为了进一步研究微生物富硒的能力,得到富硒能力较强的啤酒酵母,以啤酒酵母WX-01为出发菌,通过高浓度亚硒酸钠初筛,再经过常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变处理以及亚硒酸钠抗性平板筛选,观察菌株的...为了进一步研究微生物富硒的能力,得到富硒能力较强的啤酒酵母,以啤酒酵母WX-01为出发菌,通过高浓度亚硒酸钠初筛,再经过常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变处理以及亚硒酸钠抗性平板筛选,观察菌株的生长状况结合对其生物量与硒含量的测定,选育出一株富硒优势啤酒酵母。通过培养条件为添加质量浓度35 mg/L,加硒时间8 h,培养时间36 h,得到的酵母WX-1的生物量提高到(5192±36)mg/L,较原始菌株WX-01提高了201%,硒含量达到(1475±33)μg/g,较原始菌株提高了330%,其有机硒产量和转化率分别为7658μg/L和97.1%。扫描电镜分析酵母菌富集后表面有少量单质硒析出。另外红外光谱在特定区域出现不同强度的吸收峰表明酵母细胞参与了硒蛋白的合成。展开更多
分别采用酸法、酸碱法来提取啤酒酵母中的(1→3) β D 葡聚糖,然后对其产品进行多糖成分和紫外光谱分析。结果发现,在用c(CH3COOH)=0 5mol/L的水溶液提取啤酒酵母中的(1→3) β D 葡聚糖时,其产品中除含有葡聚糖外,还含有一定量的甘露...分别采用酸法、酸碱法来提取啤酒酵母中的(1→3) β D 葡聚糖,然后对其产品进行多糖成分和紫外光谱分析。结果发现,在用c(CH3COOH)=0 5mol/L的水溶液提取啤酒酵母中的(1→3) β D 葡聚糖时,其产品中除含有葡聚糖外,还含有一定量的甘露聚糖和蛋白质这两种成分。但先用c(NaOH)=1 0mol/L的水溶液提取,再用w(CH3COOH)=4%的醋酸溶液处理时,产品为高纯度的(1→3) β D 葡聚糖。此结论由傅立叶红外光谱和核磁共振碳谱得到进一步的证实。接着从其水解机理上阐述了产生上述两种不同结果的原因,从而说明了酸碱法是从啤酒酵母中提取(1→3) β D 葡聚糖的理想途径。展开更多
Yeast YIp\|type expression recombinant plasmid(pCMA2\|1) was constructed. The expression of α\|acetolactate decarboxylase gene from \%Bacillus subtilis\% was controled by \%CUP1\% promoter and its own terminator. The...Yeast YIp\|type expression recombinant plasmid(pCMA2\|1) was constructed. The expression of α\|acetolactate decarboxylase gene from \%Bacillus subtilis\% was controled by \%CUP1\% promoter and its own terminator. The recombinant plasmid pCMA2\|1 was introduced into the brewer’s yeast PJ3\|5. Transformants were selected using copper resistance as selected marker. The results of activity assay showed that PJ3\|5 didn’t produce α\|acetolactate decarboxylase(ALDC), where as the activity of α\|ALDC in transformants were induced by copper sulfate. The laboratory scale fermentation test confirmed that the total diacetyl concentration was reduced effectively by α\|ALDC in transformant.展开更多
The partial genomic library of Saccharomyce cerevisiae FL189 possessing strong flocculation ability was constructed using Yeast-E.coli shuttle plasmid YCp50 as vector.Recombinant plasmid containing flocculation gene w...The partial genomic library of Saccharomyce cerevisiae FL189 possessing strong flocculation ability was constructed using Yeast-E.coli shuttle plasmid YCp50 as vector.Recombinant plasmid containing flocculation gene was obtained by screening the growth of transformants on the selective medium and measurement flocculation,designated as pCF1.pCF1 was introduced into industrial yeast strain PJ208-5-15.Six transformants PJ208-5-15-1(pCF1)～PJ208-5-15-6(pCF1)possessing strong flocculation ability were obtained.The results of Southern blot and restriction endonuclease analysis showed that the insert is about 4.3kb and could hybridize with the probe (2.6kb EcoRV fragment of FLO1).Flocculation ability assay indicated that the transformants possess strong flocculation ability.Hence,the gene controlling flocculation phenotype exists in the cloned DNA fragment.The restriction endonuclease analysis and the sequence analysis of the insert DNA fragment are in progress.展开更多
文摘为了进一步研究微生物富硒的能力,得到富硒能力较强的啤酒酵母,以啤酒酵母WX-01为出发菌,通过高浓度亚硒酸钠初筛,再经过常压室温等离子体(atmospheric and room temperature plasma,ARTP)诱变处理以及亚硒酸钠抗性平板筛选,观察菌株的生长状况结合对其生物量与硒含量的测定,选育出一株富硒优势啤酒酵母。通过培养条件为添加质量浓度35 mg/L,加硒时间8 h,培养时间36 h,得到的酵母WX-1的生物量提高到(5192±36)mg/L,较原始菌株WX-01提高了201%,硒含量达到(1475±33)μg/g,较原始菌株提高了330%,其有机硒产量和转化率分别为7658μg/L和97.1%。扫描电镜分析酵母菌富集后表面有少量单质硒析出。另外红外光谱在特定区域出现不同强度的吸收峰表明酵母细胞参与了硒蛋白的合成。
文摘分别采用酸法、酸碱法来提取啤酒酵母中的(1→3) β D 葡聚糖,然后对其产品进行多糖成分和紫外光谱分析。结果发现,在用c(CH3COOH)=0 5mol/L的水溶液提取啤酒酵母中的(1→3) β D 葡聚糖时,其产品中除含有葡聚糖外,还含有一定量的甘露聚糖和蛋白质这两种成分。但先用c(NaOH)=1 0mol/L的水溶液提取,再用w(CH3COOH)=4%的醋酸溶液处理时,产品为高纯度的(1→3) β D 葡聚糖。此结论由傅立叶红外光谱和核磁共振碳谱得到进一步的证实。接着从其水解机理上阐述了产生上述两种不同结果的原因,从而说明了酸碱法是从啤酒酵母中提取(1→3) β D 葡聚糖的理想途径。
文摘Yeast YIp\|type expression recombinant plasmid(pCMA2\|1) was constructed. The expression of α\|acetolactate decarboxylase gene from \%Bacillus subtilis\% was controled by \%CUP1\% promoter and its own terminator. The recombinant plasmid pCMA2\|1 was introduced into the brewer’s yeast PJ3\|5. Transformants were selected using copper resistance as selected marker. The results of activity assay showed that PJ3\|5 didn’t produce α\|acetolactate decarboxylase(ALDC), where as the activity of α\|ALDC in transformants were induced by copper sulfate. The laboratory scale fermentation test confirmed that the total diacetyl concentration was reduced effectively by α\|ALDC in transformant.
文摘The partial genomic library of Saccharomyce cerevisiae FL189 possessing strong flocculation ability was constructed using Yeast-E.coli shuttle plasmid YCp50 as vector.Recombinant plasmid containing flocculation gene was obtained by screening the growth of transformants on the selective medium and measurement flocculation,designated as pCF1.pCF1 was introduced into industrial yeast strain PJ208-5-15.Six transformants PJ208-5-15-1(pCF1)～PJ208-5-15-6(pCF1)possessing strong flocculation ability were obtained.The results of Southern blot and restriction endonuclease analysis showed that the insert is about 4.3kb and could hybridize with the probe (2.6kb EcoRV fragment of FLO1).Flocculation ability assay indicated that the transformants possess strong flocculation ability.Hence,the gene controlling flocculation phenotype exists in the cloned DNA fragment.The restriction endonuclease analysis and the sequence analysis of the insert DNA fragment are in progress.
