All subsp. lactis isolates were able to coagulate milk (10% RSM)
although at different rates (18 to 48 h). The two subsp. cremoris
strains (M23-10 and M16-10) failed to coagulate milk even after
extended incubation of 7 days. However, these cremoris strains
fermented milk in less than 18 h when the culture was supplemented
with 0.5% glucose (Table 2). The results show that the two cremoris
strains have a functioning proteolytic system but compromised lactose
utilization ability. A similar result has been reported recently by
Gutiérrez-Méndez et al. (2010) where plant L. lactis isolates showed
the slowest growth rates and yield when lactose was used as energy
source, compared to those obtained when glucose was used as carbohydrate
source