Growth rates of Bacillus species probiotics using various enrichment media

Document Type : Original Article


1 Department of Food Hygiene and Public Health, School of Veterinary Medicine, Shiraz University, Shiraz, Iran

2 Nutrition Research Center, Department of Food Hygiene and Quality Control, School of Nutrition and Food Sciences, Shiraz University of Medical Sciences, Shiraz, Iran


Background: Probiotics are well-known as valuable functional foods to promote specific health benefits to consumers. Some Bacillus bacteria have been recently considered as probiotic and food additives. We aimed to investigate the growing
rate of probiotic B. subtilis and B. coagulans using several enrichment media incubated at 37 °C for 24 hours.
Methods: Various enrichment media including nutrient broth (NB), tryptic soy broth (TSB), double strength TSB, Mueller Hinton broth (MH), brain-heart infusion broth (BHIB), de Man, Rogosa and Sharpe (MRS), and nutrient yeast extract salt medium (NYSM) were used to enrich the probiotics and they were subsequently incubated for 18 h at 37 °C. The bacteria were then enumerated on TSA medium.
Results: The results showed that B. subtilis ATCC 6633, B. subtilis PY79, and B. coagulans developed in TSB, double strength TBS, TSB yeast extract, BHIB and NYSM, respectively. Moreover, the formulas were achieved based on the optical density curve and the number of bacteria.
Conclusion: Considering that the probiotics are significantly employed as food supplements, it is essential to identify appropriate enrichment media to proliferate these beneficial bacteria.