This study reports the analysis of biosurfactant production by a bacterial consortium culture (CC) during biodegradation of crude oil. The ability of CC (5% v/v), grown in Minimal Medium (MM) added with 1% (v/v) Tapis crude oil, to produce biosurfactant under different incubation times (0, 2, 4, 6 and 8 week) was investigated. Biosurfactant activity was estimated by water surface tension changes and emulsification index (E24). Maximum biosurfactant production was observed at 2 weeks incubation period, after which the yield gradually decreased. The biosurfactant produced by the CC significantly decreased the surface tension of water from 72 dynes/cm to 52 dynes/cm (p < 0.05) at week 4. Emulsification test indicated that this biosurfactant effectively emulsified the crude oil with an emulsification index (E24) of 85% (p < 0.05). This is significantly better (p < 0.05) when compared to other chemical surfactants tested namely SDS (53.3%), Tween-20 (50.8%) and Triton X-100 (55%). These results indicate the capability of CC to produce biosurfactant during crude oil degradation and this can be exploited for enhanced bioremediation in oil contaminated areas.

Penelitian ini bertujuan untuk mengidentifikasi bagaimana pelaksanaan pengelolaan kelas dalam pembelajaran tematik yang berbasis google classroom. Penelitian ini menggunakan pendekatan kualitatif deskriptif dengan metode daring. Penelitian ini dilakukan pada semester ganjil siswa kelas III SD Swasta Al-Ulum Medan. Sumber data dalam penelitian ini yaitu guru, materi pembelajaran tematik serta RPP. Teknik pengumpulan data adalah dengan menggunakan observasi, dokumentasi serta wawancara. Sedangkan hasil dari penelitian ini adalah pembelajaran tematik dengan menggunakan penggunaan aplikasi google classroom terbukti sangat efektif digunakan bagi guru dan siswa kelas III SD dengan sistem daring. Pembelajaran tematik dengan pemanfaatan aplikasi google classroom dilaksanakan dengan memisah-misahkan mata pelajaran.

The purpose of this reserach was to find out the effect of quantum model to students learning independence for elementary school in teaching natural science learning. The research design was classroom action research. This research was done at SDN 060827 Medan with the subject of the research was 37 students of grade V. The data collection was using: observation and questionnaire.  The data was described and elaborated by mixing some steps, they were collecting the data  data reduction, data display and finally conclusion. The result of the research prove that there was effect of quantum model to students’ learning independence for elementary school  in teaching natural science learning. Among of indicators, the highest score was motivation. Quantum model is very effective to use in teaching natural science learning for elementary school