Actinobacterial diversity in a coastal wetland of the Yellow River Delta revealed by culture-independent approach

Abstract:

[Objective] Using culture-independent method to analyze the diversity of actinomyces from Yellow River Delta coastal wetland. [Methods] Actinobacterium-specific 16S rRNA gene clone library was constructed. Representative clones selected based on the RFLP analysis were sequenced and placed into operational taxonomic unit (OTU) groups according to the 16S rRNA sequence similarity. Diversity statistics were analyzed using SPADE analysis software. [Results] 324 sequences were placed into 46 OTUs. 58.7% of the OTUs belonged to Actinobacteridae and 7 suborders of Actinomycetales. The dominant actinobacteria was Frankineae, which accounted for 7 OTUs. 30.4% of the OTUs belonged to subclass Aci-dimicrobidae and suborder Acidimicrobineae. 10.9% of the OTUs shared no close relationship with published sequences. Some sequences which formed a distinct clade in phylogenetic tree may represent new taxonomical groups of actinomyces. [Conclusion] Yellow River Delta coastal wetland harbors abundant and diverse actinomyces. The result also implied that there may be large numbers of unknown actinobacterial groups.