PROPHAGE INDUCTION AND FILAMENT FORMATION IN A MUTANT STRAIN OF ESCHERICHIA COLI
PROPHAGE INDUCTION AND FILAMENT FORMATION IN A MUTANT STRAIN OF ESCHERICHIA COLI
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DOI：
10.1073/pnas.58.5.1903
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发表时间：
1967-01-01
影响因子：
11.1
通讯作者：
GOLDTHWAIT, DA
中科院分区：
文献类型：
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作者：
KIRBY, EP;JACOB, F;GOLDTHWAIT, DA
材料与方法。-细菌和噬菌体：大肠杆菌K-12， C-600, thr, leu, thi，溶原菌株x，是本研究中使用的菌株的亲本。用C-600溶原菌株和非溶原菌株作为对照，用热诱导菌株进行实验，热诱导菌株的分离描述如下。AB1899离子，一种大肠杆菌菌株，在低剂量紫外线照射后形成细丝，由P. Howard-Flanders博士获得。Hfr A-235由SE Luria博士获得。培养基和化学试剂：最小培养基M-635中添加0.2%葡萄糖、0.2% Difco酪胺酸（分别添加0.01% l -色氨酸、l -丝氨酸和l -苏氨酸）和0.01%盐酸硫胺素。营养肉汤用每升16克的营养肉汤粉或每升5克的肉精、10克的蛋白胨和5克的NaCl配制，用NaOH调节pH为7.4。Hadacidin由Shigeura博士，Merck， Sharp和Dohme， Rahway， nj提供。生长实验：在室温下培养过夜的培养物被稀释到含有0.2%葡萄糖，0.2%强化酪氨酸，0.01%硫胺素HC1和0.01%鸟苷和胞苷的M-63培养基中。然后将培养物在26-28℃下摇匀，直至进入对数相。它们被迅速冷却和离心，细菌被洗涤并在含有葡萄糖、酪胺酸和硫胺素的冷M-63培养基中重悬。将这些悬浮液的10毫升样品加入含有适当添加剂的125毫升浊度计烧瓶中。然后将培养物在400℃下摇匀，用Klett色度计在660℃下测定培养物的光密度。对紫外线照射的敏感性：细胞在营养肉汤中生长至log期，然后冷却并在冷M-63最小培养基中重悬至一定密度
Materials and Methods.-Bacteria and bacteriophage: Escherichia coli K-12, C-600, thr, leu, thi, lysogenic forX, was the parent of the strains used in this study. The lysogenic and nonlysogenic strains of C-600 were used as controls for experiments with the thermoinducible strain, whose isolation is described below. AB1899 ion, a strain of E. coli which forms filaments after low doses of UV light was obtained from Dr. P. Howard-Flanders. Hfr A-235 was obtained from Dr. SE Luria. Media and chemicals: Minimal medium M-635 was supplemented with 0.2% glucose, 0.2% Difco casamino acids (fortified with 0.01% each L-tryptophan, L-serine, and L-threonine), and 0.01% thiamin hydrochloride. Nutrient broth was prepared with either 16 gm. per liter of Difconutrient broth powder or with 5 gm of meat extract, 10 gm of peptone, and 5 gm of NaCl per liter with the pH adjusted to 7.4 with NaOH. Hadacidin was provided by Dr. Shigeura, Merck, Sharp, and Dohme, Rahway, NJGrowth experiments: Cultures which had been grown overnight at room tempera-ture were diluted into M-63 medium containing 0.2% glucose, 0.2% fortified casamino acids, 0.01% thiamin HC1, and 0.01% guanosine and cytidine. The cultures were thenshaken at 26-28 until in log phase. They were quickly chilled and centrifuged and the bacteria were washed and resuspended in cold M-63 medium containing glucose, casamino acids, and thiamin. Ten-ml samples of these suspensions were added to 125-mlnephelometer flasks containing the appropriate additions. The cultures were then shaken at 400, and the optical density of the cultures was followed at 660 m1Awith a Klett colorimeter. Sensitivity to UV irradiation: Cells were grown in nutrient brothuntil in log phase, then chilled and resuspended in cold M-63 minimal medium'to a density