PRICE K E, BUCK R E, LEIN J
Appl Microbiol. 1964 Sep;12(5):428-35. doi: 10.1128/am.12.5.428-435.1964.
Studies were conducted to determine conditions of maximal sensitivity for a test system designed to detect chemical inducers of phage production in the streptomycin-dependent, lysogenic Escherichia coli strain W1709(lambda). This strain was found to be induced by all antibiotics previously reported to be inducers of E. coli K-12(lambda). However, the system employing W1709(lambda) proved superior for screening fermentation filtrates because its growth, in contrast to that of K-12(lambda), was not stimulated during the induction period by filtrate nutrients. Thus, misleading high phage counts, which accompany cell growth stimulation, were not produced by filtrates devoid of inducing activity. The inducing capability of 95 fermentation filtrates, each containing an unidentified antibiotic(s) inhibitory for one or more transplanted rodent tumors, was determined in the W1709(lambda) system. A low incidence of inducers was found among inhibitors of sarcoma 180, adenocarcinoma 755, solid myeloid leukemia C1498, and adenocarcinoma of the duodenum in the hamster. However, seven of eight filtrates active against leukemia 1210 had induction capability. From a screen of actinomycete culture filtrates, 28 of the first 1,000 were identified as producers of induction activity. Thus far, of the nine cultures from this group that were subjected to examination, eight demonstrated at least presumptive evidence of antineoplastic activity.
开展了多项研究，以确定用于检测链霉素依赖型溶原性大肠杆菌菌株W1709(λ)中噬菌体产生化学诱导剂的测试系统的最大灵敏度条件。已发现该菌株可被先前报道的所有诱导大肠杆菌K-12(λ)的抗生素诱导。然而，采用W1709(λ)的系统在筛选发酵滤液方面被证明更具优势，因为与K-12(λ)相比，其生长在诱导期不会受到滤液营养物质的刺激。因此，缺乏诱导活性的滤液不会产生伴随细胞生长刺激的误导性高噬菌体计数。在W1709(λ)系统中测定了95种发酵滤液的诱导能力，每种滤液都含有一种或多种对一种或多种移植性啮齿动物肿瘤有抑制作用的未鉴定抗生素。在仓鼠肉瘤180、腺癌755、实体髓性白血病C1498和十二指肠腺癌的抑制剂中，诱导剂的发生率较低。然而，对白血病1210有活性的八种滤液中有七种具有诱导能力。从放线菌培养滤液的筛选中，前1000种中有28种被鉴定为诱导活性产生菌。到目前为止，在对该组中的九种培养物进行检查时，有八种至少显示出抗肿瘤活性的初步证据。
