Judul: Antibacterial Activity Screening and  Characterization of Potential Bacterial Isolates from Situ Gunung, Sukabumi
Abstrak: Pencarian sumber antibiotik baru diperlukan seiring dengan peningkatan kasus resistensi bakteri patogen terhadap antibiotik. Danau dan curug di Situ Gunung diharapkan dapat menjadi sumber bakteri potensial penghasil senyawa bioaktif. Sebanyak 21 isolat bakteri telah diisolasi dari lingkungan tersebut, tetapi belum dikaji potensinya sebagai penghasil antibakteri. Penelitian ini bertujuan untuk mengarakterisasi dan menganalisis potensi isolat bakteri tersebut sebagai bakteri penghasil antibakteri. Uji antibakteri dengan metode kultur ganda (dual culture) menunjukkan bahwa 3 isolat bakteri (kode: AT 2.12, AT 2.4, AT 1.2) mampu menghambat pertumbuhan Staphylococcus aureus dengan indeks penghambatan yang bervariasi berkisar antara 0,75 - 2,5, namun 21 isolat tersebut tidak dapat menghambat pertumbuhan Escherichia coli. Isolat AT 2.12 memiliki indeks penghambatan terbesar yaitu 2,5. Tiga isolat terpilih memiliki karakter non hemolitik pada media blood agar. Karakterisasi morfologi sel dengan pewarnaan Gram menunjukkan bahwa dua isolat potensial AT 2.12 dan AT 2.4 berturut-turut merupakan Gram negatif dan Gram positif. Kata kunci : antibiotik, bakteri akuatik, Escherichia coli, Situ Gunung, Staphylococcus aureus,, The searching for new antibiotics sources is needed along with the increasing cases of resistance of pathogenic bacteria to antibiotics. Lakes and waterfalls in Situ Gunung are expected to be a potential sources of bacteria producing bioactive compounds. A total of 21 bacterial isolates have been isolated from the environment, but their potential as antibacterial producers has not been studied yet. This study was designed to screen and characterize antibacterial producing bacteria. Antibacterial test using dual culture method showed that 3 bacterial isolates namedly AT 2.12, AT 2.4, AT 1.2 were able to inhibit the growth of Staphylococcus aureus with an inhibitory index that varied between 0.75 - 2.5, but the 21 isolates could not inhibit the growth of Escherichia coli. AT 2.12 isolate showed the largest inhibitory index of 2.5. Three selected isolates had non-hemolytic characters on blood agar medium. Cell morphology characterized by Gram staining showed that two potential isolates coded as AT 2.12 and AT 2.4 were Gram negative and Gram positive group, respectively. Keywords: antibiotic, aquatic bacteria, Escherichia coli, Situ Gunung, Staphylococcus aureus
Keyword: antibiotik, bakteri akuatik, Escherichia coli, Situ Gunung, Staphylococcus aureus

Judul: Biodiversitas dan karakterisasi senyawa antibakteri dari streptomyces sp.
Abstrak: Antibiotik adalah senyawa yang dihasilkan oleh mikroorganisme yang dapat membunuh atau menghambat pertumbuhan mikroorganisme lainnya. Berbagai antibiotik telah banyak digunakan dalam dunia kesehatan untuk melawan infeksi bakteri. Masalah yang timbul kemudian adalah munculnya galur- galur bakteri patogen yang resisten terhadap antibiotik tersebut. Beberapa galur Stapylococcus aureus dan Escherichia coli yang merupakan bakteri patogen pada saluran pernafasan dan pencernaan manusia ternyata multiresisten terhadap berbagai antibiotik. Streptomyces adalah salah satu mikroorganisme yang memiliki potensi menghasilkan senyawa antibakteri. Karena itu diperlukan penelitian-penelitian untuk mencari biakan-biakan unggul Streptomyces yang dapat melawan infeksi S. aureus dan E.coli. Penelitian ini bertujuan mempelajari biodiversitas Streptomyces asal Indonesia, melakukan penapisan isolat senyawa antibakteri yang berpotensi unggul menghambat pertumbuhan Enteropatogenic Escherichia coli (EPEC) dan S. aureus resisten ampisilin, dan menguji stabilitas ekstrak terhadap pH dan suhu. Isolat-isolat Streptomyces yang digunakan dalam penelitian ini memperlihatkan karakteristik warna yang berbeda-beda. Dari 117 isolat Streptomyces, 22 isolat (18,8%) menghambat EPEC D 15.10, 5 isolat (4,3%) menghambat S. aureus resisten ampisilin, dan 22 isolat (18,8%) menghambat keduanya. Ekstrak dari isolat 42-B-12 paling potensial untuk dikembangkan sebagai antibiotik karena masih memperlihatkan aktivitas hambatan cukup kuat terhadap EPEC dan S. aureus setelah mengalami pemanasan sampai suhu 121°C ( zona jernih 2,3-3 mm) dan stabil pada kondisi asam ( 4,5-6,5 mm).
Keyword: antibiotik

Judul: Application of Mel Frequency Cepstrum Coefficients (MFCC) as Feature Extraction on Phoneme Recognition with Probabilistic Neural Network (PNN) as Classifier
Abstrak: Voice recognition (speech recognition) is one field of study in voice processing. This technology can convert voice signals into a form of written information (text). With this technology, people can interact with a computer. MFCC feature extraction computes the cepstral coefficients by considering the human hearing. This research is a phoneme recognition using feature extraction MFCC and PNN as feature matching model. This study compares the coefficient, overlap, and the test data without noise and with noise. MFCC is used with 13, 20, 26 coefficients and 0%, 25%, 50% overlap. Noise is added by 30 dB, 20 dB and 10 dB. From the comparison of the three overlaps, produced the best accuracy at 50% overlap with an accuracy of 94,71%. From comparing the three coefficients, better accuracy resulting in coefficients of 20 and 26 with an accuracy of 97,12% at 50% overlap. After comparing between the coefficients of 20 and 26 with overlap of 25% then the coefficient 26 is obtained that better accuracy of 94,23%. This shows that in this study the coefficient 26 is the best. In this research, there are three noise variables. The variables are 10 dB, 20 dB, and 30 dB. The best accuracy reached when the noise variable is 30 dB rather than 10 dB or 20 dB because the accuracy has the closest accuracy compared by the accuracy when noise was not added into the data. When the noise variable is 30 dB, the percentage of accuracy is 85,3%.
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