289 results about "Aflatoxin B" patented technology

The present invention belongs to the field of biological detection. Multi-line immunochromatographic test strip for semi-quantitative detection of aflatoxin B₁ comprises a paperboard, wherein a water-absorbing pad, a detection pad, a gold-labeled pad and a sample pad are adhered sequentially on one surface of the paperboard from top to bottom, wherein each adjacent pads is overlapped and connected, the detection pad uses a nitrocellulose film as a backing pad, the nitrocellulose film is provided with a transverse control line, a test line I, a test line II and a test line III, wherein the control line is coated with a rabbit anti-mouse polyclonal antibody, and the test line I, test line II and test line III are coated with aflatoxin B₁-bovine serum albumin conjugate (AFB₁-BSA), respectively: and the gold-labeled pad is transversely coated with a nanogold-labeled anti-aflatoxin B₁ monoclonal antibody. Said test strip is used for semi-quantitative detection of aflatoxin B₁, and is characterized by quick detection, simple procedure and high sensitivity.

The invention relates to an aflatoxin B1 flow lag immunization time distinguishing fluorescence rapid-detection kit and an application thereof. The kit comprises a fluorescent test strip and a sample reaction bottle containing an europium-labeled anti-aflatoxin B1 monoclonal antibody lyophilized product, wherein the fluorescent test strip comprises a cardboard, a water absorption pad, a detection pad and a sample pad are sequentially pasted on one surface of the cardboard from top to bottom, adjacent pads are connected at the connection in an overlapping manner, the detection pad treats a cellulose nitrate membrane as a base pad, a transverse quality control line and a detection line are arranged on the cellulose nitrate membrane from top to bottom, the quality control line is coated with a rabbit anti-mouse polyclonal antibody, and the detection line is coated with an aflatoxin B1 bovine serum albumin conjugate; and the anti-aflatoxin B1 monoclonal antibody is secreted by a hybridoma cell strain having a preservation number of CCTCC NO.C201015. The kit can be used for the quantitative determination of the content of the aflatoxin B1, and has the advantages of simple operation, rapidness and high accuracy.

The invention discloses a method for degrading aflatoxin, which makes use of gamma rays to irradiate a sample containing the aflatoxin, wherein the gamma rays are generated by a radioactive substance Co, and the irradiation dose is between 0 and 10 kGy not including 0, preferably between 2 and 10 kGy, more preferably between 4 and 10 kGy, particularly preferably between 6 and 10 kGy, and the most preferably 10 kGy. The sample containing the aflatoxin is a farm product containing the aflatoxin or a product obtained by processing the farm product, such as food, feedstuff, and the like. The method is particularly applicable to degrading the aflatoxin B1, not only can kill pathogenic microorganisms but also can degrade biotoxin therein, and does not generate any industrial pollution.

The invention discloses a complex microbial agent for producing soybean paste in Pixian County, which mainly comprises coculture of saccharomyces cerevisiae, candida utilis, lactobacillus plantarum and salt tolerant tetrads, and skim milk powder, glycerin, maltodextrin, trehalose and L-sodium glutamate, or mainly comprises coculture of saccharomyces cerevisiae, candida utilis, lactobacillus plantarum and salt tolerant tetrads, and porous starch, maltodextrin and polyvinyl pyrrolidone. A method for preparing the complex microbial agent for producing soybean paste in Pixian County comprises the following technological steps of: (1) activating and propagating strains; (2) inoculating; (3) co-culturing; and (4) adding a protective agent and drying. By using the complex microbial agent in the preparation of cooked soybean paste, the complex microbial agent maintains the characteristics of traditional soybean paste in Pixian County. Meanwhile, compared with the traditional technology, the complex microbial agent has the advantages of shortening the production period by 1/3, improving the amino nitrogen content by 3 to 8 times, improving the volatile aroma content by 2 to 4 times, and ensuring the aflatoxin B1 of 0 to 0.5ppm only.

The present invention is fast detection method of aflatoxin B1 in food and feed. The fast detection method includes the following steps: adding ground sample to be tested in 2-10 g in test tube, adding methanol-sodium chloride aqua of 50-80 % concentration in 10-25 ml, ultrasonic extraction in water bath at 40-60 deg.c, and suction filtering to obtain filtrate in 4-10 ml; adding re-distilled petroleum ether in 2-4 ml into the filtrate, shaking, letting stand to laminate, taking the lower layer of solution in 1-4 ml and adding pure water in 4-20 ml; adding to micro immunoaffinity column of aflatoxin B1, washing with methanol aqua of 10-40 % concentration in 5-10 ml, eluting with methanol in 0.5-2.0 ml, collecting the eluted liquid, adding test agent A in 0.2-1.0 ml; and detecting in fluorescent spectrophotometry or similar instrument. The present invention has the features of simple process, high detection precision and stability, fast detection speed and high safety.

The invention provides an aflatoxin B1 (AFB1) magnetic separation enzyme-linked immunity quantitative detection method, belonging to the field of food safety immunoassay technique. The method adopts the immuno-detection principle of competition law; and AFB1 is connected with biological enzyme to prepare enzyme-labeled antigen reagent, anti-fluorescein isothiocyanate (FITC) antibody is absorbed onthe surfaces of magnetic particles to prepare magnetic separation reagent, and the FITC is connected with the AFB1 antibody to prepare anti-reagent. In a sample, the AFB1 competes with the enzyme-labeled AFB1 and is combined with a small amount of FITC-labeled anti-AFB1 antibody, so that antigen-antibody complex can be formed. After the magnetic separation reagent is added, the complex is caughtonto the surfaces of the magnetic particles by the anti-FITC antibody connected on the surfaces of the magnetic particles. After being washed, the product is finally added with substrate and detected.The method has the advantages that (1) the magnetic particles are used for replacing the traditional enzyme-labeled plate to be taken as a solid-phase carrier, so that immunoreaction is carried out under the approximate liquid phase condition; and the reaction is more complete and rapid, and has the characteristics of high specificity and good repeatability compared with the traditional enzyme-linked immuno sorbent assay (ELISA); furthermore, (2) by adopting one-step competition law principle, the time used for detection is short.

The invention relates to the field of bioengineering, in particular to a preparation method and an application of a microbial agent composition for enhancing secondary fermentation of a bean paste. The microbial agent composition consists of a saccharomycetes agent, an aspergillus oryzae agent and a pleospora agent; and the three microbial agents are prepared, and then the prepared microbial agents are mixed with the secondary-fermented bean paste, so as to promote the secondary fermentation of the bean paste. The whole process of the preparation method of the microbial agent composition provided by the invention is applicable to continuous industrial production; by-products (chili and radix platycodonis), from the production of Pixian bean paste, are comprehensively utilized; a production cycle can be shortened by 6 months, the content of amino nitrogen can be improved by 20% and the content of volatile aroma-producing components can be improved by more than 3 times (the contents of total ester, total acid and total aldehyde); by inoculating aflatoxin B1 with the saccharomycetes agent at a production peak (after being fermented for 30-60 days), an ester producing and aroma generating process can be enhanced, the metabolism of aspergillus flavus and partial aspergillus parasiticus can be competitively inhibited and the content of the aflatoxin B1 can be reduced, and the content of the aflatoxin B1 is lower than 0.5ppm, so that food safety is enhanced.

The present invention relates to a hybridoma cell line 3G1 and an anti-alfatoxin B1 monoclonal antibody produced by the hybridoma cell line 3G1. The hybridoma cell line 3G1 (CCTCCNO.C201014) can be used for preparation of a high titer anti-aflatoxin B1 monoclonal antibody, wherein an enzyme-linked immunosorbent assay (ELISA) method is adopted to determine a titer, and the titer is 6.40*10<6>. The anti-aflatoxin B1 monoclonal antibody of the present invention has characteristics of high sensitivity and good specificity, wherein 50% inhibiting concentration on aflatoxin B1 by the monoclonal antibody is 1.6 ng/mL, cross reaction rate with aflatoxin B2 is 6.4%, and cross reaction rates with aflatoxin G1 and G2 are less than 1%. In addition, the anti-aflatoxin B1 monoclonal antibody of the present invention can be used for determination of aflatoxin B1.

The invention discloses a test strip for detecting aflatoxin B1 or M1 by utilizing an aptamer. The test strip for detecting the aflatoxin B1 or M1 by utilizing the aptamer, provided by the invention, comprises a sample absorption pad, a marker pad, a reaction film and a water absorption pad, wherein the marker pad is coated with a detection probe; the detection probe is an aflatoxin B1 aptamer marked by fluorescein; the nucleotide sequence of the aflatoxin B1 aptamer is sequence 1; the reaction film comprises a detection region and a quality control region; the detection region is coated with a conjugate formed by an aflatoxin B1 hapten and a carrier protein; and the quality control region is coated with a quality control probe, and the quality control probe is a conjugate formed by avidin conjugation probe marked aflatoxin B1 complementary single strand DNA (Deoxyribose Nucleic Acid)) molecules. The test strip for detecting the aflatoxin B1 or M1, provided by the invention, has the advantages of high sensitivity, accuracy in quantifying, strong specificity, simplicity and convenience, and short detection time.

The invention discloses a bacillus amyloliquefacien for degrading aflatoxin B1 in peanut meal, and belongs to the technical field of applied microbiology. According to the invention, a bacillus amyloliquefacien capable of significantly inhibiting the growth of Aspergillus flavus and efficiently degrading aflatoxin B1 can be obtained by screening and the content of aflatoxin B1 in detoxified peanut meal is lower than the national limited standard and achieves the safe feeding level after the bacillus amyloliquefacien is applied to moldy peanut meal. Furthermore, the detoxification mechanism of the strain is the degradation effect of extracellular metabolites, and generation of the active substance is of a non-induced type, which is an inherent attribute of the strain. The features of the strain provide the possibility for biocontrol of Aspergillus flavus and aflatoxin B1 in industries such as feed and foods and the strain has very high application values.

The invention provides Lysobacter capable of efficiently degrading aflatoxin B1 and ochratoxin A and application of the Lysobacter and particularly provides double-function Lysobacter sp. CW239 and application thereof to the degradation of low-pollution concentration aflatoxin B1 and ochratoxin A. Compared with existing aflatoxin degrading bacteria, the Lysobacter sp. CW239 has the advantages that the Lysobacter sp. CW239 can achieve excellent degrading effect under a low-concentration toxin pollution condition; under a liquid fermentation condition, in fermentation broth, which contains the aflatoxin B1 and ochratoxin A, with the final concentration of 20 microgram/L, the 12-hour ochratoxin A degradation rate of the Lysobacter sp. CW239 is 53.1%, and the 48-hour degradation rate reaches 99.8%; the 12-hour aflatoxin B1 degradation rate of the Lysobacter sp. CW239 is 42.5%, and the 48-hour degradation rate reaches 83.4%; when the Lysobacter sp. CW239 is used for processing feed (with the final concentration of 20 microgram/kg) polluted by toxins, the 48-hour ochratoxin A degradation rate is 68.7%, and the 48-hour aflatoxin B1 degradation rate is 52.1%; the Lysobacter sp. CW239 has substantial application value and significance when being applied to food and feed bio-detoxification.

The invention discloses a biosensor electrode for detecting aflatoxin B1 and a preparation method thereof. The biosensor electrode comprises a substrate layer and a reaction layer provided on the substrate layer. The reaction layer includes an electronic mediator, a sol-gel film and aflatoxin oxidase, wherein the electronic mediator is fixed on the substrate layer, and the sol-gel film embeds the aflatoxin oxidase on the substrate modified by the electronic mediator to form a film, thus obtaining aflatoxin oxidase modified electrode. The inventive biosensor electrode has the advantages of fast response, high signal sensitivity up to 1.5 ppm to 0.125 ppb, high specificity, convenient usage, quantitative detection, long service life and good stability.

The invention discloses a method for preparing an aflatoxin B1 aptamer affinity column and belongs to the field of affinity chromatography and mycotoxin analysis. The method comprises the following steps: adopting epoxy activated agarose microspheres FF as a solid phase carrier; after the solid phase carrier is coupled with an amino-modified aflatoxin B1 aptamer, closing extra active sites in the carrier, and feeding into micro columns. The prepared aptamer affinity column can be specially combined with aflatoxin B1, the adding standard recovery is 70-110, and the aptamer affinity column can be repeatedly used for at least five times.

The invention discloses a light induced chemiluminescent immunoassay reagent kit for aflatoxin B1and a detection method thereof, which belong to the technical field of light induced chemiluminescent immunoassay. A luminescent particle enveloped with AFB1-BSA is added into a microporosity plate, a AFB1 standard or sample, a rabbit anti-AFB1 antibody, a biotin goat anti-rabbit antibody are sequentially added for a photophobic reaction, then a photosensitive particle enveloped with streptavidin is photophobically added, and the mixture is incubated and then is detected. The AFB1-BSA enveloped on the luminescent particle competes with the AFB1 in the standard or sample for connecting to the AFB1 antibody to form a complex with the biotin goat anti-rabbit antibody and the photosensitive particle enveloped with the streptavidin, the energy is transferred to the luminescent particle to produce fluorescence by producing and transferring singlet ionic oxygen under optical excitation, a light induced chemiluminescent detector is used to detect, the intensity of optical signals is inversely proportional to the concentration of the AFB1, and the content of the AFB1 in the measured sample is determined by contrasting with the standard curve. The invention is used to detect the content of the AFB1 in foodstuff, feedstuff and products of the foodstuff and the feedstuff; and the reagent kit has the advantages of simple structure, simple and convenient operation, low cost, short detection time, and high sensitivity.

The invention discloses a preparation method of a composite microbial inoculant for degrading aflatoxin B1 and a composite microbial inoculant prepared by the method. The method comprises the following steps: respectively culturing pseudomonad, Flavobacterium, Rhodococcus, Stenotrophomonas and Bacillus to obtain a pseudomonad solution, a Flavobacterium solution, a Rhodococcus solution, a Stenotrophomonas solution and a Bacillus solution; mixing the pseudomonad solution, Flavobacterium solution, Rhodococcus solution, Stenotrophomonas solution and Bacillus solution to obtain a composite bacterium solution; and putting the composite bacterium solution into a composite bacterium culture medium, and carrying out mixed culture fermentation to obtain the composite microbial inoculant for degrading aflatoxin B1. The composite microbial inoculant can efficiently degrade aflatoxin B1, and has the advantages of low cost and no secondary pollution.

The invention relates to an immunochromatographic test strip for synchronously detecting mixed pollution of aflatoxin and zearalenone, a preparation method and application thereof. The test strip includes a paperboard. An absorbent pad, a detection pad, a gold labeled pad and a sample pad are sticked on one side of the paperboard from top to bottom. Adjacent pads are in overlapping connection at joints. The detection pad adopts a nitrocellulose membrane as a base pad, which is provided with a transverse control line and detection lines. The two detection lines in internal distribution are positioned below the quality control line, and are respectively coated with a zearalenone-bovine serum albumin conjugate and an aflatoxin B1-bovine serum albumin conjugate. The quality control line is coated with a rabbit antimouse polyclonal antibody. The gold labeled pad is horizontally sprayed with a nanogold labeled anti-aflatoxin universal monoclonal antibody and a nanogold labeled anti-zearalenone monoclonal antibody. The immunochromatographic test strip can be used for simultaneously detecting the content of fungaltoxins aflatoxin and zearalenone in a sample, and has the characteristics of simple operation, rapidity, and high sensitivity.

The invention discloses bacillus subtilis for degrading aflatoxin B1 and application of the bacillus subtilis, and belongs to the field of biotechnologies. Primary screening is carried out by the aid of courmarin which is used as a unique carbon source and a unique energy source, AFB1 (aflatoxin B1) degradation rates of strains are used as secondary screening indexes, and accordingly the bacillus subtilis S1 (CCTCC NO:M 2016390) capable of efficiently degrading the AFB1 can be obtained by means of screening. The bacillus subtilis and the application have the advantages that the AFB1 degradation rate of strain fermentation broth can reach 61.36%; the degradation rate can reach 80.26% after the bacillus subtilis is cultured according to an inoculation amount of 10%; the degradation rate can reach 85.65% after fermented supernatant is concentrated by 8 times; as shown in research, the aflatoxin B1 can be degraded by extracellular enzymes secreted by the bacillus subtilis S1, and accordingly the strain fermentation broth or active proteins separated from the strain fermentation broth can be used for degrading the aflatoxin B1 or preparing biological additives for degrading the aflatoxin B1.