[Fungal origin of PBV-group viruses isolated from Penicillium brevi-compactum].

Treatment of extracts from the disintegrated mycelium of Penicillium brevi-compactum with antisera against viruses PBV-1 and PBV-3 grown on bacteria results in a considerable decrease in the infectiveness of micellar preparations toward E. coli C. This is a specific reaction since treatment with a heterologic antiserum against phage T2 has no effect on the infectiveness of the micellar extracts. The kinetics of reassociation of DNA from PBV-3 and DNA from Penicillium brevi-compactum has shown that the value of Cot at half-reassociation of these DNAs is 13.3 times higher than the value of Cot at half-reassociation of DNA from PBV-3 and heterologic DNA from chicken embryos. As was found by calculations, DNA isolated from the fungal mycelium contains virus sequences at an amount of 3.7 virus genomes per cell. These data confirm the micellar origin of the viruses PBV-1 and PBV-3. The virus PBV-3 is supposed to be present in the cells in the form of prophage.