Turova T P, Kovaleva O L, Gorlenko V M, Ivanovskiĭ R N
Mikrobiologiia. 2014 Jan-Feb;83(1):72-82.
This work examined the feasibility of using certain genes of carbon metabolism enzymes as molecular markers adequate for studying phylogeny and ecology of green sulfur bacteria (GSB) of the Chlorobi phylum. Primers designed to amplify the genes of ATP citrate lyase (aclB) and citrate synthase (gltA) revealed the respective genes in the genomes of all of the newly studied GSB strains. The phylogenetic trees constructed based on nucleotide sequences of these genes and amino acid sequences of the conceptually translated proteins were on the whole congruent with the 16S rRNA gene tree, with the single exception of GltA of Chloroherpeton thalassium, which formed a separate branch beyond the cluster comprised by other representatives of the Chlorobi phylum. Thus, the aclB genes but not gltA genes proved to be suitable for the design of primers specific to all Chlorobi representatives. Therefore, it was the aclB gene that was further used asa molecular marker to detect GSB in enrichment cultures and environmental samples. AclB phylotypes of GSB were revealed in all of the samples studied, with the exception of environmental samples from soda lakes. The identification of the revealed phylotypes was in agreement with the identification based on the FMO protein gene (fmo), is a well-known Chlorobi-specific molecular marker.
本研究探讨了将碳代谢酶的某些基因用作分子标记，以研究绿弯菌门绿硫细菌（GSB）的系统发育和生态学的可行性。设计用于扩增ATP柠檬酸裂解酶（aclB）和柠檬酸合酶（gltA）基因的引物，在所有新研究的GSB菌株基因组中均揭示了相应基因。基于这些基因的核苷酸序列和概念性翻译蛋白质的氨基酸序列构建的系统发育树，总体上与16S rRNA基因树一致，但嗜盐绿屈挠菌的GltA除外，它在绿弯菌门其他代表组成的簇之外形成了一个单独的分支。因此，事实证明aclB基因而非gltA基因适用于设计针对所有绿弯菌代表的特异性引物。因此，aclB基因进一步用作分子标记，以检测富集培养物和环境样品中的GSB。在所研究的所有样品中均揭示了GSB的AclB系统型，但苏打湖的环境样品除外。所揭示系统型的鉴定与基于FMO蛋白基因（fmo）的鉴定结果一致，fmo是一种著名的绿弯菌特异性分子标记。
