Showing papers by "Michel Aigle published in 1994"

Detection of polygalacturonase, pectin-lyase and pectin-esterase activities in a Saccharomyces cerevisiae strain

Abstract: The catalytic capacity of several excreted pectinolytic enzymes obtained from various yeast strains was examined using in vivo and biochemical techniques. Of the 33 yeast strains studied, 30 were isolated from champagne wine during alcoholic fermentation. Only one yeast strain was found to excrete pectinolytic enzymes and was identified as Saccharomyces cerevisiae and designated SCPP. Pulsed-field gel electrophoresis and the polymerase chain reaction technique were used to characterize further this specific strain. Three types of pectinolytic enzymes were found to be excreted by SCPP: polygalacturonase, pectin-lyase and pectin-esterase. These enzymes allow pectin hydrolysis during cell growth.

Cloning and sequence analysis of the gene encoding Lactococcus lactis malolactic enzyme: Relationships with malic enzymes

Abstract: Malolactic enzyme is the key enzyme in the degradation of L-malic acid by lactic acid bacteria. Using degenerated primers designed from the first 20 N-terminal amino acid sequence of lactococcal malolactic enzyme, a 60-bp DNA fragment containing part of the mleS gene was amplified from Lactococcus lactis in a polymerase chain reaction. This specific probe was used to isolate two contiguous fragments covering the gene as a whole. The 1.9-kb region sequenced contains an open reading frame of 1623 bp, coding a putative protein of 540 amino acids. The deduced amino acid sequence reveals that lactococcal putative protein (Mlep) is highly homologous to the malic enzyme of other organisms. Expression of the mleS gene in Escherichia coli results in malolactic activity.

Sequence analysis of a 31 kb DNA fragment from the right arm of Saccharomyces cerevisiae chromosome II.

Abstract: The nucleotide sequence of a 31 352 bp fragment from chromosome II of Saccharomyces cerevisiae has been determined and analysed. The fragment originates from the right arm of chromosome II, located between the GAL7,10,1 and the PHO3,5 loci, at a distance of about 130 kb from the centromere. The sequence contains a tRNA tandem repeat and 17 open reading frames (ORFs) larger than 100 amino acids. One of them extends into adjacent DNA and is incomplete. The two tRNA genes, coding for a tRNAasp and a tRNAarg, and three of the ORFs, had been sequenced previously, i.e. HSP26, SEC18, and UBC4. Four other ORFs showed similarity with yeast genes; amino acid transporter genes, the RAD54, SNF2 and STH1 family, the SPS2 gene and the bromodomain of SPT7, respectively. Two showed homology with sequences from other organisms, i.e. with a Plasmodium falciparum gene encoding a surface antigen and with a gene from Saimirine herpes virus respectively. Three ORFs, YBR0726, YBR0735 and YBR0740 are completely contained in YBR0727, YBR0734 and YBR0739 respectively, and thus probably do not represent real genes. Two ORFs, YBR0727 and YBR0745 most likely contain an intron. The sequences have been deposited in the EMBL data library under Accession Number X76294.

Identification, cloning and expression of the malolactic enzyme

Abstract: The invention relates to a nucleic acid containing: (1) either the DNA sequence itself contained in the nucleic acid represented in figure 5 and stretching from position 210 to position 1829; (2) or a portion of this sequence, this sequence being however sufficient to express in the appropriate host, after having been included beforehand in a vector allowing the transformation of this host, a polypeptide having a malolactic enzymatic activity; (3) or a sequence derived from either of the sequences defined in (1) or (2) by substitution of one or more of their nucleotides, or even addition or deletion of certain codons, as long as this sequence continues to code for a polypeptide having the abovementioned enzymatic activity