A yeast strain Rhodotorula sp.NJ-298,which was isolated from antarctic sea-ice,could produce carotenoids pigment,and the total production was 1986?g?g~(-1).UV-visible spectrum and LC/MS analysis indicated astaxanthin was the major component of the carotenoids,and HPLC analysis showed its content accounted for 81.9 % of total carotenoids productoin.Maximum astaxanthin production 6506 ?g?L~(-1) was obtained when the yeast was grown at steady-state phase.Optimum temperature for the strain grow was at 8℃,and sodium acetate and peptone were the best carbon and nitrogen sources for the astaxanthin production.Moreover,the pigment had strong activity of scavenging free radicals,and the IC_(50) was 0.40 ?g?mL~(-1) by DPPH assay.

Objective To investigate the prediction of maternal HBV transmission by breast milk of postpartum women with chronic HBV infection.Methods HBV DNA levels in serum and breast milk weredetected by fluorescent quantitative polymerase chain reaction in 64 postpartum women with chronic HBV infection.HBV DNA≥1.0×103copies/ml was defined as positive,and correlation analysis was conducted.Results HBV DNA positive rate was 78.1%and 62.5%in serum and breast milk respectively,with a HBV DNA range of 1.05×103～3.87 ×104copies/ml in breast milk.When HBV DNA in serum was 1.0×105～1.0×107copies/ml,the HBV DNA positive rate in breast milk reached to 94.9%;however,when HBV DNA in serum was 1.0×103～1.0×104copies/ml,the positive rate in breast milk was only 18.2%.Conclusion The HBV DNA positive rate of breast milk in postpartum women with chronic HBV infection is correlated with the HBV DNA levels in serum;and breast-feeding should be avoided for postpartum women with HBV DNA≥1.0×105copies/ml in the serum.So serum HBV DNA detection is necessary in antenatal care for women with chronic HBV infection.