بخصوص سؤال د .شيماء
في التوضيح التالي , بتمنى يكون وافي ,
L. sporogenes grows in the temperature range of 35° C to 50° C; the optimum pH range is 5.5-6.5. Unlike other lactobacilli currently in clinical use, L. sporogenes can form spores. Sporulation is the development in microorganisms of bodies each wrapped in a protective coat (a natural process of microencapsulation in a calcium-dipicolinic acid- peptidoglycan complex). Under favorable conditions, the spores germinate into viable bacilli and carry on their life activities.
This property of spore formation by L. sporogenes is the main characteristic that makes it the probiotic of choice in clinical applications. On oral administration, these spores survive the acidic gastric environment and are activated due to the low pH, mechanical churning action of the stomach and the water in the gastric environment. The spore coats imbibe water, swell, and the increased water content causes a rise in the metabolic rate of the sporulated bacilli. Outgrowths begin to protrude from the spore-coats. The spores pass on to the duodenum where the outgrown cells germinate and transform into viable vegetative cells. They begin to proliferate in the small intestine,
multiplying rapidly. Usually,
germination takes place about four hours after ingestion.
A large supply of viable L. sporogenes is thereby ensured in the small intestine. These cells settle in the intestinal tract and continue their metabolic activities, producing lactic acid and probably bacteriocins, which render the intestinal environment non-conducive for the growth of harmful pathogenic bacteria. The maintenance of a low, constant level of lactic acid on the inner surface of the intestinal tract helps restore the microecological balance after antibiotic therapy. Antibiotic therapy may kill beneficial microbes which help in the synthesis of vitamins B and digestive enzymes.
Since L. sporogenes produces only L (+)-lactic acid,
it does not cause metabolic acidosis.