Authors:Ni Wayan Desi Bintari, Putu Ayu Parwati Pages: 1 - 12 Abstract: Abstract: The tropics have significant future challenges in controlling the vectors of dengue hemorrhagic fever. The occurrence of resistance to chemical control encourages the development of strategies based on biological control. This study aimed to test the larvicidal activity of Streptomyces sp. liquid culture toward A. aegypti larvae. The selection of Streptomyces as a bio-larvicide was carried out by a chitinase test. Chitinase-producing bacteria were cultivated in biomass culture. The study was conducted using a completely randomized design. The results of this study can be isolated 4 Streptomyces isolates from muddy soil. Among the isolates, Streptomyces sp.4 showed chitinolytic activity on in vitro tests; therefore, it was used for larvicidal activity. Based on the Duncan test result, Streptomyces sp.4 culture showed a significant effect on larval mortality compared to the negative control (p<0.05). The highest rate of larval mortality was found in the A6B1 treatment (34.35%). The results of the Probit test showed that the LD50 value of the Streptomyces sp.4 culture was 24.6±5.4 mL. Based on the in vivo test, showed that Streptomyces sp.4 liquid culture affected the mortality rate of A. aegypti larvae and was significantly different from the negative control (p<0.05). Streptomyces sp.4 is known to have potential benefits as a biological larvicidal agent.Abstrak: Daerah tropis memiliki tantangan besar kedepannya dalam pengendalian vektor demam berdarah dengue (DBD). Adanya kejadian resistensi pengendalian dengan zat kimiawi mendorong strategi pengembangan berbasis pengendalian biologis. Penelitian ini bertujuan untuk melakukan pengujian aktivitas kultur Streptomyces sp. sebagai larvasida A. aegypti. Seleksi Streptomyces sebagai biolarvasida dilakukan dengan uji aktivitas kitinase. Bakteri penghasil kitinase dilakukan kultivasi kultur biomassa untuk pengujian in vivo. Rancangan uji menggunakan Rancangan Acak Lengkap. Hasil penelitian dapat diisolasi 4 isolat Streptomyces yang diisolasi dari tanah berlumpur. Diantara keempat isolat, satu isolat yaitu Streptomyces sp.4 menunjukkan aktivitas kitinolitik sehingga digunakan untuk uji aktivitas larvasida secara in vivo. Hasil uji larvasida menunjukkan perlakuan kultur Streptomyces sp.4 berpengaruh nyata terhadap persentase kematian larva dibandingkan kontrol negatif (p<0.05) berdasarkan hasil uji Duncan. Persentase kematian tertinggi didapatkan pada perlakuan A6B1 yaitu sebesar 34.35%. Hasil uji Probit menunjukkan nilai LD50 dari kultur Streptomyces sp.4 adalah 24.6 ± 5.4 mL. Berdasarkan hasil uji in vivo diketahui bahwa perlakuan kultur cair Streptomyces sp.4 berpengaruh terhadap tingkat kematian larva A. aegypti dan berbeda nyata dengan kontrol negative (p<0.05). Streptomyces sp. 4 diketahui memiliki potensi sebagai salah satu agen larvasida biologis. PubDate: 2023-01-18 DOI: 10.22373/ekw.v8i2.11436 Issue No:Vol. 8, No. 2 (2023)
Authors:Muhammad Abimansyah Saragih, Muhammad Irvan Hasibuan, Loren Simangunsong, Ahmad Nasir Pulungan, Junifa Layla Sihombing Pages: 13 - 25 Abstract: Abstract: The need for energy continues to increase along with rapid population growth. Fuel is one of the most critical energy sectors. However, the limited availability of fossil fuels and the issue of air pollution have prompted various studies to find alternative fuels that are renewable and environmentally friendly. In this study, the conversion of castor oil into biohydrocarbons through the hydrodeoxygenation (HDO) process using the HZSM-5 catalyst loaded with Ni (Ni/HZSM-5) aims to produce biohydrocarbon products as a component of liquid fuel. This research has been carried out in 3 main stages, including: 1) Catalyst preparation; 2) Catalyst characterization; and 3) Activity and selectivity test of HZSM-5 catalyst and Ni/HZSM-5 in the hydrodeoxygenation process of castor oil at reaction temperatures of 350 oC, 375 oC, and 400 oC. The conversion results of castor oil using HZSM-5 and Ni/HZSM-5 catalysts were 3.23%, 25.65%, 43.72%, and 13.78%, 35.03%, 71.01%, respectively. From the GC-MS analysis data on the product at 400 oC, the selectivity of HZSM-5 and Ni/HZSM-5 was 20.02% and 23.71% for the kerosene fraction, as well as 15.79% and 11.01% for the gasoil fraction, respectively.Abstrak: Kebutuhan energi terus meningkat seiring dengan pertumbuhan jumlah penduduk yang sangat pesat. Salah satu sektor energi yang paling dibutuhkan adalah bahan bakar minyak. Namun kesediaan bahan bakar fosil yang terbatas dan isu pencemaran polusi udara, mendorong berbagai penelitian untuk menemukan alternatif bahan bakar yang terbarukan dan ramah lingkungan. Dalam penelitian ini, konversi minyak jarak menjadi biohidrokarbon melalui proses hidrodeoksigenasi (HDO) menggunakan katalis HZSM-5 teremban logam Ni (Ni/HZSM-5) bertujuan untuk menghasilkan produk biohidrokarbon sebagai komponen bahan bakar cair. Penelitian ini telah dilakukan dengan 3 tahapan utama yaitu 1) Preparasi katalis, 2) Karakterisasi katalis, 3) Uji aktivitas dan selektifitas katalis HZSM-5 serta Ni/HZSM-5 dalam proses hidrodeoksigenasi minyak biji jarak dengan temperatur proses 350 oC, 375 oC, dan 400 oC. Hasil konversi minyak biji jarak dengan menggunakan katalis HZSM-5 dan katalis Ni/HZSM-5 berturut-turut sebesar 3.23%, 25.65%, 43.72% dan 13.78%, 35.03%, 71.01%. Dari data analisis GC-MS produk di suhu 400 oC diperoleh selektivitas katalis HZSM-5 dan katalis Ni/HZSM-5 berturut-turut adalah 20.02% dan 23.71% untuk fraksi kerosene, serta 15.79% dan 11.01% untuk fraksi gasoil. PubDate: 2023-01-18 DOI: 10.22373/ekw.v8i2.12583 Issue No:Vol. 8, No. 2 (2023)
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