A general method for selection of alpha-acetolactate decarboxylase-deficient Lactococcus lactis mutants to improve diacetyl formation

Article Abstract:

Dairy lactococcal strains without the enzyme acetolactate decarboxylase (Ald) have been isolated by introducing genes that encode enzymes involved in the biosynthesis of branched-chain amino acids. Ald regulates the alpha-acetolactate pool in pyruvate catabolism and in the synthesis of isoleucine, leucine and valine (ILV). These mutants can be selected as leucine-resistant mutants in ILV- or IV-prototrophic strains. Western blotting with Ald-specific antibodies was used in detecting the presence of Ald in the mutants.

Genetic aspects, Lactobacillus, Bacterial genetics, Microbial enzymes

---

Mutational analysis of the feedback sites of phenylalanine-sensitive 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase of Escherichia coli

Article Abstract:

The in vitro chemical mutagenesis of the cloned Escherichia coli aroG gene identifies the residues and regions of 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase that are essential for phenylalanine (Phe) feedback inhibition. Mutations at the D146N and P150L residues abolish the inhibition of the synthase by Phe. The study indicates that the 146-150 residues constitute an aromatic acid-binding site that is necessary for Phe-induced suppression.

Physiological aspects, Gene mutations, Gene mutation, Phenylalanine

---

Protein trans-splicing to produce herbicide-resistant acetolactate synthase

Article Abstract:

Researchers introduced a gene for herbicide resistance into E. coli by fusing the gene for acetolactate synthase II to the DnaE intein from Synechocystis sp. strain PCC6803. The DnaE intein reconstitutes a functional protein via trans-splicing.

Plant genetic engineering, Herbicide resistance

Similar abstracts:

• Abstracts: Genetic localization and regulation of the maltose phosphorylase gene, MaIP, in Lactococcus lactis. Product formation and phosphoglucomutase activities in Lactococcus lactis: cloning and characterization of a novel phosphoglucomutase gene
• Abstracts: Ultrastructure of surface components of Streptococcus gallolyticus (S. bovis) strains of differing virulence isolated from pigeons
• Abstracts: The immunoreactive 116 kDA surface protein of Mycoplasma pneumoniae is encoded in an operon. Defining the mycoplasma 'cytoskeleton' : the protein composition of the Triton X-100 insoluble fraction of the bacterium Mycoplasma pneumoniae determined by 2-D gel electrophoresis and mass spectrometry

This website is not affiliated with document authors or copyright owners. This page is provided for informational purposes only. Unintentional errors are possible.