Babaei Faezeh, Habibi Alireza
Faculty of Petroleum and Chemical Engineering, Razi University, Kermanshah, Iran.
Faculty of Petroleum and Chemical Engineering, Razi University, Kermanshah, Iran,
J Mol Microbiol Biotechnol. 2018;28(5):240-254. doi: 10.1159/000496797. Epub 2019 Mar 8.
In the last decades, biodegradation as an environmentally friendly approach has raised interest in connection with the removal of hydrocarbon pollutants. Its capacity for removing pollutants strongly depends on the type of living cell and environmental conditions. The degradative activity of a new sophorolipid-producing yeast, Candida catenulata KP324968, in the removal of high concentrations of diesel from effluents was statistically evaluated considering the initial pH, the agitation speed, and the initial diesel concentration. The optimal setting of the operational variables at an initial pH of 4.7, an agitation speed of 204 rpm, and an initial diesel concentration of 93.4 g L-1 resulted in the highest total petroleum hydrocarbon removal efficiency: about 82.1% after 6 days (biodegradation rate: 0.378 g gcell-1 h-1). During the cell growth phase, the emulsification index in the medium increased and reached its highest level at 64.6% after 48 h. Further tests indicated that the emulsification capacity was obtained by in situ production of two sophorolipid molecules with an m/z of 533 and 583. In summary, its effective diesel removal and high emulsification capacity makes C. catenulata KP324968 an attractive candidate yeast for the degradation of hydrocarbons from aqueous environments.
在过去几十年中，生物降解作为一种环境友好型方法，在去除烃类污染物方面引起了人们的关注。其去除污染物的能力在很大程度上取决于活细胞的类型和环境条件。考虑到初始pH值、搅拌速度和初始柴油浓度，对一种新的产槐糖脂酵母——链状假丝酵母KP324968在去除废水中高浓度柴油方面的降解活性进行了统计学评估。操作变量的最佳设置为初始pH值4.7、搅拌速度204 rpm和初始柴油浓度93.4 g L-1，这使得总石油烃去除效率最高：6天后约为82.1%（生物降解速率：0.378 g gcell-1 h-1）。在细胞生长阶段，培养基中的乳化指数增加，并在48小时后达到最高水平，为64.6%。进一步测试表明，乳化能力是通过原位产生两种质荷比为533和583的槐糖脂分子获得的。总之，链状假丝酵母KP324968有效的柴油去除能力和高乳化能力使其成为从水环境中降解烃类的有吸引力的候选酵母。
