Purpose: To seek the cause of this low sporulation in absence of oxygen, we followed during growth the main genes (kinA, kinB, spo0F, spo0B, spo0A) involved in sporulation process.
Methods: Cells were grown in controlled batch cultures to study gene expressions by real-time RT-PCR using SYBR green technology on a light cycler instrument. A chemical defined medium was used (MODs).
Results: These experiments have shown that the expression of genes kinA, spo0F, Spo0, spo0B had the same kinetics with overexpression at the beginning and the end of the anaerobic growth compared to aerobic conditions. During growth, it was noted an under-expression of the gene kinA while spo genes showed no difference in expression under anaerobic conditions compared to aerobic conditions. In addition, kinB (kinB1, kinB2, kinB3) had a reverse trend of expression than previous genes. They showed no difference in expression compared to anaerobic aerobic early (2h) but also at the end (9h) of growth. After 2h of culture, the expression of genes kinB increased gradually until it reached expression peaks at 4h (kinB3) and 6h (kinB1 and kinB2) growth. We also note that the genes kinA and kinB have inverse expression levels. When kinA was overexpressed, kinB was subexpressed and vice versa. These results could assume that the role of kinB here is secondary or complementary to kinA.
Significance: This work thus provides new data on sporulation process in this food-born pathogenic bacterium