EXPERIMENTAL APPROACH TO THE INDUCTION OF NONCULTURABLE STATE OF LACTOCOCCUS LACTIS - Biochemistry and Biotechnology: Research and Development - page 47

maximum size (no separate colonies that appeared at the same time were observed on these
plates). It is possible that big colony produces some compounds that resuscitate some of
nonculturable cells around it. Strain 194 exhibited only white round colonies typical for L.
lactis (figure 3). Biosynthetic activity for antimicrobial compounds (bacteriocins) remained
unaltered. After 6 weeks of incubation number of CFU/ml increased four times. This was
preceded by significant more than one order of magnitude increase in numbers of dead cells
in the culture a week before. It is possible that some components of dead cells promoted
resuscitation of some VBNC cells that are the easiest to regain the ability to proliferate. These
data conform to published information on induction of nonculturable state in L. lactis
(Ganesan B. et al, 2007).
Figure 1. Colony morphology of Lactococcus lactis ssp. lactis strain 729.
Figure 2. Colony morphology of Lactococcus lactis ssp. lactis strain MGU.