Neomicrocoleus gen. nov. (Microcoleaceae, Oscillatoriales), a novel cyanobacterial genus from benthic mats in a water channel.

A new filamentous cyanobacterial strain (CHAB 4127) was successfully isolated from the algal mat during the field investigation of the open channel from Luanhe River to Tianjin, China. The polyphasic approach combining morphological, ultrastructural, ecological, and molecular features was used to characterize this studied strain. The strain is morphologically similar to the Microcoleus-like cyanobacterial taxa under light microscopy, and the radial arrangement of thylakoids is also consistent with that of Microcoleus-like groups. The phylogenetic position of CHAB 4127 based on 16S rRNA gene sequences, is shown to be clearly clustered into an independent clade with the newly established genus Microcoleusiopsis. The maximum similarity of 16S rRNA gene of the studied strain with other existing related cyanobacterial taxa is 93.97%, and the ITS secondary structures is also obviously different from other members of Microcoleaceae. Based on all the above evidence, we proposed the establishment of this novel cyanobacterial genus as Neomicrocoleus, with its type species, Neomicrocoleus tianjinensis. [ABSTRACT FROM AUTHOR]