A wide variety of different types of microorganisms are known to produce intracellular energy and carbon storage products, which have been generally described as being poly (β-hydroxybutyrate), PHB, but which are, mo...A wide variety of different types of microorganisms are known to produce intracellular energy and carbon storage products, which have been generally described as being poly (β-hydroxybutyrate), PHB, but which are, more often than not, copolymers containing different alkyl groups at the β-position. Hence, PHB belongs to the family ofpoly (β-hydroxyalkanoastes), PHA, all of which are usually formed as intracellular inclusions in bacteria under unbalanced growth conditions. Recently, it became of industrial interest to evaluate these PHA polyesters as natural biodegradable and biocompatible plastics for a wide range of possible applications, such as surgical sutures or packaging containers. For industrial applications, the controlled incorporation of repeating units with different chain lengths into a series of copolymers is desirable in order to produce polyesters with a range of material properties because physical and chemical characteristics depend strongly on the polymer composition. Such 'tailor-made' copolymers can be produced under controlled growth conditions in that, if a defined mixture of substrates for a certain type of microorganisms is supplied, a well defined and reproducible copolymer is formed.展开更多
Reviewing the current state of knowledge about sequential extraction applied for soil vanadium （V） fractionation, we identified an urgent requirement of an sequential extraction （SE） specified for V. Namely, almos...Reviewing the current state of knowledge about sequential extraction applied for soil vanadium （V） fractionation, we identified an urgent requirement of an sequential extraction （SE） specified for V. Namely, almost all previous SE extracted only 8.4%-48% of total V in soils （excluding residue）. Thus, we proposed an eight-step SE for V fractionation in soils according to the knowledge gained from literature and our own dissolution experiments with model minerals. After extracting the mobilisable and adsorbed V with de-ionised water and 5 mmol/L phosphate, I moVL pyrophosphate was applied to gather organic matter bound V which minimised the artefact dissolving AI and Fe （hydr）oxides occurred when using HNO3-H202 for extraction. Extraction with 0.4 mol/L NH2OH. HCI was highly selective toward manganese oxides. Fractionation of different crystalline A1 and Fe （hydr）oxides associated V with 1 mol/L HCI, 0.2 mol/L oxalate buffer and 4 mol/L HCI at 95℃especially improved the extractability of V incorporated with crystalline phase associated V. The suitability of our new SE scheme was confirmed by its higher selectivity against the target phases and higher extraction efficiencies （55%-77% of total V） with model minerals and 6 soils of different properties than previous SE.展开更多
In nature, microbes are involved in weathering of rocks, in mobilization of metals from minerals, and in metal precipitation and deposition. These microbiological principles and processes can be adapted to treat parti...In nature, microbes are involved in weathering of rocks, in mobilization of metals from minerals, and in metal precipitation and deposition. These microbiological principles and processes can be adapted to treat particulate solid wastes. Especially the microbiological solubilization of metals from solid minerals （termed bioleaching） to obtain metal values is a well-known technique in the mining industry. We focus here on non-mining minerai wastes to demonstrate the applicability of mining-based technologies for the treatment of metal-containing solid wastes. In the case study presented, microbial metal mobilization from particulate fly ash （originating from municipal solid waste incineration） by Acidithiobacilli resulted in cadmium, copper, and zinc mobilization of 〉80%, whereas lead, chromium, and nickel were mobilized by 2, 11 and 32%, respectively. In addition, the potential of HCN-forming bacteria （Chromobacterium violaceum, Pseudornonas fluorescens） was investigated to mobilize metals when grown in the presence of solid materials （e.g.,copper-containing ores, electronic scrap, spent automobile catalytic converters）. C. violaceum was found capable of mobilizina nickel as tetracyanonickelate from fine-grained nickel powder. Gold was microbially solubJlized as dicyanoaurate from electronic waste. Additionally, cyanide-complexed copper was detected during biological treatment of shredded printed circuit-board scraps. Water-soluble copper and platinum cyanide were also detected during the treatment of spent automobile catalytic converters.展开更多
Aims the goal of the study was to apply Fourier transform infrared(FtIr)spectroscopy followed by chemometrical data treatment for the dif-ferentiation of fungi-infected perennial ryegrass(Lolium perenne)from uninfecte...Aims the goal of the study was to apply Fourier transform infrared(FtIr)spectroscopy followed by chemometrical data treatment for the dif-ferentiation of fungi-infected perennial ryegrass(Lolium perenne)from uninfected grass.Methods FtIr was used to rapidly discriminate between leaves of peren-nial ryegrass(L.perenne)infected by a fungal endophyte(Epichloë;asexual forms:Neotyphodium)and uninfected leaves.besides drying and grinding of the sampled leaves,no other preparation steps were needed.FtIr measurements were performed in the attenuated total reflection(at)mode.aliquots of powdered leaf samples were placed on a Znse crystal and the spectra were collected,followed by chemometrical analysis(multidimensional factor analysis,hier-archical cluster analysis).Important Findingsat-FtIr allowed a rapid detection of fungal infections in the plant material and proved to be a fast and reliable tool for the differentiation of plant biomass without the need of time-consuming sample preparation.展开更多
A photoanode structure for dye-sensitized solar cells has been applied into the photocatalytic/electrochemical cooperative degradation of methylene blue solutions.The low eutectic point of titanium dioxide(TiO2)with a...A photoanode structure for dye-sensitized solar cells has been applied into the photocatalytic/electrochemical cooperative degradation of methylene blue solutions.The low eutectic point of titanium dioxide(TiO2)with a fluorine-doped tin dioxide(FTO)conductive layer results in a high reactivity of TiO2for the photocatalytic process as well as a good electron transfer for the electrochemical process.The porous TiO2layer maintains a large surface area for the degradations.Through the combinational process,the degradation velocity was improved by*36%,compared to a pure photocatalytic process.展开更多
Aims In grassland biodiversity experiments,positive biodiversity effects on primary productivity increase over time.recent research has shown that differential selection in monoculture and mixed-species communities le...Aims In grassland biodiversity experiments,positive biodiversity effects on primary productivity increase over time.recent research has shown that differential selection in monoculture and mixed-species communities leads to the rapid emergence of monoculture and mix-ture types,adapted to their own biotic community.We used eight plant species selected for 8 years in such a biodiversity experiment to test if monoculture and mixture types differed in metabolic pro-files using infrared spectroscopy.Methods Fourier transform infrared spectroscopy(FTIr)was used to assess metabolic fingerprints of leaf samples of 10 individuals of each species from either monocultures or mixtures.The FTIr spectra were analyzed using multivariate procedures to assess(i)whether indi-viduals within species could be correctly assigned to monoculture or mixture history based on the spectra alone and(ii)which parts of the spectra drive the group assignment,i.e.which metabolic groups were subject to differential selection in monocultures vs.mixtures.Important Findings Plant individuals within each of the eight species could be classified as either from monoculture or mixture selection history based on their FTIr spectra.Different metabolic groups were differentially selected in the different species;some of them may be related to defense of patho-gens accumulating more strongly in monocultures than in mixtures.The rapid selection of the monoculture and mixture types within the eight study species could have been due to a sorting-out process based on large initial genetic or epigenetic variation within the species.展开更多
文摘A wide variety of different types of microorganisms are known to produce intracellular energy and carbon storage products, which have been generally described as being poly (β-hydroxybutyrate), PHB, but which are, more often than not, copolymers containing different alkyl groups at the β-position. Hence, PHB belongs to the family ofpoly (β-hydroxyalkanoastes), PHA, all of which are usually formed as intracellular inclusions in bacteria under unbalanced growth conditions. Recently, it became of industrial interest to evaluate these PHA polyesters as natural biodegradable and biocompatible plastics for a wide range of possible applications, such as surgical sutures or packaging containers. For industrial applications, the controlled incorporation of repeating units with different chain lengths into a series of copolymers is desirable in order to produce polyesters with a range of material properties because physical and chemical characteristics depend strongly on the polymer composition. Such 'tailor-made' copolymers can be produced under controlled growth conditions in that, if a defined mixture of substrates for a certain type of microorganisms is supplied, a well defined and reproducible copolymer is formed.
基金Gunter Ilgen(University of Bayreuth,Germany)for the support with analysissupported by the China Scholarship Council(No.2011624130)the Swiss National Science Foundation(No.PZ00P2 142232)
文摘Reviewing the current state of knowledge about sequential extraction applied for soil vanadium （V） fractionation, we identified an urgent requirement of an sequential extraction （SE） specified for V. Namely, almost all previous SE extracted only 8.4%-48% of total V in soils （excluding residue）. Thus, we proposed an eight-step SE for V fractionation in soils according to the knowledge gained from literature and our own dissolution experiments with model minerals. After extracting the mobilisable and adsorbed V with de-ionised water and 5 mmol/L phosphate, I moVL pyrophosphate was applied to gather organic matter bound V which minimised the artefact dissolving AI and Fe （hydr）oxides occurred when using HNO3-H202 for extraction. Extraction with 0.4 mol/L NH2OH. HCI was highly selective toward manganese oxides. Fractionation of different crystalline A1 and Fe （hydr）oxides associated V with 1 mol/L HCI, 0.2 mol/L oxalate buffer and 4 mol/L HCI at 95℃especially improved the extractability of V incorporated with crystalline phase associated V. The suitability of our new SE scheme was confirmed by its higher selectivity against the target phases and higher extraction efficiencies （55%-77% of total V） with model minerals and 6 soils of different properties than previous SE.
文摘In nature, microbes are involved in weathering of rocks, in mobilization of metals from minerals, and in metal precipitation and deposition. These microbiological principles and processes can be adapted to treat particulate solid wastes. Especially the microbiological solubilization of metals from solid minerals （termed bioleaching） to obtain metal values is a well-known technique in the mining industry. We focus here on non-mining minerai wastes to demonstrate the applicability of mining-based technologies for the treatment of metal-containing solid wastes. In the case study presented, microbial metal mobilization from particulate fly ash （originating from municipal solid waste incineration） by Acidithiobacilli resulted in cadmium, copper, and zinc mobilization of 〉80%, whereas lead, chromium, and nickel were mobilized by 2, 11 and 32%, respectively. In addition, the potential of HCN-forming bacteria （Chromobacterium violaceum, Pseudornonas fluorescens） was investigated to mobilize metals when grown in the presence of solid materials （e.g.,copper-containing ores, electronic scrap, spent automobile catalytic converters）. C. violaceum was found capable of mobilizina nickel as tetracyanonickelate from fine-grained nickel powder. Gold was microbially solubJlized as dicyanoaurate from electronic waste. Additionally, cyanide-complexed copper was detected during biological treatment of shredded printed circuit-board scraps. Water-soluble copper and platinum cyanide were also detected during the treatment of spent automobile catalytic converters.
文摘Aims the goal of the study was to apply Fourier transform infrared(FtIr)spectroscopy followed by chemometrical data treatment for the dif-ferentiation of fungi-infected perennial ryegrass(Lolium perenne)from uninfected grass.Methods FtIr was used to rapidly discriminate between leaves of peren-nial ryegrass(L.perenne)infected by a fungal endophyte(Epichloë;asexual forms:Neotyphodium)and uninfected leaves.besides drying and grinding of the sampled leaves,no other preparation steps were needed.FtIr measurements were performed in the attenuated total reflection(at)mode.aliquots of powdered leaf samples were placed on a Znse crystal and the spectra were collected,followed by chemometrical analysis(multidimensional factor analysis,hier-archical cluster analysis).Important Findingsat-FtIr allowed a rapid detection of fungal infections in the plant material and proved to be a fast and reliable tool for the differentiation of plant biomass without the need of time-consuming sample preparation.
基金supported by the National High Technology Research and Development Program of China (2011AA050507)the National Natural Science Foundation of China (61006150,50821004,and 61076051)
文摘A photoanode structure for dye-sensitized solar cells has been applied into the photocatalytic/electrochemical cooperative degradation of methylene blue solutions.The low eutectic point of titanium dioxide(TiO2)with a fluorine-doped tin dioxide(FTO)conductive layer results in a high reactivity of TiO2for the photocatalytic process as well as a good electron transfer for the electrochemical process.The porous TiO2layer maintains a large surface area for the degradations.Through the combinational process,the degradation velocity was improved by*36%,compared to a pure photocatalytic process.
基金Swiss National Science Foundation(130720 to B.S.).
文摘Aims In grassland biodiversity experiments,positive biodiversity effects on primary productivity increase over time.recent research has shown that differential selection in monoculture and mixed-species communities leads to the rapid emergence of monoculture and mix-ture types,adapted to their own biotic community.We used eight plant species selected for 8 years in such a biodiversity experiment to test if monoculture and mixture types differed in metabolic pro-files using infrared spectroscopy.Methods Fourier transform infrared spectroscopy(FTIr)was used to assess metabolic fingerprints of leaf samples of 10 individuals of each species from either monocultures or mixtures.The FTIr spectra were analyzed using multivariate procedures to assess(i)whether indi-viduals within species could be correctly assigned to monoculture or mixture history based on the spectra alone and(ii)which parts of the spectra drive the group assignment,i.e.which metabolic groups were subject to differential selection in monocultures vs.mixtures.Important Findings Plant individuals within each of the eight species could be classified as either from monoculture or mixture selection history based on their FTIr spectra.Different metabolic groups were differentially selected in the different species;some of them may be related to defense of patho-gens accumulating more strongly in monocultures than in mixtures.The rapid selection of the monoculture and mixture types within the eight study species could have been due to a sorting-out process based on large initial genetic or epigenetic variation within the species.
