| Summary: | 碩士 === 國立高雄海洋科技大學 === 海洋生物技術研究所 === 100 === Brevibacillus brevis R15 was isolated from the kitchen waste composting and found high emulsifying activity. The surfactant-like compound was purified in this study. The chemical structure of the surfactant-like compound was studied by means of electrospray ionization mass spectrometry (ESI-MS), NMR, HPLC and Fourier transform infrared spectroscopy (FTIR). As the results, the surfactant-like compound produced from Brevibacillus brevis R15 was considered to be polyols. As far as we know, the surfactant-like compound produced by B. brevis R15 is a new type of biosurfactant. The surfactant-like compound exhibited a good surface activity of 41.4 mN/m. The emulsion volume (EV%) was 71.4% to kerosene. The melting point of the compound was 98.5oC. The rotation of polarization to the compound was dextrorotatory, 〖[α]〗_D^28=+〖18.0770〗^o. The surfactant-like compound was capable of emulsifying kerosene in a broad pH range (5-9), temperature (30-121oC) and in the presence of NaCl up to 12% (w/v). The compound produced from B. brevis R15 was stable in a solution containing 0 to 1,000 ppm of MgCl2 and CaCl2. The surfactant-like compound was thermostable and also stable in broad range of pH. The emulsifying activity of this compound was functioned in a board range of NaCl concentration. Based on the results, the surfactant-like compound from B. brevis R15 could be useful in environmental application, petroleum industry, and cosmetics applications potentials.
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