Abstract: The present invention provides a bacterial continuous evolution system, an orthogonal error-prone DNA polymerase, and a continuous evolution method. In the present invention, by combining an orthogonal DNA replication system and an orthogonal error-prone DNA polymerase, a continuous evolution method that includes all mutant types, enables long-DNA-fragment mutation, and is good in continuity and simple and convenient to operate is obtained. By inducing the opening and closing of DNA polymerase expression, switching between a linear plasmid error-prone mutation process and a high-fidelity replication process is realized, so as to achieve the efficient and continuous evolution of a target DNA sequence.

Abstract: The invention provides a Saccharomyces cerevisiae strain for producing a human milk lipid substitute. By integrating a heterologous lysophosphatidic acid acyltransferase into Saccharomyces cerevisiae and knocking out its own natural lysophosphatidic acid acyltransferase, the content of palmitic acid (C16:0) at Sn-2 position of triacylglycerol produced by Saccharomyces cerevisiae is increased, to synthesize a human milk lipid substitute. On this basis, a metabolic pathway related gene is knocked out, to further increase the content of human milk lipid substitute in the product. In the present invention, a human milk lipid substitute is de novo synthesized by Saccharomyces cerevisiae for the first time, in which the total fatty acid is 15% or more, and the relative content of C16:0 at Sn-2 position reaches about 60%.

Abstract: The present invention relates generally to frozen dairy products made with modified milk filled with vegetable oil that is preferably naturally high in monounsaturated fatty acids (MUFA). The invention further makes use of carbohydrates having a low glycemic index in place of sucrose. As well as being nutritionally unique, the product achieves a stability, taste and organoleptic quality of a regular frozen dessert such as ice cream comprising regular milk fat and sugar.