Caractérisation et contrôle de la qualité de ferments lactiques utilisés dans l’industrie laitière algérienne.

Abstract

The manufacture of fermented dairy products requires the incorporation of large amounts of imported starter cultures. The robustness of industrial starters with respect to fluctuations in operating parameters of industrial processes is a quality that is valued by industrial operators. Therefore, the most effective strains under harsh industrial conditions tend to be selected in the screening operations that lead to the development of industrial strains. Strains demonstrating resistance to antibiotics are but one example. Antibiotic resistance may be innate or acquired after exposure of a particular strain to antibiotics. The use of antibiotics in animal production is considered the main cause of selection for antibiotic resistance in bacteria that can then be found on food. Several scientific studies support the hypothesis of a link between the use of antibiotics in primary production and the emergence of antibiotic resistance in human pathogens, with food being a major vector of transmission. Our work contains three main parts: (1) quality control and identification of bacterial strains present in samples of imported starter cultures, (2) evaluation of the susceptibility of imported starters to a panel of three antibiotics chosen because of their use in milk production, (3) consultation with a panel of scientific experts and industrial operators by means of a Delphi survey in order to assess the potential for local manufacture of indigenous dairy starter cultures. Our results showed a good proliferation of the majority of strains of lactic acid bacteria present in the imported starters in the presence of the antibiotics tested, notably Sulfaprime S with a concentration of up to 350 g/ml. This could pose a potential danger to the health of consumers, in particular the risk of horizontal transfer of the resistance genes to human intestinal flora or, in the worst case, to pathogens therein. The results collected from the Delphi survey suggest that the sustainable development of the Algerian dairy industry would depend on the availability of raw materials, especially cow's milk and imported milk powder whose price is subject to fluctuations in international markets. As for Production of indigenous dairy starter cultures, our results indicate that it would depend on the acquisition of technical know-how, in particular in the field of industrial fermentation, but also mastery of modern tools for molecular characterization and high-throughput screening in order to identify viable alternatives, both commercially and technologically, to the imported starter cultures which are perceived favorably by industrial operators because of their reliability, despite the risks associated with them (bacteriophages, GMO, antibiotic resistance ... etc.).