2种假单胞菌对乌海风化煤的连续降解

Sequential degradations of weathered coal in Wuhai by two types of pseudomonas

为提高煤的微生物降解率,实现煤的微生物法产业化应用,进行了2种假单胞菌(日本假单胞菌和铜绿假单胞菌)对内蒙古乌海风化煤的微生物连续降解研究。首先,采用了3种组合降解模式和2种单一降解模式对煤样进行生物转化,降解结束后使用重量法和紫外可见吸光度法评估各个降解路线的生物降解率,并分别对不同降解路线的产物进行表征;然后,选最优工艺路线进行微生物降解,用紫外可见光吸光度、红外光谱和GC-MS等表征分析了降解过程中煤的官能团变化和液相产物的组成和结构;最后,在此基础上,探究了内蒙古乌海氧化风化煤微生物转化的连续降解机制。结果表明:先用日本假单胞菌,再利用铜绿假单胞菌进行连续降解(表示为“日本假单胞菌→铜绿假单胞菌”)为最优降解路线,降解率由单一菌种的49.2%提高到了68.2%;在乌海氧化风化煤的微生物降解过程中,日本假单胞菌更容易降解煤的脂肪族侧链,而芳香族骨架则更容易被铜绿假单胞菌降解;最优降解顺序“日本假单胞菌→铜绿假单胞菌”降解乌海氧化风化煤的可能过程为先降解煤表面的长链烷烃,再降解煤内部的芳香烃。研究结果对提高煤的微生物降解率和实现煤的微生物转化利用具有一定的指导意义。

In order to improve the microbial degradation rate of coal and achieve the industrial application of the coal microbial method,two types of pseudomonas(Pseudomonas Japonica and Pseudomonas Aeruginosa)were studied for sequential microbial degradation of weathered coal from Wuhai,Inner Mongolia.Three combined degradation modes and two single degradation modes were used to biotransform coal samples.After degradation,each degradation route were evaluated using gravimetric and UV-vis absorbance methods,and the products of different degradation routes were characterized separately.The optimal process was selected for microbial degradation,and the changes of functional groups of coal and the composition and structure of liquid products in the process of degradation were characterized by UV-vis,IR and GC-MS.The sequential degradation mechanism of microbial transformation of weathered coal in Wuhai,Inner Mongolia was explored accordingly.The results showed that using Pseudomonas Japonica first and then using Pseudomonas Aeruginosa for sequential degradation(represented as“Pseudomonas Japonica→Pseudomonas Aeruginosa”)was the optimal degradation route,and the degradation rate increased from 49.2%of a single strain to 68.2%.In the microbial degradation process of weathered coal in Wuhai,Pseudomonas Japonica is more likely to degrade the aliphatic side chains of coal,while the aromatic skeleton is more easily degraded by Pseudomonas Aeruginosa.The optimal degradation sequence“Pseudomonas Japonica→Pseudomonas Aeruginosa”may involve the degradation of long-chain alkanes on the surface of Wuhai weathered coal,followed by the degradation of aromatic hydrocarbons inside the coal.The results are instructive for improving the microbial degradation rate of coal and realising the microbial conversion and utilisation of coal.