An ectoine-producing recombinant yeast, in the genome of which: (i) at least one nucleic acid encoding an aspartokinase is overexpressed and/or is under the control of an inducible or repressible promoter; and/or (ii) at least one nucleic acid encoding an aspartate kinase is overexpressed and/or is under the control of an inducible or repressible promoter; at least one nucleic acid encoding an aspartate semi-aldehyde dehydrogenase and/or at least one nucleic acid encoding an aspartate semi-aldehyde dehydrogenase that can use as coenzyme both NAD and NADP is overexpressed and/or is under the control of an inducible or repressible promoter; at least one nucleic acid encoding a diaminobutyrate aminotransferase is overexpressed and/or is under the control of an inducible or repressible promoter; (i) at least one nucleic acid encoding an homoserine-O-acetyltransferase MET2 is overexpressed and/or is under the control of an inducible or repressible promoter; (ii) at least one nucleic acid encoding an homoserine-O-acetyltransferase METX is overexpressed and/or is under the control of an inducible or repressible promoter, and/or (iii) at least one nucleic acid encoding a diaminobutyric acid acetyltransferase is overexpressed and/or is under the control of an inducible or repressible promoter; at least one nucleic acid encoding an ectoine synthase is overexpressed and/or is under the control of an inducible or repressible promoter; (i) at least one, preferably all, endogenous nucleic acid encoding an homoserine dehydrogenase has been deleted and/or interrupted, and/or (ii) at least one, preferably all, nucleic acid encoding an homoserine dehydrogenase is independently: - under the control of an inducible or repressible promoter; - under the control of a weak promoter; and/or - in a destabilized form. (i) at least one nucleic acid encoding an aspartokinase is overexpressed and/or is under the control of an inducible or repressible promoter; and/or (ii) at least one nucleic acid encoding an aspartate kinase is overexpressed and/or is under the control of an inducible or repressible promoter; (i) at least one nucleic acid encoding an aspartokinase is overexpressed and/or is under the control of an inducible or repressible promoter; and/or (ii) at least one nucleic acid encoding an aspartate kinase is overexpressed and/or is under the control of an inducible or repressible promoter; at least one nucleic acid encoding an aspartate semi-aldehyde dehydrogenase and/or at least one nucleic acid encoding an aspartate semi-aldehyde dehydrogenase that can use as coenzyme both NAD and NADP is overexpressed and/or is under the control of an inducible or repressible promoter; at least one nucleic acid encoding a diaminobutyrate aminotransferase is overexpressed and/or is under the control of an inducible or repressible promoter; (i) at least one nucleic acid encoding an homoserine-O-acetyltransferase MET2 is overexpressed and/or is under the control of an inducible or repressible promoter; (ii) at least one nucleic acid encoding an homoserine-O-acetyltransferase METX is overexpressed and/or is under the control of an inducible or repressible promoter, and/or (iii) at least one nucleic acid encoding a diaminobutyric acid acetyltransferase is overexpressed and/or is under the control of an inducible or repressible promoter; (i) at least one nucleic acid encoding an homoserine-O-acetyltransferase MET2 is overexpressed and/or is under the control of an inducible or repressible promoter; (ii) at least one nucleic acid encoding an homoserine-O-acetyltransferase METX is overexpressed and/or is under the control of an inducible or repressible promoter, and/or (iii) at least one nucleic acid encoding a diaminobutyric acid acetyltransferase is overexpressed and/or is under the control of an inducible or repressible promoter; at least one nucleic acid encoding an ectoine synthase is overexpressed and/or is under the control of an inducible or repressible promoter; (i) at least one, preferably all, endogenous nucleic acid encoding an homoserine dehydrogenase has been deleted and/or interrupted, and/or (ii) at least one, preferably all, nucleic acid encoding an homoserine dehydrogenase is independently: - under the control of an inducible or repressible promoter; - under the control of a weak promoter; and/or - in a destabilized form. (i) at least one, preferably all, endogenous nucleic acid encoding an homoserine dehydrogenase has been deleted and/or interrupted, and/or (ii) at least one, preferably all, nucleic acid encoding an homoserine dehydrogenase is independently: - under the control of an inducible or repressible promoter; - under the control of a weak promoter; and/or - in a destabilized form. - under the control of an inducible or repressible promoter; - under the control of a weak promoter; and/or - in a destabilized form.