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 discovery of novel natural products (NPs) that will serve as lead structures has to be an ongoing effort to fill the respective development pipelines. However, identification of NPs, which possess a potential for application in e.g., the pharma or agro sector, must be as cost effective and fast as possible. Furthermore, the amount of sample available for initial testing is usually very limited, not least because of the fact that the impact on the environment, i.e., the sampled biosystem, should be kept minimal. Here, our pipeline SeaPEPR is described, in which a primary bioactivity screening of crude extracts is combined with the analysis of their metabolic fingerprint. This enabled prioritization of samples for subsequent microfractionation and dereplication of the active compounds early in the workflow. As a case study, 76 marine sponge-derived extracts were screened against a microbial screening panel. Thereunder, human pathogenic bacteria (Escherichia coli ATCC35218 and Staphylococcus aureus ATCC33592) and yeast (Candida albicans FH2173), as well as the phytopathogenic fungus Septoria tritici MUCL45407. Overall, nine extracts revealed activity against at least one test organism. Metabolic fingerprinting enabled assigning four active extracts into one metabolic group; therefore, one representative was selected for subsequent microfractionation. Dereplication of the active fractions showed a new dibrominated aplysinopsin and a hypothetical chromazonarol stereoisomer derivative. Furthermore, inhibitory activity against the common plant pest Septoria tritici was discovered for NPs of marine origin.

Fish balls is a food product that popular and favored by children or adult. Fish balls usually produced as a home industry or commercial product. The aims of this research are to figure out the quality of the home industry or commercial fish ball at Babakan Raya Bogor. This research using a descriptive method. The best score for home industry category, water content analysis for sample A (51.20%), ash analysis for sample A (2.13%), for commercial category, the best fat content is for sample A (0.27%), protein content is for sample A (12.52%) and for carbohydrate by difference is for sample A (18.62%).

Tuna mata besar (Thunnus obesus) merupakan spesies memiliki nilai ekonomis yang tinggi dalam dunia perdagangan. Dalam perspektif fish quality dan safety, tuna dapat menyebabkan permasalahan kesehatan disebabkan adanya kontaminasi mikroorganisme selama proses penangkapan, penanganan maupun pengolahan. Kadar histamin dijadikan indikator mutu dan keamanan pangan produk tuna, karena histamin yang tinggi menyebabkan efek keracunan pada manusia. Penelitian bertujuan menentukan kadar histamin, total bakteri, total Bakteri Pembentuk Histamin (BPH), serta mengidentifikasi bakteri penghasil histamin selama penyimpanan chilling selama sembilan hari. Penelitian dilakukan dalam tiga tahap, yaitu preparasi sampel, penyimpanan sampel, analisis kimia dan mikrobiologi. Selama proses penyimpanan terjadi peningkatan jumlah Total Place Count (TPC), BPH dan kadar histamin secara nyata, baik pada bagian perut, punggung maupun ekor. Jumlah TPC tertinggi terjadi pada hari ke 9 yaitu bagian perut 5,4 x 105 cfu/g, punggung 5,1 x 105 cfu/g, dan ekor 1,0 x 104 cfu/g. Sedangkan jumlah BPH hari ke-9 perut 2,7 x 105 cfu/g, punggung 1,4 x 105 cfu/g, dan ekor 2,3 x 103 cfu/g. Kadar histamin setelah penyimpanan hari ke-9 mengalami peningkatan menjadi 59,73 ppm untuk daging bagian perut, 131,10 ppm daging bagian punggung, dan 96,04 ppm daging bagian ekor. Hasil identifikasi bakteri pembentuk histamin menunjukkan bahwa Bacillus subtilis dengan persentase identifikasi sebesar 99% merupakan bakteri pembentuk histamin pada tuna mata besar.

Kepiting batu (Grapsus albolineatus) merupakan spesies yang banyak ditemukan di pantai berbatu dan eksoskeletonnya adalah salah sumber potensial chitin-chitosan. Chitosan adalah polimer bersifat polikationik dengan chitosan polymer medium (CPM) yang memiliki molekul lebih sederhana sebagai salah satu turunannya. Tujuan penelitian ini adalah untuk menentukan mutu chitosan dan chitosan polymer medium dari cangkang kepiting batu. Metode yang digunakan pada penelitian ini adalah metode eksperimental. Hasil analisis membuktikan bahwa cangkang kepiting memiliki komposisi 4.17±0.08 air, 54.4±2.78 abu, 6.28±0.05 lemak, 23.48±0.01 protein, 11.70±2.93 kaborhidrat. Karakterisasi chitosan memperlihatkan rendemen sebesar 10±0.70%, kadar air 8.10±0.14%, abu 19.39±0.55%, lemak 6.26±0.37%, protein 8.24±0.34%, karbodidrat 50.03±0.04%, derajat putih 60.61±0.86% , viscositas 7.30±0.42 cps dan derajat deasetilasi 55.92±1.30%. Untuk chitosan polymer medium, rendemennya mencapai 98.33±0.40% dan derajat deasetilasinya sebesar 60.22±0.24%. Chitosan dan chitosan polymer medium dari cangkang kepiting batu (Grapsus albolineatus) masih memenuhi standar yang ditetapkan SNI.   Stone crab (Grapsus albolineatus) is a species commonly found in rocky beaches. Its exoskeleton is a good source of chitin and/or chitosan. Chitosan represents a polycationic polymer with chitosan polymer medium (CPM) having simpler molecular formula than chitosan as chitosan’s derivative. The objective of this research was to determine the quality of chitosan and chitosan polymer medium from rock crab’s shells. Experimental method was used in this study with characterization of the crab’s shells showing a composition of 4.17±0.08%, water, 54.4±2.78% ash, 6.28±0.05% fat, 23.48±0.01% protein and 11.70±2.93% carbohydrate. Similar characterization on chitosan revealed a composition of 10±0.70% rendemen, 8.10±0.14% water, 19.39±0.55% ash, 6.26±0.37% fat, 8.24±0.34% protein, 50.03±0.04% charabohydrate, 60.61±0.86% white degree, 7.30±0.42 cps viscosity and 55.92±1.30% degrees of deacetylation. Although chitosan contained similar composition of white degree (60%) and deactylation (60%0 to chitoxan polymer medium, CPM had higher composition of rendemen (98.33±0.40%) than chitosan (10±0.70%). In conclusion, this study shows that chitosan and chitosan polymer medium of G. albolineatus met our national standard (SNI).