Arthrobacter flavus sp. nov., a psychrophilic bacterium isolated from a pond in McMurdo Dry Valley, Antarctica

• Main Authors: Reddy, G. S., Aggarwal, R. K., Matsumoto, G. I., Shivaji, S.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Society for General Microbiology 2000
• Subjects: QL Zoology; Antarc*; Antarctica
• Online Access: http://repository.ias.ac.in/64296/; http://ijs.sgmjournals.org/content/50/4/1553.abstract?sid=a193c8f8-97a3-49ff-936a-9392ecc4141c

CMS 19Y T , a psychrophilic bacterium, was isolated from a cyanobacterial mat sample from a pond in Antarctica and was characterized taxonomically. The bacterium was aerobic, gram-positive, non-spore-forming, non-motile, exhibited a rod-coccus growth cycle and produced a yellow pigment that was insoluble in water but soluble in methanol. No growth factors were required and it was able to grow between 5 and 30 ° C, between pH 6 and pH 9 and tolerated up to 11·5% NaCl. The cell wall peptidoglycan was Lys-Thr-Ala3 (the A3α variant) and the major menaquinone was MK-9(H 2 ). The G+C content of the DNA was 64±2 mol%. The 16S rDNA analysis indicated that CMS 19Y T is closely related to group I Arthrobacter species and showed highest sequence similarity (97.91%) with Arthrobacter agilis. Furthermore, DNA-DNA. hybridization studies also indicated 77% homology between CMS 19Y T and A. agilis. It differed from A. agilis, however, in that it was psychrophilic, non-motile, yellow in colour, exhibited a rod-coccus growth cycle, had a higher ° of tolerance to NaCl and was oxidase- and urease-negative and lipase-positive. In addition, it had a distinct fatty acid composition compared to that of A. agilis: the predominant fatty acids were C 15:0 , anteiso-C 15:0 , C 16:0 , iso-C 16:0 , C 17:0 , anteiso-C 17:0 and C 18:0 . It is proposed, therefore, that CMS 19Y T should be placed in the genus Arthrobacter as a new species, i.e. Arthrobacter flavus sp. nov. The type strain of A. flavus is CMS 19Y T (= MTCC 3476 T ).