Abstract: The invention provides an Escherichia coli for synthesizing L-valine, a construction method and use thereof. The Escherichia coli of the invention is designated as Escherichia coli W3110 and was deposited in China Center for Type Culture Collection (Address: Bayi Road, Wuchang District, Wuhan City, Hubei Province) under the Accession No. CCTCC M 2022293 on Mar. 18, 2022. The recombinant Escherichia coli takes Escherichia coli as a starting strain, and a transcription regulation factor is overexpressed to obtain a recombinant Escherichia coli. The recombinant Escherichia coli for synthesizing L-valine of the invention is fermented in a 5 L fermentor with trace dissolved oxygen to test strains, the yield of L-valine reaches 112 g/L, and the OD of the bacterium is 104.

Abstract: The present disclosure provides a Bacillus subtilis strain, a recombinant B. subtilis strain and use thereof, belongs to the technical field of microbial fermentation. B. subtilis strain RF1-6 provided by the present disclosure is a mutant strain with the highest riboflavin yield screened by gene modification and mutagenesis using a high riboflavin-producing strain RF1 as a starting strain, deposited at China Center for Type Culture Collection (CCTCC) under accession number M 2022565. Riboflavin yield can be increased by 22.8% compared with that of the high riboflavin-producing strain RF1.

Abstract: A first electronic device determines that a first trigger condition is satisfied, sends a first instruction to enable a first sound wave transmitter to send a first sound wave signal, and sends a second instruction to enable a second sound wave transmitter to send a second sound wave signal. A second electronic device sends a third instruction to enable a first sound wave receiver to receive the first sound wave signal and the second sound wave signal, calculates a first receiving start moment and a second receiving start moment, obtains first location information, determines second location information based on the first receiving start moment, the second receiving start moment, and the first location information, and sends the second location information to the first electronic device. The first electronic device updates third location information by using the second location information.