Tokyo Date, names of president and members at the foundation of Japanese Society for Research of Freezing and Drying are mentioned. The development of the society, including brief outstanding reports, special researches by national money supply, reports on international congress in Tokyo and future expects on the society are added.

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Remarkable differences between rigor mortis and thaw rigor were examined in the muscle of carp. Glycolysis seems to be one factor which influences the amount of ATP. In the muscle of carp stored at 18℃ after instant death, the extent of rigor mortis was small, and the amounts of glycogen and ATP gradually decreased, while that of lactate increased slowly. On the other hand, the muscle of carp frozen rapidly after instant death and subsequently thawed and stored at 18℃ showed strong thaw rigor. Glycogen and ATP amounts decreased remarkably by the end of thaw rigor, whereas that of lactate increased markedly in thaw rigor. In the case of thaw rigor, it can be concluded that the contraction energy is mainly due to the large amount of ATP supplied through the rapid glycoysis. Influences of storage temperatures on the prolongation of pre-rigor period of sea bream were examined. The amount of ATP in the muscle of sea bream decreased more rapidly and rigor mortis proceeded faster at 0℃ than at 10℃. In the muscle stored at 10℃ the onset of rigor mortis occurred seven hours later than at 0℃. Wild and cultured of sea bream were stored at 0℃ and 10℃, and compared to each other with respect to the progress of rigor mortis. Rigor mortis began to occur earliest in the cultured specimen stored at 0℃, followed successively by the wild one at 0℃, the cultured one at 10℃, and the wild one at 10℃, demonstrating that the pre-rigor period of sea bream can be most effectively attained in the last case. The mechanism of thaw rigor was investigated in carp muscle in relation to myofibrillar ATPase and sarcoplasmic reticulum (SR) Ca^<2+> uptake activities as well as the change in muscle ultrastructures. No significant difference between carp immediately after death and that in thaw rigor was observed in myofibrillar ATPase. Ca^<2+> uptake activity of SR from the sample immediately after death was high, but it was nearly zero during thawing. Electron microscopic observation revealed that SR membranes were broken by freezing and thawing. The resultant Ca^<2+> release from SR probably caused the increase of ATP consumption and the acceleration of thaw rigor by activating myofibrillar Mg^<2+>-ATPase.

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An enzymatically modified gelatin with covalently attached leucine dodecyl ester (EMG-12) is highly surface-active with its hydrophilic-hydrophobic structure and acts to stabilize a supercooling state of water by antinucleation. EMG-12 also exerts cryoprotective effects on hypothermic preservation of biological systems such as grape cells and mouse embryos. On the other hand, antifreeze glycoproteins (AFGP) in the blood of winter polar fish protects the fish from freezing by ice crystal growth inhibition. Discussions are made on their structure-function relationships and utilization.

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In the Orient, there are many kinds of indigenous fermented foods such as Soy Sauce, Miso (fermented soy paste) , Natto (fermented whole soybeans) , Sufu (fermented soybean protein curd), Tempeh (fermented whole soybeans), Rice Vinegar, Katsuobushi (dried bonito) and alcoholic beverages. On the other hand, in the West, there are fermented foods such as Bread, Cheese, Yoghurt and many kinds of alcoholic beverages. Fermented food is related to water during the fermentation process, for example, material treatment (cooking, roasting, soaking etc.) , growth of microorganisms and maturing period. In this report, we introduced the relationship between the state of water and fermented food during the production process. Also, the effect of water activity (a_w) on the growth of microorganisms is discussed.

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Temperate species of the Drosophila melanogaster species group enter reproductive diapause for overwintering in response to short daylength. During the prediapause period, they accumulate triacylglycerols (TAGs) as energy resources for winter. Under laboratory conditions, the capacity for storing TAGs differs in different species, and appears to be closely correlated with diapause and cold-hardiness; cool-temperate species, such as those of the auraria species complex which enter a deep diapause and are highly cold-hardy accumulate a larger amount of TAGs than warm-temperate species, such as D. rufa and D. lutescens which enter a weak diapause and are less cold-hardy. On the other hand, a subtropical species, D. takahashii, which has no diapause in nature and is not cold-hardy, is unable to store as much TAGs as the temperate species. These species were tested winter survival and TAGs content under outdoor conditions in Sapporo (a cool-temperate region) , northern Japan. In the strains of cool-temperate species from northern Japan, individuals which eclosed in mid autumn accumulated TAGs up to 163 μg/ mg body weight and 50 to 70% of them survived until spring, while those which eclosed later in autumn accumulated less TAGs and had a lower ability to overwinter. The TAG content was lower in the warm-temperate species and the subtropical strain of D. triauraria, and dropped to very low levels by mid winter, and these species and strain were unable to survive until spring. These observations suggest that TAG level plays an important role in overwintering of the Drosophila species. In addition, differential scanning calorimetry analysis revealed that the transition temperatures of TAGs were lower in diapausing adults than in reproducing ones, and also lower in species or strains adapted to cooler climates than those adapted to warmer climates. These phenomena were correlated to the fatty acid compositions of the TAGs. Furthermore, in the temperate species of the montium species subgroup (D. subauraria, D. biauraria, D. triauraria and D. rufa) , the amount of saturated TAGs was smaller than the value expected on the assumption that fatty acids are randomly distributed in the TAGs, suggesting the non-random distribution of unsaturated fatty acids among TAGs. This may facilitate the lowering of the transition temperature of TAGs, and hence may be related to the ability of Drosophila to cope with temperate climates.

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It is well known that microorganisms can exist in every corner of natural environments, even if environments are extreme. As about 80% of biosphere in the earth's surface is 5℃ or colder, microorganisms must often encounter with cold environments. Most microorganisms may have evolved quite different ways of maintaining their membrane fluidity and metabolic activity constant, in response to changes in environmental temperature. The membrane fluidity is effectively altered by changes in fatty acid composition of lipids. After a shift-down in growth temperatures, the alteration of fatty acid composition such as increases in unsaturated, short-chain and branched fatty acids is mediated through the change in the activity of pre-existing enzymes and/or enzyme induction, depending on the species. By such means, microorganisms can regulate the activity of membrane-bound enzymes and transport systems. Simultaneously, a shift-down in growth temperatures induced increased rates of synthesis of more than a dozen proteins (so called cold-shock protein) in mesophiles, psychrotrophes and psychrophiles, in spite of the reduction in the rate of synthesis of most cellular proteins. Among these cold-shock proteins including seven proteins identified in E.coli, some are involved in transcription and translation. In the psychrophilic Vibrio sp., the temperature-related characteristics of protein synthesis in cells grown at 0℃ differed from those of cells grown at 13℃. This difference resulted from the modifications in the properties of the soluble fraction involved in protein synthesis. Such a modifications may be brought about by specific changes in the level of individual proteins whose the synthesis and degradation are induced by a shift in temperatures.

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A new ice-nucleating bacterium, KUIN-3, was isolated from strawberry leaves. Strain KUIN-3 was identified as Erwinia uredovora from its taxonomical characteristics. The extracellular ice-nucleating matter (EIM) produced by strain KUIN-3, was purified to apparent homogeneity by ultra filtration, sucrose density-gradient ultracentrifugation, and gel filtration. The purified EIM was spherical matter (about 250 nm) by examination using a transmission electron microscope. The ice-nucleating activity from the EIM was equal to that of the cells in this strain. It was demonstrated that the components of the EIM were lipid, protein, saccharide and polyamine. The enzyme treatments by protease K, α-mannosidase, β-galactosidase, phospholipase C, and diamine oxidase decreased the activity of the EIM as well as of the cells. The results suggested that polyamine was the most important component of the EIM. The application of the ice nucleation activity of the EIM to the freezing-foods was attempted.

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