Wang Fei, Yao Jun, Chen Huilun, Zhou Yong, Chen Yanjiao, Chen Haiyan, Gai Nan, Zhuang Rensheng, Tian Lin, Maskow Thomas, Ceccanti Brunello, Trebse Polonca, Zaray Gyula
School of Environmental Studies and Key Laboratory of Biogeology and Environmental Geology of Chinese Ministry of Education and Sino-Hungarian Joint Laboratory of Environmental Science and Health, China University of Geosciences, 430074 Wuhan, PR China.
School of Environmental Studies and Key Laboratory of Biogeology and Environmental Geology of Chinese Ministry of Education and Sino-Hungarian Joint Laboratory of Environmental Science and Health, China University of Geosciences, 430074 Wuhan, PR China.
Ecotoxicol Environ Saf. 2009 Jan;72(1):128-135. doi: 10.1016/j.ecoenv.2008.01.012. Epub 2008 Mar 6.
A microcalorimetric technique was applied to a series of experiments to follow the toxic effect caused by the trivalent iron on the single and mixed microbes in sterilized soil that was inoculated with the single Bacillus subtilis (B. subtilis) (prokaryotic bacterium), single Candida humicola (C. humicola) (eukaryotic fungus) and the mixed-species. The microbial activity was stimulated by the addition of 5.0mg glucose and 5.0mg ammonium sulfate under a 35% controlled humidity in the studied soil samples of 1.2g. The power-time curves from every experiment were analyzed, and from these analyses characteristic parameters, such as growth rate constant (k) and total thermal effect (Q) which can reflect the biochemical reactions were determined. The mixed-species have moderate tolerance to the iron overload, comparing with single species, and exhibit synergistic interaction in exponential growth phase (0-400.0 microg mL(-1)). Meanwhile, there is no much difference in the thermal effect (Q) per gram soil sample for the single and mixed culture. This also validates that the nutrient substances in natural environment determine the organisms' metabolic activities. Ultraviolet-visible spectrophotometry and dissolved oxygen sensor also were successfully applied to reflect the activities of B. subtilis and C. humicola in the pure culture. The investigation could provide insight into the microbial ecology of bacteria and fungi in ecological niches.
采用微量量热技术进行了一系列实验，以追踪三价铁对灭菌土壤中单一和混合微生物的毒性作用，该土壤接种了单一的枯草芽孢杆菌（原核细菌）、单一的土生假丝酵母（真核真菌）以及混合菌种。在1.2克被研究土壤样品中，通过添加5.0毫克葡萄糖和5.0毫克硫酸铵，在35%的控制湿度下刺激微生物活性。分析了每个实验的功率-时间曲线，并从这些分析中确定了能够反映生化反应的特征参数，如生长速率常数（k）和总热效应（Q）。与单一菌种相比，混合菌种对铁过载具有中等耐受性，并且在指数生长期（0 - 400.0微克/毫升）表现出协同相互作用。同时，单一培养和混合培养的每克土壤样品的热效应（Q）没有太大差异。这也证实了自然环境中的营养物质决定了生物体的代谢活动。紫外可见分光光度法和溶解氧传感器也成功用于反映纯培养中枯草芽孢杆菌和土生假丝酵母的活性。该研究可以深入了解生态位中细菌和真菌的微生物生态学。
