Brucella pituitosa strain BU72, a new hydrocarbonoclastic bacterium through exopolysaccharide-based surfactant production

Hydrocarbon and heavy metal pollution are amongst the most severe and prevalent environmental problems due to their toxicity and persistence. Bioremediation using microorganisms is considered one of the most effective ways to treat polluted sites. In the present study, we unveil the bioremediation potential of Brucella pituitosa strain BU72. Besides its ability to grow on multiple hydrocarbons as the sole carbon source and highly tolerant to several heavy metals, BU72 produces different exopolysaccharide-based surfactants (EBS) when grown with glucose or with crude oil as sole carbon source. These EBS demonstrated particular and specific functional groups as determined by Fourier transform infrared (FTIR) spectral analysis that showed a strong absorption peak at 3250 cm-1 generated by the -OH group for both EBS. The FTIR spectra of the produced EBS revealed major differences in functional groups and protein content. To better understand the EBS production coupled with the degradation of hydrocarbons and heavy metal resistance, the genome of strain BU72 was sequenced. Annotation of the genome revealed multiple genes putatively involved in EBS production pathways coupled with resistance to heavy metals genes such as arsenic tolerance and cobalt-zinc-cadmium resistance. The genome sequence analysis showed the potential of BU72 to synthesise secondary metabolites and the presence of genes involved in plant growth promotion. Here, we describe the physiological, metabolic, and genomic characteristics of Brucella pituitosa strain BU72, indicating its potential as a bioremediation agent.

Ochrobactrum chromiisoli sp. nov., Isolated from Chromium-Contaminated Soil

A Gram-stain-negative, non-spore-forming, flagellated, motile, aerobic, rod-shaped bacteria strain, designated YY2XT, was isolated from chromium-contaminated soil. Phylogenetic analysis based on 16S rRNA gene, recA gene, and whole genome indicated that the strain represented a new member of the genus Ochrobactrum, family Brucellaceae, class Alphaproteobacteria. The phylogenetic trees based on 16 s rRNA gene, revealed that Falsochrobactrum ovis DSM26720T (96.7%), Ochrobactrum gallinifaecis DSM15295T (96.2%), and Pseudochrobactrum asaccharolyticum DSM25619T (96.2%) are the most closely related phylogenetic neighbors of strain YY2XT. The draft genome of YY2XT was approximately 4,650,646 bp in size with a G + C content of 53.0 mol%. Average nucleotide identity and digital DNA-DNA hybridization values among strain YY2XT and the selected Brucellaceae species were 71.4-83.1% and 13.5-42.7%, which are below the recommended cut-off values for species delineation. Growth of strain YY2XT occurred within pH 5-10 (optimum, pH 7-8), 4 ℃-42 °C (optimum, 30 °C), and NaCl concentrations of 0.0-6.0% (optimum, 1.0%). Major quinone system was ubiquinone 10, the major fatty acids were C16:0, C18:1ω7c, and C16:1ω7c and the major polyamines were spermidine and putrescine. Major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, and four undefined lipids. On the basis of the phenotypic, genotypic and chemotaxonomic traits, strain YY2XT was considered to represent a novel species of the genus Ochrobactrum, for which the name Ochrobactrum chromiisoli sp. nov. is proposed. The type strain is YY2XT (= CCTCC AB 2023035T = JCM 36000T).

Malathion biodegradation by a psychrotolerant bacteria Ochrobactrum sp. M1D and metabolic pathway analysis

An organophosphorus pesticide malathion biodegradation was investigated by using the bacteria Ochrobactrum sp. M1D isolated from a soil sample of peach orchards in Palampur, District Kangra, Himachal Pradesh (India). The bacterium was able to utilize malathion as the sole source of carbon and energy. The isolated bacterium was found psychrotolerant and could degrade 100% of 100 mg l^-1 malathion in minimal salt medium at 20°C, pH 7·0 within 12 days with no major significant metabolites left at the end of the study. Through GCMS analysis, methyl phosphate, diethyl maleate, and diethyl 2-mercaptosuccinate were detected and identified as the major pathway metabolites. Based on the GCMS profile, three probable degradation pathways were interpreted. The present study is the first report of malathion biodegradation at both the psychrophilic and mesophilic conditions by any psychrotolerant strain and also through multiple degradation pathways. In the future, the strain can be explored to bio-remediate the malathion contaminated soil in the cold climatic region and to utilize the enzymatic systems for advanced biotechnology applications.

Genetic and metabolic diversities of rhizobacteria isolated from degraded soil of Ethiopia

Genetic and metabolic diversities of rhizobacteria are the fundamental sources for their adaptation to cope with abiotic and biotic stresses in order to enhance growth and health of plants in the soil. Thus, this study was initiated to assess the genetic and metabolic diversities of rhizobacteria isolated from plants grown in degraded soil through BOX-PCR and partial sequencing of 16S rRNA genes. A total of eighty isolates were recovered and subjected to phenotypic profiling of carbohydrate and amino acid utilization, BOX PCR and 16S rRNA profiling. The phenotypic profiling showed remarkable metabolic versatility with Ochrobactrum spp, Pseudomonas spp and Klebsiella spp, and BOX-PCR showed greater discriminatory power for fingerprinting of rhizobacterial isolates with high degree of polymorphism. Bacillus spp showed the highest Simpson's diversity Index. The 16S rRNA genes sequence assigned the rhizobacteria to phyla Proteobacteria with Gammaproteobacteria and Alphaproteobacteria classes and Firmicutes with Bacilli class. The data also showed that the most dominant species were Pseudomonas and Ochrobactrum. Genetic and metabolic diversities of the rhizobacterial isolates reveal the potential of these microbes for plant growth improvement under water deficient soil after testing other inoculant traits.

The Genus Ochrobactrum as Major Opportunistic Pathogens

Ochrobactrum species are non-enteric, Gram-negative organisms that are closely related to the genus Brucella. Since the designation of the genus in 1988, several distinct species have now been characterised and implicated as opportunistic pathogens in multiple outbreaks. Here, we examine the genus, its members, diagnostic tools used for identification, data from recent Ochrobactrum whole genome sequencing and the pathogenicity associated with reported Ochrobactrum infections. This review identified 128 instances of Ochrobactrum spp. infections that have been discussed in the literature. These findings indicate that infection review programs should consider investigation of possible Ochrobactrum spp. outbreaks if these bacteria are clinically isolated in more than one patient and that Ochrobactrum spp. are more important pathogens than previously thought.

Application of Whole Genome Sequencing and Pan-Family Multi-Locus Sequence Analysis to Characterize Relationships Within the Family Brucellaceae

The bacterial family Brucellaceae is currently composed of seven genera, including species of the genus Brucella, a number of which are significant veterinary and zoonotic pathogens. The bacteriological identification of pathogenic Brucella spp. may be hindered by their close phenotypic similarity to other members of the Brucellaceae, particularly of the genus Ochrobactrum. Additionally, a number of novel atypical Brucella taxa have recently been identified, which exhibit greater genetic diversity than observed within the previously described species, and which share genomic features with organisms outside of the genus. Furthermore, previous work has indicated that the genus Ochrobactrum is polyphyletic, raising further questions regarding the relationship between the genus Brucella and wider Brucellaceae. We have applied whole genome sequencing (WGS) and pan-family multi-locus sequence analysis (MLSA) approaches to a comprehensive panel of Brucellaceae type strains, in order to characterize relationships within the family. Phylogenies based on WGS core genome alignments were able to resolve phylogenetic relationships of 31 non-Brucella spp. type strains from within the family, alongside type strains of twelve Brucella species. A phylogeny based on concatenated pan-family MLSA data was largely consistent with WGS based analyses. Notably, recently described atypical Brucella isolates were consistently placed in a single clade with existing species, clearly distinct from all members of the genus Ochrobactrum and wider family. Both WGS and MLSA methods closely grouped Brucella spp. with a sub-set of Ochrobactrum species. However, results also confirmed that the genus Ochrobactrum is polyphyletic, with seven species forming a separate grouping. The pan-family MLSA scheme was subsequently applied to a panel of 50 field strains of the family Brucellaceae, isolated from a wide variety of sources. This analysis confirmed the utility of the pan-Brucellaceae MLSA scheme in placing field isolates in relation to recognized type strains. However, a significant number of these isolates did not cluster with currently identified type strains, suggesting the existence of additional taxonomic diversity within some members of the Brucellaceae. The WGS and pan-family MLSA approaches applied here provide valuable tools for resolving the identity and phylogenetic relationships of isolates from an expanding bacterial family containing a number of important pathogens.

Analysis of 1,000+ Type-Strain Genomes Substantially Improves Taxonomic Classification of Alphaproteobacteria

The class Alphaproteobacteria is comprised of a diverse assemblage of Gram-negative bacteria that includes organisms of varying morphologies, physiologies and habitat preferences many of which are of clinical and ecological importance. Alphaproteobacteria classification has proved to be difficult, not least when taxonomic decisions rested heavily on a limited number of phenotypic features and interpretation of poorly resolved 16S rRNA gene trees. Despite progress in recent years regarding the classification of bacteria assigned to the class, there remains a need to further clarify taxonomic relationships. Here, draft genome sequences of a collection of genomes of more than 1000 Alphaproteobacteria and outgroup type strains were used to infer phylogenetic trees from genome-scale data using the principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families and genera, including taxa recognized as problematic long ago but also quite recent taxa, as well as a few species were shown to be in need of revision. According proposals are made for the recognition of new orders, families and genera, as well as the transfer of a variety of species to other genera and of a variety of genera to other families. In addition, emended descriptions are given for many species mainly involving information on DNA G+C content and (approximate) genome size, both of which are confirmed as valuable taxonomic markers. Similarly, analysis of the gene content was shown to provide valuable taxonomic insights in the class. Significant incongruities between 16S rRNA gene and whole genome trees were not found in the class. The incongruities that became obvious when comparing the results of the present study with existing classifications appeared to be caused mainly by insufficiently resolved 16S rRNA gene trees or incomplete taxon sampling. Another probable cause of misclassifications in the past is the partially low overall fit of phenotypic characters to the sequence-based tree. Even though a significant degree of phylogenetic conservation was detected in all characters investigated, the overall fit to the tree varied considerably.

Ochrobactrum teleogrylli sp. nov., a pesticide-degrading bacterium isolated from the insect Teleogryllus occipitalis living in deserted cropland

A Gram-stain-negative, non-spore-forming, motile, aerobic, rod-shaped bacteria strain, designated LCB8^T, was isolated from the insect Teleogryllus occipitalis captured from a deserted cropland in Shuangliu district, Chengdu, PR China. Phylogenetic analysis on the basis of 16S rRNA gene sequence indicated that the strain represented a member of the genus Ochrobactrum, family Brucellaceae, class Alphaproteobacteria. Ochrobactrum pecoris CCUG 60088^T (97.9 %) and Ochrobactrum haematophilum CCUG 38531^T (98.8 %) were identified as the most closely related phylogenetic neighbours of strain LCB8^T. The novel strain was able to grow at salt concentrations of 0-4.5 % (w/v), pH 5-9 and temperatures of 20-42 °C. The major quinone system was ubiquinone Q-10, the major fatty acids were C_18 : 1ω7c, C_16 : 0 and C_18 : 0. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylmonomethylethanolamine, diphosphatidylglycerol and four undefined aminolipids. The major polyamines were putrescine and spermidine. Genome sequencing revealed a genome size of 4.76 Mbp and a DNA G+C content of 57.1 mol%. These phenotypic, genotypic and chemotaxonomic traits excellently supported the affiliation of LCB8^T to the genus Ochrobactrum. Pairwise determined whole-genome average nucleotide identity (ANI) values indicated that strain LCB8^T represents a novel species, for which we propose the name Ochrobactrum teleogrylli sp. nov. with the type strain LCB8^T (=KCTC 72031^T=CGMCC 1.13984^T).

Taxonomic Organization of the Family Brucellaceae Based on a Phylogenomic Approach

Deciphering the evolutionary history of pathogenic bacteria and their near neighbors may help to understand the genetic or ecological bases which led to their pathogenic behavior. The Brucellaceae family comprises zoonotic pathogenic species belonging to the genus Brucella as well as the environmental genus Ochrobactrum for which some species are considered as opportunistic pathogens. Here, we used a phylogenomic approach including a set of 145 Brucellaceae genomes representative of the family diversity and more than 40 genomes of the order Rhizobiales to infer the taxonomic relationships between the family’s species. Our results clarified some unresolved phylogenetic ambiguities, conducting to the exclusion of Mycoplana spp. out of the family Brucellaceae and the positioning of all Brucella spp. as a single genomic species within the current Ochrobactrum species diversity. Additional analyses also revealed that Ochrobactrum spp. separate into two clades, one comprising mostly environmental species while the other one includes the species considered as pathogens (Brucella spp.) or opportunistic pathogens (mainly O. anthropi, O. intermedium, and O. pseudintermedium). Finally, we show that O. intermedium is undergoing a beginning of genome reduction suggestive of an ongoing ecological niche specialization, and that some lineages of O. intermedium and O. anthropi may shift toward an adaption to the human host.

Ochrobactrum soli sp. nov., Isolated from a Korean Cattle Farm

A Gram stain negative, motile, non-spore-forming, rod-shaped, strictly aerobic, beige-pigmented bacterium, designated strain BO-7^T, was isolated from soil of cattle farm, in Seosan, Republic of Korea. On the basis of 16S rRNA gene sequencing, strain BO-7^T clustered with species of the genus Ochrobactrum and appeared closely related to O. haematophilum CCUG 38531^T (98.9%), O. daejeonense KCTC 22458^T (98.1%), O. rhizosphaerae DSM 19824^T (98.1%), O. pituitosum DSM 22207^T (98.0%), and O. pecoris DSM 23868^T (98.0%). The digital DNA-DNA hybridization and average nucleotide identity between strain BO-7^T and the closely related strains were 21.9-39.1%, 78.5-89.5%, respectively, indicating that BO-7^T is a novel species of the genus Ochrobactrum. The DNA G + C content of the genomic DNA was 57.1 mol%, and ubiquinone Q-10 was the predominant respiratory quinone. The polar lipids consisted of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylmonomethyl-ethanolamine, di-phosphatidylglycerol, the major polyamines were spermidine, putrescine, and sym-homospermidine. The major cellular fatty acids (> 5%) were C_16:0, C_19:0 cycle ω7c, and C_18:1ω7c and/or C_18:1ω6c (summed feature 8). ANI calculation, digital DNA-DNA hybridization, physiological and biochemical characteristics indicated that strain BO-7^T represents a novel species of the genus Ochrobactrum, for which the name Ochrobactrum soli sp. nov. is proposed. The type strain is BO-7^T (= KACC 19676^T = LMG 30809^T).

Ochrobactrum quorumnocens sp. nov., a quorum quenching bacterium from the potato rhizosphere, and comparative genome analysis with related type strains

Ochrobactrum spp. are ubiquitous bacteria attracting growing attention as important members of microbiomes of plants and nematodes and as a source of enzymes for biotechnology. Strain Ochrobactrum sp. A44^T was isolated from the rhizosphere of a field-grown potato in Gelderland, the Netherlands. The strain can interfere with quorum sensing (QS) of Gram-negative bacteria through inactivation of N-acyl homoserine lactones (AHLs) and protect plant tissue against soft rot pathogens, the virulence of which is governed by QS. Phylogenetic analysis based on 16S rRNA gene alone and concatenation of 16S rRNA gene and MLSA genes (groEL and gyrB) revealed that the closest relatives of A44^T are O. grignonense OgA9a^T, O. thiophenivorans DSM 7216^T, O. pseudogrignonense CCUG 30717^T, O. pituitosum CCUG 50899^T, and O. rhizosphaerae PR17^T. Genomes of all six type strains were sequenced, significantly expanding the possibility of genome-based analyses in Ochrobactrum spp. Average nucleotide identity (ANIb) and genome-to-genome distance (GGDC) values for A44^T and the related strains were below the single species thresholds (95% and 70%, respectively), with the highest scores obtained for O. pituitosum CCUG 50899^T (87.31%; 35.6%), O. rhizosphaerae PR17^T (86.80%; 34.3%), and O. grignonense OgA9a^T (86.30%; 33.6%). Distinction of A44^T from the related type strains was supported by chemotaxonomic and biochemical analyses. Comparative genomics revealed that the core genome for the newly sequenced strains comprises 2731 genes, constituting 50–66% of each individual genome. Through phenotype-to-genotype study, we found that the non-motile strain O. thiophenivorans DSM 7216^T lacks a cluster of genes related to flagella formation. Moreover, we explored the genetic background of distinct urease activity among the strains. Here, we propose to establish a novel species Ochrobactrum quorumnocens, with A44^T as the type strain (= LMG 30544^T = PCM 2957^T).

Falsochrobactrum shanghaiense sp. nov., isolated from paddy soil and emended description of the genus Falsochrobactrum

A non-spore-forming, motile, Gram-stain-negative, short rod-shaped strain, designated HN4^T, was isolated from a paddy soil sample collected in Shanghai, China. A comparative analysis o-f 16S rRNA gene sequences showed that strain HN4^T fell within the genus Falsochrobactrum, forming a clear cluster with the type strain of Falsochrobactrum ovis, with which it exhibited a 16S rRNA gene sequence similarity value of 98.2 %. Strain HN4^T grew optimally at pH 7.0, 30-35 °C and in the presence of 1 % (w/v) NaCl. It was positive for oxidase activity. Chemotaxonomic analysis showed that strain HN4^T contained ubiquinone-10 as the predominant respiratory quinone and possessed summed feature 8(C18 : 1ω7c and/or C18 : 1ω6c) and C19 : 0cyclo ω8c as predominant fatty acids. The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine. The DNA G+C content was 56.9 mol%. Strain HN4^T exhibited a DNA-DNA relatedness level of 18±1 % with Falsochrobactrum ovis CCM 8460^T. Based on the data obtained in this study, strain HN4^T represents a novel species of the genus Falsochrobactrum, for which the name Falsochrobactrumshanghaiense sp. nov. is proposed. The type strain is HN4^T (=JCM 32785^T=CCTCC AB 2018063^T).

Morphological responses to nitrogen stress deficiency of a new heterotrophic isolated strain of Ebro Delta microbial mats

Microorganisms living in hypersaline microbial mats frequently form consortia under stressful and changing environmental conditions. In this paper, the heterotrophic strain DE2010 from a microalgae consortium (Scenedesmus sp. DE2009) from Ebro Delta microbial mats has been phenotypically and genotypically characterized and identified. In addition, changes in the morphology and biomass of this bacterium in response to nitrogen deficiency stress have been evaluated by correlative light and electron microscopy (CLEM) combining differential interference contrast (DIC) microscopy and transmission electron microscopy (TEM) and scanning electron microscopy (SEM). These isolated bacteria are chemoorganoheterotrophic, gram-negative, and strictly aerobic bacteria that use a variety of amino acids, organic acids, and carbohydrates as carbon and energy sources, and they grow optimally at 27 °C in a pH range of 5 to 9 and tolerate salinity from 0 to 70‰ NaCl. The DNA-sequencing analysis of the 16S rRNA and nudC and fixH genes and the metabolic characterization highlight that strain DE2010 corresponds to the species Ochrobactrum anthropi. Cells are rod shaped, 1-3 μm in length, and 0.5 μm wide, but under deprived nitrogen conditions, cells are less abundant and become more round, reducing their length and area and, consequently, their biomass. An increase in the number of pleomorphic cells is observed in cultures grown without nitrogen using different optical and electron microscopy techniques. In addition, the amplification of the fixH gene confirms that Ochrobactrum anthropi DE2010 has the capacity to fix nitrogen, overcoming N₂-limiting conditions through a nifH-independent mechanism that is still unidentified.

Ochrobactrum endophyticum sp. nov., isolated from roots of Glycyrrhiza uralensis

A novel Gram-staining negative, motile, rod-shaped and aerobic bacterial strain, designated EGI 60010(T), was isolated from healthy roots of Glycyrrhiza uralensis F. collected from Yili County, Xinjiang Province, North-West China. The 16S rRNA gene sequence of strain EGI 60010(T) showed 97.2 % sequence similarities with Ochrobactrum anthropi ATCC 49188(T) and Ochrobactrum cytisi ESC1(T), and 97.1 % with Ochrobactrum lupini LUP21(T). The phylogenetic analysis based on 16S rRNA gene sequences showed that the new isolate clustered with members of the genera Ochrobactrum, and formed a distinct clade in the neighbour-joining tree. Q-10 was identified as the respiratory quinone for strain EGI 60010(T). The major fatty acids were summed feature 8 (C18:1 ω6c and/or C18:1 ω7c), C19:0 cyclo ω8c, summed feature 4 (C17:1 iso I/anteiso B) and C16:0. The polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylglycerol and phosphatidylcholine. The DNA G+C content of strain EGI 60010(T) was determined to be 60.4 mol%. The genomic DNA relatedness values determined between strain EGI 60010(T) and the closely related strains O. anthropi JCM 21032(T), O. cytisi CCTCC AB2014258(T) and O. lupini NBRC 102587(T) were 50.3, 50.0 and 41.6 %, respectively. Based on the results of the molecular studies supported by its differentiating phenotypic characteristics, strain EGI 60010(T) was considered to represent a novel species within the genus Ochrobactrum, for which the name Ochrobactrum endophyticum sp. nov., is proposed. The type strain is EGI 60010(T) (=CGMCC 1.15082(T) = KCTC 42485(T) = DSM 29930(T)).

Niches, population structure and genome reduction in Ochrobactrum intermedium: clues to technology-driven emergence of pathogens

Ochrobactrum intermedium is considered as an emerging human environmental opportunistic pathogen with mild virulence. The distribution of isolates and sequences described in literature and databases showed frequent association with human beings and polluted environments. As population structures are related to bacterial lifestyles, we investigated by multi-locus approach the genetic structure of a population of 65 isolates representative of the known natural distribution of O. intermedium. The population was further surveyed for genome dynamics using pulsed-field gel electrophoresis and genomics. The population displayed a clonal epidemic structure with events of recombination that occurred mainly in clonal complexes. Concerning biogeography, clones were shared by human and environments and were both cosmopolitan and local. The main cosmopolitan clone was genetically and genomically stable, and grouped isolates that all harbored an atypical insertion in the rrs. Ubiquitism and stability of this major clone suggested a clonal succes in a particular niche. Events of genomic reduction were detected in the population and the deleted genomic content was described for one isolate. O. intermedium displayed allopatric characters associated to a tendancy of genome reduction suggesting a specialization process. Considering its relatedness with Brucella, this specialization might be a commitment toward pathogenic life-style that could be driven by technological selective pressure related medical and industrial technologies.

Ochrobactrum daejeonense sp. nov., a nitrate-reducing bacterium isolated from sludge of a leachate treatment plant

A Gram-reaction-negative, non-spore-forming, rod-shaped, aerobic bacterial strain, designated MJ11(T), was isolated from sludge of a leachate treatment plant in Daejeon, South Korea, and was characterized taxonomically by using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that strain MJ11(T) belonged to the family Brucellaceae, class Alphaproteobacteria, and was most closely related to Ochrobactrum ciceri Ca-34(T) (97.9 % sequence similarity) and Ochrobactrum pituitosum CCUG 50899(T) (96.4 %). Comparative sequence analyses of the additional phylogenetic marker genes dnaK, groEL and gyrB confirmed the affiliation of strain MJ11(T) to the genus Ochrobactrum. The G+C content of the genomic DNA of strain MJ11(T) was 59.3 mol%. The detection of a quinone system with ubiquinone Q-10 as the predominant respiratory lipoquinone, a fatty acid profile with C(18 : 1)ω7c (62.6 %) and C(19 : 0) cyclo ω8c (14.2 %) as the major components, a polar lipid profile with phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, phosphatidylmonomethylethanolamine, diphosphatidylglycerol and unknown aminolipids AL1 and AL2 as major polar lipids and spermidine and putrescine as the predominant polyamines also supported the affiliation of strain MJ11(T) to the genus Ochrobactrum. The DNA-DNA relatedness between strain MJ11(T) and Ochrobactrum ciceri DSM 22292(T) was 29 ± 7 %, clearly showing that the isolate constitutes a new genospecies. Strain MJ11(T) could be clearly differentiated from its closest neighbours on the basis of its phenotypic, genotypic and chemotaxonomic features. Therefore, strain MJ11(T) represents a novel species of the genus Ochrobactrum, for which the name Ochrobactrum daejeonense sp. nov. is proposed. The type strain is MJ11(T) ( = KCTC 22458(T) = JCM 16234(T)).

Ochrobactrum pecoris sp. nov., isolated from farm animals

Two Gram-negative, rod-shaped, non-spore-forming strains, designated 08RB2639(T) and 08RB2781-1, were isolated from a sheep (Ovis aries) and a domestic boar (Sus scrofa domestica), respectively. By 16S rRNA gene sequencing, the isolates revealed identical sequences and were shown to belong to the Alphaproteobacteria. They exhibited 97.8 % 16S rRNA gene sequence similarity with Ochrobactrum rhizosphaerae PR17(T), O. pituitosum CCUG 50899(T), O. tritici SCII24(T) and O. haematophilum CCUG 38531(T) and 97.4 % sequence similarity with O. cytisi ESC1(T), O. anthropi LMG 3331(T) and O. lupini LUP21(T). The recA gene sequences of the two isolates showed only minor differences (99.5 % recA sequence similarity), and strain 08RB2639(T) exhibited the highest recA sequence similarity with Ochrobactrum intermedium CCUG 24694(T) (91.3 %). The quinone system was ubiquinone Q-10, with minor amounts of Q-9 and Q-11, the major polyamines were spermidine, putrescine and sym-homospermidine and the major lipids were phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and phosphatidylcholine, with moderate amounts of the Ochrobactrum-specific unidentified aminolipid AL2. The major fatty acids (>20 %) were C₁₈:₁ω7c and C₁₉:₀ cyclo ω8c. These traits were in excellent agreement with the assignment of the isolates to the genus Ochrobactrum. DNA-DNA relatedness and physiological and biochemical tests allowed genotypic and phenotypic differentiation from other members of the genus Ochrobactrum. Hence, it is concluded that the isolates represent a novel species, for which the name Ochrobactrum pecoris sp. nov. is proposed (type strain 08RB2639(T)  = DSM 23868(T)  = CCUG 60088(T)  = CCM 7822(T)).

Camelimonas lactis gen. nov., sp. nov., isolated from the milk of camels

Three strains of Gram-negative, rod-shaped, non-spore-forming bacteria (M 2040T, M 1973 and M 1878-SK2), isolated from milk of camels at a camel-milk production farm in the United Arab Emirates, were investigated for their taxonomic allocation. On the basis of 16S rRNA gene sequence similarities, all three strains were shown to belong to the Alphaproteobacteria and were most closely related to Chelatococcus asaccharovorans and Chelatococcus daeguensis (95.1 and 95.2 % sequence similarity to the respective type strains). meso-Diaminopimelic acid was detected as the characteristic peptidoglycan diamino acid. The predominant compound in the polyamine pattern was spermidine, and sym-homospermidine was not detectable. The quinone system was ubiquinone Q-10. The polar lipid profile included the major compounds phosphatidylcholine and diphosphatidylglycerol and moderate amounts of phosphatidylethanolamine, phosphatidylglycerol, an unidentified glycolipid and two unidentified aminolipids. Minor lipids were also detected. The major fatty acid profile, consisting of C19 : 0 cyclo ω8c and C18 : 1 ω7c, with C18 : 0 3-OH as the major hydroxylated fatty acid, was similar to those of the genus Chelatococcus. The results of DNA–DNA hybridization experiments and physiological and biochemical tests allowed both genotypic and phenotypic differentiation of the isolates from described Chelatococcus species. Isolates M 2040T, M 1973 and M 1878-SK2 were closely related on the basis of DNA–DNA reassociation and therefore represent a single novel species. In summary, low 16S rRNA gene sequence similarities of 95 % with Chelatococcus asaccharovorans and marked differences in polar lipid profiles as well as in polyamine patterns support the description of a novel genus and species to accommodate these strains, for which the name Camelimonas lactis gen. nov., sp. nov. is proposed. The type strain of Camelimonas lactis is M 2040T (=CCUG 58638T =CCM 7696T).

Ochrobactrum ciceri sp. nov., isolated from nodules of Cicer arietinum

A Gram-staining-negative, aerobic, rod-shaped, non-spore-forming bacterial strain, Ca-34(T), was isolated from nodules of chickpea (Cicer arietinum) in Pakistan and studied for its taxonomic affiliation. The almost full-length 16S rRNA gene sequence showed highest similarities to those of strains of the genus Ochrobactrum. Based on results of MALDI-TOF MS and 16S rRNA gene sequence similarity (98.6 %), strain Ca-34(T) and Ochrobactrum intermedium LMG 3301(T) are phylogenetic neighbours; the two strains shared DNA-DNA relatedness of 64 %. The fatty acid profile [predominantly C(18 : 1)omega7c (67.7 %) and C(19 : 0) cyclo omega8c (19.6 %)] also supported the genus affiliation. Metabolically, strain Ca-34(T) differed from other type strains of Ochrobactrum in many reactions and from all type strains in testing positive for gelatin hydrolysis and in testing negative for assimilation of alaninamide and l-threonine. Based on phenotypic and genotypic data, we conclude that strain Ca-34(T) represents a novel species, for which we propose the name Ochrobactrum ciceri sp. nov. (type strain Ca-34(T) =DSM 22292(T) =CCUG 57879(T)).

Paenochrobactrum gallinarii gen. nov., sp. nov., isolated from air of a duck barn, and reclassification of Pseudochrobactrum glaciei as Paenochrobactrum glaciei comb. nov

A Gram-negative, rod-shaped, oxidase-positive, non-spore-forming, non-motile bacterium (Sa25(T)) was isolated from air of a duck barn. 16S rRNA gene and recA sequence analyses clearly placed the isolate in the vicinity of the Brucella-Ochrobactrum-Pseudochrobactrum group, with the closest relative being Pseudochrobactrum glaciei KMM 3858(T). This allocation was confirmed by analyses of the quinone system (ubiquinone Q-10), fatty acid data (major fatty acids C(18 : 1)omega7c and C(19 : 0) cyclo omega8c) and polar lipid profile (major components diphosphatidylglycerol, phosphatidylmonomethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and unknown aminolipid AL1; moderate amounts of three unknown polar lipids, L1-L3, an unknown aminolipid and an unknown aminophospholipid APL2). The polyamine pattern of Sa25(T) exhibited the major compound putrescine and moderate amounts of spermidine; a similar polyamine pattern with the major compound putrescine was also detected in Pseudochrobactrum glaciei KMM 3858(T). DNA-DNA hybridization of strain Sa25(T) with Pseudochrobactrum glaciei KMM 3858(T) and the type strains of the other Pseudochrobactrum species showed values ranging from 50.3 to 24.8 %, and physiological and biochemical data clearly differentiated this isolate from the described Pseudochrobactrum species. Since Sa25(T) and Pseudochrobactrum glaciei KMM 3858(T) form a distinct lineage in the 16S rRNA gene sequence-based phylogenetic tree, and this separate position is supported by unique characteristics of their polyamine patterns and polar lipid profiles, we propose the novel genus Paenochrobactrum gen. nov., with the type species Paenochrobactrum gallinarii sp. nov. (type strain Sa25(T) =CCUG 57736(T) =CCM 7656(T)) and the reclassification of Pseudochrobactrum glaciei as Paenochrobactrum glaciei comb. nov. (type strain Pi26(T) =KMM 3858(T) =NRIC 0733(T) =JCM 15115(T)).