关键词: 乳酸菌, 缓冲性能, 乳清培养基

Abstract: In this study, whey-based media were used for growing L.bulgaricus and S.thermophilu so as to obtain new type of industrial fermentation medium for preparing dairy starter cultures. It proved that the internal pH controlled whey-based medium has desirable nutrition and buffer effect. After S.thermophilu was cultivated at 42℃ for 3 hours, its cell population reached 0.29×109CFU/ml, and after S.thermophilu was cultured for 6 hours the viable cells attained to 0.42×109CFU/ml. When provided with external pH control through addition of 20% anhydrous ammonia, the viable cells population of L.bulgaricus and S.thermophilu reached 1.85×109CFU/ml and 3.65×108CFU/ml respectively, which was respectively 7 times and 3.5 times as much of the medium without phosphate.

Key words: lactic acid bacteria, buffer capacity, whey-based medium