Abstract:Medium-temperature Torulopsis versatilis is an important microorganism in soybean paste fermentation.The fermentation process under high temperature may lead to the inability of medium-temperature T.versatilis to grow，resulting in the low quality of soybean paste. To improve the quality of soybean paste，a M-7 new strain with stable thermotolerance was constructed by genome shuffling with T. versatilis as the starting strain.The results of random amplified polymorphic DNA（RAPD）showed that the genetic structure of M-7 was different from that of its parents，indicating the successful genome shuffling. As compared with T. versatilis，the content of amino acid nitrogen and total nitrogen in soybean paste fermented by M-7 at high temperature（37 ℃and 42 ℃）were significantly increased by 12.20% and 12.03% （P＜0.05），respectively.M-7 effectively improved the relative content and diversity of various flavor compounds and sensory characteristics of soybean paste. In addition，the total content of biogenic amines produced by M-7 was less than 1 000 mg/L stipulated by the European Food Safety Authority，which ensured the safety of soybean paste. Overall，the thermotolerant M-7 new strain could significantly improve the quality of soybean paste and had a wide application prospect.