2.2. Screening for enzymes associated in virulent factors of P. acnes
Inocula were prepared by subculturing isolates on supplemented
BHI agar and incubated under anaerobic condition at 37 C
for 72 h. The isolates were inoculated into supplemented BHI broth
for 24 h and then transferred to supplemented BHI agar with 1%
tributyrin (Fluka, Buchs, Switzerland) to study lipase activity and
2% casein (Sigma, Steinhelm, Germany) for protease enzyme. The
inoculated plates were incubated at 37 C for 72 h under anaerobic
condition. The presence of clear zone was taken as an indication of
lipase activity. The isolates producing opalescent zones around the
colony were identified as protease positive.