Cultivable magnetotactic bacteria(MTB) in laboratory can provide sufficient samples for molecular microbiological and magnetic studies.However,a cold-stored MTB strain,such as Magnetospirillum magneticum AMB-1,often l...Cultivable magnetotactic bacteria(MTB) in laboratory can provide sufficient samples for molecular microbiological and magnetic studies.However,a cold-stored MTB strain,such as Magnetospirillum magneticum AMB-1,often loses its ability to synthesize magnetosomes and consequently fails to sense the external magnetic field.It is therefore important to quickly recover vigorous bacteria cells that highly capable of magnetosome producing.In this study,a modified capillary magnetic separation system was designed to recover a deteriorating strain of Magnetospirillum magneticum AMB-1 that long-term cold-stored in a refrigerator.The results show that all cells obtained after a 3-cycle treatment were vigorous and had the ability to produce magnetosomes.Moreover,the 3rd-cycle recovered cells were able to form more magnetosome crystals.Compared with the colony formation method,this new method is time-saving,easily operated,and more efficient for recovering vigorous MTB cells.展开更多
In this study, the feasibility of using chitosan, a multifunctional environmentally friendly biopolymer, at different molecular weights to simultaneously adsorb various metal ions from aqueous solutions was evaluated....In this study, the feasibility of using chitosan, a multifunctional environmentally friendly biopolymer, at different molecular weights to simultaneously adsorb various metal ions from aqueous solutions was evaluated. The experiments were carried out to estimate adsorptivity and selectivity of three molecular weights chitosan, 3.60 × 105 （Chl）, 5.97 × 105 （Ch2） and 9.47 × 105 （Ch3） g/mol, towards Cu（II）, Ni（II）, and Pb（II） ions in aqueous solutions. Experimental results indicated that chitosan of high molecular weight （Ch3） was the best at adsorption capacity than the others. On chitosan solutions followed by Ni（II） and then Cu（II）. the other hand, Pb（lI） had the highest adsorption ability in the three展开更多
Phosphate-solubilizing bacterial strains(6 Nos.) were isolated from the rhizosphere soils of two seagrasses(Halophila ovalis(R.Br.) Hook and Halodule pinifolia(Miki) Hartog) in the Vellar estuary.Experimental studies ...Phosphate-solubilizing bacterial strains(6 Nos.) were isolated from the rhizosphere soils of two seagrasses(Halophila ovalis(R.Br.) Hook and Halodule pinifolia(Miki) Hartog) in the Vellar estuary.Experimental studies found that the strain PSSG6 was effective in phosphate solubilization with Phosphate Solubilization efficiency index E = 375 ± 8.54,followed by the strain PSSG5 with Phosphate Solubilization efficiency index E = 275 ± 27.3.Of the 6 strains isolated,the strains PSSG4 and PSSG5 be-longed to the genus Bacillus,and PSSG1,PSSG2 and PSSG3 were identified as Citrobacter sp.,Shigella sp.,and Klebsiella sp.,respectively,by conventional method,and PSSG6 was identified as Bacillus circulans using conventional and molecular methods.展开更多
Fungal diseases often occur seriously in muskmelon in open field of Hubei Province in summer, especially in continuous cropping pattern, resulting in great economic losses. In this study, the pathogens of main fungal ...Fungal diseases often occur seriously in muskmelon in open field of Hubei Province in summer, especially in continuous cropping pattern, resulting in great economic losses. In this study, the pathogens of main fungal diseases in muskmelon in open field of Hubei Province were isolated, and they were identified by morphological and molecular techniques. The results showed that muskmelon fusarium wilt is a major disease in muskmelon in open field of Hubei Province in summer, and its pathogen was confirmed to be Fusarium oxysporum. In future studies, one pair of specific primers would be designed to detect different pathogenic races of Fusarium oxysporum so as to accelerate the detection and to shorten the detection time,thereby proving guidance for actual production.展开更多
With the development of colloid interface and enzyme technologies,enzyme-containing reversed micellar system has been receiving much attention in bioseparation and bioconversion. Because of its high efficiency,it has ...With the development of colloid interface and enzyme technologies,enzyme-containing reversed micellar system has been receiving much attention in bioseparation and bioconversion. Because of its high efficiency,it has brought new opportunities for the development of molecular biotechnology. Reversed micelles represent nano-sized aqueous droplets stabilized by surfactant amphiphiles inside the bulk organic solvents. The entrapped enzymes have enhanced activities under those conditions as suited in the lipid bilayers of biological membranes. The fundamentals of enzyme-containing reversed micellar system are described in this paper,with special emphasis on the effects of surfactants varying in concentrations and structures. The latest study progress on the surfactants application in enzyme-containing reversed micelles is reviewed. The introduction of novel functional surfactants in micellar enzymology and their future development are also discussed.展开更多
基金Supported by the Natural Science Foundation of Shandong Province,China(No.2006ZRB01973)the National Natural Science Foundation of China(Nos.40821091,40325011)
文摘Cultivable magnetotactic bacteria(MTB) in laboratory can provide sufficient samples for molecular microbiological and magnetic studies.However,a cold-stored MTB strain,such as Magnetospirillum magneticum AMB-1,often loses its ability to synthesize magnetosomes and consequently fails to sense the external magnetic field.It is therefore important to quickly recover vigorous bacteria cells that highly capable of magnetosome producing.In this study,a modified capillary magnetic separation system was designed to recover a deteriorating strain of Magnetospirillum magneticum AMB-1 that long-term cold-stored in a refrigerator.The results show that all cells obtained after a 3-cycle treatment were vigorous and had the ability to produce magnetosomes.Moreover,the 3rd-cycle recovered cells were able to form more magnetosome crystals.Compared with the colony formation method,this new method is time-saving,easily operated,and more efficient for recovering vigorous MTB cells.
文摘In this study, the feasibility of using chitosan, a multifunctional environmentally friendly biopolymer, at different molecular weights to simultaneously adsorb various metal ions from aqueous solutions was evaluated. The experiments were carried out to estimate adsorptivity and selectivity of three molecular weights chitosan, 3.60 × 105 （Chl）, 5.97 × 105 （Ch2） and 9.47 × 105 （Ch3） g/mol, towards Cu（II）, Ni（II）, and Pb（II） ions in aqueous solutions. Experimental results indicated that chitosan of high molecular weight （Ch3） was the best at adsorption capacity than the others. On chitosan solutions followed by Ni（II） and then Cu（II）. the other hand, Pb（lI） had the highest adsorption ability in the three
文摘Phosphate-solubilizing bacterial strains(6 Nos.) were isolated from the rhizosphere soils of two seagrasses(Halophila ovalis(R.Br.) Hook and Halodule pinifolia(Miki) Hartog) in the Vellar estuary.Experimental studies found that the strain PSSG6 was effective in phosphate solubilization with Phosphate Solubilization efficiency index E = 375 ± 8.54,followed by the strain PSSG5 with Phosphate Solubilization efficiency index E = 275 ± 27.3.Of the 6 strains isolated,the strains PSSG4 and PSSG5 be-longed to the genus Bacillus,and PSSG1,PSSG2 and PSSG3 were identified as Citrobacter sp.,Shigella sp.,and Klebsiella sp.,respectively,by conventional method,and PSSG6 was identified as Bacillus circulans using conventional and molecular methods.
基金Supported by Earmarked Fund for China Agriculture Research System(CARS-26-34)
文摘Fungal diseases often occur seriously in muskmelon in open field of Hubei Province in summer, especially in continuous cropping pattern, resulting in great economic losses. In this study, the pathogens of main fungal diseases in muskmelon in open field of Hubei Province were isolated, and they were identified by morphological and molecular techniques. The results showed that muskmelon fusarium wilt is a major disease in muskmelon in open field of Hubei Province in summer, and its pathogen was confirmed to be Fusarium oxysporum. In future studies, one pair of specific primers would be designed to detect different pathogenic races of Fusarium oxysporum so as to accelerate the detection and to shorten the detection time,thereby proving guidance for actual production.
基金supported by the National Natural Science Foundation of China (50978087,50978088 and 51039001)the Program for Changjiang Scholars and Innovative Research Team in University (IRT0719)+1 种基金the Hu-nan Provincial Natural Science Foundation of China (10JJ7005)the Hunan Key Scientific Research Project (2009FJ1010)
文摘With the development of colloid interface and enzyme technologies,enzyme-containing reversed micellar system has been receiving much attention in bioseparation and bioconversion. Because of its high efficiency,it has brought new opportunities for the development of molecular biotechnology. Reversed micelles represent nano-sized aqueous droplets stabilized by surfactant amphiphiles inside the bulk organic solvents. The entrapped enzymes have enhanced activities under those conditions as suited in the lipid bilayers of biological membranes. The fundamentals of enzyme-containing reversed micellar system are described in this paper,with special emphasis on the effects of surfactants varying in concentrations and structures. The latest study progress on the surfactants application in enzyme-containing reversed micelles is reviewed. The introduction of novel functional surfactants in micellar enzymology and their future development are also discussed.
