Vila J, López Z, Sabaté J, Minguillón C, Solanas A M, Grifoll M
Department of Microbiology, University of Barcelona, Barcelona, Spain.
Appl Environ Microbiol. 2001 Dec;67(12):5497-505. doi: 10.1128/AEM.67.12.5497-5505.2001.
Mycobacterium sp. strain AP1 grew with pyrene as a sole source of carbon and energy. The identification of metabolites accumulating during growth suggests that this strain initiates its attack on pyrene by either monooxygenation or dioxygenation at its C-4, C-5 positions to give trans- or cis-4,5-dihydroxy-4,5-dihydropyrene, respectively. Dehydrogenation of the latter, ortho cleavage of the resulting diol to form phenanthrene 4,5-dicarboxylic acid, and subsequent decarboxylation to phenanthrene 4-carboxylic acid lead to degradation of the phenanthrene 4-carboxylic acid via phthalate. A novel metabolite identified as 6,6'-dihydroxy-2,2'-biphenyl dicarboxylic acid demonstrates a new branch in the pathway that involves the cleavage of both central rings of pyrene. In addition to pyrene, strain AP1 utilized hexadecane, phenanthrene, and fluoranthene for growth. Pyrene-grown cells oxidized the methylenic groups of fluorene and acenaphthene and catalyzed the dihydroxylation and ortho cleavage of one of the rings of naphthalene and phenanthrene to give 2-carboxycinnamic and diphenic acids, respectively. The catabolic versatility of strain AP1 and its use of ortho cleavage mechanisms during the degradation of polycyclic aromatic hydrocarbons (PAHs) give new insight into the role that pyrene-degrading bacterial strains may play in the environmental fate of PAH mixtures.
分枝杆菌属菌株AP1能够以芘作为唯一碳源和能源生长。对生长过程中积累的代谢产物的鉴定表明,该菌株对芘的攻击起始于在其C-4、C-5位进行单加氧或双加氧反应,分别生成反式或顺式-4,5-二羟基-4,5-二氢芘。后者脱氢,所得二醇邻位裂解形成菲4,5-二羧酸,随后脱羧生成菲4-羧酸,通过邻苯二甲酸导致菲4-羧酸降解。一种鉴定为6,6'-二羟基-2,2'-联苯二甲酸的新型代谢产物表明该途径中存在一个新分支,该分支涉及芘两个中心环的裂解。除了芘,菌株AP1还利用十六烷、菲和荧蒽进行生长。以芘为生长底物的细胞氧化芴和苊的亚甲基,并催化萘和菲其中一个环的双羟基化和邻位裂解,分别生成2-羧基肉桂酸和联苯二甲酸。菌株AP1的分解代谢多样性及其在多环芳烃(PAHs)降解过程中对邻位裂解机制的利用,为芘降解细菌菌株在PAH混合物环境归宿中可能发挥的作用提供了新的见解。