Latar Belakang. Gelombang Untrasonik telah digunakan untuk terapi dan diagnosis, di klinik kedokteran gigi popular digunakan untuk ultrasonik skaler. Efek termal dan nontermal gelombang ultrasonik dapat mempengaruhi lingkungan tumbuh bakteri, merusak enzim bakteri, dan struktur bakteri. Streptococcus mutans merupakan bakteri penyebab karies gigi. Tujuan penelitian. Penelitian ini bertujuan untuk mengetahui pengaruh lama paparan gelombang ultrasonik frekuensi terapi 3,5 MHz terhadap jumlah koloni bakteri Streptococcus mutans. Cara penelitian. Penelitian ini dilakukan pada 20 buah cawan petri yang berisi koloni bakteri streptococcus mutans dengan media agar darah. Dua puluh buah petri dibagi menjadi 4 kelompok yaitu kelompok kontrol (A) dan kelompok perlakuan (B, C, D). kelompok perlakuan diaplikasi gelombang ultrasonik frekuensi 3,5MHz  selama 5, 10, dan 15 menit, sedangkan kelompok kontrol tidak diberi perlakuan apapun. Perhitungan jumlah koloni bakteri dilakukan dengan pengamatan menggunakan colony counter dengan standart plate count (SPC) method. Hasil penelitian jumlah koloni bakteri Streptococcus mutans dianalisis menggunakan ANAVA satu jalur menunjukkan ada perbedaan yang signifikan (p<0,05) berarti terdapat pengaruh lama paparan gelombang ultrasonik frekuensi terapi 3,5 MHz terhadap jumlah koloni bakteri Streptococcus mutans. Hasil analisis post hoc (LSD) terhadap jumlah koloni bakteri Streptococcus mutans juga menunjukkan ada perbedaan rerata antar kelompok perlawanan yang signifikan (p<0,05). Kesimpulan. Kesimpulan penelitian ini adalah lama paparan gelombang ultrasonik frekuensi terapi 3,5 MHz berpengaruh terhadap jumlah koloni bakteri Streptococcus mutans.  Introduction. Ultrasonic waves have been used for therapy and diagnosis, in dental clinic ultrasonic waves are used popular for ultrasonic scaler. Thermal and non thermal effects from ultrasonic wave influence the environment of bacteria disturb bacteria enzyme and the bacteria structure. Streptococcus mutans is a bacterium that cause caries in teeth. The aim of this study was to observe the effect of duration of ultrasound in therapy frequency 3,5 MHz exposure towards Streptococcus mutans cell colony. Methods. This study was 20 petri dish with blood agar media containing the Streptococcus mutans cell colony. Twenty plates blood agar, were divided into 4 groups. Control group A was unexposed and treated group received ultrasound exposure at frecuency 3,5 MHz which for 5 minutes exposure (B), 10 minutes exposure (C) and 15 minutes exposure (D). Streptococcus mutans cell colony was countusing colony counter with standard plate count methos. Results. The results of one way ANOVA at 95o/o significance showed that duration ultrasonic therapy frecuency 3,5 MHz exposure influenced the amount of Streptococcus mutans cells colony (p<0,0,5). The post hoc test (LSD) showed the significantly mean difference (p,0,05) between groups. Conclusions. The conclusions, of this study is duration exposure ultrasonic therapy frecuency at 3,5 MHz influences on the amount of Streptococcus mutans cells colony.

The purpose of this research was to investigate the ability of rice endophytic bacteria to synthesize extracellular metabolites before and after gfp (Green Fluorescent Protein) gene transformation. These bacteria were grown in liquid media M63+2mM Tryptophan for 3 days and the supernatants were extracted with absolute methanol 1:1 (v/v). The extractants were then analysed with Gas Chromatography-Mass Spectrophotometry (GC-MS). The GC-MS result showed that all isolates that were tested be it the control (without transformation) and the mutants (transformed) were able to synthesize growth hormones with different composition patterns, namely Indole 3 Butryric Acid (IBA), Indole Acetic Acid (IAA), Kinentin, Cis Zeatin, Zeatin, Benzylaminopurine, Giberellic Acid (GA3, GA1) as well as Zeatin Riboside. Furthermore, the isolates also synthesised osmoprotectants, namely Glycine, Proline, Arabinose, Thiamine, and Trehalose with different composition patterns as well.