No abstract

A potent producer of D-arabitol was isolated by screening of natural sources and identified as Metschnikowia reukaufii AJ14787. Resting cells of this strain can efficiently produce D-arabitol from D-glucose with a weight yield of more than 60%, and can also produce D-arabitol from several other types of sugars such as polyols, ketoses, and aldoses. To improve productivity, various culture conditions such as temperature and the concentrations of D-glucose and nitrogen sources were examined. Under optimal conditions, 206 g/l of D-arabitol was produced from D-glucose with a weight yield of 52% in 100 hours.

No abstract

Demethylallosamidin (DMA, Fig. 1) was isolated as an insect chitinase inhibitor from the mycelia of Streptomyces sp. which is a producer of allosamidin (6). This new compound was also found to inhibit the Saccharomyces chitinase and the inhibitory activity on this enzyme was 100 times stronger than that of allosamidin ( Fig. 1) (8, 9). The yeast cells cultured with DMA were reported to show a clustered form compared with the cells grown without DMA. This observation supports a speculation that chitinase plays a role in the final fission of the septum that leads to cell separation. It has been speculated that fungal chitinase plays an important role in the growth and differentiation of all chitin-containing fungi (4, 5) . This communication deals with biological activities of DMA against a fungus, Geotrichum candidum which is known to show varied morphological changes during cultivation (1,2).A fungus, G. candidum AJ14212 (IFO 4597) was used throughout this work. For slide culture, 2% agar powder (pH 6.1) (Junsei Chemical Co., Tokyo, Japan) was used. For shake culture, Bacto YM Broth (pH 7.0 with NaOH or HCl) (Difco Laboratories, Detroit, MI, U.S.A.) was used. DMA was added to the above media at the concentration of 0.1, 1, 10, and 100,ug/ml respectively.One milliliter of the spore suspension prepared ordinarily was put in each vial and the vials were stocked in a refrigerator at -80°C as a seed culture. For agar slide culture, spore suspension was streaked on a thin agar gel and the agar was covered with a cover glass and this was incubated at 25°C for 2-6 days. For liquid