Leifsonia psychrotolerans sp nov., a psychrotolerant species of the family Microbacteriaceae from Livingston Island, Antarctica

A cold-tolerant, yellow-pigmented, Gram-positive, motile, facultatively anaerobic bacterial strain, LI1(T), was isolated from a moss-covered soil from Livingston Island, Antarctica, near the Bulgarian station St. Kliment Ohridski. Comparative 16S rRNA gene sequence-based phylogenetic analysis placed the strain in a clade with the species Leifsonia kafniensis KFC-22(T), Leifsonia pindariensis PON10(T) and Leifsonia antarctica SPC-20(T), with which it showed sequence similarities of 99.0, 97.9 and 97.9%, respectively. DNA DNA hybridization revealed a reassociation value of 2.7% with L. kafniensis LMG 24362(T). The DNA G content of strain LI1(T) was 64.5 mol%. The growth temperature range was -6 to 28 degrees C, with optimum growth at 16 degrees C. Growth occurred in 0-5% NaCl and at pH 4.5-9.5, with optimum growth in 1-2% NaCl and at pH 5.5-6.5. The predominant fatty acids were anteiso-C(15:0), C(18:0) and iso-C(15:0). The polar lipids were phosphatidylglycerol and diphosphatidylglycerol. Physiological and biochemical tests clearly differentiated strain LI1(T) from L. kafniensis. Therefore, a novel cold-tolerant species within the genus Leifsonia is proposed: Leifsonia psychrotolerans sp. nov. (type strain LI1(T)=DSM 22824(T)=NCCB 100313(T)).