Transformation of inorganic and organic arsenic by Alkaliphilus oremlandii sp nov strain OhILAs
Transformation of inorganic and organic arsenic by Alkaliphilus oremlandii sp nov strain OhILAs
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DOI：
10.1196/annals.1419.006
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发表时间：
2008-01-01
期刊：
影响因子：
--
通讯作者：
Stolz, John F.
中科院分区：
文献类型：
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作者：
Fisher, Edward;Dawson, Asia M.;Stolz, John F.
oremlandii Alkaliphilus sp. 11 .菌株OhILAs是中温性的，孢子形成，运动，低摩尔%GC革兰氏阳性。它是从俄亥俄河沉积物中提取的，在含有20毫米乳酸和5毫米砷酸盐的基础培养基上富集，并通过增加砷浓度（10和20毫米）的培养基传代、酸化和连续稀释来分离。最适宜生长的pH值为8.4,16S rRNA基因序列分析表明，该菌株与Alkaliphilus属植物亲缘关系最密切（A. crotonoxidans 95%， A. auruminator 95%， A. metalliredigens 94%）。作为一种严格的厌氧菌，它可以通过丙烯酸酯途径发酵乳酸以及果糖和甘油。A. oremlandii也具有呼吸能力，因为它能够以乙酸盐、丙酮酸盐、甲酸盐、乳酸盐、富马酸盐、甘油或果糖作为电子供体，以砷酸盐和硫代硫酸盐作为终端电子受体。通过生物化学和Western blot分析鉴定了一种组成性表达的呼吸性砷酸盐还原酶，并通过对编码结构亚基arrA的基因的克隆和测序进行了证实。整个arr操纵子以及ars操纵子也在完全注释的基因组中被鉴定出来。A. oremlandii还转化有机砷3-硝基-4-羟基苯胂酸（roxarsone）。生长实验和基因组分析表明，它以异化的方式将有机砷的硝基还原与乳酸或果糖的氧化结合起来，通过钠依赖性ATP合成酶产生ATP。
Alkaliphilus oremlandii sp. nov. strain OhILAs is a mesophilic, spore-forming, motile, low mole%GC gram positive. It was enriched from Ohio River sediments on a basal medium with 20 mM lactate and 5 mM arsenate and isolated through passage on medium with increased arsenic concentration (10 and 20mM), tindalization, and serial dilution. The pH optimal for growth was 8.4 and 16S rRNA gene sequence analysis indicated it is most closely related to species in the genus Alkaliphilus (A. crotonoxidans 95%, A. auruminator 95%, A. metalliredigens, 94%). A strict anaerobe, it can ferment lactate via the acrylate pathway as well as fructose and glycerol. A. oremlandii also has respiratory capability, as it is able to use arsenate and thiosulfate as terminal electron acceptors with acetate, pyruvate, formate, lactate, fumarate, glycerol, or fructose as the electron donor. A respiratory arsenate reductase, which is constitutively expressed, has been identified through biochemical and Western blot analyses and confirmed by cloning and sequencing of the gene encoding the structural subunit arrA. The entire arr operon as well as the ars operon have also been identified in the fully annotated genome. A. oremlandii also transforms the organoarsenical 3-nitro-4-hydroxy benzene arsonic acid (roxarsone). Growth experiments and genomic analysis suggest that it couples the reduction of the nitro group of the organoarsenical to the oxidation of either lactate or fructose in a dissimilatory manner, generating ATP via a sodium dependent ATP synthase.