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: 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: The present invention discloses a copper-zinc-aluminum-iron single crystal alloy material having an ultra-large grain structure of 5-50 cm grade, obtained by annealing an as-cast alloy having a polycrystalline structure through a single phase region of 800-960° C. for 2-105 h, where the as-cast alloy includes, by weight percentage, 62-82% of copper, 6-29% of zinc, 5-12% of aluminum, and 2-5% of iron. In the present invention, the alloy compositions have an essential difference and are a copper-zinc-aluminum-iron quaternary alloy, and the iron element is an indispensable alloying element. The preparation process of the present invention is extremely simple and very easy to implement and has a very good application prospect.

Abstract: The present invention discloses a copper-zinc-aluminum-iron single crystal alloy material having an ultra-large grain structure of 5-50 cm grade, obtained by annealing an as-cast alloy having a polycrystalline structure through a single phase region of 800-960° C. for 2-105 h, where the as-cast alloy includes, by weight percentage, 62-82% of copper, 6-29% of zinc, 5-12% of aluminum, and 2-5% of iron. In the present invention, the alloy compositions have an essential difference and are a copper-zinc-aluminum-iron quaternary alloy, and the iron element is an indispensable alloying element. The preparation process of the present invention is extremely simple and very easy to implement and has a very good application prospect.