A mixed bacterial flora was isolated from the soil of two petroleum-contaminated sites, then cultivated and domesticated in an open environment. The bacteria were used to degrade engine oil in wastewater. The optimum ...A mixed bacterial flora was isolated from the soil of two petroleum-contaminated sites, then cultivated and domesticated in an open environment. The bacteria were used to degrade engine oil in wastewater. The optimum biodegradation conditions for all engine oil concentrations of respectively 489 mg L^-1, 1. 075 mg L^-1 and 2 088 mg L^-1 are bacterial inoculum concentration of 0.1%, temperature at 30 ℃ to 35 ℃, pH 7.0 to 7.5, and rotation at 190 r mia^-1 to 240 r rain^-1. The second-order kinetic model proposed by Quiroga and Sales describes the characteristics of the biodegradation of the engine oil very well. Engine oil concentration barely changes the growth rate of the bacterial consortium. The mixed bacterial flora has a high biodegrading capability for engine oil.展开更多
In this paper, the growth characteristics of Acidithiobacillus ferrooxidans （At.f） and Acidithiobacillus thiooxidans （At. f） in mixed culture has been studied, explored mixed bacteria phosphate solubilization effe...In this paper, the growth characteristics of Acidithiobacillus ferrooxidans （At.f） and Acidithiobacillus thiooxidans （At. f） in mixed culture has been studied, explored mixed bacteria phosphate solubilization effect, from a kind of low-grade phosphate rock. The results show that mixed bacteria has strong ability to produce acid, and have stronger oxidation activity to energy source -Fe^2＋. Mixed bacteria can significantly increase the rate of phosphate solubilization from phosphate rock in low concentration pulp. It goes against mixed bacteria reproduction when pulp concentration increased, makes phosphate solubilization rate decreased.展开更多
Bioleaching experiments combined with X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and scanning electron microscopy(SEM)were conducted to investigate three kinds of bornites from different regions leach...Bioleaching experiments combined with X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and scanning electron microscopy(SEM)were conducted to investigate three kinds of bornites from different regions leached by moderately thermophilic mixed bacteria of Leptospirillum ferriphilum YSK,Acidithiobacillus caldus D1 and Sulfobacillus thermosulfidooxidans ST.The results of bioleaching experiments showed that the leaching efficiency and the redox potential were significantly increased.The copper extraction efficiencies of three kinds of bornite maintained rapid growth until around the 12th day and no longer increased after the 18th,reaching 83.7%,96.5%and 86.6%,respectively.The XRD results of the leaching residue indicated that three kinds of bornites all produced jarosite in the late stage of leaching,and the leaching residues from of Daye Museum and Yunnan Geological Museum contained a mass of elemental sulfur.XPS analysis and scanning electron microscopy experiments showed that the surface of mineral particles was jarosite and the copper in the leaching residue was almost dissolved.展开更多
Background: Host genetic background and sex, play central roles in defining the pathogenesis of type 2 diabetes(T2 D), obesity and infectious diseases. Our previous studies demonstrated the utilization of genetically ...Background: Host genetic background and sex, play central roles in defining the pathogenesis of type 2 diabetes(T2 D), obesity and infectious diseases. Our previous studies demonstrated the utilization of genetically highly diverse inbred mouse lines, namely collaborative cross(CC), for dissecting host susceptibility for the development of T2 D and obesity, showing significant variations following high-fat(42% fat) diet(HFD). Here, we aimed to assessing the host genetic background and sex effects on T2 D and obesity development in response to oral-mixed bacterial infection and HFD using the CC lines.Materials and Methods: Study cohort consists of 97 mice from 2 CC lines(both sexes), maintained on either HFD or Standard diet(CHD) for 12 weeks. At week 5 a group of mice from each diet were infected with Porphyromonas gingivalis(Pg) and Fusobacterium nucleatum(Fn) bacteria(control groups without infection). Body weight(BW) and glucose tolerance ability were assessed at the end time point of the experiment.Results: The CC lines varied(P <.05) at their BW gain and glucose tolerance ability(with sex effect) in response to diets and/or infection, showing opposite responses despite sharing the same environmental conditions. The combination of diet and infection enhances BW accumulation for IL1912, while restraints it for IL72. As for glucose tolerance ability, only females(both lines) were deteriorated in response to infection.Conclusions: This study emphasizes the power of the CC mouse population for the characterization of host genetic makeup for defining the susceptibility of the individual to development of obesity and/or impaired glucose tolerance.展开更多
The effect of process parameters （pH, pulp density, inoculum volume, ferrous content, particle size） on the rate of copper solubilization was analyzed respectively through bioleaching tests with mixed bacteria in sh...The effect of process parameters （pH, pulp density, inoculum volume, ferrous content, particle size） on the rate of copper solubilization was analyzed respectively through bioleaching tests with mixed bacteria in shake flasks. These results show that the optimal process parameters are： pH, 1.50-1.80; pulp density, 5wt%; inoculum volume, 10vol%; ferrous content, 2g·L^-1; particle size, 〈0.076 mm. Furthermore, when the pH value is below 1.50 in leaching solution, the iron precipitated can be reduced to a great extent, but it shows low bacterial activity at this pH. Finally, it is emphasized that the optimal parameters are also determined by economical benefit.展开更多
The elementary and phase analysis of discarded copper ores from Yongping of China has been performed. The experi- ments of extracting copper from the discarded copper ores were done with the mixed bacteria obtained th...The elementary and phase analysis of discarded copper ores from Yongping of China has been performed. The experi- ments of extracting copper from the discarded copper ores were done with the mixed bacteria obtained through a series of enrichment, separation, domestication and combination tests. The results show that in the process of bioleaching, the pH value rises at first and drops gradually. The Eh value keeps rising along with the time and the appropriate Eh value varying between 750 and 800 mV will benefit the bioleaching copper. The high concentration of ferric ions is detrimental to the bioleaching copper. The results of bioleaching copper are good. That is, the copper recovery is 31.8% after 27 days.展开更多
The aim of the current study was to investigate the effects of a lactic acid bacteria inoculant（Lactobacillus plantarum, LP）, fibrolytic enzyme（EN）, combination of LP and EN（LP＋EN） on fermentation quality, nutr...The aim of the current study was to investigate the effects of a lactic acid bacteria inoculant（Lactobacillus plantarum, LP）, fibrolytic enzyme（EN）, combination of LP and EN（LP＋EN） on fermentation quality, nutritive characteristics and in vitro digestibility of total mixed ration（TMR） silages containing 0, 7.5 and 15.0%（on dry matter basis） of rape（Brassica campestris L.） straw（RS）（denoted as CTMR, LTMR and MTMR, respectively）. After ensiling for 60 days, TMR silages without additives were well preserved, but MTMR had higher p H than CTMR and LTMR. There were no differences in other parameters of fermentation quality, microbial composition, nutrition and in vitro digestibility between CTMR and LTMR except for yeast and mold number and crude protein（CP） content. CTMR and LTMR silage had higher CP content, in vitro neutral detergent fiber digestibility（IVNDFD） and in vitro acid detergent fiber digestibility（IVADFD）, lower acid detergent fiber（ADF） content than MTMR silage. LP and EN decreased p H and increased dry matter（DM） recovery of TMR silages. LP＋EN improved the fermentation quality, nutritive characteristics and in vitro digestibility of TMR silages, showed by lower p H, ADF content, higher lactic acid content, in vitro dry matter digestibility（IVDMD） and IVNDFD. Therefore, It was suggested that TMR silage contained 7.5% RS on a DM basis and treated with LP＋EN can be as a useful feed for ruminant.展开更多
基金Funded by the Natural Science Foundation of China (No.40571145).
文摘A mixed bacterial flora was isolated from the soil of two petroleum-contaminated sites, then cultivated and domesticated in an open environment. The bacteria were used to degrade engine oil in wastewater. The optimum biodegradation conditions for all engine oil concentrations of respectively 489 mg L^-1, 1. 075 mg L^-1 and 2 088 mg L^-1 are bacterial inoculum concentration of 0.1%, temperature at 30 ℃ to 35 ℃, pH 7.0 to 7.5, and rotation at 190 r mia^-1 to 240 r rain^-1. The second-order kinetic model proposed by Quiroga and Sales describes the characteristics of the biodegradation of the engine oil very well. Engine oil concentration barely changes the growth rate of the bacterial consortium. The mixed bacterial flora has a high biodegrading capability for engine oil.
文摘In this paper, the growth characteristics of Acidithiobacillus ferrooxidans （At.f） and Acidithiobacillus thiooxidans （At. f） in mixed culture has been studied, explored mixed bacteria phosphate solubilization effect, from a kind of low-grade phosphate rock. The results show that mixed bacteria has strong ability to produce acid, and have stronger oxidation activity to energy source -Fe^2＋. Mixed bacteria can significantly increase the rate of phosphate solubilization from phosphate rock in low concentration pulp. It goes against mixed bacteria reproduction when pulp concentration increased, makes phosphate solubilization rate decreased.
基金Project(51974363)supported by the National Natural Science Foundation of China。
文摘Bioleaching experiments combined with X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD)and scanning electron microscopy(SEM)were conducted to investigate three kinds of bornites from different regions leached by moderately thermophilic mixed bacteria of Leptospirillum ferriphilum YSK,Acidithiobacillus caldus D1 and Sulfobacillus thermosulfidooxidans ST.The results of bioleaching experiments showed that the leaching efficiency and the redox potential were significantly increased.The copper extraction efficiencies of three kinds of bornite maintained rapid growth until around the 12th day and no longer increased after the 18th,reaching 83.7%,96.5%and 86.6%,respectively.The XRD results of the leaching residue indicated that three kinds of bornites all produced jarosite in the late stage of leaching,and the leaching residues from of Daye Museum and Yunnan Geological Museum contained a mass of elemental sulfur.XPS analysis and scanning electron microscopy experiments showed that the surface of mineral particles was jarosite and the copper in the leaching residue was almost dissolved.
基金Israeli Science Foundation (ISF),Grant/Award Number 1085/18German Israeli Science Foundation (GIF),Grant/Award Number I-63-410.20-2017+1 种基金Binational Science Foundation (BSF),Grant/Award Number 2015077Tel-Aviv University
文摘Background: Host genetic background and sex, play central roles in defining the pathogenesis of type 2 diabetes(T2 D), obesity and infectious diseases. Our previous studies demonstrated the utilization of genetically highly diverse inbred mouse lines, namely collaborative cross(CC), for dissecting host susceptibility for the development of T2 D and obesity, showing significant variations following high-fat(42% fat) diet(HFD). Here, we aimed to assessing the host genetic background and sex effects on T2 D and obesity development in response to oral-mixed bacterial infection and HFD using the CC lines.Materials and Methods: Study cohort consists of 97 mice from 2 CC lines(both sexes), maintained on either HFD or Standard diet(CHD) for 12 weeks. At week 5 a group of mice from each diet were infected with Porphyromonas gingivalis(Pg) and Fusobacterium nucleatum(Fn) bacteria(control groups without infection). Body weight(BW) and glucose tolerance ability were assessed at the end time point of the experiment.Results: The CC lines varied(P <.05) at their BW gain and glucose tolerance ability(with sex effect) in response to diets and/or infection, showing opposite responses despite sharing the same environmental conditions. The combination of diet and infection enhances BW accumulation for IL1912, while restraints it for IL72. As for glucose tolerance ability, only females(both lines) were deteriorated in response to infection.Conclusions: This study emphasizes the power of the CC mouse population for the characterization of host genetic makeup for defining the susceptibility of the individual to development of obesity and/or impaired glucose tolerance.
基金This study is supported by the Educational Science Fund of Jiangxi Province, China (No.200202).
文摘The effect of process parameters （pH, pulp density, inoculum volume, ferrous content, particle size） on the rate of copper solubilization was analyzed respectively through bioleaching tests with mixed bacteria in shake flasks. These results show that the optimal process parameters are： pH, 1.50-1.80; pulp density, 5wt%; inoculum volume, 10vol%; ferrous content, 2g·L^-1; particle size, 〈0.076 mm. Furthermore, when the pH value is below 1.50 in leaching solution, the iron precipitated can be reduced to a great extent, but it shows low bacterial activity at this pH. Finally, it is emphasized that the optimal parameters are also determined by economical benefit.
文摘The elementary and phase analysis of discarded copper ores from Yongping of China has been performed. The experi- ments of extracting copper from the discarded copper ores were done with the mixed bacteria obtained through a series of enrichment, separation, domestication and combination tests. The results show that in the process of bioleaching, the pH value rises at first and drops gradually. The Eh value keeps rising along with the time and the appropriate Eh value varying between 750 and 800 mV will benefit the bioleaching copper. The high concentration of ferric ions is detrimental to the bioleaching copper. The results of bioleaching copper are good. That is, the copper recovery is 31.8% after 27 days.
基金supported by the Natural Science Foundation of the Jiangsu Province for Young Scholars,China(BK20130694)the Specialized Research Fund for the Doctoral Program of Higher Education,China(20130097120053)+1 种基金the National Natural Science Foundation of China(31502014)the Project of Jiangsu Independent Innovation,China(CX(15)1003)
文摘The aim of the current study was to investigate the effects of a lactic acid bacteria inoculant（Lactobacillus plantarum, LP）, fibrolytic enzyme（EN）, combination of LP and EN（LP＋EN） on fermentation quality, nutritive characteristics and in vitro digestibility of total mixed ration（TMR） silages containing 0, 7.5 and 15.0%（on dry matter basis） of rape（Brassica campestris L.） straw（RS）（denoted as CTMR, LTMR and MTMR, respectively）. After ensiling for 60 days, TMR silages without additives were well preserved, but MTMR had higher p H than CTMR and LTMR. There were no differences in other parameters of fermentation quality, microbial composition, nutrition and in vitro digestibility between CTMR and LTMR except for yeast and mold number and crude protein（CP） content. CTMR and LTMR silage had higher CP content, in vitro neutral detergent fiber digestibility（IVNDFD） and in vitro acid detergent fiber digestibility（IVADFD）, lower acid detergent fiber（ADF） content than MTMR silage. LP and EN decreased p H and increased dry matter（DM） recovery of TMR silages. LP＋EN improved the fermentation quality, nutritive characteristics and in vitro digestibility of TMR silages, showed by lower p H, ADF content, higher lactic acid content, in vitro dry matter digestibility（IVDMD） and IVNDFD. Therefore, It was suggested that TMR silage contained 7.5% RS on a DM basis and treated with LP＋EN can be as a useful feed for ruminant.
