Abstract: The invention provides a promoter capable of expressing an introduced gene in plant seeds, a vector comprising said promoter, a method for producing transgenic plants through transformation of plants with said vector, and a transgenic plant as transformed with said vector.After a suitable foreign gene and a terminator are linked to the promoter, the resulting vector may be introduced into seeds of barley or other plants, thereby intentionally modifying the seeds and making the resulting seeds produce foreign substances therein.

Abstract: A recombinant .beta.-amylase which is superior to the original recombinant .beta.-amylase in thermostability has been obtained by a site-directed mutagenesis with the recombinant .beta.-amylase gene coding 531 amino acid residues. Substitutions were MET.sub.181 of said enzyme with Leu, Ser.sub.291 with Ala, Ile.sub.293 with Val, Ser.sub.346 with Pro, Ser.sub.347 with Pro, Gln.sub.348, with Asp and Ala.sub.372 with Ser.

Abstract: The present invention provides a barley .beta.-amylase structural gene consisting of the nucleotide sequence shown in SEQ. ID. No. 1 in attached sequence listing, a barley .beta.-amylase structural gene consisting of the nucleotide sequence shown in SEQ. ID. No. 2 in attached sequence listing, and a plasmid containing the nucleotide sequence shown in SEQ. ID. NO. 1 or 2 in attached sequence listing. The present invention can be utilized in breeding of barley and other plants and industrial production of .beta.-amylase and can contribute in the technical fields of plant breeding, production of brewed products such as beer, production of distilled liquors, food production and enzyme industry.

Abstract: A recombinant .beta.-amylase which is superior to the original recombinant .beta.-amylase in thermostability has been obtained by a site-directed mutagenesis with the recombinant .beta.-amylase gene coding 531 amino acid residues. Substitutions were MET.sub.181 of said enzyme with Leu, Ser.sub.291 with Ala, Ile.sub.293 with Val, Ser.sub.346 with Pro, Ser.sub.347 with Pro, Gln.sub.348 with Asp and Ala.sub.372 with Ser.

Abstract: A process for the preparation of maltopentaose is disclosed, comprising cultivating a maltopentaose-producing microorganism belonging to a genus Bacillus in a medium and isolating the thus-accumulated maltopentaose from the culture broth. A typical example of the maltopentaose-producing microorganism is Bacillus cereus NY-14. This process permits the preparation of maltopentoase without the use of amylase as in conventional methods. Maltopentaose is useful, for example, as a substrate for the determination of serum amylase.