Diacetyl and acetoin production from whey permeate using engineered Lactobacillus casei

• DOI: 10.1007/s10295-009-0617-9
• Publication Date: 2009-07-15T12:23:56Z
• Authors: Inmaculada Nadal; Juan Rico; Gaspar Pérez-Mart...; María J. Yebra; Vicente Monedero
• Keywords: 2. Zero hunger; 0106 biological sciences; L-Lactate Dehydrogenase; Acetoin; Lactose; Pyruvate Dehydrogenase Complex; Diacetyl; Milk Proteins; 01 natural sciences; Whey permeate; Culture Media; Lactobacillus; Acetolactate Synthase; Lacticaseibacillus casei; Whey Proteins; Fermentation; Mutation; Genetic Engineering; Metabolic engineering; Biotechnology

The capability of Lactobacillus casei to produce the flavor-related compounds diacetyl and acetoin from whey permeate has been examined by a metabolic engineering approach. An L. casei strain in which the ilvBN genes from Lactococcus lactis, encoding acetohydroxyacid synthase, were expressed from the lactose operon was mutated in the lactate dehydrogenase gene (ldh) and in the pdhC gene, which codes for the E2 subunit of the pyruvate dehydrogenase complex. The introduction of these mutations resulted in an increased capacity to synthesize diacetyl/acetoin from lactose in whey permeate (1,400 mg/l at pH 5.5). The results showed that L. casei can be manipulated to synthesize added-value metabolites from dairy industry by-products.