63 results about "Indicator bacteria" patented technology

A recombinant phage system has been developed for the rapid detection of bacteria, particularly fecal coliform indicator bacteria. The systems of the invention link phage infection events to quorum sensing signal molecule biosynthesis and bioluminescent bioreporter induction, facilitating the detection of pathogens that may be present in low numbers. The phage-based systems of the invention maintain specificity for the pathogen while still producing significant signal amplification for sensitive and quantitative detection. The systems require only the combination of sample with phage and bioreporter organisms; no extraneous addition of any substrates or user intervention of any kind is necessary, making this approach significantly less technical than standard molecular or immunological methods.

The invention relates to bacillus stearothermophilus and a method for carrying out antibiotic residue detection by utilizing the same. The preservation number of the screened strain is CGMCC NO.3287; and the antibiotic residue detection method which is established by taking the strain as indicator bacteria comprises the following steps of: rejuvenating and activating the strain; preparing spore suspending liquid in enrichment; preparing a purple culture solution; embedding bacillus; detecting a sample, and the like. The strain CGMCC NO.3287 is stable, easy to store and prepare, highly sensitive to B-lactam antibiotic, good in homogeneity and dispersibility in a culture medium, grows fast at 65 DEG C and has fast metabolism and acid production. Compared with a TIC method and a fermentation test method, the method has convenient operation, high sensitivity, 2-3h time-consumption which is shorter than 4h of national similar methods and is easy to judge the result; compared with a commercial kit, the bacillus stearothermophilus has low cost which is equal to 1/7 of the kit in price; and the method is simple and practicable and can be operated in a common laboratory.

The invention discloses bacillus subtilis JN005 and application thereof in prevention and control of rice blast. The preservation number of the strain JN005 is CCTCC No: M2015228. According to the invention, the strain JN005 is utilized to prevent and control the rice blast, so as to avoid potential bad influence of chemical prevention and control on environment and rice safety and disease risk of disease-resistant variety utilization. The strain JN005 living bacteria and metabolite thereof have good prevention and control effect on rice blast and have protection and control effects, and can be developed to dosage forms of the living bactericide and metabolite thereof. In addition, the strain JN005 has inhibition effect on multiple pathogeny indicator bacteria.

The invention provides a suspension type biological indicator of which the stability is good and spores are not easy to sprout. The biological indicator comprises a plastic tube of which the two ends are sealed by fusing, wherein bacterial tablets and a culture medium ampoule tube are arranged in the plastic tube; the invention further provides the preparation method of the biological indicator, and the preparation method comprises the following steps: sealing one end of the plastic tube by fusing for standby application; allowing a hydrophilic support to carry a specified number of spores and drying the spores to form the bacterial tablets, and encapsulating a recovery medium with pH indicating liquid in a glass tube to form the culture medium ampoule tube; placing the bacterial tablets and the culture medium ampoule tube in the plastic tube, and sealing the other end of the plastic tube by fusing. According to the suspension type biological indicator and the preparation method thereof, provided by the invention, the spores are in a dry state and the quality stability of the products is improved, during storage, the spores are isolated from the liquid recovery medium, therefore the spores do not grow, even the storage temperature is the same as the spore growth temperature, and the biological indicator can be stored at room temperature. The suspension type biological indicator can serve as indicator bacteria of various spores that are different in growth temperatures.

The invention relates to antibacterial peptide derived from anchovy cooking waste liquid and an antibacterial peptide separation method. The antibacterial peptide separation method is characterized in that a food-grade enzymic preparation is used for enzymolysis of anchovy cooking waste liquid concentrate, the antibacterial peptide in the anchovy cooking waste liquid concentrate is separated by combination of simulated cell membrane equilibrium dialysis and high-performance liquid chromatography, the amino acid sequence of the purified peptide is analyized, and the activity of the amino acid sequence is verified. The result shows that the antibacterial peptide is decapeptide, and the amino acid sequence of the antibacterial peptide is GLSRLFTALK. The antibacterial peptide has antibacterial activity to seven types of indicator bacteria such as staphylococcus aureus and escherichia coli. The amino acid sequence GLSRLFTALK is obtained through enzymolysis, has the characteristics of high safety and strong antibacterial property and has a potential utilization value in industries such as medicines, food and feed. The antibacterial peptide separation method realizes the targeting separation by using the binding characteristics of a simulated cell membrane of the antibacterial peptide and overcomes the shortcomings of too many steps and long time consumption existing in a conventional peptide separation method. The antibacterial peptide separation method has the advantages that fish processing wastewater is used as a raw material, the environmental pollution is reduced, and the added value of the product is increased.

The invention discloses a quantitative prawn disease prediction method based on intestinal tract bacterial indicators. The quantitative prawn disease prediction method is characterized in that prawn health condition indicator bacteriophyta are screened based on bioinformatics, and characteristic design specific primers are formed based on prawn intestinal flora; real-time quantitative PCR is adopted to detect the relative abundance of the health indicator bacteriophyta, the relative abundance of the health indicator bacteriophyta and its indicating weight are used as independent variables to self-establish a prediction model, and quantitative disease prediction during prawn breeding is achieved. The method has the advantages that the influences of diseases on intestinal flora at different growth stages are distinguished, the accuracy rate of prediction is improved, meanwhile the cheap disease prediction method is established and has a very high actual application value, a basis can be provided for formulation of a coping and intervention measure, for example, design of probiotics, and the method has the good pushing effect on reduction of the prawn breeding risk.

The invention discloses a screening method for clostridium butyricum producing efficient antibacterial peptide butyrisin. The method includes the following steps in order: 1) performing preliminary screening based on the bacteriostatic activity of a fermentation bacterial broth: taking Escherichia coli and Staphylococcus aureus as the indicator bacteria to perform preliminary screening on to-be-tested strains, thus obtaining clostridium butyricum having antibacterial activity on Escherichia coli and Staphylococcus aureus; and 2) verifying the expression of antibacterial peptide butyrisin protein gene by PCR. The PCR positive strain is clostridium butyricum producing efficient antibacterial peptide butyrisin. By the method provided by the invention, the clostridium butyricum producing efficient antibacterial peptide butyrisin can be obtained. The antibacterial peptide has antibacterial activity on bacteria including but not limited to E.coli ATCC25922, E.coli K88, S.aureus ATCC25923 and the like.

The invention discloses a separation method for soil antagonistic bacteria, and relates to the technical field of microorganisms. The separation method for the soil antagonistic bacteria comprises thefollowing steps: A, preparing raw materials, B, preparing a soil suspension, C, diluting, D, preparing an isolation medium, E, performing culture, F, carrying out selective separation, G, preparing an indicator bacteria plate, and H, screening. According to the invention, the antagonistic bacteria are separated from soil through a dilution separation method, actinomycetes in the medium are screened through adding phenol liquid to the medium, and the antagonistic bacteria with the strongest antibacterial effect in the medium are screened through an indicator bacteria plate confrontation method, and are developed into a biocontrol preparation for biocontrol of plant diseases, thereby having good market application prospects. The separation method for the soil antagonistic bacteria disclosedby the invention simplifies the steps of separating the antagonistic bacteria, can quickly separate the antagonistic bacteria from the soil, and improves the separation success rate and separation efficiency of the antagonistic bacteria.

The invention discloses an antimicrobial peptide cecropin A mutant and a coding gene, a preparation method and application thereof. The amino acid sequence of the mutant is as shown in SEQ ID No: 3. The nucleotide sequence of a gene for encoding the above mutant is as shown in SEQ ID No: 4. Molecular cloning is carried out according to the gene sequence of the antimicrobial peptide mutant PEW300 at the design site, and the gene was cloned into a recombinant expression vector; and through fusion expression with a self-aggregation short-peptide ELK16, high-efficiency expression of the mutant PEW300 is realized. Then, bacteriostasis performance test of 9 indicator bacteria is carried out on the mutant peptide PEW300, and the results show that bacteriostasis performance of the antimicrobial peptide PEW300 is greatly improved and the antimicrobial peptide PEW300 has strong pH and heat stability.

The invention discloses a kit for detecting colorectal cancer indicator bacteria. The kit is characterized by comprising the following components: a specific primer combination for identifying the indicator bacteria, wherein the primer combination is shown as SEQ ID NO. 1-14, and the indicator bacteria are the combination of fusobacterium nucleatum (F.nucleolus), anaerobic digestion streptococcus(P.anaerobicus), clostridium symbiosum (C.symbiolum), Porphyromonas saccharolytica (P.asaccharolytica), Prevotella intermedia (P.intermedia), Bacteroides fragilis (B.fragilis) and Streptococcus salivarius (S.salivarius). The kit for detecting colorectal cancer indicator bacteria disclosed by the invention has the beneficial effects that the colorectal cancer can be identified only by collecting astool sample. The principle is that the aim of identifying the colorectal cancer by detecting the colorectal cancer pathogenic bacteria in excrement, the sensitivity can reach 92.9%, and the specificity is 92.6%.

The invention relates to indicator bacteria using alternaria alternata as biological value detection. A high performance liquid chromatography (HPLC) chemical detecting method is combined, and the content of polyoxin B in samples can be rapidly and quantitatively detected. The detecting method uses self-made wooden discs as detecting tools, the number of the detected samples is nine times that ofthe a traditional method, corresponding standard curves correspond to the detecting glass wooden discs, the samples with high biological value can be rapidly and precisely screened, the chemical content of the samples with high content is detected by HPLC, the production cost is reduced, the labor intensity is reduced, and the method can be used for monitoring of the polyoxin B bacteria in the high-throughput screen and production processes.

The invention provides a method for quick combinative monitoring of total coliform and escherichia coli. Water fecal pollution indicator bacteria including total coliform and escherichia coli are defected through the most probable number duplex PCR (MPN-dulpex PCR) method. The method is simple and quick, only four steps of experiments are needed, and the detection rate is higher than that of the national standard multi-tube fermentation method; specificity is high, repeatability is good, and two alive indicator bacteria including total coliform and escherichia coli in water can be monitored at the same time in a combinative and quantitative mode. A new method is provided for quick combinative monitoring of the water fecal pollution indicator bacteria including total coliform and escherichia coli.

Methods and kits for sampling mucous from within a sinus to determine if a single sample includes one or more bacterial types indicating a bacterial infection, such as bacterial sinusitis, and one or more viruses indicating a viral infection, such as influenza.

The invention discloses a method for screening alpha-ketone adipoyl-7-aminocephalosporanic acid acylase-producing bacteria. The screening process of the method comprises the following steps: (1) preparation of alpha-ketone adipoyl-7-aminocephalosporanic acid and structural analogues thereof; (2) selection and culture of screening system indicator bacteria, enrichment culture of candidate bacteria, and selection and culture of positive and negative control strains; (3) preparation of a three-tier agar plate culture medium screening system; (4) judgement of the objective alpha-ketone adipoyl-7-aminocephalosporanic acid acylase-producing bacteria. According to the method, simple operation is achieved, no expensive and complex experimental instrument is needed, 5000 candidate strains can be screened by one person per day, high screening efficiency is achieved and high throughput screening is obtained. Moreover, the method can be used in breeding of industrial strains.

The invention discloses Rhodopseudomonas palustris P-3. The preservation number of the Rhodopseudomonas palustris P-3 is CCTCC (China Center For Type Culture Collection) NO: M 2020808. According to the strain, photosynthetic bacteria are separated and purified by adopting a double-layer plate coating method and a streaking method, vibrio parahaemolyticus, vibrio vulnificus and vibrio anguillarum are used as indicator bacteria, and the bacteriostatic action of the marine photosynthetic bacteria strain is determined by adopting an oxford cup method. Naphthalene ethylenediamine hydrochloride spectrophotometry and indophenol blue spectrophotometry are adopted to determine the nitrite nitrogen and ammonia nitrogen degradation effects of different strains, and screening is performed to obtain the product. The strain P-3 has the composite functions of resisting vibrio and efficiently degrading nitrite nitrogen and ammonia nitrogen, has a strong inhibition effect on vibrio anguillarum, has thestrongest effect on vibrio anguillarum, and also has a certain nitrite nitrogen and ammonia nitrogen degradation effect. The strain P-3 is cultured in a culture medium containing 50mg/L ammonia nitrogen and nitrite nitrogen for 4 days, the degradation rates are 89.68% and 94.98% respectively, and the strain P-3 has a wide application prospect.

The invention provides a preparation method and application of a bombyx mori antibacterial peptide BMGlvA2 recombinant protein, and the amino acid sequence of the bombyx mori antibacterial peptide BMGlvA2 recombinant protein is as shown in SEQ ID NO. 1. The invention relates to the field of gene engineering, and an engineering strain Trichoderma reesei is used as an expression host to realize expression of the bombyx mori antibacterial peptide BMGlvA2 recombinant protein. Escherichia coli, salmonella and clostridium perfringens are used as indicator bacteria at the same time for the first time, and it is identified that the antibacterial peptide fermentation product have obvious antibacterial activity on the indicator bacteria. The invention also characterizes the self properties of temperature tolerance, digestive enzyme tolerance, hemolytic activity and the like of the antibacterial peptide, and also preliminarily provides an inhibition mechanism of the antibacterial peptide on clostridium perfringens. The bombyx mori antibacterial peptide BMGlvA2 provided by the invention is beneficial to further development and application in the field of feeds.

The invention relates to the technical field of microbial screening, and in particular, relates to a screening method for lactic acid bacteria. The method includes the steps: grinding a sample firstly, and then carrying out enlarged cultivation; then growing on a culture medium by a tilt-pour process so as to separate single colonies of lactic acid bacteria; inoculating an MRS flat plate with indicator bacteria with single colonies by a bacteria dotting manner, and covering with MRS soft agar; selecting strains with a bacteriostatic effect, and carrying out purification and preservation of thesingle colonies; and finally, verifying. The strains separated and screened by the method not only can reduce the impact of other miscellaneous bacteria in early stage, but also can eliminate the non-bacteriostatic lactic acid bacteria, can reduce the workload, also can screen the required strains for inhibiting pathogenic bacteria more pertinently.

The invention relates to a method for producing bacteriostatic active substances by bacillus amyloliquefaciens and belongs to the technical field of microbes. The method comprises the steps of culturing the bacillus amyloliquefaciens so as to obtain fermentation supernatant, and subjecting the supernatant to separating and purifying, thereby preparing a novel hexapeptide. According to the method provided by the invention, the obtained fermentation supernatant can be directly applied to bacteriostasis, three kinds of bacteriostatic substances can be obtained after further separating and purifying the fermentation supernatant and comprises the novel hexapeptide which similarly has a bacteriostatic action; and when the three kinds of bacteriostatic substances jointly act on indicator bacterium cells, the extent of damage to the cells is greater. Discovered by results of acting on indicator bacteria by pairwise combinations of the three kinds of bacteriostatic substances, lactic acid and Surfactin have a synergistic action, the lactic acid and the hexapeptide have a synergistic action, and the Surfactin and the hexapeptide have an additive action. A theoretical support is provided forcontinuous development of novel antibacterial peptides, and a new way of think is provided for efficient use of natural bacteriostatic substances.

The invention discloses a method for determining an antibacterial mechanism of a zeolite molecular sieve antibacterial agent by high performance liquid chromatography. The zeolite molecular sieve antibacterial agent is taken as a research object, escherichia coli and staphylococcus aureus are taken as indicator bacteria, and content changes of staphylococcus aureus mycoprotein and content of beta-lactamase in escherichia coli after action of the antibacterial agent are determined by means of high performance liquid chromatography to realize expounding of the antibacterial mechanism of the zeolite molecular sieve antibacterial agent. The method is simple in operation, high in sensitivity, low in sample consumption and quick in detection. Along with increase of the concentration of the antibacterial agent, HPLC (high performance liquid chromatography) peak area is reduced, and protein content is decreased, so that the bacterial structure is changed and even completely damaged, bacteria fail to grow normally since cell metabolism and growth are affected, and bacterium inhibition and killing are realized.

Lactobacillus sake is a natural food preservative and feed additive with potential development capacity; the lactobacillus sake is simplex in obtaining method and small in yield, so use and popularization of the lactobacillus sake are seriously influenced; meanwhile the lactobacillus sake is complex in preparation step and high in expenditure. A method for obtaining the lactobacillus sake by separating, screening and identifying bacteriocin producing lactic acid bacteria includes the steps of firstly, primary screening work of strains; secondly, secondary screening work of the strains, wherein in the secondary screening of the strains, an antibacterial test is conducted on a plurality of lactic acid bacteria strains obtained in the first step with gram-positive bacteria and gram-negative bacteria as indicator bacteria, and the strains which can inhibit gram-positive bacteria and gram-negative bacteria and have the dual inhibition characteristic are selected; thirdly, fermentation characteristic test work; fourthly, inspection of influences of other factors on the strains; fifthly, inspection of influences of pH and temperature on bacteriocin crude extracts; sixthly, physiology and biochemistry identification work and molecule identification work.