39 results about "Acid stress" patented technology

The invention discloses a method for increasing yield of pyruvic acid, belonging to the fermentation engineering field. The method is as follows: when Torulopsis glabrata (CCTCC NO: M202019) is used to ferment and produce pyruvic acid, aspartic acid is added to increase the acid stress resistance of Torulopsis glabrata. When the pH values are 5.5 and 4.5, the yields of pyruvic acid are separately55.8g / L and 30.4g / L which are separately increased by 12.4% (49.6g / L) and 48.4% (20.5g / L) than the control groups without aspartic acid; and the method has better technical effect and wide application prospect.

The invention discloses a method for using the transcription factor Crz1p to regulate acid stress resistance of Toruula glabrata, belonging to the field of bioengineering. In the present invention, by deleting or overexpressing the Cgcrz1 gene of Torulopsis glabrata, the acid stress resistance of the strain is correspondingly reduced or improved. The present invention also compares the cell membrane fatty acid, sterol composition, ratio and permeability of the deletion mutant strain Cgcrz1Δ under acid stress. Acid stress resistance.

The invention relates to a gene capable of regulating and controlling inhibition of vitamin C fermented strain acid production during acid stress and belongs to the technical fields of basic research on vitamin C prepared by fermentation and biological engineering. The key gene for regulating and controlling yield reduction of acid stress induced 2-KLG in the production strains is determined, so a metabolic engineering strategy with high pertinence is generated. The expression condition of genes, in particular membrane transport protein genes, of specific microorganisms in the microorganisms subjected to mixed cultivation is analyzed by an expression profile chip technology. Compared with ketogenic gulonic acid bacteria subjected to single cultivation, the ketogenic gulonic acid bacteria subjected to mixed bacteria cultivation have 45 upregulated membrane transport protein genes and 15 downregulated membrane transport protein genes. The notable thing is that: 7 iron ion transport protein genes are inhibited to express. After acid stress, the iron ion transport protein genes are overexpressed. During fermentation, the iron ions are added to inhibit mixed bacteria to ferment and generate acid. The result shows that the iron ion transport protein exerts reverse action in the process of yield reduction of 2-KLG generated by the acid stress induced mixed bacteria fermentation.

The invention relates to an application of chitosan oligosaccharide and a composition thereof in resisting salinity for crops, and particularly provides a farm chemical composition for crops to resist saline-alkali-acid stress. The farm chemical composition contains the chitosan oligosaccharide, and the weight percentage of the chitosan oligosaccharide in the farm chemical composition is 0.011 to 0.024 percent or 0.005 to 0.019 percent. The farm chemical composition can alleviate the diseases of the crops caused by saline, alkali and acid. The chitosan oligosaccharide with a particular concentration has a positive adjusting action on the growth of the crops under the saline-alkali-acid condition so as to protect the normal growing development of the crops.

The invention discloses an acid pressure simulation method considering the dynamic process of mucovisic acid. The relationship between the viscosity of mucovisic acid and shear rate, temperature, calcium ion concentration, pH value and surfactant concentration is respectively measured, and a mucoviscic constitutive equation is established. ; Simulate the flow and reaction process of viscous acid in the fracture system, and obtain the pressure profile in the fracture system; take the pressure profile in the fracture system as the inner boundary condition, and the ground pressure as the outer boundary condition, simulate the calculation of the variation of viscous acid in the matrix the reaction process; simulate the viscosity change of the acid solution in the matrix system, and calculate the fluid loss velocity; bring the obtained fluid loss velocity into the pressure profile of the fracture system in the step. The invention is used to solve the problem that the acid pressure simulation technology in the prior art does not consider the dynamic filtration process of mucoacid, resulting in a low coincidence rate between the simulated seam length of the mucoacid acid pressure and the actual situation, and realizes that the simulation can be obtained considering the viscous acid. The purpose of acid fracturing fracture morphology after acid dynamic drop rate.

The invention discloses acid stress resistant recombinant lactic acid bacteria and application thereof, and belongs to the field of bioengineering technology. By overexpression of TraG gene derived from L.lactis NZ9000 in L.lactis NZ9000, the recombinant L.lactis NZ9000 (pNZ8148 / TraG) with acid stress resistance remarkably enhanced is obtained. By stress for 3 h at pH 4.0, survival rate of the recombinant strain is 61.3 times higher than survival rate of a contrast. The invention also provides a method for raising acid stress resistance. The method of the invention has good industrial application value.

The invention discloses an acid-stress-resisting component and belongs to the technical field of biological engineering. An rbsA gene obtained from lactococcus lactis (L.lactis NZ9000) is excessivelyexpressed in the lactococcus lactis (L.lactis NZ9000) to obtain recombinant lactococcus lactis (L.lactis NZ9000) (pNZ8148 / RbsA) with the remarkably improved acid-stress-resisting capability. The survival rate of a recombinant strain is 5.8 times as much as that of a control group after the recombinant strain is stressed for 3h under the condition that the pH (Potential of Hydrogen) is 4.0. The invention further provides a method for improving the acid stress resistance; the method has good industrial application value.