Fo-Ting Shen

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).

Algoriphagus olei sp. nov., isolated from oil-contaminated soil

A motile, Gram-negative, pinkish red-pigmented bacterium (strain CC-Hsuan-617(T)) was isolated from an oil-contaminated soil near an oil refinery located in Kaohsiung County, Taiwan. 16S rRNA gene sequence analysis showed that strain CC-Hsuan-617(T) clustered with Algoriphagus mannitolivorans (97.5 % sequence similarity), Algoriphagus aquatilis (98.0 %) and Algoriphagus boritolerans (97.5 %), followed by Algoriphagus ornithinivorans (97.1 %) and Algoriphagus alkaliphilus (97.1 %). The fatty acid profile of the novel strain was slightly different from those reported for recognized Algoriphagus species. The quinone system contained menaquinone MK-7 as the predominant component. The major polar lipids were phosphatidylethanolamine, an unknown polar lipid, an unknown phospholipid and an unknown aminophospholipid. The main cell polyamine was sym-homospermidine; lesser amounts of spermine and spermidine were also found. The results of DNA-DNA hybridization, and physiological and biochemical tests allowed the genotypic and phenotypic differentiation of strain CC-Hsuan-617(T) from recognized Algoriphagus species. Strain CC-Hsuan-617(T) is thus considered to represent a novel species of the genus Algoriphagus, for which the name Algoriphagus olei sp. nov. is proposed. The type strain is CC-Hsuan-617(T) (=BCRC 17886(T)=CCUG 57471(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)).

Comamonas composti sp nov., isolated from food waste compost

A bacterial strain designated YY287(T), isolated from food waste compost, was investigated by polyphasic taxonomic approach. The cells were rod-shaped, Gram-negative, non-pigmented, non-spore-forming and non-fermentative. Phylogenetic analyses using the 16S rRNA gene sequence showed that the strain formed a monophyletic branch towards the periphery of the evolutionary radiation occupied by the genus Comamonas; its closest neighbours were the type strains Comamonas testosteroni DSM 50244(T) (96.5%), Comamonas terrigena DSM 7099(T) (95.4%), Comamonas odontotermitis Dant 3-8(T) (95.2%) and Comamonas koreensis KCTC 12005(T) (94.6%). Strain YY287(T) was clearly distinguished from all of these strains using phylogenetic analysis, DNA-DNA hybridization, fatty acid composition data and a range of physiological and biochemical characteristics. The major fatty acids were 16:0 (33%), 18:1omega7c (13%) and summed feature 3 (16:1omega7c and/or 15:0 iso 2-OH; 41%). The DNA G+C content of the genomic DNA was 62.8 mol%. It is evident from the genotypic and phenotypic data that strain YY287(T) represents a novel species in the genus Comamonas, for which the name Comamonas composti sp. nov. is proposed. The type strain is YY287(T) (=BCRC 17659(T)=LMG 24008(T)).

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).

Molecular detection and phylogenetic analysis of the alkane 1-monooxygenase gene from Gordonia spp.

The alkB gene encodes for alkane 1-monooxygenase, which is a key enzyme responsible for the initial oxidation of inactivated alkanes. This functional gene can be used as a marker to assess the catabolic potential of bacteria in bioremediation. In the present study, a pair of primers was designed based on the conserved regions of the AlkB amino acid sequences of Actinobacteria, for amplifying the alkB gene from the genus Gordonia (20 Gordonia strains representing 13 species). The amplified alkB genes were then sequenced and analyzed. In the phylogenetic tree based on the translated AlkB amino acid sequences, all the Gordonia segregated clearly from other closely related genera. The sequence identity of the alkB gene in Gordonia ranged from 58.8% to 99.1%, which showed higher sequence variation at the inter-species level compared with other molecular markers, such as the 16S rRNA gene (93.1-99.8%), gyrB gene (77.5-97.3%) or catA gene (72.4-99.5%). The genetic diversity of four selected loci also showed that the alkB gene might have evolved faster than rrn operons, as well as the gyrB or catA genes, in Gordonia. All the available actinobacterial alkB gene sequences derived from the whole genome shotgun sequencing projects are phylogenetically characterized here for the first time, and they exclude the possibility of horizontal gene transfer of the alkB gene in these bacterial groups.

Molecular detection and phylogenetic analysis of the catechol 1,2-dioxygenase gene from Gordonia spp.

The C12O gene (catA gene) encodes for catechol 1,2-dioxygenase, which is a key enzyme involved in the first step catalysis of the aromatic ring in the ortho-cleavage pathway. This functional gene can be used as a marker to assess the catabolic potential of bacteria in bioremediation. C12OF and C12OR primers were designed based on the conserved regions of the CatA amino acid sequence of Actinobacteria for amplifying the catA gene from the genus Gordonia (16 Gordonia representing 11 species). The amplified catA genes (382bp) were sequenced and analyzed. In the phylogenetic tree based on the translated catA amino acid sequences, all the Gordonia segregated clearly from other closely related genera. The sequence similarity of the catA gene in Gordonia ranged from 72.4% to 99.5%, indicating that the catA gene might have evolved faster than rrn operons or the gyrB gene at the inter-species level. A single nucleotide deletion of the catA gene was observed in Gordonia amicalis CC-MJ-2a, Gordonia rhizosphera and Gordonia sputi at nucleotide position 349. This deletion led to an encoding frame shift downstream of 11 amino acid residues, from WPSVAARAPAP to GHPWRPAHLHL, which was similar to most of the non-Gordonia Actinobacteria. Such variations might influence the catabolic activities or substrate utilization patterns of catechol 1,2-dioxygenase among Gordonia.

Parvularcula lutaonensis sp. nov., a moderately thermotolerant marine bacterium isolated from a coastal hot spring

Strain CC-MMS-1(T), a motile, Gram-negative, orange-pigmented bacterium, was isolated from water samples collected from a rare coastal hot spring at Lutao, an island off the eastern coast of Taiwan. 16S rRNA gene sequence studies showed that the novel strain was closely related to Parvularcula bermudensis HTCC2503(T) (95.1 % sequence similarity). The fatty acid profile was slightly different from P. bermudensis HTCC2503(T). The results of physiological and biochemical tests allowed clear phenotypic differentiation of the novel isolate from P. bermudensis HTCC2503(T). It is evident from the genotypic and phenotypic data that the strain should be classified as a novel species in the genus Parvularcula. The name proposed for this taxon is Parvularcula lutaonensis sp. nov. The type strain is CC-MMS-1(T) (=BCRC 17814(T)=KCTC 22245(T)).