No abstract

The aim of this study is to isolate the antioxidative peptide from Spirulina platensis. Peptide was obtained by proteolytic digestion, ultrafiltration, fractionation by RP-HPLC, identified by LC-MS/MS-MASCOT Distiller and measured its antioxidant activity by DPPH (2.2-Diphenyl-1-picrylhydrazyl) assay. Results showed that thermolysin was the most effective enzyme to digest this algae. The active peptide PheSer-Glu-Ser-Ser-Ala-Pro-Glu-Gln-His-Tyr (m/z 1281.51) was identified and synthetized, which exhibited 45.98 ± 1.7% at concentration 128.15 µg/mL. Therefore, S. platensis is indicated as a potential therapeutic source for combating oxidative stress.

Pakan merupakan salah satu komponen penting yang menentukan keberhasilan akuakultur, terutama sebagai penyedia energi dalam metabolisme ikan. Namun, hingga saat ini pakan menyita 60-70% dari keseluruhan total biaya produksi, terutama sistem budidaya intensif sehingga perlu dilakukan formulasi pakan menggunakan bahan baku lokal sebagai alternatif yang memiliki kandungan nutrisi tinggi dan harga lebih terjangkau dari pakan komersial. Penelitian menggunakan tepung tulang ikan sebagai bahan utama, dengan penambahan tepung lainnya dan terbagi menjadi 4 perlakuan (P1, P2, P3 dan P4) dengan penambahan pakan pabrik sebagai kontrol. Hasil penelitian menunjukkan bahwa pakan dengan perlakuan P4 memiliki karakteristik fisis dan kimiawi terbaik, dengan daya rekat, daya apung dan daya tahan dalam air yang menyerupai ketahanan pakan pabrik. Keseluruhan perlakuan pakan memiliki total energi lebih dari 1 kkal / gram dengan konversi harga lebih murah >10% dibandingkan pakan buatan pabrik, sehingga dapat disimpulkan bahwa formulasi pakan lokal hasil penelitian ini dapat digunakan sebagai alternatif pakan buatan komersial.

Chlorella sorokiniana is an edible microalga known for its high protein content with a balanced amino acid composition, nutritional value, beneficial health effect, and natural antioxidant. The enzymatic assays was used to extract the peptides of C. sorokiniana which was an uncommon method to test the antioxidant activity. In this research, protein of C. sorokiniana was extracted, purified, and hydrolyzed in several enzymes and kept at 37°C for 16h. Hence, enzymatic hydrolysate <3kDA was fractionated into 11 portions (C0%, C10%, to C100%) by using offline Strong Cation Exchange Chromatography (SCX) and their antioxidant activity was tested using DPPH (2.2-diphenyl-1-picrylhydrazyl) radical scavenging assay. The results indicated that C80%, contributed to the highest free DPPH scavenging on C. sorokiniana hydrolysate with the inhibition of 22.04%. Furthermore, to find the candidate peptides, this fraction was injected into LC-MS/MS for characterization of it's DPPH inhibitation. LSSATSAPS (m/z 1638,78) and AGLYGHPQTQEE (m/z 1328.59) are peptides that were identified and confirmed by LC-MS/MS. The molecular docking study was conducted to provide the binding simulation between these peptides and the ROS1 as the receptor. In conclusion, our results suggested that the aforementioned peptides were attached to ROS1 binding site and contributed to its potential antioxidant activity.