38 results about "Spontaneous mutation" patented technology

The present invention includes compositions and methods for making and using halophilic cyanobacterium comprising a spontaneous mutation causing constitutive cellulose biosynthesis, whereby the cyanobacterium is capable of producing cellulose in brine. The compositions and methods of the present invention may be used as a new global crop for the manufacture of cellulose, CO2 fixation, for the production of alternative sources of conventional cellulose as well as a biofuel and precursors thereof.

A method for determining mutation load in a somatic cell is determined by mutation analysis of the p53 gene. The p53 gene has been found to be a useful indicator of predisposition to spontaneous mutations or prior carcinogen exposure. Cells that contain mutated p53 tend to accumulate the mutant protein. Thus, DNA from a cell identified by p53 accumulation is amplified and the amplification product further analyzed for mutations in the p53 gene.

The present invention discloses new live attenuated strains for oral immunization against cholera that are provided in freeze dried formulations for long term storage and administration to humans. These strains combine the two most important properties of live attenuated cholera vaccine candidates. One such property is being well tolerated by people ingesting them. This was achieved by virtue of mutations already described in the art. The second property is having enhanced environmental safety due to the absence of VGJΦ DNA in their genomes and also due to null mutations in the mshA gene or other spontaneous mutations conducive to the lack of MSHA type IV fimbria on the bacterial surface. This was done envisioning that VGJΦ is a filamentous phage able to recombine with CTXΦ and disseminate the cholera toxin genes. This VGJΦ phage as well as the VGJΦ-CTXΦ recombinants uses the MSHA fibers as receptor. Being devoid of MSHA fimbria the vaccine candidates are protected from acquiring CTXΦ from the recombinant hybrid VGJΦ-CTXΦ. Being devoid of VGJΦ, the vaccine candidates are impaired in the dissemination of CTXΦ, via VGJΦ.

The invention relates to a method for separating and detecting a spontaneous mutation gene based on agarose gel denaturation and renaturation and biotin affinity adsorption, which belongs to the technical field of biology, and relates to a method for separating and detecting a mutation gene. The method comprises the following steps of: marking wild deoxyribonucleic acid (DNA) fragments by using biotin, mixing the biotin-marked wild DNA fragments and DNA fragments to be detected, and performing denaturation and renaturation, wherein at the moment, DNA fragments which contain mutation sites cannot form heteroduplex DNA molecules because the biotin-marked wild DNA fragments with the same migration rate as the DNA fragments are not hybridized with the DNA fragments, DNA fragments which do notcontain the mutation sites are hybridized with the corresponding biotin-marked wild DNA fragments to form the heteroduplex DNA molecules, and the heteroduplex DNA molecules carry biotin marks; and adsorbing and recovering the molecules which carry the biotin marks by using streptavidin magnetic beads to separate the DNA fragments which contain the mutation sites. Compared with the conventional method, the method is simpler and more convenient and sensitive, can be used for accurately identifying and detecting the mutation sites, and has high reliability.

Belonging to the technical field of bioengineering, the invention relates to a genetic engineering strain producing succinic acid and a method for production of succinic acid by fermenting the strain, particularly a recombinant strain efficiently utilizing cane sugar and molasses to grow and produce succinic acid. The genetic engineering strain producing succinic acid is classified and named as Escherichia coli BA501, and has a preservation registration number of CCTCC NO:M2014014. The construction process of the strain mainly includes: taking Escherichia coli AFP111 that lacks lactate dehydrogenase gene and pyruvate formate lyase activity and has the chromosome ptsG gene undergoing spontaneous mutation as the starting strain, expressing exogenous sucrose permease, sucrose hydrolase and fructokinase genes, and then carrying out continuous domestication cultivation to obtain the strain efficiently utilizing cane sugar and molasses to grow and produce succinic acid. Thus, the synthesis efficiency of succinic acid is greatly improved. The fermentation method adopts a two-stage fermentation way, in the aerobic stage the biomass is improved oxygen, and in the anaerobic stage, fermentation and acid production are achieved.

A natural yeast extract which is rich in glutamic acid and therefore has an impact at first taste. Further, provided is a yeast extract which is also rich in 5′-guanylic acid or 5′-inosinic acid and therefore has strong umami. Further, provided is a yeast mutant capable of accumulating a large amount of glutamic acid, glutamine and ribonucleic acid for obtaining such a yeast extract. A yeast mutant to which resistance to organic acids and analogues thereof has been imparted by inducing spontaneous mutation, accumulates a significant amount, i.e., 10% by weight or more of the total of free glutamic acid and glutamine in the cell, and further accumulates 5% by weight or more of a ribonucleic acid. The yeast extract produced by using this strain contains 20% by weight or more of L-glutamic acid, and further contains 3% by weight or more of 5′-IG.

The invention concerns methods for the development of mutant animals, including genetically engineered animals and those carrying spontaneous mutations, as human disease models. In particular, the invention provides an integrated technology, including rigorous specifications and quality control, for the development of animal models that can serve as a living assay system, useful in biomedical research and in the development of human therapeutics.

The invention relates to a method for constructing succinic-acid-producing Escherichia coli and the application of Escherichia coli. The method comprises the following steps: taking Escherichia coli which lacks of activities of lactate dehydrogenase genes and pyruvate formate-lyase genes and in which a ptsG chromosome of a phosphotransferase system is subjected to spontaneous mutation as an original strain, and constructing recombinant Escherichia coli containing corynebacterium glutamicum NCg12130. According to the recombinant Escherichia coli constructed by the method disclosed by the invention, the secretion ability of succinic acid is obviously improved, and the bacterial growth, sugar consumption and succinic acid production capacity in the whole process are obviously enhanced. The method disclosed by the invention provides a novel excellent transport protein for enhancing the capacity of transporting the succinic acid by the Escherichia coli and further provides a new way for enhancing the succinic acid secretion performance.

The invention discloses a cordyceps militaris rejuvenation breeding process. The concrete steps are as follows: carrying out activation culture of a degraded cordyceps militaris strain; inoculating the activated cordyceps militaris strain in a shake flask culture medium for culturing, and the inoculating the strain on a wheat or rice culture medium for culturing; selecting fruiting bodies, cuttingoff tips, hanging the tips on the cup of the cultivation culture medium for culturing until spores on the surface of the culture medium are germinated thoroughly, removing the fruiting body tips, andcontinuing to culture the tips for 30-40 d; and picking and drying the mature cordyceps militaris, detecting cordycepin, the main active ingredient of the cordyceps militaris, and using the cordycepsmilitaris as an original cultivation species until the traits are stable. The cordyceps militaris rejuvenation breeding process does not need to use a spore collector, is simplified in operation andsaves breeding cost. Furthermore, since the process is monospore purification rejuvenation, the purity of the strain can be guaranteed. The excellent strains with stable traits are orientedly screenedas the original cultivation species, and are suitable for the rejuvenation of strains degraded by spontaneous mutation and inappropriate environmental factors.

The invention discloses a multiplex-PCR detection method for a single sperm. The method comprises the steps that A, sperms are pretreated; B, micromanipulation is performed to pick up a single sperm; C, the sperm is subjected to multiplex-PCR detection. The multiplex-PCR detection method for a single sperm breaks through the limitation, only targeting female eggs and embryos, of past genetic disease gene detection on micro-cells and makes it possible for analysis of whether a male germ cell is a chimera. Through the method, very rare spontaneous mutation which only exists in a single sperm and cannot be detected in a somatic cell or sperm groups can be detected, auxiliary diagnosis analysis of de novo mutation can be performed on a paternal age effect series genetic disease caused by de novo mutation of a paternal germ cell, and on this basis, the risk of birth of a child patient with the genetic disease can be prevented and interdicted in combination with the preimplantation genetic diagnosis technology.

The invention belongs to the technical field of plant genetic engineering, and particularly relates to rapid mapping and cloning method for plant spontaneous mutation genes bridged by a neutral mutant. The invention aims to overcome the defects in the prior art, and the neutral mutant produced by mutagenesis of an ethylmethane sulfonate (EMS) mutagenic agent composition is utilized to rapidly mapthe spontaneous mutation genes. Under the same genetic background, the neutral mutant (namely, no macroscopic phenotypic variation) produced by mutagenesis of the EMS mutagenic agent composition is hybridized with a spontaneous mutant to obtain F1, and selfing is continued to obtain an F2 generation. By performing screening and hybrid sequencing of extremely recessive phenotypic single plants in an F2 population, combining with EMS mutated neutral mutant sequencing data, and utilizing a bioinformatics method, the mutation genes are rapidly mapped. Compared with known methods, the rapid mappingand cloning method has the outstanding advantages of high screening efficiency, short consumed time, low cost and the like. The rapid mapping and cloning method can be used for rapid cloning of the spontaneous mutation genes.

The invention discloses a plasmid for improving spontaneous mutation frequency of bacillus subtilis. The plasmid is selected from any one of a PUS20D9M, a PUS20XP1 and a PUS20XP2; wherein the plasmid pUS20D9M has a sequence as shown in SEQ ID NO. 1, the plasmid pUS20XP1 has a sequence as shown in SEQ ID NO. 2, and the plasmid pUS20XP2 has a sequence as shown in SEQ ID NO. 3. Bacillus subtilis is an important microorganism. Many breeding works need to improve gene mutation frequency of bacillus subtilis. However, an ideal method for controlling spontaneous mutation frequency of bacillus subtilis does not exist at present. According to the invention, by virtue of a CRISPRi technology and a method for overexpressing error-prone DNA polymerase, the spontaneous mutation frequency of a host is improved (as high as 5128 times). The whole operation can be realized through transformation and elimination of plasmids, and gene knockout of a host is not needed.

Belonging to the technical field of bioengineering, the invention relates to a genetic engineering strain producing succinic acid and a method for production of succinic acid by fermenting the strain, particularly a recombinant strain efficiently utilizing cane sugar and molasses to grow and produce succinic acid. The genetic engineering strain producing succinic acid is classified and named as Escherichia coli BA501, and has a preservation registration number of CCTCC NO:M2014014. The construction process of the strain mainly includes: taking Escherichia coli AFP111 that lacks lactate dehydrogenase gene and pyruvate formate lyase activity and has the chromosome ptsG gene undergoing spontaneous mutation as the starting strain, expressing exogenous sucrose permease, sucrose hydrolase and fructokinase genes, and then carrying out continuous domestication cultivation to obtain the strain efficiently utilizing cane sugar and molasses to grow and produce succinic acid. Thus, the synthesis efficiency of succinic acid is greatly improved. The fermentation method adopts a two-stage fermentation way, in the aerobic stage the biomass is improved oxygen, and in the anaerobic stage, fermentation and acid production are achieved.

A new and distinct Hybrid Tea rose plant is provided which forms attractive blossoms that are hot pink in coloration. The new variety is a spontaneous mutation of unknown causation of the ‘Meilavio’ variety (U.S. Plant Pat. No. 10,845) that forms vivid red blossoms. The blossoms are fully double, long lasting, and very quartered in the sense the petals of the fully opened blossoms tend to be arranged in a plurality of zones when viewed from above. The vegetation is strong and vigorous and the growth habit is erect. Many large thorns are exhibited. The foliage is very decorative, dark green, and semi-glossy and contrasts nicely with the hot pink blossom coloration. Good resistance to Black Spot and Powdery Mildew is displayed. The new variety is well suited for providing attractive ornamentation in the garden.

A new and distinct variety of climbing rose plant is provided which forms in abundance on a substantially continuous basis attractive clusters of semi-double informal clear yellow blossoms having approximately ten petals on average. The new variety is a spontaneous mutation of unknown causation of the ‘Radsun’ variety (U.S. Plant Pat. No. 13,063). The climbing growth habit can be readily distinguished from the free-standing growth habit of the ‘Radsun’ variety. Vigorous vegetation is formed. The foliage is dense medium green with a satin finish. Excellent resistance to Black Spot is displayed. Attractive dense ornamentation in the form of foliage and blossoms is made possible when the new variety is grown on a support.

The invention belongs to the technical field of biology, and particularly relates to a genetic manipulation method for manually controlling a spontaneous mutation rate of bacillus subtilis and application thereof. The genetic manipulation method comprises the following steps: regulating and controlling an operon MutSL which is responsible for a mismatch repair system of the bacillus subtilis by axylose induced promoter and repressor protein, and establishing recombinant plasmids in corresponding inducible expression; integrating the recombinant plasmids to a bacterial strain genome by utilizing Spizizen double exchange, and carrying out positive-negative selection, thus obtaining objective engineering strains; regulating different expression levels of the operon MutSL of the mismatch repair system through different xylose addition concentration, thus realizing manual control on the spontaneous mutation rate of the bacillus subtilis.

The invention discloses an anti-bacteriophage aspartase variant production bacterium, a breeding method and an application thereof. The present invention carries out continuous spontaneous mutation breeding on the aspartase variant producing bacteria pL181 which is easily polluted by phages, and then utilizes the low-energy ion implantation mutagenesis method to efficiently breed a strain of aspartase with phage resistance Acidase variant producing bacteria Escherichia coli CGMCC NO.18005. The strain not only has the resistance to bacteriophage (CGMCC NO.17999), but also has 31% higher enzyme activity than the original strain pL181. While improving the enzyme-producing ability of the producing bacteria, the present invention fundamentally solves the difficult problem that β-alanine is easily infected by phages in the production, and improves the economic benefits of β-alanine production enterprises.

The invention discloses a gene editing tool, a preparation method thereof and a multi-round gene editing method, and belongs to the technical field of gene engineering. The problem that an existing multi-round gene editing method wastes time and labor is solved. The invention provides a gene editing tool, which comprises the following three sgRNA expression parent plasmids: pRock series mother plasmids, pPaper series mother plasmids and pScissors series mother plasmids, wherein each mother plasmid can express sgRNA used for editing a target gene and can also express sgRNA targeting one of theother two mother plasmids. In the process of implementing gene editing, when the gene editing plasmids constructed by the three mother plasmids are recycled, the gene editing plasmids which are firstly used in host cells or the selection markers are eliminated by the gene editing plasmids which are later used. According to the method, the editing period is shortened, the multi-round gene editing speed is increased, and the possibility of spontaneous mutation of the genome can be reduced due to fewer culture times.

A new and distinct variety of climbing shrub rose plant is provided. The new plant is a spontaneous mutation of unknown causation of the ‘Meiviolin’ variety (U.S. Plant Pat. No. 6,892). Attractive near white long-lasting very double blossoms having an ancient rose configuration are formed on a substantially continuous basis. Vigorous medium green semi-glossy foliage is formed that contrasts well with the near white blossom coloration. Good resistance to Black Spot and good tolerance to frost are displayed. The new variety is particularly well suited for providing attractive ornamentation in the landscape. It can be grown to advantage on a trellis, lamppost or gazebo.