Bonilla José Oscar, Callegari Eduardo Alberto, Delfini Claudio Daniel, Estevez María Cristina, Villegas Liliana Beatriz
Instituto de Quimica San Luis (INQUISAL) CONICET, San Luis, Argentina.
Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, San Luis, Argentina.
J Basic Microbiol. 2016 Nov;56(11):1212-1221. doi: 10.1002/jobm.201600170. Epub 2016 Jun 10.
The purpose of this study was to investigate the influence of increasing sulfate concentrations on chromium removal, to evaluate the effect of the presence of Cr(VI) on sulfate removal by Streptomyces sp. MC1 and to analyze the differential protein expression profile in the presence of this metal for the identification of proteins repressed or overexpressed. In the presence of Cr(VI) but in the absence of sulfate ions, bacterial growth was negligible, showing the Cr(VI) toxicity for this bacterium. However, the sulfate presence stimulated bacterium growth and Cr(VI) removal, regardless of its concentrations. Streptomyces sp. MC1 showed ability to remove chromium and sulfate simultaneously. Also, the sulfate presence favored the decrease of total chromium concentration from supernatants reaching a decrease of 50% at 48 h. In presence of chromium, seven proteins were down-expressed and showed homology to proteins involved in protein biosynthesis, energy production and free radicals detoxification while two proteins involved in oxidation-reduction processes identified as dihydrolipoamide dehydrogenase and S-adenosyl-l-methionine synthase were overexpressed.
本研究的目的是调查增加硫酸盐浓度对铬去除的影响，评估六价铬的存在对链霉菌MC1去除硫酸盐的影响，并分析在这种金属存在下的差异蛋白质表达谱，以鉴定被抑制或过表达的蛋白质。在有六价铬但没有硫酸根离子的情况下，细菌生长可以忽略不计，这表明六价铬对这种细菌具有毒性。然而，无论硫酸盐浓度如何，其存在都能刺激细菌生长和六价铬的去除。链霉菌MC1显示出同时去除铬和硫酸盐的能力。此外，硫酸盐的存在有利于上清液中总铬浓度的降低，在48小时时降低了50%。在有铬的情况下，7种蛋白质表达下调，与参与蛋白质生物合成、能量产生和自由基解毒的蛋白质具有同源性，而两种参与氧化还原过程的蛋白质（被鉴定为二氢硫辛酰胺脱氢酶和S-腺苷-L-甲硫氨酸合酶）表达上调。
