8results about How to "Short fermentation cycle" patented technology

This invention provides a proline-producing strain, its construction method, and its applications. The strain is derived from a starting strain using metabolic engineering techniques. E. coli It was obtained through further modifications based on W3110, specifically: knockout. putA、aceA、poxB、 ldhA、ackA、ptsG Genes, upregulated proB74 , proC、 proA、sthA、glf、glk、gdhA The transcriptional level of the gene was downregulated. SucAB The transcriptional level of genes, affecting phosphorylketonease genes BAD_0687 and proline transporter encoding genes cgl2622 Heterologous expression was performed; the strain used glucose as a carbon source, requiring no substrate addition, resulting in low production costs, high production rate, short fermentation cycle, and high strain stability, thus offering significant economic benefits and laying the foundation for large-scale proline production.

This invention discloses a recombinant *Escherichia coli* strain, its preparation method and application, and a method for synthesizing oryzanol A, relating to the field of bioengineering technology. The recombinant *E. coli* strain uses *E. coli* BL21(DE3) as the chassis cell and undergoes the following modifications (a) and (b): (a) knocking out the pfkA gene; or, knocking out the pfkA gene and mutating the 5′ untranslated region of the gltA gene from the sequence shown in SEQ ID NO: 1 to the sequence shown in SEQ ID NO: 2; (b) inserting exogenous genes agmA, agmB, agmC, agmE, and agmF. This recombinant *E. coli* strain exhibits rapid growth, a short fermentation cycle (within 72 hours), can utilize inexpensive and readily available culture media, and significantly increases the fermentation yield of oryzanol A compared to existing *E. coli* systems.

The invention belongs to the field of gene engineering and enzyme engineering, and particularly relates to an activity-improved UDP glycosyl transferase mutant and application thereof. The glycosyl transferase mutant is a four-combination mutant N2HN1I, and the amino acid sequence of the glycosyl transferase mutant is as shown in SEQ ID NO. 4. The mutant provided by the invention has higher catalytic activity, the conversion rate of a substrate crocetin is high, and the mutant has important industrial application value.

This invention proposes a method for preparing selenomethionine, comprising the following steps: S1. Inoculating selenium-resistant Bacillus subtilis into a culture medium containing sodium selenite for activation, and selecting seed culture in the logarithmic growth phase; S2. Inoculating the seed culture into a fermentation medium, providing carbon and nitrogen sources for cell proliferation in the early stage of fermentation, and adding inorganic selenium source and exogenous methionine precursor in the middle and late stages of fermentation, while adjusting dissolved oxygen and pH to reduce inorganic selenium into selenomethionine within the cells; S3. After fermentation, subjecting the fermentation broth to cell disruption, solid-liquid separation, and drying to obtain a product rich in selenomethionine. This preparation method, through staged fermentation, balances cell growth and selenium conversion efficiency, achieving efficient synthesis of selenomethionine from Bacillus subtilis. The product contains selenium primarily in the form of selenomethionine, with a high proportion of organic selenium. The strains used are highly safe, the process is mature, and the application value is significantly improved, making it suitable for industrial-scale production.

This invention discloses a method for fermenting fresh almond flowers with *Lactobacillus plantarum*, the fermentation products, derivatives, and their applications. The method uses fresh almond flowers as raw material. After pretreatment, pulping, substrate preparation, and sterilization, *Lactobacillus plantarum* is inoculated for anaerobic or microaerobic fermentation. After fermentation, enzymes are inactivated and separated to obtain the fermentation expression product. This fermentation expression product is rich in free amino acids, small peptides, aromatic compounds, organic acid derivatives, and polyphenol derivatives, exhibiting a mild and natural aroma and excellent antioxidant and soothing activities. This invention also provides derivatives obtained from further processing of this fermentation expression product, and their applications in cosmetics, skincare products, natural fragrances, and functional foods. This invention features a mild process, is solvent-free, and highly safe, achieving high-value utilization of fresh almond flowers.

The application discloses a sludge anaerobic acid production strengthening method based on synergistic degradation of melanoid-like substances by thermal hydrolysis and potassium permanganate, which comprises the following steps: (1) screening and removing impurities from sludge, and then performing gravity sedimentation and concentration; (2) thermal hydrolysis treatment: high-temperature and high-pressure treatment, pressure relief and cooling; (3) adding potassium permanganate for oxidation, and combining with ultrasonic dispersion; (4) anaerobic fermentation: inoculating active sludge, and controlling fermentation conditions; and (5) separating and extracting short-chain fatty acids. The application realizes the synergistic effect of thermal hydrolysis and potassium permanganate, targets the degradation of melanoid-like substances generated in the thermal hydrolysis process, eliminates the inhibition of the melanoid-like substances on anaerobic microorganisms, and promotes the efficient dissolution of organic matters in sludge. The nano manganese dioxide generated by potassium permanganate oxidation serves as an electron transfer medium, further strengthens the metabolic activity of acid-producing bacteria, and the pickling recovery rate is greater than or equal to 90%. The method makes the yield of short-chain fatty acids increase by 65% (up to 456 mg / g VS), has high efficiency and environmental protection, and provides an innovative solution for sludge resource treatment.

This invention discloses a method for preparing iron-zinc-selenium-enriched yeast, comprising the following steps: (1) adding sterilized inorganic iron solution and inorganic zinc solution to sterilized YPD culture medium, so that the Fe in the culture medium is enriched. 2+ The final concentration is 150-300 mg / L, Zn 2+ The final concentration is 100-300 mg / L, and it is stored at 4℃ for later use; (2) The activated yeast is inoculated into the above culture medium at an inoculation rate of 10%, the initial pH of the culture medium is adjusted to 6-8, the rotation speed is 150-200 r / min, the liquid volume is (50-80) mL / 250 mL, and it is cultured at 28-32℃. When the culture reaches 6 h, sterilized inorganic selenium solution is added to the culture medium to make the Se in the culture medium more concentrated. 2+ The final concentration is 15-30 mg / L, and the culture is continued for (24-48) h. The bacterial cells are collected by centrifugation; (3) The collected bacterial cells are washed and dried to obtain iron, zinc and selenium-enriched yeast. This invention prepares a yeast that can simultaneously obtain iron-enriched yeast, zinc-enriched yeast and selenium-enriched yeast. It has a short fermentation cycle, is easy to cultivate, has a simple process, good stability, high conversion rate of organic iron, zinc and selenium, and is easy to process and store.

This invention relates to a genetically engineered strain for synthesizing retinal, its construction method, and its applications. The construction method involves introducing DNA fragments of the β-carotene 15,15'-oxygenase gene, isopentenyl pyrophosphate isomerase gene, phytoene dehydrogenase gene, geranyl-geranyl pyrophosphate synthase gene, and phytoene synthase gene into *Rhizopus cylindrica* to obtain a genetically engineered strain. This strain enhances the expression of β-carotene 15,15'-oxygenase, isopentenyl pyrophosphate isomerase, phytoene dehydrogenase, geranyl-geranyl pyrophosphate synthase, and phytoene synthase in *Rhizopus cylindrica*. By selecting *Rhizopus cylindrica* as a host, introducing key synthetic genes, and achieving stable genome integration, this method yields an engineered strain capable of efficiently synthesizing retinal using glucose as a carbon source, simplifying the production process, reducing costs, and improving industrial applicability.