Content Determination For Functional Component Of Ethylparaben By Brevibacillus Brevis FJAT-0809-GLX And It’s Optimization For The Fermentation Conditions

The strain Brevibacillus brevis FJAT-0809-GLX was isolated from soil, which displayed a broad spectrum against pathogenic fungi and bacteria, including Ralstonia solanacearum, Escherichia coli, and Fusarium. Its functional components of ethylparaben was determined with HPLC and the fermentation conditions were optimized.The system was established to test the contents of ethylparaben of this biological strain. Fermented liquid samples was extracted by solid-phase extraction column Oasis HLB, After using chromatographic column of C18. Mobile phase of Methanol and water was in the ratio of 65 to 35, Rate of 1.0 mL/min, detection wavelength of 254 nm, at temperature 25℃ and sample quantity of 10 μL. Linear in the range of 1.0-20.0 mg/L, r=0.998, the recovery was 96.2%-105.3%, RSD was 0.8% on average, with the minimum test was 1.0×10-15(S/N=6). It could be found that this method was simple, rapid, accurate, sensitivity and well repeated and might be used to detect hydroxyl ethyl benzene content in the fermentation.In addition, response surface was used to optimize the fermentation media. Through the single factor screening it could be found that the best carbon source, nitrogen source and metalion were DL-malic acid, peptone, and Na+ respectively. Plackett-Burman design revealed that Bean, DL-malic acid and NaCl in culture media were the three key factors among the eight factors affecting the production significantly. The path of steepest ascent experiment was adopted to estimate the optimal region of the medium composition. Then the optimal combined concentration and mutual effect of the three factors were optimized by response surface methodology(RSM). The result showed that the best medium composition was Bean 25.18 g/L, DL-malic acid 29.68 g/L, NaCl 13.18 g/L, Peptone 2 g/L, temperature 35℃, inoculum 2%, ventilation 100/250 mL, speed 170 rpm. The Optimization results were in good agreement with actual experimental which increased by 71.64% compared with the basic fermentation medium (2.311 mg/mL). This work demonstrated that the method of response surface design analysis could be successfully applied to the culture medium optimization. The optimization of fermentation medium is helpful to understanding of industrial fermentation and also the potential production of ethylparaben.