Abstract: An object to be solved by the present invention is to provide, for example, a method for producing a Kluyveromyces marxianus transformant by a method for conveniently and efficiently connecting the ends of DNA fragments without using specific restriction enzymes or their recognition sequences, and a method for producing a useful substance using the transformant.

Abstract: An object to be solved by the present invention is to provide, for example, a method for producing a Kluyveromyces marxianus transformant by a method for conveniently and efficiently connecting the ends of DNA fragments without using specific restriction enzymes or their recognition sequences, and a method for producing a useful substance using the transformant.

Abstract: It is to provide a novel Kluyveromyces marxianus transformant having thermotolerance and flocculation property, suitable for the industrial production of bioethanol, by introducing a foreign flocculation gene into Kluyveromyces marxianus, and an efficient method for producing the transformant. The present inventors focused on the flocculation gene FLO of Saccharomyces cerevisiae as a foreign gene to confer flocculation property to Kluyveromyces marxianus and produced a linear DNA fragment comprising a known expression promoter sequence and a FLO gene sequence derived from Saccharomyces cerevisiae. As a result of introducing this linear DNA fragment into Kluyveromyces marxianus, the present inventors have confirmed that Kluyveromyces marxianus transformant can be obtained efficiently, and that the flocculation property of the above transformant is unexpectedly and significantly enhanced. The present invention has been thus completed.

Abstract: It is to provide a novel Kluyveromyces marxianus transformant having thermotolerance and flocculation property, suitable for the industrial production of bioethanol, by introducing a foreign flocculation gene into Kluyveromyces marxianus, and an efficient method for producing the transformant. The present inventors focused on the flocculation gene FLO of Saccharomyces cerevisiae as a foreign gene to confer flocculation property to Kluyveromyces marxianus and produced a linear DNA fragment comprising a known expression promoter sequence and a FLO gene sequence derived from Saccharomyces cerevisiae. As a result of introducing this linear DNA fragment into Kluyveromyces marxianus, the present inventors have confirmed that Kluyveromyces marxianus transformant can be obtained efficiently, and that the flocculation property of the above transformant is unexpectedly and significantly enhanced. The present invention has been thus completed.