Arthrobacter psychrochitiniphilus sp. nov., a psychrotrophic bacterium isolated from Antarctica.

A psychrotrophic Arthrobacter strain, GP3(T), was isolated from Adélie penguin guano from Antarctica and characterized. The 16S rRNA gene sequence of the novel strain showed the highest similarity (97.8 %) with that of Arthrobacter psychrolactophilus B7(T). The novel strain showed a morphological change from rod to coccus. The growth temperature range of strain GP3(T) was 0-25 degrees C, with optimal growth at 20 degrees C. The strain grew over a salinity range of between 0 and 3 % (w/v) NaCl and the optimal pH for growth was pH 6-8. Strain GP3(T) contained anteiso-C(15 : 0) as the major fatty acid. The major menaquinone was MK-9(H(2)). The cell-wall peptidoglycan type was of the A3alpha variant. The DNA G+C content of strain GP3(T) was 58.5 mol%. Strain GP3(T) was able to hydrolyse chitin, Tween 80, starch, cellulose and lactose, but not gelatin, lecithin or urea. In addition to these physiological characteristics, DNA-DNA hybridization studies clearly differentiated strain GP3(T) from A. psychrolactophilus. The combined results of phylogenetic, physiological and chemotaxonomic studies indicated that strain GP3(T) represents a novel species of the genus Arthrobacter. The name Arthrobacter psychrochitiniphilus sp. nov. (type strain GP3(T)=JCM 13874(T)=CGMCC 1.6355(T)) is proposed in recognition of the strain's strong chitin-utilizing ability.