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To investigate the effect of deleting the genes encoding branched-chain amino acid transaminase (BAT2 gene) and pyruvate decarboxylase-like enzyme (THI3 gene) in Saccharomyces cerevisiae on the high alcohol content in Chinese rice wine, the diploid yeasts XF1-B (BAT2 gene deletion) and XF1-TB (THI3 and BAT2 gene deletion) were constructed using the Cre/loxP recombination system with the haploid XF1a7/XF1α6 of XF1 and haploid XF1a7-T/XF1α6-T of XF1-T (THI3 gene deletion) as the original strains. Chinese rice wine was fermented using XF1, XF1-B, and XF1-TB under the same conditions. The growth capability of XF1-B and XF1-TB was similar to that of XF1, and the basic fermentation capability was not significantly different. The isoamyl alcohol content decreased by 18.12% and 26.06%, the isobutanol content decreased by 35.21%and 18.83%, the n-propanol content increased by 15.42%and 32.75%, and the high alcohol content decreased by 15.65%and 15.28%to 269.59 and 270.77 mg/L in the Chinese rice wine brewed using XF1-B and XF1-TB, respectively, compared with those of wine brewed using XF1. The ratio of isoamyl alcohol/isobutanol was 3.24 and 2.34 in Chinese rice wine brewed using XF1-B and XF1-TB, respectively, representing a decrease of 27.78% compared with that of wine brewed using XF1. In summary, both XF1-B and XF1-TB effectively reduced the total higher alcohol content, and XF1-TB effectively reduced the ratio of isoamyl alcohol/isobutanol in Chinese rice wine. Hence, they can weaken the intoxication degree and improve the quality of Chinese rice wine [ABSTRACT FROM AUTHOR]

In order to effectively cure hepatitis B virus (HBV), we studied on fusion protein HBscFv-IFNgamma, which was connected with single-chain Fv against HBV surface antigen(HBscFv) and gamma-interferon(IFNgamma) of being used in clinic against HBV. Adopting overlap PCR, the hbscfv and the ifngamma were connected into hbscfv-ifngamma. Then the pPICZalphaA/(hbscfv-ifngamma)(1,2,4) of multi-copy recombinant plasmid were constructed and transformed into Pichia pastoris x33. The engineering strain x4 was screened from transformed x33 and could secretively express HBscFv-IFNgamma. The preliminary verification indicates that HBscFv-IFNgamma has the bioactivity of HBscFv and IFNgamma by SDS-PAGE, Western blotting and ELISA. The supernatant of culturing X4 was purified by 14F7 affinity chromatography to HBscFv-IFNgamma with purity of 95%-98%. The HBscFv-IFNgamma is able to bind 27.9% HBV surface antigen (HBsAg) in the serum of HBV transgenic mice, which shows the antibody of HBscFv-IFNgamma has bioactivity in vivo. Therefore HBscFv-IFNgamma can shed light on the development of a new promising HBV-targeted drug.