Labrys okinawensis sp. nov. and Labrys miyagiensis sp. nov., budding bacteria isolated from rhizosphere habitats in Japan, and emended descriptions of the genus Labrys and Labrys monachus

Abstract

Three strains, MAFF 210191T, G24103T and G24116, assumed to be members of two novel species, were isolated from several rhizosphere habitats in different parts of Japan. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolates formed a distinct monophyletic group together with the two known species of the genus Labrys, suggesting that the isolates have a close affiliation with this genus. In this study, a polyphasic approach was used to characterize and compare the three isolates with the two species of the genus Labrys, Labrys monachus and Labrys methylaminiphilus. All three isolates were aerobic, Gram-negative, motile and non-sporulating and they ranged in shape from spherical to short rods. The cells multiplied by budding and utilized a wide variety of monosaccharides, disaccharides and sugar alcohols as sole carbon and energy sources, but they did not utilize C1 compounds, salicin or d-melezitose. The strains were inhibited by dl-α-alanine and glycine (both at 10 mM). The major cellular fatty acids were C19 : 0 cyclo ω8c, C16 : 0, C18 : 0 and C18 : 1 ω7c. The three isolates shared <12 % and <11 % DNA–DNA relatedness with L. monachus DSM 5896T and L. methylaminiphilus DSM 16812T, respectively. The G+C content of the isolates (61–62 mol%) was also significantly lower than those of the two previously characterized species. In spite of many morphological, physiological and chemotaxonomic similarities among the three isolates, strain MAFF 210191T could be differentiated from strains G24103T and G24116 on the basis of 16S rRNA gene sequence divergence, DNA–DNA relatedness (<46 %) and gelatin hydrolysis. Two novel species are therefore proposed, namely Labrys okinawensis sp. nov., with the type strain MAFF 210191T (=DSM 18385T), and Labrys miyagiensis sp. nov., with the type strain G24103T (=NBRC 101365T=NCIMB 14143T) and also including strain G24116 (=NBRC 101366=NCIMB 14144). Emended descriptions of the genus Labrys and Labrys monachus are also presented.

Acetylation of fluoroquinolone antimicrobial agents by anEscherichia colistrain isolated from a municipal wastewater treatment plant

“…(Raj and Maloy 1990) and Labrys sp. (Islam et al. 2007) are also generally considered to be environmental bacteria.…”

Labrys portucalensis sp. nov., a fluorobenzene-degrading bacterium isolated from an industrially contaminated sediment in northern Portugal

“…While this paper was in press, three additional species of the genus Labrys have been described, Labrys miyagiensis and Labrys okinawensis (Islam et al, 2007) and Labrys neptuniae (Chou et al, 2007).…”

Labrys wisconsinensis sp. nov., a budding bacterium isolated from Lake Michigan water, and emended description of the genus Labrys

“…Based upon 16S rRNA gene sequencing, both strains appeared to be novel species of the genus Labrys. The genus Labrys currently contains six recognized species of budding bacteria, including Labrys monachus (Vasil'eva & Semenov, 1984), Labrys methylaminiphilus (Miller et al, 2005), Labrys okinawensis (Islam et al, 2007), Labrys miyagiensis (Islam et al, 2007), Labrys neptuniae (Chou et al, 2007) and Labrys portucalensis (Carvalho et al, 2008), all of which were isolated from a variety of soil and sediment samples.…”

“…Prior to inoculation, plates were incubated at the test temperature for 24 h. After inoculation, plates were incubated for up to 7 days. The ability to utilize various carbohydrates as growth substrates and various nitrogen sources was evaluated according to Islam et al (2007) with some modifications. Tubes containing 5 ml growth medium were incubated with shaking aeration for 7 days.…”