90 results about "Riboflavinum" patented technology

The invention belongs to the field of microbial fermentation, and discloses riboflavin-producing bacillus subtilis and a construction method and application thereof. According to the riboflavin-producing bacillus subtilis, at least one gene locus in purR, ribC or pyrE in a bacillus subtilis strain is mutated. The accumulated riboflavin of the bacillus subtilis strain obtained by mutating at leastone gene locus of purR, ribC or pyrE under the fermentation condition is significantly increased. The riboflavin-producing bacillus subtilis is a riboflavin high-yield strain, the produced riboflavinis significantly increased, and a foundation is laid for industrial production of the riboflavin.

The invention provides a yellow cucumber and a planting method thereof and a special light-scattering, cooling and heat radiation control film. The yellow cucumber is yellow, the riboflavin content is 0.079 mg/100 g, and the pantothenic acid content is 0.38 mg/100 g. The planting method comprises a step of covering a light shielding bag, wherein in the step of covering the light shielding bag, the light shielding bag made of the light-scattering, cooling and heat radiation control film is adopted, and the bottom end of the bag is provided with an air vent; a breather pipe is arranged at the air vent of the light shielding bag, and the breather pipe is made of a light-scattering material. The yellow cucumber disclosed by the invention is high in nutritive value, good in taste, and high in ornamental value.

The invention discloses photo-curable silk fibroin hydrogel and a preparation method thereof. The photo-curable silk fibroin hydrogel is prepared by: adding riboflavin and horse radish peroxidase intosilk fibroin solution that acts as a raw material, introducing oxygen continuously under ultraviolet irradiation and room temperature, inducing groups in silk fibroin macromolecules to chemically crosslink, and allowing gelling. The silk fibroin in the photo-curable hydrogel provided herein is mainly of random coil; the photo-curable hydrogel has high light transmittance, high compressive strength and high elasticity and is applicable to tissue repair materials.

The invention discloses a photochemical inactivating system for circulating tumor cells and/or tumor stem cells in blood or blood products and application of riboflavin in preparation of an agent for inactivating the circulating tumor cells and/or the tumor stem cells in the blood or the blood products in a photochemical way. According to the system and application, the circulating tumor cells and/or the tumor stem cells in the peripheral blood are completely induced to be subjected to apoptosis to lose the proliferation ability, so that blood cells, coagulation function and immune function of a patient are maintained to the utmost extent.

The invention discloses a method for rapidly removing hexavalent chromium pollutants by using an electron carrier, and belongs to the technical field of environment. The physiological property that the Shewanella oneidensis MR-1 can be used for removing hexavalent chromium pollutants is used as a basis; a strain is cultured to a stable growth period; thalli are collected and transferred to a reactor to carry out re-suspending; the hexavalent chromium pollutant removal capability of the electron carriers namely riboflavin and anthraquinone-2-sodium sulfonate is measured; under the condition that the concentration of riboflavin is 10-50 [mu]M, the Cr<6+> removal rate of riboflavin is increased to 1.40-2.26 times, the removal rate is increased to 42.0-67.7% from 30.0%, and the Cr<6+> removalrate is higher under the condition that the pH value is equal to 8; anthraquinone-2-sodium sulfonate can also improve the removal speed and removal rate of Cr<6+>, and under a concentration of 100 [mu]M, the maximum removal rate reaches 98.1% and is close to 100%. Hexavalent chromium pollutants can be quickly removed by utilizing the electron carrier, so that the problem of low removal efficiencyof hexavalent chromium pollutants at present is solved, and the method has potential environmental remediation and application values.

The invention provides an inactivation device and inactivation method for a riboflavin photochemical blood product. The inactivation device can be arranged on an object placing surface (60). The inactivation device comprises a shell (10), a first light-emitting plate (13), a second light-emitting plate (16) and a movable supporting plate (19). The shell (10) is provided with an inactivation compartment (11) and a hatch (12). The inactivation chamber (11) has an extension direction that can be perpendicular to the object placing surface (60). And the hatch (12) is communicated with the inactivation compartment (11) and has a hatch orientation perpendicular to the extension direction. The invention also provides an inactivation method of the riboflavin photochemical blood product. With a mode of combination of riboflavin with light source irradiation, parasite, bacteria, viruses and white blood cells in the blood product are inactivated, so that the inactivation efficiency is improved and thus the safety of the blood product is improved. The structure is simple and the inactivation device is suitable for being used in various occasions.

The invention discloses recombinant shewanella algae capable of producing riboflavin and an application of the recombinant shewanella algae in electricity production, wherein the recombinant shewanella algae is constructed by the following method: (1) connecting five target genes ribA, ribC, ribD, ribE and ribH in a flavin synthetic route to a vector pyydt to obtain a recombinant plasmid R5; and (2) transferring the recombinant plasmid R5 into a shewanella algae scs-1 CGMCC No.18696 strain, so as to obtain the recombinant shewanella algae scs-R5 for producing riboflavin. According to the recombinant bacterium disclosed by the invention, the yield of riboflavin serving as an electron transfer body is high, so that the electricity generation capacity is improved.

The invention discloses a method and a fermentation device for increasing yield of riboflavin by using an oxygen carrier. The method comprises the steps as follows: S1, seed culture: inoculating a seed culture medium with a riboflavin producing bacillus subtilis strain for culture to obtain a seed culture solution; and S2, fermentation culture: inoculating a fermentation culture medium with the obtained seed culture solution, then, adding the sterile oxygen carrier, and performing fermentation to obtain the riboflavin. The proper oxygen carrier is added to the culture medium, culture is performed in the fermentation device, the dissolved oxygen concentration in the culture medium is increased by chemical and physical methods, thallus metabolism of the riboflavin producing bacillus subtilisis promoted, the substrate conversion rate is increased, the synthetic amount of riboflavin is increased from 11424 [mu]g/mL to 15820 [mu]g/mL, besides, the fermentation cycle is shortened, and the production cost is reduced.

The invention provides an engineering bacterium of Geobacillusthermoglucosidasius and a construction method and application of the engineering bacterium. The construction method includes: through genetic engineering of Geobacillusthermoglucosidasius, introducing ribC (G199D) point mutation, sequentially knocking out purR, purA, ccpN and ldh genes, and then introducing an expression vector carryinga riboflavin synthesis gene cluster into the transformed engineering bacteria to obtain a series of high-temperature riboflavin-producing geobacillus engineering bacteria. The results show that yieldof riboflavin after fermentation of geobacillus after genetic engineering for 24 h is 520 mg/L; and through mixed fermentation with glucose and xylose for the strain, the yield can reach more than 1g/L. The engineering bacterium has advantages of high growth temperature and short generation time, can utilize an inexpensive carbon source, and can be used for large-scale production of riboflavin at low cost.

The invention belongs to the technical field of biology, and particularly relates to a bacillus subtilis strain B13 and application thereof. According to the bacillus subtilis strain B13, the preservation number of the strain is CCTCC M 2020854, and the strain is preserved in the China Center for Type Culture Collection (CCTCC) on December 4, 2020. According to the bacillus subtilis strain B13 disclosed by the invention, after the strain is subjected to heavy ion mutagenesis, the shake flask fermentation yield of riboflavin is remarkably improved, and the bacillus subtilis strain B13 can be used as a strain for industrial production of enterprises and meets the requirements of the market on riboflavin.

The present invention relates to a method of producing riboflavin in a genetically modified organism of the genus Eremothecium, wherein said genetic modification is linked to the fatty acid uptake and/or beta-oxidation pathway of said organism, comprising growing said organisms in a culture medium and isolating riboflavin from the culture medium. The invention further relates to a method of providing a riboflavin accumulating organism belonging to the genus Eremothecium by genetically modifying said organism, to organisms obtained by such a method, as well as the use of such genetically modified organisms for increasing the accumulation of riboflavin.

The invention relates to a method for increasing the yield of riboflavin produced by fermentation of bacillus subtilis, which belongs to the technical field of gene engineering. The method comprises the steps of carrying out genetic modification on a riboflavin production strain; removing the activation mechanism of intracellular high-level GTP on pyr operon; and stabilizing the expression of pyroperon at a low level to reduce the metabolic flux of pyrimidine nucleotide from the first synthesis route and increase the proportion of PRPP entering the purine nucleotide synthesis route. The yieldand yield coefficient of riboflavin are improved, and the fermentation cost of riboflavin is reduced.

The invention provides a method for improving riboflavin production capacity of escherichia coli engineering bacteria by using DNA shuffling, and relates to the field of genetic engineering, and the method comprises the following steps: constructing riboflavin-producing escherichia coli engineering bacteria containing 26 genes; carrying out DNA rearrangement and directional screening on the T7RNA polymerase gene expression unit, and extracting to obtain a first batch of positive plasmids; carrying out DNA rearrangement and directional screening on a riboflavin biosynthesis and transport system, and extracting to obtain a second batch of positive plasmids; carrying out DNA rearrangement and directional screening on the Escherichia coli sigma factor gene, and extracting to obtain a third batch of positive plasmids; introducing the third batch of plasmids into different chassis cells to obtain recombinant strains; and selecting the positive strain with the highest riboflavin yield. The toxicity problem of T7RNAP to an escherichia coli host in the construction process of the riboflavin-producing escherichia coli engineering bacteria, the feedback inhibition problem of a product and the moderate and coordinated expression problem of a constructed riboflavin biosynthetic gene are effectively eliminated. The efficiency and the yield of biosynthesis of riboflavin by the escherichia coli engineering strain are further improved.

The invention discloses a photo-crosslinked chitosan-riboflavin edible film and a preparation method thereof. The preparation method comprises the following steps of weighing a certain amount of chitosan powder, and adding the chitosan powder into an acetic acid solution to prepare a chitosan solution, adding a certain amount of glycerol into the chitosan solution as a plasticizer, then adding a proper amount of riboflavin powder under a dark condition, and uniformly stirring to obtain a mixed solution, removing bubbles from the mixed solution, casting the mixed solution on a flat plate, and irradiating the flat plate under ultraviolet light to form a film, and finally, drying the film on the flat plate, and stripping from the flat plate to obtain the film. Chitosan and riboflavin are used as raw materials, the edible film which is green, non-toxic, environmentally friendly and good in stability is prepared, the molecular property of chitosan is improved through a photo-crosslinked method, and under excitation of illumination, the chitosan edible film which is good in physical and chemical performance and remarkably improved in antibacterial effect is prepared.

The invention discloses a genetically engineered bacterium for efficiently synthesizing riboflavin and application of the genetically engineered bacterium, and belongs to the technical field of biological fermentation. The genetically engineered bacterium has the advantages that genes for encoding purR are knocked down, genes for encoding glnR and tnrA are knocked down, hemoglobin from vitreoscilla is overexpressed, dissolved oxygen limitation in the fermentation process is relieved, the energy consumption in the fermentation process is reduced, and the riboflavin yield is increased; and the riboflavin yield of the constructed engineered strain RF1-aPaGaTgV is increased by 50.78% at a shake flask stage, and reaches 2.51 g/L. At the 5-L fermentation level, the highest yield of the riboflavin obtained by adopting the constructed RF1-aPaGaTgV is increased by 45.51% and reaches 10.71 g/L.