ISOLATION, CULTURAL MAINTENANCE, AND TAXONOMY OF A SHEATH-FORMING STRAIN OF LEPTOTHRIX-DISCOPHORA AND CHARACTERIZATION OF MANGANESE-OXIDIZING ACTIVITY ASSOCIATED WITH THE SHEATH
ISOLATION, CULTURAL MAINTENANCE, AND TAXONOMY OF A SHEATH-FORMING STRAIN OF LEPTOTHRIX-DISCOPHORA AND CHARACTERIZATION OF MANGANESE-OXIDIZING ACTIVITY ASSOCIATED WITH THE SHEATH
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DOI：
10.1128/aem.58.12.4001-4010.1992
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发表时间：
1992-12-01
影响因子：
4.4
通讯作者：
GHIORSE, WC
中科院分区：
文献类型：
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作者：
EMERSON, D;GHIORSE, WC
从人工铁渗漏出库中分离到一株盘状细毛藻SP-6。它在矿物盐-维生素-丙酮酸介质中缓慢生长，在20-25℃的最低通气量下保持其成鞘表型。从SP-6在充气条件下快速生长后出现在平板上的光滑菌落中分离到一株无鞘变异体SP-6(Sl)。SP-6和SP-6(S1)与以前研究的无鞘菌株SS-1(ATCC 43182)有密切的亲缘关系，但并不完全相同。增加SP-6生长介质中的Mn2+浓度，增加了鞘中的相密度，表明鞘中的氧化锰沉积增加。没有添加Mn2+的培养物的电子显微镜显示，鞘由一层清晰的内层组成，厚度为30-100 nm，外囊层弥漫，厚度可变。通过特征超微结构、电子密度和X射线色散能谱对鞘中的锰氧化物进行了鉴定。在结皮较重的鞘中，锰的氧化物均匀分布在鞘的两层。有鞘细胞比无鞘细胞在用蒸馏去离子水清洗后保留了更多的锰氧化活性，经EDTA-溶菌酶-去污剂处理后，鞘保持了部分活性。与先前报道的SS-1相比，超滤-透析法显著提高了SP-6废液中活性的恢复(L.F.Adams和W.C.Ghiorse，J.细菌素。169：1279-1285,1987)。在SP-6和SP-6(S1)的浓缩废液中鉴定出一个108 kDa的锰氧化蛋白，其活性在洗涤剂中表现出与SS-1相当的稳定性，热失活和化学抑制模式与SS-1相似。
Leptothrix discophora SP-6 was isolated from the outflow reservoir of an artificial iron seep. Its sheath-forming phenotype was maintained by slow growth in a mineral salts-vitamin-pyruvate medium under minimal aeration at 20 to 25-degrees-C. A sheathless variant, SP-6(sl), was isolated from smooth colonies that appeared on spread plates after rapid growth of SP-6 in well-aerated cultures. SP-6 and SP-6(sl) are closely related but not identical to the previously studied sheathless strain SS-1 (ATCC 43182). Increasing Mn2+ concentrations in the growth medium of SP-6 increased the phase density of the sheath, indicating increased Mn oxide deposition in the sheath. Electron microscopy of cultures grown without added Mn2+ revealed that the sheath consisted of a well-defined inner layer, 30 to 100 nm thick, and a diffuse outer capsular layer of variable thickness. Mn oxides were identified in the sheath by their characteristic ultrastructure, electron density, and X-ray-dispersive energy spectra. In heavily encrusted sheaths, the Mn oxides were evenly distributed in both layers of the sheath. Sheathed cells retained more Mn-oxidizing activity than did sheathless cells after washing with distilled, deionized water, the sheath retained some of its activity after an EDTA-lysozyme-detergent treatment which removed the cells. An ultrafiltration-dialysis procedure significantly increased the recovery of activity from spent media of SP-6 over that reported previously for SS-1 (L. F. Adams and W. C. Ghiorse, J. Bacteriol. 169:1279-1285, 1987). A 108-kDa Mn-oxidizing protein was identified in concentrated spent media of SP-6 and SP-6(sl), and the activity of the concentrates showed stability in detergents comparable to that of SS-1 and patterns of heat inactivation and chemical inhibition similar to those of SS-1.