Nasr Shaghayegh, Soudi Mohammad Reza, Haghighi Manouchehr
Department of Microbiology, Faculty of Science, Alzahra University, Tehran, Islamic Republic of Iran.
Pak J Biol Sci. 2007 Sep 1;10(17):3010-3. doi: 10.3923/pjbs.2007.3010.3013.
In this study, we used a native strain of X. campestris for xanthan production in lab-scale fermentor and the product was recovered with organic solvents and dried. Then we studied the potential usage of our products in different harsh conditions, including heat, pH and salinity treatments. Furthermore, we used 2D-micromodel for microbial oil recovery investigations. According to present experiments, temperature and salt contents did not have a significant influence on rheological behavior of xanthan solutions and these aqueous solutions maintained at least 80% of their primary viscosity. In addition, these solutions were resistant to a broad range of pH variations. Viscosity of the xanthan solution was increased as it was heated over 120 degrees C. Micro-model experiments showed that the most efficient concentration of xanthan for Enhanced Oil Recovery (EOR) is 1000 mg L(-1) and 53% of original oil in place was recovered, which showed remarkable increase comparing to original oil in place that was recovered (31%) from sole water flooding. The same or even better results were obtained from native xanthan, when its properties were compared to those of a commercial sample which was gifted by NIOC.
在本研究中，我们使用野油菜黄单胞菌的一个本地菌株在实验室规模的发酵罐中生产黄原胶，并用有机溶剂回收产物并干燥。然后我们研究了我们的产品在不同苛刻条件下的潜在用途，包括热、pH值和盐度处理。此外，我们使用二维微观模型进行微生物采油研究。根据目前的实验，温度和盐含量对黄原胶溶液的流变行为没有显著影响，这些水溶液至少保持其初始粘度的80%。此外，这些溶液能抵抗广泛的pH值变化。当黄原胶溶液加热到120摄氏度以上时，其粘度会增加。微观模型实验表明，用于提高采收率（EOR）的黄原胶最有效浓度为1000 mg L(-1)，原地原油采收率为53%，与通过单纯水驱采收的原地原油（31%）相比有显著提高。当将天然黄原胶的性能与由伊朗国家石油公司赠送的商业样品的性能进行比较时，得到了相同甚至更好的结果。
