Judul: Analysis of The Dominant Bacteria in Raw Beef During Refrigerated Storage Using 16S rRNA Sequencing
Abstrak: Daging sapi merupakan salah satu produk hewani yang bernilai gizi tinggi dan sering disimpan pada suhu rendah (refrigerator). Proses penyimpanan daging dapat memicu tumbuhnya berbagai bakteri, termasuk bakteri patogen pembusuk. Sebagian besar penelitian yang menganalisis profil bakteri pada daging selama penyimpanan dilakukan dengan menggunakan metode konvensional. Sehingga pendekatan metagenomik 16S rRNA dianggap dapat digunakan untuk untuk menganalisis bakteri yang tidak dapat dibudidayakan. Penelitian ini bertujuan untuk mengidentifikasi bakteri dominan pada daging sapi mentah selama penyimpanan refrigerator menggunakan 16S rRNA sekuensing. Sampel daging sapi bagian lamusir disimpan pada refrigerator dengan waktu penyimpanan 0, 3 dan 7 hari. Total DNA genom bakteri kemudian diekstraksi dan digunakan sebagai template untuk amplifikasi menggunakan primer 9F dan 1541R. Produk PCR lalu diurutkan dan dianalisis menggunakan BLAST-N. Sebagai data pendukung, nilai pH sampel juga diukur. Hasil penelitian menunjukkan bahwa sekuens 16S rRNA bakteri yang dominan pada daging mentah D0 adalah Macrococcus sp.. Sedangkan bakteri yang dominan pada penyimpanan D3 dan D7 adalah Acinetobacter sp.. Nilai pH daging tidak berbeda nyata selama masa penyimpanan.
Keyword: 16S rRNA, bacteria, beef, sequencing

Judul: Analysis of Dominant Bacteria in Cow's Milk During Storage at Refrigerator Temperature Using 16S rRNA Sequencing
Abstrak: Susu sapi selain sebagai sumber nutrisi yang baik untuk dikonsumsi, juga merupakan media yang sesuai untuk pertumbuhan bakteri. Kajian mengenai profil bakteri di dalam susu erat kaitannya dengan kualitas mikrobiologi susu sapi, tetapi terbatas pada profil bakteri yang bisa dikulturkan (cultivable) saja. Pendekatan molekuler identifikasi menggunakan 16S rRNA saat ini memungkinkan untuk mengidentifikasi bakteri pada susu tanpa proses kultivasi. Penelitian ini bertujuan untuk menganalisis dominan bakteri yang ada pada susu sapi selama penyimpanan pada suhu refrigerator dengan menggunakan metode 16S rRNA sekuensing. Hasil penelitian menunjukkan bahwa pH sampel susu sapi berkisar antara 6,47–6,67. Konsentrasi dan kemurnian total DNA bakteri cenderung fluktuatif pada setiap sampel. Total DNA genomik kemudian diekstraksi dan digunakan sebagai template amplifikasi gen 16S rRNA menggunakan primer 9F dan 1541R. Hasil analisis sekuens 16S rRNA menunjukkan bahwa bakteri dominan sampel susu sapi S0 adalah Bifidobacterium sp., bakteri dominan sampel susu sapi S3 adalah Acinetobacter sp., dan bakteri dominan sampel susu sapi S7 adalah Enterococcus sp.., Apart from being a good source of nutrition for consumption, cow's milk is also a suitable medium for bacterial growth. The study of the bacterial profile in milk is closely related to the microbiological quality of cow's milk but is limited to the profile of cultivable bacteria only. Molecular identification approaches using 16S rRNA currently allow the identification of bacteria in milk without a cultivation process. This research aims to analyze the dominant bacteria in cow's milk during storage at refrigerator temperature using the 16S rRNA sequencing method. The research results showed that the pH of cow's milk samples ranged from 6,47–6,67. The concentration and purity of total bacterial DNA tend to fluctuate in each sample. Total genomic DNA was then extracted and used as a template for 16S rRNA gene amplification using primers 9F and 1541R. The results of 16S rRNA sequence analysis showed that the dominant bacteria in cow's milk sample S0 was Bifidobacterium sp., the dominant bacteria in cow's milk sample S3 was Acinetobacter sp., and the dominant bacteria in cow's milk sample S7 was Enterococcus sp..
Keyword: 16S rRNA, bacteria, cow's milk, sequencing

Judul: Hybrid solar cells of ZnO nanoparticles/chlorophyll was modified metal ions (Zn2+ and Cu2+ )
Abstrak: Zinc Oxide (ZnO) is a n-type semiconductor with a wide the energy band (Band Gap) is 3.37 eV at room temperature and 3.34 eV at low temperature with a large exiton binding energy is 60 meV. ZnO has been synthesized by hydrothermal method, resulting in a decrease in particle size over the duration of the hydrothermal changes. Crystallographic structure of ZnO were characterized using XRD, has shown the characteristic pattern of a hexagonal wurtzite structure, the crystallite size increases to changes in particle size. Changes in particle size has also led to a change in the absorption peak of ZnO as has been demonstrated posted under test using the optical properties of UV-Vis spectrophotometer. Changes of this uptake has also led to changes in the energy band gap, which increases its band gap energy of the particle size. In electronic applications, especially in solar cells. Chlorophyll is considered less effective, because of their very nature are easily degraded as a result of several reactions which are acid, lighting and temperature. The results of the stability test using a halogen lamp 34 W/m2 for 5 hours, that the substitution of chlorophyll with metal ions Zn2+ and Cu2+ has been shown to form more stable than natural chlorophyll. The characterization of the optical properties, the combination of ZnO / chlorophyll in the form of hybrid films has led to a shift in the absorption region of ZnO becomes more widely from the UV to Visible. ZnO/chlorophyll has absorption range of 350-515 nm, ZnO / Zn-feofitin 332-401 nm and 332-632 nm for Cu-feofitin. The combination of ZnO/chlorophyll and CuSCN as a solid electrolite in hybrid solar cell, a modified chlorophyll with metal ions Zn2+ and Cu2+ has been shown to form a more stable I-V curve. It is characterized by its fill factor value greater than natural chlorophyll. Nevertheless, solar cells with natural chlorophyll has been able to produce higher efficiency values of chlorophyll were substituted.
Keyword: Hydrothermal, ZnO/Chlorophyll modified, Hybrid Solar Cell