Effect of seed biopriming with selected endophytes on the growth and chilling tolerance of rice plants.

The aim of this study was to develop an efficient bioinoculant for amelioration of adverse effects from chilling stress (10°C), which are frequently occurred during rice seedling stage. Seed germination bioassay under chilling condition with rice (Oryza sativa L.) cv. Tainan 11 was performed to screen for plant growth-promoting (PGP) bacteria among 41 chilling-tolerant rice endophytes. And several agronomic traits were used to evaluate the effects of bacterial inoculation on rice seedling, which were experienced for 7-d chilling stress in walk-in growth chamber. The field trials were further used to verify the performance of potential PGP endophytes on rice growth. A total of three endophytes with multiple PGP traits were obtained. It was demonstrated that Pseudomonas sp. CC-LS37 inoculation led to 18% increase of maximal efficiency of Photosystem II (PSII) after 7-d chilling stress and 7% increase of chlorophyll a content, and 64% decline of malondialdehyde content in shoot after 10-d recovery at normal temperature in walk-in growth chamber. In field trial, biopriming of seeds with strain CC-LS37 caused rice plants to increase shoot chlorophyll soil plant analysis development values (by 2.9% and 2.5%, respectively) and tiller number (both by 61%) under natural climate and chilling stress during the end of tillering stage, afterward 30% more grain yield was achieved. In conclusion, strain CC-LS37 exerted its function in increase of tiller number of chilling stress-treated rice seedlings via improvement of photosynthetic characteristics, which in turn increases the rice grain yield. This study also proposed multiple indices used in the screening of potential endophytes for conferring chilling tolerance of rice plants.

Leucobacter zeae sp. nov., isolated from the rhizosphere of maize (Zea mays L.).

A novel yellow-pigmented, aerobic, rod-shaped, non-motile bacterium, designated strain CCMF41T, was isolated from rhizosphere soil of maize (Zea mays) collected in Wufeng District, Taichung, Taiwan. Strain CC-MF41T exhibited 16S rRNA gene sequence similarity of 97.5, 97.3, 97.2 and 97.1% to Leucobacter chironomi MM2LBT (and 'Leucobacter kyeonggiensis'F3-P9 and 'L. humi' Re-6, the names of which have not been validly published), Leucobactertardus K70/01T, L. komagatae IFO 15245T and 'Leucobacter margaritiformis' A23. However,CC-MF41T and 'L. margaritiformis' A23 formed a loosely bound phylogenetic lineage (with alow bootstrap value) associated with species of the genus Leucobacter. In DNA­DNA reassociation experiments, the relatedness of strain CC-MF41T to L. chironomi DSM 19883T was 57.1% (reciprocal value 29.1 %). The DNA G+C content of strain CC-MF41T was 72.1 mol% and the cell-wall peptidoglycan contained 2,4-diaminobutyric acid, alanine, glycine,glutamic acid and threonine. The major menaquinone was MK-11 and the predominant fatty acids were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. The polar lipid profile of strain CCMF41T contained major amounts of diphosphatidylglycerol followed by an unidentified glycolipid, phosphatidylglycerol and an unknown phospholipid. Based on its phylogenetic,phenotypic and chemotaxonomic distinctiveness, strain CC-MF41T represents a novel species of Leucobacter, for which the name Leucobacter zeae sp. nov. is proposed. The type strain isCC-MF41T (=BCRC 80515T=LMG 27265T).

Azospirillum soli sp. nov., a nitrogen-fixing species isolated from agricultural soil.

An aerobic, Gram-stain-negative, rod or spiral-shaped diazotrophic bacterium (designated strain CC-LY788T), was isolated from agricultural soil in Taiwan. Strain CC-LY788T was able to grow at 25-40 °C, pH 6.0-8.0 and tolerated NaCl to 2.0% (w/v). Positive for nitrogen fixation with the activity recorded as 6.5 nmol ethylene h(-1). Strain CC-LY788T showed highest 16S rRNA gene sequence similarity to Azospirillum picis DSM 19922T (97.2%) and Azospirillum rugosum DSM 19657T (97.1%) and lower sequence similarities (<96.6%) to all other species of the genus Azospirillum. According to the DNA-DNA hybridization, the relatedness values of strain CC-LY788T with A. picis DSM 19922T and A. rugosum DSM 19657T were 51.1±5.5% and 46.8±2.1%, respectively. Strain CC-LY788T was positive for the rapid identification of the genus-specific primer set. The respiratory quinone system was ubiquinone (Q-10) and the DNAG+C content was 69.8 mol%. The major fatty acids found in strain CC-LY788T were C16 : 0, C18 : 1 2-OH, C14 : 0 3-OH/C16 : 1 iso I (summed feature 2), C16 : 1ω7c/C16 : 1ω6c (summed feature 3), C18 : 0 ante/C18 : 2ω6,9c (summed feature 5) and C18 : 1ω7c/C18 : 1ω6c (summed feature 8). Based on the phylogenetic, phenotypic and chemotaxonomic features, strain CC-LY788T represents a novel species of the genus Azospirillum, for which the name Azospirillum soli sp. nov. is proposed. The type strain is CC-LY788T (=BCRC 80569T=JCM 18820T).

Paenibacillus medicaginis sp. nov. a chitinolytic endophyte isolated from a root nodule of alfalfa (Medicago sativa L.).

A Gram-stain-variable, short-rod-shaped, endospore-forming, strictly aerobic, non-motile, chitinolytic and endophytic bacterium, designated strain CC-Alfalfa-19T, exhibiting unusual bipolar appendages was isolated from a root nodule of alfalfa (Medicago sativa L.) in Taiwan and subjected to a polyphasic taxonomic study. Based on 16S rRNA gene sequence analysis, strain CC-Alfalfa-19T was found to be most closely related to Paenibacillus puldeungensis CAU 9324T (95.2 %), whereas other species of the genus Paenibacillus shared ≤ 95.0 % sequence similarity. The phylogenetic analysis revealed a distinct phyletic lineage established by strain CC-Alfalfa-19T with respect to other species of the genus Paenibacillus. Fatty acids comprised predominantly anteiso-C15 : 0, C16 : 0, anteiso-C17 : 0 and iso-C16 : 0. Menaquinone 7 (MK-7) was identified as the sole respiratory quinone and the genomic DNA G+C content was 42.7 mol%. Polar lipids included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, an unidentified glycolipid and an unidentified lipid. The diagnostic diamino acid found in the cell-wall peptidoglycan was meso-diaminopimelic acid. Based on the polyphasic taxonomic evidence that was in line with the genus Paenibacillus and additional distinguishing characteristics, strain CC-Alfalfa-19T is considered to represent a novel species, for which the name Paenibacillus medicaginis sp. nov. (type strain CC-Alfalfa-19T = BCRC 80441T = JCM 18446T) is proposed.

Chryseobacterium echinoideorum sp. nov., isolated from sea urchins (Tripneustes gratilla).

A Gram-stain-negative, aerobic, non-motile, rod-shaped, flexirubin-producing bacterium, designated strain CC-CZW010T, was isolated from the edible sea urchin Tripneustes gratilla in Penghu Island, Taiwan. The isolate grew optimally at pH 7.0 and 30 °C in the presence of 2 % (w/v) NaCl. The most closely related strains in terms of 16S rRNA gene sequence similarity were Chryseobacterium taihuense NBRC 108747T (97.6 %) and Chryseobacterium aquaticum KCTC 12483T (96.7 %). Phylogenetic analyses based on 16S rRNA gene sequences revealed a distinct taxonomic position attained by strain CC-CZW010T with respect to other species of the genus Chryseobacterium. Strain CC-CZW010T possessed iso-C15 : 0, anteiso-C15 : 0, iso-C17 :  0 3-OH, summed feature 3 (comprising C16 : 1ω7c/C16 : 1ω6c) and summed feature 9 (comprising C16 :  0 10-methyl/iso-C17 : 1ω9c) as predominant fatty acids. The major polar lipid profile consisted of phosphatidylethanolamine, two unidentified lipids and five aminolipids. The polyamine pattern contained the major compound sym-homospermidine. Menaquinone 6 (MK-6) was the predominant respiratory quinone, and the G+C content of the genomic DNA was 36.4 mol%. According to distinct phylogenetic, phenotypic and chemotaxonomic features, strain CC-CZW010T represents a novel species of the genus Chryseobacterium, for which the name Chryseobacterium echinoideorum sp. nov. is proposed. The type strain is CC-CZW010T ( = BCRC 80786T = JCM 30470T).

Vitellibacter echinoideorum sp. nov., isolated from a sea urchin (Tripneustes gratilla).

A Gram-stain-negative, aerobic, rod-shaped, yellow-pigment-producing bacterium (designated strain CC-CZW007(T)) was isolated from seafood samples (sea urchins) at Penghu Island in Taiwan. Strain CC-CZW007(T) grew optimally at pH 7.0 and 30 °C in the presence of 3% (w/v) NaCl. The novel strain shared highest 16S rRNA gene sequence similarity to Vitellibacter vladivostokensis JCM 11732(T) (96.8%), Vitellibacter soesokkakensis KCTC 32536(T) (96.4%), Vitellibacter nionensis KCTC 32420(T) (95.8%) and Vitellibacter aestuarii JCM 15496(T) (95.6%) and lower sequence similarity to members of other genera. Phylogenetic analyses based on 16S rRNA genes revealed a distinct taxonomic position attained by strain CC-CZW007(T) with respect to other species of the genus Vitellibacter. The major fatty acids were iso-C15 : 0 and iso-C17 : 0 3-OH. The polar lipid profile was composed of major amounts of phosphatidylethanolamine, unidentified lipids and aminolipids; a moderate amount of aminophospholipid was also detected. The DNA G + C content was 34.7 mol%. The predominant quinone system was menaquinone (MK-6). On the basis of polyphasic taxonomic evidence presented here, strain CC-CZW007(T) is proposed to represent a novel species within the genus Vitellibacter, for which the name Vitellibacter echinoideorum sp. nov. is proposed. The type strain is CC-CZW007(T) ( = BCRC 80886(T) = JCM 30378(T)).

Nocardioides echinoideorum sp. nov., isolated from sea urchins (Tripneustes gratilla).

A Gram-stain-positive, aerobic, non-motile, rod-shaped, yellow-pigment-producing bacterium, (designated strain CC-CZW004T), was isolated from seafood samples (sea urchins) at Penghu Island in Taiwan. Strain CC-CZW004T grew optimally at pH 7.0 and 30 °C in the presence of 3 % (w/v) NaCl. Phylogenetic analyses based on 16S rRNA genes revealed a distinct taxonomic position attained by strain CC-CZW004T with respect to other members of the genus Nocardioides. The novel strain shared highest 16S rRNA gene sequence similarities to Nocardioides daejeonensis JCM 16922T (96.4 %), Nocardioides pacificus JCM 19260T (96.3 %), and Marmoricola scoriae JCM 17444T (96.2 %). The major fatty acids of strain CC-CZW004T consisted of C17:0, C16:1ω5c, C17:1ω8c`, iso-C16:0 and C19:1ω11c/C19:1ω9c (summed feature 6). The diagnostic diamino acid in the cell wall was ll-2,6-diaminopimelic acid. The polar lipid profile was composed of major amounts of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and aminophospholipid. The DNA G+C content was 73.3 mol%. The predominant quinone system was menaquinone (MK-8). On the basis of polyphasic taxonomic evidences presented here, strain CC-CZW004T represents a novel species of the genus Nocardioides, for which the name Nocardioides echinoideorum sp. nov. is proposed. The type strain is CC-CZW004T ( = BCRC 16974T = JCM 30276T).

Description of Niveispirillum fermenti gen. nov., sp. nov., isolated from a fermentor in Taiwan, transfer of Azospirillum irakense (1989) as Niveispirillum irakense comb. nov., and reclassification of Azospirillum amazonense (1983) as Nitrospirillum amazonense gen. nov.

A taxonomic study was carried out on a novel aerobic bacterial strain (designated CC-LY736(T)) isolated from a fermentor in Taiwan. Cells of strain CC-LY736(T) were Gram-stain negative, spiral-shaped and motile by means of a monopolar flagellum. Strain CC-LY736(T) shared the greatest degree of 16S rRNA gene sequence similarity to Azospirillum irakense DSM 11586(T) (97.2 %), Rhodocista centenaria JCM 21060(T) (96.3 %) and Rhodocista pekingensis JCM 11669(T) (96.1 %). The major fatty acids were C16:0, C16:1 ω5c, C19:0 cyclo ω8c, C18:1 ω7c/C18:1 ω6c, C16:0 3-OH and C18:1 2-OH. The predominant polar lipids included phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidyldimethylethanolamine and two unidentified glycolipids. The common major respiratory quinone was ubiquinone Q-10 and predominant polyamines were sym-homospermidine and putrescine. The DNA G+C content of strain CC-LY736(T) was 67.6 ± 0.1 mol %. During phylogenetic analysis, strain CC-LY736(T) formed a unique phyletic lineage associated with Rhodocista species. However, the combination of genetic, chemotaxonomic and physiological data clearly indicated that strain CC-LY736(T) was a novel representative of the family Rhodospirillaceae. Based on the polyphasic comparison, the name Niveispirillum fermenti gen. nov., sp. nov. is proposed; the type strain of the type species is CC-LY736(T) (= BCRC 80504(T) = LMG 27263(T)). In addition, the reclassifications of Azospirillum irakense as Niveispirillum irakense comb. nov. (type strain KBC1(T) = ATCC 51182(T) = BCRC 15764(T) = CIP 103311(T)), and Azospirillum amazonense as Nitrospirillum amazonense gen. nov., sp. nov. (type strain Am14(T) = ATCC 35119(T) = BCRC 14279(T) = DSM 3787(T)) are proposed based on the polyphasic taxonomic data obtained in this study.

Comprehensive insights into the impact of bacterial indole-3-acetic acid on sensory preferences in Drosophila melanogaster.

Several bacteria of environmental and clinical origins, including some human-associated strains secrete a cross-kingdom signaling molecule indole-3-acetic acid (IAA). IAA is a tryptophan (trp) derivative mainly known for regulating plant growth and development as a hormone. However, the nutritional sources that boost IAA secretion in bacteria and the impact of secreted IAA on non-plant eukaryotic hosts remained less explored. Here, we demonstrate significant trp-dependent IAA production in Pseudomonas juntendi NEEL19 when provided with ethanol as a carbon source in liquid cultures. IAA was further characterized to modulate the odor discrimination, motility and survivability in Drosophila melanogaster. A detailed analysis of IAA-fed fly brain proteome using high-resolution mass spectrometry showed significant (fold change, ± 2; p ≤ 0.05) alteration in the proteins governing neuromuscular features, audio-visual perception and energy metabolism as compared to IAA-unfed controls. Sex-wise variations in differentially regulated proteins were witnessed despite having similar visible changes in chemo perception and psychomotor responses in IAA-fed flies. This study not only revealed ethanol-specific enhancement in trp-dependent IAA production in P. juntendi, but also showed marked behavioral alterations in flies for which variations in an array of proteins governing odor discrimination, psychomotor responses, and energy metabolism are held responsible. Our study provided novel insights into disruptive attributes of bacterial IAA that can potentially influence the eukaryotic gut-brain axis having broad environmental and clinical implications.

Pseudomonas sagittaria sp. nov., a siderophore-producing bacterium isolated from oil-contaminated soil.

An aerobic, Gram-stain-negative, rod-shaped bacterium with a single polar flagellum, designated CC-OPY-1(T), was isolated from an oil-contaminated site in Taiwan. CC-OPY-1(T) produces siderophores, and can grow at temperatures of 25-37 °C and pH 5.0-9.0 and tolerate <5 % (w/v) NaCl. The 16S rRNA gene sequence analysis of CC-OPY-1(T) showed high pairwise sequence similarity to Pseudomonas alcaligenes BCRC 11893(T) (97.1 %), Pseudomonas. alcaliphila DSM 17744(T) (97.1 %), Pseudomonas tuomuerensis JCM 14085(T) (97.1 %), Pseudomonas toyotomiensis JCM 15604(T) (96.9 %) and lower sequence similarity to remaining species of the genus Pseudomonas. The phylogenetic trees reconstructed based on gyrB and rpoB gene sequences supported the classification of CC-OPY-1(T) as a novel member of the genus Pseudomonas. The predominant quinone system of strain CC-OPY-1T was ubiquinone (Q-9) and the DNA G+C content was 68.4 ± 0.3 mol%. The major fatty acids were C12 : 0, C16 : 0, C17 : 0 cyclo and summed features 3 and 8 consisting of C16 : 1ω7c/C16 : 1ω6c and C18 : 1ω7c/C18 : 1ω6c, respectively. The major polar lipids were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylcholine (PC) and two unknown phospholipids (PL1-2). Due to distinct phylogenetic, phenotypic and chemotaxonomic features, CC-OPY-1(T) is proposed to represent a novel species within the genus Pseudomonas for which the name Pseudomonas sagittaria sp. nov. is proposed. The type strain is CC-OPY-1(T) ( = BCRC 80399(T) = JCM 18195(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)).

Pseudomonas guguanensis sp. nov., a gammaproteobacterium isolated from a hot spring.

An aerobic, Gram-stain-negative, rod-shaped bacterium (designated strain CC-G9A(T)), motile by a polar-flagellum, was isolated from a hot spring water sample in Taiwan. Strain CC-G9A(T) could grow at 20-42 °C, pH 6.0-10.0 and tolerate up to 7% (w/v) NaCl. The 16S rRNA gene sequence analysis of strain CC-G9A(T) showed pairwise sequence similarity to Pseudomonas mendocina LMG 1223(T) (97.7%), Pseudomonas alcaligenes ATCC 14909(T) (97.8 %), Pseudomonas alcaliphila DSM 17744(T) (97.8 %), Pseudomonas toyotomiensis JCM 15604(T) (97.6 %), Pseudomonas oleovorans subsp. lubricantis DSM 21016(T) (97.6 %) and Pseudomonas argentinensis BCRC 17807(T) (97.5 %), and lower sequence similarity to other species of the genus Pseudomonas. According to DNA-DNA association analysis, the relatedness of strain CC-G9A(T) to P. mendocina BCRC 10458(T), P. alcaliphila DSM 17744(T), P. alcaligenes BCRC 11893(T), P. oleovorans subsp. lubricantis DSM 21016(T), P. argentinensis BCRC 17807(T) and P. oleovorans subsp. oleovorans BCRC 11902 was 55.1±3.1, 13.7±1.5, 14.1±1.8, 58.5±1.1, 28.9±2.0 and 28.6±1.8 %, respectively. The evolutionary trees reconstructed based on 16S rRNA, gyrB and rpoB gene sequences revealed varying phylogenetic neighbourhoods of strain CC-G9A(T) with regard to the most closely related type strains. The predominant quinone system was ubiquinone (Q-9) and the DNA G+C content was 64.3±1.3 mol%. The major fatty acids were C10 : 0 3-OH, C12 : 0, C12 : 0 3-OH, C16 : 0 and summed features 3 and 8 consisting of C16 : 1ω7c/C16 : 1ω6c and C18 : 1ω7c/C18 : 1ω6c, respectively. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol. According to distinct phylogenetic, phenotypic and chemotaxonomic features, strain CC-G9A(T) is proposed to represent a novel species within the genus Pseudomonas for which the name Pseudomonas guguanensis sp. nov. is proposed. The type strain is CC-G9A(T) ( = BCRC 80438(T) = JCM 18416(T)).

Chiayiivirga flava gen. nov., sp. nov., a novel bacterium of the family Xanthomonadaceae isolated from an agricultural soil, and emended description of the genus Dokdonella.

A novel Gram-reaction-negative, yellow-pigmented, aerobic, non-motile and rod-shaped bacterium designated strain CC-YHH031(T) was isolated from an agricultural soil collected at Chiayi County, Taiwan. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain CC-YHH031(T) formed a discrete monophyletic lineage in the family Xanthomonadaceae, sharing high pairwise sequence similarity of 93.5-95.2 and 94.8% with species of the genus Dokdonella (94.9% similarity to the type strain of the type species) and Aquimonas voraii GPTSA 20(T), respectively. The genomic DNA G+C content of strain CC-YHH031(T) was 68.6 ± 0.7 mol% and the predominant respiratory quinone was ubiquinone Q-8. Spermidine was the principal polyamine, with minor amounts of putrescine. Major fatty acids (>5% of total fatty acids) were iso-C(16:00, iso-C(15:0), C(16:1)ω7c and/or C(16:1)ω6c (summed feature 3), iso-C(17:1)ω9c, iso-C(14:0), iso-C(11:0) and iso-C(11:0) 3-OH. The polar lipid profile of strain CC-YHH031(T) included phosphatidylethanolamine, phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, two unidentified aminophospholipids (APL1-2) and four unidentified phospholipids (PL1-4). Strain CC-YHH031(T) was distinguished particularly from the type species of the genus Dokdonella (Dokdonella koreensis) by the presence of major amounts of iso-C(14:0) and summed feature 3 and minor amounts of iso-C(17:0) and by the complete absence of anteiso-C(17:0), the presence of PL1-3 and APL1-2, the absence of APL3 and the presence of putrescine in the former. On the basis of distinguishing genotypic and phenotypic evidence, strain CC-YHH031(T) is proposed to represent a novel genus and species within the family Xanthomonadaceae, for which the name Chiayiivirga flava gen. nov., sp. nov. is proposed. The type strain of Chiayiivirga flava is CC-YHH031(T) ( =BCRC 80274(T) =DSM 24163(T)).

Aureimonas ferruginea sp. nov. and Aureimonas rubiginis sp. nov., two siderophore-producing bacteria isolated from rusty iron plates.

Two novel siderophore-producing strains designated CC-CFT023(T) and CC-CFT034(T), isolated from a rusty iron plate, are characterized in this study. Cells of both strains were catalase- and oxidase-positive. Strain CC-CFT023(T) showed a high pairwise 16S rRNA gene sequence similarity to Aureimonas altamirensis LMG 23375(T) (96.0 %), whereas, strain CC-CFT034(T) shared a maximum similarity to Aureimonas ureilytica DSM 18598(T) (95.8 %). The predominant quinone system was ubiquinone (Q-10) and the DNA G+C contents of CC-CFT023(T) and CC-CFT034(T) were 69.5 mol% and 67.7 mol%, respectively. The major fatty acids of these strains were C16 : 0, C18 : 0, C19 : 0 cyclo ω8c, C18 : 1 2-OH and summed features 3 and 8, consisting of C16 : 1ω7c/C16 : 1ω6c and C18 : 1ω7c/C18 : 1ω6c, respectively. Polar lipid profiles of both of these isolates include diphosphatidylglycerol (DPG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG) and most importantly sulfoquinovosyldiacylglycerol (SQDG), which is one of the typical molecular features reported to delineate the members of the genus Aureimonas from their closest relatives, species of the genus Aurantimonas. Based on the phylogenetic, phenotypic and chemotaxonomic features, strains CC-CFT023(T) and CC-CFT034(T) represent two novel species within the genus Aureimonas, for which the names Aureimonas ferruginea sp. nov. (type strain CC-CFT023(T) = BCRC 80439(T) = JCM 18444(T)) and Aureimonas rubiginis sp. nov. (type strain CC-CFT034(T) = BCRC 80440(T) = JCM 18445(T)) are proposed.

Co-exposure of dimethomorph and imidacloprid: effects on soil bacterial communities in vineyard soil.

In Taiwan, the pesticides dimethomorph and imidacloprid are recommended for pest control in vineyards. Therefore, tank-mixing of these two pesticides is usually a routine practice before application. This study analyzed the influence of vineyard soil microbial flora under the recommended and high dosages (100 times the recommended dosage) of dimethomorph and imidacloprid. Individual and combined applications of pesticides were also tested through batches of soil incubation experiments. Four treatments-control (C), dimethomorph (DT), imidacloprid (IM), and mixed application of dimethomorph and imidacloprid (ID)-were used in the experimental design. From the soil metabolism, no significant reaction was observed after 2 months in the recommended dosage group, regardless of whether the pesticides were being applied individually or combined. For the high dosage, imidacloprid showed a higher effect than the co-exposure treatments, showing a possible prolonged effect after its repetitive application. From PCoA analysis, pesticide treatments altered the soil ecology after 2 months, and the effect of imidacloprid can be explicitly observed at high dosages. At the phylum level, Acidobacteria can indicate pesticide application around the recommended dosage. It was inhibited by ID on day 7 and was augmented by all pesticides on day 63. The effect of the recommended dosage of pesticide mixtures after 2 months of incubation was revealed in the minor families Gemmataceae and Pirellulaceae, while the high dosage treatments affected both the core and the minor families. Our findings verified the changes in the composition of microbial communities upon pesticide application, which would affect carbon, nitrogen, sulfur, phosphorous cycles, and contaminant removal ability within the vineyard.

Azospirillum formosense sp. nov., a diazotroph from agricultural soil.

A gram-negative, spiral or rod-shaped, non-spore-forming diazotrophic bacterium, designated CC-Nfb-7(T), was isolated from agricultural soil in Yunlin County, Taiwan. 16S rRNA gene sequence analysis showed that strain CC-Nfb-7(T) was most closely related to Azospirillum brasilense DSM 1690(T) (97.4 % 16S rRNA gene sequence similarity), Azospirillum rugosum IMMIB AFH-6(T) (96.8 %) and Azospirillum oryzae JCM 21588(T) (96.6 %); <96.5 % 16S rRNA gene sequence similarity was found with all other members of the genus Azospirillum. DNA-DNA relatedness between strain CC-Nfb-7(T) and A. brasilense DSM 1690(T), A. rugosum DSM 19657(T) and A. oryzae JCM 21588(T) was 38.9, 30.1 and 31.8 %, respectively. The respiratory quinone was ubiquinone Q-10. The major fatty acids were summed feature 8 (consisting of C(18 : 1)ω7c and/or C(18 : 1)ω6c), summed feature 3 (consisting of C(16 : 1)ω7c and/or C(16 : 1)ω6c), summed feature 2 (consisting of C(14 : 0) 3-OH and/or iso-C(16 : 1) I), C(16 : 0), C(18 : 0) 2-OH and C(16 : 0) 3-OH. The polar lipids consisted mainly of phosphatidylglycerol, phosphatidylcholine and one unidentified phospholipid. Furthermore, moderate amounts of phosphatidylethanolamine, phosphatidyldimethylethanolamine and one unidentified aminophospholipid were also detected. Strain CC-Nfb-7(T) could be distinguished from members of phylogenetically related species by differences in phenotypic properties. On the basis of morphological, chemotaxonomic and phylogenetic data, strain CC-Nfb-7(T) represents a novel species within the genus Azospirillum, for which we propose the name Azospirillum formosense sp. nov. The type strain is CC-Nfb-7(T) ( = BCRC 80273(T) = JCM 17639(T) = DSM 24137(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)).

Gordonia humi sp. nov., isolated from soil.

A Gram-stain-positive, non-endospore-forming actinobacterium (CC-12301(T)) was isolated from soil attached to a spawn used in the laboratory to grow the edible mushroom Agaricus brasiliensis. Based on 16S rRNA gene sequence similarities, strain CC-12301(T) was shown to belong to the genus Gordonia and was most closely related to the type strains of Gordonia hydrophobica (97.6 % similarity), Gordonia terrae (97.5 %), Gordonia amarae (97.5 %) and Gordonia malaquae (97.4 %). The quinone system was determined to consist predominantly of menaquinone MK-9(H(2)), minor amounts of MK-8(H(2)) and MK-7(H(2)). The polar lipid profile consisted of the major compounds diphosphatidylglycerol and phosphatidylethanolamine, moderate amounts of two phosphatidylinositol mannosides and phosphatidylinositol and minor amounts of phosphatidylglycerol, three unidentified glycolipids, two phosphoglycolipids and a phospholipid. Mycolic acids were present. These chemotaxonomic traits and the major fatty acids, which were C(16 : 1) cis9, C(16 : 0), C(18 : 1) and tuberculostearic acid (10-methyl C(18 : 0)), supported the affiliation of strain CC-12301(T) to the genus Gordonia. The results of physiological and biochemical tests allowed clear phenotypic differentiation of strain CC-12301(T) from the most closely related Gordonia species. Strain CC-12301(T) therefore represents a novel species, for which the name Gordonia humi sp. nov. is proposed, with the type strain CC-12301(T) (=DSM 45298(T) =CCM 7727(T)).

Novosphingobium soli sp. nov., isolated from soil.

A yellow-pigmented, Gram-negative, rod-shaped, non-spore-forming bacterium, strain CC-TPE-1(T), was isolated from oil-contaminated soil near an oil refinery located in Kaohsiung County, Taiwan. 16S rRNA gene sequence analysis of strain CC-TPE-1(T) showed highest sequence similarity to Novosphingobium naphthalenivorans TUT562(T) (98.1 %), N. panipatense SM16(T) (97.9 %) and N. mathurense SM117(T) (97.6 %) and lower (<97 %) sequence similarity to all other Novosphingobium species. DNA-DNA hybridizations of strain CC-TPE-1(T) with N. naphthalenivorans DSM 18518(T), N. panipatense SM16(T) and N. mathurense SM117(T) showed low relatedness of 30 % (reciprocal 35 %), 29.1 % (reciprocal 30.6 %) and 35 % (reciprocal 23.6 %), respectively. The major respiratory quinone was ubiquinone Q-10, the predominant fatty acid was C(18 : 1)ω7c (49.9 %) and three 2-hydroxy fatty acids, C(14 : 0) 2-OH (8.2 %), C(15 : 0) 2-OH (2.45 %) and C(16 : 0) 2-OH (1.05 %), were detected. Polar lipids consisted mainly of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, phosphatidyldimethylethanolamine, two sphingoglycolipids, phosphatidylmonomethylethanolamine and several unidentified lipids, and a yellow pigment was also detected. The polyamine pattern contained the single major compound spermidine. Characterization by 16S rRNA gene sequence analysis, physiological parameters, pigment analysis and polyamine, ubiquinone, polar lipid and fatty acid compositions revealed that strain CC-TPE-1(T) represents a novel species of the genus Novosphingobium, for which we propose the name Novosphingobium soli sp. nov., with the type strain CC-TPE-1(T) (=DSM 22821(T) =CCM 7706(T) =CCUG 58493(T)).