一株菲高效降解菌的分离鉴定及去除特性

Isolation and identification of an efficient phenanthrene-degrading strain and removal characteristics

从山西省太原市清徐县某焦化厂废水样品中分离筛选得到一株以菲为唯一碳源和能源的高效降解菌株6-1H,经菌体形态观察、生理生化特征和16S rDNA序列同源性分析对其进行了菌种鉴定,并通过环境单因素实验研究了菌株6-1H最佳的生长及菲去除特性,同时对不同菲初始质量浓度的去除过程进行动力学曲线拟合。结果表明,菌株6-1H鉴定为弗留明拜叶林克氏菌(Beijerinckia fluminensis);在初始pH为7.5,温度33℃,盐度(外加NaCl)1.5%的条件下,菌株6-1H在60 h内对菲初始质量浓度为50 mg/L的去除率高达99.3%,OD600为0.21;添加100 mg/L苹果酸或蛋白胨后,培养36 h,菌株生物量(OD600)分别增加至0.27和0.34,菲去除率均达到99%以上,加速菌体生长和菲去除;菌株6-1H对不同浓度菲的去除过程符合一级反应动力学方程,其中菲初始质量浓度为300 mg/L时,菌株6-1H的菲去除速率常数最大且达到0.097 mg/(L·h),其菲去除动力学方程为lnc=-0.097t+6.000,半衰期为7.1 h。

A highly efficient degradation strain 6-1H with phenanthrene as the sole carbon source and energy was isolated and screened from the wastewater discharged from a coking plant in Qingxu County,Taiyuan City,Shanxi Province.The strains were identified by bacterial morphology observation,physiological and biochemical characteristics and 16S rDNA sequence homology analysis,and the optimal growth and phenanthrene removal characteristics of strain 6-1H were studied by environmental single factor experiment.At the same time,the kinetic curve fitting was performed on the removal process of different phenanthrene initial mass concentrations.The results show that strain 6-1H is identified as Beijerinckia fluminensis.Under the conditions of initial pH of 7.5,temperature of 33℃and salinity(plus NaCl)of 1.5%,the removal rate of strain 6-1H to phenanthrene initial concentration of 50 mg/L is 99.3%and OD 600 is 0.21 within 60 h.After adding 100 mg/L malic acid or peptone,the biomass(OD 600)of the strain is increased to 0.27 and 0.34 at 36 h,respectively,and the phenanthrene removal rate is over 99%,which accelerates the growth of bacteria and phenanthrene removal.The phenanthrene removal process of strain 6-1H accords with the first-order reaction kinetics equation.When the initial concentration of phenanthrene is 300 mg/L,the phenanthrene removal rate constant of strain 6-1H is the largest,reaching 0.097 mg/(L·h).Its phenanthrene removal kinetic equation is ln c=-0.097t+6.000,and the half-life is 7.1 h.