The present disclosure provides a novel serine protease variant.

The present disclosure provides a Bifidobacterium lactis (B. lactis) strain XLTG11 and a use thereof. The strain belongs to Bifidobacterium lactis. The B. lactis strain XLTG11 was deposited in the China General Microbiological Culture Collection Center (CGMCC) on Oct. 25, 2019, with a taxonomic name of Bifidobacterium lactis XLTG11 and an accession number of CGMCC No. 18738. The B. lactis strain XLTG11 provided by the present disclosure can regulate an inflammatory cytokine, improve an intestinal barrier function, and modulate an intestinal flora by inhibiting the activation of a TLR4/MYD88/NF-κB signaling pathway, thereby alleviating dextran sulfate sodium (DSS)-induced colitis. In addition, the B. lactis strain XLTG11 has an immune-enhancing effect on a cyclophosphamide (CTX)-induced mouse immunosuppression model.

The disclosure discloses a Saccharopolyspora composition and its application in foods, and belongs to the technical field of food fermentation. The disclosure screens Saccharopolyspora hirsuta J2 and Saccharopolyspora jiangxiensis J3 that have an effect of reducing biogenic amine content from wheat koji, and the two strains are prepared into a Saccharopolyspora mixed preparation for use in a preparation process of a fermented alcoholic beverage, fermented food or fermented condiment, so that amino acid content and nutritional value of a fermented product can be improved while the biogenic amine content is reduced, thereby achieving effects of enhancing quality of the fermented food and improving safety of the fermented food, and therefore, the Saccharopolyspora composition has a broad application prospect.

The present invention relates to a method for preparing a plasmid containing DNA that encodes a Type I polyketide synthase (PKS), the method including a step of introducing a DNA construct containing tandem repeats of DNA that encodes a PKS into a Bacillus subtilis competent cell.

An oral biology model which comprises biofilm, oral epithelial tissue and a suspension of neutrophil-like cells in media is disclosed. The biofilm, which comprises oral bacteria, is produced by culturing oral bacteria on a solid substrate. The oral epithelial tissue may be gingival epithelial tissue to model the gingival crevice or buccal epithelial tissue to model the oral check. The suspension of neutrophil-like cells in media comprises neutrophil-like cells that are differentiated HL60 cells induced to a neutrophil-like phenotype by treatment with retinoic acid. Methods of using the oral biology model to test and compare compounds and formulations or to screen compounds and formulations for their effect on release of inflammatory signals, their effect on biofilm and oral bacteria and/or their effect on the cellular components are disclosed.

Methods of processing municipal solid wastes (MSW) are provided whereby concurrent enzymatic hydrolysis and microbial fermentation of wastes results in liquefaction of biodegradable components as well as accumulation of microbial metabolites. Liquefied biodegradable components are then separated from nondegradable solids to produce a bioliquid characterized in comprising a large percentage of dissolved solids of which a large fraction comprises some combination of acetate, ethanol, butyrate, lactate, formate or propionate. This bioliquid is, itself, a novel biomethane substrate composition, which permits very rapid conversion to biomethane. Methods of biomethane production are further provided using this bioliquid and using other biomethane substrate compositions produced by concurrent enzymatic hydrolysis and microbial fermentation of organic materials.

The invention provides a method of processing MSW comprising the steps ofproviding a stream of unsorted MSW to a microbial fermentation reactor in which the MSW is fermented with agitation at a non-water content of between 10 and 50% by weight and at a temperature of between 35 and 75 degrees for a period of between 1 and 72 hours under conditions sufficient to maintain a live lactic acid bacteria concentration of at least 10,000,000,000 CFU/L, andremoving a stream of fermented unsorted MSW from the reactor and subjecting it to a separation step whereby non-degradable solids are removed to provide a slurry of biodegradable components. Further, a slurry of bio-degradable components prepared according to said method is provided.

The present disclosure provides a Bifidobacterium lactis (B. lactis) strain XLTG11 and a use thereof. The strain belongs to Bifidobacterium lactis. The B. lactis strain XLTG11 was deposited in the China General Microbiological Culture Collection Center (CGMCC) on Oct. 25, 2019, with a taxonomic name of Bifidobacterium lactis XLTG11 and an accession number of CGMCC No. 18738. The B. lactis strain XLTG11 provided by the present disclosure can regulate an inflammatory cytokine, improve an intestinal barrier function, and modulate an intestinal flora by inhibiting the activation of a TLR4/MYD88/NF-?B signaling pathway, thereby alleviating dextran sulfate sodium (DSS)-induced colitis. In addition, the B. lactis strain XLTG11 has an immune-enhancing effect on a cyclophosphamide (CTX)-induced mouse immunosuppression model.

The invention provides a method of processing MSW comprising the steps ofproviding a stream of unsorted MSW to a microbial fermentation reactor in which the MSW is fermented with agitation at a non-water content of between 10 and 50% by weight and at a temperature of between 35 and 75 degrees C. for a period of between 1 and 72 hours under conditions sufficient to maintain a live lactic acid bacteria concentration of at least 10,000,000,000 CFU/L, andremoving a stream of fermented unsorted MSW from the reactor and subjecting it to a separation step whereby non-degradable solids are removed to provide a slurry of biodegradable components. Further, a slurry of bio-degradable components prepared according to said method is provided.

The disclosure discloses a Saccharopolyspora composition and its application in foods, and belongs to the technical field of food fermentation. The disclosure screens Saccharopolyspora hirsuta J2 and Saccharopolyspora jiangxiensis J3 that have an effect of reducing biogenic amine content from wheat koji, and the two strains are prepared into a Saccharopolyspora mixed preparation for use in a preparation process of a fermented alcoholic beverage, fermented food or fermented condiment, so that amino acid content and nutritional value of a fermented product can be improved while the biogenic amine content is reduced, thereby achieving effects of enhancing quality of the fermented food and improving safety of the fermented food, and therefore, the Saccharopolyspora composition has a broad application prospect.