Characterization and Genome Analysis of the Delftia lacustris Strain LzhVag01 Isolated from Vaginal Discharge.

Delftia has been separated from freshwater, sludge, and soil and has emerged as a novel opportunistic pathogen in the female vagina. However, the genomic characteristics, pathogenicity, and biotechnological properties still need to be comprehensively investigated. In this study, a Delftia strain was isolated from the vaginal discharge of a 43-year-old female with histologically confirmed cervical intraepithelial neoplasm (CIN III), followed by whole-genome sequencing. Phylogenetic analysis and average nucleotide identity (ANI) analysis demonstrated that it belongs to Delftia lacustris, named D. lacustris strain LzhVag01. LzhVag01 was sensitive to ß-lactams, macrolides, and tetracyclines but exhibited resistance to lincoamines, nitroimidazoles, aminoglycosides, and fluoroquinolones. Its genome is a single, circular chromosome of 6,740,460 bp with an average GC content of 66.59%. Whole-genome analysis identified 16 antibiotic resistance-related genes, which match the antimicrobial susceptibility profile of this strain, and 11 potential virulence genes. These pathogenic factors may contribute to its colonization in the vaginal environment and its adaptation and accelerate the progression of cervical cancer. This study sequenced and characterized the whole-genome of Delftia lacustris isolated from vaginal discharge, which provides investigators and clinicians with valuable insights into this uncommon species.

Potential biodegradation of phenanthrene by isolated halotolerant bacterial strains from petroleum oil polluted soil in Yellow River Delta.

The Yellow River Delta (YRD), being close to Shengli Oilfield, is at high risk for petroleum oil pollution. The aim of this study was to isolate halotolerant phenanthrene (PHE) degrading bacteria for dealing with this contaminates in salinity environment. Two bacterial strains assigned as FM6-1 and FM8-1 were successfully screened from oil contaminated soil in the YRD. Morphological and molecular analysis suggested that strains FM6-1 and FM8-1 were belonging to Delftia sp. and Achromobacter sp., respectively. Bacterial growth of both strains was not dependent on NaCl, however, grew well under extensive NaCl concentration. The optimum NaCl concentration for bacterial production of strain FM8-1 was 4% (m/v), whereas for strain FM6-1, growth was not affected within 2.5% NaCl. Both strains could use the tested aromatic hydrocarbons (naphthalene, phenanthrene, fluoranthene and pyrene) and aliphatic hydrocarbons (C12, C16, C20 and C32) as sole carbon source. The optimized biodegradation conditions for strain FM6-1 were pH 7, 28 °C and 2% NaCl, for strain FM8-1 were pH 8, 28 °C and 2.5% NaCl. The highest biodegradation rate of strains FM6-1 and FM8-1 was found at 150 mg/L PHE and 200 mg/L, respectively. In addition, strainsFM8-1 showed a superior biodegradation ability to strain FM6-1 at each optimized condition. The PHE biodegradation process by both strains well fitted to first-order kinetic models and the k1 values were calculated to be 0.1974 and 0.1070 per day. Strain FM6-1 metabolized PHE via a "phthalic acid" route, while strain FM8-1 metabolized PHE through the "naphthalene" route. This project not only obtained two halotolerant petroleum hydrocarbon degraders but also provided a promising remediation approach for solving oil pollutants in salinity environments.

Delftia sp. LCW, a strain isolated from a constructed wetland shows novel properties for dimethylphenol isomers degradation.

BACKGROUND: Dimethylphenols (DMP) are toxic compounds with high environmental mobility in water and one of the main constituents of effluents from petro- and carbochemical industry. Over the last few decades, the use of constructed wetlands (CW) has been extended from domestic to industrial wastewater treatments, including petro-carbochemical effluents. In these systems, the main role during the transformation and mineralization of organic pollutants is played by microorganisms. Therefore, understanding the bacterial degradation processes of isolated strains from CWs is an important approach to further improvements of biodegradation processes in these treatment systems. RESULTS: In this study, bacterial isolation from a pilot scale constructed wetland fed with phenols led to the identification of Delftia sp. LCW as a DMP degrading strain. The strain was able to use the o-xylenols 3,4-DMP and 2,3-DMP as sole carbon and energy sources. In addition, 3,4-DMP provided as a co-substrate had an effect on the transformation of other four DMP isomers. Based on the detection of the genes, proteins, and the inferred phylogenetic relationships of the detected genes with other reported functional proteins, we found that the phenol hydroxylase of Delftia sp. LCW is induced by 3,4-DMP and it is responsible for the first oxidation of the aromatic ring of 3,4-, 2,3-, 2,4-, 2,5- and 3,5-DMP. The enzyme may also catalyze both monooxygenation reactions during the degradation of benzene. Proteome data led to the identification of catechol meta cleavage pathway enzymes during the growth on ortho DMP, and validated that cleavage of the aromatic rings of 2,5- and 3,5-DMPs does not result in mineralization. In addition, the tolerance of the strain to high concentrations of DMP, especially to 3,4-DMP was higher than that of other reported microorganisms from activated sludge treating phenols. CONCLUSIONS: LCW strain was able to degraded complex aromatics compounds. DMPs and benzene are reported for the first time to be degraded by a member of Delftia genus. In addition, LCW degraded DMPs with a first oxidation of the aromatic rings by a phenol hydroxylase, followed by a further meta cleavage pathway. The higher resistance to DMP toxicity, the ability to degrade and transform DMP isomers and the origin as a rhizosphere bacterium from wastewater systems, make LCW a suitable candidate to be used in bioremediation of complex DMP mixtures in CWs systems.

Biodegradation of diethyl terephthalate and polyethylene terephthalate by a novel identified degrader Delftia sp. WL-3 and its proposed metabolic pathway.

Polyethylene terephthalate (PET), a synthetic polyester material made of diethyl terephthalate (DET) monomers, is widely used in plastic products of daily life and caused serious pollution to the global environment. Microbial metabolism is the major degradation pathway responsible for DET degradation in natural soil; however, the microbial DET degradation mechanism remains unclear. In this study, the newly isolated strain WL-3, identified as belonging to the genus Delftia, was found to be able to degrade 94% of 5 g l-1 of DET and utilize it as the sole carbon source for growth within 7 days. Furthermore, strain WL-3 was capable of stable DET degradation under a wide range of pH values (6·0-9·0) and temperatures (20-42°C) with the optimal pH and temperature of 7·0 and 30°C respectively. Furthermore, the biochemical pathway of DET degradation by strain WL-3 was proposed based on the identified degradation intermediates. DET is first transformed into terephthalic acid (TPA) by the hydrolysis of two ester bonds, which is subsequently converted to protocatechuic acid (PCA) and further mineralized. SEM observations revealed obvious cracks on the surface of PET film after inoculation of 2 months with strain WL-3, indicating the strain's potential for the bioremediation of PET-contaminated environments. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates that Delftia sp. WL-3 can mineralize completely diethyl terephthalate by biochemical processes. The study reveals the metabolic mechanism of diethyl terephthalate biodegradation. Furthermore, the cracks on the surface of Polyethylene terephthalate film that form upon inoculation with strain WL-3 were observed using SEM. These results highlight the potential of the strain WL-3 in the bioremediation of environments contaminated with Polyethylene terephthalate or diethyl terephthalate.

Delftia tsuruhatensis, an Emergent Opportunistic Healthcare-Associated Pathogen.

Delftia tsuruhatensis, which was first isolated in environmental samples, was rarely associated with human infections. We report on pneumonia caused by D. tsuruhatensis in an infant who underwent cardiac surgery. Retrospective analyses detected 9 other isolates from 8 patients. D. tsuruhatensis is an emergent pathogen, at least for immunocompromised patients.

Delftia rhizosphaerae sp. nov. isolated from the rhizosphere of Cistus ladanifer.

A bacterial strain, designated RA6T, was isolated from the rhizosphere of Cistus ladanifer. Phylogenetic analyses based on 16S rRNA gene sequence placed the isolate into the genus Delftia within a cluster encompassing the type strains of Delftia lacustris, Delftia tsuruhatensis, Delftia acidovorans and Delftia litopenaei, which presented greater than 97 % sequence similarity with respect to strain RA6T. DNA-DNA hybridization studies showed average relatedness ranging from of 11 to 18 % between these species of the genus Delftia and strain RA6T. Catalase and oxidase were positive. Casein was hydrolysed but gelatin and starch were not. Ubiquinone 8 was the major respiratory quinone detected in strain RA6T together with low amounts of ubiquinones 7 and 9. The major fatty acids were those from summed feature 3 (C16 : 1ω7c/C16 : 1 ω6c) and C16 : 0. The predominant polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Phylogenetic, chemotaxonomic and phenotypic analyses showed that strain RA6T should be considered as a representative of a novel species of genus Delftia, for which the name Delftia rhizosphaerae sp. nov. is proposed. The type strain is RA6T (=LMG 29737T= CECT 9171T).

[Isolation and Identification of a Chlorobenzene-degrading Bacterium and Its Degradation Characteristics].

A bacterium strain LW26 which could utilize chlorobenzene (CB) as sole carbon and energy source was isolated from a biotrickling filter reactor treating CB-contaminated off-gas. Based on its morphological and physiological characteristics, as well as the analysis of 16S rRNA gene sequence and Biolog test, the strain LW26 was identified as Delftia tsuruhatensis. To our best knowledge, it is the first time that the strain Delftia tsuruhatensis was applied for CB purification. In this study, the effects of temperature, pH, initial CB concentration and Cl- concentration on the biodegradation were investigated. The results showed that the optimal temperature and pH for CB biodegradation were 25℃ and 7.0,respectively; the maximum CB tolerated concentration for LW26 was as high as 500 mg·L-1; when the concentration of Cl- was above 0.14 mol·L-1, the CB degradation was significantly restrained. The degrading process of the strain LW26 followed the Haldane kinetic model and the maximum specific growth rate and the maximum specific degradation rate were 0.42 h-1 and 2.53 h-1, respectively.GC-MS analysis of the metabolites revealed that CB was firstly converted to o-chlorophenol by strain LW26. Combined with the activity of catechol dioxygenase, it can be speculated that CB was finally mineralized to CO2, or converted to cell biomass after processes of ortho cleavage,dechlorination and oxidation.

A novel Delftia plant symbiont capable of autotrophic methylotrophy.

A facultative methylotrophic bacterium, strain Lp-1, which was isolated from root nodules of lupine (Lupinus polyphyllus L.) on the medium with methanol as a carbon and energy source, exhibited high similarity of the 16S rRNA gene sequences to Delftia strains (94‒99.9%). The cells of Delftia sp. Lp-1 were motile gram-negative rods dividing by binary fission. Predominant fatty acids were C16:0 (34.2%), C16:1ω9 (14.5%), and C18:1ω7c (17.3%). Phosphatidylethanolamine, phosphatidylcholine, and phosphatidylglycerol were the dominant phospholipids. Q8 was the major ubiquinone. Optimal growth occurred at 24‒26°C and pH 7.1‒7.3; growth was inhibited by 1% NaCl. The organism oxidized methanol with the classical methanol dehydrogenase and used the ribulose bisphosphate pathway of C1 metabolism. Analysis of translated amino acid sequence of the large subunit of the MxaF methanol dehydrogenase revealed 85.5‒94% similarity to the sequences of such autotrophic methylotrophs of the class Alphaproteobacteria as Angulomicrobium, Starkeya, and Ancylobacter, indicating the possible acquisition of the mxaF gene via horizontal gene transfer. Delftia sp. Lp-1 (VKM B-3039, DSM 24446), the first methylotrophic member of the genus Delftia, was shown to be a plant symbiont, stimulating plant growth and morphogenesis, increasing the level of photosynthetic pigments and specific leaf weight. It possesses the nifH gene of nitrogen fixation, is capable of phosphate solubilization, synthesis of auxins and siderophores, and is antagonistic to plant pathogenic fungi and bacilli.

Delftia tsuruhatensis WGR-UOM-BT1, a novel rhizobacterium with PGPR properties from Rauwolfia serpentina (L.) Benth. ex Kurz also suppresses fungal phytopathogens by producing a new antibiotic-AMTM.

UNLABELLED: The bacterial strain designated as WGR-UOM-BT1 isolated from rhizosphere of Rauwolfia serpentina exhibited broad-spectrum antifungal activity and also improved early plant growth. Based on morphological, biochemical and 16S rRNA gene sequence analyses, the strain BT1 was identified as Delftia tsuruhatensis (KF727978). Under in vitro conditions, the strain BT1 suppressed the growth of wide range of fungal phytopathogens. Purified antimicrobial metabolite from the strain BT1 was identified as nitrogen-containing heterocyclic compound, 'amino(5-(4-methoxyphenyl)-2-methyl-2-(thiophen-2-yl)-2,3-dihydrofuran-3-yl)methanol' (AMTM), with molecular mass of 340•40 and molecular formula of C17 H19 NO3 S. The strain BT1 was positive for rhizosphere colonization (tomato), IAA production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity and phosphate solubilization. Under laboratory and greenhouse conditions, the strain BT1 promoted plant growth and suppressed foliar and root fungal pathogens of tomato. Therefore, antimicrobial and disease protection properties of strain BT1 could serve as an effective biological control candidate against devastating fungal pathogens of vegetable plants. Besides, the production of IAA, P solubilization and ACC deaminase activity enhance its potential as a biofertilizer and may stabilize the plant performance under fluctuating environmental conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, we reported that Delftia tsuruhatensis WGR-UOM-BT1 strain has the plant growth promotion activities such as rhizosphere colonization (tomato), IAA production, 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity and phosphate solubilization. This bacterial strain was found producing an antimicrobial nitrogen-containing heterocyclic compound identified as 'amino(5-(4-methoxyphenyl)-2-methyl-2-(thiophen-2-yl)-2,3-dihydrofuran-3-yl)methanol' [C17 H19 NO3 S] (AMTM), which is new to the bacterial world.

Characterization and Genomic Analysis of Quinolone-Resistant Delftia sp. 670 Isolated from a Patient Who Died from Severe Pneumonia.

Antibiotic-resistant opportunistic pathogens have become a serious concern in recent decades, as they are increasingly responsible for hospital-acquired infections. Here, we describe quinolone-resistant Delftia sp. strain 670, isolated from the sputum of a patient who died from severe pulmonary infection. The draft genome sequence of this strain was obtained by whole-genome shotgun sequencing, and was subjected to comparative genome analysis. Genome analysis revealed that one critical mutation (Ser83Ile in gyrA) might play a decisive role in quinolone resistance. The genome of Delftia sp. strain 670 contains both type II and type VI secretion systems, which were predicted to contribute to the virulence of the strain. Phylogenetic analysis, assimilation tests, and comparative genome analysis indicated that strain 670 differed from the four known Delftia species, suggesting this strain could represent a novel species. Although the study could not determine the strain 670 as the pathogen led to mortality, our findings also presented the pathogenic potential of Delftia species, and the increasing severity of antibiotic resistance among emerging opportunistic pathogens. The whole genome sequencing and comparative analysis improved our understanding of genome evolution in the genus Delftia, and provides the foundation for further study on drug resistance and virulence of Delftia strains.

Delftia deserti sp. nov., isolated from a desert soil sample.

A Gram-staining negative, short rod, motile, light brownish-pigmented bacterial strain, designated YIM Y792(T), was isolated from a soil sample taken from Turpan desert in Xinjiang Uyghur Autonomous Region, north-western China. Phylogenetic analysis indicated that strain YIM Y792(T) belongs to the genus Delftia. Strain YIM Y792(T) shared highest 16S rRNA gene sequence similarities with Delftia lacustris DSM 21246(T) (93.96 %), Delftia tsuruhatensis NBRC 16741(T) (93.74 %), and Delftia acidovorans NBRC 14950(T) (93.62 %). Growth of the strain YIM Y792(T) was found to occur at 20-45 °C (optimum at 30 °C), pH 6.0-9.0 (optimum at pH 7.0), and salinities of 0-3.0 % NaCl (optimum at 1.0 %). The new bacterium exhibits typical chemotaxonomic features of the genus Delftia with ubiqinone-8 (Q-8) as the predominant quinone and C16:0, Summed feature 3, Summed Feature 8 as major fatty acids (>10 %). The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, glycolipid, two unidentified phospholipids and one unidentified lipid. The G+C content of the genomic DNA of strain YIM Y792(T) was found to be 70.3 mol%. The DNA-DNA relatedness values between strain YIM Y792(T) and D. lacustris DSM 21246(T), D. tsuruhatensis NBRC16741(T), D. acidovorans NBRC14950(T) were 35.5 ± 2.0, 17.1 ± 1.8, 26.2 ± 2.0 %. Based on the phylogenetic, chemotaxonomic and phenotypic data presented here, we propose a novel species with the name Delftia desertisoli sp. nov. The type strain is YIM Y792(T) (=KCTC 42377(T) = JCM 30639(T)).

IncP-1ß plasmids of Comamonas sp. and Delftia sp. strains isolated from a wastewater treatment plant mediate resistance to and decolorization of the triphenylmethane dye crystal violet.

The application of toxic triphenylmethane dyes such as crystal violet (CV) in various industrial processes leads to large amounts of dye-contaminated sludges that need to be detoxified. Specific bacteria residing in wastewater treatment plants (WWTPs) are able to degrade triphenylmethane dyes. The objective of this work was to gain insights into the genetic background of bacterial strains capable of CV degradation. Three bacterial strains isolated from a municipal WWTP harboured IncP-1ß plasmids mediating resistance to and decolorization of CV. These isolates were assigned to the genera Comamonas and Delftia. The CV-resistance plasmid pKV29 from Delftia sp. KV29 was completely sequenced. In addition, nucleotide sequences of the accessory regions involved in conferring CV resistance were determined for plasmids pKV11 and pKV36 from the other two isolates. Plasmid pKV29 contains typical IncP-1ß backbone modules that are highly similar to those of previously sequenced IncP-1ß plasmids that confer antibiotic resistance, degradative capabilities or mercury resistance. The accessory regions located between the conjugative transfer (tra) and mating pair formation modules (trb) of all three plasmids analysed share common modules and include a triphenylmethane reductase gene, tmr, that is responsible for decolorization of CV. Moreover, these accessory regions encode other enzymes that are dispensable for CV degradation and hence are involved in so-far-unknown metabolic pathways. Analysis of plasmid-mediated degradation of CV in Escherichia coli by ultra-high-performance liquid chromatography-electrospray ionization-quadrupole-time-of-flight MS revealed that leuco crystal violet was the first degradation product. Michler's ketone and 4-dimethylaminobenzaldehyde appeared as secondary degradation metabolites. Enzymes encoded in the E. coli chromosome seem to be responsible for cleavage of leuco crystal violet. Plasmid-mediated degradation of triphenylmethane dyes such as CV is an option for the biotechnological treatment of sludges contaminated with these dyes.

The versatility of Delftia sp. isolates as tools for bioremediation and biofertilization technologies.

Two Pb(II)-resistant bacteria isolated from a soil containing 2,500 mg/kg of Pb were identified by 16S rRNA sequencing analysis as Delftia sp. and designated as 3C and 6C. Both isolates grew at a Pb(II) concentration of 62 mg/L and at the stationary phase showed a Pb(II)-sorption capability of 10 ± 1.5 (3C) and 5 ± 0.8 (6C) mg/g of biomass. Biochemical properties related to heavy metal resistance and plant growth promotion were analyzed and compared with the Cr(VI)-resistant plant growth-promoting Delftia sp. JD2, previously reported by our group. Both isolates and JD2 were resistant to Cr(VI), Pb(II) and many antibiotics, produced siderophores and the phytohormone indole-3-acetic, and showed clover growth-promoting activity in greenhouse conditions. Interestingly, the occurrence of integron class 1 was shown in all isolates. Our results add to previous reports and suggest that bacteria of the genus Delftia could be consider as good candidates for the design of technologies for cleaning up contaminated environments and/or the production of biofertilizers.

Delftia litopenaei sp. nov., a poly-ß-hydroxybutyrate-accumulating bacterium isolated from a freshwater shrimp culture pond.

A Gram-negative, short-rod-shaped, motile, non-spore-forming and poly-ß-hydroxybutyrate-accumulating bacterial strain, designated wsw-7(T), was isolated from a freshwater shrimp culture pond in Taiwan and was characterized using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that the closest relatives of strain wsw-7(T) were Delftia lacustris 332(T), Delftia tsuruhatensis T7(T) and Delftia acidovorans ATCC 15668(T), with sequence similarities of 98.5, 98.4 and 97.9%, respectively. Phylogenetic trees obtained with 16S rRNA gene sequences or the polyhydroxyalkanoate synthase (phaC) gene sequences revealed that strain wsw-7(T) and these three closest relatives formed an independent phylogenetic clade within the order Burkholderiales. Strain wsw-7(T) contained summed feature 3 (comprising C(16:1)ω7c and/or C(16:1)ω6c), C(18:0) and C(18:1)ω7c as predominant fatty acids. The major isoprenoid quinone was Q-8 and the DNA G+C content was 67.6 mol%. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminolipid and several uncharacterized phospholipids. On the basis of the genotypic, chemotaxonomic and phenotypic data, strain wsw-7(T) represents a novel species in the genus Delftia, for which the name Delftia litopenaei sp. nov. is proposed; the type strain is wsw-7(T) ( = BCRC 80212(T) = LMG 25724(T)).

Beta-1,3-glucanase from Delftia tsuruhatensis strain MV01 and its potential application in vinification.

During vinification microbial activities can spoil wine quality. As the wine-related lactic acid bacterium Pediococcus parvulus is able to produce slimes consisting of a ß-1,3-glucan, must and wine filtration can be difficult or impossible. In addition, the metabolic activities of several wild-type yeasts can also negatively affect wine quality. Therefore, there is a need for measures to degrade the exopolysaccharide from Pediococcus parvulus and to inhibit the growth of certain yeasts. We examined an extracellular ß-1,3-glucanase from Delftia tsuruhatensis strain MV01 with regard to its ability to hydrolyze both polymers, the ß-1,3-glucan from Pediococcus and that from yeast cell walls. The 29-kDa glycolytic enzyme was purified to homogeneity. It exhibited an optimal activity at 50°C and pH 4.0. The sequencing of the N terminus revealed significant similarities to ß-1,3-glucanases from different bacteria. In addition, the investigations indicated that this hydrolytic enzyme is still active under wine-relevant parameters such as elevated ethanol, sulfite, and phenol concentrations as well as at low pH values. Therefore, the characterized enzyme seems to be a useful tool to prevent slime production and undesirable yeast growth during vinification.

Metabolic characterization of a strain (BM90) of Delftia tsuruhatensis showing highly diversified capacity to degrade low molecular weight phenols.

A novel bacterium, strain BM90, previously isolated from Tyrrhenian Sea, was metabolically characterized testing its ability to use 95 different carbon sources by the Biolog system. The bacterium showed a broad capacity to use fatty-, organic- and amino-acids; on the contrary, its ability to use carbohydrates was extremely scarce. Strain BM90 was identified and affiliated to Delftia tsuruhatensis by molecular techniques based on 16S rRNA gene sequencing. D. tsuruhatensis BM90, cultivated in shaken cultures, was able to grow on various phenolic compounds and to remove them from its cultural broth. The phenols used, chosen for their presence in industrial or agro-industrial effluents, were grouped on the base of their chemical characteristics. These included benzoic acid derivatives, cinnamic acid derivatives, phenolic aldehyde derivatives, acetic acid derivatives and other phenolic compounds such as catechol and p-hydroxyphenylpropionic acid. When all the compounds (24) were gathered in the same medium (total concentration: 500 mg/l), BM90 caused the complete depletion of 18 phenols and the partial removal of two others. Only four phenolic compounds were not removed. Flow cytometry studies were carried out to understand the physiological state of BM90 cells in presence of the above phenols in various conditions. At the concentrations tested, a certain toxic effect was exerted only by the four compounds that were not metabolized by the bacterium.

Delftia lacustris sp. nov., a peptidoglycan-degrading bacterium from fresh water, and emended description of Delftia tsuruhatensis as a peptidoglycan-degrading bacterium.

Extracellular peptidoglycan is commonly found in natural environments, yet little is known about its biodegradation in nature. We here describe a novel peptidoglycan-degrading bacterium, designated strain 332T, isolated from mesotrophic lake water in Denmark. The strain was a Gram-negative-staining, motile rod. It had chitinase and lysozyme activities, which are relevant to peptidoglycan degradation, and was capable of utilizing several mono- and disaccharides, amino acids and organic acids. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that strain 332T belonged to the genus Delftia. Fatty acids of the strain included C8:0 and C10:0, which are characteristic of the genus Delftia. The DNA G+C content of the strain was 65.3 mol%. A DNA-DNA hybridization value of 66.2% was found between strain 332T and Delftia tsuruhatensis DSM 17581T. Based on differences in physiological and biochemical characteristics, the strain is considered to represent a novel species, for which the name Delftia lacustris sp. nov. is proposed. The type strain is 332T (=DSM 21246T=LMG 24775T). An emended description of Delftia tsuruhatensis is also presented.

[Isolation, identification and characteristics of a phoxim-degrading bacterium XSP-1].

A bacteria strain XSP-1 capable of utilizing phoxim as sole carbon source was isolated from sludge collected from a pesticide manufacturer. It was preliminarily identified as Delftia sp. according to its physiological-biochemical analysis and the similarity analysis of its 16S rRNA gene sequence (GenBank Accession No. EF061135). Strain XSP-1 could degrade 100 mg/L phoxim within 7 h completely. The optimal pH and temperature for degradation were 7.0 and 35 degrees C respectively. The degrading rate showed a positive correlation to the initial inoculum size. Strain XSP-1 also showed good degrading performance against methyl parathion, chlorpyrifos and fenitrothion. PCR detection with degenerated primers designed according to the conserved sequences of reported mpd gene did not find target band, but it needs further study to verify whether strain XSP-1 harbors a new mpd gene.

Degradation of plasticizer di-n-butylphthalate by Delftia sp. TBKNP-05.

Bacterial strain Delftia sp. TBKNP-05, isolated by para-hydroxybenzoate enrichment technique, is capable of degrading di-n-butylphthalate (DBP) as a sole source of carbon and energy. Analysis of intermediates by thin-layer chromatography and high-performance liquid chromatography indicated the presence of monobutylphthalate (MBP), phthalate (PA), and protocatechuate (PCA). The washed cells grown on DBP and PA showed appreciable oxidation of DBP, MBP, PA, and PCA. The enzyme activities in cell-free extracts of Delftia sp. TBKNP-05 exhibited the presence of DBP esterase, MBP esterase, PA-dioxygenase, and PCA 4,5-dioxygenase. The PCA is metabolized by meta-cleavage pathway, leading to further mineralization of the compound in this bacterium.

Degradation of a Plasticizer, di-n-Butylphthalate by Delftia sp. TBKNP-05.

A bacterial strain Delftia sp. TBKNP-05 isolated by para-hydroxybenzoate enrichment technique is capable of degrading di-n-butylphthalate (DBP) as a sole source of carbon and energy. Analysis of intermediates by thin layer chromatography and high performance liquid chromatography indicated the presence of monobutylphthalate (MBP), phthalate (PA), and protocatechuate (PCA). The washed cells grown on DBP and PA showed appreciable oxidation of DBP, MBP, PA, and PCA. The enzyme activities in cell free extracts of Delftia sp. TBKNP-05 exhibited the presence of DBP esterase, MBP esterase, PA-dioxygenase, and protocatechuate 4, 5-dioxygenase. The protocatechuate is metabolized by a meta-cleavage pathway leading to further mineralization of the compound in this bacterium.