9 results about "Citric acid fermentation" patented technology

The invention belongs to the technical field of fermentation engineering, and particularly relates to an alpha-ketoglutarate dehydrogenase mutant and application thereof. Compared with wild-type alpha-ketoglutarate dehydrogenase, the mutant or the salt thereof has the advantage that the enzyme activity is obviously reduced, so that when aspergillus niger containing the mutant or the salt thereof is used for citric acid fermentation, the yield and / or the yield of citric acid can be increased.

This application discloses a method for reducing the oxalate content in the production of anhydrous citric acid, belonging to the field of organic acid refining technology. The method involves adjusting the pH of the citric acid fermentation broth to 2.5-3.0, adding a MnO2-γ-Al2O3 catalyst, and catalytically oxidizing and degrading oxalic acid into CO2 and H2O under oxygen-containing gas conditions. After the oxalate content reaches the target level, the pH of the reaction solution is raised to 3.5-4.0 to passivate the catalyst and terminate the reaction. After filtration and catalyst recovery, the filtrate is treated to obtain the finished anhydrous citric acid product. This method can be implemented in existing production lines, the catalyst can be recycled more than 15 times, the oxalate removal rate is ≥90%, and the oxalate content of the finished anhydrous citric acid product can be reduced to below 20 ppm. It is suitable for the production of food-grade, pharmaceutical-grade, and electronic-grade anhydrous citric acid.

This invention belongs to the field of microbiology, specifically relating to a method for cultivating Aspergillus niger spores using a highly permeable expanded rice husk-wheat bran composite substrate. The method employs a composite substrate formed by combining expanded modified rice husk with wheat bran, overcoming the inherent limitations of a single wheat bran substrate. A fibrous skeletal structure is constructed through high-temperature expansion pretreatment of crushed rice husk, followed by precise blending with wheat bran, significantly improving the substrate's permeability and heat dissipation, and optimizing temperature uniformity. Furthermore, only two turning operations are required to complete the cultivation of Aspergillus niger spores, significantly reducing labor intensity and the risk of contamination. The addition of specific nutrients optimizes the culture medium, achieving increased spore yield and viability while shortening the cultivation cycle, thus balancing practicality and economy. This method can be directly applied to the large-scale cultivation of Aspergillus niger in citric acid fermentation, meeting the needs of industrial-scale applications.

The application provides a long-acting liquid organic fertilizer capable of enhancing salt and alkali tolerance of crops and a preparation method and application thereof, and belongs to the technical field of crop planting. The long-acting liquid organic fertilizer takes fermented tail liquid of citric acid, inorganic chemical fertilizer, micro-fertilizer and strigolactone as raw materials, and comprises the following effective components: organic matter of 220 g / L or more, N of 100 g / L or more, P2O5 of 60 g / L or more, K2O of 40 g / L or more, boron and zinc of 1 g / L or more, and strigolactone of 25 micromoles / L. The raw material components in the long-acting liquid organic fertilizer cooperate with each other and have synergistic effect, and jointly play the roles of promoting crop growth, increasing biomass, improving chlorophyll content, improving nutrient utilization rate and salt and alkali tolerance. In addition, the application is also of great significance in solving environmental pollution, recycling waste liquid, reducing fertilizer production cost and developing green and healthy agriculture.

The invention discloses a method for producing citric acid through fermentation, and belongs to the technical field of citric acid fermentation. Comprising the following steps: S1, crushing corn to obtain corn flour, adding water for size mixing, adding enzyme, and liquefying to obtain corn liquefied liquid; s2, adding the corn liquefied liquid obtained in the step S1 into a seed tank, adding ammonium sulfate, carrying out heating disinfection, cooling to 37 DEG C, inoculating aspergillus niger spores, and carrying out seed liquid culture; s3, pumping the corn liquefied liquid obtained in the step S1 into a fermentation tank, adding a citric acid synthesis accelerant, uniformly stirring and mixing, heating and disinfecting, and cooling to 36.5 DEG C; and S4, transferring the seed solution obtained in S2 into the fermentation tank in S3, so that the concentration of pellets in the fermentation solution reaches 3 * 10 < 4 > pellets / mL, and keeping ventilation until the fermentation is finished. In the process design of fermentation production of citric acid, efficient synergy is formed through precise optimization of each step, efficient synthesis of citric acid is finally realized, and improvement of production efficiency, control of raw material cost and stability of process operation are taken into account.

The utility model relates to citric acid production technical field discloses a kind of dissolving oxygen devices for fermentation production citric acid, including fermentation tank, the top of the fermentation tank is fixedly connected with top cover, the top of the top cover is fixedly connected with the power component of driving, the outside of the power component is fixedly connected with the stirring component of rotating, the outside of the fermentation tank is fixedly connected with external cylinder, the outside of the external cylinder is fixedly connected with the storage component of placing, the inside sliding connection of the external cylinder has conical barrel, the outside of the conical barrel is fixedly connected with connecting rod, the outside of the connecting rod is fixedly connected with inclined surface block, the inside fixed connection of the conical barrel has telescopic link.The utility model in, when citric acid fermentation is put to raw material, by motor drive rotating rod with stirring frame one pair of inclined surface block is extruded, so that the ration of raw material is discharged, to accurately control the addition amount of raw material.

The stirrer comprises a hub arranged on the periphery of a stirring shaft in a fermentation tank, a rotating disc is installed on the outer side of the hub, a plurality of paddles are evenly arranged on the periphery of the rotating disc, and each paddle comprises an upper arc-shaped plate and a lower arc-shaped plate which are oppositely arranged on the upper side and the lower side of the rotating disc; and the inner arc surfaces of the upper arc-shaped plate and the lower arc-shaped plate face the rotating direction of the turntable. According to the stirrer disclosed by the utility model, the flowing direction of fermentation liquor in the fermentation tank is changed by utilizing the inner arc surface of the arc-shaped plate, and the generated shearing force is small, so that aspergillus niger hyphae can form mycelium pellets more easily, and the fermentation efficiency is improved; one end, far away from the rotating disc, of the lower arc-shaped plate of the paddle faces the bottom of the fermentation tank, fermentation liquor flows to the bottom of the fermentation tank during stirring, and solid particle deposition is avoided by impacting the bottom of the fermentation tank through the fermentation liquor; the stirrer guides fermentation liquor to the upper end and the lower end of the fermentation tank through the upper arc-shaped plate and the lower arc-shaped plate respectively, so that backflow is formed in the upper layer and the lower layer in the fermentation tank, and comprehensive stirring of the fermentation liquor is effectively promoted.

The application provides a high-calcium foliar fertilizer capable of enhancing salt and alkali tolerance of crops, and a preparation method and application thereof, and belongs to the technical field of crop planting. The high-calcium foliar fertilizer takes citric acid fermentation tail liquid, inorganic chemical fertilizer and anhydrous calcium chloride as raw materials, and comprises the following effective components: organic matter of 0.4 g / L or more, N of 0.2 g / L or more, P2O5 of 0.12 g / L or more, K2O of 0.08 g / L or more, and 0.25% to 2.0% of anhydrous calcium chloride. The raw material components in the high-calcium foliar fertilizer are mutually matched and synergistically enhanced, and jointly play a role in significantly enhancing the salt and alkali tolerance of crops, and have remarkable application effects in improving the biomass of crops, promoting the growth of crops, improving the photosynthetic capacity, resisting active oxygen damage, and expelling salt base ions. In addition, the application is also of great significance in solving environmental pollution, recycling waste liquid, reducing the production cost of fertilizers, and developing green and healthy agriculture.

The present application relates to the field of citric acid fermentation, and discloses an aspergillus niger seed, a preparation method thereof and a method for fermenting citric acid by using aspergillus niger. The preparation method comprises the following steps: inoculating aspergillus niger spores into a seed culture medium, and culturing in the presence of a porous carrier to obtain the aspergillus niger seed; wherein the pore size of the porous carrier is 200-500 PPI. The aspergillus niger seed prepared by the method enables aspergillus niger to ferment in the form of mycelium during fermentation, which can reduce the inoculation amount, improve the acid production efficiency, and reduce energy consumption.