50 results about "Lactonase" patented technology

The invention discloses an N-acylhomoserine lactonase, a production method thereof and a special recombinant bacterium. The N-acylhomoserine lactonase is protein consisting of an amino acid sequence shown in a sequence 2 in a sequence table. The invention also discloses an engineering bacterium which is the recombinant bacterium obtained by introducing the gene for coding the protein into pichia pastoris GS115. The recombinant bacterium has enzyme activity reaching 4034.71U/ml through fermentation.

Provided is a method for producing xylonic acid from xylose with a recombinant fungal strain that is genetically modified to express a xylose dehydrogenase gene, which is able to convert xylose to xylonolactone, which is spontaneously or enzymatically hydrolysed to xylonic acid. The xylonic acid is excreted outside the host cell. Xylonate production may be coupled with xylitol production. Alternatively, if xylitol production is not desired, its production is reduced by removing the aldose reductase (or specific xylose reductase) enzyme, which converts xylose to xylitol. Expression of a heterologous lactonase encoding gene may result in higher acid concentrations. The method is suitable for producing xylonic acid from a hemicellulose hydrolysate such as hydrolysed lignocellulosic plant biomass.

The invention discloses a heat-resisting N-acyl homoserine lactonase AiiA-AIO6 with high specific activity as well as a coding gene and application thereof. A protein provided by the invention is (a) or (b): the protein (a) is composed of amino acid sequences shown as a sequence 1 in a sequence table; the protein (b) is obtained through substituting and/or lacking and/or adding one or more amino acid residues of amino acid sequences shown as the sequence 1, has the activity of the N-acyl homoserine lactonase and is derived from the sequence 1. The AiiA-AIO6 protein provided by the invention is a novel N-acyl homoserine lactonase and the N-acyl homoserine lactonase is heat-resisting, has high specific activity, higher protease resistance and better capability of degrading each substrate and can be used as a novel bio-control enzyme preparation.

The invention discloses recombinant bacteria using xylose to produce glycollic acid and a building method and application of the recombinant bacteria and belongs to the technical field of genetic engineering. The xylose dehydrogenase gene, xylonic acid lactonase gene, xylonic acid dehydratase gene, 3-deoxygenation-D-glycerin ketopentose acid aldolase gene and glycolic aldehyde dehydrogenase gene in the recombinant bacteria using the xylose to produce the glycollic acid are overexpressed. Meanwhile, the invention further provides a preparation method of the recombinant bacteria and a method using the recombinant bacteria to produce the glycollic acid. By the recombinant bacteria, the biological synthesizing path using D-xylose as the carbon source to form the glycollic acid through glycolic aldehyde conversion is achieved for the first time.

The invention discloses a heat resistant N-acyl-homoserine lactonase AiiA-AI96 as well as a coding gene and application thereof. The lactonase is the protein as shown in a) or b) below, wherein a) is the protein formed by the amino acid sequence shown in SEQ IN NO:1, and b) is the protein derived from a) through the substitution and/or deletion and/or addition of one or more amino acid residues on the amino acid sequence shown in SEQ IN NO:1. The heat resistant lactonase disclosed by the invention has stronger protease resistance and better degradation capacity for various substrates, and can be used as a novel biocontrol enzymic preparation.

The invention discloses a DNA for high-level expression of N-acyl homoserine lactonase in yeasts and engineering bacteria constructed thereby. The DNA provided by the invention is the DNA expressed by the sequence 2 in a sequence list. On the basis of the traditional homoserine lactonase gene aiiaB546, the DNA sequence thereof is optimized to obtain the optimized gene aiiaB546 M by the method. The expression ability of the optimized gene in Pichia pastoris is obviously higher than that of the gene before optimization. An aiiaB546 M-containing recombinant expression plasmid is constructed; and recombination strains of the high-efficient homoserine lactonase can be obtained by introducing the recombinant expression plasmid into the Pichia pastoris. The expression ability of one of the recombination strains is particularly high. The DNA and the engineering bacteria have great value to the production of the homoserine lactonase.

The invention discloses N-acylhomoserine lactonase QsdA-RH5 with substrate specificity and a coding gene and application thereof. The protein QsdA-RH5 is (a) protein consisting of the amino acid sequences shown by sequence 1 in a sequence table, or (b) protein obtained by substituting and/or losing and/or adding one or multiple amino acid residues of the amino acid sequence of the sequence 1 in the sequence table, having the function of N-acylhomoserine lactonase and derived from the sequence 1 in the sequence table. Experiments prove that the QsdA-RH5 protein provided by the invention has substrate specificity and can degrade various N-acylhomoserine lactone without substituent groups; the specific activity of the QsdA-RH5 protein serving as N-acylhomoserine lactonase is 292.83U/mg and is stable in a pH range of 4.0-12.0, and more than 90% of enzyme activity can be maintained; and moreover, the thermal stability is better, and relative enzyme activity after keeping temperature at 70 DEG C for 10 minutes is still 100%. The QsdA-RH5 protein provided by the invention can be used for preparing a novel bio-control enzyme preparation.

The invention relates to N-acyl homoserine lactonase and a medicine thereof. An amino acid sequence of the N-acyl homoserine lactonase and a sequence as shown in SEQ ID NO.1 are at least 90% homologous, and the amino acid sequence of the N-acyl homoserine lactonase has N-acyl homoserine lactonase activity. The invention further provides a nucleotide sequence encoding the lactonase, an expression vector and a heterogenous expression strain. The medicine can treat (pseudomonas aeruginosa) infection. The N-acyl homoserine lactonase catalyzes lactone bonds of N-acyl homoserine lactone to hydrolyze, so that signal molecules between pseudomonas aeruginosa are quenched, and quorum sensing is interfered and inhibited. Compared with other N-acyl homoserine lactonase, the N-acyl homoserine lactonase has wider substrate adaptability and more efficient degradation activity and better effects when serving as the medicine for treating pseudomonas aeruginosa infection.

The invention relates to a method for performing secretory expression of glucose oxidase (GOD) based on the optimization of metabolic engineering, a recombinant bacterium and application thereof. The invention provides a method which can efficiently secretorily express GOD and improve the enzyme activity thereof. The GOD and malic acid dehydrogenase 1 coding gene (mdh1) or 6-phosphogluconolactonase coding gene (sol3) is co-expressed in a yeast strain, so that the efficient expression of the GOD is realized. Meanwhile, the invention also provides a recombinant bacterium for efficiently secreting the GOD built by adopting pichia pastoris as a host.

The invention relates to the cloning, sequencing and characterization of the gene responsible for Quorum Quenching (QQ) activity against Quorum Sensing (QS) signals of the Tenacibaculum sp. strain 20J (CECT7426). Said gene encodes a peptide having at least lactonase activity with a percentage of identity less than 38% with the lactonases described up until now for other species, as well as the sequences of the homologous genes present in other species of the genus Tenacibaculum. Said peptide shows a broad spectrum of activity degrading optionally substituted N-acyl-homoserine lactones (AHLs) of 4-14 carbon atoms in the side chain thereof, is active at pH comprised between 3 and 9, proteinase K- and chymotrypsin-resistant and does not interact with β-lactam antibiotics.

The present invention pertains to a new method for the diagnosis, prognosis, stratification and/or monitoring of a therapy, of cancer, preferably colorectal cancer (CRC), in a subject. The method is based on the determination of the level of a panel of least one, preferably 3, 4 and most preferably at least 5, protein biomarker selected from the group consisting of the protein biomarkers Amphiregulin (AREG), Carcinoembryonic antigen (CEA), Insulin like growth factor binding protein 2 (IGFBP2), Keratin, type I cytoskeletal 19 (KRT19), Mannan binding lectin serine protease 1 (MASP1), Osteopontin (OPN), Serum paraoxonase lactonase 3 (PON3) and Transferrin receptor protein 1 (TR), in the biological sample obtained from the subject. The new biomarker panel of the invention allows diagnosing and even stratifying various cancer diseases. Furthermore, provided are diagnostic kits for performing the non-invasive methods of the invention. Since the biomarker panel of the invention provides a statistically robust method independent of the protein detection technology used, and considering that the biomarker panel of the invention is detected in plasma samples of the subjects, the invention provides an early detection screening examination that may be applied to a larger population.

The present disclosure relates to an enzyme derived from Candida bombicola that is capable of lactonizing or polymerizing carbohydrate-containing compounds, lipids, fatty acids, hydroxylated fatty acids, alcohols, dicarboxylic acids or mixtures thereof. Hence, host cells comprising the latter enzyme can be used, via the formation of intra- or inter-molecular ester-bounds, to produce, for example, lactonized sophorolipids or polymers of acidic sophorolipids. On the other hand, host cells having lost their capability to produce a functional enzyme disclosed herein can be used to produce 100% acidic sophorolipids.

The invention provides a novel feed additive for improving the intestinal health index of broiler chickens and application thereof, the active ingredients of the feed additive are N-acyl homoserine lactonase and lactic acid bacteria, and the N-acyl homoserine lactonase and lactic acid bacteria can synergistically inhibit the reproduction of harmful bacteria. Broiler chicken breeding tests show that N-acyl homoserine lactonase and lactic acid bacteria have a synergistic effect, and the additive can improve the intestinal villus height of broiler chickens, reduce the overall inflammatory response of intestinal tracts, obviously reduce intestinal bleeding points of the broiler chickens and improve the health condition of the intestinal tracts, so that the survival rate and production performance of the broiler chickens are improved.

The invention provides recombinant clostridium acetobutylicum for efficiently converting a straw biomass carbon source as well as a construction method and application of the recombinant clostridium acetobutylicum. The recombinant clostridium acetobutylicum for efficiently converting the straw biomass carbon source is a clostridium acetobutylicum strain which is over-expressed by clostridium acetobutylicum xylose transporter protein, caulobacter crescentus xylose dehydrogenase and xylose lactonase in a synergistic manner. Specifically, the recombinant clostridium acetobutylicum is clostridiumacetobutylicum TXYL and was preserved in China Center for Type Culture Collection on May 8th 2020, and the preservation number of the strain is CCTCC NO: M 2020107. The recombinant clostridium acetobutylicum for efficiently converting the straw biomass carbon source is applied to fermentation of straw hydrolysate to produce butanol, the fermentation period is shortened to 24 hours, the consumptionrate of glucose and xylose is increased, the utilization rate of the xylose is increased, efficient conversion of straw glucose and xylose carbon sources is realized, and the yield of the butanol andthe production intensity are remarkably improved.

The invention relates to a triple-PCR (polymerase chain reaction) detection kit for macrolide drug resistance genes of staphylococcus infecting livestock. The kit comprises three pairs of PCR primers for amplifying drug resistance genes of to-be-detected bacteria, a template preparation reagent and a bacterial drug resistance gene multiple-amplification reagent. Compared with a conventional drug sensitive test, the multiple-type method has the advantages that the detection time is shortened from days to one day. Pathogenic bacteria often contain multiple macrocyclic lactonase genes. The technology meets the demands for detecting multiple genes simultaneously, and the detection accuracy and specificity are improved; the technology can be used for detecting three macrolide type drug resistance genes in clinical bacteria isolates.

The invention relates to a method for solvent system free enzymic synthesis of anti oxidant, namely, ferulic acid bis-butanoic acid glyceride. The method comprises the following steps: firstly, being catalyzed by thionyl chloride, ferulic acid and absolute ethyl alcohol are heated under reflux and reaction, are dissolved in ethylether, and are extracted by sodium bicarbonate, the ethylether is removed, and then standstill and seed out are performed to obtain ferulic acid ethyl ester which is then purified; secondly, by utilizing the characteristic that glycerol monobutyralte is liquid at room temperature, the obtained ferulic acid ethyl ester and the glycerol monobutyralte are directly used as the reaction medium and the substrate, and are reacted in the catalysis of Novozym435 lipase and purified, thereby obtaining the ferulic acid bis-butanoic acid glyceride. The method has mild and safe reaction condition, and prepared oxidant which maintains the property of the ferulic acid and the butanoic acid is released slowly under the function of lactonase in the human body. The method has the functions of being anti-oxidation and anti-fatigue, and removing harmful free radical in the human body, and also has the functions of preventing and treating various cardiovascular and cerebrovascular diseases. The method does not use organic solvent, thus simple post treatment is ensured and the environmental pollution is reduced.

The invention discloses a bacillus velezensis YtnP-homologous lactonase, a gene and application thereof. The invention firstly discloses the bacillus velezensis YtnP-homologous lactonase, wherein the amino acid sequence of the bacillus velezensis YtnP-homologous lactonase is shown as SEQ ID NO.1. The invention further discloses the application of the bacillus velezensis YtnP-homologous lactonase in the treatment of dental chair type equipment. The disclosed bacillus velezensis YtnP-homologous lactonase can be used for remarkably inhibiting early proliferation, biofilm formation and virulence factor release of pseudomonas aeruginosa, is an effective way for reducing opportunistic pathogenic bacterium infection, and can be used as a novel dental hygiene treatment disinfectant.

Provided herein are lactonases. In one embodiment, the lactonases are metallo-β-lactamase-like lactonase (MLL) enzymes having altered characteristics such as altered catalytic activity and/or altered substrate specificity. Also provided are genetically modified microbes able to express a MLL enzyme, compositions that include a MLL enzyme, and methods of using a MLL enzyme.