Analysis of phospholipids and ornithine-containing lipids from Mesorhizobium spp

Mesorhizobium alexandrii sp. nov., isolated from phycosphere microbiota of PSTs-producing marine dinoflagellate Alexandrium minutum amtk4

An aerobic, Gram-stain-negative, motile and rod-shaped bacterial strain, designated as Z1-4^T, was isolated from the phycosphere microbiota of marine dinoflagellate Alexandrium minutum that produces paralytic shellfish poisoning toxins. Phylogenetic analysis based on 16S rRNA gene sequences showed that the new isolate belongs to the genus Mesorhizobium, and it was closely related to Mesorhizobium waimense LMG 28228^T and Mesorhizobium amorphae LMG 18977^T with both 16S rRNA gene sequence similarities of 97.3%. The values of average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) relatedness between strain Z1-4^T and its relatives are both well below the thresholds used for the delineation of a new species. A genome-based phylogenetic tree constructed by up-to-date bacterial core gene set (UBCG) indicates that strain Z1-4^T forms an independent branch within the genus Mesorhizobium. The respiratory quinone of strain Z1-4^T was Q-10. The major fatty acids were similar to other members of the genus Mesorhizobium containing the summed feature 8, C_16:0, C_19:0cycloω8c, C_17:0 and summed feature 3. The polar lipids are phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid, five glycolipids and seven unknown polar lipids. The DNA G + C content was determined to be 62.1 mol % based on its genomic sequence. Combined evidences based on the genotypic, chemotaxonomic and phenotypic characteristics clearly indicates that strain Z1-4^T represents a novel species of the genus Mesorhizobium, for which the name Mesorhizobium alexandrii sp. nov. is proposed. The type strain is Z1-4^T (= KCTC 72512^T = CCTCC AB 2019101^T).

Mesorhizobium bacterial strains isolated from the legume Lotus corniculatus are an alternative source for the production of polyhydroxyalkanoates (PHAs) to obtain bioplastics

Polyhydroxyalkanoic acids (PHAs) are natural polyesters that can be used to produce bioplastics which are biodegradable. Numerous microorganisms accumulate PHAs as energy reserves. Combinations of different PHAs monomers lead to the production of bioplastics with very different properties. In the present work, we show the capability of strains belonging to various phylogenetic lineages within the genus Mesorhizobium, isolated from Lotus corniculatus nodules, to produce different PHA monomers. Among our strains, we found the production of 3-hydroxybutyrate, 3-hydroxyvalerate, 3-hydroxydodecanoate, and 3-hydroxyhexadecanoate. Most of the PHA-positive strains were phylogenetically related to the species M. jarvisii. However, our findings suggest that the ability to produce different monomers forming PHAs is strain-dependent.

Pseudaminobacter manganicus sp. nov., isolated from sludge of a manganese mine

A Gram-staining-negative, aerobic, non-motile, capsule-forming and rod-shaped bacterium, designated JH-7T, was isolated from sludge of a manganese mine. The 16S rRNA gene sequence of JH-7T showed highest similarities to those of Pseudaminobacter salicylatoxidans BN12T (97.4 %), Mesorhizobiumthiogangeticum SJTT (97.0 %) and Pseudaminobacter defluvii THI 051T (96.5 %). Phylogenetic trees clustered JH-7T together with P. salicylatoxidans BN12Tand P. defluvii THI 051T. The DNA-DNA hybridization values between JH-7T and P. salicylatoxidans DSM 6986T and between JH-7T and M. thiogangeticum DSM 17097T were 34.8 and 20.1 %, respectively. The major fatty acids of JH-7T (>10 %) were C18 : 1ω7c, C19 : 0cyclo ω8c and C16 : 0. The genomic DNA G+C content was 61.6 mol%. The polyamines of JH-7T were sym-homospermidine (83 %) and putrescine (17 %), and the respiratory quinone was ubiquinone-10. The major polar lipids were phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, two unidentified aminolipids and two unidentified lipids. Compared with the members of the genera Pseudaminobacter and Mesorhizobium, JH-7T showed some unique physiological and biochemical characters, such as being negative for H2S production, hydrolysis of Tween 40 and Tween 60, esterase lipase (C8) activity and assimilation of d-ribose and positive for acid production from d-galactose and assimilation of d-fructose. On the basis of the results of the polyphasic taxonomic analysis, JH-7T was considered to represent a novel species of the genus Pseudaminobacter, for which the name Pseudaminobacter manganicus sp. nov. is proposed. The type strain is JH-7T (=KCTC 52258T=CCTCC AB 2016107T).

Structure, biosynthesis and function of unusual lipids A from nodule-inducing and N2-fixing bacteria

This review focuses on the chemistry and structures of (Brady)rhizobium lipids A, indispensable parts of lipopolysaccharides. These lipids contain unusual (ω-1) hydroxylated very long chain fatty acids, which are synthesized by a very limited group of bacteria, besides rhizobia. The significance and requirement of the very long chain fatty acids for outer membrane stability as well as the genetics of the synthesis pathway are discussed. The biological role of these fatty acids for bacterial life in extremely different environments (soil and intracellular space within nodules) is also considered.

Profiling of ornithine lipids in bacterial extracts of Rhodobacter sphaeroides by reversed-phase liquid chromatography with electrospray ionization and multistage mass spectrometry (RPLC-ESI-MS(n))

Ornithine lipids (OLs), a sub-group of the large (and of emerging interest) family of lipoamino acids of bacterial origin, contain a 3-hydroxy fatty acyl chain linked via an amide bond to the α-amino group of ornithine and via an ester bond to a second fatty acyl chain. OLs in extracts of Rhodobacter sphaeroides (R. sphaeroides) were investigated by high-performance reversed phase liquid chromatography (RPLC) with electrospray ionization mass spectrometry (ESI-MS) in negative ion mode using a linear ion trap (LIT). The presence of OLs bearing both saturated (i.e, 16:0, 17:0, 18:0, 19:0 and 20:0) and unsaturated chains (i.e., 18:1, 19:1, 19:2 and 20:1) was ascertained and their identification, even for isomeric, low abundance and partially co-eluting species, was achieved by low-energy collision induced dissociation (CID) multistage mass spectrometry (MS(n), n = 2-4). OLs signatures found in two R. sphaeroides strains, i.e., wild type 2.4.1 and mutant R26, were examined and up to 16 and 17 different OL species were successfully identified, respectively. OLs in both bacterial strains were characterized by several combinations of fatty chains on ester-linked and amide-linked 3-OH fatty acids. Multistage MS spectra of monoenoic amide-linked 3-OH acyl chains, allowed the identification of positional isomer of OL containing 18:1 (i.e. 9-octadecenoic) and 20:1 (i.e. 11-eicosenoic) fatty acids. The most abundant OL ([M-H](-) at m/z 717.5) in R. sphaeroides R26 was identified as OL 3-OH 20:1/19:1 (i.e., 3-OH-eicosenoic acid amide-linked to ornithine and esterified to a nonadecenoic chain containing a cyclopropane ring). An unusual OL (m/z 689.5 for the [M-H](-) ion), most likely containing a cyclopropene ester-linked acyl chain (i.e., OL 3-OH 18:0/19:2), was retrieved only in the carotenoidless mutant strain R26. Based on the biosynthetic pathways already known for cyclopropa(e)ne ring-including acyl chains, a plausible explanation was invoked for the enzymatic generation of this ester-linked chain in R. sphaeroides.

High molecular weight bioemulsifiers, main properties and potential environmental and biomedical applications

High molecular weight bioemulsifiers are amphipathic polysaccharides, proteins, lipopolysaccharides, lipoproteins, or complex mixtures of these biopolymers, produced by a wide variety of microorganisms. They are characterized by highly structural diversity and have the ability to decrease the surface and interfacial tension at the surface and interface respectively and/or emulsify hydrophobic compounds. Emulsan, fatty acids, phospholipids, neutral lipids, exopolysaccharides, vesicles and fimbriae are among the most popular high molecular weight bioemulsifiers. They have great physic-chemical properties like tolerance to extreme conditions of pH, temperature and salinity, low toxicity and biodegradability. Owing their emulsion forming and breaking capacities, solubilization, mobilization and dispersion activities and their viscosity reduction activity; they possess great environmental application as enhancer of hydrocarbon biodegradation and for microbial enhanced oil recovery. Besides, they are applied in biomedical fields for their antimicrobial and anti-adhesive activities and involvement in immune responses.

Hartmannibacter diazotrophicus gen. nov., sp. nov., a phosphate-solubilizing and nitrogen-fixing alphaproteobacterium isolated from the rhizosphere of a natural salt-meadow plant

A phosphate-mobilizing, Gram-negative bacterium was isolated from rhizospheric soil of Plantago winteri from a natural salt meadow as part of an investigation of rhizospheric bacteria from salt-resistant plant species and evaluation of their plant-growth-promoting abilities. Cells were rods, motile, strictly aerobic, oxidase-positive and catalase-negative. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain E19T was distinct from other taxa within the class Alphaproteobacteria . Strain E19T showed less than 93.5 % 16S rRNA gene sequence similarity with members of the genera Rhizobium (≤93.5 %), Labrenzia (≤93.1 %), Stappia (≤93.1 %), Aureimonas (≤93.1 %) and Mesorhizobium (≤93.0 %) and was most closely related to Rhizobium rhizoryzae (93.5 % 16S rRNA gene sequence similarity to the type strain). The sole respiratory quinone was Q-10, and the polar lipids comprised phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, an aminolipid and an unidentified phospholipid. Major fatty acids were C18 : 1ω7c (71.4 %), summed feature 2 (C14 : 0 3-OH and/or iso-C16 : 1; 8.3 %), C20 : 0 (7.9 %) and C16 : 0 (6.1 %). The DNA G+C content of strain E19T was 59.9±0.7 mol%. The capacity for nitrogen fixation was confirmed by the presence of the nifH gene and the acetylene reduction assay. On the basis of the results of our polyphasic taxonomic study, the new isolate represents a novel genus and species, for which the name Hartmannibacter diazotrophicus gen. nov., sp. nov. is proposed. The type strain of Hartmannibacter diazotrophicus is E19T ( = LMG 27460T = KACC 17263T).

Mesorhizobium qingshengii sp. nov., isolated from effective nodules of Astragalus sinicus

In a study on the diversity of rhizobia isolated from root nodules of Astragalus sinicus, five strains showed identical 16S rRNA gene sequences. They were related most closely to the type strains of Mesorhizobium loti , Mesorhizobium shangrilense , Mesorhizobium ciceri and Mesorhizobium australicum , with sequence similarities of 99.6–99.8 %. A polyphasic approach, including 16S–23S intergenic spacer (IGS) RFLP, comparative sequence analysis of 16S rRNA, atpD, glnII and recA genes, DNA–DNA hybridization and phenotypic tests, clustered the five isolates into a coherent group distinct from all recognized Mesorhizobium species. Except for strain CCBAU 33446, from which no symbiotic gene was detected, the four remaining strains shared identical nifH and nodC gene sequences and nodulated with Astragalus sinicus. In addition, these five strains showed similar but different fingerprints in IGS-RFLP and BOX-repeat-based PCR, indicating that they were not clones of the same strain. They were also distinguished from recognized Mesorhizobium species by several phenotypic features and fatty acid profiles. Based upon all the results, we suggest that the five strains represent a novel species for which the name Mesorhizobium qingshengii sp. nov. is proposed. The type strain is CCBAU 33460T ( = CGMCC 1.12097T = LMG 26793T = HAMBI 3277T). The DNA G+C content of the type strain is 59.52 mol% (T m).

Aquamicrobium ahrensii sp. nov. and Aquamicrobium segne sp. nov., isolated from experimental biofilters

Two groups of Gram-negative, aerobic bacterial strains previously isolated from experimental biofilters were investigated to determine their taxonomic position. Based on their 16S rRNA gene sequences, these isolates formed two distinct groups within the genus Aquamicrobium . The gene sequence similarities of the new isolates to the type strains of Aquamicrobium species were below 98.3 %. The presence of ubiquinone-10, C18 : 1 cis 11 as the predominant fatty acid and a polar lipid pattern with phosphatidylglycerol, phosphatidylcholine, diphosphatidylglycerol and phosphatidylethanolamine was in accordance with the characteristics of this genus. The results of DNA–DNA hybridization, biochemical tests and chemotaxonomic properties allowed genotypic and phenotypic differentiation of the strains from all recognized species of the genus Aquamicrobium . Therefore, the isolates were assigned to two novel species of this genus for which the names Aquamicrobium ahrensii sp. nov. (type strain 905/1T = DSM 19730T = CCUG 55251T) and Aquamicrobium segne sp. nov. (type strain 1006/1T = DSM 19714T = CCUG 55250T) are proposed. An emended description of the genus Aquamicrobium is also presented.

Accumulation of glycolipids and other non-phosphorous lipids in Agrobacterium tumefaciens grown under phosphate deprivation

Phosphate deficiency is characteristic for many natural habitats, resulting in different physiological responses in plants and bacteria including the replacement of phospholipids by glycolipids and other phosphorous-free lipids. The plant pathogenic bacterium Agrobacterium tumefaciens, which is free of glycolipids under full nutrition, harbors an open reading frame (ORF) coding for a processive glycosyltransferase (named as Pgt). This glycosyltransferase was previously shown to synthesize glucosylgalactosyldiacylglycerol (GGD) and digalactosyldiacylglycerol (DGD) after heterologous expression. The native function of this enzyme and the conditions for its activation remained unknown. We show here that Pgt is active under phosphate deprivation synthesizing GGD and DGD in Agrobacterium. A corresponding deletion mutant (Δpgt) is free of these two glycolipids. Glycolipid accumulation is mainly regulated by substrate (diacylglycerol) availability. Diacylglycerol and the total fatty acid pool are characterized by an altered acyl composition in dependence of the phosphate status with a strong decrease of 18:1 and concomitant increase of 19:0 cyclo during phosphate deprivation. Furthermore, Agrobacterium accumulates two additional unknown glycolipids and diacylglycerol trimethylhomoserine (DGTS) during phosphate deprivation. Accumulation of all these lipids is accompanied by a reduction in phospholipids from 75 to 45% in the wild type. A further non-phosphorous lipid, ornithine lipid, was not increased but its degree of hydroxylation was elevated under phosphate deprivation. The lack of GGD and DGD in the Δpgt mutant has no effect on growth and virulence of Agrobacterium, suggesting that these two lipids are functionally replaced by DGTS and the two unknown glycolipids under phosphate deprivation.

Mesorhizobium muleiense sp. nov., nodulating with Cicer arietinum L

Three chickpea rhizobial strains (CCBAU 83963(T), CCBAU 83939 and CCBAU 83908), which were identified previously as representing a distinctive genospecies, were further studied here and compared taxonomically with related species in the genus Mesorhizobium. Results from SDS-PAGE of whole-cell soluble proteins revealed differences from closely related recognized species of the genus Mesorhizobium. Levels of DNA-DNA relatedness were 15.28-50.97% between strain CCBAU 83963(T) and the type strains of recognized Mesorhizobium species (except for Mesorhizobium thiogangeticum). Strain CCBAU 83963(T) contained fatty acids characteristic of members of the genus Mesorhizobium, but it possessed high concentrations of C(19:0) cyclo ω8c and iso-C(17:0). Strain CCBAU 83963(T) had phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol as major polar lipids, and an ornithine-containing lipid, phosphatidyl-N-dimethylethanolamine and cardiolipin as minor components. Nodulation tests demonstrated the distinct symbiotic character of strain CCBAU 83963(T); only Cicer arietinum, its host plant, could be invaded to form effective nitrogen-fixing nodules. The narrow spectrum of utilization of sole carbon sources, lower resistance to antibiotics, and NaCl, pH and temperature growth ranges differentiated these novel rhizobia from recognized species of the genus Mesorhizobium. Based on the data presented, the three novel rhizobial strains are considered to represent a novel species of the genus Mesorhizobium, for which the name Mesorhizobium muleiense sp. nov. is proposed. The type strain is CCBAU 83963(T) (=HAMBI 3264(T)=CGMCC 1.11022(T)).

A processive glycosyltransferase involved in glycolipid synthesis during phosphate deprivation in Mesorhizobium loti

Natural habitats are often characterized by a low availability of phosphate. In plants and many bacteria, phosphate deficiency causes different physiological responses, including the replacement of phosphoglycerolipids in the membranes with nonphosphorous lipids. We describe here a processive glycosyltransferase (Pgt) in Mesorhizobium loti (Rhizobiales) involved in the synthesis of di- and triglycosyldiacylglycerols (DGlycD and TGlycD) during phosphate deprivation. Cells of the corresponding Δpgt deletion mutant are deficient in DGlycD and TGlycD. Additional Pgt-independent lipids accumulate in Mesorhizobium after phosphate starvation, including diacylglyceryl trimethylhomoserine (DGTS) and ornithine lipid (OL). The accumulation of the nonphosphorous lipids during phosphate deprivation leads to the reduction of phosphoglycerolipids from 90 to 50%. Nodulation experiments of Mesorhizobium wild type and the Δpgt mutant with its host plant, Lotus japonicus, revealed that DGlycD and TGlycD are not essential for nodulation under phosphate-replete or -deficient conditions. Lipid measurements showed that the Pgt-independent lipids including OL and DGTS accumulate to higher proportions in the Δpgt mutant and therefore might functionally replace DGlycD and TGlycD during phosphate deprivation.

Chelativorans multitrophicus gen. nov., sp. nov. and Chelativorans oligotrophicus sp. nov., aerobic EDTA-degrading bacteria

Two previously isolated strains (DSM 9103(T) and LPM-4(T)) able to grow with EDTA (facultatively and obligately, respectively) as the source of carbon, nitrogen and energy were investigated in order to clarify their taxonomic positions. The strains were strictly aerobic, Gram-negative, asporogenous and non-motile rods that required biotin for growth. Reproduction occurred by binary fission. The strains were mesophilic and neutrophilic. Their major fatty acids were summed feature 7 (consisting of C(18 : 1)omega7c, C(18 : 1)omega9t and/or C(18 : 1)omega12t) and C(19 : 0) cyclo omega8c. The polyamine pattern revealed homospermidine as a major polyamine. Predominant polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, phosphatidyldimethylethanolamine, phosphatidylmonomethylethanolamine and diphosphatidylglycerol. Mesorhizobium-specific ornithine lipid was absent. The predominant isoprenoid quinone was Q-10. The DNA G+C values were 60.8 and 63.1 mol% (T(m)) for strains LPM-4(T) and DSM 9103(T), respectively. The level of 16S rRNA gene sequence similarity between these EDTA-utilizers was 99.3 % while the DNA-DNA hybridization value was only 37 %. Both strains were phylogenetically related to members of the genera Aminobacter and Mesorhizobium (95-97 % sequence similarity). However, DNA-DNA hybridization values between the novel EDTA-degrading strains and Aminobacter aminovorans DSM 7048(T) and Mesorhizobium loti DSM 2626(T) were low (10-11 %). Based on their genomic and phenotypic properties, the new alphaproteobacterial strains are assigned to a novel genus, Chelativorans gen. nov., with the names Chelativorans multitrophicus sp. nov. (type strain DSM 9103(T)=VKM B-2394(T)) and Chelativorans oligotrophicus sp. nov. (type strain LPM-4(T)=VKM B-2395(T)=DSM 19276(T)).

A shotgun lipidomics approach in Sinorhizobium meliloti as a tool in functional genomics

A shotgun lipidomics approach that allowed the analysis of eight lipid classes directly from crude extracts of the soil bacterium Sinorhizobium meliloti is presented. New MS-MS transitions are reported for the analysis of monomethylphosphatidylethanolamines, dimethylphosphatidylethanolamines, and three bacterial non-phosphorus-containing lipid classes [sulfoquinovosyldiacylglycerols, ornithines, and diacylglyceryl-(N,N,N-trimethyl)-homoserines]. Unique MS-MS transitions allowed the analysis of isomeric species from various lipid classes without chromatography. Analyses required small sample amounts and minimal preparation; thus, this methodology has excellent potential to be used as a screening tool for the analysis of large numbers of samples in functional genomics studies. FA distributions within lipid classes of S. meliloti are described for the first time, and the relative positions of fatty acyl substituents (sn-1, sn-2) in phospholipids are presented. FA distributions in diacylglyceryl-(N,N,N-trimethyl)-homoserines were identical to those of phospholipids, indicating a common biosynthetic origin for these lipids. The method was applied to the analysis of mutants deficient in the PhoB regulator protein. Increased lipid cyclopropanation was observed in PhoB-deficient mutants under P(i) starvation.

Description of Pseudochrobactrum gen. nov., with the two species Pseudochrobactrum asaccharolyticum sp. nov. and Pseudochrobactrum saccharolyticum sp. nov

Two Gram-negative, rod-shaped, oxidase-positive, non-spore-forming, non-motile bacteria (CCUG 46016T and CCUG 33852T), isolated from a knee aspirate of a 66-year-old man and an industrial glue, respectively, were studied for their taxonomic position. On the basis of chemotaxonomic data [i.e. major ubiquinone (Q-10), major polar lipids (phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine) and major fatty acids (C18 : 1 ω7c and C19 : 0 cyclo ω8c)] and 16S rRNA gene sequence similarity, both strains belong to the Alphaproteobacteria. The presence of spermidine and putrescine as the predominant polyamines in CCUG 46016T were in agreement with its phylogenetic affiliation in the vicinity of the genus Ochrobactrum. 16S rRNA gene sequence similarities between both strains and established species within the genera Bartonella, Ochrobactrum and Brucella were less than 95 %. Although both organisms showed highest 16S rRNA gene sequence similarity to members of Brucella, phenotypic features (including chemotaxonomic features) were more like those of members of the genus Ochrobactrum. Sequence comparison of the recA genes confirmed the separate phylogenetic position of the two strains. On the basis of DNA–DNA pairing results and physiological and biochemical data, the two strains can be clearly differentiated from each other and from all known Ochrobactrum species. It is evident that these organisms represent two novel species in a new genus, Pseudochrobactrum gen. nov., for which the names Pseudochrobactrum asaccharolyticum sp. nov. (the type species, type strain CCUG 46016T=CIP 108977T) and Pseudochrobactrum saccharolyticum sp. nov. (type strain CCUG 33852T=CIP 108976T) are proposed.

Aurantimonas coralicida gen. nov., sp. nov., the causative agent of white plague type II on Caribbean scleractinian corals

A bacterium previously isolated from a diseased colony of the scleractinian coral Dichocoenia stokesi (common name elliptical star coral) was subjected to a detailed polyphasic taxonomic characterization. The isolate, designated WP1T, was halophilic and strictly aerobic and formed golden-orange-pigmented colonies after prolonged incubation. Cells of WP1T were gram-negative, rod-shaped and showed a characteristic branching rod morphology. Chemotaxonomically, WP1T was characterized by having Q-10 as the major respiratory lipoquinone and sym-homospermidine as the main component of the cellular polyamine content. The predominant constituent in the cellular fatty acid profile was C18:1 omega7c, along with C19:0 cyclo omega8c and C16:0. Other fatty acids present in smaller amounts were C17:0, C18:0, C16:1 omega7c, C20:1 omega7c and C18:1 2-OH. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine. Minor amounts of diphosphatidylglycerol, phosphatidylmonomethylethanolamine and phosphatidyldimethylethanolamine were present. The G + C content of the genomic DNA was 66.3 mol%. Phylogenetic analysis of the 16S rRNA gene sequence showed that WP1T represents a separate subline of descent within the order 'Rhizobiales' of the 'Alphaproteobacteria'. The new line of descent falls within the group of families that includes the Rhizobiaceae, Bartonellaceae, Brucellaceae and 'Phyllobacteriaceae', with no particular relative within this group. The 16S rRNA gene sequence similarity to all established taxa within this group was not higher than 92.0% (to Mesorhizobium mediterraneum). To accommodate this emerging coral pathogen, the creation of a new genus and species is proposed, Aurantimonas coralicida gen. nov., sp. nov. (type strain WP1T = CIP 107386T = DSM 14790T).

Towards a standardized format for the description of a novel species (of an established genus): Ochrobactrum gallinifaecis sp. nov

A format for the description of single novel species is proposed, which should facilitate the reviewing process by assisting the provision of data in a standardized form. The abstract must be short and concise, highlighting phylogenetic position, morphology and chemotaxonomy for genus affiliation, the genotypic and phenotypic basis for species differentiation, and the name and deposition numbers from two public culture collections in different countries for the type strain: A Gram-negative, rod-shaped, non-spore-forming bacterium (Iso 196(T)) was isolated from chicken faeces. On the basis of 16S rRNA gene sequence similarity, strain Iso 196(T) was shown to belong to the alpha-2 subclass of the Proteobacteria related to Ochrobactrum tritici (95.6%), Ochrobactrum grignonense (95.0%) and Ochrobactrum anthropi (94.6%), and the phylogenetic distance from any validly described species within the genus Brucella was less than 95%. Chemotaxonomic data (major ubiquinone - Q-10; major polyamines - spermidine and putrescine; major polar lipids - phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine; major fatty acids - C(18 : 1)omega7c and C(19 : 0) cyclo omega8c) supported the affiliation of strain Iso 196(T) to the genus Ochrobactrum. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain Iso 196(T) from the four validly published Ochrobactrum species. Iso 196(T) therefore represents a new species, for which the name Ochrobactrum gallinifaecis sp. nov. is proposed, with the type strain Iso 196(T) (= DSM 15295(T) = CIP 107753(T)).