[en] Bacillus probiotic have been extensively studied and isolated since many years from different food products. Although generally used in dairy products, they also widely used in various commercial food such as fermented meats, cereals, baby foods, fruits juices and ice creams.
The interest to study the Bacillus species is related to their ability to produce spores that have several advantages compared to non-spores-forming Lactobacillus species which are used as probiotics. Their benefits are linked to spore resistance to heat, chemical agents and enzyme degradation. In the form of spore, Bacillus species can be stored at room temperature , without any deleterious effect on their viability. They can survive in acid conditions of the stomach and so grow in the intestines in which they can play the role of probiotics.
In the present study, we follow the expression of spoIIE gene, which plays a crucial role in B. subtilis, B. licheniformis and B. coagulans sporulation, by following the expression of a chimeric gfp gene under the control of spoIIE promoter. In our studies, cultures were carried out in Erlenmeyer flasks (250 ml) and in Fermenter (20 L), in the absence and in presence of two carbon sources: glucose and xylose.
Our results shows that in both B. licheniformis DSM13 /PspoIIE-gfp and B. subtilis PspoIIE-gfp, the expression of spoIIE gene was slightly affected by the presence of xylose in the culture media. While the presence of glucose inhibit the expression of spoIIE gene and the sporulation of the strain.
