Response of Lactococcus lactis to glucose starvation

Adaptation of Lactococcus lactis towards progressive carbon starvation is mediated by three different types of transcriptomic responses: i) global responses, i.e. general decrease of functions linked to bacterial growth and lack of induction of the general stress response, ii) specific responses functionally related to glucose exhaustion, i.e. under expression of central metabolism genes, induction of alternative sugars transport and metabolism genes, induction of arginine deiminase pathway genes and iii) other responses never described previously during carbon starvation. Keywords: stress response, time course Glucose starvation was imposed by the consumption of this nutrient during the growth of Lactococcus lactis IL1403 on CDM medium and under controlled conditions (30 °C, pH 6.6, nitrogen atmosphere). Cell samples were harvested in exponential and deceleration phases and after 1.25 h and 3.5 h of glucose starvation. Total RNA was extracted from these samples and radiolabelled cDNA were prepared and hybridized on nylon arrays. 2053 amplicons specific of Lactococcus lactis IL1403 genes were spotted twice on the array. The 4 time-points were analyzed simultaneously and 3 independent repetitions were performed.