Modification of media using food-grade components for the fermentation of and strains in large-scale bioreactors.

Probiotic bacteria continue to receive increasing attention in the food and feed industries. However, the production of and at an industrial scale is challenging because of specific nutrient requirements and conditions, which are complicated and costly. We developed low-cost culture media by modifying the carbon and nitrogen sources for subsp. KMP-H9-01 and KMP-P4-S03 from available food grade components. Sucrose (15 g/l) was selected as a suitable carbon source for both strains because it was the most economic and facilitated bacterial growth that was equal to that of glucose. The strain required beef extract as a nitrogen source to multiply. The fermentation of both strains using the modified media formula in 5-L and 50-L bioreactors showed that the highest cell counts of and subsp. were 9 and 9.8 log CFU/ml after 12-15 h, respectively. The concentration (g/l) ratio between lactate and acetate obtained from subsp. was 7:7.4 at 12 h and 11.4:10.6 at 40 h; the ratio was similar at both time points (6.9: 1.1) for . Thus, this economically modified food-grade medium for the large-scale fermentation of two probiotic bacteria was efficient.