Dr. Ishii, Director of Chemical Analysis Research Center, won the Award of Pesticide Science Society of Japan in 2003. With the increase in the kinds of pesticides being used in agricultural production, however, it has become impossible to monitor pesticide residue levels in food effectively and meaningfully by means of the methods used for individual pesticides. The only reasonable approach to monitoring the pesticide residues is to simplify the analyses by developing methods that measure more than one pesticide at a time. For such a purpose, Dr. Ishii has improved and developed the existing pesticide residue analysis methods as follows:

(1) Application of high-performance liquid chromatography (HPLC) to pesticide residue analysis.

HPLC was used for the improvement in sensitivity and accuracy of the residue analyses of strong polar pesticides and ionic pesticides. The method for measuring the amount of the combination of methyl benzimidazol-2-ylcarbamate (MBC) that thiophanate methyl (TM) in crops are chemically converted and MBC in crops is adopted as an official method of TM. He found MBC and two oxygen analogues of TM in the photo-degradation products of TM. He developed analysis method that was able to measure TM and the main degradation products simultaneously.

Average recoveries for TM and its degradation products from fortified samples were 70~104% at 0.5 ppm levels. The minimum detectable amount was ca 5 ng for TM and its degradation products.

He also tried to develop an analysis method for ionic herbicides such as paraquat and diquat that used HPLC equipped with an ultraviolet detector. The minimum detectable amount of paraquat was 0.1 ng at 254 nm. Diquat was also detected in subnanogram quantities. The detection limit of paraquat was 0.0005 ppm in 100-g crop samples and 0.002 ppm in 25-g soil samples. Recoveries were 80% to 104% from crop samples fortified at 0.1 to 0.5 ppm and 70% to 100% from soil samples fortified at 0.4 to 2 ppm. The sensitivity of the new analysis method is at least ten times higher than that of the classical colorimetric method.

(2) Rapid cleanup procedure with a charcoal-Florisil minicolumn for multiresidue analysis.

A simple and efficient cleanup procedure for gas chromatographic determination of pesticide residues was developed by using a charcoal-Florisil minicolumn. The pesticide residues were extracted with methanol, partitioned into toluene, cleaned up with the minicolumn, and determined by gas chromatography. Recovery data were obtained from 15 crops fortified with 25 pesticides at their tolerance levels. Recoveries of 23 pesticides were higher than 90%. The detection limits were 0.01 to 0.02 ppm for organophosphates, 0.05 ppm for carbamates and synthetic pyrethroids, and 0.005 ppm for organochlorines.

(3) Application of preparative liquid chromatography to a residue analysis cleanup procedure.

Preparative chromatography, especially gel permeation chromatography (GPC), was evaluated as a possible cleanup technique for determining pesticide residues. The residues were cleaned up with a GPC system in which Bio-Beads SX-3 was used as the gel. Pesticides were determined by GC-flame photometric detector, GC-thermionic alkali flame ionization detector, and Hall electrocoductivity detector. Recovery data are presented for more than 60 pesticides (organophosphates, carbamates, synthetic pyrethroids, organochlorines) in 19 crops. Average recoveries ranged from 70% to 120% at 0.1- to 10 ppm fortification levels. The detection limits ranged from 0.005 to 0.05 ppm.

(4) Immunochemical assay of pesticide residue

Highly reactive monoclonal antibodies for bensulfuron-methyl, pyrazosulfuron-ethyl, thiobencarb, and mefenacet were prepared. With the antibodies, a simultaneous competitive enzyme-linked immunosorbent assay (ELISA) was carried out. The assay provided the tool for the determination of residues of the four herbicides in water without any pre-treatment of the water sample. Determination concentrations ranged from 0.2 to 1.5 ng/ml for bensulfuron-methyl, 0.2 to 4.5 ng/ml for pyrazosulfuron-ethyl, 0.2 to 3.4 ng/ml for thiobencarb, and 0.2 to 4 ng/ml for mefenacet.

Of many factors limiting crop productivity in acid soils which comprise approximately 40 % of the arable land in the world, aluminum (Al) toxicity and phosphorus (P) deficiency are generally considered as the major problems. The elucidation of the mechanisms involved in tolerances to excess Al and P deficiency in plants is needed to help in the breeding of plants that increase yields in acid soils.

Dr. Satoru Ishikawa revealed that the root plasma membrane in Al-tolerant plants can exclude Al, indicating the prevention of Al entry into the cytoplasm. He also found that the exclusion of Al is closely associated with the binding of Al ions to the membrane lipids, which is a major constituent of the plasma membrane. This finding would be useful for the development of Al-tolerant plants through breeding.

Pigeonpea, which is an important leguminous crop in semi-arid tropics, is known to utilize unavailable P in soils by exuding piscidic acid from its roots. However, he found that the exudation of piscidic acid is an unsatisfactory strategy for explaining genotypic variation in low P availability of pigeonpea and suggested the existence of more powerful strategy related to P acquisition.

The Japanese Society of Soil Science and Plant Nutrition presented its annual award for the encouragement of young scientists to Dr. S. Ishikawa, because his research remarkably contributed to elucidate the mechanisms for tolerances to Al and P deficiency in plants.

The Phytopathological Society of Japan presented its annual award for the encouragement of young scientists to Dr. Shigenobu Yoshida, because his research remarkably contributed to the advance and development of plant pathology regarding mulberry anthracnose.

Mulberry anthracnose is a disease commonly observed in mulberry fields in Japan and has increased.  However, physiological and ecological studies leading to the establishment of effectual control strategies against the disease have never been reported.  Dr. Shigenobu Yoshida revealed that the causal fungi of the disease were verified as Colletotrichum dematium, C. acutatum and Glomerella cingulata, in addition to C. morina that has been reported as the causal fungus.  He found that C. dematium overwinters mainly in infected mulberry leaves on the ground, then first infects the leaves adjacent to the ground in the rainy season.  The fungal infection then develops in the middle, and then upper foliages of mulberry trees with time, regardless of leaf age, indicating that removal of fallen leaves from the mulberry field in autumn contributes to disease control.

Moreover, he clarified that extracts obtained from C.  dematium grown on mulberry leaves caused brown necrotic lesions, a typical symptom of this disease, and that the phytotoxins were host-nonspecific but played a role in the fungal pathogenesis in mulberry leaves through the development of the lesions.  He also found a potential antagonist; Bacillus amyloliquefaciens strain RC-2, against C.  dematium obtained from healthy mulberry leaves.  He isolated the 7 kinds of antifungal compounds, which were determined to be iturin derivatives by NMR and FAB-MS analyses.

The Takeda Techno-Entrepreneurship Award is presented to research proposals that show the greatest promise of contribution to human well-being, through the creation and application of new engineering knowledge.  The practical application or commercialization of this engineering knowledge (i.e., techno-entrepreneurship), which will generate substantial value for the public in the near term, is the mission of the Takeda Foundation.  Three application fields are covered by the awards: Information and Electronics, Life Sciences, and World Environment.

Dr. Kazuhiro Takagi and other research group members (Nagoya University) were awarded the Takeda Techno-Entrepreneurship Award for the above research in Environmental Biotechnology.  Our research plan consisted of three steps as follows:

1. Characterization of the PCB-degrading anaerobic consortia obtained from surface soils and subsoils

2. Development of a carrier for the degrading anaerobic consortia which maintained high activity

3. Carrier-mediated introduction of the degrading consortia into contaminated subsoil environment

Dr. Takagi 's research contributed to Step 2 and Step 3.  Especially, his developed carrier enriched with degrading bacteria consortia to remedy contaminated soil is available under aerobic conditions in the field.  For these reasons, he was awarded the Takeda Techno- Entrepreneurship Award