Wei-An Lai

Azospirillum rugosum sp nov., isolated from oil-contaminated soil

The taxonomic status of a light-orange-coloured bacterial isolate from an oil-contaminated soil sample was characterized by using a polyphasic taxonomic approach. Comparative analysis of 16S rRNA gene sequences demonstrated that the isolate belonged phylogenetically to the genus Azospirillum, with Azospirillum canadense, Azospirillum brasilense and Azospirillum doebereinerae as its closest phylogenetic relatives (97.3, 97.0 and 97.0 % similarity, respectively). DNA-DNA pairing studies showed that the unidentified organism displayed 25.0, 17.0 and 19.0 % relatedness to the type strains of A. brasilense, A. canadense and A. doebereinerae, respectively. The generic assignment was confirmed by chemotaxonomic data, which revealed a fatty acid profile that was characteristic of the genus Azospirillum, consisting of straight-chain saturated and unsaturated fatty acids with C18 : 1 omega 7c as the major fatty acid, and ubiquinone with ten isoprene units (Q-10) as the predominant respiratory quinone. On the basis of both the phenotypic and molecular genetic evidence, it is proposed that the unknown isolate be classified as a representative of a novel species of the genus Azospirillum, for which the name Azospirillum rugosum sp. nov. is proposed. The type strain is IMMIB AFH-6T (=CCUG 53966T=DSM 19657T).

Chromobacterium aquaticum sp nov, isolated from spring water samples

Strain CC-SEYA-1T, a motile, Gram-negative, non-violet-pigmented bacterium, was isolated on nutrient agar from spring-water samples collected from Yang-Ming Mountain, Taipei County, Taiwan. 16S rRNA gene sequence studies showed that the strain clustered with Chromobacterium violaceum (96.8 % similarity) and Chromobacterium subtsugae (96.5 % similarity), followed by Aquitalea magnusonii (95.8 % similarity). The fatty acid profile was slightly different from those reported for C. violaceum, C. subtsugae and A. magnusonii. The results of DNA-DNA hybridization, and physiological and biochemical tests allowed both genotypic and phenotypic differentiation of the isolate from the described Chromobacterium species. It is evident from the data obtained that the strain should be classified as a novel species in the genus Chromobacterium. The name proposed for this taxon is Chromobacterium aquaticum sp. nov.; the type strain is CC-SEYA-1T (=CCUG 55175T=BCRC 17769T).

Novosphingobium arabidopsis sp. nov., a DDT-resistant bacterium isolated from the rhizosphere of Arabidopsis thaliana

An aerobic, Gram-stain-negative, rod-shaped, DDT-resistant bacterium, designated strain CC-ALB-2(T), was isolated from the Arabidopsis thaliana rhizosphere. Strain CC-ALB-2(T) was able to grow at 25-37 °C, at pH 5.0-8.0, with 1.0% (w/v) NaCl and tolerate up to 200 mg l(-1) DDT. 16S rRNA gene sequence analysis of strain CC-ALB-2(T) showed highest sequence similarity to Novosphingobium stygium KCTC 2891(T) (97.1%) and Novosphingobium soli DSM 22821(T) (96.8%), and lower levels of similarity (<97.0%) to other species of the genus Novosphingobium. The major fatty acid profile consisted of C14 : 0 2-OH (13.1%), C16 : 0 (10.0%), C(15 : 0) iso 3-OH (5.8%), C(16: 1)ω7c/C(16 :1)ω6c (summed feature 3, 24.7%) and C(18 : 1)ω7c/C(18 : 1)ω6c (summed feature 8, 42.4%). The polar lipid profile constitutes sphingoglycolipid, glycolipid, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylglycerol and phosphatidylcholine. The polyamine pattern showed a predominance of spermidine as the major polyamine. The predominant quinone system was ubiquinone (Q-10). The DNA G+C content was 68.9 ± 0.1 mol%. Based on the phylogenetic, phenotypic and chemotaxonomic features, strain CC-ALB-2(T) is proposed to represent a novel species of the genus Novosphingobium for which the name Novosphingobium arabidopsis sp. nov. is proposed. The type strain is CC-ALB-2(T) ( = BCRC 80571(T) = JCM 18896(T)).

Azospirillum picis sp. nov., isolated from discarded tar

A polyphasic taxonomic study was performed on a pink-coloured unknown bacterium isolated from discarded road tar. Comparative analysis of the 16S rRNA gene sequence demonstrated that the isolate belongs phylogenetically to the genus Azospirillum with Azospirillum lipoferum, A. melinis and A. rugosum as its closest phylogenetic relatives (96.7, 96.6 and 96.6 % similarity to the respective type strains). The generic assignment was confirmed on the basis of chemotaxonomic data, which revealed a fatty acid profile characteristic for the genus Azospirillum, consisting of straight-chain saturated and unsaturated fatty acids, with C(18 : 1)omega7c as the major unsaturated non-hydroxylated fatty acid, and C(16 : 0) 3-OH as the major hydroxylated fatty acid, and a ubiquinone with ten isoprene units (Q-10) as the predominant respiratory quinone. On the basis of both the phenotypic and molecular genetic evidence, it is proposed that the unknown isolate should be classified within a novel species of the genus Azospirillum, for which the name Azospirillum picis sp. nov. is proposed. The type strain is IMMIB TAR-3(T) (=CCUG 55431(T) =DSM 19922(T)).

Sphingomonas formosensis sp. nov., a polycyclic aromatic hydrocarbon-degrading bacterium isolated from agricultural soil

In the present study, a yellow-pigmented, Gram-negative, short rod-shaped novel bacterium that was capable of degrading a wide range of polycyclic aromatic hydrocarbons (naphthalene, phenanthrene and pyrene) was isolated from agricultural soil located in Yunlin County, Taiwan. Comparative 16S rRNA gene sequence analysis positioned the novel strain in the genus Sphingomonas as an independent lineage adjacent to a subclade containing Sphingomonas fennica K101(T), Sphingomonas histidinilytica UM2(T), Sphingomonas wittichii RW1(T) and Sphingomonas haloaromaticamans A175(T). 16S rRNA gene sequence analysis of strain CC-Nfb-2(T) showed highest sequence similarity to S. fennica K101(T) (96.2%), S. histidinilytica UM2(T) (96.1%), S. wittichii RW1(T) (95.9%), S. haloaromaticamans A175(T) (95.7%), and Sphingobium ummariense RL-3(T) (94.7%); lower sequence similarities were observed with strains of all other Sphingomonas species. The strain contained phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid and diphosphatidylglycerol. The predominant fatty acids were summed feature 8 (C(18:1)ω7c and/or C(18:1)ω6c) C(16:0) and 11-methyl C(18:1)ω7c; C(14:0) 2-OH was the major 2-hydroxy fatty acid. Previously, these lipids have been found to be characteristic of members of the genus Sphingomonas. The serine palmitoyl transferase gene (spt) was also detected and sphingolipid synthesis was confirmed. The predominant isoprenoid quinone system was ubiquinone (Q-10) and the isolate contained sym-homospermidine as the major polyamine. The DNA G+C content of the isolate was 62.8±0.8 mol%. On the basis of chemotaxonomic, phenotypic and phylogenetic data, strain CC-Nfb-2(T) represents a novel species within the genus Sphingomonas, for which the name Sphingomonas formosensis sp. nov. is proposed; the type strain is CC-Nfb-2(T) (=BCRC 80272(T)=DSM 24164(T)).

Sphingomicrobium astaxanthinifaciens sp. nov., an astaxanthin-producing glycolipid-rich bacterium isolated from surface seawater and emended description of the genus Sphingomicrobium.

A Gram-stain-negative, rod-shaped, strictly aerobic, flagellated and non-spore-forming marine bacterium designated strain CC-AMO-30B(T) was isolated from coastal surface seawater, Taiwan. Strain CC-AMO-30B(T) synthesized astaxanthin [40 µg (g dry weight)(-1)] and formed reddish-orange-coloured colonies on marine agar (Difco 2216). The strain showed highest pairwise 16S rRNA gene sequence similarity to Sphingomicrobium lutaoense CC-TBT-3(T) (96.4%) followed by other members of the family Sphingomonadaceae (<94%) and established a discrete phyletic lineage associated with the former. The polar lipid profile constituted a remarkable number of unidentified glycolipids (GL1-8), in addition to diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid and two unidentified lipids (L1-2). The major fatty acids (>5% of total fatty acids) were C(18:1)ω7c/C(18:1)ω6c (summed feature 8), C(16:1)ω7c/C(16:1)ω6c (summed feature 3), C(18:1) 2-OH, methyl C(18:1)ω7c, C(17:1)ω6c and C(16 : 0). DNA G+C content was 70.6%; major respiratory quinone was ubiquinone Q-10; predominant polyamine was the triamine sym-homospermidine. Chemotaxonomic evidence including characteristic glycolipid profile, presence of significant amounts of C(18:1) 2-OH and absence of typical hydroxylated fatty acids such as C(14:0) 2-OH, C(15:0) 2-OH and C(16:0) 2-OH in considerable amounts, accompanied by phylogenetic distinctiveness and several other phenotypic features support the classification of strain CC-AMO-30B(T) as a representative of a novel species within the genus Sphingomicrobium for which the name Sphingomicrobium astaxanthinifaciens sp. nov. is proposed; the type strain is CC-AMO-30B(T) ( =JCM 18551(T) =BCRC 80465(T)).

Aquibacter zeaxanthinifaciens gen. nov., sp. nov., a zeaxanthin-producing bacterium of the family Flavobacteriaceae isolated from surface seawater, and emended descriptions of the genera Aestuariibaculum and Gaetbulibacter

A Gram-stain-negative, strictly aerobic, rod-shaped, non-flagellated, non-spore-forming and gliding marine bacterium, designated strain CC-AMZ-304(T), was isolated from coastal surface seawater near Taichung harbour, Taiwan. Strain CC-AMZ-304(T) predominantly synthesized zeaxanthin and thus formed yellow colonies on marine agar. The novel strain showed an unstable phylogenetic position, although sharing high pairwise 16S rRNA gene sequence similarities of 95.9-94.9, 95.7 and 95.1-93.9 % with Gaetbulibacter species (n = 4), Aestuariibaculum suncheonense SC17(T) and Bizionia species (n = 7), respectively. The polar lipid profile of strain CC-AMZ-304(T) consisted of phosphatidylethanolamine, five unidentified lipids, one unidentified phospholipid, two unidentified aminolipids and one unidentified glycolipid. The major (>5 % of the total) fatty acids were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 0 3-OH, iso-C15 : 0 3-OH and C15 : 1ω5c. The DNA G+C content was 36.0 mol%. Menaquinone-6 (MK-6) was the sole respiratory quinone and the major polyamine was triamine sym-homospermidine. Phylogenetic distinctiveness, unique polar lipid composition, presence of significant amounts of branched hydroxyl fatty acids (iso-C17 : 0 3-OH and iso-C15 : 0 3-OH) and a low amount of anteiso-C15 : 0, and several additional distinguishing biochemical features clearly discriminated strain CC-AMZ-304(T) from the type species of the genera Aestuariibaculum and Gaetbulibacter. Thus, based on data from the present polyphasic study, strain CC-AMZ-304(T) is considered to represent a novel species of a new genus within the family Flavobacteriaceae, for which the name Aquibacter zeaxanthinifaciens gen. nov., sp. nov. is proposed; the type strain of Aquibacter zeaxanthinifaciens is CC-AMZ-304(T) ( = JCM 18557(T) = BCRC 80463(T)). Emended descriptions of the genera Aestuariibaculum and Gaetbulibacter are also proposed.

Azospirillum fermentarium sp. nov., a nitrogen-fixing species isolated from a fermenter.

An aerobic, Gram-stain-negative, spiral or rod-shaped, non-spore-forming, diazotrophic bacterium (strain CC-LY743(T)) was isolated from a fermentative tank in Taiwan. Strain CC-LY743(T) was able to grow at 20-37 °C and pH 6.0-8.0 and tolerated up to 3.0 % (w/v) NaCl. It was positive for nitrogen fixation, with activity of 10.6 nmol ethylene h(-1). 16S rRNA gene sequence analysis of strain CC-LY743(T) showed highest similarity to Azospirillum picis DSM 19922(T) (96.1 %), Azospirillum oryzae JCM 21588(T) (96.0 %) and Azospirillum rugosum DSM 19657(T) (96.0 %) and lower similarity (<96.0 %) to all other Azospirillum species. Highest nifH gene sequence similarities were obtained with Azospirillum brasilense BCRC 12270(T) (92.0 %), Azospirillum formosense BCRC 80273(T) (92.3 %) and A. rugosum DSM 19657(T) (91.8 %). It was positive in the rapid identification by a genus-specific primer set. The predominant quinone system was ubiquinone 10 (Q-10) and the DNA G+C content was 69.6±0.1 mol%. The major fatty acids found in strain CC-LY743(T) were n-C16 : 0, C19 : 0 cyclo ω8c, C14 : 0 3-OH/C16 : 1 iso I, C16 : 1ω7c/C16 : 1ω6c and C18 : 1ω7c/C18 : 1ω6c. Based on its phylogenetic, phenotypic and chemotaxonomic features, strain CC-LY743(T) is considered to represent a novel species within the genus Azospirillum for which the name Azospirillum fermentarium sp. nov. is proposed. The type strain is CC-LY743(T) ( = BCRC 80505(T) = JCM 18688(T) = LMG 27264(T)).

Muricauda lutaonensis sp. nov., a moderate thermophile isolated from a coastal hot spring

A yellow-pigmented, Gram-staining-negative, aerobic, non-motile, moderately thermophilic, rod-shaped bacterium, designated strain CC-HSB-11(T), was isolated from a coastal hot spring of Green Island (Lutao), located off Taituang, Taiwan. 16S rRNA gene sequence analysis demonstrated that it shared <94.4 % sequence similarity with Muricauda species. Menaquinone with six isoprene units (MK-6) was the major respiratory quinone and iso-C(15 : 0), iso-C(15 : 1) G, iso-C(15 : 0) 3-OH, iso-C(16 : 0) 3-OH, iso-C(17 : 0) 3-OH and summed feature 3 (comprising iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c/t) were the predominant fatty acids. The predominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Six unidentified phospholipids and glycolipids also occurred as minor components. The DNA G+C content of strain CC-HSB-11(T) was 46.4+/-1 mol%. On the basis of 16S rRNA gene sequence similarities with other Muricauda species and differentiating fatty acid compositions and other phenotypic data, strain CC-HSB-11(T) represents a novel species in the genus Muricauda, for which the name Muricauda lutaonensis sp. nov. is proposed. The type strain is CC-HSB-11(T) (=BCRC 17850(T) =KCTC 22339(T)).

Lutaonella thermophila gen. nov., sp. nov., a moderately thermophilic member of the family Flavobacteriaceae isolated from a coastal hot spring

A yellow-pigmented, Gram-staining-negative, aerobic, non-motile, moderately thermophilic, rod-shaped bacterium, CC-MHSW-2T, was isolated from a coastal hot spring of Green Island (Lutao), located off Taituang, Taiwan. The 16S rRNA gene sequence analysis demonstrated that it shared <93.2% sequence similarity with Aquimarina species. The organism was unable to produce acid from carbohydrates, but it could utilize a number of organic acids and amino acids. Menaquinone 6 (MK-6) was the major respiratory quinone and iso-C15:0, iso-C17:0 3-OH and summed feature 3 (comprising C16:1omega7c and/or C16:1omega6c) were the predominant fatty acids. This fatty acid profile distinguished the isolate from members of the genera Aquimarina, Tamlana, Zhouia, Leeuwenhoekiella and Cellulophaga. The DNA G+C content of strain CC-MHSW-2T was 39.7+/-1 mol%. On the basis of the 16S rRNA gene sequence analysis and the chemotaxonomic and physiological data, strain CC-MHSW-2T represents a novel genus and species in the family Flavobacteriaceae, for which the name Lutaonella thermophila gen. nov., sp. nov. is proposed. The type strain is CC-MHSW-2T (=KCTC 22538T=JCM 15069T).