Abstract: The disclosure discloses genetically engineered bacteria producing lacto-N-neotetraose and a production method thereof, and belongs to the fields of metabolic engineering and food biotechnology. To solve the problem of low yield of lacto-N-neotetraose produced by a microbial method in the prior art, through exogenous expression of lgtA and lgtB, reasonable combination and regulation of overexpression of lacY, pgm, galE, galT and galK in a lacto-N-neotetraose synthesis pathway, knockout of lacZ expression in an Escherichia coli host, and optimization of a carbon source in the culture process, the disclosure achieves the objectives of regulating the carbon flux of a metabolic pathway and improving the yield of lacto-N-neotetraose. In a shake flask experiment, the yield of lacto-N-neotetraose produced by E. coli increased from 304 mg/L to 1031 mg/L, laying a foundation for industrial production of the lacto-N-neotetraose.

Abstract: The present disclosure discloses a strain producing D-allulose 3-epimerase and application thereof, and belongs to the technical field of bioengineering. The present disclosure provides a method for improving the expression of D-allulose 3-epimerase by screening promoters and optimizing RBS thereof. The recombinant Bacillus subtilis constructed using thevectors pP43NMK-hag and pP43NMK-hag-RBS4 provided by the present disclosure improves the enzyme activity of a target gene D-allulose 3-epimerase, and theenzyme activities in shake flasks upon transformation are 1.30 times and 1.69 times that of an original vector. The present disclosure further provides a non-antibiotic resistance vector and a non-antibiotic resistance recombinant B. subtilis strain. Using the non-antibiotic resistance strain B. subtilis 1A751-dal-/pP43NMK-hag-RBS4-dpe-dal provided by the present disclosure, the highest fermentation enzyme activity in a shake flask is 24.72 U/mL, and the enzyme activity in a fermenter is 714.8 U/mL.

Abstract: A rigid-collision-free transmission line spacer clamp connection structure includes a spacer frame, rotating joint rubber gaskets and spacer connecting clamps, the spacer frame being uniformly provided with a plurality of rotating joint slots that are rotationally connected with spacer connecting clamps, adopting a “spacer frame, rotating joint rubber gasket and spacer connecting clamp body tail” connection form. The spacer connecting clamp has a connecting rod and a clip, the connecting rod being provided with a connecting rod mounting hole at a rear end and the rotating joint slot being provided with a rotating joint rubber gasket and a spacer connecting clamp rotating shaft therein. The spacer connecting clamp rotating shaft penetrates through the connecting rod mounting hole and a rotating joint rubber gasket mounting hole.

Abstract: A rigid-collision-free transmission line spacer clamp connection structure includes a spacer frame, rotating joint rubber gaskets and spacer connecting clamps, the spacer frame being uniformly provided with a plurality of rotating joint slots that are rotationally connected with spacer connecting clamps, adopting a “spacer frame, rotating joint rubber gasket and spacer connecting clamp body tail” connection form. The spacer connecting clamp has a connecting rod and a clip, the connecting rod being provided with a connecting rod mounting hole at a rear end and the rotating joint slot being provided with a rotating joint rubber gasket and a spacer connecting clamp rotating shaft therein. The spacer connecting clamp rotating shaft penetrates through the connecting rod mounting hole and a rotating joint rubber gasket mounting hole.