The present invention relates to a method for preparing hot pepper paste (gochujang in Korean) by using a novel strain, and hot pepper paste prepared therefrom. More specifically, the hot pepper paste having a consistent quality and improved flavor and taste can be prepared by isolating and selecting Aspergillus oryzae having remarkable carbohydrate and protein degradation enzymatic activities from traditional meju (fermented soybeans) by using wheat flour or polished wheat as a substrate, and using the isolated and selected product for preparing the hot pepper paste.

Recombinant Aspergillus genetically modified to increase expression of g8846, renamed herein as aconitic acid exporter (aexA), are provided, which in some examples are also genetically inactivated for an endogenous cis-aconitic acid decarboxylase (cadA) gene. Such recombinant Aspergillus produce more aconitic acid as compared to native Aspergillus. Also provided are methods of using such recombinant Aspergillus to increase production of aconitic acid and other organic acids, such as citric acid, itaconic acid, and 3-hydroxypropionic acid (3-HP).

The present invention discloses an Aspergillus oryzae JAAS-32 and use thereof in preparation of a larval Hermetia illucens paste protein peptide. The Aspergillus oryzae JAAS-32 was deposited in Guangdong Microbial Culture Collection Center (GDMCC) on Aug. 10, 2023 with an accession number of GDMCC No: 63725, classified and named Aspergillus oryzae. A larval Hermetia illucens paste is subjected to enzymatic fermentation by the Aspergillus oryzae JAAS-32 provided by the present invention for 20-40 hours. The content of the protein peptide (<10 kDa) is 1.53 times that of an untreated group; the content of free amino acids is 1.41 times that of the untreated group; the total antioxidant activity is 1.35 times that of the untreated group. Diameters of inhibition zones against Staphylococcus aureus, Escherichia coli, and Vibrio alginolyticus are 1.62, 1.17, and 1.45 times those of the untreated group, respectively. The strain is cultured readily, fast in growth, and well-adapted. A low-cost, easy-to-operate, and efficient method for enhancing antibacterial performance of the larval Hermetia illucens paste can be established on the basis of the strain.

The present invention discloses an Aspergillus oryzae JAAS-32 and use thereof in preparation of a larval Hermetia illucens paste protein peptide. The Aspergillus oryzae JAAS-32 was deposited in Guangdong Microbial Culture Collection Center (GDMCC) on Aug. 10, 2023 with an accession number of GDMCC No: 63725, classified and named Aspergillus oryzae. A larval Hermetia illucens paste is subjected to enzymatic fermentation by the Aspergillus oryzae JAAS-32 provided by the present invention for 20-40 hours. The content of the protein peptide (<10 kDa) is 1.53 times that of an untreated group; the content of free amino acids is 1.41 times that of the untreated group; the total antioxidant activity is 1.35 times that of the untreated group. Diameters of inhibition zones against Staphylococcus aureus, Escherichia coli, and Vibrio alginolyticus are 1.62, 1.17, and 1.45 times those of the untreated group, respectively. The strain is cultured readily, fast in growth, and well-adapted. A low-cost, easy-to-operate, and efficient method for enhancing antibacterial performance of the larval Hermetia illucens paste can be established on the basis of the strain.

The purpose of the present invention is to provide a method for producing selenoneine that allows production of selenoneine at higher yields, even if an inorganic selenium compound is used as a selenium compound. This purpose can be achieved by a method for producing selenoneine, comprising the step of applying histidine and a selenium compound to a transformant to obtain selenoneine, wherein the transformant has at least one gene selected from the group consisting of a SatA gene, a CysB gene and a MetR gene, and an EgtA gene inserted therein and can overexpress the inserted genes.

A method for producing a secreted -galactosidase, characterized by integrating a non-secreted -galactosidase gene derived from a basidiomycetous yeast into Aspergillus oryzae to produce a secreted -galactosidase, and a method for producing a galactooligosaccharide using a -galactosidase produced by the method facilitate the production of a galactooligosaccharide.

An organic solid-state fermentation enzyme formulation and an organic plant protease hydrolysate, and preparation methods therefor. The organic solid-state fermentation enzyme formulation is prepared by solid-state fermentation of protease-producing microorganisms, wherein the organic solid-state fermentation enzyme formulation comprises neutral protease, acidic protease, alkaline protease, glucoamylase, and cellulase. By means of using the protease-producing microorganisms to perform solid-state fermentation on organic plant raw materials, the organic solid-state fermentation enzyme formulation rich in the acidic protease, the neutral protease, the alkaline protease, the cellulase, and the glucoamylase is obtained, and then a small amount of additional enzyme is added in the organic solid-state fermentation enzyme formulation, thereby improving the plant proteolysis efficiency by means of an enzyme system synergistic complementary effect.