The micelle-templated silica （MTS） was firstly chemically modified with 3-glycidoxypropyl-trimethoxysilane （GPTMS） before immobilized with pyoverdin I. The characteristics of pyoverdin I-anchored onto the modified...The micelle-templated silica （MTS） was firstly chemically modified with 3-glycidoxypropyl-trimethoxysilane （GPTMS） before immobilized with pyoverdin I. The characteristics of pyoverdin I-anchored onto the modified MTS were investigated using fluorescence, infrared spectra and scanning electron microscopy. The specific surface area of all materials was calculated by Branauer, Emmett and Teller （BET） method using nitrogen isotherm adsorption data. As the results, the surface area of commercial silica gel decreased from 609.2 to 405.4 m2/g, it indicated that the pyoverdin I could be immobilized onto the surface of silica solid support. This adsorbent was used for extraction of Fe（Ⅲ）, Cu（Ⅱ）, Zn（Ⅱ）, and Pb（Ⅱ） in artificial metals contaminated water. Experimental conditions for effective adsorption of trace levels of metal ions were optimized with respect to different experimental parameters using batch procedure. The optimum pH value for the removal of metal ions simultaneously on this adsorbent was 4.0. Complete desorption of the adsorbed metal ions from the adsorbent was carried out using 0.25 mol/L of EDTA. The effect of different cations and anions on the adsorption of these metals on adsorbent was studied and the results showed that the proposed adsorbent could be applied to the highly saline samples and the sample which contains some transition metals.展开更多
This study focuses on the isolation and characterization of a novel strain of siderophore producing bacterium, i.e., Pseudomonas aeruginosa BUP2 (Pa BUP2) from the rumen of Malabari goat, coupled with qualitative and ...This study focuses on the isolation and characterization of a novel strain of siderophore producing bacterium, i.e., Pseudomonas aeruginosa BUP2 (Pa BUP2) from the rumen of Malabari goat, coupled with qualitative and quantitative analyses of the siderophore produced by it. Pa BUP2—a facultative anaerobe was tuned to be an aerobe by repeatedly growing in Benjamin flask. The new isolate was grown in a specially designed semi-synthetic medium, designated as BUP medium, and the yellowish-green pigment produced was identified as a typical siderophore by spectrophotometry, Chromazurol-S assay, thin layer chromatography and isolectric focusing (IEF). The characteristic orange fluorescence upon UV irradiation on chromatogram and absorption maximum at λ404 confirmed that the characteristic siderophore produced by Pa BUP2 was a typical pyoverdine (PVD). This PVD was further categorized under type 2 by comparing its profile on the IEF gel with that of the representative strains of each PVD types, viz., Pa O1, Pa ATCC 27853 and Pa6. Moreover, the type 2 PVD was purified by XAD-4 Amberlite column chromatography and quantified;maximum yield (11.17 mg/ml) was observed on day 4 of incubation (37°C). Thus, it was confirmed that the bacterium isolated from the rumen content of Malabari goat is a novel strain of Pa capable of producing large quantity of PVD type 2 in specially designed BUP medium under aerobic condition, and that its clinical and industrial implications remain elusive.展开更多
The majority of the root microbiota formation derives from soil-dwelling microorganisms.The limited extent of thorough investigation leads to a dearth of knowledge concerning the intricate mechanisms of microbe-microb...The majority of the root microbiota formation derives from soil-dwelling microorganisms.The limited extent of thorough investigation leads to a dearth of knowledge concerning the intricate mechanisms of microbe-microbe interaction implicated in the establishment of root microbiota.Therefore,the taxonomic signatures in bacterial inhibition profiles were determined by in vitro testing of 39,204 binary interbacterial interactions.However,findings from genetic and metabolomic studies elucidated that co-functioning of the antimicrobial 2,4-d iacetylphloroglucinol(DAPG)and the iron chelator pyoverdine as exometabolites has significantly contributed to the potent inhibitory activities of the highly antagonistic Pseudomonas brassicacearum R401.Microbiota restoration with a core of Arabidopsis thaliana root commensals showed that these exometabolites possess a root niche-specific function in establishing root competence and inducing anticipated changes in root surroundings.Both biosynthetic operons are abundant in roots in natural habitats,indicating that these exometabolites co-functioning is an adaptive feature that helps Pseudomonad dominate the root microbiota.展开更多
Pyoverdine is one of the siderphores excreted by Pseudomonas aeruginosa that can help microbe to uptake iron in vitro. To determine the effect of pyoverdine chelating with iron, we purified the free pyoverdine and app...Pyoverdine is one of the siderphores excreted by Pseudomonas aeruginosa that can help microbe to uptake iron in vitro. To determine the effect of pyoverdine chelating with iron, we purified the free pyoverdine and applied the dynamic laser light scattering （DLS） to detect the interaction between the pyoverdine and ferric hydroxide. The real-time DLS data analysis indicated that pyoverdine can directly combine with Fe（OH）3 to form complexes and these substances are gradually degraded by themselves then completely disappeared. In our experiment, we have demonstrated that pyoverdine may not only chelate ferric ion but also availably dissolve ferric hydroxide which assists bacteria to survive in iron-deficient environments.展开更多
基金supported by the Center of Excellence for Innovation in Chemistry (PERCH-CIC), Commission on Higher Education, Ministry of EducationKhon Kaen University and the National Research Council of Thailand (NRCT) for facilitates both instruments and chemical including research grants
文摘The micelle-templated silica （MTS） was firstly chemically modified with 3-glycidoxypropyl-trimethoxysilane （GPTMS） before immobilized with pyoverdin I. The characteristics of pyoverdin I-anchored onto the modified MTS were investigated using fluorescence, infrared spectra and scanning electron microscopy. The specific surface area of all materials was calculated by Branauer, Emmett and Teller （BET） method using nitrogen isotherm adsorption data. As the results, the surface area of commercial silica gel decreased from 609.2 to 405.4 m2/g, it indicated that the pyoverdin I could be immobilized onto the surface of silica solid support. This adsorbent was used for extraction of Fe（Ⅲ）, Cu（Ⅱ）, Zn（Ⅱ）, and Pb（Ⅱ） in artificial metals contaminated water. Experimental conditions for effective adsorption of trace levels of metal ions were optimized with respect to different experimental parameters using batch procedure. The optimum pH value for the removal of metal ions simultaneously on this adsorbent was 4.0. Complete desorption of the adsorbed metal ions from the adsorbent was carried out using 0.25 mol/L of EDTA. The effect of different cations and anions on the adsorption of these metals on adsorbent was studied and the results showed that the proposed adsorbent could be applied to the highly saline samples and the sample which contains some transition metals.
文摘This study focuses on the isolation and characterization of a novel strain of siderophore producing bacterium, i.e., Pseudomonas aeruginosa BUP2 (Pa BUP2) from the rumen of Malabari goat, coupled with qualitative and quantitative analyses of the siderophore produced by it. Pa BUP2—a facultative anaerobe was tuned to be an aerobe by repeatedly growing in Benjamin flask. The new isolate was grown in a specially designed semi-synthetic medium, designated as BUP medium, and the yellowish-green pigment produced was identified as a typical siderophore by spectrophotometry, Chromazurol-S assay, thin layer chromatography and isolectric focusing (IEF). The characteristic orange fluorescence upon UV irradiation on chromatogram and absorption maximum at λ404 confirmed that the characteristic siderophore produced by Pa BUP2 was a typical pyoverdine (PVD). This PVD was further categorized under type 2 by comparing its profile on the IEF gel with that of the representative strains of each PVD types, viz., Pa O1, Pa ATCC 27853 and Pa6. Moreover, the type 2 PVD was purified by XAD-4 Amberlite column chromatography and quantified;maximum yield (11.17 mg/ml) was observed on day 4 of incubation (37°C). Thus, it was confirmed that the bacterium isolated from the rumen content of Malabari goat is a novel strain of Pa capable of producing large quantity of PVD type 2 in specially designed BUP medium under aerobic condition, and that its clinical and industrial implications remain elusive.
基金National Natural Science Foundation of China(31725003 to X.S.).
文摘The majority of the root microbiota formation derives from soil-dwelling microorganisms.The limited extent of thorough investigation leads to a dearth of knowledge concerning the intricate mechanisms of microbe-microbe interaction implicated in the establishment of root microbiota.Therefore,the taxonomic signatures in bacterial inhibition profiles were determined by in vitro testing of 39,204 binary interbacterial interactions.However,findings from genetic and metabolomic studies elucidated that co-functioning of the antimicrobial 2,4-d iacetylphloroglucinol(DAPG)and the iron chelator pyoverdine as exometabolites has significantly contributed to the potent inhibitory activities of the highly antagonistic Pseudomonas brassicacearum R401.Microbiota restoration with a core of Arabidopsis thaliana root commensals showed that these exometabolites possess a root niche-specific function in establishing root competence and inducing anticipated changes in root surroundings.Both biosynthetic operons are abundant in roots in natural habitats,indicating that these exometabolites co-functioning is an adaptive feature that helps Pseudomonad dominate the root microbiota.
基金We thank professor Fan Jin of University of Science and Technology of China provided idea and designed the experiments. This work was supported by the National Program on Key Basic Research Project （No.2012CB933802） and the National Natural Science Foundation of China （No.21274141, No.21104071）.
文摘Pyoverdine is one of the siderphores excreted by Pseudomonas aeruginosa that can help microbe to uptake iron in vitro. To determine the effect of pyoverdine chelating with iron, we purified the free pyoverdine and applied the dynamic laser light scattering （DLS） to detect the interaction between the pyoverdine and ferric hydroxide. The real-time DLS data analysis indicated that pyoverdine can directly combine with Fe（OH）3 to form complexes and these substances are gradually degraded by themselves then completely disappeared. In our experiment, we have demonstrated that pyoverdine may not only chelate ferric ion but also availably dissolve ferric hydroxide which assists bacteria to survive in iron-deficient environments.
