Abstract: Provided are a recombinant strain with modified gene BBD29_14900, and a method for constructing the same and use thereof, with the production of L-glutamic acid as a specific application. Further provided is a method for introducing a point mutation into the BBD29_14900 gene coding sequence in Corynebacterium or improving the expression thereof. The method can cause a bacterial strain with the mutation to increase the fermentation yield of glutamic acid. The point mutation involves a mutation of the base at position 1114 in the sequence of the BBD29_14900 gene from guanine (G) to adenine (A), and thus a substitution of aspartic acid at position 372 in the coded corresponding amino acid sequence with asparagine.

Abstract: Disclosed are strain having enhanced L-glutamic acid production capacity, and method for constructing the same and use thereof. A nucleotide sequence is provided by introducing a point mutation to a wild-type BBD29-00405 gene in Corynebacterium glutamicum so that the base at position 597 of SEQ ID NO: 1 is mutated from guanine (G) into adenine (A). Also provided is a recombinant strain obtained by introducing the polynucleotide sequence into L-glutamic acid-producing Corynebacterium glutamicum, the recombinant strain comprising a BBD29-00405 gene containing a point mutation. Compared with an unmodified strain, the resulting strain facilitates production of L-glutamic acid at a higher concentration.

Abstract: A recombinant strain with modified gene BBD29_11265 and a method for constructing the same are provided. The recombinant strain is a bacterium that generates L-glutamic acid, and has an improved expression of a polynucleotide encoding an amino acid sequence of SEQ ID NO: 3 or a homologous sequence thereof; the improved expression can be having a point mutation in, and an enhanced expression of the polynucleotide encoding an amino acid sequence of SEQ ID NO: 3 or a homologous sequence thereof. A genetically engineered bacterium in which the base at position 70 in the BBD29_112665 gene sequence is mutated to adenine from guanine, causing alanine at position 24 in the coded corresponding amino acid sequence to be substituted with threonine, and an engineered bacterium overexpressing the BBD29_112665 gene or BBD29_11265G70A gene are constructed in the present invention, facilitating an increase in the production and conversion rate of L-glutamic acid.

Abstract: Taking Corynebacterium glutamicum YP97158 as the starting bacterium, introducing site-directed mutation and/or expression enhancement in the coding region of its NCgl1089 gene, the coding region of NCgl0761 gene, and/or the coding region of ptsS gene, the obtained mutant gene and the recombination comprising said gene has high-efficiency L-amino acids production capacity, which greatly increases the output of L-amino acids, and the strain has good stability, which reduces the production cost as an L-amino acids production strain.

Abstract: A bacterium for producing L-amino acid has improved expression of a polynucleotide encoding a protein represented by SEQ ID NO:3 and improved expression of a polynucleotide encoding a protein represented by SEQ ID NO:31, and/or has mutations in bases at positions ?45 bp and ?47 bp of a promotor region represented by SEQ ID NO:57. A polynucleotide, encodes proteins and can be included in a recombinant vector, which can be included in a recombinant strain. These are useful in a method for producing L-amino acid. The polynucleotide encodes a protein which is represented by SEQ ID NO:3 and has arginine at position 334 substituted by a terminator or encodes a protein which is represented by SEQ ID NO:31 and has tyrosine at position 592 substituted by phenylalanine, or is formed by mutations in bases at positions ?45 bp and ?47 bp of a promotor region represented by SEQ ID NO:57.

Abstract: An Escherichia coli-based kdtA-gene-modified recombinant strain, a construction method therefor and use thereof are provided. A mutant gene obtained by subjecting a wild-type kdtA gene (ORF sequence is shown in a sequence 73556-74833 in GenBank accession No. CP032667.1), a wild-type spoT gene (ORF sequence is shown in a sequence 3815907-3818015 in GenBank accession No. AP009048.1) and a wild-type yebN gene (ORF sequence is shown in a sequence 1907402-1907968 in GenBank accession No. AP009048.1) of an E. coli K12 strain and a derivative strain thereof (such as MG1655 and W3110) to site-directed mutagenesis, and a recombinant strain obtained therefrom can be used for the production of L-threonine. Compared with an unmutated wild-type strain, the obtained strain can produce L-threonine with a higher concentration and has good strain stability, and also has lower production cost as an L-threonine production strain.

Abstract: The present disclosure discloses an Escherichia coli-based genetically-modified recombinant strain, a construction method therefor and use thereof. A mutant gene obtained by subjecting a wild-type deoB gene (ORF sequence is shown in a sequence 3902352-3903575 in GenBank accession No. CP032667.1) and a wild-type rhtA gene promoter sequence PrhtA (shown in a sequence 850520-850871 in GenBank accession No. AP009048.1) of an E. coli K12 strain and a derivative strain thereof (such as MG1655 and W3110) to site-directed mutagenesis, and a recombinant strain obtained therefrom can be used for the production of L-threonine, and compared with an unmutated wild-type strain, the obtained strain can produce L-threonine with a higher concentration and has good strain stability, and also has lower production cost as an L-threonine production strain.

Abstract: A surfactant that changes the wettability of tight sandstone and its preparation method and application. By adding the aqueous phase solution into the oil phase solution, and under the action of the emulsifier, a uniformly dispersed phase is achieved. Then adding initiator, stirring and raising the temperature, reacting the reaction at the temperature to obtain a colorless and transparent liquid, i.e., high polymer. At room temperature, adding fluorocarbon surfactant and biosurfactant and stirring was continued for 4 hours to obtain a surfactant that changes the surface wettability of tight sandstone. The surfactant of the present invention can reduce the oil-water interfacial tension, transform the oil-wet surface into water-wet surface, which reduces the adhesion of oil droplets to rock surface and improves the flowability of crude oil in the original stratum, and improves the recovery of low-permeability reservoir.

Abstract: A surfactant that changes the wettability of tight sandstone and its preparation method and application. By adding the aqueous phase solution into the oil phase solution, and under the action of the emulsifier, a uniformly dispersed phase is achieved. Then adding initiator, stirring and raising the temperature, reacting the reaction at the temperature to obtain a colorless and transparent liquid, i.e., high polymer. At room temperature, adding fluorocarbon surfactant and biosurfactant and stirring was continued for 4 hours to obtain a surfactant that changes the surface wettability of tight sandstone. The surfactant of the present invention can reduce the oil-water interfacial tension, transform the oil-wet surface into water-wet surface, which reduces the adhesion of oil droplets to rock surface and improves the flowability of crude oil in the original stratum, and improves the recovery of low-permeability reservoir.

Abstract: According to embodiments of the present invention, a detector module is provided. The detector module includes: a chip configured to receive at least one specimen; a first light-emitting diode configured to illuminate the at least one specimen; and a first photodetector configured to detect light emitted from the at least one illuminated specimen. According to further embodiments, a detection system is provided. The detection system includes: a detector module; a control module in electrical communication with the detector module; and a pump module configured to collect a sample and transfer the sample to a chip of the detector module.

Abstract: An optical fiber strain sensor, a method of fabricating the same, and a method of sensing strain. The method of strain sensing comprises providing an optical fiber having a fiber Bragg grating (FBG) formed therein; subjecting the optical fiber to a strain inducing force such that a grating period in a first portion of the FBG compresses and a grating period in a second portion of the FBG extends; and optically interrogating the FBG to determine a measure of a change in bandwidth of the FBG as a result of the compression and extension of the grating periods in the first and second portion respectively; whereby the measure of the change in the bandwidth is representative of the strain induced.

Abstract: An optical fiber strain sensor, a method of fabricating the same, and a method of sensing strain. The method of strain sensing comprises providing an optical fiber having a fiber Bragg grating (FBG) formed therein; subjecting the optical fiber to a strain inducing force such that a grating period in a first portion of the FBG compresses and a grating period in a second portion of the FBG extends; and optically interrogating the FBG to determine a measure of a change in bandwidth of the FBG as a result of the compression and extension of the grating periods in the first and second portion respectively; whereby the measure of the change in the bandwidth is representative of the strain induced.