In our experiments mesophilic bacteria and Pseudomonas spp., growing faster than coliforms, recorded higher II average values (0.713 and 0.850, respectively) already at day 2. After two days of cold storage higher II values in Pseudomonas spp. (0.958) and mesophilic bacteria (0.829) were found in the governing liquid amended with 50 mg mL 1 of LFH in samples B and A. Since coli- forms grew more slowly, II was calculated at day four recording average values of 0.399, 0.511 and 0.765 for samples A, B and C, respectively. As concerns differences between LFH concentrations, higher amounts of LFH usually had a higher inhibition effect even though with differences not statistically significant.