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Colla corii asini (CCA) is a widely used animal-derived traditional medicine and nutritional supplement in China that has a variety of bioactive effects, especially anti-anaemic effects. To date, the effective substances in CCA are still unclear, thus limiting the evaluation of the quality and consistency of CCA. In this study, a microcalorimetry-based bioassay method was established to assess the quality of CCA by investigating its effects on the growth and metabolism of Escherichia coli, and ten biothermodynamic parameters were employed to characterize the biothermal changes. A principal component analysis (PCA) of these parameters showed that CCA significantly promotes the heat production of E. coli compared to that in the control group, and CCA showed an obvious dose–effect relationship from 0.625 to 20 mg mL−1. Then, the effects of 12 batches of CCA from three different manufacturers were studied at a concentration of 5 mg mL−1, which had a good effect and showed good intraday and daytime reproducibility. The results revealed distinctive characteristics among different manufacturers and good consistency within the same manufacturer according to the scores of the first principal component. In summary, the method based on microcalorimetric has good prospects in the evaluation of the quality of CCA. [ABSTRACT FROM AUTHOR]

Microcalorimetric techniques had been used to study the influence of different physicochemical parameters on microbial growth in different permafrosts on the Tibetan plateau. The total heat evolution of the permafrost samples amended with glucose, Q, the values of microbial growth rate constant, k, and the heat output power, P, were calculated from the power-time ( P- t) curves. It is observed that the same coverage vegetation show similar P- t curves, which strongly suggest that the permafrost microorganisms of the homology vegetation coverage have similar structures of community. Furthermore, the vegetation degradation turns out to have significant influence, that is, the better the status of vegetation is, the higher the values of k, CFU and Q are. [ABSTRACT FROM AUTHOR]

Currently there are very few researches on studying the vertical changes of metabolic and thermodynamic properties of microbial communities in freshwater lake sediment. In this work, a multi-channel microcalorimetric system was applied to investigate both the metabolism and thermodynamic properties of 0-35 cm sediment cores from Lake Honghu (Jingzhou, Hubei Province, China). It is suggested that the catastrophic flood in 1998 had changed the structure of the 20-25 cm sediment layer. In this layer, both the physicochemical properties of sediment and the thermodynamic activities of microorganisms exhibit distinct differences from other layers. It displays the highest TOC, TN and C/N values. The power-time curves of microcalorimetric measurement on the sediment samples were plotted to illustrate their microbial activities. The 20-25 cm sediment layer showed the lowest microbial activities with a maximum heat flow rate of 56.97 μW, a growth rate constant of 0.06 h-1 and the time to reach the peak was 98 h. A positive correlation (r= 0.972, P< 0.001) was found between the cell specific metabolic enthalpy change rate (ΔH0) and the TOC of the sediment samples. ΔH0 could indicate the utilization efficiency of carbon source which is not affected by the biomass but relies on the intrinsic properties of sediment. Our work shows that the higher the TOC in sediment; the lower the efficiency in assimilating carbon into biomass by the microbes. [ABSTRACT FROM AUTHOR]

Microcalorimetry, plate count and PCR–denaturing gradient gel electrophoresis (DGGE) were employed to investigate microbial diversity and activity in soils from the Red Soil Experimental Station of the Chinese Academy of Agricultural Sciences, Hunan Province, China, where a wheat–corn rotation with 12 fertilization treatments was established in 1990. Fertilization greatly increased microbial biomass carbon (C) and nitrogen (N) (Cmic and Nmic) as well as the activities of phosphatase, urease, invertase, protease, catalase and dehydrogenase. Manure alone (M) enhanced the number of denitrifying and aerobic bacteria by 54.4% and 20.5%, respectively, whereas fallow (H) increased the number of aerobic cellulose decomposing bacteria by 31.4%. Fallow and soils amended with mineral fertilizers plus pig manure or straw increased both the DGGE band patterns and the Shannon index compared with mineral fertilizers or the control. Mineral treatments with lower bacterial numbers enhanced the values of the peak time ( tmax) more than did organic treatments. The peak height ( Pmax) was positively correlated ( P<0.01), with soil enzymes, Cmic and Nmic, and the number of microorganisms, whereas the peak time ( tmax) was negatively connected ( P<0.01) with these parameters. The microbial growth rate constant ( k) was linked to bacteria ( P<0.01), actinomycetes ( P<0.05) and catalase ( P<0.05). The total heat evolution ( Q) had no relationships with any soil microbial properties (except for catalase). We propose that Pmax and tmax could be used as indices of soil microbial activity, while the values of k and Q are poor indicators. [ABSTRACT FROM AUTHOR]

A pure culture using aniline as a sole source of carbon and energy was isolated by selective enrichment culturing on a minimum salt medium (MSM) from the Nanjing Chemical Plant, Nanjing, Jiangsu Province, China. An analysis of the 16S rRNA gene sequence and morphological and physiological characteristics showed that this strain was a member of the genus Rhodococcus, and it was designated as strain AN5. Its optimal conditions for aniline biodegradation were 30°C (pH 7.0). Due to the water insolubility of aniline, growth of strain AN5 at various aniline concentrations was studied via spectrophotometry and microcalorimetry in different culture mediums. Strain AN5 not only utilized aniline as its sole carbon and energy resources, but also degraded phenol, benzoic acid and naphthalin. Glucose, peptone and ammonium sulfate, when utilized as its secondary carbon and nitrogen sources, had no active effect on the aniline biodegradation. Such findings would be valuable in the application of strain AN5 to depurate industrial waste water. [ABSTRACT FROM AUTHOR]

Contamination with oil poses a threat to the environment and to human health worldwide. Biological methodologies have proved to be economical, versatile and efficient for the remediation of pollutants. In this paper, a highly efficient oil-degrading bacterial strain USTB-2 was isolated from an oil production well of Dagang oil field in Tianjin, China. The 16S rRNA sequence of USTB-2 showed 100% similarity with that of Bacillus subtilis BSn5. Hexadecane is one of the most important components in petroleum. The half inhibitory ratio (IC₅₀) of hexadecane inhibited organisms, determined by microcalorimetry, was lower in USTB-2 than in B. BSn5. The results indicate that the strain USTB-2 degrades hexadecane to make it less toxic compared with the normal strain. RT-PCR was used to evaluate the expression of oil-degrading enzymes, specifically 4-hydroxyphenylacetate 3-monooxygenase genes (HPMO). A sharp increase in the expression of HPMO genes was observed for USTB-2, while the expression of HPMO genes in reference strain B. BSn5 remained relatively stable. These methods can be used to study the metabolic potential of microorganisms for in situ oil decontamination., (Copyright © 2013 Elsevier Ltd. All rights reserved.)