Aim: This study aimed at optimizing γ-aminobutyric acid (GABA) production using lactic acid bacteria (LAB) of an Indonesian indigenous fermented buffalo milk (dadih) origin. This study utilized LAB previously cultured from dadih that has the ability to produce GABA. Materials and Methods: The study started with the identification of selected LAB by 16S rRNA, followed by optimization of GABA production by culture conditions using different initial pH, temperature, glutamate concentration, incubation time, carbon, and nitrogen sources. 16S rRNA polymerase chain reaction and analysis by phylogenetic were used to identify Lactobacillus plantarum (coded as N5) responsible for the production of GABA. Results: GABA production by high-performance liquid chromatography was highest at pH of 5.5, temperature of 36°C, glutamate concentration of 500 mM, and incubation time of 84 h. Peptone and glucose served as the nitrogen and carbon sources, respectively, whereas GABA was produced at optimum fermentation condition of 211.169 mM. Conclusion: Production of GABA by L. plantarum N5 was influenced by initial pH of 5.5, glutamic acid concentration, nitrogen source, glucose as carbon source, and incubation temperature and time. Keywords: fermented buffalo milk, Indonesian indigenous product, lactic acid bacteria, γ-aminobutyric acid.

Penelitian bertujuan untuk mengisolasi dan mengkarakter khamir potensial pemfermentasi nira aren segar dari dataran rendah dan dataran tinggi di Sumatera Barat. Penelitian menggunakan metode eksperimen yang hasilnya disajikan secara deskriptif. Parameter yang diamati meliputi total mikroba, total khamir, uji potensi isolat khamir melalui uji fermentasi, karakter morfologi isolat khamir potensial pemfermentasi secara in vitro, serta analisis biokimiawi nira aren. Hasil penelitian menunjukkan bahwa keberadaan mikroba alami nira aren tertinggi terdapat pada sampel PAM1 (168 x 104 cfu/ml), total khamir tertinggi terdapat pada sampel HLB (85 x 104 cfu/ml), sedangkan presentase khamir tertinggi terdapat pada sampel HLB (69,1%). Uji potensi isolat melalui uji fermentasi diperoleh 5 isolat yang positifmemfermentasi alkohol. Berdasarkan karakter morfologi isolat-isolat khamir dari beberapa lokasi sampel secara in vitro didapatkan 3 isolat genus Hanseniaspora, 1 isolat genus Schizosaccharomyces, dan 1 isolat genus Saccharomyces.

The purpose of this study is to know the magnitude of the effect of learning Problem Posing on student learning outcomes on the material Linear Equation with One Variable and Linear Inequality with OneVariable in class VII. This research is an experimental research with one group pretest and posttest design. The sample in this research is 26 students of class VII.3. The results of the analysis showed a significant effect of learning Problem Posing on student learning outcomes. This is indicated by the acceptance of alternative hypothesis (H1) on the result of paired samples test with 5% significant level. In addition, there is an increase in the average value of pretest and posttest results of 13.69 from the previous 59.54 to 73.23. Thus it can be said that there is influence of learning model problem posing to the result of learning mathematics of student of class VII in SMPN 1 Batukliang. Suggestions that researchers can convey should be learning Problem Posing can be applied in any appropriate learning, because in addition to improving learning outcomes, students will also get a variety of learning so as to reduce boredom and improve the spirit of students in learning.

Penelitian ini bertujuan untuk mengetahui perbedaan kemampuan berpikir kritis dalam menyelesaikan masalah matematika pada siswa kelas VII SMP Negeri 16 Poleang Tengah ditinjau dari gender. Penelitian ini dilaksanakan di SMP Negeri  16 Poleang Tengah tahun ajaran 2019/2020. Jenis penelitian ini adalah penelitian deskriptif dengan perolehan data menggunakan data kuantitatif dan data kualitatif. Subjek penelitian ini terdiri dari 2 kelas dengan jumlah siswa 40 orang. Teknik analisis data menggunakan analisis deskriptif dan kualitatif yaitu kondensasi data, penyajian data dan penarikan kesimpulan. Hasil penelitian ini adalah siswa laki-laki dengan kemampuan berpikir kritis dalam menyelesaikan masalah matematika diperoleh nilai rata-rata adalah 46,25 sedangkan siswa perempan diperoleh nilai rata-rata sebesar 40,25. Hal ini menunjukkan kemampuan berpikir kritis siswa laki-laki menyelesaikan soal lebih baik dari siswa perempuan. Sedangkan hasil wawancara siswa laki-laki cenderung lebih aktif dalam mengeksplorasi pemahaman yang dimililikinya. Sedangkan siswa perempuan, lebih mengutamakan bagaimana soal terjawab dengan cepat tanpa mengeksplorasi pemahaman yang dimilikinya.

The research about The Effect of Some Alkaloid’s Plant Extract as Activator and the plant media for Acetobacter xylinum (Brown.) Holland in  Fermented of Kombucha Tea, has been done from February to September in STIKes Perintis Laboratory. The aim of this study to know the effects of some alkaloid’s plant extract as activator and the plant media for Acetobacter xylinum (Brown.) Holland in  Fermented of Kombucha Tea. The research used Completely Random Design (CRD) with 6 treatments and 4 replications. The treatments were : black tea, green tea, leaf of coffea, leaf of cocoa, coffea powder and cocoa powder. The result showed that the use of several types of plant extract beralkaloid effect on Kombucha tea products. In this study obtained the average of the highest total bacteria Acetobacter xylinum 117.50 x 107 cfu / ml, the value of pH 3.82, sugar content 9.67. The results of the organoleptic assessment of flavor and taste showed the highest panelist favorites level in Kombucha chocolate powder that is 3.07 (very good) and 3.47 (very good).