A red-pigmented bacterial strain NS-17 was isolated from soil, and physiological and biochemical characteristics and 16S rDNA analysis established this organism as a strain of Serratia marcescens. The red pigment isol...A red-pigmented bacterial strain NS-17 was isolated from soil, and physiological and biochemical characteristics and 16S rDNA analysis established this organism as a strain of Serratia marcescens. The red pigment isolated from cells of NS-17 was identified as prodigiosin. By analyzing factors affecting the production of prodigiosin, modified medium and culture conditions were set up, and a continuous fermentation method was carried out to take advantage of the mass production of foam during fermentation. Continuous fermentation was achieved in the following conditions: 32℃, 1:1 ventilation ratio, and medium with a nutrient concentration 5-fold higher than that of the fermentation medium (with half the inorganic salt concentration) supplied as a feed medium at a flow rate of 8 mL/min. For the first time of continuous fermentation of Serratia marcescens coupling with foam flotation, a high yield of prodigiosin was obtained. After 56 h of culturing, the total harvest of cells was enhanced 2.33-fold compared to that of batch fermentation, the total amount of prodigiosin was enhanced 2.70-fold compared to that of batch fermentation, and cells and prodigiosin were concentrated in the efflux broth automatically.展开更多
Titanium based titanium dioxide （TiO2） nanotube arrays were prepared by electrochemical oxidation method, their microstructures were characterized, and the effects of sintering temperature and initial dye concentrat...Titanium based titanium dioxide （TiO2） nanotube arrays were prepared by electrochemical oxidation method, their microstructures were characterized, and the effects of sintering temperature and initial dye concentration and pH value on degradation performance of TiO2 nanotubc arrays wcrc investigated with methyl orange as a degradation object. The results showed that TiO2 nanotube arrays prepared by sintering at 500 ℃ exhibited good morphology and the highest photocata- lyric degradation efficiency; the degradation efficiency of the TiO2 nano material （500 ℃ ） to high concentration dye was higher than that to low concentration dye; the TiO2 nanotube array （500 ℃ ） exhibited higher degradation efficiency on dye solution at the pH of 3 than on that at the pH of 5.77 ; and the degradation efficien- cy of the TiO2 nanotube array （500 ℃） to 10 mg/L methyl orange solution （pH =3） reached 85.2%.展开更多
文摘A red-pigmented bacterial strain NS-17 was isolated from soil, and physiological and biochemical characteristics and 16S rDNA analysis established this organism as a strain of Serratia marcescens. The red pigment isolated from cells of NS-17 was identified as prodigiosin. By analyzing factors affecting the production of prodigiosin, modified medium and culture conditions were set up, and a continuous fermentation method was carried out to take advantage of the mass production of foam during fermentation. Continuous fermentation was achieved in the following conditions: 32℃, 1:1 ventilation ratio, and medium with a nutrient concentration 5-fold higher than that of the fermentation medium (with half the inorganic salt concentration) supplied as a feed medium at a flow rate of 8 mL/min. For the first time of continuous fermentation of Serratia marcescens coupling with foam flotation, a high yield of prodigiosin was obtained. After 56 h of culturing, the total harvest of cells was enhanced 2.33-fold compared to that of batch fermentation, the total amount of prodigiosin was enhanced 2.70-fold compared to that of batch fermentation, and cells and prodigiosin were concentrated in the efflux broth automatically.
基金Supported by Fund for Young and Middle-aged Teachers in Fujian Province(JA15880)National Spark Program Project(2015GA721002)
文摘Titanium based titanium dioxide （TiO2） nanotube arrays were prepared by electrochemical oxidation method, their microstructures were characterized, and the effects of sintering temperature and initial dye concentration and pH value on degradation performance of TiO2 nanotubc arrays wcrc investigated with methyl orange as a degradation object. The results showed that TiO2 nanotube arrays prepared by sintering at 500 ℃ exhibited good morphology and the highest photocata- lyric degradation efficiency; the degradation efficiency of the TiO2 nano material （500 ℃ ） to high concentration dye was higher than that to low concentration dye; the TiO2 nanotube array （500 ℃ ） exhibited higher degradation efficiency on dye solution at the pH of 3 than on that at the pH of 5.77 ; and the degradation efficien- cy of the TiO2 nanotube array （500 ℃） to 10 mg/L methyl orange solution （pH =3） reached 85.2%.
