Abstract: The present invention provides a transformant into which has been incorporated DNA for coding a foreign protein having lactate dehydrogenase activity and provided with pyruvic acid substrate affinity that equals or exceeds the pyruvic acid substrate affinity of the pyruvate decarboxylase inherent in the host organism. Said transformant can stably mass-produce lactic acid inside a host organism having the pyruvate decarboxylase gene.

Abstract: This invention provides a polynucleotide that encodes a protein having lactate dehydrogenase activity and such protein that can be used for producing D-lactic acid. This polynucleotide has the nucleotide sequence as shown in SEQ ID NO: 1 (a), and it hybridizes under stringent conditions with a probe comprising all or part of the nucleotide sequence as shown in SEQ ID NO: 1 or a complementary strand thereof and encodes a protein having D-lactate dehydrogenase activity (b).

Abstract: This invention provides a polynucleotide that encodes a protein having lactate dehydrogenase activity and such protein that can be used for producing D-lactic acid. This polynucleotide has the nucleotide sequence as shown in SEQ ID NO: 1 (a), and it hybridizes under stringent conditions with a probe comprising all or part of the nucleotide sequence as shown in SEQ ID NO: 1 or a complementary strand thereof and encodes a protein having D-lactate dehydrogenase activity (b).

Abstract: This invention provides a polynucleotide that encodes a protein having lactate dehydrogenase activity and such protein that can be used for producing D-lactic acid. This polynucleotide has the nucleotide sequence as shown in SEQ ID NO: 1 (a), and it hybridizes under stringent conditions with a probe comprising all or part of the nucleotide sequence as shown in SEQ ID NO: 1 or a complementary strand thereof and encodes a protein having D-lactate dehydrogenase activity (b).

Abstract: The present invention provides a transformant into which has been incorporated DNA for coding a foreign protein having lactate dehydrogenase activity and provided with pyruvic acid substrate affinity that equals or exceeds the pyruvic acid substrate affinity of the pyruvate decarboxylase inherent in the host organism. Said transformant can stably mass-produce lactic acid inside a host organism having the pyruvate decarboxylase gene.

Abstract: The present invention relates to a method of expressing a gene by inserting the genome into a host organism using genetic engineering techniques. The present invention further relates to a novel promoter, a recombinant vector containing the promoter and a target gene, a transformant containing the recombinant vector, and a method of producing a useful gene product or useful substance using the transformant.

Abstract: A basic antimicrobial protein is activated by a partner protein having an isoelectric point below pH 7 and a chaperon function, by expressing an antimicrobially inactive fusion protein between the basic antimicrobial protein and the partner protein, recovering the fusion protein and separating the two proteins from each other. In such manner, an advantageous mass expression system of the basic antimicrobial protein having an appropriate disulfide bond as an active type is realized at lost cost.

Abstract: A host-vector system suitable for production of human growth hormone (hGH) and a process for production of hGH using the same are provided. As an hGH expression plasmid, a recombinant DNA wherein a DNA coding for hGH is linked to the 3'-terminal of a DNA containing a promoter region derived from Bacillus brevis is provided, and as a host, especially a mutant Bacillus brevis substantially not exhibiting protease activity to hGH is provided. A microorganism obtained by transforming said host with said hGH expression plasmid efficiently produces hGH when it is cultured.

Abstract: A method for detecting or quantitating a mutagenic substance in a sample includes culturing a host microorganism transformed with a recombinant gene comprising an SOS gene and genes expressing luciferase activity and optionally genes expressing an enzyme which catalyzes the production of a substrate for luciferase, positioned downstream of the SOS gene, in a medium to which the sample is added; and measuring a luminescence generated by expression of the gene expressing luciferase activity. The method is sensitive, accurate and non-time consuming; and gene systems used for said method, i.e., a recombinant gene comprising an SOS gene expressed when a DNA is damaged and a gene expressing luciferase activity positioned downstream of the SOS gene, and a host microorganism transformed with said recombinant gene. Preferably the recombinant gene further comprises a gene expressing an enzyme which catalyses the production of a substrate for the luciferase in the down stream of the SOS gene.

Abstract: A highly thermostable polypeptide possessing protein disulfide isomerase (PDI) activity, a gene coding for the polypeptide and a process for producing the polyeptide are provided. The polypeptide possessing PDI activity is characterized by A) having a capability of catalyzing a disulfide exchange in proteins, B) recognizing mainly ribonuclease A as a substrate, C) having a suitable active temperature of 20.degree. to 70.degree. C., D) being stable at a pH value of 6 to 9, and E) having a molecular weight of about 60,000 to 62,000. Since it has a higher thermostability and exhibits a stable activity in a wider dithiothreitol concentration range as compared with the conventional PDI, it is possible to provide a novel enzyme active protein which can be advantageously used for a refolding reaction of certain proteins.

Abstract: A highly thermostable polypeptide possessing protein disulfide isomerase (PDI) activity, a gene coding for the polypeptide and a process for producing the polypeptide are provided. The polypeptide possessing PDI activity is characterized by A) having a capability of catalyzing a disulfide exchange in proteins, B) recognizing mainly ribonuclease A as a substrate, C) having a suitable active temperature of 20.degree. to 70.degree. C., D) being stable at a pH value of 6 to 9, and E) having a molecular weight of about 60,000 to 62,000. Since it has a higher thermostability and exhibits a stable activity in a wider dithiothreitol concentration range as compared with the conventional PDI, it is possible to provide a novel enzyme active protein which can be advantageously used for a refolding reaction of certain proteins.

Abstract: Method and apparatus for determination of the concentration of a component in a solution, such as ethyl alcohol in gasohol, acetic acid in hexane-acetic acid solution, or the like. Such determination is made with ease and accuracy based on a rate of pressure change caused in a closed container due to mass transfer occurring between two liquids through porous material.

Abstract: A gas separating member of the present invention comprises a porous substrate in the form of a film, wall or hollow fiber and a polymer film formed on a surface of the substrate by plasma polymerization. The gas separation factor (O.sub.2 /N.sub.2) ranges from 2.3 to 3.9 with the corresponding gas permeability ranging from 12 to 0.16 liter/min. m.sup.2 atm. pres.-air.A modified gas separating member of the present invention, which comprises a porous substrate in the aforementioned form and two polymer films formed on a surface of the substrate by plasma polymerization, has the gas separation factor (He/H.sub.2) ranging from 14 to 45.