The invention provides a process for the fermentative preparation of D-pantothenic acid and/or salts thereof or feedstuffs additives comprising these by fermentation of microorganisms of the Bacillus group, in particular those which already produce D-pantothenic acid, which comprises enhancing, in particular over-expressing, in the microorganisms one or more of the nucleotide sequence(s) which code(s) for the gene or ORF serA, serC, ywpJ or glyA.