Here we report the results obtained for a strain isolated from a polluted site and classified as Azospira sp. OGA 24. The capability of OGA 24 to utilize perchlorate and nitrate and the regulation of pathways were investigated by growth kinetic studies and analysis of messenger RNA (mRNA) expression of the genes of perchlorate reductase alpha subunit (pcrA), chlorite dismutase (cld), and periplasmic nitrate reductase large subunit (napA). In aerobic conditions and in a minimal medium containing 10 mM acetate as carbon source, 5.6 ± 0.34 mmol L−1 perchlorate or 9.7 ± 0.22 mmol L−1 nitrate were efficiently reduced during the growth with 10 mM of either perchlorate or nitrate. In anaerobiosis, napA was completely inhibited in the presence of perchlorate as the only electron acceptor, pcrA was barely detectable in nitrate-reducing conditions. The cell growth kinetics were in accordance with expression data, indicating a separation of nitrate and perchlorate respiration pathways. In the presence of both compounds, anaerobic nitrate consumption was reduced to 50% (4.9 ± 0.4 vs. 9.8 ± 0.15 mmol L−1 without perchlorate), while that of perchlorate was not affected (7.2 ± 0.5 vs. 6.9 ± 0.6 mmol L−1 without nitrate). Expression analysis confirmed the negative effect of perchlorate on nitrate respiration. Based on sequence analysis of the considered genes and 16S ribosomal gene (rDNA), the taxonomic position of Azospira sp. OGA 24 in the perchlorate respiring bacteria (PRB) group was further defined by classifying it in the oryzae species. The respiratory characteristics of OGA 24 strain make it very attractive in terms of potential applications in the bioremediation of environments exposed to perchlorate salts.

中文翻译：

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在固氮螺菌介导的呼吸过程中优先使用高氯酸盐而不是硝酸盐。OGA24

在这里，我们报告了从污染地点分离并归类为 Azospira sp 的菌株获得的结果。OGA 24. 通过生长动力学研究和高氯酸还原酶 α 亚基 (pcrA)、亚氯酸歧化酶 (cld) 基因的信使 RNA (mRNA) 表达分析，研究了 OGA 24 利用高氯酸盐和硝酸盐的能力以及途径的调节和周质硝酸还原酶大亚基 (napA)。在有氧条件和含有 10 mM 醋酸盐作为碳源的基本培养基中，5.6 ± 0.34 mmol L-1 高氯酸盐或 9.7 ± 0.22 mmol L-1 硝酸盐在生长过程中用 10 mM 高氯酸盐或硝酸盐有效减少。在厌氧环境中，在高氯酸盐作为唯一电子受体存在的情况下，napa 被完全抑制，而在硝酸盐还原条件下几乎检测不到 pcrA。细胞生长动力学与表达数据一致，表明硝酸盐和高氯酸盐呼吸途径的分离。在这两种化合物的存在下，厌氧硝酸盐的消耗量降低到 50%（4.9 ± 0.4 与 9.8 ± 0.15 mmol L-1 无高氯酸盐），而高氯酸盐的消耗量不受影响（7.2 ± 0.5 与 6.9 ± 0.6 mmol L -1 不含硝酸盐）。表达分析证实了高氯酸盐对硝酸盐呼吸的负面影响。基于所考虑的基因和 16S 核糖体基因 (rDNA) 的序列分析，Azospira sp. 的分类位置。高氯酸盐呼吸菌 (PRB) 组中的 OGA 24 通过将其分类为米科物种来进一步定义。