中文摘要：

研究了羧基裂解酶基因对施氏假单胞菌N2降解苯酚的影响。结果表明,施氏假单胞菌N2以唯一碳源苯酚生长时,与野生菌相比,突变菌株的生长明显受到抑制,ubiD和ubiX等羧基裂解酶基因发挥重要作用,并且,就生长特性而言,ubiD基因起关键作用。降解反应期间,对开环产物进行研究发现,基因ubiD主导的是邻苯二酚间位开环,而基因ubiX主导的是邻苯二酚邻位开环。从质谱结果分析,野生菌和突变菌以苯酚为碳源生长时,均能通过羟化和羧化开环裂解途径将苯酚转化成相应的中间产物：顺,顺-己二烯二酸和2-HMS。其中,单突变株N2ubiX-降解苯酚过程中生成的中间产物与野生菌相比,种类相等,但各中间产物含量明显低于野生菌,而单突变株N2ubiD-和双突变菌株N2ubiX-ubiD-代谢苯酚的中间产物的含量及种类都明显低于野生菌。

英文摘要：

The effect of carboxyl cleavage enzyme genes on phenol ring cleavage by Pseudomonas stutzeri N2 was studied.The results showed that,compared with the wild-type N2,the growth of mutant strains was significantly inhibited.The genes ubiD and ubiX play an important role in phenol ring cleavage by N2.Furthermore,the ubiD gene plays a key role in terms of growth characteristics.The ring opening products were studied during phenol degradation.The results showed that the gene ubiD,has an important effect on catechol meta-cleavage,and the gene ubiX has an important effect on ortho-cleavage.The intermediate products were analyzed by mass spectra.Phenol was the only carbon source that could be converted to the corresponding intermediate products by way of the hydroxyl and ring opening.The degradation of phenol by the strain N2ubiX- generated the same kinds of metabolites as the wild-type,but showed less quantities of metabolites than that of the wild-type.The degradation of phenol by the strains N2ubiD- and N2ubiX-uiD- generates fewer metabolites and quantities than that by the wild-type N2.