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Abstract  

A microcalorimetric technique based on the bacterial heat-output was explored to evaluate the effect of Mn(II) on Bacillus thuringiensis. The power-time curves of the growth metabolism of B. thuringiensis and the effect of Mn(II) on it were studied using an LKB-2277 BioActivity Monitor, ampoules method, at 28C. For evaluation of the results, the maximum peak-heat output power (P max) in the growth phase, the growth rate constants (k), the log phase heat effects (Q log ), and the total heat effect in 23 h (Q T) for B. thuringiensis were determined. Manganese has been regarded as the essential biological trace element. Mn(II) of different concentration have different effects on B. thuringiensis growth metabolism. High concentration (800-1600 μg mL-1) of Mn(II) can promote the growth of B. thuringiensis; low concentration (500-800 μg mL-1) can inhabit its growth.

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Abstract  

Power-time curves and metabolic properties of Tetrahymena thermophila BF5 exposed to different Yb3+ levels were studied by ampoule method of isothermal calorimetry at 28°C. Metabolic rate (r) decreased significantly while peak time (PT) increased with the increase of Yb3+. These results were mainly due to the inhibition of cell growth, which corresponded to the decrease of cell number obtained by cell counting. Compared with cell counting, calorimetry was sensible, easy to use and convenient for monitoring the toxic effects of Yb3+ on cells and freshwater ecosystem. It was also found that cell membrane fluidity decreased significantly under the effects of Yb3+, which indicated that Yb3+ could be membrane active molecules with its effect on cell membranes as fundamental aspect of its toxicity.

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Pot experiments using loamy soil were conducted to evaluate the effect of irrigation with industrial effluents on growth, uptake on growth, uptake of nutrients and yield of wheat (Triticum aestivumGiza 164) as a monocot and faba beans (Vicia fabaGiza 461) as a dicot plant. Also, irrigation by industrial effluents in combination with vesicular-arbuscular mycorrhiza (VAM) was used in trying to use a biological control to overcome the harmful effects of heavy metals pollution. Irrigation of plants with industrial effluents leads to marked changes in growth criteria depending on plant and/or the stage of growth. Industrial wastewater led also to marked changes in total carbohydrates and nitrogen in both shoots and roots. On the other hand, combination of industrial waste water with VAM caused an increase in the total carbohydrates and total nitrogen in shoots and roots of both wheat and bean plants. The yield components in wheat and bean were significantly increased with industrial effluents, but the biochemical concentrations were different. In wheat, the carbohydrate concentrations were increased, but protein- N and total-N were decreased, however mineral contents, especially ZN were increased. The reverse response was recorded with VAM. For bean the opposite occurred. Generally, bean plants were more sensitive to pollution with heavy metals, than those of wheat however this could influence be overcome by using VAM with irrigation.

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. Effects of artesunate on the growth metabolism of Escherichia coli Artesunate was dissolved in N , N -dimethylformamide for preparation of 25, 15, 10, 5, and 0.5 mg/mL solution. An accurately measured volume solution (concentration

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Journal of Thermal Analysis and Calorimetry
Authors: Liu Yongjun, Ding Yangjun, Nan Zhaodong, Sun Haitao, and Zhang Honglin

Abstract  

The power-time curves of bacterial growth at different temperatures were determined by using the 2277 Thermal Activity Monitor (Sweden). From these curves, the growth rate constant (μ) and activation energy (E a) were calculated. According to the transition state theory of reaction dynamics, the activation entropy (ΔS), activation Gibbs free energy (ΔG) and equilibrium constant (K ) of the activation state could be calculated. These results permitted thermodynamic analysis of the bacterial growth metabolism.

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Abstract  

A microcalorimetric technique based on the bacterial heat output was applied to evaluate the influence of antibiotics PIP (Piperacillin Sodium) and composite preparation of PIP and SBT (Sulbactam Sodium) on the growth of E. coli DH5α. The power–time curves of the growth metabolism of E. coli DH5α were studied using a TAM Air Isothermal Microcalorimeter at 37C. By analyzing the power–time curves, the parameters such as growth rate constants (k), inhibitory ratio (I), the maximum heat power (P m) and the time of the maximum heat power (t m) were obtained. The results show that different concentrations of antibiotics affect the growth metabolism of E. coli DH5α. The PIP in the concentration range of 0–0.05 g mL–1 has a stimulatory effect on the E. coli DH5α growth, while the PIP of higher concentrations (0.05 –0.25 g mL–1) can inhibit its growth. It seems that the composite preparation composed of PIP and SBT cannot improve the inhibitory effect on E. coli DH5α as compared with the PIP.

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Journal of Thermal Analysis and Calorimetry
Authors: C. Zeng, J.-C. Zhu, Y. Liu, Y. Yang, J.-Y. Zhu, Y.-P. Huang, and P. Shen

Abstract  

Microcalorimetry was used to study the influence of NaCl concentration on Halobacterium salinarum growth. From the thermogenic curves and thermokinetic parameters of H. salinarum growth in different concentrations of NaCl, it was found that the optimum NaCl concentration for H. salinarum growth was not a wide range from 3.5 mol L–1 to NaCl saturation (about 5.2 mol L–1), as is generally acknowledged, but just around 230 g L–1 (approximately 3.9 mol L–1). And when external NaCl concentration was above 230 g L–1, the growth metabolism of H. salinarum decreased constantly with the increasing of NaCl concentration. These have never been described before. Further investigation by transmission electron microscopy revealed that H. salinarum growing in approaching NaCl saturation underwent plasmolysis, which interpreted the novel finding of microcalorimetry perfectly. Our work shows that microcalorimetry may reveal more and newer details about microbial growth than the existing methods do. These details are significant to understand biological processes.

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Niacin (Nicotinic acid, B3 vitamin) may be involved in reduction of toxic effects of boron by regulating growth metabolism. This study was designed to examine whether external niacin treatment would improve the boron mobility in carrot callus cells or not. The results showed that excess boron caused tracheary inversions in meristematic root tissue, and also a shortage was seen in tracheary lengths with boric acid treatment. Boron excess induced the plant tolerance to water stress inverting the tracheary cells. This shortage converted nearly to normal size with niacin and boron treatment together. The results showed that boron mobility induced by niacin could reduce significantly the fresh and dry weight of carrot root cells, protein and ABA content was reduced also, in contrary, external boron and boron with niacin treatment considerable increased the two factors after one month stress. Fresh weight reduction and ABA content reduction indicated that niacin treatment caused water stress on the root cells of carrot, but boron treatment and boron with niacin treatment increased drought tolerance in carrot cells by increasing the both factors. In addition, turning the conversion of the length of the trachearies to their normal size proved that niacin treatment ended the polarizing effects of boron on cell walls.

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Abstract  

In this study, the microcalorimetric method was applied to investigate the activity of berberine on Shigella dysenteriae (S. dysenteriae). Heat flow power (HFP)–time curves of the growth metabolism of S. dysenteriae affected by berberine were determined using the thermal activity monitor (TAM) air isothermal microcalorimeter, ampoule mode, at 37 °C. By analyzing these curves and some quantitative parameters using multivariate analytical methods, similarity analysis (SA) and principal component analysis (PCA), the antibacterial activity of berberine on S. dysenteriae could be accurately evaluated from the change of the two main parameters, the maximum heat flow power P m 2 and total heat output Q t: berberine at low concentration (25 μg mL−1) began to inhibit the growth of S. dysenteriae, high concentrations (50–200 μg mL−1) of berberine had strong antibacterial activity on S. dysenteriae, when the concentration of berberine was higher (250–300 μg mL−1), this antibacterial activity was stronger. All these illustrated that the antibacterial activity of berberine on S. dysenteriae was enhanced with the increase of the concentration of this compound. Berberine can be used as potential novel antibacterial agent for treating multidrug-resistant Shigella. This work provided a useful idea of the combination of microcalorimetry and multivariate analysis for studying the activity of other compounds or drugs on organisms.

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Application of microcalorimetry and chemometric analysis

Effects evaluation of angle and nail animal drugs on Bacillus subtilis growth

Journal of Thermal Analysis and Calorimetry
Authors: Xiaoyan Xing, Yanling Zhao, Weijun Kong, Yanwei Zhong, Dan Yan, Ping Zhang, Yumei Han, Lei Jia, Cheng Jin, and Xiaohe Xiao

Abstract

In this study, microcalorimetry combined with chemometric analysis was used to investigate the effects of angle and nail animal valuable drugs on Bacillus subtilis (B. subtilis) growth. The power–time curves of the growth metabolism of B. subtilis affected by Cornu Cervi Pantotrichum, Cornu Cervi Elaphi, Cornu Saigae Tataricae, cornu caprae hircus, Cornu Bubali, Squama Manis, and Carapax Trionycis were determined using a thermal activity monitor (TAM) air isothermal microcalorimeter, ampoule mode, at 37 °C. By analyzing these curves and some quantitative parameters using principal component analysis, the effects of the seven animal drugs on B. subtilis could be quickly evaluated from the change of the two main parameters, the maximum heat-flow power P m 2 and total heat output Q t: Cornu Saigae Tataricae, cornu caprae hircus, Cornu Bubali, Squama Manis, and Carapax Trionycis inhibited the growth of B. subtilis, while Cornu Cervi Pantotrichum and Cornu Cervi Elaphi promoted the growth of B. subtilis. Further, the result of hierarchical clustering analysis showed that the drugs which promoted the growth of B. subtilis gathered in one cluster, the other drugs which inhibited the growth of B. subtilis gathered in the other cluster. All these illustrated that the internal characteristics of the seven animal drugs were different though they had similar resources and these drugs could be well clustered according the effects of them on B. subtilis growth with the help of chemometric methods. This study provided an useful idea of the combination of microcalorimetry and chemometric analysis for studying the effects of drugs on organisms.

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