AKTIVITAS ANTIBAKTERI PEPTIDA KASEIN SUSU KAMBING HIDROLISIS OLEH PAPAIN TERHADAP Pseudomonas aeruginosa ANTIBACTERIAL ACTIVITY OF GOAT MILK CASEIN PEPTIDES HYDROLYZED BY PAPAIN ENZYME TOWARD Pseudomonas aeruginosa

Abstrak Susu kambing mengandung sekitar 3.4% protein, termasuk di dalamnya peptida bioaktif. Peptida bioaktif (contohnya peptida antibakteri) adalah fragmen protein spesifik yang bermanfaat bagi fungsi tubuh manusia dan bisa diperoleh melalui proses hidrolisis enzimatik. Penelitian mengenai peptida bioaktif dari susu kambing Indonesia masih belum banyak dilaporkan. Oleh karena itu tujuan dari penelitian ini adalah untuk menganalisis profil protein dan peptida dari kasein susu kambing Etawa yang dihidrolisis oleh papain dan menganalisis aktivitas antibakteri peptida terhadap bakteri Pseudomonas aeruginosa . Kasein diisolasi dari susu kambing segar dan dihidrolisis selama 0, 1, 3, 10, dan 15 menit pada 50 0 C dengan papain. Profil protein dan peptida dianalisis dengan metode Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) (konsentrasi gel 20%). Hasil analisis menunjukkan bahwa pita protein hasil hidrolisis menjadi semakin tipis seiring dengan bertambahnya waktu hidrolisis. Aktivitas antibakteri dari isolat kasein dan peptida hasil hidrolisis dianalisis menggunakan microplate reader selama 24 jam . Hasil analisis menunjukkan Isolat kasein dan peptida 3 menit menunjukkan aktivitas antibakteri dengan memperpanjang fase lag yang paling baik terhadap terhadap P. aeruginosa dibandingkan peptida lainnya. Kata kunci : antibakteri, kasein, peptida antibakteri, SDS-PAGE, susu kambing Abstract Goat milk contains approximately 3.4% protein, including bioactive peptides. Bioactive peptides (as example antibacterial peptides) are specific protein fragments that have beneficial effect for human body functions and can be obtained by enzymatic hydrolysis process. Research about bioactive peptides from Indonesian goat milk is still a few that has been reported. Therefore the objectives of this research were to analyze protein and peptides profile from Etawa goat milk casein hydrolyzed by papain, and to analyze antibacterial activity of the peptides toward Pseudomonas aeruginosa . Casein was isolated from fresh goat milk and hydrolyzed for 0, 1, 3, 10, and 15 minutes at 50 0 C by papain. Protein and peptides profile were analyzed by Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) method (20% gel). The results showed that protein bands of hydrolyzed casein were getting thinner as the hydrolysis process time increased. Antibacterial activity of casein isolate and hydrolyzed peptides were analyzed by using microplate reader for 24 hours. The results showed that casein isolate and peptides could inhibit the bacterial growth by extending the lag phase of bacterial growth. The casein isolate and peptides hydrolyzed for 3 minutes has the best antibacterial activity toward Pseudomonas aeruginosa. Keywords: antibacterial, antibacterial peptides, casein, goat milk, SDS-PAGE