Ketut Mahardika
Balai Besar Riset Budidaya Laut dan Penyuluhan Perikanan, Badan Riset dan Sumber Daya Manusia Kelautan dan Perikanan

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EFFECTIVENESS OF A RECOMBINANT VACCINE BASED ON RNA2 CAPSID PROTEIN AGAINST NERVOUS NECROSIS VIRUS IN HYBRID GROUPER Ketut Mahardika; Indah Mastuti; Sudewi Sudewi; Des Roza; Zafran Zafran
Indonesian Aquaculture Journal Vol 15, No 1 (2020): (June, 2020)
Publisher : Center for Fisheries Research, Agency for Marine and Fisheries Research and Human Resource

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15578/iaj.15.1.2020.15-23

Abstract

Nervous Necrosis Virus (NNV) is a devastating viral disease in marine aquaculture, causing significant economic losses worldwide, including in Indonesia. The virus mainly infects larvae and juveniles of marine fishes. This study aimed to determine the effectiveness of a recombinant vaccine from betanodavirus coat proteins expressed in Escherichia coli fish against NNV infection in hybrid grouper. An RNA2 capsid protein was selected and used as the recombinant vaccine. NNV-RNA2 gene was inserted into the protein expression system vector of pET SUMO and cloned in cells of bacteria Escherichia coli strain BL-21. The results of blast homology analysis exhibited that the amino acid sequence of the NNV-RNA2 showed high similarity with Lates calcarifer encephalitis viral coat protein gene. E. coli expressing NNV-RNA2 protein was inactivated using 0.03% formalin and mechanically inactivated by freeze-thaw and sonication methods. The inactivated recombinant E. coli vaccine was then injected intramuscularly into hybrid grouper juveniles (single vaccine). Subsequently, the juveniles were challenged with NNV at 7, 14, and 21 dpv (days post-vaccination). Injection of 0.1 mL sterile PBS served as the control. Single vaccine applications using formalin-inactivated vaccines resulted in higher antibody titers than those of mechanically-inactivated vaccines. Both vaccines were only able to increase antibody titer up to 7 dpv. Therefore, re-vaccination (booster vaccine) was done on day-10 after the first vaccination using a formalin-inactivated vaccine. The booster vaccine could protect hybrid grouper against NNV (P<0.05) at four weeks post-vaccination. However, the mortality of vaccinated and control fish was not significantly different (P>0.05) after challenged with NNV for six weeks after. This recombinant vaccine has the potential to be developed into a polyvalent vaccine by combining viral and other bacterial vaccines in future research.
PERFORMA PERTUMBUHAN DAN NILAI KECERNAAN PAKAN PADA YUWANA KERAPU HIBRID “CANTIK” (Epinephelus fuscoguttatus x Epinephelus polyphekadion) DENGAN PEMBERIAN BAKTERI PROBIOTIK DAN/ATAU ENZIM PAPAIN DALAM PAKAN Muhammad Marzuqi; Haryanti Haryanti; Ni Wayan Widya Astuti; Nyoman Adiasmara Giri; Ketut Mahardika
Media Akuakultur Vol 15, No 1 (2020): (Juni, 2020)
Publisher : Pusat Riset Perikanan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (468.664 KB) | DOI: 10.15578/ma.15.1.2020.29-37

Abstract

Probiotik telah banyak digunakan untuk memperbaiki kualitas lingkungan perairan dalam kegiatan budidaya. Selain itu probiotik juga dapat digunakan dalam pakan ikan. Tujuan penelitian adalah mengetahui efektivitas pemanfaatan probiotik dan enzim papain dalam pakan terhadap pertumbuhan dan nilai kecernaan pakan untuk ikan kerapu hibrid “cantik”. Perlakuan berupa penggunaan probiotik dalam pakan yaitu (pakan A) probiotik dalam pakan, (pakan B) tanpa probiotik dan tanpa enzim dalam pakan (kontrol), (pakan C) enzim dalam pakan dan (pakan D) kombinasi probiotik dan enzim dalam pakan. Hewan uji berupa benih ikan kerapu hibrid dengan ukuran bobot rata rata awal 7,30± 0,60 g. Ikan dipelihara dalam bak polikarbonat bervolume 300 liter yang telah dilengkapi dengan aerasi dan sistem air mengalir dengan kepadatan 50 ekor/bak. Benih ikan diberi pakan percobaan secara satiasi dengan frekuensi pemberian dua kali sehari. Percobaan dirancang dengan rancangan acak lengkap, terdiri atas empat perlakuan pakan dan tiga ulangan. Pengamatan pertumbuhan dilakukan setiap 1 minggu dengan menimbang bobot ikan. Pengamatan meliputi performa pertumbuhan, nilai kecernaan pakan pada ikan kerapu. Hasil penelitian menunjukkan bahwa penggunaan bakteri probiotik pada pakan ikan kerapu berpengaruh terhadap performa pertumbuhan (pertambahan bobot), efisiensi pakan (p<0.05). Pertambahan bobot tertinggi terjadi pada ikan kerapu hibrid yang diberi perlakuan pakan dengan bakteri probiotik (237±0,04%) diikuti pakan dengan enzim (204±0,09%), sedangkan ikan yang diberi pakan dengan kombinasi bakteri probiotik dan enzim diperoleh pertambahan bobot lebih rendah dari pakan kontrol masing masing 118±0,03% dan 192±0,20% dan nilai kecernaan pakan sebesar 79,91-84,24%.Probiotics have been widely used to improve water quality in fish farms. Probiotics are also utilized in fish feed as food supplements. This research was aimed to investigate the efficacy of probiotics and papain enzyme on the growth and nutrient digestibility of hybrid grouper “Cantik”. The experiment was arranged in a Completely Randomized Design consisting of four feed treatments and three replications: diet A, a diet supplemented with probiotic; diet B(control), a diet without supplementation of probiotic and enzyme; diet C, a diet supplemented with enzyme; and diet D, a diet supplemented with probiotic and enzyme. The test fish were hybrid grouper fish fry with an initial average body weight of 7.30 ± 0.60 g. The fish fry were reared in 300 liter volume polycarbonate tanks equipped with aeration and a flowthrough water system at a density of 50 fish/tank. The fish fry were fed with the diets two times a day by satiation for 56 days. The fish growth performance was observed weekly by recording their weight gain, nutrient digestibility, and survival rate. The results showed that the application of probiotic bacteria in the feed had statistically significant effects on the specific growth rate (SGR), weight gain, feed efficiency, and the rate of feed intake (p <0.05). The highest specific growth rate was observed in the fry group treated with the diet containing probiotic ((237±0.04%) followed by the enzyme-supplementing diet (204±0.09%) and the control diet(192±0.20%). The fish group fed with a combination of probiotic and enzyme had the lowest specific growth rate of 118±0.03% and protein digestibility coefficient of 79.91-84.24 %.