Unraveling the mechanism of sulfur nutrition in pigeonpea inoculated with sulfur-oxidizing bacteria

An investigation was carried out to understand the mechanism(s) involved in the uptake of sulfur (S) as sulfate in pigeonpea following single inoculation of two sulfur-oxidizing bacteria (SOB), Stenotrophomonas maltophilia and Stenotrophomonas pavanii in the treatments amended with either elemental sulfur (S0) or sulfate (S6). Colonization potential and biofilm formation were analyzed through confocal laser scanning microscope (CLSM) and scanning electron microscope (SEM). Furthermore, the effect of seed inoculation on root architecture, expression of genes involved in sulfur oxidation (sox) in bacterial inoculants, and genes involved in sulfate transport in pigeonpea (PpSULTR) were analyzed to correlate with the higher uptake of S in roots and shoots of pigeonpea. Both the SOB exhibited a good colonization potential and biofilm formation on the roots of pigeonpea. Among the 11 sox genes targeted in rhizosphere of pigeonpea, expression was achieved for seven genes, which showed 2-fold increase in treatments inoculated with S. maltophilia and amended with either S6 or S0. The inoculation of S. maltophilia and amendment of S0 led to increased expression of PpSULTR genes by several folds in roots. The inoculation of SOB had a significant influence on non-enzymatic (osmolytes like proline) and enzymatic (PAL, peroxidase, superoxide dismutase, and catalase) levels. The results revealed a significant increase in sulfur uptake in roots and shoots in treatment inoculated with S. maltophilia and amended with S6. The investigation showed that the SOB-mediated over-expression of PpSULTR genes in roots of pigeonpea and sox genes in the rhizosphere were acting synergistically in facilitating higher uptake and translocation of S in roots and shoots of pigeonpea plants.

Genome insights from the identification of a novel Pandoraea sputorum isolate and its characteristics

In this study, we sequenced a bacteria isolate Pandoraea sp. 892iso isolated from a Phytophthora rubi strain which is an important plant pathogenic oomycete, identified through genome and combined the data with existing genomic data from other 28 the genus of Pandoraea species. Next, we conducted a comparative genomic analysis of the genome structure, evolutionary relationships, and pathogenic characteristics of Pandoraea species. Our results identified Pandoraea sp. 892iso as Pandoraea sputorum at both the genome and gene levels. At the genome level, we carried out phylogenetic analysis of single-copy, gene co-linearity, ANI (average nucleotide identity) and AAI (average amino acid identity) indices, rpoB similarity, MLSA phylogenetic analysis, and genome-to-genome distance calculator calculations to identify the relationship between Pandoraea sp. 892iso and P. sputorum. At the gene level, the quorum sensing genes ppnI and ppnR and the OXA-159 gene were assessed. It is speculated that Pandoraea sp. 892iso is the endosymbiont of the Oomycetes strain of Phytophthora rubi.

Novel sulphur-oxidizing bacteria consummate sulphur deficiency in oil seed crop

Plants absorb sulphate, the oxidized form of elemental sulphur (S°), from soil. Sulphur-oxidizing bacteria play a key role in transformation of sulphur in soil. Oil seed crops require high amount of sulphur and it plays an important role in the formation of proteins, vitamins and enzymes. It increases yield, oil content and protein content in oil seed crops. Sulphur is the important constituent of amino acids, viz. methionine, cystine, and cysteine. It necessitates various enzymatic, metabolic processes such as photosynthesis and nitrogen fixation. In the last few years, the prominence of sulphur in oil seed crop nutrition has been accepted as widespread occurrence of its inadequacy in agricultural soil. Approximately 41% of Indian soil is deficient in sulphur. The soil microbial population is the major enforcement behind sulphur transformation. They mineralize, immobilize, oxidize and reduce the elemental and other reduced forms of sulphur. The main step in transformation is oxidation carried out by microorganisms to convert sulphur into sulphate. The chemolithotrophic bacteria belonging to genus Thiobacillus are of primary importance; there are heterotrophic bacteria also which can oxidize sulphur in soil. The pH reduction at the time of oxidation helps in mineralization and absorption of other essential nutrients also. This property of sulphur-oxidizing bacteria (SOB) shows their potential to be used as bioinoculants. Bioformulations prepared using carrier-based formulations, immobilization, biostimulation, etc., are sustainable forms of fertilizers. These SOB inoculants can be used to increase the fertility and sulphate production in soil.

Comparative Genomics of Pandoraea, a Genus Enriched in Xenobiotic Biodegradation and Metabolism

Comparative analysis of partial gyrB, recA, and gltB gene sequences of 84 Pandoraea reference strains and field isolates revealed several clusters that included no taxonomic reference strains. The gyrB, recA, and gltB phylogenetic trees were used to select 27 strains for whole-genome sequence analysis and for a comparative genomics study that also included 41 publicly available Pandoraea genome sequences. The phylogenomic analyses included a Genome BLAST Distance Phylogeny approach to calculate pairwise digital DNA–DNA hybridization values and their confidence intervals, average nucleotide identity analyses using the OrthoANIu algorithm, and a whole-genome phylogeny reconstruction based on 107 single-copy core genes using bcgTree. These analyses, along with subsequent chemotaxonomic and traditional phenotypic analyses, revealed the presence of 17 novel Pandoraea species among the strains analyzed, and allowed the identification of several unclassified Pandoraea strains reported in the literature. The genus Pandoraea has an open pan genome that includes many orthogroups in the ‘Xenobiotics biodegradation and metabolism’ KEGG pathway, which likely explains the enrichment of these species in polluted soils and participation in the biodegradation of complex organic substances. We propose to formally classify the 17 novel Pandoraea species as P. anapnoica sp. nov. (type strain LMG 31117^T = CCUG 73385^T), P. anhela sp. nov. (type strain LMG 31108^T = CCUG 73386^T), P. aquatica sp. nov. (type strain LMG 31011^T = CCUG 73384^T), P. bronchicola sp. nov. (type strain LMG 20603^T = ATCC BAA-110^T), P. capi sp. nov. (type strain LMG 20602^T = ATCC BAA-109^T), P. captiosa sp. nov. (type strain LMG 31118^T = CCUG 73387^T), P. cepalis sp. nov. (type strain LMG 31106^T = CCUG 39680^T), P. commovens sp. nov. (type strain LMG 31010^T = CCUG 73378^T), P. communis sp. nov. (type strain LMG 31110^T = CCUG 73383^T), P. eparura sp. nov. (type strain LMG 31012^T = CCUG 73380^T), P. horticolens sp. nov. (type strain LMG 31112^T = CCUG 73379^T), P. iniqua sp. nov. (type strain LMG 31009^T = CCUG 73377^T), P. morbifera sp. nov. (type strain LMG 31116^T = CCUG 73389^T), P. nosoerga sp. nov. (type strain LMG 31109^T = CCUG 73390^T), P. pneumonica sp. nov. (type strain LMG 31114^T = CCUG 73388^T), P. soli sp. nov. (type strain LMG 31014^T = CCUG 73382^T), and P. terrigena sp. nov. (type strain LMG 31013^T = CCUG 73381^T).

Pneumonia due to Pandoraea Apista after evacuation of traumatic intracranial hematomas:a case report and literature review

Background

Pandoraea species is a newly described genus, which is multidrug resistant and difficult to identify. Clinical isolates are mostly cultured from cystic fibrosis (CF) patients. CF is a rare disease in China, which makes Pandoraea a total stranger to Chinese physicians. Pandoraea genus is reported as an emerging pathogen in CF patients in most cases. However, there are few pieces of evidence that confirm Pandoraea can be more virulent in non-CF patients. The pathogenicity of Pandoraea genus is poorly understood, as well as its treatment. The incidence of Pandoraea induced infection in non-CF patients may be underestimated and it’s important to identify and understand these organisms.

Case presentation

We report a 44-years-old man who suffered from pneumonia and died eventually. Before his condition deteriorated, a Gram-negative bacilli was cultured from his sputum and identified as Pandoraea Apista by matrix-assisted laser desorption ionization–time-of-flight mass spectrometry (MALDI-TOF MS).

Conclusion

Pandoraea spp. is an emerging opportunistic pathogen. The incidences of Pandoraea related infection in non-CF patients may be underestimated due to the difficulty of identification. All strains of Pandoraea show multi-drug resistance and highly variable susceptibility. To better treatment, species-level identification and antibiotic susceptibility test are necessary.

The RSc0454-Encoded FAD-Linked Oxidase Is Indispensable for Pathogenicity in Ralstonia solanacearum GMI1000

Ralstonia solanacearum is the causal agent of bacterial wilt disease. Here, we report that a large FAD-linked oxidase encoded by RSc0454 in GMI1000 is required for pathogenicity. The FAD-linked oxidase encoded by RSc0454 is composed of 1,345 amino acids, including DUF3683, lactate dehydrogenase (LDH), and succinate dehydrogenase (SDH) domains. The RSc0454 protein showed both LDH and SDH activities. To investigate its role in pathogenicity, a deletion mutant of the RSc0454 gene was constructed in GMI1000, which was impaired in its ability to cause bacterial wilt disease in tomato. A single DUF3683, LDH, or SDH domain was insufficient to restore bacterial pathogenicity. Mutagenesis of the RSc0454 gene did not affect growth rate but caused cell aggregation at the bottom of the liquid nutrient medium, which was reversed by exogenous applications of lactate, fumarate, pyruvate, and succinate. qRT-PCR and promoter LacZ fusion experiments demonstrated that RSc0454 gene transcription was induced by lactate and fumarate (both substrates of LDH). Compared with the downregulation of the succinate dehydrogenase gene sdhBADC and the lactate dehydrogenase gene ldh, RSc0454 gene transcription was enhanced in planta. This suggests that the oxidase encoded by RSc0454 was involved in a redox balance, which is in line with the different living conditions of R. solanacearum.

Genomic and proteomic analysis of lignin degrading and polyhydroxyalkanoate accumulating β-proteobacterium Pandoraea sp. ISTKB

BACKGROUND

Lignin is a major component of plant biomass and is recalcitrant to degradation due to its complex and heterogeneous aromatic structure. The biomass-based research mainly focuses on polysaccharides component of biomass and lignin is discarded as waste with very limited usage. The sustainability and success of plant polysaccharide-based biorefinery can be possible if lignin is utilized in improved ways and with minimal waste generation. Discovering new microbial strains and understanding their enzyme system for lignin degradation are necessary for its conversion into fuel and chemicals. The Pandoraea sp. ISTKB was previously characterized for lignin degradation and successfully applied for pretreatment of sugarcane bagasse and polyhydroxyalkanoate (PHA) production. In this study, genomic analysis and proteomics on aromatic polymer kraft lignin and vanillic acid are performed to find the important enzymes for polymer utilization.

RESULTS

Genomic analysis of Pandoraea sp. ISTKB revealed the presence of strong lignin degradation machinery and identified various candidate genes responsible for lignin degradation and PHA production. We also applied label-free quantitative proteomic approach to identify the expression profile on monoaromatic compound vanillic acid (VA) and polyaromatic kraft lignin (KL). Genomic and proteomic analysis simultaneously discovered Dyp-type peroxidase, peroxidases, glycolate oxidase, aldehyde oxidase, GMC oxidoreductase, laccases, quinone oxidoreductase, dioxygenases, monooxygenases, glutathione-dependent etherases, dehydrogenases, reductases, and methyltransferases and various other recently reported enzyme systems such as superoxide dismutases or catalase-peroxidase for lignin degradation. A strong stress response and detoxification mechanism was discovered. The two important gene clusters for lignin degradation and three PHA polymerase spanning gene clusters were identified and all the clusters were functionally active on KL-VA.

CONCLUSIONS

The unusual aerobic '-CoA'-mediated degradation pathway of phenylacetate and benzoate (reported only in 16 and 4-5% of total sequenced bacterial genomes), peroxidase-accessory enzyme system, and fenton chemistry based are the major pathways observed for lignin degradation. Both ortho and meta ring cleavage pathways for aromatic compound degradation were observed in expression profile. Genomic and proteomic approaches provided validation to this strain's robust machinery for the metabolism of recalcitrant compounds and PHA production and provide an opportunity to target important enzymes for lignin valorization in future.

Parvibium lacunae gen. nov., sp. nov., a new member of the family Alcaligenaceae isolated from a freshwater pond

A bacterial strain designated KMB9^T was isolated from a freshwater pond in Taiwan and characterized using a polyphasic taxonomy approach. Cells of strain KMB9^T were Gram-stain-negative, aerobic, poly-β-hydroxybutyrate-accumulating, motile by means of a monopolar flagellum, non-spore-forming and rods surrounded by a thick capsule and forming white-coloured colonies. Growth occurred at 20-40 °C (optimum, 25-37 °C), at pH 6.5-7.5 (optimum, pH 7.0) and with 0-0.5 % NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene and four housekeeping gene sequences (recA, rpoA, rpoB and atpD) showed that strain KMB9^T forms a distinct phyletic line within the family Alcaligenaceae, and the levels of 16S rRNA gene sequence similarity to its closest relatives with validly published names were less than 93.3 %. The predominant fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c. The major isoprenoid quinone was Q-8. The major polyamine was putrescine. The polar lipid profile revealed the presence of phosphatidylethanolamine, phosphatidylglycerol and several uncharacterized aminophospholipids, aminolipids, phospholipids and lipids. The genomic DNA G+C content of strain KMB9^T was 54.5 mol%. On the basis of the genotypic and phenotypic data, strain KMB9^T represents a novel species of a new genus in the family Alcaligenaceae, for which the name Parvibium lacunae gen. nov., sp. nov. is proposed. The type strain is KMB9^T (=BCRC 81053^T=LMG 30055^T=KCTC 52814^T).

Genome of Ca. Pandoraea novymonadis, an Endosymbiotic Bacterium of the Trypanosomatid Novymonas esmeraldas

We have sequenced, annotated, and analyzed the genome of Ca. Pandoraea novymonadis, a recently described bacterial endosymbiont of the trypanosomatid Novymonas esmeraldas. When compared with genomes of its free-living relatives, it has all the hallmarks of the endosymbionts’ genomes, such as significantly reduced size, extensive gene loss, low GC content, numerous gene rearrangements, and low codon usage bias. In addition, Ca. P. novymonadis lacks mobile elements, has a strikingly low number of pseudogenes, and almost all genes are single copied. This suggests that it already passed the intensive period of host adaptation, which still can be observed in the genome of Polynucleobacter necessarius, a certainly recent endosymbiont. Phylogenetically, Ca. P. novymonadis is more related to P. necessarius, an intracytoplasmic bacterium of free-living ciliates, than to Ca. Kinetoplastibacterium spp., the only other known endosymbionts of trypanosomatid flagellates. As judged by the extent of the overall genome reduction and the loss of particular metabolic abilities correlating with the increasing dependence of the symbiont on its host, Ca. P. novymonadis occupies an intermediate position P. necessarius and Ca. Kinetoplastibacterium spp. We conclude that the relationships between Ca. P. novymonadis and N. esmeraldas are well-established, although not as fine-tuned as in the case of Strigomonadinae and their endosymbionts.

Phylogeny and polycyclic aromatic hydrocarbons degradation potential of bacteria isolated from crude oil-contaminated site

This study employed the use of 16S rRNA gene sequence analysis to identify three of four native bacterial strains isolated from crude oil-contaminated site in Poza Rica, Veracruz, Mexico. The identified bacteria were Ochrobactrum intermedium, Pandoraea pnomenusa and Ochrobactrum sp., but SA2-09 strain was not identified. The ability of the isolates to degrade polycyclic aromatic hydrocarbons (PAHs) was evaluated at 31.61 and 54.52 mg/kg PAHs in soil, when used as crude oil in soil microcosm during 80 days of incubation at 30°C. The results demonstrated that O. intermedium biodegraded many PAHs, including the high molecular weight (HMW) PAHs fluoranthene (100% equivalent 0.24 mg/kg), benzo [b] fluoranthene (81.8% equal 0.18 mg/kg), Benzo[a]pyrene (87.0%, 0.20 mg/kg) and Benzo[g,h,i]perylene (52.7%, 0.39 mg/kg). P. pnomenusa had a degradation profile of HMW PAHs, which was similar to O. intermedium, while Ochrobactrum sp. and the strain SA-09 exhibited lower degradation rates of HMW.

Limnobacter humi sp. nov., a thiosulfate-oxidizing, heterotrophic bacterium isolated from humus soil, and emended description of the genus Limnobacter Spring et al. 2001

Three Gram-negative, strictly aerobic, chemolithoheterotrophic bacterial strains, designated UCM-30, UCM-33, and UCM-39^T, were isolated in South Korea. Based on their 16S rRNA gene sequences, the three isolated strains were found to be similar to Limnobacter thiooxidans CS-K2^T (97.41-97.68%), Limnobacter litoralis KP1-19^T (95.55-95.76%), and various genera belonging to the class Betaproteobacteria (90.34-93.34%). DNA-DNA hybridization showed 79.3-83.9% similarity between the genomic DNA of UCM-39^T, UCM-30, and UCM-33, while the sequence similarity between UCM-39^T and L. thiooxidans KACC 13837T or L. litoralis LMG 24869T was 23.7% and 18.6%, respectively. The DNA G+C content of UCM 39T was 59.7 mol%, the major ubiquinone was Q-8, and the optimal oxidation rate was observed at 10 mM thiosulfate. The major fatty acids (≥ 10%) were summed features 3 (C_16:1 ω7c and/or C_16:1 ω6c) and 8 (C_18:1 ω7c and/or C_18:1 ω6c), and C_16:0. The major polar lipids (diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylglycerol) were found in all members of genus Limnobacter. Based on phenotypic, physiological, and phylogenetic analyses, the UCM-39T strain was found to be significantly distinct to represent a novel species affiliated to the genus Limnobacter. We propose to name it Limnobacter humi sp. nov. with the type strain UCM-39^T (=KACC 18574^T =NBRC 111650^T).

Characterization and Comparative Overview of Complete Sequences of the First Plasmids of Pandoraea across Clinical and Non-clinical Strains

To date, information on plasmid analysis in Pandoraea spp. is scarce. To address the gap of knowledge on this, the complete sequences of eight plasmids from Pandoraea spp. namely Pandoraea faecigallinarum DSM 23572^T (pPF72-1, pPF72-2), Pandoraea oxalativorans DSM 23570^T (pPO70-1, pPO70-2, pPO70-3, pPO70-4), Pandoraea vervacti NS15 (pPV15) and Pandoraea apista DSM 16535^T (pPA35) were studied for the first time in this study. The information on plasmid sequences in Pandoraea spp. is useful as the sequences did not match any known plasmid sequence deposited in public databases. Replication genes were not identified in some plasmids, a situation that has led to the possibility of host interaction involvement. Some plasmids were also void of par genes and intriguingly, repA gene was also not discovered in these plasmids. This further leads to the hypothesis of host-plasmid interaction. Plasmid stabilization/stability protein-encoding genes were observed in some plasmids but were not established for participating in plasmid segregation. Toxin-antitoxin systems MazEF, VapBC, RelBE, YgiT-MqsR, HigBA, and ParDE were identified across the plasmids and their presence would improve plasmid maintenance. Conjugation genes were identified portraying the conjugation ability amongst Pandoraea plasmids. Additionally, we found a shared region amongst some of the plasmids that consists of conjugation genes. The identification of genes involved in replication, segregation, toxin-antitoxin systems and conjugation, would aid the design of drugs to prevent the survival or transmission of plasmids carrying pathogenic properties. Additionally, genes conferring virulence and antibiotic resistance were identified amongst the plasmids. The observed features in the plasmids shed light on the Pandoraea spp. as opportunistic pathogens.

Piscinibacterium candidicorallinum gen. nov., sp. nov., a member of the order Burkholderiales isolated from a fish pond

A bacterial strain designated LYH-15T was isolated from a freshwater fish pond in Taiwan and characterized using a polyphasic taxonomy approach. Cells of LYH-15T were Gram-staining-negative, aerobic, motile by means of a single polar flagellum, poly-β-hydroxybutyrate-containing, non-spore forming, straight rods and formed light-coral-colored colonies. Growth occurred at 15-40 °C (optimum, 30 °C), at pH 5.0-9.0 (optimum, pH 7.0) and with 0-0.5 % NaCl (optimum, 0 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that LYH-15T forms a distinct phyletic line within the order Burkholderiales, with less than 94 % sequence similarity to its closest relatives with validly published names. The predominant fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c. The major isoprenoid quinone was Q-8 and the DNA G+C content was 63.8 mol%. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several uncharacterized lipids. The major polyamines were 2-hydroxyputrescine and putrescine. On the basis of the genotypic and phenotypic data, LYH-15T represents a novel species of a new genus in the order Burkholderiales, for which the name Piscinibacterium candidicorallinum gen. nov., sp. nov. is proposed. The type strain is LYH-15T (=BCRC 80969T=LMG 29480T=KCTC 52168T).

Pandoraea terrae sp. nov., isolated from forest soil, and emended description of the genus Pandoraea Coenye et al. 2000

A Gram-staining-negative, facultatively aerobic, white-colony-forming bacterium, designated strain SE-S21T, was isolated from forest soil of Jeju Island in Korea. Cells were motile rods with a single polar flagellum, showing catalase- and oxidase-positive reactions. Growth was observed at 10-40 °C (optimum, 30 °C), pH 4.0-10.0 (optimum, pH 7.0-7.5) and with 0-4.0 % (w/v) NaCl (optimum, 0-2 %). Only ubiquinone-8 was detected as the isoprenoid quinone, and C16 : 0, C17 : 0 cyclo, C19 : 1ω8c cyclo and summed feature 2 (comprising C12 : 0 aldehyde and/or unknown) were found to be the major fatty acids. Phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, an unknown aminophospholipid, an unknown aminolipid and an unknown lipid were detected as the major polar lipids. Putrescine and 2-hydroxyputrescine were the predominant polyamines. The DNA G+C content was 61.0 mol%. Phylogenetic analyses based on 16S rRNA and DNA gyrase B gene sequences revealed that strain SE-S21T formed a phyletic lineage within the genus Pandoraea. Strain SE-S21T was most closely related to Pandoraea faecigallinarum KOxT and Pandoraea pnomenusa CCUG 38742T with 98.8 % and 98.7 % 16S rRNA gene sequence similarities, respectively. However, the DNA-DNA relatedness values between strain SE-S21T and the type strains of P. faecigallinarum and P. pnomenusa were 26.6±5.7 % and 20.5±3.7 %, respectively. On the basis of phenotypic, chemotaxonomic and molecular features, strain SE-S21T clearly represents a novel species of the genus Pandoraea, for which the name Pandoraea terrae sp. nov. is proposed. The type strain is SE-S21T (=KACC 18127T=JCM 30137T). An emended description of the genus Pandoraea is also proposed.

Novel Trypanosomatid-Bacterium Association: Evolution of Endosymbiosis in Action

We describe a novel symbiotic association between a kinetoplastid protist, Novymonas esmeraldas gen. nov., sp. nov., and an intracytoplasmic bacterium, “Candidatus Pandoraea novymonadis” sp. nov., discovered as a result of a broad-scale survey of insect trypanosomatid biodiversity in Ecuador. We characterize this association by describing the morphology of both organisms, as well as their interactions, and by establishing their phylogenetic affinities. Importantly, neither partner is closely related to other known organisms previously implicated in eukaryote-bacterial symbiosis. This symbiotic association seems to be relatively recent, as the host does not exert a stringent control over the number of bacteria harbored in its cytoplasm. We argue that this unique relationship may represent a suitable model for studying the initial stages of establishment of endosymbiosis between a single-cellular eukaryote and a prokaryote. Based on phylogenetic analyses, Novymonas could be considered a proxy for the insect-only ancestor of the dixenous genus Leishmania and shed light on the origin of the two-host life cycle within the subfamily Leishmaniinae.

The parasitic trypanosomatid protist Novymonas esmeraldas gen. nov., sp. nov. entered into endosymbiosis with the bacterium “Ca. Pandoraea novymonadis” sp. nov. This novel and rather unstable interaction shows several signs of relatively recent establishment, qualifying it as a potentially unique transient stage in the increasingly complex range of eukaryotic-prokaryotic relationships.

Mycoavidus cysteinexigens gen. nov., sp. nov., an endohyphal bacterium isolated from a soil isolate of the fungus Mortierella elongata

An endohyphal bacterium (strain B1-EBT) living in association with the fungus Mortierella elongata FMR23-6 I-B1 was isolated from a fungal cell homogenate and studied for its taxonomic allocation. Cells were Gram-stain-negative, rod-shaped, non-spore-forming, non-motile, and negative for oxidase and catalase. Strain B1-EBT required cysteine for growth and grew at temperatures between 4 and 35 °C. A comparative analysis of 16S rRNA gene sequences revealed that strain B1-EBT forms a distinct clade in the family Burkholderiaceae, encompassing a group of endosymbionts associated with several soil isolates of M. elongata. The most closely related genus is 'Candidatus Glomeribacter gigasporarum', an endosymbiont of the arbuscular mycorrhizal fungus Gigaspora margarita. The major cellular fatty acids of strain B1-EBT were C16 : 0, summed feature 3 (C16 : 1ω7c and C16 : 1ω6c) and summed feature 8 (C18 : 1ω7c or C18 : 1ω6c). Ubiquinone Q-8 was the only quinone detected. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unknown aminophospholipid and two unknown aminolipids. The DNA G+C content was 49.8 mol%. On the basis of phenotypic, chemotaxonomic, and phylogenetic characteristics, strain B1-EBT represents a novel genus and novel species in the family Burkholderiaceae, for which the name Mycoavidus cysteinexigens gen. nov., sp. nov. is proposed. The type strain is B1-EBT ( = JCM 30646T = LMG 28693T = NBRC 110909T).

Complete genome sequence of Pandoraea oxalativorans DSM 23570(T), an oxalate metabolizing soil bacterium

Pandoraea oxalativorans DSM 23570(T) is an oxalate-degrading bacterium that was originally isolated from soil litter near to oxalate-producing plant of the genus Oxalis. Here, we report the first complete genome of P. oxalativorans DSM 23570(T) which would allow its potential biotechnological applications to be unravelled.

Epidemic spread of Pandoraea pulmonicola in a cystic fibrosis center

Background

Pandoraea spp. are recently discovered bacteria, mainly recovered from cystic fibrosis (CF) patients, but their epidemiology and clinical significance are not well known. We describe an epidemic spread of Pandoraea pulmonicola from 2009 in our CF center, involving 6 out of 243 CF patients.

Methods

Bacterial identification used amplified ribosomal DNA restriction analysis (ARDRA), MALDI-TOF mass spectrometry (MALDI-TOF MS) and 16S rDNA gene sequencing. The clonal link between strains was assessed with pulsed field gel electrophoresis (PFGE) using XbaI. Clinical data were gathered for all patients.

Results

The index case was chronically colonized since 2000. The main hypothesis for this bacterial spread was a droplet cross-transmission, due to preventive measures not being strictly followed. Antibiotic susceptibility testing revealed resistance to beta-lactams, ciprofloxacin and colistin. However, there was susceptibility to trimethoprim-sulfamethoxazole. All patients were chronically colonized with Pseudomonas aeruginosa, and the acquisition of P. pulmonicola resulted in chronic colonization in all patients. Three patients died, and two patients remained clinically stable, whereas one patient had a decline in lung function.

Conclusions

This study, which is the first to describe an epidemic spread of P. pulmonicola, notes the potential transmissibility of this bacterial species and the need for infection control measures.

Complete genome of Pandoraea pnomenusa RB-38, an oxalotrophic bacterium isolated from municipal solid waste landfill site

Pandoraea pnomenusa RB-38 is a bacterium isolated from a former sanitary landfill site. Here, we present the complete genome of P. pnomenusa RB38 in which an oxalate utilization pathway was identified. The genome analysis suggested the potential of this strain as an effective biocontrol agent against oxalate-producing phytopathogens.

Pandoraea oxalativorans sp. nov., Pandoraea faecigallinarum sp. nov. and Pandoraea vervacti sp. nov., isolated from oxalate-enriched culture

Five isolates, designated TA2, TA4, TA25T, KOxT and NS15T were isolated in previous studies by enrichment in mineral medium with potassium oxalate as the sole carbon source and were characterized using a polyphasic approach. The isolates were Gram-reaction-negative, aerobic, non-spore-forming rods. Phylogenetic analyses based on 16S rRNA and DNA gyrase B subunit (gyrB) gene sequences confirmed that the isolates belonged to the genus Pandoraea and were most closely related to Pandoraea sputorum and Pandoraea pnomenusa (97.2–99.7 % 16S rRNA gene sequence similarity). The isolates could be differentiated from their closest relatives on the basis of several phenotypic characteristics. The major cellular fatty acid profiles of the isolates comprised C16 : 0, C18 : 1ω7c, C17 : 0 cyclo and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). On the basis of DNA–DNA hybridization studies and phylogenetic analyses, the isolates represent three novel species within the genus Pandoraea, for which the names Pandoraea oxalativorans sp. nov. (TA25T  = NBRC 106091T  = CCM 7677T  = DSM 23570T), Pandoraea faecigallinarum sp. nov. (KOxT  = NBRC 106092T  = CCM 2766T  = DSM 23572T) and Pandoraea vervacti sp. nov. (NS15T  = NBRC 106088T  = CCM 7667T  = DSM 23571T) are proposed.