title: Rapid inactivation of bacteriophage T7 by ascorbic acid is repairable.
abstract: Treatment of bacteriophage T7 with ascorbic acid resulted in the rapid accumulation of single-strand breaks in the DNA with double-strand breaks appearing only after incubation times of 20 min or longer. The single-strand breaks were responsible for a rapid inactivation of the phage as assayed by immediate plating of the phage-bacteria mixture on nutrient agar. Incubation of the phage-bacteria mixture in liquid medium prior to plating allowed a host cell reactivation process to repair the nicks and reactivate the phage. Non-reversible inactivation of the phage was a slower process which could be correlated with the appearance of double-strand breaks in the phage DNA. Host cell reactivation of the phage was also manifested in the phenomena of delayed lysis and delayed appearance of the concatemeric DNA replication intermediate.
mesh_terms: D001205:Ascorbic Acid / Q000494:pharmacology*; D003090:Coliphages / Q000187:drug effects / Q000235:genetics*; D004260:DNA Repair; D004261:DNA Replication / Q000187:drug effects; D004277:DNA, Single-Stranded / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics*; D007700:Kinetics; D013045:Species Specificity; D014779:Virus Replication / Q000187:drug effects
chemical_list: D004277:DNA, Single-Stranded; D004279:DNA, Viral; D001205:Ascorbic Acid