Abstract: [Problem] The present invention has as an object to provide an antiviral agent effective as a remedy for COVID-1 9 and other viral infections. [Resolution Means] Provided is an antiviral agent and the like, made of: the compound represented by general formula (1) or (2) below [R1 being —(CH2)n1—Z1—R11 2 r —CH—(—Z1—R11,)(n1 being 0 or 1; Z1 being a single bond, —O—, —NH—, —S—, —SO—, —SO2—,SO—CO—, —CO—O—, or —CH?N—O—; R11 being a hydrogen atom, an alkyl group having 1 to 6 carbons, —NR12 R13, —N3,—NO2,—CN, —CH2—CO—O—R14, or a five- or six-membered heterocyclic group including a nitrogen atom; R12 and R13 each independently being a hydrogen atom or an alkyl group having 1 to 6 carbons; and R14 being a hydrogen atom or an alkyl group having 1 to 6 carbons], a derivative thereof, a salt of these compounds, or a solvate thereof.

Abstract: The present invention provides at least one protein selected from the group consisting of the following proteins (a) to (d): (a) a protein which is composed of an amino acid sequence set forth in SEQ ID NO: 1; (b) a protein which is, in the amino acid sequence set forth in SEQ ID NO: 1, composed of an amino acid sequence in which one or more amino acids other than tyrosine at position 40 are substituted, deleted, inserted, and/or added and has a fermented milk viscosity improving effect; (c) a protein which is composed of an amino acid sequence having 80% or more identity with the amino acid sequence set forth in SEQ ID NO: 1, has tyrosine as an amino acid corresponding to position 40 of the amino acid sequence set forth in SEQ ID NO: 1, and has a fermented milk viscosity improving effect; and (d) a protein which is composed of an amino acid sequence encoded by a DNA that hybridizes under stringent conditions with a complementary strand of a DNA composed of the nucleotide sequence set forth in SEQ ID NO: 2

Abstract: A gene to be integrated is bound to pAM.beta.1 plasmid to construct an integration plasmid, which is conjugally transferred into chromosomal DNA of a strain of Lactobacillus delbrueckii species. Integration of only the objective gene occurs through homologous recombination events (double crossing-over). According to this method, an arbitrary gene can be integrated into chromosomal DNA of a strain of Lactobacillus delbrueckii species and the DNA sequence derived from the vector, pAM.beta.1, can be completely removed. Therefore, the obtained gene integrant is widely applicable to the production of foods, medicines, feeds and the like.

Abstract: Disclosed is the plasmid pBUL1 having a restriction endonuclease cleavage map as shown in FIG. 1 and having a length of about 7.9 kbp and its derivatives. The plasmid was isolated from Lactobacillus delbrueckii subsp. bulgaricus M-878. The plasmid is useful as a vector for breeding various microorganisms such as lactic acid bacteria, and the derivatives thereof are useful also as a shuttle vector.

Abstract: Disclosed are the plasmid pBUL1 having a restriction endonuclease cleavage map as shown in FIG. 1 and having a length of about 7.9 kbp and its derivatives.The plasmid was isolated from Lactobacillus delbrueckii subsp. bulgaricus M-878.The plasmid is useful as a vector for breeding various microorganisms such as lactic acid bacteria, and the derivatives thereof are useful also as a shuttle vector (lactic acid bacteria--Escherichia coli).