A new species of the genus Haematococcus (Chlorophyta) and its distribution in Korea

Abstract

The genus Haematococcus is a green microalga which forms red cyst under stress condition and becomes the richest source of astaxanthin. In search of useful microalgae in Korea, water samples from different places including retained water on the roof of multi-storied building were observed under inverted light microscope. The microscopic observation of our strain revealed similar morphological characteristics with other Haematococcus sp. therefore, for confirmation, the strain was isolated and grown as axenic strain for molecular analysis which was done with 18s rDNA and rbcL sequences. The sequence of 1,748 bp of 18s rDNA is highly similar to those of H. lacustris and H. pluvialis (99 and 98%, respectively). In its molecular phylogeny, the organism was placed within the Haematococcus genus with high bootstrap support (100%). The phylogenetic analysis of the rbcL gene also demonstrated that the isolated organism belongs to the Haematococcus genus. On the other hand, the rbcL gene sequence (1,102 bp) differs by more than 4% from those of the known Haematococcus species, implying that the organism is a separate species level taxon compared to the known species. Therefore, we report the newly found organism as a new species in the genus Haematococcus, and proposed naming will be Haematococcus koreana. In the natural sample, higher cell abundance was found in spring, followed by early autumn and summer with the temperature and pH variation of 24 to 28？C and 7.4 to 8.8, respectively. H. koreana was found on 2 two 3 stories building…s roof where some water was retained after rain or any bucket or water holding pots being left. It was found in Kyongyu Bomoon lake and lake Shiwa of South-East and North-West part, at Dongjin irrigation canal on South-West part, at the tiny freshwater pole on the small island which was 30 meter far from seawater at Tongyeong, South part, Korea. Further study is needed to develop mass culture system for various uses.