目前发酵乳商用发酵剂多为保加利亚杆菌和嗜热链球菌，市售发酵乳风味相似。因此深度挖掘我国特色发酵乳制品微生物资源，有助于特色发酵乳的研发。本项目将采用比较基因组学解析不同生境来源的瑞士乳杆菌的生物多样性，构建瑞士乳杆菌基因组规模代谢网络模型；依据瑞士乳杆菌与嗜热链球菌的基因组信息及其在发酵过程中的动态变化、互作机制、代谢物质的产生与变化，解析其互作机制，以不同碳源、氮源利用为模拟条件，进行35种碳源和20种氮源的模拟分析，预测嗜热链球菌与瑞士乳杆菌的生长状况及代谢物质的生成情况，构建瑞士乳杆菌与嗜热链球菌的代谢互作网络模型；选取牛乳体系为模型体系，计算该体系的典型碳源和氮源条件，对嗜热链球菌与瑞士乳杆菌的生长情况及风味物质的生成情况进行预测；选取呈现不同风味特征的瑞士乳杆菌与嗜热链球菌复配，通过检测发酵体系的产酸情况、挥发性与非挥发性风味物质的生成情况，进行感官评价，开发特色风味发酵乳制品。

The most common commercial starter cultures for fermented milk are lactobacillus delbrueckii subsp. Bulgaricus and streptococcus thermophiles, and lead into the similar flavor profile of commercial fermented milk. Therefore deep mining of the microbial biodiversity of Chinese traditional fermented dairy products would benefit the development of new fermented milk products. In the present study comparative genomic analysis will be conducted to explore the biodiversity of lactobacillus helveticus and construct the genome scale metabolic model of lactobacillus helveticus. Then based on the interaction of lactobacillus helveticus and streptococcus thermophiles and the genomic information genome scale metabolic model of these two bacteria will be constructed for regulation of the flavor profile of fermented milk products. Strains of lactobacillus helveticus with different metabolic characterization will be applied together with streptococcus thermophiles for production of fermented milk and evaluated by acid production, volitle and non-volatile compound formation and sensory evaluation.