A novel radiation-resistant strain of Filobasidium sp. isolated from the West Sea of Korea.
A novel radiation-resistant Filobasidium sp. yeast strain was isolated from seawater. Along with this strain, a total of 656 yeast isolates were purified from seawater samples collected from three locations in the West Sea of Korea and assessed for their radiation tolerance. Among these isolates, five were found to survive a 5 kGy radiation dose. The most radiationresistant strain was classified as Filobasidium sp. based on 18S rDNA sequence analysis and hence was named Filobasidium RRY1 (Radiation-Resistant Yeast 1). RRY1 differed from F. elegans, which is closely related to RRY1, in terms of the optimal growth temperature and radiation resistance, and was resistant to high doses of γ-ionizing radiation (D10: 6-7 kGy). When exposed to a high dose of 3 kGy irradiation, the RRY1 cells remained intact and undistorted, with negligible cell death. When these irradiated cells were allowed to recover, the cells fully repaired their genomic DNA within 3 h of growth recovery. This is the first report in which a radiation-resistant response has been investigated at the physiological, morphological, and molecular levels in a strain of Filobasidium sp.
Research Division for Biotechnology, Korea Atomic Energy Research Institute, Jeongeup 580-185, Republic of Korea.
Harinder
H
Singh
Haram
H
Kim
Hyunpa
H
Song
Minho
M
Joe
Dongho
D
Kim
Yong-Sun
YS
Bahn
Jong-Il
JI
Choi
Sangyong
S
Lim
D001487:Basidiomycota / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification / Q000528:radiation effects*; D016000:Cluster Analysis; D004249:DNA Damage / Q000528:radiation effects; D004260:DNA Repair; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D005720:Gamma Rays; D020459:Genes, rRNA; D007723:Korea; D050296:Microbial Viability / Q000528:radiation effects*; D010802:Phylogeny; D012331:RNA, Fungal / Q000235:genetics; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012623:Seawater / Q000382:microbiology*; D017422:Sequence Analysis, DNA; D013696:Temperature
D004271:DNA, Fungal; D005227:Fatty Acids; D012331:RNA, Fungal; D012337:RNA, Ribosomal, 18S