Alcanivorax balearicus sp. nov., isolated from Lake Martel

Abstract

A bacterial strain designated MACL04T was isolated from Lake Martel, a subterraneous saline lake in Mallorca (Spain). The complete 16S rRNA gene sequence of this strain showed nearly 100 % similarity to that of Alcanivorax dieselolei B-5T. Despite this high similarity, strain MACL04T showed phenotypic, chemotaxonomic and molecular differences with respect to A. dieselolei, indicating that strain MACL04T represents a separate species. Cells of strain MACL04T were motile by means of a single polar or subpolar flagellum and colonies formed on media containing 1 % (v/v) Tween 20 were opaque and mucoid, with blue–green iridescence. The generation time of strain MACL04T in this medium was approximately half that of A. dieselolei B-5T and strain MACL04T did not produce lipases after incubation for 5 days. Strain MACL04T did not require NaCl for growth and grew in the presence of up to 15 % (w/v) NaCl. The strain was able to use alkanes as a sole carbon source; however, glucose could also be used, albeit weakly, as a carbon source. Several amino acids and organic acids were used as carbon sources. Strain MACL04T produced acid in media containing pyruvate as the sole carbon source. The major fatty acids were C19 : 0 cyclo ω8c and C16 : 0. The fatty acid C16 : 1 ω8c, present in strain MACL04T, was not detected in the recognized Alcanivorax species. The sequences of the large and short 16S–23S intergenic spacer regions showed similarities of 97.2 and 98.8 % (ungapped) with respect to A. dieselolei B-5T. Partial sequences of gyrB and alkb genes showed 94.0 % similarity between strain MACL04T and A. dieselolei B-5T. The G+C content of strain MACL04T was 62.8 mol%. The data from this polyphasic study indicate that strain MACL04T represents a novel species of the genus Alcanivorax, for which the name Alcanivorax balearicus sp. nov. is proposed. The type strain is MACL04T (=LMG 22508T=CECT 5683T).