IntroductionFreeze-drying and L-drying are popular methods of preserving microorganisms, because long-term viability is excellent in most cases and the storage and distribution requirements are simple. By plotting the survival curves of freeze-dried species sealed under high vacuum ( 1 Pa) and stored at 5 C in the dark, we previously found that the survival rates of Gram-positive bacteria immediately after freeze-drying and during storage were higher than those of Gram-negative bacteria (Miyamoto-Shinohara et al., 2008). In addition, the survival rate of the yeast Saccharomyces cerevisiae immediately after freeze-drying was lower than those of bacterial species, although S. cerevisiae survival rates were stable during storage (Miyamoto-Shinohara et al., 2000.To increase the survival rates of S. cerevisiae strains, we tested the applicability of L-drying, in which cells are desiccated by vacuum evaporation at room temperature. In contrast, during freeze-drying, cells are desiccated by sublimation. L-drying is effective for the long-term preservation of cultures sensitive to freezedrying (Malik, 1990(Malik, , 1999. In this research, yeast strains were L-dried according to the method of the Institute for Fermentation, Osaka (Banno et al., 1979), in which the cell suspension was dispensed into a glass ampoule (in the same way as for freeze-drying) and a cotton wool plug was inserted to prevent the temperature in the ampoule from falling to the freezing point (Iijima and Sakane, 1973).To clarify the mechanisms underlying tolerance to L-drying and freeze-drying, we investigated the survival of type strains of various yeast species. The survival J. Gen. Appl. Microbiol., 56, 107 119 (2010) We investigated

The mechanism of chain propagation in the living coordination polymerization of propene initiated by the soluble V(acac),/Al(qH,hCl catalyst was studied by lH and 13C NMR analyses of iodine-terminated polypropylenes of low molecular weights (M, = 630 to 3 200). A vanadium-carbon bond in the living polypropylene end reacts quantitatively with the iodine molecule to yield a new iodine-polymer bond. The lH and 13C NMR analyses of iodine-bonded polypropylene provide direct evidence on the stereochemistry of the first and last inserted propylene units and the structure of the living polypropylene end.

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The stereochemistry of syndiotactic-specific polymerization of propene with some soluble vanadium-based catalysts was investigated by ' H NMR analysis of iodine-bonded polypropylenes. The results of the 'H NMR analysis of chain-end groups confirm that the majority of active centers exists as secondary vanadium-carbon bonds during the chain propagation. The syndiotactic regularity of secondary-inserted propylene units is not influenced by the sequence length of a growing polymer chain, but dependent upon the kind of aluminium component used as co-catalyst.