盐土生古菌属(Haloterrigena)分类研究进展

Research advances on classification of the genus Haloterrigena

盐土生古菌属(Haloterrigena)是一类生长在含有1.7~5.5 mol/L NaCl、17~60℃温度范围内的极端嗜盐古菌。自该属1999年被建立以来,目前已有10个种被有效发表。但是在基于16S rRNA或rpoB’基因的系统进化树上,盐土生古菌属物种常与碱线菌属(Natrinema)和嗜盐碱红菌属(Natronorubrum)的成员交叉聚类在一起;而且盐土生古菌属内各成员间的特征也不尽相同,如多数盐土生古菌属菌株生长pH范围6.0~9.0,最适pH 7.0~7.5,然而大庆盐土生古菌(Haloterrigena daqingensis)为该属的唯一嗜碱成员,生长pH在8.0~10.5,最适为pH 10.0;在化学分类特征方面,该属的多数菌株含有糖脂类型为双硫化二糖基二醚(disulfated diglycosyl diether,S2-DGD-1),然而伊斯帕尼亚盐土生古菌(Haloterrigena hispanica)菌株FP1含有S-DGD硫酸化二糖基二醚(sulfated diglycosyl diether)。鉴于该属存在的这些特殊特征,以及与碱线菌属和嗜盐碱红菌属在系统进化上的特殊关系,结合前期发表的该属的新种和相关文献资料,系统综述了盐土生古菌属的建立、分类学特征、生态分布、基因组信息等方面的研究进展,以期为盐土生古菌属已知种分类地位的确定、该属其他新分离菌株的分类鉴定、功能基因资源的挖掘与开发提供借鉴。

The genus Haloterrigena is a group of extremely halophlic archaea growing in the range of 1. 7~5. 5 mol/L NaCl(w/v)and temperature 17~60 ℃. Since the establishment of this genus in 1999,10 validly named species have been reported. However,some species of the genus Haloroterrigena usually cross-cluster with members of the genera Natrinema and Natronorubrum in the phylogenetic tree based on 16S rRNA or rpoB’ genes. In addition,there are some significant differences in characteristics among members of the genus Haloterrigena. For example,most Haloterrigena strains grow at pH 6. 0~9. 0(optimum at pH 7. 0~7. 5),however,Haloterrigena daqingensis can only grow at pH8. 0~10. 5(optimum growth at pH 10. 0),and it is the only alkaliphilic member of the Haloterrigena genus. Referring to the chemotaxonomic characteristics,most strians of this genus contain glycolipids of disulfated diglycosyl diether(S2-DGD-1),whereas Htg. hispanica strain FP1 contains another glycolipid,sulfated diglycosyl diether(S-DGD). In view of the existence of these special characteristics of the genus and the special phylogenetic relationships with the genera Natrinema and Natronorubrum,the present paper deals with the new species of the genus and the related literature,and the establishment,taxonomic features,ecological distribution and genomic information of the genus Haloterrigena are reviewed. The aim of this study is to provide references for the classification of known species,the identification of other new isolates of Haloterrigena,and the excavation and exploitation of functional gene resources.