【摘要】 我们将保加利亚乳杆菌和嗜热链球菌培养在以１．０％碳酸钙作为缓冲剂的１２％脱脂乳中，使菌体浓度最高可达５．６９×１０９个／ｍｌ，在超速冷冻高心机中，从７０００ｒｐｍ，３５ｍｉｎ，４℃使菌体得到浓缩。浓缩的菌体以添加适当保护剂的１０％脱脂乳制成菌悬浮液，经真空冷冻干燥机干燥后得到每克含活菌数为４．２×１０１０个的高活力酸乳发酵剂。本发酵剂可直接用于制备酸奶，还制备生产发酵制。更多还原

【Abstract】 Lactobacillus.bulgaricus and Streptococcus thermophilus are cultured in 12 % skim-milk added with CaCO3(1. 0%) as a buffer. The maximum density of the cultured lactic acid bacteria can reach 5. 69 ×109 per ml. The bacterial cells are harvested by centrifugation at 7000 rpm 35 min at 4℃ and used to prepare eell suspensions in 12% skim-milk containing the suitable protector. The suspension may be lyophilized into the lactic acid bacteria powder with high viability (the number of viable cells 4. 2 X 10,’/g ). The powder can be used in yoghourt manufacture as freeze dried direct-to-vat cultures.更多还原