100 nM DH-N15 + 80 ppm THPS was more effective than 80 ppm and 200 ppm THPS used alone, saving more than 60% of fungicide. At 30 days, the activity and synergistic effect of DH-1 decreased, while DH-N15 still maintained a synergistic effect similar to that at 14 days and saved more than 60% of fungicide.

[0028] Example 2 To evaluate the synergistic antibacterial and preservative properties of the antimicrobial peptide DH-N15 and the quaternary ammonium bactericide alkyl dimethyl benzyl ammonium chloride (ADBAC), a composite system was constructed by adjusting the mixing ratio of DH-N15 (10, 50, 100 nM) and ADBAC (20, 75, 150 ppm). A 30-day static immersion experiment was conducted by placing carbon steel in Staphylococcus aureus bacterial solution. The results showed (see...) Figure 3 , Figure 4 Throughout the entire cycle, DH-N15 significantly enhances the antibacterial and corrosion-inhibiting effects of ADBAC, exhibiting a synergistic effect. Among them, 100 nM DH-N15 + 75 ppm ADBAC has the best effect. The use of 75 ppm and 150 ppm ADBAC alone can reduce the effective dosage of ADBAC from 150 ppm to 75 ppm, saving more than 50%.

[0029] Example 3 To evaluate the synergistic antibacterial properties of the novel antimicrobial peptide DH-N15 and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT), DH-N15 (10, 50, 100 nM) and DCOIT (10, 50, 100 ppm) were compounded in different proportions to form a composite antimicrobial agent, and a static immersion experiment was conducted in Staphylococcus aureus bacterial solution using carbon steel.

[0030] The results show (see) Figure 5 , Figure 6 At 14 days, 10-100 nM DH-N15 could slightly enhance the antibacterial and preservative properties of DCOIT. The antibacterial rate of 100 nM DH-N15 + 50 ppm DCOIT was comparable to that of 100 ppm DCOIT alone, saving about 50% of the DCOIT dosage. At 30 days, the synergistic effect of this compound system decreased, but it still maintained an antibacterial effect similar to that of 100 ppm DCOIT alone, and the dosage saving was still more than 50%.

[0031] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. An antimicrobial peptide for marine corrosion and fouling prevention, characterized in that: Its sequence is H -NIle-NVal-NLys- NLeu-NPhe-NLeu-NTyr-NArg-NSer-NTrp-NLeu-NHis-NLeu- NLeu-NIle- NH2.

2. The application of the antimicrobial peptides for marine corrosion and fouling prevention as described in claim 1 in inhibiting the growth of corrosive biofilms and the rate of microbial corrosion.

3. The application according to claim 2, characterized in that: The microorganisms mentioned are Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, or sulfate-reducing bacteria.

4. The use of the antimicrobial peptides for marine corrosion and fouling prevention as described in claim 1 as bactericidal synergists.

5. A compound bactericide, characterized in that: Includes the antimicrobial peptides and chemical bactericides for marine corrosion and fouling prevention as described in claim 1.

6. The compound bactericide according to claim 5, characterized in that: The chemical bactericides are tetrahydroxymethyl phosphate, quaternary ammonium salt bactericides, and isothiazolinone bactericides.

7. The compound bactericide according to claim 5, characterized in that: The concentration of the antimicrobial peptides used for marine corrosion and fouling prevention is 1-150 nM.

8. The compound bactericide according to claim 7, characterized in that: The concentration of the antimicrobial peptides used for marine corrosion and fouling prevention is 10-100 nM.

9. The compound bactericide according to claim 8, characterized in that: The concentration of the antimicrobial peptides used for marine corrosion and fouling prevention is 50-100 nM.

10. The application of the antimicrobial peptide of claim 1 or the composite bactericide of any one of claims 6-9 in marine microbial corrosion protection.

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