For all further studies, we focused on BB (Figure ) as a formulation component, selectively protecting phages against UV. First, we tested the protective properties of BB on other phages. All non-enveloped phages were protected against UV (Figure ). LR1_PA01 is a phage isolated from the environment with Pseudomonas aeruginosa as a host. vB_SauS_CS1 is S. aureus (Grampositive bacteria) phage. P22 infects S. enterica. Values of EC50 of BB varied slightly depending on the phage (T4 -0.32%, MS2 -0.42%, M13 -0.41%, P22 -0.32%). The exemplary dependence of survival rate and BB concentration is given in Figure . BB, even without UV, harmed Phi6 -an enveloped phage (not shown).