FIG. 2.

Effect of novobiocin and nalidixic acid on GA-1 DNA replication. Bacillus sp. strain G1R cells were infected with phage GA-1, and 25 min later the culture was divided into three aliquots and further grown in the presence of novobiocin (+Nov) or nalidixic acid (+Nal) (500 μg of each/ml) or with no addition (C). Aliquots were obtained at the indicated times after infection, and the DNA was purified by phenol extraction and ethanol precipitation. The amount of GA-1 DNA was calculated by real-time PCR of the left terminal sequence (L; see Fig. 1A). The data are expressed as nanograms of full-length GA-1 DNA per milliliter of culture.