Abstract: Cultures of Lactobacillus delbrueckii sp. bulgaricus play an important role in the production of fermented foods and are frequently used as starter cultures for dairy fermentations combined with other species. It These cultures is are particularly used in the industrial production of yoghurt and cheeses. Large scale Pproduction methods of dried L. bulgaricus powders, for inoculating the production vat directly, involve treatments that stress cells in such a way that they lose some of their original activity. containing viable and active organisms which are long-term preserved during storage in the dried state, areis presented. This review covers the environmental stress responses in cells of L. bulgaricus which have been investigated. The responses of L. bulgaricus cells to heat, cold, acid, osmotic, oxygen, starvation, drying and during storage in the dried state are described. Attempts to improve the survival of L. bulgaricus during drying and subsequent storage in the dried state are also discussed in this review.