ISOLATION AND PURE CULTURE OF A FRESHWATER MAGNETIC SPIRILLUM IN CHEMICALLY DEFINED MEDIUM
ISOLATION AND PURE CULTURE OF A FRESHWATER MAGNETIC SPIRILLUM IN CHEMICALLY DEFINED MEDIUM
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DOI：
10.1128/jb.140.2.720-729.1979
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发表时间：
1979-01-01
影响因子：
3.2
通讯作者：
WOLFE, RS
中科院分区：
文献类型：
--
作者：
BLAKEMORE, RP;MARATEA, D;WOLFE, RS
通过对淡水沼泽沉积物施加磁场，分离出一种含有单畴大小的磁铁矿晶体细胞内链的双极鞭毛趋磁菌。将该生物体培养在含有奎尼酸铁和琥珀酸盐分别作为Fe和C源的化学成分确定的培养基中。该分离物的非磁性变体保持在缺乏奎尼酸铁的化学成分确定的培养基中。与磁性细胞相比，这些细胞的铁含量较少，缺乏可测量的剩磁和胞质内晶体。在G + C摩尔百分含量、生长特性、营养生理等方面，两种类型的小麦基本相似。该菌株在生长过程中还原硝酸盐，不积累亚硝酸盐，并产生NO3-。NH_3或NH_4 ~+为氮源。该微生物是微需氧的，在培养基中含硝酸盐时不会厌氧生长。在化学成分确定的培养基中，细胞合成磁铁矿，只有当密封培养物的气氛中的初始O2浓度为6%（体积/体积）或更低。
A bipolarly flagellated magnetotactic spirillum containing intracellular chains of single domain-sized magnetite crystals was isolated by applying a magnetic field to sediments from a freshwater swamp. The organism was cultured in a chemically defined medium containing ferric quinate and succinate as sources of Fe and C, respectively. Non-magnetic variants of this isolate were maintained in chemically defined medium lacking ferric quinate. In contrast to magnetic cells, these had less Fe and lacked measurable magnetic remanence and the intracytoplasmic crystals. In other respects, including moles percent G + C content, growth characteristics, nutrition and physiology, the 2 types were similar. The isolate reduced nitrate without accumulating nitrite and produced NO3- during growth. NH3 or NH4+ served as a N source. The organism was microaerophilic and did not grow anaerobically with nitrate in the medium. In chemically defined medium, cells synthesized magnetite only if the initial O2 concentration in the atmosphere of sealed cultures was 6% (vol/vol) or less.