Increasing the activity and stability of biocidal-effective synthetic peptides

Antibiotics, which are used intensively against pathogens to protect food, animal, and human health, pose a threat to the environment and human health over time by causing residue, antibiotic resistance, and neurological damage. To solve these problems, researchers have turned to natural solutions that do not pose a threat to human and environmental health. Antimicrobial Peptides (AMPs) are structures naturally present in plants and organisms and are amino acid chains that can also be synthesized and produced synthetically. AMPs affect pathogens such as bacteria, viruses, fungi, and parasites and cause their death. With the rapid development of the Solid Phase Peptide Synthesis (SPPS) method in recent years, studies on AMPs have also accelerated. The SPPS method allows for the synthesis of synthetic peptides with high efficiency and speed within standard processes. Three peptides were synthesized using the SPPS method. The PW-2 peptide with anticoccidial properties and the PW-KC and KP-M peptides obtained by modifying the sequence of this peptide were synthesized. By using the preparative high-performance liquid chromatography (HPLC) system, by-products formed during the synthesis of peptides were purified. The structures of the obtained peptides were confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Anticoccidial activity studies were conducted against Eimeria oocysts to determine the effectiveness of the synthesized peptides on Eimeria oocysts. As a result of the studies, Eimeria oocysts were counted under a microscope using the quantitative fecal flotation method at 1 hour, 3 hours, 24 hours, and on the 7th day. According to these results, it was determined that among the three synthesized peptides, the KP-M peptide had the highest anticoccidial activity. Subsequently, the microencapsulation process of the KP-M peptide was carried out using the Spray Drying System (SDS), thereby increasing the stability of the KP-M peptide. Anticoccidial activity tests of the microencapsulation product diluted at various rates were conducted on Eimeria oocysts, and the results were compared with those of the KP-M peptide. The obtained results showed that the stability of the KP-M peptide increased by 25.17% as a result of microencapsulation.