Ghribi Dhouha, Ellouze-Chaabouni Semia
Départment de Biotechnolgie, Institut Supérieur de Biotechnologie de Sfax, B.P. 261, Sfax 3038, Tunisia.
Biotechnol Res Int. 2011;2011:653654. doi: 10.4061/2011/653654. Epub 2011 Sep 27.
Interest in biosurfactants has increased considerably in recent years, as they are potentially used in many commercial applications in petroleum, pharmaceuticals, biomedical, and food processing industries. Since improvement of their production was of great importance to reduce the final coast, cultural conditions were analyzed to optimize biosurfactants production from Bacillus subtilis SPB1 strain. A high yield of biosurfactants was obtained from a culture of B. subtilis using carbohydrate substrate as a carbon source; among carbohydrates, glucose enhanced the best surfactin production. The optimum glucose concentration was 40 g/L. Higher amount of biosurfactants was obtained using 5 g/L of urea as organic nitrogen source and applying C/N ratio of 7 with ammonium chloride as inorganic nitrogen source. The highest amount of biosurfactants was recorded with the addition of 2% kerosene. Moreover, it was shown, using an automated full-controlled 2.6 L fermenter, that aeration of the medium, which affected strongly the growth regulated biosurfactants synthesis by the producing cell. So that, low or high aerations lead to a decrease of biosurfactants synthesis yields. It was found that when using dissolved oxygen saturation of the medium at 30%, biosurfactants production reached 4.92 g/L.
近年来，人们对生物表面活性剂的兴趣大幅增加，因为它们有可能用于石油、制药、生物医学和食品加工行业的许多商业应用中。由于提高其产量对于降低最终成本至关重要，因此对培养条件进行了分析，以优化枯草芽孢杆菌SPB1菌株生产生物表面活性剂的工艺。以碳水化合物底物作为碳源，从枯草芽孢杆菌培养物中获得了高产的生物表面活性剂；在碳水化合物中，葡萄糖能最好地促进表面活性素的产生。最佳葡萄糖浓度为40 g/L。以5 g/L尿素作为有机氮源，氯化铵作为无机氮源，碳氮比为7时，可获得更高产量的生物表面活性剂。添加2%煤油时，生物表面活性剂的产量最高。此外，使用自动全控2.6 L发酵罐的实验表明，培养基的通气对生产细胞生长调节的生物表面活性剂合成有强烈影响。因此，低通气或高通气都会导致生物表面活性剂合成产量下降。研究发现，当培养基的溶解氧饱和度为30%时，生物表面活性剂产量达到4.92 g/L。
