Judul: Aspek Biologi Reproduksi Ikan Lemuru (Sardinella longiceps C.V.) di Perairan Teluk Sibolga, Sumatera- Utara
Abstrak: Ikan lemuru (Sardinella longiceps C.V.) merupakan ikan ekonomis penting Saat ini informasi biologis ikan lemuru di perairan Sibolga belum ada. Informasi tersebut dibutuhkan untuk tujuan pengelolaan kegiatan perikanan di wilayah tersebut. Penelitian bertujuan untuk mengetahui aspek biologi reproduksi ikan lemuru (Sardinella longiceps C.V.).
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Judul: Biologi reproduksi Ikan Lemuru (Amblygaster sirm Walbaum,1792) di perairan Selat Sunda
Abstrak: Ikan lemuru (Amblygaster sirm) merupakan bagian dari ikan pelagis kecil yang tertangkap menggunakan purse seine di perairan Selat Sunda, namun belum diketahui dengan memadai aspek biologinya. Tujuan dari penelitian ini yaitu mengkaji beberapa aspek biologi reproduksi yang mencakup rasio kelamin, ukuran pertama kali matang gonad (Lm), musim pemijahan, tipe pemijahan dan potensi reproduksi. Penelitian ini berdasarkan data primer yang dilaksanakan pada bulan April-Agustus 2015 dengan waktu pengambilan contoh dilakukan setiap 30 hari sebanyak lima kali. Jumlah ikan lemuru yang diambil selama penelitian sebanyak 255 ikan betina dan 536 ikan jantan. Hasil penelitian ini menunjukkan bahwa rasio ikan lemuru tidak seimbang (rasio jantan dan betina sebesar 2:1). Hasil analisis ukuran pertama kali matang gonad ikan betina dan jantan masing-masing adalah 186 mm dan 188 mm. Musim pemijahan ikan lemuru terjadi pada bulan Mei sampai Agustus dengan puncak pemijahan pada bulan Juli, dan tipe pemijahan terindikasi bersifat partial spawner. Potensi reproduksi ikan lemuru dapat dikategorikan cukup tinggi dengan kisaran fekunditas 3 600-42 390 butir.
Keyword: reproductive biology, spotted sardinella, Sunda Strait

Judul: Glucose biosensor using a glucose dehydrogenase flavin adenine dinucleotide electrochemically immobilized on zeolite nanoparticles
Abstrak: A glucose biosensor was developed to measure blood glucose levels. The performance of these new glucose biosensors was continuously improved, producing better performance and stability. The technique selection and immobilization matrix are key factors for biosensor development, so that the prospecting of materials that can be used as a matrix for supporting enzyme, continue to be explore. The purpose of this study was to determine the activity and stability of the enzyme glucose dehydrogenase (GDH) that were immobilized on zeolite nanoparticles (NPZ) and determine the kinetic parameters and analytical performance by electrochemical methods. The resulting enzyme electrode with NPZ and enzyme electrode with zeolite A showed a high activity against the enzyme electrode glucose than without NPZ. The reaction kinetics of third electrodes of enzyme followed the Dixon equation. The 𝐼����𝑚����𝑎����𝑥����𝑎����𝑝����𝑝���� values for enzyme electrode without NPZ, with NPZ, and with zeolite A were 27.25 μA, 77.52 μA, and 48.54 μA, respectively. The 𝐾����𝑀����𝑎����𝑝����𝑝���� values for GDH enzyme that immobilized on the NPZ were 1.16 mM, 12.30 mM for GDH enzyme that immobilized on zeolite A and 0.95 mM for GDH enzyme immobilization without NPZ. The enzyme electrode without NPZ, with NPZ, and with zeolite A also showed a high sensitivity with value for the sensitivity were 0.58 μA mM-1, 0.81 μA mM-1, and 2.51 μA mM-1, respectively. The third enzyme electrodes showed different linear area with range for the enzyme electrode without NPZ, with NPZ and with zeolite A were 1.00-15.00 mM, 2.00-20.00 mM, and 0.06-10.00 mM, respectively. The blood glucose level of normal person ranged from 4 to 6 mM, so that the enzyme electrode with NPZ and without NPZ are suitable for use in the determination of the concentration of blood glucose. While the enzyme electrode with zeolite A has a smaller range so it is more suitable to use in the determination of glucose concentration in the foods or beverages. The enzyme electrode with NPZ and the enzyme electrode with zeolite A showed a good accuracy with relative error values were 3.84% and3.48%, respectively. Repeatability measurements also showed a good precission results with relative standard deviation values (%RSD) for the enzyme electrode with NPZ and enzyme electrode with zeolite A were 3.83% and 3.16%, respectively. By combining two immobilization techniques, physical adsorption on zeolite and entrapment on carbon paste, high enzymatic activity, good accuracy, and repeatability was attained. The enzyme electrode with NPZ and the enzyme electrode with zeolite A demonstrated a good electrochemical response toward glucose, allowing it to detect blood glucose levels and glucose levels in foods and beverages.
Keyword: glucose biosensor, immobilization, zeolite