Stichting Nederlands Instituut Voor Zuivelonderzoek (nizo)

Nederlands Instituut Voor Zuivelonderzoek

Stichting Nederlands Instituut Voor De Zuivelinderzoek

Oscar Paul Kuipers

Willem Meindert De Vos

Roelant J Siezen

Pascal Hols

Michiel Kleerebezem

Jean Marcelin Alain Marie Ghislain Delcour

Thierry Ferain

A process for preparing alanine by culturing a genetically modified microorganism that produces alanine from glucose. The microorganism is one that has been modified to result in an overexpression of an endogenous alanine dehydrogenase gene, expression of a heterologous alanine dehydrogenase gene, or a combination of both. The source of alanine dehydrogenase may be The modified microorganisms may be a homofermentative microorganism, such as a strain of . The process can be used for in situ and stereoscopic preparation of alanine. The invention also relates to the microorganisms and the recombinant DNA molecules that can be used in the invention, as well as to alanine and alanine-containing products obtained according to the process of the invention.

Process for the production of alanine by recombinant microorganisms

The invention relates primarily to a number of lantibiotics similar to nisin A, which differ from nisin A by substitution, deletion or insertion of one or more amino acids, such as, in particular, the naturally occurring analogue of nisin A, termed nisin Z, which has the structure given above. Lantibiotics of this type are particularly suitable for preserving foodstuffs for humans and animals. This preservation takes place by the use of these lantibiotics themselves or of microorganisms producing these lantibiotics, in particular lactic acid bacteria, in the preparation or storage of foodstuffs.

Lactic acid bacteria producing lantibiotics similar to nisin A

The present invention relates to a method for the controlled expression, in a lactic acid bacterium, of a DNA fragment containing one or more genes coding for a desired characteristic, wherein the DNA fragment is under the control of a promoter for a microbial gene which codes for an antimicrobial peptide, and the gene or genes are brought to expression on the DNA fragment by the addition of a suitable inducing factor for the transcription activation. The promoter is preferably the nisA promoter from Lactococcus lactis. The inducer is preferably acceptable for food products, and more preferentially is nisin or derivatives thereof. The invention also relates to a method for the production of proteins or RNA, as well as to a method for the preparation of dairy products using the expression system according to the invention. The invention finally relates to lactic acid bacteria and expression vectors for use in the method according to the invention.

Method for controlling the gene expression in lactic acid bacteria

Lantibiotics similar to nisin a

Growing community of inventors

Ede, Netherlands

Oscar Paul Kuipers