嗜盐杆菌属—新种

A NEW SPECIES OF HALOBACTERIUM

从西藏扎北湖石盐样品中分离到数株嗜盐菌,其中521菌株在15—25%浓度 NaCl 的培养基上生长,最适 NaCl 浓度为20%,低于10%或饱和 NaCl 培养基中不生长。细胞壁不含二氨基庚二酸,细胞膜含有甘油二醚键的不皂化性磷酸甘油醚衍生物,产色素。革兰氏阴性杆菌,细胞单个存在,大小为0.6—0.8×1.5—2.5μm。在牛奶-盐-琼脂培养基上菌落呈橙红色,圆形,边缘整齐,表面光滑湿润,直径1mm。专性好氧菌,最适生长温度37℃,不由色氨酸产生吲哚,不产生 H_2S,不还原硝酸盐,能利用葡萄糖等多种糖,并以葡萄糖产酸。具有过氧化氢酶和氧化酶。DNA 中 G+c 为62.7mol%(Tm)。经鉴定,521菌株为嗜盐杆菌属的一个新种,命名为扎北盐杆菌(Halobacterium zhabeiensis sp.nov.)。

Strain 521 and several other strains ofhalobacteria with rodshaped cells are isolatedfrom salt samples of Zhabei Lake in Tibet.The optimum salt concentration for its growthis 20% NaCl;no appreciable growth is foundbelow 10% NaCl and in the NaCl mediumsaturated.Its cell wall does not containdiaminopimelic acid,and most of the celllipids are nonsaponifiable phosphoglycollipidderivatives,in which glycol-diethers is detect-ed.The strain produces pigments.Strain 521 is non-motil,Gram-negativerods,with the size of single cell of 0.6—0.8by 1.5—2.5 μm.The colony on milk-salt-agar is round,entire,smooth,moist,glisten-ing,orange red in colour and 1 mm in dia-meter.The optimum growing temperature is37℃.It is obligate aerobes.It does notproduce indole,H_2S and it produces nitritefrom nitrate medium.Ribose and fructoseare not utilized.But glocose,glycerol and soon,are utilized,and it produces acid fromglucose.Strain 521 possesses oxidase andcatalase.The G+C mol% of DNA is 62.7(Tm).Therefore,strain 521 is consideredas one new species and it is namedHalobacterium zhabeiensis sp.nov.