Waite Carolina Coelho da Costa, da Silva Guilherme Oliveira Andrade, Bitencourt José Augusto Pires, Sabadini-Santos Elisamara, Crapez Mirian Araújo Carlos
Programa de Biologia Marinha e Ambientes Costeiros, Instituto de Biologia, Universidade Federal Fluminense, Niterói, RJ 24020-150, Brazil.
Programa Dinâmica dos Oceanos e da Terra, Instituto de Geociências, Universidade Federal Fluminense, Niterói, RJ 24210-346, Brazil.
Mar Pollut Bull. 2016 Aug 15;109(1):386-392. doi: 10.1016/j.marpolbul.2016.05.044. Epub 2016 May 25.
A bacterial consortium was selected in the presence of Cu from sediment samples taken from Sepetiba Bay, Brazil, which is a site historically contaminated by metals. Bacteria were exposed to 0, 1, 6, 12.5, 25 and 50μg·mL(-1) Cu, Pb and Cu+Pb for 11days of bioassay. Results showed Alcanivorax dominance (81%) and cell counts of 10(8)cells·mL(-1). However, a reduction in dehydrogenase activity was observed from the fifth day of exposure for all Cu, Pb, and Cu+Pb concentrations tested. Esterase activity tended to increase, indicating higher energy demand to complete the bacterial lifecycle. Pb concentrations in the filtered culture medium (0.2μm) were below the detection limit, indicating biosorption, whereas concentrations of Cu were close to the tested concentrations, indicative of efflux. Results suggest the need for biomarkers, such as esterase and dehydrogenase enzymatic activity, in the assessment of resistance and tolerance of communities previously exposed to stressors.
从巴西塞佩蒂巴湾采集的沉积物样本中，在铜存在的情况下选择了一个细菌群落，该海湾是一个历史上受金属污染的地点。将细菌暴露于0、1、6、12.5、25和50μg·mL(-1)的铜、铅以及铜 + 铅中，进行为期11天的生物测定。结果显示食烷菌占主导地位（81%），细胞计数为10(8)个细胞·mL(-1)。然而，在所有测试的铜、铅以及铜 + 铅浓度下，从暴露的第五天开始观察到脱氢酶活性降低。酯酶活性趋于增加，表明完成细菌生命周期需要更高的能量需求。过滤后的培养基（0.2μm）中的铅浓度低于检测限，表明存在生物吸附，而铜的浓度接近测试浓度，表明存在外排。结果表明，在评估先前暴露于应激源的群落的抗性和耐受性时，需要诸如酯酶和脱氢酶酶活性等生物标志物。
