以原油降解率为目标，考察了5株石油烃降解菌对原油的降解情况，确定铜绿假单胞菌、氧化微杆菌、中间苍白杆菌3株菌接种量以体积比1：1：1混合后，原油降解率最高达74.16%。其中，铜绿假单胞菌、氧化微杆菌对饱和烃均有明显的降解作用，中间苍白杆菌只能够降解部分烷烃。探究了不同盐度对筛选出的3株菌的影响，结果表明，当液体培养基中盐质量浓度从10 g/L上升到50 g/L时，3株菌均能生长，随着含盐质量浓度的增加，菌株浓度依次减少，生长活性减弱，细胞膜通透性变大，细胞失水，导致细胞表面出现褶皱和凹痕，细胞壁变薄，细胞质减少，严重影响了细胞的活性。

Taking the degradation rate of crude oil as target,the degradation of crude oil by five strains of petroleum hydrocarbon-degrading bacteria is investigated.It is determined that the highest degradation rate of crude oil reaches 74.16% when Pseudomonas aeruginosa,Microbacterium oxidans,and Ochrobactrum intermedium are mixed at a ratio of 1:1:1.Among them,both Pseudomonas aeruginosa,and Microbacterium oxidans have obvious degradation effect on all saturated hydrocarbons.Ochrobactrum intermedium can only degrade some alkanes.Subsequently,the effect of different salinity on these three strains of bacteria is investigated.It is shown that all three strains can grow when salt content in the liquid medium increases from 10 g·L^-1 to 50 g·L^-1.As the salinity increases,the bacterial concentration decreases in sequence,the growth activity decreases,the permeability of the cell membrane becomes greater,and the cell loses water,resulting in wrinkles and dents on the cell surface.Cell wall becomes thinner and cytoplasm drops,which affects seriously the activity of the cell.

李彦(1968-),女,硕士,副教授,主要从事油气田环境保护方面的研究,liyan85@xsyu.edu.cn