Golshan Masoumeh, Dastoorpour Maryam, Kalantary Roshanak Rezaei
Department of Environmental Health Engineering, School of Health, Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
Modeling in Health Research Center, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran.
Water Sci Technol. 2016;74(3):580-5. doi: 10.2166/wst.2016.232.
Pseudomonas facilis and Pseudomonasspp., isolated on the basis of its ability to grow on polycyclic aromatic hydrocarbon, was assayed for biosurfactant production (BP) potentials by measuring the surface tension (ST) of the culture supernatant at different time intervals. The strains in three levels of initial inoculum size (OD600 nm = 0.5, 1, 1.5) were added to medium to determine if bacterial inoculum size affects solubilization of phenanthrene (PHE).The result showed that although the two strains reduced the mean ST to less than 34.12 mN m(-1) at the end of day 6, mean solubilization activity of PHE reached 77.05 mg L(-1) on the sixth day. There was a significant increase in BP over time (P = 0.008); reaching its peak, 157.84 mg L(-1), at the end of the sixth day. Mean solubilization activity of PHE was not significantly different for the two strains (P = 0.216). The time-course study revealed that the ST reduction and BP potential was enhanced as inoculation size increased, leading to higher PHE solubility during the incubation time. However, the trend of increase in PHE solubility was not totally in the same way to cell growth and BP. It may be suggested that more bacterial density needs to be inoculated for practical application of effective bioremediation.
基于其在多环芳烃上生长的能力分离得到的易假单胞菌和假单胞菌属菌株，通过测量不同时间间隔培养上清液的表面张力（ST）来测定其生物表面活性剂产生（BP）潜力。将三种初始接种量水平（OD600 nm = 0.5、1、1.5）的菌株添加到培养基中，以确定细菌接种量是否影响菲（PHE）的溶解。结果表明，尽管这两种菌株在第6天结束时将平均表面张力降低至小于34.12 mN m(-1)，但在第6天菲的平均溶解活性达到77.05 mg L(-1)。生物表面活性剂产生量随时间显著增加（P = 0.008）；在第6天结束时达到峰值157.84 mg L(-1)。这两种菌株的菲平均溶解活性没有显著差异（P = 0.216）。时间进程研究表明，随着接种量增加，表面张力降低和生物表面活性剂产生潜力增强，导致在培养期间菲的溶解度更高。然而，菲溶解度增加的趋势与细胞生长和生物表面活性剂产生并不完全相同。对于有效的生物修复实际应用而言，可能建议接种更多的细菌密度。
