The disclosure discloses an Aspergillus niger engineered strain for reducing byproduct fumaric acid in a fermentation process of L-malic acid. The Aspergillus niger engineered strain is an Aspergillus niger engineered strain in which a fumarate hydratase gene fum is knocked out. The disclosure overcomes the defects in the prior art, in the current process of producing malic acid through fermentation of Aspergillus niger, byproduct fumaric acid can be accumulated with the generation of malic acid so as to cause the improved cost of the subsequent malic acid purification process. The disclosure provides an Aspergillus niger engineered strain in which a fum gene is knocked out and a method for greatly reducing byproduct fumaric acid in the fermentation production of Aspergillus niger.

The disclosure discloses an Aspergillus niger engineered strain for reducing byproduct fumaric acid in a fermentation process of L-malic acid. The Aspergillus niger engineered strain is an Aspergillus niger engineered strain in which a fumarate hydratase gene fum is knocked out. The disclosure overcomes the defects in the prior art, in the current process of producing malic acid through fermentation of Aspergillus niger, byproduct fumaric acid can be accumulated with the generation of malic acid so as to cause the improved cost of the subsequent malic acid purification process. The disclosure provides an Aspergillus niger engineered strain in which a fum gene is knocked out and a method for greatly reducing byproduct fumaric acid in the fermentation production of Aspergillus niger.

The present invention provides a method for producing an alkaline phosphatase (ALP), the method including a step of: culturing an Aspergillus transformant capable of producing the ALP.

The present invention provides a method of preparing a furan derivative comprising the steps of (a) converting a monosaccharide to provide a keto-intermediate product; and (b) dehydrating the keto-intermediate product to provide a furan derivative; wherein the keto-intermediate product is pre-disposed to forming keto-furanose tautomers in solution. The method may further comprise a step of oxidizing the furan derivative to provide a furandicarboxylic acid or a furandicarboxylic acid derivative.

The disclosure discloses a production method for low-toxin, low-viscosity and enhanced-quality corn steep liquor protein powder with a special flavor, belonging to the field of biological technologies. By inoculating a corresponding proportion of 10.sup.6 CFU/mL Aspergillus niger spore suspension into corn steep liquor and cultivating it at a certain rotation speed and temperature, the viscosity of the corn steep liquor effectively reduced, and the aflatoxins contamination is significantly reduced. The degradation rate of AFB1, AFB2, AFG1, AFG2 reach 52.14%, 80.21%, 86.31%, 80.22%. After fermentation, the protein content and total amino acid content of the corn steep liquor are increased after drying, and it can be dried into corn steep liquor powder. The disclosure provides a technical reference for the safe and efficient utilization of the corn steep liquor, greatly reduces the transportation cost of the corn steep liquor, extends the product storage period, and improves the convenience in use.