The present disclosure provides recombinant microorganisms and methods for the production of 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA from a carbon source. The method provides for engineered microorganisms that express endogenous and/or exogenous nucleic acid molecules that catalyze the conversion of a carbon source into 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA. The disclosure further provides methods of producing polymers derived from 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA.

A method for expressing, as a soluble protein or an active-form mutant enzyme, an enzyme that cannot be expressed as a soluble protein or an active-form enzyme in a heterologous expression system or that is obtained in a minute amount even when an active-form enzyme is expressed, the method including a technique for selecting an effective mutation site and a mutated amino acid. A new active-form mutant enzyme is also disclosed. The method involves: specifying an insoluble protein or an inactive-form enzyme; specifying a hydrophilic amino acid in a hydrophobic domain and/or a hydrophobic amino acid in a hydrophilic domain of an -helix structure portion of the insoluble protein or the inactive-form enzyme and preparing a gene that codes for an amino acid sequence in which a substitution is made to the hydrophilic amino acid in the hydrophobic domain and/or the hydrophobic amino acid in the hydrophilic domain.

A Myrmecridium flexuosum NUK-21, a novel lactose oxidase isolated from the Myrmecridium flexuosum NUK-21 and a method for conversion of lactose into lactobionic acid (LBA) by the novel lactose oxidase are disclosed herein. The Myrmecridium flexuosum NUK-21 produces high yields of the novel lactose oxidase and the novel lactose oxidase has higher reactivity and specificity of converting lactose into lactobionic acid.

The present invention provides for a method for producing hydrogen peroxide comprising: (a) contacting a methanol with a methanol oxidase bound with a flavin adenine dinucleotide (FAD) cofactor, such that the methanol is oxidized into a formaldehyde and the FAD cofactor is reduced into FADH.sub.2; (b) contacting the formaldehyde with the methanol oxidase or a formate oxidase bound with a FAD cofactor, such that the formaldehyde is oxidized into a formate and the FAD is reduced into FADH.sub.2; and (c) contacting oxygen with one or more of the FADH.sub.2 to produce hydrogen peroxide and oxidize FADH.sub.2 into FAD. The present invention also provides for a fusion protein comprising any two or all of methanol oxidase, formate oxidase, and formaldehyde dismutase.

The present invention provides a protein having pentosidine oxidase activity, a method for measuring pentosidine comprising: contacting the protein with a specimen; and detecting a change caused by the contact, and the like.

The present disclosure provides recombinant microorganisms and methods for the production of 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA from a carbon source. The method provides for engineered microorganisms that express endogenous and/or exogenous nucleic acid molecules that catalyze the conversion of a carbon source into 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA. The disclosure further provides methods of producing polymers derived from 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA.

A Myrmecridium flexuosum NUK-21, a novel lactose oxidase isolated from the Myrmecridium flexuosum NUK-21 and a method for conversion of lactose into lactobionic acid (LBA) by the novel lactose oxidase are disclosed herein. The Myrmecridium flexuosum NUK-21 produces high yields of the novel lactose oxidase and the novel lactose oxidase has higher reactivity and specificity of converting lactose into lactobionic acid.

A method for expressing, as a soluble protein or an active-form mutant enzyme, an enzyme that cannot be expressed as a soluble protein or an active-form enzyme in a heterologous expression system or that is obtained in a minute amount even when an active-form enzyme is expressed, the method including a technique for selecting an effective mutation site and a mutated amino acid. A new active-form mutant enzyme is also disclosed. The method involves: specifying an insoluble protein or an inactive-form enzyme; specifying a hydrophilic amino acid in a hydrophobic domain and/or a hydrophobic amino acid in a hydrophilic domain of an -helix structure portion of the insoluble protein or the inactive-form enzyme and preparing a gene that codes for an amino acid sequence in which a substitution is made to the hydrophilic amino acid in the hydrophobic domain and/or the hydrophobic amino acid in the hydrophilic domain.

The present disclosure provides recombinant microorganisms and methods for the production of 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA from a carbon source. The method provides for engineered microorganisms that express endogenous and/or exogenous nucleic acid molecules that catalyze the conversion of a carbon source into 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA. The disclosure further provides methods of producing polymers derived from 4-HMF, 2,4-furandimethanol, furan-2,4-dicarbaldehyde, 4-(hydroxymethyl)furoic acid, 2-formylfuran-4-carboxylate, 4-formylfuran-2-carboxylate, and/or 2,4-FDCA.

Disclosed herein is a printable liquid lactate sensor composition including silk fibroin in an amount by weight of between 0.1% and 30%, a lactate oxidase that is activated by lactate to produce hydrogen peroxide, a peroxidase that is activated by the hydrogen peroxide, and a chromogenic substrate that changes color upon activation of the peroxidase. Wearable sensors including the printable liquid lactate sensor composition are disclosed herein.