混合烷烃对野油菜黄单胞菌合成黄原胶的影响

本实验研究野油菜黄单胞菌以玉米淀粉作为碳源进行黄原胶生物合成过程中,添加作为携氧剂的混合烷烃对提高产胶率的影响,同时电镜观察不同发酵时期野油菜黄单胞菌的产胶情况。在摇瓶发酵的基础上,进行发酵罐实验。添加8%混合烷烃发酵66h后,黄原胶产胶率和碳源转化率明显提高。结果显示:摇瓶发酵产胶率可达3.84%(对照组为2.58%),碳源转化率为76.8%(对照组为51.6%);发酵罐产胶率可达4.18%(对照组为2.90%),碳源转化率为83.6%(对照组为58.0%)。

Effects of Oxygen-vectors(Alkane Mixture)on Xanthan Gum Biosynthesis in Cultures of Xanthomonas campestris

Xanthan gum is categorized to be an exospore heteropolysaccharide in cultures of Xanthomonas campestris during fermentation in carbohydrates (corn starch) as main substrate. In order to improve xanthan gum productivity, the effects of adding oxygen-vectors (alkane mixture) on xanthan fermentation were studied. Also, the strains were observed at different fermentation time under transmission electron microscope (TEM). When cultivated for 66 h by addition of 8% alkane mixture, xanthan gum yield and transformation rate of carbon source were obviously increased. By means of the shaking flask testing the results were 3.84% and 76.8% for the gum productivity and transformation rate respectively (control, 2.58% and 51.6%, respectively), whereas in the fermentor testing those were 4.18% and 83.6% respectively (control, 2.90% and 58.0%, respectively).