. The actinomycetes. Actinomycetales. 180 THE ACTINOMYCETES, Vol. I. Figure 77. Phage particles adsorbed on a streptomyces spore (Reproduced from: Mach, F. Centr. Bakteriol. Parasitenk. Abt. II; 111: 556, 1958). ophage in greenhouse soils. In four out of fourteen samples of soil, free actinophages were revealed by direct count. In most cases these actinophages proved to be polyvalent. In another ten samples of greenhouse soils and in twenty-five samples of forest and meadow soils, as well as in filtrates of field soils, no free actinophage Avas found. Many actinomycetes isolated from these soi
. The actinomycetes. Actinomycetales. 180 THE ACTINOMYCETES, Vol. I. Figure 77. Phage particles adsorbed on a streptomyces spore (Reproduced from: Mach, F. Centr. Bakteriol. Parasitenk. Abt. II; 111: 556, 1958). ophage in greenhouse soils. In four out of fourteen samples of soil, free actinophages were revealed by direct count. In most cases these actinophages proved to be polyvalent. In another ten samples of greenhouse soils and in twenty-five samples of forest and meadow soils, as well as in filtrates of field soils, no free actinophage Avas found. Many actinomycetes isolated from these soils were susceptible to the eight different actino- phages previously isolated. Mach (1958) iso- lated from composts and forest litter three actinophages of which two were polyvalent and one strongly specific. These three phages were morphologically distinct from one an- other, as shown by the electron microscope. Bradley and Anderson (1958) isolated from soil three streptomyces phages and five nocardia phages. Of the former, one attacked a culture designated as A'", paraguayensis, and of the latter, three attacked streptomyces. All other Actinomycetales were resistant to both types of phage, as shown in Table 45. On the basis of these results, the authors con- cluded that the genera Nocardia and Strepto- myces are closely related and should not be separated into different families. Such gen- eralization is hardly justified. The A^. para- guayensis used in these tests is not a no- cardia, but a streptomyces, as will be brought out in Vol. II. The nocardia phages that attacked the streptomyces cultures may have been polyvalent phages, a potentiality indicated in the early studies of Wieringa andWeibols (19o(i). The sensitivity to phages. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Waksman, Selman A. (
Size: 1669px × 1497px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcoll, bookpublisherbaltimorewilliamswilkins
