A STUDY ON THE INHIBITORY EFFECT OF LOCAL ISOLATES OF LACTOCOCCUSLACTIS AGAINST PENICILLUM SPP.

Abstract

The present study have been investigated the inhibition ability of Lactococcus lactis against Penieittium spp. and it's spores. Bacterial isolates have been grown using solid and liquid media. The best inhibition ability were tested on this fungi. Four methods were used to test this ability, these were: l.Disk assay, 2. Well diffusion, 3.Mixture of spores suspension and bacterial supernatant 4. Spores germination in the mixture of bacterial infiltrate and the growth media. All the above methods employed to select the best inhibtion for Peniciltium spp.Bacteriocins of lactococci were extractable using (NaOH) to neutralize the bacterial infiltrate. The ability ofpure infiltrates were selected to identify the best isolates.The results revealed that there were five isolates (Lc,, Lc2, Lc3, Lc^, Lc5) gave clear results in a disk assay method and the inhibition zones increased in infilterated isolates by using the well diffusion method. The third and fourth methods declare that there were good inhibitory ability for Lc4,Lc,j,Lc$ and the highest ability appear in isolate Lc4 but the lower and the decrease in the ability appear in isolates Lc, and Lc, when we used the bacteriocins.