二苯并噻吩降解菌的筛选鉴定及煤脱硫的研究

Study on screening and identification of dibenzothiophene-degrading strain and its application to coal desulfurization

从某石油化工厂的气浮池附近的土壤中,分离得到1株能降解二苯并噻吩的菌株DBZT,经菌株的形态特征、生理生化指标和16S rDNA序列分析,鉴定属于苍白杆菌属(Ochrobactrum sp.)。GC-MS分析菌株的发酵液,表明该菌株能将二苯并噻吩还原生成联苯。应用正交实验的方法研究了苍白杆菌DBZT在煤炭脱硫过程中煤粒度、菌液接种量和浸滤时间3个因素的组合对其脱硫效果的影响,并筛选出各因素的最佳实验条件。实验结果表明,浸滤时间对煤脱硫效率的影响最为显著。在浸滤时间为24 h,煤粒度小于0.094 mm,接种的细菌数量为3×106cfu/g煤样的条件下,菌株DBZT脱去全硫的效果最佳,达到16.28%。

A strain DBZT,which could desulfurize dibenzothiophene（DBT）,was screened from the soil sample collected from the neighboring site of floatation tank of a petrochemical works.This strain was identified as Ochrobactrum sp.according to its morphological,physiological and biochemical characteristics,and 16S rDNA sequence.The gas chromatography-mass spectrometry analysis of ferment proved that the bacterium could convert DBT to biphenyl.The influence of coal granularity,inoculation amount of bacteria and lixiviating time to desulfurization rates was studied and the optimum conditions for various factors were sieved by orthogonal test method.The results showed that in the range of the factor levels studied,lixiviating time made the most significant influence on the desulfurization rates.The test conditions were optimum which lixiviating time was 24 hour,inoculation amount of bacteria was 3×106 cells per gram of coal and coal particle size was less than 0.094 mm.The desulfurization rate of total sulfur reached 16.28% under these optimized conditions.