092-642-3059

092-642-3059

Doctor of Philosophy (Agricultural science)

Applied Microbiology

(1) Research activity:

Utilization of Microbial Genetic Resources.

The goal of the research is to ensure that the genetic diversity of agriculturally important microorganisms is maintained to enhance and increase agricultural efficiency and profitability. The Research will collect, authenticate and characterize potentially useful microbial germplasm stock; preserve microbial genetic diversity; and facilitate distribution and utilization of microbial germplasm for research and industry.

Main targets of the Research are Streptomyces species, Lactic acid bacteria and hyperthermophilic bacteria.

(2) Educational activity:

Professional education and moral tutor for foregin students.

University and graduate school education on the Depertment of Genetic Resources Technology in the Graduate School of Bioresource and Bioenvironmental Sciences and School of Agriculture.

(3) Social activity:

Part-time lecturer of Towa University (Faculty of Engineering), Kyushu University (Faculty of Low),
Fukuoka Agricultural Science School (Department of Food Science) and Daiichi University (College of Pharmaceutical Sciences).

Research Interests

• Isolation and identification of virus infected to hyperthermopiles
  keyword : Extreamphiles, Hyperthermophiles, virus, phage
  2007.04.
• Study of biosilicification with Thermus species
  keyword : Thermus, biosilicification, silica-induced protein, silica
  1995.04.
• Structural and functional analysis of extrachromosomal elements in bacteria
  keyword : plasmis, bacteriophage, DNA translocation, site-specific recombination, gene targeting, evolution, conjugation
  1990.04.
• Investigation of environmentally-sound agricultural and livestock system using lactic acid bacteria
  keyword : silage, Lactic acid bacteria, bacteriocin, probiotics, identification
  1994.01.
• Spatial and temporal analysis of gene regulation for morphological and metabolic differentiation in Streptomyces
  keyword : Streptomyces, morphological and metabolic differentiation, gene regulation
  1990.04.

Current and Past Project

• Biochemical investigation of thermophilic microorganisms is main scope of JSPS project.
  Especially, my scope is isolation and characterization of a high bacteriocin producing thermophilic lactic acids bacteria from Thailand.
  
  Enterococcus sp. K-4, with a bacteriocin-like activity against E. faecium, was isolated from grass silage in Thailand. Morphological, physiological, and phylogenetic studies clearly identified strain K-4 as a strain of E. faecalis. Strain K-4 produced a maximal amount of bacteriocin at 43-45C. We purified, for the first time, the bacteriocin produced at high temperature by E. faecalis to homogeneity, using adsorption on cells of the producer strain and reversed-phase liquid chromatography. The bacteriocin, designated enterocin SE-K4, is a peptide of about 5 kDa as measured by SDS-PAGE, and Mass spectrometry analysis found the molecular mass of 5356.2, which is in good agreement. The amino acid sequencing of the N-terminal end of enterocin SE-K4 showed apparent sequence similarity to class IIa bacteriocins. Enterocin SE-K4 was active against E. faecium, E. faecalis, B. subtilis, Clostridium beijerinckii, and Listeria monocytogenes. Enterocin SE-K4 is very heat stable.
  Strain K-4 carries two plasmids, pEK4S (approximately 60 kb) and pEK4L (approximately 75 kb). Plasmid-curing experiments showed that pEK4S was involved in the production of and immunity to enterocin SE-K4 in strain K-4. A derivative strain, M6, with pEK4S produced a higher amount of enterocin SE-K4 than the parental strain K-4, although its growth rate was lower than that of parental strain K-4. Phenotypic changes in strain M6 are attributed to an increase in plasmid copy number.
  
  References:
  Eguchi et al., Biosci. Biotechnol. Biochem., 64 (2), 247-253 (2001)
  Doi et al., J. Biosci. Bioeng., 93 (4), 434-436 (2002)

Academic Activities

Educational Activities

Professional and Outreach Activities