4 results about "Streptomyces phaeochromogenus" patented technology

The invention provides a method for improving the fermentation level of avilamycin, which comprises the following steps: step 1, seed tank culture: preparing a spore solution from maturely cultured streptomyces viridochromogenes, and inoculating the spore solution into a seed tank to obtain a mature seed solution; step 2, culturing in a fermentation tank: inoculating the grown mature seed liquid into a fermentation culture medium according to an amount which is 10 percent of the volume of the inoculated mature seed liquid in the fermentation tank, and supplementing an L-valine solution, a sodium acetate solution, phytine turbid liquid and liquefied starch in the culture process, so as to obtain avilamycin fermentation liquid. According to the method, key supplements including phytin and sodium acetate are supplemented, the utilization efficiency of avilamycin A precursors and carbon sources is effectively improved in the avilamycin fermentation process through the two key supplements, the fermentation level is improved to 7329 mu g / mL from 6126 mu g / mL, the fermentation level is improved, the maximum single impurity content is effectively controlled, and finally the quality of fermentation liquor is greatly improved.

This invention discloses an engineered bacterium producing tetracrine, its construction, and its application. The invention utilizes a strong promoter to drive the high expression of regulatory genes ovmZn and ovmWn in *Streptomyces neyagawa*, constructing a recombinant engineered strain Sne / pZWn; alternatively, it utilizes a strong promoter to drive the high expression of homologous genes of both, including the regulatory genes ovmZ and ovmW from *Streptomyces chromogenicus*, in *Streptomyces neyagawa*, constructing a recombinant engineered strain Sne / pZW. These engineered strains can express previously silenced gene clusters, activating tetracrine biosynthesis and laying the foundation for the development and application of tetracrine.

The invention discloses a method for obtaining a high-yield epsilon-polylysine streptomyces diastatochromogenes engineering strain S.diastatochromogenes MDH-OGDH by overexpressing a key enzyme malic dehydrogenase gene MDH and an alpha-ketoglutaric acid decarboxylase gene OGDH in a TCA (Trichoderma Carboxygenase) pathway, the epsilon-polylysine is produced by fed-batch fermentation in a 5L fermentation tank, and the yield (g / L) of the epsilon-polylysine is 137.18% of that of a chassis strain S.diastatochromogenes 6 #-7, and the yield (g / L) of the epsilon-polylysine is 37.18% of that of the chassis strain S.diastatochromogenes 6 #-7. The production intensity (g / L.h) of the strain is 133.68% of that of a chassis strain S.diastatochromogenes 6 #-7; the saccharic acid conversion rate of the strain is 116.04% of that of a chassis strain S.diastatochromogenes 6 #-7, the production cost is remarkably reduced, and an excellent strain is provided for industrial production of epsilon-polylysine.

The invention discloses a preparation method of avilamycin fermentation liquor, and belongs to the technical field of microbial fermentation. According to the method, streptomyces viridochromogenes is used as a strain, a fermentation production culture medium with a specific formula is adopted for fermentation, the fermentation process is precisely controlled through feeding by a flow addition method, and finally the avilamycin fermentation liquor is prepared. By optimizing a culture medium formula and a fermentation process, the fermentation titer of avilamycin reaches more than 6500u / ml, the fermentation time is controlled within 200h, the problems of low fermentation yield and high energy consumption in the prior art are effectively solved, and the method is suitable for industrial production.