Time MRS MS MSSM pH Lactic acid bacteria cell population log10 (CFU/g) pH Lactic acid bacteria cell population log10 (CFU/g) pH Lactic acid bacteria cell population  log10 (CFU/g) Before incubation 6.33 ± 0.03 6.50 ± 0.70 6.33 ± 0.03 6.50 ± 0.70 6.33 ± 0.03 6.50 ± 0.70 After 20h of incubation 4.44 ± 0.06 9.50 ± 0.71 3.41 ± 0.01 6.40 ± 0.60 4.21 ± 0.12 8.50 ± 0.60

a (MRS): Man, Rogosa and Sharpe broth used as reference b (MS): Millet flour and salt (NaCl) in distilled water at the ratio [(2 + 0.5) : 100 (w/v)] c (MSSM): Millet flour and salt (NaCl) in distilled water at the ratio [(2+ 0.5) : 100 (w/v)] followed by supplementation of the resulting solution with skimmed milk at the ratio 1:9 (v/v)

Table 1: Level of pH and lactic acid bacteria cell population in standard medium a and millet flour based substratesb,c seeded with revitalized nisinogenic Lactococcus lactis subsp. lactis CWBI-B1410 before and after 20h of incubation at 30°C. The data are the mean ± standard deviation from duplicate trials performed on different samples at different times.