Abstract: Recombinant strains are obtained for the production of allulose, allose, and allitol by regulating intracellular glucose metabolism, reducing the enzyme activity of fructose 6-phosphate kinase, and enhancing the enzyme activities of glucokinase and glucose-6-phosphate isomerase, allulose 6-phosphate 3-epimerase, allulose 6-phosphate phosphatase, fructose permease and fructokinase, and optionally enhancing the enzyme activities of ribose 5-phosphate isomerase, allose 6-phosphate phosphatase, ribitol dehydrogenase, glycerol permease, glycerol dehydrogenase, and dihydroxyacetone kinase. A method for producing allulose and allose is an extracellular multienzyme cascade method. Multienzyme cascade catalysis and fermentation are coupled to improve the conversion rate of starch sugar or sucrose to the synthesized allulose.

Abstract: Provided are a Bacillus subtilis genetically engineered bacterium for producing tagatose and a method for preparing tagatose. The genetically engineered bacterium comprises constructing thermostable ?-glucan phosphorylases, thermostable glucose phosphomutases, thermostable glucose phosphate isomerases, thermostable 6-tagatose phosphate epimerases, and thermostable 6-tagatose phosphate phosphatases which are independently expressed or co-expressed. The usage of the genetically engineered bacterium can effectively convert starch into tagatose. Compared with existing methods for producing tagatose, the method has advantages such as suitability for whole-cell recycling, high safety, high yield, simple production process, low cost, and easiness in large-scale preparation.

Abstract: Provided are the immobilization of multiple enzymes on the basis of an artificial oil body and an application thereof in the preparation of tagatose. Specifically, an artificial oil body is used to mix an expressed fusion protein of target protease-oil body protein with an oil body, which then undergoes an ultrasonic treatment; the fusion protein is anchored to the surface of the oil body by means of the specific hydrophobicity of a human protein to form an artificial oil body containing the target protease, so that the purification and immobilization of enzymes can be completed simultaneously. The immobilized multiple enzymes that can be used for tagatose production utilize an artificial oil body as an immobilized enzyme substrate, which significantly improves the stability of the immobilized enzymes, reduces the production cost of the current enzymatic preparation of tagatose, and has a simple preparation process.

Abstract: Provided are a recombinant microorganism modified by means of genetic engineering and an application of the recombinant microorganism in production of tagatose, a preparation method for the recombinant microorganism, a tagatose production strain and a tagatose production method. According to the recombinant microorganism, the tagatose is produced by taking glucose as a substrate or taking glycerol and glucose as substrates; the efficiency of conversion and production of tagatose by means of the recombinant microorganism is high, and a multi-enzyme purification process step is not needed.

Abstract: Disclosed is a new tagatose 6-phosphate 4-epimerase, which is capable of converting fructose 6-phosphate into tagatose 6-phosphate and vice versa. Also disclosed is an application of the enzyme in tagatose production.

Abstract: Recombinant strains are obtained for the production of allulose, allose, and allitol by regulating intracellular glucose metabolism, reducing the enzyme activity of fructose 6-phosphate kinase, and enhancing the enzyme activities of glucokinase and glucose-6-phosphate isomerase, allulose 6-phosphate 3-epimerase, allulose 6-phosphate phosphatase, fructose permease and fructokinase, and optionally enhancing the enzyme activities of ribose 5-phosphate isomerase, allose 6-phosphate phosphatase, ribitol dehydrogenase, glycerol permease, glycerol dehydrogenase, and dihydroxyacetone kinase. A method for producing allulose and allose is an extracellular multienzyme cascade method. Multienzyme cascade catalysis and fermentation are coupled to improve the conversion rate of starch sugar or sucrose to the synthesized allulose.

Abstract: Disclosed is a new tagatose 6-phosphate 4-epimerase, which is capable of converting fructose 6-phosphate into tagatose 6-phosphate and vice versa. Also disclosed is an application of the enzyme in tagatose production.

Abstract: This application discloses novel vacuum break devices useful in automatic vacuum flushing systems. The vacuum break devices are capable of rapidly breaking the vacuum in a storage tank of a sewer line, thus enabling efficient flushing of sediments and cleaning of the sewer system. The invention also provides automatic vacuum flushing systems comprising these novel rapid vacuum break devices and methods thereof for sewer or storage tank sediment cleaning in urban drainage systems.

Abstract: This application discloses novel vacuum break devices useful in automatic vacuum flushing systems. The vacuum break devices are capable of rapidly breaking the vacuum in a storage tank of a sewer line, thus enabling efficient flushing of sediments and cleaning of the sewer system. The invention also provides automatic vacuum flushing systems comprising these novel rapid vacuum break devices and methods thereof for sewer or storage tank sediment cleaning in urban drainage systems.