摘要:
The invention provides a complex inducible promoter system from a phage of a lactic acid bacterium, especially one having the DNA sequence of SEQ. ID. No: 3 given in FIG. 2, or a DNA sequence essentially corresponding to those sequences, and a modification of (an essential part of) such promoter system in which the mitomycin C induction system is replaced by a good-grade system, e.g. a temperature-initiated induction system or a salt-initiated induction system. Also is provided a recombinant vector and a transformed lactic acid bacterium comprising (an essential part of) such promoter system. Further a process for producing a desired protein by such transformed bacterium is provided, comprising expressing a gene encoding said desired protein or a precursor thereof under control of such promoter system or an essential part thereof. Preferably, the transformed lactic acid bacterium is made food-grade due to using food-grade DNA sequences and/or removing non-food-grade DNA sequences. When required, the desired protein can be secreted by the lactic acid bacterium if a DNA sequence fused to the gene encoding the desired protein is present which effects secretion of the desired protein or its precursor. The process can be used in a fermentation process, in which the desired protein causes lysis of the bacterial cells so that the contents of the cells can be released, or in which the desired protein is an enzyme involved in flavour formation, or in which the desired protein has a function in a cheese production process, such as chymosin or a precursor thereof, or an enzyme involved in flavour formation.
摘要:
The invention provides a process for the lysis of a culture of lactic acid bacteria, or a product containing such culture e.g. cheese, by means of a lysin through the in situ production of a homologous autolysin, or a heterologous autolysin obtainable from Gram-positive bacteria esp. from lactic acid bacteria. The gene encoding said autolysin is controlled by a promoter, preferably regulated by food-grade ingredients or parameters, to achieve an enhanced lysis after induction resulting in an enhanced production of total autolysin compared with the natural production lever of the homologous autolysin during fermentation or shortly thereafter. Other uses of the invention include preparing a mixture of peptides which are modified by peptidases freed after the lysis, using the autolysin as a bactericidal agent against spoiling bacteria or pathogenic bacteria for improving the shelf life of a product containing the lysed culture.
摘要:
The invention relates to surface display of proteins on micro-organisms via the targeting and anchoring of heterologous proteins to the outer surface of cells such as yeast, fungi, mammalian and plant cells, and bacteria. The invention provides a proteinaceous substance comprising a reactive group and at least one attaching peptide which comprises a stretch of amino acids having a sequence corresponding to at least a part of the consensus amino acid sequence listed in FIG. 10 and comprises a method for attaching a proteinaceous substance to the cell wall of a micro-organism comprising the use of said attaching peptide.
摘要:
The invention relates to surface display of proteins on microorganisms via the targeting and anchoring of heterologous proteins to the outer surface of cells such as yeast, fungi, mammalian, plant cells, and bacteria. The invention provides a proteinaceous substance comprising a reactive group and at least one attaching peptide including a stretch of amino acids having a sequence corresponding to at least a part of the consensus amino acid sequence listed in FIG. 10 and further includes a method for attaching a proteinaceous substance to the cell wall of a microorganism comprising the use of the attaching peptide.
摘要:
The invention relates to surface display of proteins on microorganisms via the targeting and anchoring of heterologous proteins to the outer surface of cells such as yeast, fungi, mammalian, plant cells, and bacteria. The invention provides a proteinaceous substance comprising a reactive group and at least one attaching peptide including a stretch of amino acids having a sequence corresponding to at least a part of the consensus amino acid sequence listed in FIG. 10 and further includes a method for attaching a proteinaceous substance to the cell wall of a microorganism comprising the use of the attaching peptide.
摘要:
The invention provides a salt-inducible promoter present in SEQ ID NO: 10 and derivable from a lactic acid bacterium in isolation from the coding sequence normally controlled by said promoter in a wild-type lactic acid bacterium, with modifications and important parts thereof. Also provided are a recombinant vector and a transformed lactic acid bacterium comprising such promoter, and the production of a desired protein by such transformed bacterium, whereby the gene encoding said desired protein or a precursor thereof is expressed under control of such promoter. The desired protein can be secreted by the bacterium due to the presence of a signal sequence. The action of the salt-inducible promoter is enhanced at a pH of about 4-4.5 and/or by the presence of glutamic acid. Such process can be used in a fermentation process, in which the desired protein is a lytic protein causing lysis of the cells and release of the cell content. Or the desired protein can be an enzyme involved in flavour formation, e.g. in producing dressings, spreads, sausages and sour dough, or a protein functioning in a cheese production process, such as chymosin or a precursor thereof, or an enzyme involved in cheese flavour formation.
摘要:
The invention relates to surface display of proteins on microorganisms via the targeting and anchoring of heterologous proteins to the outer surface of cells such as yeast, fungi, mammalian, plant cells, and bacteria. The invention provides a proteinaceous substance comprising a reactive group and at least one attaching peptide including a stretch of amino acids having a sequence corresponding to at least a part of the consensus amino acid sequence listed in FIG. 10 and further includes a method for attaching a proteinaceous substance to the cell wall of a microorganism comprising the use of the attaching peptide.
摘要:
The claimed invention is drawn to a recombinant plasmid which can replicate in Bacillus subtilis, Escherichia coli, and lactic acid Streptococcus bacteria comprising the replication of origin from Streptococcus cremoris plasmid pWV01 as its origin of replication, in addition to coding marker genes and genes of interest which code for improved fermenting properties.
摘要:
The subject invention describes the cloning and overexpression of leader peptidase genes. A method for isolating a leader peptidase gene is disclosed. Overexpression of the signal peptidase in a suitable host species leads to an enhanced rate of protein processing.
摘要:
Novel vectors are provided for identifying secretory signal sequences from DNA fragments of unicellular microorganisms. The plasmids comprise a multiple cloning site with restriction sites in reading frame with a structural gene which permits rapid screening of the screted expression product. Optionally, the vectors may include a promoter region upstream from the multiple cloning site. The invention is exemplified with Bacillus. Specific secretory signal sequence have been isolated with those vectors, allowing for efficient secretion into the supernatant, and not just to the periplasmic space to provide proteins in economically high yields. Secretory sequences are provided superior to other previously known sequences.