6 results about "Nitrosoguanidines" patented technology

The invention relates to the technical field of microorganisms, in particular to a beta-1, 4-endo-xylanase gene BsxynA and application of the beta-1, 4-endo-xylanase gene BsxynA. According to the application, the beta-1, 4-endo-xylanase gene BsxynA is screened and identified, in-vitro induced expression is performed on the beta-1, 4-endo-xylanase gene BsxynA for the first time, and enzymatic properties of the beta-1, 4-endo-xylanase gene BsxynA are researched The enzyme activity of the bacillus safensis xylanase reaches 83.913 U / mL, the bacillus safensis xylanase is expected to be subjected to gene mutation through mutation breeding such as physical (such as ultraviolet rays and gamma rays) or chemical (such as nitrosoguanidine and diethyl sulfate) mutagenic agent treatment, and bacillus safensis mutants with higher enzyme activity are directionally screened. For example, ultraviolet mutagenesis can cause random mutation of the DNA of the microorganism, change the expression of the gene or the structure of the zymoprotein, and possibly increase the xylanase yield or enhance the xylanase activity. The produced BsXynA mainly promotes the hydrolysis of beech xylan, so that xylobiose (X2) and xylotetraose (X4) are generated, and xylose is not generated. In addition, the BsXynA significantly improves the digestive performance of the animal feed, and can increase the xylose content in the feed, promote the nutrient absorption of animals and reduce the production cost.

A Penicillium cyclopium strain capable of degrading crop straw fibers efficiently and application thereof are provided. The provided induces mutagenesis of a Penicillium cyclopium strain MP-03 (2554-2) (CGMCC No. 41542) using a nitrosoguanidine method and obtains a mutant strain ΔMP-03 (455-1) (CGMCC No. 41541) with enhanced ability to degrade corn straw. By optimizing a nitrogen-to-carbon ratio of culture medium, culture time, temperature, and a pH range for high enzymatic activity, the mutant strain 455-1 significantly enhances the degradation of corn straw, and endoglucanase and exoglucanase activities in corn straw compared with the non-mutant strain 2554-2. The provided optimizes the conditions for scale-up culture of the mutant strain 455-1, and develops the organic-coupled cultivation technology that integrates a fermentation suspension of the mutant strain 455-1, corn straw and organic fertilizer, which improves the growth, root development and photosynthetic efficiency of greenhouse vegetable, and resistance to the soil-borne oomycete diseases.

The invention belongs to the field of bioengineering, and relates to a method for screening high-yield butanol strains through cyclic compound mutation and application of the high-yield butanol strains, in order to increase the gene diversity of starting strains, the method comprises the following steps: equivalently mixing a plurality of clostridium acetobutylicum strains as the starting strains; taking compound mutagenesis of nitrosoguanidine-acridine orange-nitrosoguanidine-lithium chloride as a cycle, repeating for three cycles, and continuously domesticating the mutagenic flora by gradually increasing the butanol concentration of the culture medium, so as to obtain the mutant flora with high butanol tolerance. And carrying out single colony separation on the mutant flora with high butanol tolerance, measuring the butanol content through fermentation, and screening to obtain the high-yield butanol strain.

This invention discloses a strain of *Bacillus coagulans* that facilitates cell recovery and its application in lactic acid fermentation, belonging to the fields of microbiology and fermentation engineering technology. This invention isolates a batch of thermoresistant bacteria from spoiled milk. After small-scale cell culture, a flocculant is added to observe sedimentation. The strain with the fastest sedimentation rate is selected, and *Bacillus coagulans* is identified among them. Further screening yields a strain, XQ20249, with rapid cell sedimentation and high optical purity of L-lactic acid produced during fermentation. Further mutagenesis using nitrosoguanidine and screening yields mutant strains with even faster cell sedimentation. Among them, mutant strain LL08 shows a significant increase in flocculation and exhibits faster growth and lactic acid fermentation rates than other mutant strains under lactic acid fermentation conditions. When strain LL08 is used for lactic acid fermentation, the cells can be collected by sedimentation after fermentation for secondary fermentation, significantly reducing the amount of organic nitrogen source used.

The invention relates to the technical field of tetramethylpyrazine strain breeding, in particular to a tetramethylpyrazine strain high-throughput breeding device. Comprising a breeding box; a door plate is rotatably mounted on the breeding box, a handle is fixedly connected to the side wall of the door plate, a magnetic strip is embedded in the upper portion of the breeding box, a control panel is mounted on the side wall of the breeding box, ultraviolet lamps which are symmetrically distributed are mounted on the side wall in the breeding box, and a mounting frame is mounted at the bottom in the breeding box. And a mounting groove is formed in the mounting frame. The adding amount of nitrosoguanidine is accurately controlled through the quantitative assembly, the concentration and dosage of a mutagenic agent fed into each adding tank are consistent, the problem that the adding amount of nitrosoguanidine in traditional chemical mutagenesis is difficult to control in a standardized mode is solved, the difference of mutagenesis effects of strains in different batches is effectively avoided, the stability of the positive mutation rate of the strains is guaranteed, and the yield of the strains is increased. And the reliability of chemical mutagenesis is improved.

This application belongs to the field of breeding technology and specifically provides a method for mutagenesis breeding of Porphyra haitanensis, comprising the following steps: 1) irradiating the coniferous bodies of Porphyra haitanensis with ultraviolet light; 2) treating the irradiated coniferous bodies with a mutagen comprising nitrosoguanidine and a slow-release solution comprising bleomycin and bleomycin; and 3) screening the mutagenized coniferous bodies to obtain mutants, which are then cultured to obtain thallus. This breeding method has the advantages of high efficiency, high mutation rate, and good specificity.