Bacteria cells with different standard shapes are well suited for use as templates for the fabrication of magnetic and electrically conductive microstructures. In this paper, metallization of bacteria cells is demonst...Bacteria cells with different standard shapes are well suited for use as templates for the fabrication of magnetic and electrically conductive microstructures. In this paper, metallization of bacteria cells is demonstrated by an electroless deposition technique of nickel-phosphorus initiated by colloid palladium-tin catalyst on the surfaces of Citeromyces matritensis and Bacillus cereus. The activated and metallized bacteria cells have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). Results showed that both Citeromyces matritensis and Bacillus cereus had no deformation in shape after metallization; the metallized films deposited on the surfaces of bacteria cells are homogeneous in thickness and noncrystalline in phase structure. The kinetics of colloid palladium-tin solution and electroless plating on bacteria cells is discussed.展开更多
In steady state, the intestinal epithelium forms an important part of the gut barrier to defend against luminal bacterial attack. However, the intestinal epithelium is compromised by ionizing irradiation due to its in...In steady state, the intestinal epithelium forms an important part of the gut barrier to defend against luminal bacterial attack. However, the intestinal epithelium is compromised by ionizing irradiation due to its inherent selfrenewing capacity. In this process, small intestinal bacterial overgrowth is a critical event that reciprocally alters the immune milieu. In other words, intestinal bacterial dysbiosis induces inflammation in response to intestinal injuries, thus influencing the repair process of irradiated lesions. In fact, it is accepted that commensal bacteria can generally enhance the host radiation sensitivity. To address the determination of radiation sensitivity, we hypothesize that Paneth cells press a critical "button" because these cells are central to intestinal health and disease by using their peptides, which are responsible for controlling stem cell development in the small intestine and luminal bacterial diversity. Herein,the most important question is whether Paneth cells alter their secretion profiles in the situation of ionizing irradiation. On this basis, the tolerance of Paneth cells to ionizing radiation and related mechanisms by which radiation affects Paneth cell survival and death will be discussed in this review. We hope that the relevant results will be helpful in developing new approaches against radiation enteropathy.展开更多
The current study has been undertaken to examine the beneficial effect in the power output of a microbial fuel cell (MFC) by adding cellulolytic bacteria Ruminococcus albus (R. albus) into the anodic chamber. Mediator...The current study has been undertaken to examine the beneficial effect in the power output of a microbial fuel cell (MFC) by adding cellulolytic bacteria Ruminococcus albus (R. albus) into the anodic chamber. Mediator-less H-type MFCs were set up where the anode chamber contained anaerobic digester microorganisms as inocula on finely ground pine tree (Avicel) at 2% (w/v) and the cathode chamber of 10mM phosphate buffered saline conductive solution, both separated by a cation exchange membrane. The functioning of the MFCs for generation of electrical power and the amounts of gaseous byproducts was monitored over a 9-day period. The addition of cellulolytic bacteria caused an increase of average power density from 7.9 m W/m2 to19.5 m W/m2, about 245% increase over a 9-day period. For both groups of MFCs;with R. albus and the control, the head space gases collected were methane and CO2. While the methane: CO2 ratios were found unchanged at 1.7:1 throughout the 9 days of operation, the total gas production increased from 248 mL to 319 mL due to the presence of R. albus addition. This study confirms that whereas the biocatalytic activity of anode microbial population determines the energy production, the addition of external cellulolytic bacteria into anode microbial population can improve and extend the biomass utilization.展开更多
Objective In order to use facultative gut bacteria as an alternate to animals for the initial gastrointestinal toxicity screening of heavy metals, a comparative study on rat intestinal epithelial cells and resident gu...Objective In order to use facultative gut bacteria as an alternate to animals for the initial gastrointestinal toxicity screening of heavy metals, a comparative study on rat intestinal epithelial cells and resident gut bacteria was undertaken. Methods in vitro growth rate of four gut bacteria, dehydrogenase （DHA） and esterase （EA） activity test, intestinal epithelial and bacterial cell membrane enzymes and in situ effect of arsenite were analysed. Results Growth profile of mixed resident population of gut bacteria and pure isolates of Escherichia coli, Pseudomonas sp., Lactobacillus sp., and Staphylococcus sp. revealed an arsenite （2-20 ppm） concentration-dependent inhibition. The viability pattern of epithelial cells also showed similar changes. DHA and EA tests revealed significant inhibition （40%-72%） with arsenite exposure of 5 and 10 ppm in isolated gut bacteria and epithelial cells. Decrease in membrane alkaline phosphatase and Ca^2＋-Mg^2＋-ATPase activities was in the range of 33%-55% in four bacteria at the arsenite exposure of 10 ppm, whereas it was 60%-65% in intestinal epithelial villus cells, in situ incubation of arsenite using intestinal loops also showed more or less similar changes in membrane enzymes of resident gut bacterial population and epithelial cells. Conclusion The results indicate that facultative gut bacteria can be used as suitable in vitro model for the preliminary screening of arsenical gastrointestinal cytotoxic effects.展开更多
The present study aimed at isolation characterization and evaluation of electrogenic bacteria for electricity generation using waste water. In this context, waste water samples were collected from University of Nizwa ...The present study aimed at isolation characterization and evaluation of electrogenic bacteria for electricity generation using waste water. In this context, waste water samples were collected from University of Nizwa waste water treatment plant. A total of eight distinct bacterial isolates were isolated from these samples by serial dilution and plating on LB Agar medium. The bacterial isolates were than grown at different temperatures and pH. DNA from bacterial samples was isolated and 16S rRNA gene amplification was carried out. The 16S rRNA gene PCR products were directly sequenced and the resulting sequence was blasted using BLASTn. Based on BLAST results, the bacterial strains were identified. The bacteria were used in different combinations to generate electricity from waste water in microbial fuel cells constructed using plastic bottles. The microbial isolates were found to produce varying levels of currents and their electrogenic potential in waste water was observed to increase with the passage of time.展开更多
本研究通过Lactobacillus plantarum P-S1016发酵黑莓汁,测定菌株生长动力学参数,并对黑莓汁有机酸、风味物质和电子舌评分进行分析;以皮质酮为诱导剂建立PC12细胞损伤模型,测定细胞活力、活性氧水平、细胞凋亡率和线粒体膜电位,探究发...本研究通过Lactobacillus plantarum P-S1016发酵黑莓汁,测定菌株生长动力学参数,并对黑莓汁有机酸、风味物质和电子舌评分进行分析;以皮质酮为诱导剂建立PC12细胞损伤模型,测定细胞活力、活性氧水平、细胞凋亡率和线粒体膜电位,探究发酵黑莓汁对皮质酮损伤细胞的保护作用。结果表明,L.plantarum P-S1016生长动力学模型拟合度R2为0.943,表明模型拟合良好,29.28 h时菌体浓度达到最大值9.40(lg(CFU/mL));经过发酵黑莓汁中的乳酸和琥珀酸质量浓度分别为38.99 mg/mL和3.30 mg/mL,酯、醇、酸及其他风味成分含量均有增加,醇类物质占比最高(33.28%),其次是烷类(29.80%),黑莓汁的咸味口感明显降低;此外,质量浓度50、200μg/mL的发酵黑莓汁冻干样可显著提高皮质酮诱导下细胞相对存活率,使其提高至(1.48±0.07)倍和(1.60±0.01)倍,降低细胞内活性氧水平、晚期凋亡和坏死细胞占比,抑制线粒体膜电位下降。综上所述,L.plantarum P-S1016可应用于黑莓汁发酵,赋予其更好的口感和风味品质,使其具有更强的神经保护潜力。本研究制得的发酵黑莓汁有望成为新型功能性天然植物基产品,对于提高黑莓鲜果的食用特性与功能价值有一定的现实意义。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.59975007).
文摘Bacteria cells with different standard shapes are well suited for use as templates for the fabrication of magnetic and electrically conductive microstructures. In this paper, metallization of bacteria cells is demonstrated by an electroless deposition technique of nickel-phosphorus initiated by colloid palladium-tin catalyst on the surfaces of Citeromyces matritensis and Bacillus cereus. The activated and metallized bacteria cells have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD). Results showed that both Citeromyces matritensis and Bacillus cereus had no deformation in shape after metallization; the metallized films deposited on the surfaces of bacteria cells are homogeneous in thickness and noncrystalline in phase structure. The kinetics of colloid palladium-tin solution and electroless plating on bacteria cells is discussed.
基金National Natural Science Foundation of China,No.81874254 and No.81773353。
文摘In steady state, the intestinal epithelium forms an important part of the gut barrier to defend against luminal bacterial attack. However, the intestinal epithelium is compromised by ionizing irradiation due to its inherent selfrenewing capacity. In this process, small intestinal bacterial overgrowth is a critical event that reciprocally alters the immune milieu. In other words, intestinal bacterial dysbiosis induces inflammation in response to intestinal injuries, thus influencing the repair process of irradiated lesions. In fact, it is accepted that commensal bacteria can generally enhance the host radiation sensitivity. To address the determination of radiation sensitivity, we hypothesize that Paneth cells press a critical "button" because these cells are central to intestinal health and disease by using their peptides, which are responsible for controlling stem cell development in the small intestine and luminal bacterial diversity. Herein,the most important question is whether Paneth cells alter their secretion profiles in the situation of ionizing irradiation. On this basis, the tolerance of Paneth cells to ionizing radiation and related mechanisms by which radiation affects Paneth cell survival and death will be discussed in this review. We hope that the relevant results will be helpful in developing new approaches against radiation enteropathy.
文摘The current study has been undertaken to examine the beneficial effect in the power output of a microbial fuel cell (MFC) by adding cellulolytic bacteria Ruminococcus albus (R. albus) into the anodic chamber. Mediator-less H-type MFCs were set up where the anode chamber contained anaerobic digester microorganisms as inocula on finely ground pine tree (Avicel) at 2% (w/v) and the cathode chamber of 10mM phosphate buffered saline conductive solution, both separated by a cation exchange membrane. The functioning of the MFCs for generation of electrical power and the amounts of gaseous byproducts was monitored over a 9-day period. The addition of cellulolytic bacteria caused an increase of average power density from 7.9 m W/m2 to19.5 m W/m2, about 245% increase over a 9-day period. For both groups of MFCs;with R. albus and the control, the head space gases collected were methane and CO2. While the methane: CO2 ratios were found unchanged at 1.7:1 throughout the 9 days of operation, the total gas production increased from 248 mL to 319 mL due to the presence of R. albus addition. This study confirms that whereas the biocatalytic activity of anode microbial population determines the energy production, the addition of external cellulolytic bacteria into anode microbial population can improve and extend the biomass utilization.
文摘Objective In order to use facultative gut bacteria as an alternate to animals for the initial gastrointestinal toxicity screening of heavy metals, a comparative study on rat intestinal epithelial cells and resident gut bacteria was undertaken. Methods in vitro growth rate of four gut bacteria, dehydrogenase （DHA） and esterase （EA） activity test, intestinal epithelial and bacterial cell membrane enzymes and in situ effect of arsenite were analysed. Results Growth profile of mixed resident population of gut bacteria and pure isolates of Escherichia coli, Pseudomonas sp., Lactobacillus sp., and Staphylococcus sp. revealed an arsenite （2-20 ppm） concentration-dependent inhibition. The viability pattern of epithelial cells also showed similar changes. DHA and EA tests revealed significant inhibition （40%-72%） with arsenite exposure of 5 and 10 ppm in isolated gut bacteria and epithelial cells. Decrease in membrane alkaline phosphatase and Ca^2＋-Mg^2＋-ATPase activities was in the range of 33%-55% in four bacteria at the arsenite exposure of 10 ppm, whereas it was 60%-65% in intestinal epithelial villus cells, in situ incubation of arsenite using intestinal loops also showed more or less similar changes in membrane enzymes of resident gut bacterial population and epithelial cells. Conclusion The results indicate that facultative gut bacteria can be used as suitable in vitro model for the preliminary screening of arsenical gastrointestinal cytotoxic effects.
文摘The present study aimed at isolation characterization and evaluation of electrogenic bacteria for electricity generation using waste water. In this context, waste water samples were collected from University of Nizwa waste water treatment plant. A total of eight distinct bacterial isolates were isolated from these samples by serial dilution and plating on LB Agar medium. The bacterial isolates were than grown at different temperatures and pH. DNA from bacterial samples was isolated and 16S rRNA gene amplification was carried out. The 16S rRNA gene PCR products were directly sequenced and the resulting sequence was blasted using BLASTn. Based on BLAST results, the bacterial strains were identified. The bacteria were used in different combinations to generate electricity from waste water in microbial fuel cells constructed using plastic bottles. The microbial isolates were found to produce varying levels of currents and their electrogenic potential in waste water was observed to increase with the passage of time.
