31 results about "Citrobacter freundii" patented technology

The invention discloses a urease-producing microorganism induced calcium carbonate deposition solution for foundation reinforcement and a preparation method and application thereof, and belongs to the technical field of foundation reinforcement. The urease-producing microorganism induced calcium carbonate deposition solution comprises a bacterial solution, a cementing solution and a sodium citrate solution, the bacterial liquid comprises bacteria capable of generating urease and citrobacter freundii. Sodium citrate in the urease-producing microorganism induced calcium carbonate deposition solution can chelate free calcium ions in advance, the concentration of the free calcium ions is reduced, the risk of precipitation at an injection port in the single-phase injection process is eliminated, and the solution can smoothly permeate into a deep layer; citrobacter freundii produces acid through metabolism and utilizes citric acid radicals through metabolism to ensure gradual release of calcium ions, so that uniform deposition of calcium carbonate is triggered. Through the synergistic effect of sodium citrate chelated calcium ions and citrobacter freundii metabolism, the solution can be uniformly distributed in the soil sample, and the problem of uniformity of single-phase perfusion is successfully solved.

The invention discloses an application of engineered citrobacter freundii in fermentation synthesis of a stable body. The engineered citrobacter freundii is citrobacter freundii overexpressing a polyphosphate kinase gene Ppk1. The stable body prepared by fermenting the engineered citrobacter freundii is rich in polyphosphates and polyamines, particularly, the content of the polyamines can be up to 21wt%, the polyphosphates in the stable body can store the polyamines in an ionic bond combination mode, the combined polyamines are insoluble in water, a natural anion coating is generated, and the stability of the stable body is improved. And the sustained-release tablet is not easily taken by intestinal epithelial cells, so that the sustained-release tablet has a certain sustained-release effect. The medicine prepared by taking the compound as a main active ingredient shows a remarkable curative effect in ulcerative colitis treatment, has the comprehensive effects of reducing oxidative stress, enhancing the anti-inflammatory ability of a body and regulating immunity, is suitable for patients of all ages, and has outstanding application value and market prospect.

The invention relates to the technical field of microorganisms, in particular to a citrobacter freundii phage and application thereof. The citrobacter freundii phage is a citrobacter freundii phage CFP7ACFGC5 (Citrobacter freundii phage CFP7ACFGC5), the citrobacter freundii phage CFP7ACFGC5 is preserved in the China Center for Type Culture Collection on July 21, 2025, and the number of the citrobacter freundii phage CFP7ACFGC5 is CCTCC (China Center for Type Culture Collection) NO: M20251640. The bacteriophage has a relatively broad-spectrum host range, and can still keep relatively high activity while splitting target bacteria; meanwhile, the bacteriophage is excellent in acid resistance and thermal stability, can meet the application requirements of multiple temperature nodes in production, and has a good application prospect.

The invention provides a citrobacter freundii phage and an application thereof. The bacteriophage is a citrobacter freundii bacteriophage CFP2505001, and the preservation number is CCTCC (China Center For Type Culture Collection) NO: M20251306. The bacteriophage has excellent lysis activity, thermal stability and pH stability, can efficiently perform targeted lysis on multi-drug-resistant citrobacter freundii, significantly reduces the infection death rate of Japanese eels, and provides a new microbial resource and application approach for green prevention and control of citrobacter freundii diseases in aquaculture.

This invention belongs to the field of microbial technology and discloses a strain of *Citrobacter freundii* bacteriophage PRF337, its bacteriophage composition, and its applications. The *Citrobacter freundii* bacteriophage PRF337 was deposited on May 26, 2025, at the China General Microbiological Culture Collection Center (CGMCC), located at No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, with accession number CGMCC No. 46489. The bacteriophage PRF337 exhibits broad-spectrum bactericidal activity against *Citrobacter freundii*, capable of lysing *Citrobacter freundii* strains containing different virulence genes and from different sources. It also possesses certain temperature and pH stability and can be used as an active ingredient in pharmaceutical preparations, environmental disinfectants, and water purifiers. It can effectively control *Citrobacter freundii* infection in aquatic animals such as fish and shrimp in aquaculture environments and can also be used for the purification of pathogens in aquatic environments. It is safe to use and effectively avoids the problems of antibiotic residues and pathogen resistance caused by antibiotic use.

The application provides a chromium-contaminated laterite soil repairing agent and a repairing method thereof, and the method realizes effective repair of the laterite soil through the steps of pretreating the soil, applying the repairing agent I and applying an electric field, adding the repairing agent II for maintenance, and finally connecting biological strains.The method comprises the following steps: removing sundries, plowing the soil, applying the repairing agent I containing a reducing agent, citric acid and other components, and treating under specific electric field conditions.Subsequently, the repairing agent II, such as organic fertilizer, iron oxide, nano zeolite and chitosan derivative, is added.Finally, specific proportions of aspergillus, citrobacter freundii and psychrobacter are connected for biological repair.The method comprehensively considers physical, chemical and biological repair means, aims to efficiently remove chromium pollution in the soil, improve the soil organic carbon content of the laterite soil, and restore the ecological function of the soil.

This invention discloses the application of engineered *Citrobacter freundii* in the fermentation synthesis of spermine. The engineered *Citrobacter freundii* is a strain overexpressing the polyphosphate kinase gene Ppk1. The engineered *Citrobacter freundii* is inoculated into a fermentation medium for fermentation culture to synthesize spermine. The synthesis and extraction method of this invention for producing spermine is simple to operate, highly reproducible, low in cost, and yields a high spermine content in the fermented bacterial cells, accounting for 12.42% of the bacterial dry weight. The extracted spermine has a purity as high as 90.26%.

The invention belongs to the technical field of gene engineering and enzyme engineering, and aims to provide a tyrosine phenol lyase mutant which is higher in catalytic efficiency and more suitable for industrial production of levodopa and is derived from citrobacter freundii, and compared with a wild tyrosine phenol lyase type, the tyrosine phenol lyase mutant has T49R or / and M379R mutation; the amino acid sequence of the tyrosine phenol lyase wild type is shown as SEQ ID NO.2 in a sequence table. The mutant and the engineering strain provided by the invention have the huge advantages of high catalytic efficiency and high product yield.

The invention discloses a 1, 3-propylene glycol production strain capable of weakening by-product accumulation and a construction method, and relates to the technical field of biology, the production strain takes a natural or artificially modified strain capable of utilizing glycerol to synthesize 1, 3-propylene glycol as an original strain, and the original strain is a natural or artificially modified strain capable of utilizing glycerol to synthesize 1, 3-propylene glycol. At least one functional gene related to glycerol oxidation or by-product generation is inactivated through gene editing technology transformation, and at least one key gene related to 1, 3-propylene glycol reduction synthesis is expressed at a high level; the starting strain is at least one of klebsiella or citrobacter freundii or at least one of artificially modified strains; according to the invention, genes such as dhaD, ldhA, pta / ackA, adhE, budA / B / C (by-product synthesis pathway) and the like are knocked out directionally through a CRISPR / Cas9 technology, so that the generation of by-products such as lactic acid, acetic acid, ethanol, 2, 3-butanediol and the like is effectively blocked. The carbon source and reduction equivalent (NADH) of the modified strain are not shunted to by-product synthesis any more, and are more used for 1, 3-propylene glycol generation, so that the problem of carbon source waste of the traditional strain is solved.

Provided are Citrobacter freundii and the use thereof. The Citrobacter freundii has a high cadmium tolerance and the function of enhancing selenium bioavailability. The strain is classified as and named Citrobacter freundii DS, which has been deposited in the CCTCC on 26 May 2022. The strain has a high tolerance to the heavy metal cadmium. The strain can still grow under the conditions of a Cd2+ concentration of 6 mM, reaching the maximum biomass at 40 h. By means of applying the strain to cadmium-contaminated soil, the proportion of exchangeable cadmium and the content of available cadmium in the soil can be significantly decreased, while significantly increasing the content of soluble selenium and available selenium in the soil. By means of performing a rice pot experiment, the cadmium bioaccumulation factor in various parts of rice is further reduced, while increasing the selenium bioaccumulation factor and translocation factor. The strain has significant effects in the applications of remediating cadmium-contaminated soil, enhancing the bioavailability of selenium and promoting crop growth.

The invention relates to the fields of gene engineering, enzyme engineering and bioinformatics, and particularly discloses application of glycine free radical enzyme in preparation of propylene glycol. Transforming a glycolytic pathway of escherichia coli: knocking out phosphofructokinase, acetaldehyde dehydrogenase, lactic dehydrogenase and ethanol dehydrogenase of the strain; according to the present invention, the following genes driven by the strong promoter, such as glycerol dehydrogenase, fructose-6-phosphate aldolase, mannitol-1-phosphate dehydrogenase, and dihydroxyacetone kinase, glycine free radical enzyme and free radical activating enzyme of citrobacter freundii, are integrated in the genome so as to enhance the metabolic pathway for synthesizing 1, 2-propylene glycol, and finally obtain the genetically engineered bacterium, wherein the genes comprise glycerol dehydrogenase, fructose-6-phosphate aldolase, mannitol-1-phosphate dehydrogenase, dihydroxyacetone kinase, glycine free radical enzyme and free radical activating enzyme of citrobacter freundii. The R-1, 2-propylene glycol produced by using the genetically engineered bacterium through a biological method can be applied to the fields of medicines, cosmetics, foods and the like, and high-added-value products are developed to meet the requirements of different fields on the R-1, 2-propylene glycol.

This invention relates to the field of microbial technology, and more particularly to a broad-spectrum Aeromonas hydrophila phage and its applications. The Aeromonas hydrophila phage AhP2505006 is classified as follows: Aeromonas hydrophila Phage AhP2505006, with accession number CCTCC NO: M20251307, exhibits cross-species lytic activity. It can effectively lyse *Aeromonas*, *Vibrio parahaemolyticus* and *Vibrio alginolyticus*, and *Citrobacter freundii*. It also possesses excellent targeting ability against multidrug-resistant strains and broad host spectrum characteristics, achieving a lysis rate of up to 80% against multidrug-resistant *Aeromonas hydrophila*. In the prevention and control of diseases caused by various pathogens, or in practical scenarios facing the limitations of traditional antibiotics and highly specific bacteriophages, it has become a highly promising solution.

The invention discloses an application of engineered citrobacter freundii in fermentation synthesis of spermine, the engineered citrobacter freundii is citrobacter freundii overexpressing a polyphosphate kinase gene Ppk1, and the engineered citrobacter freundii is inoculated into a fermentation medium for fermentation culture to synthesize spermine. The synthesis and extraction method for producing spermine is simple to operate, high in repeatability and low in cost, the spermine content in thalli obtained through fermentation is high and accounts for 12.42% of the dry weight of bacteria, and the purity of the extracted spermine is as high as 90.26%.

Described herein are compositions, methods, and kits for detecting wound pathogens. One embodiment described herein is primer pairs and probes for individual, simultaneous, or sequential multiplex polymerase chain reaction (PCR) based assays for the detection of Acinetobacter baumannii, Bacteroides fragilis, Clostridium perfringens, Enterobacter cloacae, Enterococcus faecalis, Enterococcus faecium, Escherichia coli, Klebsiella pneumoniae, Klebsiella Oxytoca, Klebsiella aerogenes, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus pyogenes, Streptococcus anginosus, Staphylococcus lugdunensis, Providencia stuartii, Stenotrophomonas maltophilia, Morganella morganii, Citrobacter koseri, Citrobacter freundii, Citrobacter braakii, Peptoniphilus asaccharolyticus, Peptoniphilus harei, Peptoniphilus ivorii, Peptostreptococcus anaerobius, Finegoldia magna, Clostridium septicum, Paeniclostridium sordellii (Clostridium sordellii), Clostridium novyi A, B, Clostridium histolyticum, Staphylococcus epidermidis, Staphylococcus haemolyticus, Corynebacterium striatum, Candida albicans, Candida auris, Candida glabrata, Candida krusei, Candida parapsilosis, or Candida tropicalis.

The invention discloses a composition, a kit and a detection method for detecting bacterial infection pathogens. The composition comprises at least one of a component A, a component B and a component C, the component A comprises nucleotide sequences as shown in SEQ ID NO: 1-3, and the component A is used for detecting bacteroides fragilis; the component B comprises nucleotide sequences as shown in SEQ ID NO: 4-6, and the component B is used for detecting citrobacter freundii; the component C comprises nucleotide sequences as shown in SEQ ID NO: 7-9, and the component C is used for detecting enterobacter aerogenes. By designing the upstream and downstream primers and the corresponding probes, the composition for detecting the bacterial infection pathogens can detect and distinguish at least one of bacteroides fragilis, citrobacter freundii and enterobacter aerogenes, is high in sensitivity, high in specificity and strong in anti-interference performance, improves the detection efficiency, shortens the detection period, reduces the detection cost, and is suitable for popularization and application. Good application prospects are realized.

The application belongs to the technical field of microorganisms, and particularly relates to a Citrobacter freundii BD11 with anaerobic CO2 fixation function and application of the Citrobacter freundii BD11 in synthesis of cationic polysaccharide. The Citrobacter freundii BD11 is preserved in the China General Microbiological Culture Collection Center on July 6, 2026, and the preservation number is CGMCC No. 38727. The Citrobacter freundii BD11 is a gram-negative facultative anaerobe, can synthesize cationic polysaccharide by using CO2 and acetate under anaerobic conditions, and the CO2 fixation amount is 41-45 mM within 21 days, so that the resource utilization of CO2 is realized, and the green biological manufacturing concept is met. The synthesized cationic polysaccharide is a heteropolysaccharide structure, the monosaccharide composition and relative content are as follows: 70-75% of glucosamine, 17-20% of galactosamine, and 8-10% of mannose. In addition, the cationic polysaccharide also has high efficient bacteriostatic activity, when the concentration of the cationic polysaccharide is greater than or equal to 0.2%, the inhibition rate on Escherichia coli K-12 is greater than or equal to 90% within 1 h.

The invention discloses citrobacter fabricius and application of the citrobacter fabricius in improvement of compost fertilizer efficiency of tung tree fruits, the citrobacter fabricius CDC 2991-81 has been preserved in Guangdong Microbial Culture Collection Center on September 29, 2025, the preservation number is GDMCC No: 67054, and the classification number is citrobacter fabricius (Citrobacter fabricius). By adding the citrobacter fabricius into the tung tree fruit compost, the content of fatty acid in the tung tree fruit compost can be remarkably reduced, the content of ammonium nitrogen, nitrate nitrogen, phosphorus and potassium is increased, and the composting effect of tung tree fruits is remarkably improved. The invention provides a new microbial approach for the utilization of tung tree fruit compost.

The invention discloses citrobacter sp. And application thereof in soybean planting, and belongs to the technical field of biological agriculture. The citrobacter sp. NJC42 is preserved in the China Center for Type Culture Collection, the preservation number of the citrobacter sp. NJC42 is CCTCC No.M 20242057, and the preservation date of the citrobacter sp. NJC42 is September 24, 2024. The citrobacter sp. NJC42 disclosed by the invention not only can inhibit the growth of Xanthomonas axonophora pv.glycines, is used for preparing a preparation for preventing soybean bacterial leaf spot, but also can be used for promoting the yield increase of soybeans, and is used for preparing a preparation for promoting the yield increase of the soybeans, so that the citrobacter sp. NJC42 disclosed by the invention can be used for inhibiting the growth of the Xanthomonas axonophora pv.glycines, and the citrobacter sp. NJC42 disclosed by the invention can be used for preparing a preparation for promoting the yield increase of the soybeans.

The application relates to the technical field of biological detection, and particularly relates to the application of a primer, a probe or a kit targeting an effector proteinhcp gene of a T6SS of Citrobacter freundii, wherein the application first designs specific primers (SEQ ID NO: 1-2) and a probe (SEQ ID NO: 3) aiming at thehcp gene of the effector protein of the T6SS of the Citrobacter freundii, the target gene of the application has higher pathogenicity correlation, and the detection specificity is significantly improved. The application combines recombinase polymerase amplification (RPA) with a lateral flow immunochromatographic test strip (LFD), and realizes integration of "amplification-detection". The method only needs one pair of primers, and amplification can be completed at normal temperature (38 DEG C) for 20-30 minutes; combined with the LFD test strip, the result can be judged by naked eyes for 3-5 minutes, and no precise instrument is needed in the whole process, and the detection result is objective and reliable.

The invention provides a primer probe pair for detecting an enterobacter cloacae complex, a composition, a kit and application, and relates to the technical field of biology. The primer probe pair for detecting the enterobacter cloacae complex comprises a primer probe pair with the nucleotide sequence shown as SEQ ID NO.1-3, a primer probe pair with the nucleotide sequence shown as SEQ ID NO.4-6 or a primer probe pair with the nucleotide sequence shown as SEQ ID NO.7-9; the primer probe composition further comprises a primer probe pair used for detecting serratia marcescens and a primer probe pair used for detecting citrobacter freudensis. The primer probe composition can be used for simply, quickly and accurately detecting the enterobacter cloacae complex, the serratia marcescens and the citrobacter freurauensis.

The present application relates to the field of microbial technology, and more particularly to a high-temperature-resistant and titer-stable Citrobacter freundii bacteriophage and its application. The present application discloses a high-temperature-resistant and titer-stable Citrobacter freundii bacteriophage, named RDP-CI25004, and provides a powder thereof and its application. The bacteriophage has good lytic activity on Citrobacter freundii, maintains stable biological performance in a wide temperature and pH range, and can resist high-temperature treatment of 80-90 ℃. After the bacteriophage is spray-dried into a powder, the titer remains stable during long-term storage at room temperature, significantly improving the problem that the titer of the existing bacteriophage easily decreases during high-temperature processing and storage. The bacteriophage and the powder thereof are suitable for the prevention and control of Citrobacter freundii, and have good application prospect and industrial value.

The invention relates to a primer and probe combination for simultaneously detecting urinary tract klebsiella pneumoniae and drug-resistant genes through nested PCR (Polymerase Chain Reaction) and a kit of the primer and probe combination, which can solve the problem that the existing detection target lpxC of klebsiella pneumoniae is highly homologous with the sequence alignment of part of related bacteria (klebsiella oxytoca, enterobacter aerogenes and citrobacter freundii); based on the defect that a primer and probe combination designed by an existing target lpxC causes cross amplification of the bacteria and does not meet clinical requirements, and the situation that a combination of a drug-resistant gene mecA and klebsiella pneumoniae is not suitable for clinical scenes, by simultaneously identifying the klebsiella pneumoniae and common drug-resistant genes of the two bacteria, the drug-resistant genes of the two bacteria can be identified, and the drug-resistant genes of the two bacteria can be identified. The Klebsiella pneumoniae gene, namely a carbapenemase-producing drug-resistant gene KPC-2 and an extended-spectrum beta-lactamase-producing drug-resistant gene (ESBL) CTX-M-15, can be used for judging whether the Klebsiella pneumoniae is sensitive or drug-resistant Klebsiella pneumoniae and distinguishing specific drug-resistant phenotypes, so that more comprehensive and definite medication guidance can be provided for clinicians.

The invention relates to the technical field of biological detection, in particular to application of a primer, a probe or a kit for targeting a citrobacter freundii T6SS effect protein hcp gene, the specific primer (SEQ ID NO: 1-2) and the probe (SEQ ID NO: 3) are designed for the hcp gene of the citrobacter freundii T6SS effect protein for the first time, the target gene has higher pathogenicity, the specificity is high, and the specificity is high. The detection specificity is obviously improved. According to the invention, recombinase polymerase amplification (RPA) and a lateral flow immunochromatography test strip (LFD) are combined for use, so that integration of amplification and detection is realized. According to the method, only one pair of primers is needed, amplification can be completed by reacting for 20-30 minutes at normal temperature (38 DEG C), the result is interpreted by naked eyes for 3-5 minutes in combination with an LFD test strip, precise instruments are not needed in the whole process, and the detection result is objective and reliable.

The invention discloses citrobacter freundii, a product and application, and belongs to the technical field of microorganisms. The preservation number of the citrobacter freundii is CGMCC (China General Microbiological Culture Collection Center) No.36707, and the preservation number of the citrobacter freundii is CGMCC The strain not only meets the basic biological safety requirement, but also can efficiently and specifically activate a key cGAS-STING innate immune signal channel in a host cell by virtue of a culture supernatant, so that the expression levels of the type I interferon and a downstream effect gene thereof are remarkably up-regulated. Due to the unique immunoregulation function, the compound shows a good inhibition effect on replication of herpes simplex virus and vesicular stomatitis virus, and a new resource and a feasible path are provided for developing an antiviral biological preparation which is based on flora immunoregulation and has broad-spectrum potential.

The application provides a composition of multiplex PCR primers and probes for detecting microorganisms, a kit and a method thereof. The composition comprises 10 pairs of primers for staphylococcus aureus, salmonella, pseudomonas aeruginosa, clostridium tetani, citrobacter freundii, streptobacterium maltophilia, burkholderia cepacia, klebsiella pneumoniae, candida albicans and escherichia coli, and 10 corresponding probes, wherein the 10 pairs of primers are shown as SEQ ID No. 1-20, and the 10 probes are shown as SEQ ID No. 21-30. The composition of primers and probes of the application is used for multiplex PCR for detecting microorganisms, is simple to operate, and has high detection accuracy.

This invention relates to a peptide and its application in the preparation of antibacterial drugs, belonging to the field of peptide technology. The amino acid sequence of the staple peptide of this invention is G(S5)IAG(S5)IIKIKK-NH2. This includes two S5 residues cyclized to form the staple peptide. The staple peptide of this invention exhibits bioactivity against various carbapenem-resistant Gram-negative bacteria, such as *Citrobacter freundii*, *Pseudomonas aeruginosa*, *Klebsiella pneumoniae*, *Enterobacter cloacae*, *Klebsiella pneumoniae*, and *Escherichia coli*. The staple peptide sp3 kills bacteria by inducing bacterial cell membrane potential dissipation and triggering reactive oxygen species accumulation. Furthermore, sp3 exhibits good stability in trypsin, is not easily degraded, and possesses low cytotoxicity. In summary, the staple peptide sp3 has promising applications and potential in the pharmaceutical field and can serve as a candidate molecule for novel antibacterial drugs.

The invention relates to a suitable citrobacter strain and application thereof. The invention relates to citrobacter suitabilis strain J35, which is preserved in the China General Microbiological Culture Collection Center (CGMCC), the preservation number of the citrobacter suitabilis strain J35 is CGMCC No.36708, and the citrobacter suitabilis strain J35 has insecticidal activity on Sitobion avenae, Rhopalosiphum padi, Amyzus persicae, Lygocoris lucorum, Bemisia tabaci, Plutella xylostella and Spodoptera litura. The citrobacter suitabilis strain J35 has the advantages that the strain J35 is preserved in the China General Microbiological Culture Collection Center (CGMCC), and the preservation number of the citrobacter suitabilis strain J35 is CGMCC

The invention discloses citrobacter freundii and application thereof, the citrobacter freundii is excellent in performance and capable of producing hyaluronidase at high yield, and the obtained hyaluronidase is high in enzyme activity and excellent in performance and has wide application prospects.

The application discloses an engineering bacterium for synthesizing PHA by using carbon dioxide and a construction method and application thereof. First, the Rubisco gene from Methanosaeta sp. GP6 is integrated on the genome, and the original promoter is replaced; then, the hydrogenase gene from Citrobacter freundii ATCC 29220 is integrated on the genome, the lactate dehydrogenase gene in the competitive pathway is knocked out, and the PHA synthesis gene is overexpressed, so as to further improve the PHA yield. The engineering bacterium provided by the application adopts a high-density fermentation culture method, the PHA yield in a 5L fermenter can reach 83.5% of the cell dry weight, and the cell dry weight reaches 22.14g / L. The application has important application significance for industrialized production of PHA.

The application discloses application of genetically engineered bacteria in preparation of a preparation for treating multiple myeloma or relapsed refractory multiple myeloma. The genetically engineered bacteria are Citrobacter freundii with deaminase related gene mutation; the deaminase related mutant gene is imine / enamine deaminase gene and adenosine deaminase gene. The application introduces an expression vector of imine / enamine deaminase mutant gene or adenosine deaminase mutant gene, carries out homologous recombination in the Citrobacter freundii, replaces the wild type imine / enamine deaminase gene or wild type adenosine deaminase gene with the imine / enamine deaminase mutant gene or adenosine deaminase mutant gene, realizes reduction of NH4 + , and obtains genetically engineered bacteria with reduced NH4 + product. The application provides a new treatment strategy for clinically treating relapsed refractory multiple myeloma, and enriches existing neoadjuvant therapy.