Akinori Amemura

Chiral discrimination of permethylated gluco-oligosaccharide toward amino acid ester salts

The chiral discrimination ability of permethylated glucopyrano-oligosaccharides toward amino acid 2-propyl ester hydrochlorides was evaluated using FAB mass spectrometry. In the given permethylated homo-oligosaccharides, permethylated β-cello-oligosaccharide series (II) showed remarkably higher S-selectivity toward tryptophan ester salts (Trp-O-iPr+) independent of the numbers (n) of the glucopyranose unit (n=2–5). The hexamer and heptamer of the permethylated β-malto-oligosaccharide series (I) showed the very similar enantioselectivity to permethylated α- and β-cyclodextrin.

Analysis of the rpoD gene encoding the principal sigma factor of Pseudomonas putida

The gene (rpoD) encoding the principal sigma factor of Pseudomonas putida (Pp) was cloned and sequenced. The amino-acid sequence deduced from the nucleotide sequence of rpoD contained sequences with significant similarity to the conserved region of the principal sigma factors. In vivo transcriptional analyses revealed that the Pp rpoD is transcribed as a monocistronic mRNA of 2.1 kb and that the transcription of rpoD is under control of the heat-shock (HS) response. The transcription start point (tsp) of the gene was determined and found to be different depending on either normal growth (at 30 degrees C) or HS (at 42 degrees C) conditions. The possible promoter sequences for the principal (sigma 70) and the HS RNA polymerase of Pseudomonas were located in the upstream region of the tsp.

Isolation of a microalga, Synechocystis sp. SY-4, potentially useful as a rotifer feed

An algal strain, SY-4, that grows between 25°C and 35°C was isolated from coastal seawater by enrichment culture, and identified as a blue-green alga (cyanobacterium) of the Synechocystis species. This microorganism was found to be a potentially useful feed for rotifer culture.

Identification and DNA sequencing of a new plasmid (pPST1) in Pseudomonas stutzeri MO-19

A cryptic plasmid, pPST1, was isolated from Pseudomonas stutzeri MO-19 and its complete nucleotide sequence was determined. This plasmid consisted of 1446 bp and could encode a putative polypeptide of 152 amino acid residues (ORF1) in an open reading frame. The putative protein contained a sequence homologous to the sequences found in DNA-binding sites.