Takeshi Sakane

Purification and gene cloning of a chitosanase from Bacillus ehimensis EAG1

Bacillus ehimensis EAG1 (IFO15659) produced and secreted chitosanase in the presence of exogenous chitosan. The chitosanase was purified from the culture filtrate of the bacterium to apparent homogeneity in SDS-polyacrylamide gel electrophoresis. The purified enzyme had a molecular weight of approximately 31,000. A 1.9-kbp DNA fragment containing the chitosanase gene was cloned and the complete nucleotide sequence was determined. The sequence was found to contain a single open reading frame encoding a protein of 302 amino acids. The deduced amino acid sequence showed significant homology with the chitosanase from Bacillus circulans MH-K1.

Kinetic Resolution of an Indan Derivative Using Bacillus sp.SUI-12 : Synthesis of a Key Intermediate of the Melatonin Receptor Agonist TAK-375

The chiral indan derivative (S)-2 (2-[(8S)-1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan-8-yl]ethyl-amine) was synthesized by enzyme-catalyzed asymmetric hydrolysis of the racemic acetamide 1 (N-[2-(1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan-8-yl)ethyl]acetamide). The reaction was carried out using Bacillus sp. SUI-12 screened for the ability to hydrolyze 1 to give (S)-2 with high enantioselectivity. In a scaled-up experiment, a low reaction rate was observed. However, by changing the culture medium and the reaction conditions, it became possible to run the reaction to 40% conversion on a 10-g or more scale, obtaining (S)-2 at >;99% enantiomeric excess (ee). The (S)-2 obtained was available for the synthesis of the melatonin receptor agonist TAK-375 (N-[2-[(8S)-1,6,7,8-tetrahydro-2H-indeno[5,4-b]furan-8-yl]ethyl]propanamide).

Isolation and Taxonomie Characterization of Acid Urease-producing Bacteria

About 16,000 isolates from animal feces and intestines were assayed for the production of acid urease, and the 700 strains selected as producers were examined as to their taxonomic properties. Of these 700 strains, 370 belonged to the genus Streptococcus, 312 to the genus Lactobacillus, 9 to the genus Escherichia, 6 to the genus Staphylococcus, 2 to the genus Morganella and 1 to the genus Bifidobacterium. The majority of the streptococci were identified as Streptococcus mitior, the remainder being Streptococcus salivarius, Streptococcus faecalis, Streptococcus faecium, Streptococcus avium and Streptococcus gallinarum. The majority of the lactobacilli were considered to be Lactobacillus reuteri or Lactobacillus fermentum and Lactobacillus animalis or Lactobacillus salivarius, the remainder being Lactobacillus ruminis, Lactobacillus viridescens, Lactobacillus vac- cinostercus and strains considered to be Lactobacillus acidophilus, Lactobacillus amylovorus, Lactobacillus crispatus or Lactobacillus gasseri.