A bacterial strain (AD26) capable of utilizing atrazine as a sole nitrogen source for growth was isolated from an industrial wastewater sample by enrichment culture. The 16S rRNA gene sequencing identified AD26 as an ...A bacterial strain (AD26) capable of utilizing atrazine as a sole nitrogen source for growth was isolated from an industrial wastewater sample by enrichment culture. The 16S rRNA gene sequencing identified AD26 as an Arthrobacter sp. PCR assays indicated that AD26 contained atrazine-degrading genes trzN and atzBC. The trzN gene of AD26 only differs from the trzN of Arthrobacter aurescens TC1 by one base (A→T at 907) and one amino acid (Met→Leu at 303). The specific activity of trzN of AD26 in crude cell ext...展开更多
Isolation of new bacterial strains and recognition of their metabolic activities are highly desirable for sustainability of natural ecosystems. Biodegradation of dimethyl phthalate （DMP） under anoxic conditions has ...Isolation of new bacterial strains and recognition of their metabolic activities are highly desirable for sustainability of natural ecosystems. Biodegradation of dimethyl phthalate （DMP） under anoxic conditions has been shown to occur as a series of sequential steps using strain CW-1 isolated from digested sludge of Sibao Wastewater Treatment Plant in Hangzhou, China. The microbial colony on LB medium was yellowish, 3-5 mm in diameter, convex in the center, and embedded in mucous externally. The individual cells of strain CW-1 are irregular rods, measuring （0.6-0.7）×（0.9-1.0） pm, V-shaped, with clubbed ends, Gram positive and without any filaments. 16S rDNA （ 1438 bp） sequence analysis showed that the strain was related to Arthrobacter sp. CW-1 and can degrade PAEs utilizing nitrate as electron acceptor, but cannot mineralize DMP completely. The degradation pathway was recommended as： dimethyl phthalate （DMP）→monomethyl phthalate （MMP）--,phthalic acid （PA）. DMP biodegradation was a first order reaction with degradation rate constant of 0.3033 d 1 and half-life 2.25 d. The DMP conversion to PA by CW-1 could be described by using sequential kinetic model.展开更多
Arthrobacter sp. SUK 1205 isolated from metalliferous chromite mine environment of Orissa, India showed wide degree of tolerance to heavy metals including Cr(VI), variety of antibiotics and was also capable of reducin...Arthrobacter sp. SUK 1205 isolated from metalliferous chromite mine environment of Orissa, India showed wide degree of tolerance to heavy metals including Cr(VI), variety of antibiotics and was also capable of reducing Cr(VI) during growth. Freshly grown whole cells of this bacterium were evaluated for chromate reduction under batch culture using Vogel Bonner (V. B.) broth as the base. Cells of SUK 1205 were capable of completely reducing 100 μM Cr(VI) in V. B. broth within 48 h of incubation. Reduction of chromate increased with increase in cell density which attained maximum at 1010 cells/ml, however, reverse was the phenomenon when the concentration of Cr(VI) increased gradually. Glycerol, glycine and glucose promoted chromate reduction efficiency of the cells when used as electron donors. Optimum pH and temperature were found to be 7.0 and 35°C respectively. The process of reduction was inhibited by Ni(II), Mn(II), Zn(II) and Co(II), but Cu(II) and Fe(III) was promotive in nature. On the other hand, 2, 4-dinitrophenol was found to be neither promotive nor inhibitory for the reduction process, but carbonyl cyanide-m-chloro phenyl hydrazone, sodium azide, sodium fluoride and N,N,-dicyclohexyl carboiimide were inhibitory. Cells of SUK 1205 when permeabilized with toluene, triton X-100 and tween 80 showed an enhancement of the process and thereby indicated that reduction of Cr(VI) was mainly associated with soluble component of the cells. Arthrobacter sp. SUK 1205, therefore, showed great promise for use in Cr(VI) detoxification under a wide range of environmental conditions.展开更多
Investigating enzymatic reaction in multimeric enzymes is utmost interest to improve our understanding of the mechanism of enzymatic reaction and regulation. In this study,
In this study,an Arthrobacter strain from desert soils in the Shule River Valley was isolated,China,which has a strong ability to convert cellulose to potential biofuel.In total,from five soil sample sites,six strains...In this study,an Arthrobacter strain from desert soils in the Shule River Valley was isolated,China,which has a strong ability to convert cellulose to potential biofuel.In total,from five soil sample sites,six strains were isolated that grew well on CMC-Agar medium,with colony diameters ranging from 3~4 mm,among them,one strain had a strong ability to produce biofuels.Based on morphological and phylogenetic analyses,the isolate was identified as Arthrobacter nitroguajacolicus strain SLP1.The chemical properties of the biofuel extracted from the fermentation broth of strain SLP1 were analysed by gas chromatography and mass spectrometry.A total of 41 kinds of carbon compounds were identified,of those,five were detected at peak concentration and the carbon numbers ranged from C16–C22,which can be classified as alkanes,alkenes,and alcohols.Furthermore,biofuel-producing ability of strain SLP1 was enhanced using NTG mutagen.In a total of 94 mutant strains,four show the most enhanced biofuel production relative to the original strain.Biofuel production conditions were optimized by growing the four mutant strains on LB-Agar and SS-Agar medium.展开更多
Following the bioautographic te-chnique, 24 lysine producing microor-ganisms have been isolated from amongthe 263 hydrocarbon utilisers. Morphological, cultural and biochemicalcharacters of two promising isolates,have...Following the bioautographic te-chnique, 24 lysine producing microor-ganisms have been isolated from amongthe 263 hydrocarbon utilisers. Morphological, cultural and biochemicalcharacters of two promising isolates,have been studied. One of them iden-tified as Arthrobacter globiformis andthe other as Micrococcus varians, pro-duce 3.4 and 2.6 g lysine per litreof medium.展开更多
The genus Arthrobacter was established in 1947 by Conn & Dimmick. So far, more than 70 recognized?species of the genus Arthrobacter have been certified. Its special functions have been widely known by researchers,...The genus Arthrobacter was established in 1947 by Conn & Dimmick. So far, more than 70 recognized?species of the genus Arthrobacter have been certified. Its special functions have been widely known by researchers, such as, in agricultural, in medical, in industrial, and in environmental areas, etc. What deserves to be mentioned is that some species of genus Arthrobacter have showed the function of degrading pesticides, fixing nitrogen, producing beneficial enzyme, treating sewage, and so on. Recently, the applications of the genus Arthrobacter, especially the VBNC?(viable but non-culturable) bacteria of this genus in the field of contaminated environment repair attract people’s attention and some related research results have also been obtained. The functions that we have known are waiting for us to study about mechanism, deeply. And, we can look forward to discovering more potential functions and applications of this genus in ecological environment. In the meantime, these discoveries must bring more new changes and knowledge.展开更多
The removal of Cr(III) from aqueous Cr(III) using Arthrobacter nicotianae cells was examined. Cr(III) removal was strongly affected by the pH of the solution and the amounts of Cr(III) removed increased as the pH (1 -...The removal of Cr(III) from aqueous Cr(III) using Arthrobacter nicotianae cells was examined. Cr(III) removal was strongly affected by the pH of the solution and the amounts of Cr(III) removed increased as the pH (1 - 5) of the solution increased. The removal of Cr(III) using the cells was also strongly affected by the Cr(III) concentration of the solution, and obeyed the Langmuir isotherm. The percentage of Cr increased as the cell quantity increased, whereas the amount of Cr (μmol/g dry wt. cells) decreased. The removal of Cr(III) using the cells was very fast, and reached an equilibrium within 6 h from the supply of Cr(III) in the solution. A small amount of Cr(III) absorbed by immobilized cells was desorbed at 30oC;however, most was desorbed at reflux temperature using diluted HCl. Cr(III) adsorption-desorption cycles can be repeated 5 times using immobilized cells. These results have practical implications for industrial wastewater management.展开更多
文摘A bacterial strain (AD26) capable of utilizing atrazine as a sole nitrogen source for growth was isolated from an industrial wastewater sample by enrichment culture. The 16S rRNA gene sequencing identified AD26 as an Arthrobacter sp. PCR assays indicated that AD26 contained atrazine-degrading genes trzN and atzBC. The trzN gene of AD26 only differs from the trzN of Arthrobacter aurescens TC1 by one base (A→T at 907) and one amino acid (Met→Leu at 303). The specific activity of trzN of AD26 in crude cell ext...
文摘Isolation of new bacterial strains and recognition of their metabolic activities are highly desirable for sustainability of natural ecosystems. Biodegradation of dimethyl phthalate （DMP） under anoxic conditions has been shown to occur as a series of sequential steps using strain CW-1 isolated from digested sludge of Sibao Wastewater Treatment Plant in Hangzhou, China. The microbial colony on LB medium was yellowish, 3-5 mm in diameter, convex in the center, and embedded in mucous externally. The individual cells of strain CW-1 are irregular rods, measuring （0.6-0.7）×（0.9-1.0） pm, V-shaped, with clubbed ends, Gram positive and without any filaments. 16S rDNA （ 1438 bp） sequence analysis showed that the strain was related to Arthrobacter sp. CW-1 and can degrade PAEs utilizing nitrate as electron acceptor, but cannot mineralize DMP completely. The degradation pathway was recommended as： dimethyl phthalate （DMP）→monomethyl phthalate （MMP）--,phthalic acid （PA）. DMP biodegradation was a first order reaction with degradation rate constant of 0.3033 d 1 and half-life 2.25 d. The DMP conversion to PA by CW-1 could be described by using sequential kinetic model.
文摘Arthrobacter sp. SUK 1205 isolated from metalliferous chromite mine environment of Orissa, India showed wide degree of tolerance to heavy metals including Cr(VI), variety of antibiotics and was also capable of reducing Cr(VI) during growth. Freshly grown whole cells of this bacterium were evaluated for chromate reduction under batch culture using Vogel Bonner (V. B.) broth as the base. Cells of SUK 1205 were capable of completely reducing 100 μM Cr(VI) in V. B. broth within 48 h of incubation. Reduction of chromate increased with increase in cell density which attained maximum at 1010 cells/ml, however, reverse was the phenomenon when the concentration of Cr(VI) increased gradually. Glycerol, glycine and glucose promoted chromate reduction efficiency of the cells when used as electron donors. Optimum pH and temperature were found to be 7.0 and 35°C respectively. The process of reduction was inhibited by Ni(II), Mn(II), Zn(II) and Co(II), but Cu(II) and Fe(III) was promotive in nature. On the other hand, 2, 4-dinitrophenol was found to be neither promotive nor inhibitory for the reduction process, but carbonyl cyanide-m-chloro phenyl hydrazone, sodium azide, sodium fluoride and N,N,-dicyclohexyl carboiimide were inhibitory. Cells of SUK 1205 when permeabilized with toluene, triton X-100 and tween 80 showed an enhancement of the process and thereby indicated that reduction of Cr(VI) was mainly associated with soluble component of the cells. Arthrobacter sp. SUK 1205, therefore, showed great promise for use in Cr(VI) detoxification under a wide range of environmental conditions.
文摘Investigating enzymatic reaction in multimeric enzymes is utmost interest to improve our understanding of the mechanism of enzymatic reaction and regulation. In this study,
基金financially supported by the National Natural Science Foundation of China(31400437,31560121)the international cooperation program of Gansu(1504WKCA097)+1 种基金the application transformation foundation of CAS(HHS-CGZH-1602)UK BBSRC China Partnering Grant(BB/J020419/1)
文摘In this study,an Arthrobacter strain from desert soils in the Shule River Valley was isolated,China,which has a strong ability to convert cellulose to potential biofuel.In total,from five soil sample sites,six strains were isolated that grew well on CMC-Agar medium,with colony diameters ranging from 3~4 mm,among them,one strain had a strong ability to produce biofuels.Based on morphological and phylogenetic analyses,the isolate was identified as Arthrobacter nitroguajacolicus strain SLP1.The chemical properties of the biofuel extracted from the fermentation broth of strain SLP1 were analysed by gas chromatography and mass spectrometry.A total of 41 kinds of carbon compounds were identified,of those,five were detected at peak concentration and the carbon numbers ranged from C16–C22,which can be classified as alkanes,alkenes,and alcohols.Furthermore,biofuel-producing ability of strain SLP1 was enhanced using NTG mutagen.In a total of 94 mutant strains,four show the most enhanced biofuel production relative to the original strain.Biofuel production conditions were optimized by growing the four mutant strains on LB-Agar and SS-Agar medium.
文摘Following the bioautographic te-chnique, 24 lysine producing microor-ganisms have been isolated from amongthe 263 hydrocarbon utilisers. Morphological, cultural and biochemicalcharacters of two promising isolates,have been studied. One of them iden-tified as Arthrobacter globiformis andthe other as Micrococcus varians, pro-duce 3.4 and 2.6 g lysine per litreof medium.
文摘The genus Arthrobacter was established in 1947 by Conn & Dimmick. So far, more than 70 recognized?species of the genus Arthrobacter have been certified. Its special functions have been widely known by researchers, such as, in agricultural, in medical, in industrial, and in environmental areas, etc. What deserves to be mentioned is that some species of genus Arthrobacter have showed the function of degrading pesticides, fixing nitrogen, producing beneficial enzyme, treating sewage, and so on. Recently, the applications of the genus Arthrobacter, especially the VBNC?(viable but non-culturable) bacteria of this genus in the field of contaminated environment repair attract people’s attention and some related research results have also been obtained. The functions that we have known are waiting for us to study about mechanism, deeply. And, we can look forward to discovering more potential functions and applications of this genus in ecological environment. In the meantime, these discoveries must bring more new changes and knowledge.
文摘The removal of Cr(III) from aqueous Cr(III) using Arthrobacter nicotianae cells was examined. Cr(III) removal was strongly affected by the pH of the solution and the amounts of Cr(III) removed increased as the pH (1 - 5) of the solution increased. The removal of Cr(III) using the cells was also strongly affected by the Cr(III) concentration of the solution, and obeyed the Langmuir isotherm. The percentage of Cr increased as the cell quantity increased, whereas the amount of Cr (μmol/g dry wt. cells) decreased. The removal of Cr(III) using the cells was very fast, and reached an equilibrium within 6 h from the supply of Cr(III) in the solution. A small amount of Cr(III) absorbed by immobilized cells was desorbed at 30oC;however, most was desorbed at reflux temperature using diluted HCl. Cr(III) adsorption-desorption cycles can be repeated 5 times using immobilized cells. These results have practical implications for industrial wastewater management.
