Arsenic biotransformation and volatilization in transgenic rice

? Biotransformation of arsenic includes oxidation, reduction, methylation, and conversion to more complex organic arsenicals. Members of the class of arsenite (As(III)) S-adenosylmethyltransferase enzymes catalyze As(III) methylation to a variety of mono-, di-, and trimethylated species, some of which are less toxic than As(III) itself. However, no methyltransferase gene has been identified in plants. ? Here, an arsM gene from the soil bacterium Rhodopseudomonas palustris was expressed in Japonica rice (Oryza sativa) cv Nipponbare, and the transgenic rice produced methylated arsenic species, which were measured by inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS). ? Both monomethylarsenate (MAs(V)) and dimethylarsenate (DMAs(V)) were detected in the roots and shoots of transgenic rice. After 12 d exposure to As(III), the transgenic rice gave off 10-fold greater volatile arsenicals. ? The present study demonstrates that expression of an arsM gene in rice induces arsenic methylation and volatilization, theoretically providing a potential stratagem for phytoremediation.     

<Emphasis Type="Italic">Paenibacillus oryzisoli</Emphasis> sp. nov., isolated from the rhizosphere of rice

A novel bacterium, strain 1ZS3-15^T, was isolated from rhizosphere of rice. Its taxonomic position was investigated using a polyphasic approach. The novel strain was observed to be Gram-stain positive, spore-forming, aerobic, motile and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 1ZS3-15^T was recovered within the genus Paenibacillus. It is closely related to Paenibacillus pectinilyticus KCTC 13222^T (97.9 % similarity), Paenibacillus frigoriresistens CCTCC AB 2011150^T (96.8 %), Paenibacillus alginolyticus JCM 9068^T (96.4 %) and Paenibacillus chondroitinus DSM 5051^T (95.5 %). The fatty acid profile of strain 1ZS3-15^T, which showed a predominance of anteiso-C_15:0 and iso-C_16:0, supported the allocation of the strain into the genus Paenibacillus. The predominant menaquinone was found to be MK-7. The polar lipids profile of strain 1ZS3-15^T was found to consist of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified lipid and two unidentified aminophospholipids. The cell wall peptidoglycan contains meso-diaminopimelic acid. Based on draft genome sequences, the DNA–DNA relatedness between strain 1ZS3-15^T and the closely related species P. pectinilyticus KCTC 13222^T are 24.2 ± 1.0 %, and the Average Nucleotide Identity values between the strains are 78.9 ± 0.1 %, which demonstrated that this isolate represents a new species in the genus Paenibacillus. The DNA G+C content was determined to be 45.3 mol%, which is within the range reported for Paenibacillus species. Characterisation by genotypic, chemotaxonomic and phenotypic analysis indicated that strain 1ZS3-15^T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus oryzisoli sp. nov. is proposed. The type strain is 1ZS3-15^T (= ACCC 19783^T = JCM 30487^T).     

Lysobacter telluris sp. nov., isolated from Korean rhizosphere soil

Archives of Microbiology - A Gram-stain-negative, aerobic, non-motile, non-spore-forming light-yellow-coloured rod-shaped bacterial strain, designated YJ15T, was isolated from soil at Bigeum island...     

Fuscibacter oryzae gen. nov., sp. nov., a phosphate-solubilizing bacterium isolated from the rhizosphere of rice plant

An ovoid to rod shaped, white to brown pigmented, facultative anaerobic, mesophilic, non-phototrophic, Gram-staining-negative, non-motile, multiply by binary fission designated strain KVB23^T, which was isolated from root of rice plant, near Ilsan, South Korea, was investigated for its taxonomic position by polyphasic approach. Optimal growth was found to occur at 30?C, at pH 6.5 and in the absence of NaCl on R2A. Phylogenetic analysis based on the 16S rRNA gene sequence of strain KVB23^T revealed that it formed a distinct lineage, as a separate deep branch within the family Rhodobacteriaceae, with?<?96.5% sequence similarity to representatives of the genera Rhodobacter, Xinfangfangia, Tabrizicola, Falsirhodobacter, Haematobacter, Paenirhodobacter, Pseudorhodobacter and Pararhodobacter. Based in 16S rRNA sequences strain KVB23^T was most closely related to Tabrizicola fusiformis KCTC 62105 ^T (96.5%) and Rhodobacter thermarum KCTC 52712 ^T (96.2%). The draft genome of strain KVB23^T was 3.80 bp long with a DNA G?+?C content of 63.1%. Genome of strain KVB23^T harboured gene clusters for tryptophan and cobalamin biosynthesis. The strain contained Q-10 as the sole respiratory quinone. The predominant fatty acids were found to consist of C_16:0, C_18:0 and summed feature 8 (comprising C_18:1 ω7c and / or C_18:1 ω6). The polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, seven unidentified phosphoglycolipids, two unidentified aminophosphoglycolipid, one unidentified glycolipid and four unidentified lipids. Phosphate-solubilizing bacteria have the ability to dissolve insoluble phosphates and enhance the soil fertility. Strain KVB23^T can solubilize calcium phosphate tribasic. Phosphate solubilizing and tryptophan biosynthesis property of strain KVB23^T could be a possible factor for the increase in growth of rice plant. Differential phenotypic, chemotaxonomic and genotypic properties, together with the phylogenetic distinctiveness, demonstrated that strain KVB23^T was found to represent a novel genus in the Rhodobacteriaceae family, for which the name Fuscibacter oryzae gen. nov., sp. nov. is proposed, with the type strain KVB23^T(=?KACC 21711 ^T?=?NBRC 114716 ^T).

     

Sinomonas notoginsengisoli sp. nov., isolated from the rhizosphere of Panax notoginseng

A Gram-positive, aerobic, non-motile and pale yellow colour actinobacterial strain, designated SYP-B575^T, was isolated from rhizosphere soil of Panax notoginseng. The optimal growth of the strain was found to occur at 28 °C, pH 7.0 and without NaCl. Phylogenetic analysis indicated that strain SYP-B575^T clearly belongs to the genus Sinomonas and should be considered as a candidate of novel species within this genus. The 16S rRNA gene sequence similarities between strain SYP-B575^T and the other Sinomonas type strains ranged from 97.3 to 96.0 %. The predominant isoprenoid quinone was identified as MK-9(H₂) and the major fatty acids were identified as anteiso-C_15:0 and anteiso-C_17:0. The polar lipids were found to consist of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and glycolipids. The major cell-wall amino acids were identified as Lys, Ala, Glu, Gly and Ser. The whole-cell sugars were identified as mannose, ribose, rhamnose, glucose and galactose. The G+C content of the genomic DNA was determined to be 66.6 mol%. The DNA–DNA relatedness values between SYP-B575^T and its closest phylogenetic neighbours were lower than 35.5 %. On the basis of this polyphasic taxonomic study, strain SYP-B575^T represents a novel species of the genus Sinomonas, for which the name Sinomonas notoginsengisoli sp. nov. is proposed. The type strain is SYP-B575^T (=DSM 27685^T = KCTC 29237^T).     

Isoptericola rhizophila sp. nov., a novel actinobacterium isolated from rhizosphere soil

A Gram-positive, yellow pigmented strain, BKS 3-46^T was isolated from a soil sample collected from the rhizosphere of Ficus benghalensis (banyan tree) in Bhitarkanika mangrove forest, in the Indian state of Odisha, and subjected to polyphasic taxonomic study. The 16S rRNA gene sequence of the strain was determined and the sequence analysis showed that strain BKS 3-46^T should be assigned to the genus Isoptericola. The chemotaxonomic data supported this taxonomic placement i.e. presence of menaquinone MK-9(H₄); major fatty acids anteiso C_15:0 and iso-C_15:0; and phosphatidylglycerol, diphosphatidylglycerol and phosphatidylinositol (PI) as major polar lipids. Further phylogenetic analysis of the 16S rRNA gene sequence confirmed that the strain BKS 3-46^T belongs to the genus Isoptericola and is closely related to Isoptericola halotolerans MTCC 11265^T (98.6 %) followed by Isoptericola nanjingensis MTCC 11633^T (98.4 %) and Isoptericola chiayiensis MTCC 11634^T (98.1 %). However, the DNA–DNA hybridization values obtained between strain BKS 3-46^T and other related strains were well below the threshold that is required for the proposal of a novel species. The G+C content of the genomic DNA was determined to be 70.4 mol%. The phenotypic and genotypic data showed that the strain BKS 3-46^T merits the recognition as a representative of a novel species of the genus Isoptericola. It is proposed that the isolate should be classified in the genus Isoptericola as a novel species, Isoptericola rhizophila sp. nov. The type strain is BKS 3-46^T (=MTCC 11080^T=JCM 19252^T).     

Genome sequence of Streptomyces sp. strain TOR3209, a rhizosphere microecology regulator isolated from tomato rhizosphere

Streptomyces sp. strain TOR3209, isolated from tomato rhizosphere, can regulate the rhizosphere microecology of a variety of crops. Strain TOR3209 could improve plant systemic resistance and promote plant growth. Here, the genome sequence of strain TOR3209 is reported, providing the molecular biological basis of the regulation mechanism of rhizosphere microecology.     

Paenibacillus quercus sp. nov., isolated from rhizosphere of Quercus aliena var. acuteserrata

A Gram-positive, spore-forming, rod-shaped and motile bacterium, designated strain 1-25^T, was isolated from the rhizosphere of Quercus aliena var. acuteserrata in Taibai Mountain, Shaanxi Province, China. 16S rRNA gene sequence analysis showed that strain 1-25^T belongs to the genus Paenibacillus. Strain 1-25^T was found to be closely related to Paenibacillus harenae and Paenibacillus castaneae with 96.0 and 95.9 % 16S rRNA gene sequence similarities, respectively. The strain was observed to grow optimally at 28 °C and pH 7.5. The major isoprenoid quinone was found to be menaquinone-7. The dominant cellular fatty acids were identified as anteiso-C_15:0 and iso-C_15:0. The diagnostic diamino acid in the cell-wall peptidoglycan was found to be meso-diaminopimelic acid. The DNA G+C content was determined to be 41.6 mol%. On the basis of phenotypic characteristics and molecular properties, strain 1-25^T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus quercus sp. nov. is proposed. The type strain is 1-25^T (=CCTCC AB2013265^T = KCTC 33194^T).     

Paenibacillus beijingensis sp. nov., a nitrogen-fixing species isolated from wheat rhizosphere soil

A novel nitrogen-fixing bacterium, BJ-18^T, was isolated from wheat rhizosphere soil. Strain BJ-18^T was observed to be Gram-positive, facultatively anaerobic, motile and rod-shaped (0.4–0.9 μm × 2.0–2.9 μm). Phylogenetic analysis based on a partial nifH gene sequence and an assay for nitrogenase activity showed its nitrogen-fixing capacity. Phylogenetic analysis based on full 16S rRNA gene sequences suggested that strain BJ-18^T is a member of the genus Paenibacillus. High similarity of 16S rRNA gene sequence was found between BJ-18^T and Paenibacillus peoriae DSM 8320^T (99.05 %), Paenibacillus jamilae DSM 13815^T (98.86 %), Paenibacillus brasiliensis DSM 13188^T (98.55 %), Paenibacillus polymyxa DSM 36^T (98.74 %), Paenibacillus terrae DSM 15891^T (97.99 %) and Paenibacillus kribbensis JCM 11465^T (97.92 %), whereas the similarity was below 96.0 % between BJ-18^T and the other Paenibacillus species. DNA–DNA relatedness between strain BJ-18^T and P. peoriae DSM 8320^T, P. jamilae DSM 13815^T, P. brasiliensis DSM 13188^T, P. polymyxa DSM 36^T, P. kribbensis JCM 11465^T and P. terrae DSM 15891^T was determined to be 43.6 ± 2.7, 34.2 ± 5.3, 47.9 ± 6.6, 36.8 ± 3.5, 27.4 ± 4.3 and 23.6 ± 4.1 % respectively. The DNA G+C content of BJ-18^T was determined to be 45.8 mol %. The major fatty acid was identified as anteiso-C_15:0 (67.1 %). The polar lipids present in strain BJ-18^T were identified as diphosphatidylglycerol, phosphatidyl methylethanolamine, phosphatidylethanolamine and phosphatidylglycerol. The phenotypic and genotypic characteristics, and DNA–DNA relatedness data, suggest that BJ-18^T represents a novel species of the genus Paenibacillus, for which the name Paenibacillus beijingensis sp. nov. (Type strain BJ-18^T=DSM25425^T=CGMCC 1.12045^T) is proposed.     

Paenibacillus brassicae sp. nov., isolated from cabbage rhizosphere in Beijing, China

A novel Gram-positive, rod-shaped, motile, spore-forming, nitrogen-fixing bacterium, designated strain 112^T, was isolated from cabbage rhizosphere in Beijing, China. The strain was found to grow at 10–40 °C and pH 4–11, with an optimum of 30 °C and pH 7.0, respectively. Phylogenetic analysis based on a fragment of the full-length 16S rRNA gene sequence revealed that strain 112^T is a member of the genus Paenibacillus. High levels of 16S rRNA gene similarities were found between strain 112^T, Paenibacillus sabinae DSM 17841^T (97.82 %) and Paenibacillus forsythiae DSM 17842^T (97.22 %). However, the DNA–DNA hybridization values between strain 112^T and the type strains of these two species were 10.36 and 6.28 %, respectively. The predominant menaquinone was found to be menaquinone 7 (MK-7). The major fatty acids were determined to be anteiso-C_15:0 and C_16:0. The major polar lipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and unknown aminophospholipids. The cell wall peptidoglycan was found to contain meso-diaminopimelic acid. The DNA G+C content was determined to be 55.4 mol%. On the basis of its phenotypic characteristics, 16S rRNA gene sequence analysis and the value of DNA–DNA hybridization, strain 112^T is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus brassicae sp. nov. is proposed. The type strain is 112^T (= ACCC 01125^T = DSM 24983^T).     

Nonomuraea maheshkhaliensis sp. nov., a novel actinomycete isolated from mangrove rhizosphere mud

A strain of Nonomuraea was isolated from Maheshkhali, Cox's Bazar, an unexplored region of Bangladesh. Strain 16-5-14(T) is a Gram-positive, aerobic, non-motile actinomycete that formed branched substrate and aerial mycelia. On the basis of 16S rRNA gene sequence similarity studies, strain 16-5-14(T) was shown to belong to the genus Nonomuraea, being most closely related to Nonomuraea kuesteri. Chemotaxonomic data supported allocation of the strain as a member of the genus Nonomuraea. The strain 16-5-14(T) contained MK-9(H(4)) as the major menaquinone, the polar lipid was phosphatidylethanolamine and major cellular fatty acids were observed as C(16 : 0 )(15.5%), iso-C(16 : 0) (13.8%) and 10-methyl C(17 : 0) (9.6%). Results of DNA-DNA hybridization and physiological tests allowed genotypic and phenotypic differentiation of strain 16-5-14(T) from closely related species N. kuesteri. Thus 16-5-14(T) represents a novel species of the genus Nonomuraea. On the basis of evaluation of the morphological, physiological and chemotaxonomic characteristics, 16S rRNA gene sequence comparisons and DNA-DNA hybridization, Nonomuraea maheshkhaliensis sp. nov. (type strain, 16-5-14(T)=JCM 13929(T)=MTCC 8545(T)) is proposed.     

Chryseobacterium zeae sp. nov., Chryseobacterium arachidis sp. nov., and Chryseobacterium geocarposphaerae sp. nov. isolated from the rhizosphere environment

Four yellow pigmented strains (91A-561^T, 91A-576, 91A-593^T, and JM-1085^T) isolated from plant materials, showed 97.2–98.7 % 16S rRNA gene sequence similarities among each other and were studied in a polyphasic approach for their taxonomic allocation. Cells of all four isolates were rod-shaped and stained Gram-negative. Comparative 16S rRNA gene sequence analysis showed that the four bacteria had highest sequence similarities to Chryseobacterium formosense (97.2–98.7 %), Chryseobacterium gwangjuense (97.1–97.8 %), and Chryseobacterium defluvii (94.6–98.0 %). Sequence similarities to all other Chryseobacterium species were below 97.5 %. Fatty acid analysis of the four strains showed Chryseobacterium typical profiles consisting of major fatty acids C_15:0 iso, C_15:0 iso 2-OH/C_16:1 ω7c, C_17:1 iso ω9c, and C_17:0 iso 3-OH, but showed also slight differences. DNA–DNA hybridizations with type strains of C. gwangjuense, C. formosense, and C. defluvii resulted in values below 70 %. Isolates 91A-561^T and 91A-576 showed DNA–DNA hybridization values >80 % indicating that they belonged to the same species; but nucleic acid fingerprinting showed that the two isolates represent two different strains. DNA–DNA hybridization results and the differentiating biochemical and chemotaxonomic properties showed, that both strains 91A-561^T and 91A-576 represent a novel species, for which the name Chryseobacterium geocarposphaerae sp. nov. (type strain 91A-561^T=LMG 27811^T=CCM 8488^T) is proposed. Strains 91A-593^T and JM-1085^T represent two additional new species for which we propose the names Chyrseobacterium zeae sp. nov. (type strain JM-1085^T=LMG 27809^T, =CCM 8491^T) and Chryseobacterium arachidis sp. nov. (type strain 91A-593^T=LMG 27813^T, =CCM 8489^T), respectively.