Abstract
Multiplication characteristics of FRNA phage was studied. Using FRNA phage Qβ and Escherichia coli K12 A/λ (F+), concentration of host bacteria and FRNA phages in constant temperature incubation was measured after certain time intervals. FRNA phage inoculated in host culture growing exponentially multiplied while inoculated in host culture in steady state phase didn't multiply. Higher yield of FRNA phage was obtained when incubated in higher substrate concentration. Incubation temperature greatly affected FRNA phage multiplication. In 35°C and 30°C condition FRNA phage multiplied. But decrease of the incubation temperature resulted in decrease of FRNA phage production and finally in 25°C condition FRNA phage didn't multiply. On the other hand, multiplication of DNA phage obtained from an urban river on E. coli C plate was not affected by the temperature. Incubation of sewage sample showed the same tendency of multiplication potential that DNA phages were easy to grow but FRNA phages were not. When we consider adopting phage as an indicator for pathogenic virus, E. coli KI2A/λ (F+) seems more reasonable as a host strain because it can detect FRNA phage, than E. coli C which detects DNA phage easily multipliable in the environment.
