Three New Plectolyngbya Species (Leptolyngbyaceae, Cyanobacteria) Isolated from Rocks and Saltern of the Republic of Korea

Abstract

Thin filamentous cyanobacteria isolated from three collection sites in the Republic of Korea were suggested as three new species belonging to the genus Plectolyngbya, mainly according to their molecular characteristics. The species of Plectolyngbya, including the type species of P. hodgsonii, were cryptic species that were difficult to distinguish morphologically from each other, and had appeared in ecologically diverse habitats. P. terrestris and P. koreana were subaerophytes collected from certain black spots and soils between stone walls in Seoul, Republic of Korea. In addition, hypersaline species collected from a saltern, P. salina, shared the same halophytic feature as the P. hodgsonii from the littoral zone of a coastal lake in the Antarctic. The 16S rRNA gene phylogeny supported the monophyly of Plectolyngbya with solid support, 99% Maximum Likelihood, 98% Neighbor-Joining bootstrap support values, and 1.0 Bayesian posterior probability. The ITS sequences of P. terrestris, P. koreana, and P. salina were unique in length and nucleotide composition, with different secondary structures of D1-D1MODIFIER LETTER PRIME and Box-B helices, compared with those of P. hodgsonii. These results demonstrate that the proposed new Plectolyngbya species were unique in their molecular traits. Therefore, we suggest them as new species belonging to the genus Plectolyngbya with the names P. terrestris sp. nov., P. koreana sp. nov., and P. salina sp. nov.