Konsentrat protein ikan (KPI) adalah bentuk protein kering yang diekstrak dari daging ikan menggunakan pelarut etanol. Tujuan penelitian ini adalah karakterisasi konsentrat protein ikan sunglir yang diekstrak menggunakan pelarut etanol. Bahan utama yang digunakan dalam penelitian ini adalah daging ikan sunglir dan pelarut etanol teknis. Tahapan penelitian meliputi (1) ekstraksi KPI menggunakan pelarut etanol 90% dengan perbandingan 1 : 3 selama 3 jam (2) menentukan standar mutu KPI ikan sunglir dan analisis asam amino. Data yang diperoleh dibahas secara deskriptif. Hasil penelitian menunjukkan bahwa nilai rata-rata rendemen KPI berkisar 20%. Karakteristik sesuai standar FAO 1976 meliputi kadar protein (85,34%), kadar lemak (3,28%), bau (2,11 : bau ikan kuat) dan derajat putih (53,54%) sehingga tergolong KPI tipe B. Analisis kadar air (6,34%), kadar abu (7,47%), sifat fungsional: daya serap minyak (2,48 g/g) dan daya serap air (2,02 ml/g). KPI mengandung 9 asam amino esensial dan 6 asam amino non esensial.

By product that rich in protein such as fish roes are potential as raw material for protein concentrate. This research aimed to utilize skipjack roes to produce protein concentrate and to characterize its functional properties. The method used to extract protein was defatting method using isopropyl alcohol and ethanol with extraction times of 1, 2, and 3 hours.  The results showed that skipjack roes contained 19.81% of protein, 3.41% of fat, 71.32% of moisture, 2.04% of ash, and 1.53% of carbohydrate (by difference). Defatting method using isopropyl alcohol for 3 hours produced the best roe protein concentrate (RPC).  The product meets to the quality requirements of fish protein concentrate type B, contained protein and fat of 71.79% and 2.78%, respectively. This product also had functional properties as follows: water absorption capacity (1.57 ml/g), oil absorption capacity (1.82 g/g), emulsion capacity (81.65%), bulk density (0.51 g/ml), foaming capacity (1.90 ml), foaming stability (0.22 ml) and protein digestibility (95.86%).  Lysine and leucine became the major essential amino acid of RPC, with values were 70.76 and 64.91 mg/g protein, respectively. The composition of amino acids of RPC skipjack consisted of 8 essentials amino acids, 5 non-essentials amino acids and 2 semi-essentials amino acids. Keywords: extraction, fish roe skipjack, roe protein concentrate

Abstract. Balansa W, Wodi SIM, Rieuwpassa FJ, Ijong FG. 2020. Agelasines B, D and antimicrobial extract of Agelas sp. from Tahuna Bay, Sangihe Islands, Indonesia. Biodiversitas 21: 699-706. The alarming growth of antibiotic-resistant bacteria necessitates the discovery of new antibiotics including those for combating life-threatening ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter sp) and fish pathogenic bacteria. This study aimed to identify antimicrobial compounds from an extract of a marine sponge collected from Enepahembang coral reef, Sangihe Islands, North Sulawesi, Indonesia. The sponge was identified by DNA barcoding as Agelas sp. and its extract was evaluated against three ESKAPE bacteria (S. aureus, K. pneumoniae, and A. baumannii) and three fish pathogenic bacteria (A. hydrophila, Edwardsiella tarda and Vibrio parahaemolyticus), using the standard disk diffusion method. It showed moderate to strong antimicrobial activity against S. aureus (25.3 mm), K. pneumoniae (15.5 mm), A. baumannii (20.2 mm), A. hydrophila (20.5 mm), E. tarda (22.4 mm) and A. salmonicida (21.2 mm). The extract was isolated by chromatographic techniques (column chromatography, flash chromatography, and high-performance liquid chromatography). The structures and relative stereochemistry of the two compounds were elucidated by HRESIMS, 1D and 2D NMR data analysis as well as by comparison with reported values. Unfortunately, limited amount of the pure compounds prevented us from further evaluating their antimicrobial activity against the test bacteria. Nevertheless, the crude extract's strong antimicrobial activity, especially against the test Gram-negative bacteria, suggests the importance of this finding in light of the recent antimicrobial drug scarcity but rapid antimicrobial resistance and the emerging paradigm of antimicrobial drug modification, redirection and/or repurposing for discovering new antibiotics particularly against the life-threatening Gram-negative bacteria.

The potential of sponge-associated bacteria for the biosynthesis of natural products with antibacterial activity was evaluated. In a preliminary screening 108 of 835 axenic isolates showed antibacterial activity. Active isolates were identified by 16S rRNA gene sequencing and selection of the most promising strains was done in a championship like approach, which can be done in every lab and field station without expensive equipment. In a competition assay, strains that inhibited most of the other strains were selected. In a second round, the strongest competitors from each host sponge competed against each other. To rule out that the best competitors selected in that way represent similar strains with the same metabolic profile, BOX PCR experiments were performed, and extracts of these strains were analysed using metabolic fingerprinting. This proved that the strains are different and have various metabolic profiles, even though belonging to the same genus, i.e. Bacillus. Furthermore, it was shown that co-culture experiments triggered the production of compounds with antibiotic activity, i.e. surfactins and macrolactin A. Since many members of the genus Bacillus possess the genetic equipment for the biosynthesis of these compounds, a potential synergism was analysed, showing synergistic effects between C14-surfactin and macrolactin A against methicillin-resistant Staphylococcus aureus (MRSA).

<p>By product that rich in protein such as fish roes are potential as raw material for protein concentrate. This research aimed to utilize skipjack roes to produce protein concentrate and to characterize its functional properties. The method used to extract protein was defatting method using isopropyl alcohol and ethanol with extraction times of 1, 2, and 3 hours.  The results showed that skipjack roes contained 19.81% of protein, 3.41% of fat, 71.32% of moisture, 2.04% of ash, and 1.53% of carbohydrate (by difference). Defatting method using isopropyl alcohol for 3 hours produced the best roe protein concentrate (RPC).  The product meets to the quality requirements of fish protein concentrate type B, contained protein and fat of 71.79% and 2.78%, respectively. This product also had functional properties as follows: water absorption capacity (1.57 ml/g), oil absorption capacity (1.82 g/g), emulsion capacity (81.65%), bulk density (0.51 g/ml), foaming capacity (1.90 ml), foaming stability (0.22 ml) and protein digestibility (95.86%).  Lysine and leucine became the major essential amino acid of RPC, with values were 70.76 and 64.91 mg/g protein, respectively. The composition of amino acids of RPC skipjack consisted of 8 essentials amino acids, 5 non-essentials amino acids and 2 semi-essentials amino acids.</p> <p>Keywords: extraction, fish roe skipjack, roe protein concentrate</p>