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(1993). Enriching Euglena with Unsaturated Fatty Acids. Bioscience, Biotechnology, and Biochemistry: Vol. 57, No. 2, pp. 352-353.

Effects of pH shifted in the stationary phase on the chemical composition of Euglena gracilis cells were examined. When the cells that were cultivated at fixed pH of 4.5 reached stationary phase, the pH of the culture was shifted to 2.0–8.5, and the cultivation was continued for 24 hours more. Shifting pH to below 3.0 and between 6.5 and 7.5 increased cellular protein and decreased paramylon. The maximum content of protein in the cells was 77.5% when the pH was shifted to 7.5. At shifted pH of higher than 8.0, the protein content was greatly decreased and the paramylon content was greatly increased. This technique of shifting pH in the stationary phase did not improve the lipid content or fatty acid composition in Euglena for use as a feed for larval fish. Arachidonic acid, however, was found to be decreased in alkaline pH after shifting. This pH shifting technique that can improve the protein content in Euglena cells is useful for mass production of Euglena for use in the feed industry.

Since Euglena gracilis incorporate and accumulate n-3 highly unsaturated fatty acids (n-3 HUFA), the fatty acid composition of the cells can be controlled by supplementation of the fatty acids into growth media. Rotifers and Artemia were enriched with Euglena that ac-cumulated docosahexaenoic acid (DHA). The DHA content of the rotifers fed on more than 100000 cells/ml of Euglena increased in 12 hours. Also, the feeding density of more than 100000 cells/ml gave an increase in the DHA content in Artemia. As for Artemia, however, DHA was degraded fast after 6 hours of enrichment.A feeding experiment was conducted to evaluate the dietary value of living feed enriched with Euglena. Rotifers and Artemia enriched with Euglena contained much more DHA than those enriched with Nannochloropsis or methyl esters of n-3 HUFA. The larval red sea bream fed on living feed containing more DHA showed higher activity in the activity test.Thus, the dietary value of rotifers and Artemia to red sea bream was effectively improved by enrichment with Euglena. Euglena is expected to be profitable feed for the DHA enrichment of rotifers and Artemia.

High density cultured marine rotifer (Brachionus rotundiformis) fed on freshwater Chlorella was cultured secondarily with an emulsion of ethyl esters (65% DHA, 15% EPA) for EFA-enrichment, with or without freshwater Chlorella. Culture tanks (30 1, 20 1 working volume) set in a water bath (24 °C) were continuously supplied with air (2.501 m−1) or high-purity oxygen gas (1.25 1 nn−1). Samples for fatty acid composition analysis were collected at 0, 6, 12, and 24 hours after the inoculation of rotifer, followed by the monitoring of rotifer density, DO, NH4-N and pH.

A caries activity test solution, S-3105 developed by Nakamura et al., was examined in the field.Two hundred and thirty pre-school children, ranging in age from 3 to 5 years, were studied. Three dentists examined decayed, missing, and filled teeth, and debris score. Buccal plaque was sampled by swabbing with cotton, and then incubated in the solution at 37°C for 30 min. The color change was estimated as the test score. Then the relationship between oral status and the test was statistically analyzed.The test score showed positive significant correlations with d ratio, dmf, caries severity index (CSI), and ΔCSI.This solution seemed useful for caries activity tests in the field.

Significant positive correlations between protease activities in saliva and supragingival/subgingival calculus indices, periodontal pocket depth, or P-M-A index were confirmed. When the partial correlation was calculated, the subgingival calculus index correlated well with the sediment protease at pH 8.5, and the supragingival calculus index showed a significant correlation with the supernate protease at pH 4.5.

Publisher Summary This chapter presents an experiment that was conducted to convert β-N-acetylhexosaminidase B to A by the Golgi complex of the rat parotid gland. In this experiment, the homogenate was treated with cetyltrimethyl ammonium bromide at a final concentration of 0.4% at 4°C for 60 min. The mixture was centrifuged at 25,000 g for 40 min, and the supernate was concentrated with 80% saturation of ammonium sulfate. The sediment was dialyzed and applied to CM-cellulose column chromatography, which was equilibrated with 0.01 M phosphate buffer, pH 7.4. Hexosaminidase B was eluted with the buffer containing 0.125 M sodium chloride. In the isolating procedure of the Golgi apparatus, the supernate at 100,000 g for 30 min was boiled for 10 min. The boiled material was centrifuged at 15,000 g for 30 min, and the supernate was used as boiled juice.

Although the lierature contains many reports concerning the prevalence of dental caries in Japan, there is little information about the relationship between dental caries in preschool children and dental care by their mothers.Seven hundred and twenty-one children between the ages of 3 and 5 years were examined by three dentists. A mouth mirror and dental explorer were used to detect lesions. Questionnaires were given to thetr mothers concerning toothbrushing, between-meal eating and topical application of fluoride for children. The prevalence rates of clinical caries ranged from 90.4% for 3-year-olds to 97.5% for 5-year-olds. The mean number of decayed teeth was 7.5, 8.8 and 10.2 for 3-, 4- and 5-year-olds children, respectively. In statistic analysis, the group taking one between-meal snack a day showed a lower mean number of decayed teeth than another group (p