Arenimonas malthae sp. nov., a gammaproteobacterium isolated from an oil-contaminated site.

A Gram-negative, rod-shaped bacterium (CC-JY-1(T)) was isolated on nutrient agar from a soil sample collected from an oil-contaminated site located in Chyai county, Taiwan. 16S rRNA gene sequence analysis demonstrated that this isolate is unique, showing 96.7 % sequence similarity to the type strain of Arenimonas donghaensis and similarities of 93.0-93.8 % to species of the genera Thermomonas, Lysobacter and Silanimonas. The presence of ubiquinone Q-8, a polar lipid profile consisting of the major compounds diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine and the fatty acid profile were in accordance with the phylogenetic affiliation of CC-JY-1(T). DNA-DNA reassociation experiments between CC-JY-1(T) and A. donghaensis KACC 11381(T) resulted in a mean relatedness value of 32 %, indicating that strain CC-JY1(T) represents a novel species in the genus Arenimonas, for which we propose the name Arenimonas malthae sp. nov. The type strain is CC-JY-1(T) (=CCUG 53596(T) =CIP 109310(T)).

Rhodanobacter ginsengisoli sp. nov. and Rhodanobacter terrae sp. nov., isolated from soil cultivated with Korean ginseng.

Two bacterial isolates from ginseng fields in Korea, strains GR17-7(T) and GP18-1(T), were characterized using a polyphasic approach. Phylogenetic analysis of their 16S rRNA gene sequences revealed a clear affiliation with the Gammaproteobacteria, and showed that the closest phylogenetic relationships were with members of the genus Rhodanobacter. The 16S rRNA gene sequence similarity between strains GR17-7(T) and GP18-1(T) was 97.2 %. Both strains showed 16S rRNA gene sequence similarities of 95.2-96.9 % to type strains of recognized Rhodanobacter species. The G+C contents of the DNA of strains GR17-7(T) and GP18-1(T) were 61.0 and 62.5 mol%, respectively. According to the DNA-DNA hydridization tests, the hybridization value between strains GR17-7(T) and GP18-1(T) was 34 %. Strains GR17-7(T) and GP18-1(T) showed less than 32 % DNA-DNA relatedness with Rhodanobacter fulvus KCTC 12098(T) and Rhodanobacter spathiphylli LMG 23181(T). Strains GR17-7(T) and GP18-1(T) were aerobic, Gram-negative, rod-shaped, and catalase- and oxidase-positive. Major fatty acids of both strains were iso-C(17 : 1)omega9c and iso-C(16 : 0). Based on the data presented, two novel Rhodanobacter species are proposed, with the names Rhodanobacter ginsengisoli sp. nov. (type strain GR17-7(T)=KACC 11762(T)=DSM 18993(T)) and Rhodanobacter terrae sp. nov. (type strain GP18-1(T)=KACC 11761(T)=DSM 19241(T)).

Pseudoxanthomonas spadix sp. nov., isolated from oil-contaminated soil.

A bacterial isolate from a sample of oil-contaminated soil was characterized using a polyphasic taxonomic approach. Comparative analysis of the 16S rRNA gene sequence showed that this isolate constituted a distinct phyletic line within the genus Pseudoxanthomonas, displaying >3.7 % sequence divergence with respect to recognised Pseudoxanthomonas species. The genus assignment was confirmed by a chemotaxonomic analysis, which revealed the presence of a fatty acid profile characteristic of members of the genus Pseudoxanthomonas (straight-chain saturated, unsaturated and branched-chain fatty acids of the iso/anteiso type and 3-hydroxylated fatty acids) and the presence of a ubiquinone with eight isoprene units (Q-8) as the predominant respiratory quinone. The novel isolate was distinguishable from other members of the genus Pseudoxanthomonas on the basis of a combination of phenotypic properties. The genotypic and phenotypic data show that the strain represents a novel species of the genus Pseudoxanthomonas, for which the name Pseudoxanthomonas spadix sp. nov. is proposed. The type strain is IMMIB AFH-5(T) (=DSM 18855(T)=CCUG 53828(T)).

Pseudoxanthomonas kaohsiungensis, sp. nov., a novel bacterium isolated from oil-polluted site produces extracellular surface activity.

During screening for biosurfactant-producing bacteria, a strain designated J36T was isolated from oil-polluted site near Kaohsiung city located in southern Taiwan. Cells of this organism were gram-negative rods motile by means of a single polar flagellum. Strain J36T grew well in complex media under optimum conditions of 35 degrees C and pH 7. The extracellular products of the strain expressed emulsification activity. During cultivation on olive oil as the sole carbon and energy source, the culture supernatant of strain J36T reduced surface tension of the medium from 68 to 32.6 dyne/cm. The 16S rRNA gene sequence analysis indicates that strain J36T is a member of Xanthomonas group within the gamma-Proteobacteria. The organism belongs to the genus Pseudoxanthomonas and represents a novel species within this genus according to phylogenetic analysis of 16S rDNA sequences, DNA-DNA similarity data, whole-cell protein analysis, physiological and biochemical characteristics, as well as fatty acid compositions. The predominant cellular fatty acids of strain J36T were 15:0 iso (about 26%), 17:1 iso omega9c (about 25%), and 15:0 anteiso (about 10%). Its DNA base ratio was 60.1 mol% G+C. We propose to classify strain J36T (= BCRC 17375T = LMG 22530T) as Pseudoxanthomonas kaohsiungensis sp. nov.

Pseudoxanthomonas koreensis sp. nov. and Pseudoxanthomonas daejeonensis sp. nov.

Gram-negative, non-spore-forming, rod-shaped bacteria, T7-09(T) and TR6-08(T), were isolated from soil from a ginseng field in South Korea and characterized to determine their taxonomic position. 16S rRNA gene sequence analysis showed that the two isolates shared 99.5 % sequence similarity. Strains T7-09(T) and TR6-08(T) were shown to belong to the Proteobacteria and showed the highest levels of sequence similarity to Pseudoxanthomonas broegbernensis DSM 12573(T) (98.1 %), Pseudoxanthomonas mexicana AMX 26B(T) (97.4-97.5 %), Pseudoxanthomonas japonensis 12-3(T) (96.5-96.6 %), Pseudoxanthomonas taiwanensis ATCC BAA-404(T) (95.7 %) and Xanthomonas campestris ATCC 33913(T) (96.3-96.5 %). The sequence similarity values with respect to any species with validly published names in related genera were less than 96.5 %. The detection of a quinone system with Q-8 as the predominant compound and a fatty acid profile with C(15 : 0) iso as the predominant acid supported the assignment of the novel isolates to the order 'Xanthomonadales'. The two isolates could be distinguished from the established species of the genus Pseudoxanthomonas by the presence of quantitative unsaturated fatty acid C(17 : 1) iso omega9c and by their unique biochemical profiles. The results of DNA-DNA hybridization clearly demonstrated that T7-09(T) and TR6-08(T) represent separate species. On the basis of these data, it is proposed that T7-09(T) (=KCTC 12208(T)=IAM 15116(T)) and TR6-08(T) (=KCTC 12207(T)=IAM 15115(T)) be classified as the type strains of two novel Pseudoxanthomonas species, for which the names Pseudoxanthomonas koreensis sp. nov. and Pseudoxanthomonas daejeonensis sp. nov., respectively, are proposed.