This research was carried out to evaluate the relationship between the incorporation of calcite precipitation bacteria,sporosarcina pasteurii using calcium lactate as nutrient source and the properties of calcined cla...This research was carried out to evaluate the relationship between the incorporation of calcite precipitation bacteria,sporosarcina pasteurii using calcium lactate as nutrient source and the properties of calcined clay and limestone powder blended self-compacting concrete.Ten mixes were designed and designated S0 to S9 with S0 the control(without bacteria and nutrient)and S1 to S9 at varying bacteria and calcium lactate concentrations and the effect of the bacteria cell density and calcium lactate concentration on the compressive strength,sorptivity and tensile strength with age were evaluated using experimental program and statistical packages(ANOVA and post hoc tests).The result of both the experimental program and statistical evaluation shows that the incorporation of sporosarcina pasteurii and calcium lactate as nutrients had a positive impact on the properties of the ternary blended self-compacting concrete.展开更多
Objective Cr（VI） removal from industrial effluents and sediments has attracted the attention of environmental researchers. In the present study, we aimed to isolate bacteria for Cr（VI） bioremediation from sediment...Objective Cr（VI） removal from industrial effluents and sediments has attracted the attention of environmental researchers. In the present study, we aimed to isolate bacteria for Cr（VI） bioremediation from sediment samples and to optimize parameters of biodegradation. Methods Strains with the ability to tolerate Cr（VI） were obtained by serial dilution and spread plate methods and characterized by morphology, 16 S r DNA identification, and phylogenetic analysis. Cr（VI） was determined using the 1,5-diphenylcarbazide method, and the optimum p H and temperature for degradation were studied using a multiple-factor mixed experimental design. Statistical analysis methods were used to analyze the results. Results Fifty-five strains were obtained, and one strain（Sporosarcina saromensis M52; patent application number： 201410819443.3） having the ability to tolerate 500 mg Cr（VI）/L was selected to optimize the degradation conditions. M52 was found be able to efficiently remove 50-200 mg Cr（VI）/L in 24 h, achieving the highest removal efficiency at p H 7.0-8.5 and 35 °C. Moreover, M52 could completely degrade 100 mg Cr（VI）/L at p H 8.0 and 35 °C in 24 h. The mechanism involved in the reduction of Cr（VI） was considered to be bioreduction rather than absorption. Conclusion The strong degradation ability of S. saromensis M52 and its advantageous functional characteristics support the potential use of this organism for bioremediation of heavy metal pollution.展开更多
利用石蜡为惟一碳源从辽河油田油水样品中驯化筛选出一株强降解固体石蜡的菌R,初步鉴定为脲芽孢八叠球菌(Sporosarcina urea Kluyver and Niel)。该菌发酵液具有较强的排油活性及稳定的乳化能力,可使油水界面张力降低55.9%,其胞外生物...利用石蜡为惟一碳源从辽河油田油水样品中驯化筛选出一株强降解固体石蜡的菌R,初步鉴定为脲芽孢八叠球菌(Sporosarcina urea Kluyver and Niel)。该菌发酵液具有较强的排油活性及稳定的乳化能力,可使油水界面张力降低55.9%,其胞外生物表面活性剂被确定为阴离子型的水溶性产物。对其胞外脂肪酸进行了GC/MS的定性分析,确定其主要为十四酸、十六酸和十八酸。对该菌在水溶性不同的底物中培养,发现其细胞表面疏水性具有调适作用,推测该菌摄取烷烃的模式不是单一的。展开更多
文摘This research was carried out to evaluate the relationship between the incorporation of calcite precipitation bacteria,sporosarcina pasteurii using calcium lactate as nutrient source and the properties of calcined clay and limestone powder blended self-compacting concrete.Ten mixes were designed and designated S0 to S9 with S0 the control(without bacteria and nutrient)and S1 to S9 at varying bacteria and calcium lactate concentrations and the effect of the bacteria cell density and calcium lactate concentration on the compressive strength,sorptivity and tensile strength with age were evaluated using experimental program and statistical packages(ANOVA and post hoc tests).The result of both the experimental program and statistical evaluation shows that the incorporation of sporosarcina pasteurii and calcium lactate as nutrients had a positive impact on the properties of the ternary blended self-compacting concrete.
基金supported by the Xiamen Science and Technology Project of China[3502Z20123003]Fundamental Research Funds for the Central Universities of China[2011121006]National Undergraduate Training Program for Innovation and Entrepreneurship[201510384140]
文摘Objective Cr（VI） removal from industrial effluents and sediments has attracted the attention of environmental researchers. In the present study, we aimed to isolate bacteria for Cr（VI） bioremediation from sediment samples and to optimize parameters of biodegradation. Methods Strains with the ability to tolerate Cr（VI） were obtained by serial dilution and spread plate methods and characterized by morphology, 16 S r DNA identification, and phylogenetic analysis. Cr（VI） was determined using the 1,5-diphenylcarbazide method, and the optimum p H and temperature for degradation were studied using a multiple-factor mixed experimental design. Statistical analysis methods were used to analyze the results. Results Fifty-five strains were obtained, and one strain（Sporosarcina saromensis M52; patent application number： 201410819443.3） having the ability to tolerate 500 mg Cr（VI）/L was selected to optimize the degradation conditions. M52 was found be able to efficiently remove 50-200 mg Cr（VI）/L in 24 h, achieving the highest removal efficiency at p H 7.0-8.5 and 35 °C. Moreover, M52 could completely degrade 100 mg Cr（VI）/L at p H 8.0 and 35 °C in 24 h. The mechanism involved in the reduction of Cr（VI） was considered to be bioreduction rather than absorption. Conclusion The strong degradation ability of S. saromensis M52 and its advantageous functional characteristics support the potential use of this organism for bioremediation of heavy metal pollution.
文摘利用石蜡为惟一碳源从辽河油田油水样品中驯化筛选出一株强降解固体石蜡的菌R,初步鉴定为脲芽孢八叠球菌(Sporosarcina urea Kluyver and Niel)。该菌发酵液具有较强的排油活性及稳定的乳化能力,可使油水界面张力降低55.9%,其胞外生物表面活性剂被确定为阴离子型的水溶性产物。对其胞外脂肪酸进行了GC/MS的定性分析,确定其主要为十四酸、十六酸和十八酸。对该菌在水溶性不同的底物中培养,发现其细胞表面疏水性具有调适作用,推测该菌摄取烷烃的模式不是单一的。
