The invention provides a process for the 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 ybbT, ywkA, yjmC, ytsJ, mdh, cysK, iolJ, pdhD, yuiE, dhaS, adk, yusH, yqhJ, yqjK and yqhI.