趋磁细菌研究 Ⅳ.好氧趋磁细菌HM-1的分离及生物学特性研究

ISOLATION OF A AEROBIC MAGNETOTACTIC BACTERIUM HM 1 AND STUDIES ON ITS BIOLOGICAL CHARACTERSTICS

从黄石磁湖底部泥水样中分离到一株杆状好氧趋磁细菌ＨＭ－１，在ｐＨ７．０～８．０、３０℃振荡培养的条件下培养时，每升培养基含４ｇ柠檬酸，０．５ｇ硝酸钠和５０ｍｍｏｌ·Ｌ－１ＦｅＳＯ４，分别是它生长和磁小体合成的最适碳源、氮源和铁源；此菌为Ｇ－，氧化酶和过氧化物酶阳性，不积累聚－β－羟丁酸，Ｇ＋Ｃ的摩尔分数为６４．０８（ＨＰＬＣ）；磁小体含一种矿质元素Ｆｅ．

A rod shaped magnetic bacterium was isolated from freshwater sediment and a pure culture was obtained. The organism was cultured in a chemical defind medium containing citric acid (4 g·L -1 ), nitrate (0 5 g·L -1 ) and FeSO 4 (50 mmol·L -1 ) as the carbon, nitrogen and iron soures respectivelly. This magnetotactic bacterium was G - and able to form white colonies on ager plate and grow in O 2 contained atmosphere (shaked at 200 r·min -1 ). In this condition, it synthsised magnetosomes, showed catalase and oxidase activities. Microaerophili condition was influeuce for its growth and magnetosomes formation. Intracellalar poly β hydroxybutyrate is not formed. The X G+C of the DNA is 64.08 (HPLC). The entrgy profiles of X ray showed by electron excitation in TEM indicating that its magnetosome consists of one mineral element Fe only.