A eukaryotic marine microalga was isolated from Jungmun Saekdal Beach, Jeju Island, Korea and an integrated approach, including molecular phylogeny and morphology, was used to determine its taxonomical status. Molecular phylogenetic evidence inferred from the small subunit (SSU) 18S rRNA sequence and internal transcribed spacer (ITS) secondary structure analysis clearly showed that the isolate belonged to the recently described species, Jaagichlorella roystonensis. Distinctive morphological keys of the species were also observed by light microscopy and scanning/ transmission electron microscopy (S/TEM). In this study, a Korean marine J. roystonensis species was described for the first time and was subsequently added to the national culture collections in Korea.

A eukaryotic microalga was isolated from seawater in Janghang Harbor, Korea and its morphological, molecular, and physiological characteristics were investigated. Due to its simple morphology, no distinctive characters were found by morphological observation, such as light microscope or scanning/transmission electron microscopy (S/ TEM). However, molecular phylogenetic evidence inferred from the concatenated small subunit (SSU) 18S rRNA and internal transcribed spacer (ITS) sequence data indicated that the isolate belonged to the newly described Micractinium singularis. Furthermore, it was clustered with Antarctic Micractinium strains and it also showed a psychrotolerant property, surviving at temperatures as low as 5°C. However, its optimal growth temperatures range from 15°C to 25°C, indicating that this microalga is a mesophile. Additionally, gas chromatography-mass spectrometry (GC/MS) analysis showed that the isolate was rich in nutritionally important omega-3 polyunsaturated fatty acid, and high-performance liquid chromatography analysis (HPLC) revealed that the high-value antioxidant lutein was biosynthesized as an accessory pigment by this microalga, with glucose as the major monosaccharide. Therefore, in this study, a Korean marine M. singularis species was discovered, characterized, and described. It was subsequently added to the national culture collections.

Chlorella gloriosa (Chlorellaceae, Trebouxiophyceae) was isolated from seawater off the coast of the Dokdo Islands in Korea. An axenic culture was established using the streak-plate method on f/2 agar media supplemented with antibiotics, allowing identification of the isolate by morphological, molecular, and physiological analyses. The morphological characteristics observed by light and electron microscopy revealed typical morphologies of C. gloriosa species. The molecular phylogenetic inference drawn from the small-subunit 18S rRNA sequence verified that the microalgal strain belongs to C. gloriosa. Additionally, gas chromatography-mass spectrometry analysis showed that the isolate was rich in nutritionally important omega-3 and -6 polyunsaturated fatty acids and high-performance liquid chromatography analysis revealed that the high-value antioxidants lutein and violaxanthin were biosynthesized as accessory pigments by this microalga, with arabinose, galactose, and glucose as the major monosaccharides. Therefore, in this study, a Korean marine C. gloriosa species was discovered, characterized, and described, and subsequently added to the national culture collection.

In 2017, the freshwater algae were collected from reservoirs, small ponds, soil, and rocks in Korea. Eight taxa of Chlorophyta (Chlorophyceae and Trebouxiophyceae) have been newly reported in Korea. The unrecorded indigenous species were Chlorolobion braunii, Coelastrum pseudomicroporum, Coelastrum reticulatum var. cubanum, Monoraphidium nanum, Tetrachlorella incerta, Ecdysichlamys obliqua, Gloeotila scopulina, and Stichococcus jenerensis.

한국 내 전국적으로 5곳의 담수에서 2010년 4월부터 2011년 6월에 걸쳐 담수시료를 채취한 후, 각 담수시료에서 Botryococcus braunii의 출현을 확인하고 microcapillary-pipetting method를 이용하여 5주를 분리하였다. 분리된 B. braunii의 18S rRNA sequencing 후, BLAST search를 통한 분석 결과는 B. braunii와 가장 높은 상동성을 나타낸 것으로 확인되어 형태적 동정결과와 일치하였다. 진화, 계통분류학적 분석결과, 분리된 5주의 B. braunii는 단일 계통인 Trebouxiophyceae으로 분류되었다. 18S rRNA sequence의 계통 분류학적 분석에서 B. braunii KNU6는 다른 분리된 B. braunii와 같은 분류군 내에서 거리의 차이가 있었고, 또한 세포크기, 점액질의 양 등의 형태적 특징도 차이를 보였다. 한국에서 분리된 5주의 B. braunii는 모두 race A type의 분류군에 포함되며, 탄소수 C23-C33의 지방산에서 유래된 alkadienes과 alkatrienes를 생산하는 것으로 사료되며, B. braunii를 이용한 바이오디젤을 생산하기 위한 최적의 배양조건을 찾는 연구가 필요하다.