16 



Perspectives in Microbiology 



for great, and C for clear) and IGT (T for turbid), both 

 being temperate. And it turned out (see Table I) that 

 lysogenic strains M[1GT] and Mox[lGT] were inducible, 

 whereas M[1GC] and Mox[lGC] were not. Then, from the 

 noninducible, defective lysogenic strain, a nonlysogenic 

 variant was isolated which will be called 9 IB. This strain, 

 when lysogenized with phages 1+, IGT, or IPT (P for 

 petite), gave rise to noninducible systems only, whereas 

 the strains M and Mox, lysogenized with the same phages, 

 gave rise to inducible systems. 



TABLE /. Inducibilify in Bacillus megaferium as Controlled by 

 the Genetic Constitution of the Bacterium and of the Bacterio- 

 phage * 



Inducible Systems 



Noninducible Systems 



899[1+] 

 M[l+] 

 Mox[l+] 

 17[2][1+] 

 10[3] [1+] 



M[1GT] 

 Mox[lGT] 



M[1PT] 

 Mox[lPT] 



lOfS] 

 M[3] 

 Mox[3] 

 91 B[3] 



91 B[l+] 



91 B[1GT] 

 91 B[1PT] 



M[1GC] 

 Mox[lGC] 

 91 B[1GC] 



* From the results of lonesco (5, 6). 



Thus a given phage may produce an inducible system in 

 a given bacterial strain and a noninducible system in 

 another. 



When strains Mox and M were lysogenized with the 

 phage produced by any of the noninducible lysogenic 

 strains 91B[1 + ], 91B[1PT], 91B[1GT], only inducible 



