Deinococcus lacus sp. nov., a gamma radiation-resistant bacterium isolated from an artificial freshwater pond.

ABSTRACT

A Gram-stain-negative, pink-coloured, non-motile and gamma radiation-resistant bacterium, designated strain IMCC1711T, was isolated from a freshwater sample collected from an artificial pond (Inkyong Pond). The 16S rRNA gene sequence analysis showed that strain IMCC1711T was most closely related to Deinococcus piscis 3axT (94.2 %) and formed a robust phylogenetic clade with other species of the genus Deinococcus. Optimal growth of strain MCC1711T was observed at 25 °C and pH 7.0 without NaCl. Strain IMCC1711T exhibited high resistance to gamma radiation. The DNA G+C content of strain IMCC1711T was 59.1 mol% and MK-8 was the predominant isoprenoid quinone. Major fatty acid constituents of the strain were C17  1ω8c, C16  0, summed feature 3 (C16  1ω6c and/or C16  1ω7c) and C15  1ω6c. The major polar lipids constituted phosphatidylethanolamine, one unidentified phosphoglycolipid and two unidentified glycolipids. On the basis of taxonomic data obtained in this study, it was concluded that strain IMCC1711T represented a novel species of the genus Deinococcus, for which the name Deinococcus lacus sp. nov. is proposed. The type strain of Deinococcus lacus is IMCC1711T (KCTC 52494T=KACC 18979T=NBRC 112440T).